Cary Clark | 8032b98 | 2017-07-28 11:04:54 -0400 | [diff] [blame^] | 1 | #Topic Path
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| 2 | #Alias Paths
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| 3 |
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| 4 | Path contains Lines and Curves which can be stroked or filled. Contour is
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| 5 | composed of a series of connected Lines and Curves. Path may contain zero,
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| 6 | one, or more Contours.
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| 7 | Each Line and Curve are described by Verb, Points, and optional Weight.
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| 8 |
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| 9 | Each pair of connected Lines and Curves share common Point; for instance, Path
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| 10 | containing two connected Lines are described the Verb sequence:
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| 11 | SkPath::kMove_Verb, SkPath::kLine_Verb, SkPath::kLine_Verb; and a Point sequence
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| 12 | with three entries, sharing
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| 13 | the middle entry as the end of the first Line and the start of the second Line.
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| 14 |
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| 15 | Path components Arc, Rect, Round_Rect, Circle, and Oval are composed of
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| 16 | Lines and Curves with as many Verbs and Points required
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| 17 | for an exact description. Once added to Path, these components may lose their
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| 18 | identity; although Path can be inspected to determine if it decribes a single
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| 19 | Rect, Oval, Round_Rect, and so on.
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| 20 |
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| 21 | #Example
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| 22 | #Height 192
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| 23 | #Description
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| 24 | Path contains three Contours: Line, Circle, and Quad. Line is stroked but
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| 25 | not filled. Circle is stroked and filled; Circle stroke forms a loop. Quad
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| 26 | is stroked and filled, but since it is not closed, Quad does not stroke a loop.
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| 27 | ##
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| 28 | void draw(SkCanvas* canvas) {
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| 29 | SkPaint paint;
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| 30 | paint.setAntiAlias(true);
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| 31 | SkPath path;
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| 32 | path.moveTo(124, 108);
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| 33 | path.lineTo(172, 24);
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| 34 | path.addCircle(50, 50, 30);
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| 35 | path.moveTo(36, 148);
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| 36 | path.quadTo(66, 188, 120, 136);
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| 37 | canvas->drawPath(path, paint);
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| 38 | paint.setStyle(SkPaint::kStroke_Style);
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| 39 | paint.setColor(SK_ColorBLUE);
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| 40 | paint.setStrokeWidth(3);
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| 41 | canvas->drawPath(path, paint);
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| 42 | }
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| 43 | ##
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| 44 |
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| 45 | Path contains a Fill_Type which determines whether overlapping Contours
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| 46 | form fills or holes. Fill_Type also determines whether area inside or outside
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| 47 | Lines and Curves is filled.
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| 48 |
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| 49 | #Example
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| 50 | #Height 192
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| 51 | #Description
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| 52 | Path is drawn filled, then stroked, then stroked and filled.
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| 53 | ##
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| 54 | void draw(SkCanvas* canvas) {
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| 55 | SkPaint paint;
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| 56 | paint.setAntiAlias(true);
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| 57 | SkPath path;
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| 58 | path.moveTo(36, 48);
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| 59 | path.quadTo(66, 88, 120, 36);
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| 60 | canvas->drawPath(path, paint);
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| 61 | paint.setStyle(SkPaint::kStroke_Style);
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| 62 | paint.setColor(SK_ColorBLUE);
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| 63 | paint.setStrokeWidth(8);
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| 64 | canvas->translate(0, 50);
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| 65 | canvas->drawPath(path, paint);
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| 66 | paint.setStyle(SkPaint::kStrokeAndFill_Style);
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| 67 | paint.setColor(SK_ColorRED);
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| 68 | canvas->translate(0, 50);
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| 69 | canvas->drawPath(path, paint);
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| 70 | }
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| 71 | ##
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| 72 |
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| 73 | Path contents are never shared. Copying Path by value effectively creates
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| 74 | a new Path independent of the original. Internally, the copy does not duplicate
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| 75 | its contents until it is edited, to reduce memory use and improve performance.
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| 76 |
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| 77 | #Subtopic Subtopics |
| 78 | #ToDo not all methods are in topics ## |
| 79 | #ToDo subtopics are not in topics ## |
| 80 | #Table |
| 81 | #Legend |
| 82 | # topics # description ## |
| 83 | #Legend ## |
| 84 | #Table ## |
| 85 | # Contour # A loop of lines and curves. ## |
| 86 | # Convexity # Whether Path contains simple loop. ## |
| 87 | # Last_Point # Final Point in Contour. ## |
| 88 | # Point_Array # All Points in Path. ## |
| 89 | # Verb # How Points and Contours are defined. ## |
| 90 | # Verb_Array # All Verbs in Path. ## |
| 91 | # Verb # How Points and Contours are defined. ## |
| 92 | # Weight # Strength of control Point in Conic. ## |
| 93 | #Subtopic ## |
| 94 |
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| 95 |
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| 96 | #Subtopic Contour |
| 97 | #Alias Contours |
| 98 | Contour contains one or more Verbs, and as many Points as |
| 99 | are required to satisfy Verb_Array. First Verb in Path is always |
| 100 | SkPath::kMove_Verb; each SkPath::kMove_Verb that follows starts a new Contour. |
| 101 | |
| 102 | #Example |
| 103 | #Description
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| 104 | Each SkPath::moveTo starts a new Contour, and content after SkPath::close()
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| 105 | also starts a new Contour. Since SkPath::conicTo wasn't preceded by
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| 106 | SkPath::moveTo, the first Point of the third Contour starts at the last Point
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| 107 | of the second Contour.
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| 108 | ##
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| 109 | #Height 192
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| 110 | SkPaint paint;
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| 111 | paint.setAntiAlias(true);
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| 112 | canvas->drawString("1st contour", 150, 100, paint);
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| 113 | canvas->drawString("2nd contour", 130, 160, paint);
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| 114 | canvas->drawString("3rd contour", 40, 30, paint);
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| 115 | paint.setStyle(SkPaint::kStroke_Style);
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| 116 | SkPath path;
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| 117 | path.moveTo(124, 108);
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| 118 | path.lineTo(172, 24);
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| 119 | path.moveTo(36, 148);
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| 120 | path.quadTo(66, 188, 120, 136);
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| 121 | path.close();
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| 122 | path.conicTo(70, 20, 110, 40, 0.6f);
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| 123 | canvas->drawPath(path, paint);
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| 124 | ## |
| 125 | |
| 126 | If final Verb in Contour is SkPath::kClose_Verb, Line connects Last_Point in |
| 127 | Contour with first Point. A closed Contour, stroked, draws |
| 128 | Paint_Stroke_Join at Last_Point and first Point. Without SkPath::kClose_Verb |
| 129 | as final Verb, Last_Point and first Point are not connected; Contour |
| 130 | remains open. An open Contour, stroked, draws Paint_Stroke_Cap at |
| 131 | Last_Point and first Point. |
| 132 | |
| 133 | #Example |
| 134 | #Height 160
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| 135 | #Description
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| 136 | Path is drawn stroked, with an open Contour and a closed Contour.
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| 137 | ##
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| 138 | void draw(SkCanvas* canvas) {
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| 139 | SkPaint paint;
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| 140 | paint.setAntiAlias(true);
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| 141 | paint.setStyle(SkPaint::kStroke_Style);
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| 142 | paint.setStrokeWidth(8);
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| 143 | SkPath path;
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| 144 | path.moveTo(36, 48);
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| 145 | path.quadTo(66, 88, 120, 36);
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| 146 | canvas->drawPath(path, paint);
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| 147 | path.close();
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| 148 | canvas->translate(0, 50);
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| 149 | canvas->drawPath(path, paint);
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| 150 | }
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| 151 | ## |
| 152 | |
| 153 | #Subtopic Zero_Length |
| 154 | #Alias Zero_Length_Contour |
| 155 | Contour length is distance traveled from first Point to Last_Point, |
| 156 | plus, if Contour is closed, distance from Last_Point to first Point. |
| 157 | Even if Contour length is zero, stroked Lines are drawn if Paint_Stroke_Cap |
| 158 | makes them visible. |
| 159 | |
| 160 | #Example |
| 161 | #Height 64
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| 162 | SkPaint paint;
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| 163 | paint.setAntiAlias(true);
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| 164 | paint.setStyle(SkPaint::kStroke_Style);
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| 165 | paint.setStrokeWidth(8);
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| 166 | paint.setStrokeCap(SkPaint::kRound_Cap);
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| 167 | SkPath path;
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| 168 | path.moveTo(36, 48);
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| 169 | path.lineTo(36, 48);
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| 170 | canvas->drawPath(path, paint);
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| 171 | path.reset();
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| 172 | paint.setStrokeCap(SkPaint::kSquare_Cap);
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| 173 | path.moveTo(56, 48);
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| 174 | path.close();
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| 175 | canvas->drawPath(path, paint); |
| 176 | ## |
| 177 | |
| 178 | #Subtopic Zero_Length ## |
| 179 | |
| 180 | #Subtopic Contour ## |
| 181 |
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| 182 | # ------------------------------------------------------------------------------
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| 183 | |
| 184 | #Class SkPath
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| 185 |
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| 186 | #Topic Overview
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| 187 |
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| 188 | #Subtopic Constants |
| 189 | #ToDo incomplete ## |
| 190 | #Table |
| 191 | #Legend |
| 192 | # constants # description ## |
| 193 | #Legend ## |
| 194 | # AddPathMode # Sets addPath options. ## |
| 195 | # ArcSize # Sets arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep, SkScalar x, SkScalar y) options. ## |
| 196 | # Convexity # Returns if Path is convex or concave. ## |
| 197 | # Direction # Sets Contour clockwise or counterclockwise. ## |
| 198 | # FillType # Sets winding rule and inverse fill. ## |
| 199 | # SegmentMask |
| 200 | # Verb # Controls how Path Points are interpreted. ## |
| 201 | #Table ## |
| 202 | #Subtopic ## |
| 203 |
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| 204 | #Subtopic Classes_and_Structs |
| 205 | #Table |
| 206 | #Legend |
| 207 | # class or struct # description ## |
| 208 | #Legend ## |
| 209 | # Iter # Iterates through lines and curves, skipping degenerates. ## |
| 210 | # RawIter # Iterates through lines and curves, including degenerates. ## |
| 211 | #Table ## |
| 212 | #Subtopic ## |
| 213 |
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| 214 | #Subtopic Constructors |
| 215 | #Table |
| 216 | #Legend |
| 217 | # # description ## |
| 218 | #Legend ## |
| 219 | # SkPath() # Constructs with default values. ## |
| 220 | # SkPath(const SkPath& path) # Makes a shallow copy. ## |
| 221 | # ~SkPath() # Decreases Reference_Count of owned objects. ## |
| 222 | #Table ## |
| 223 | #Subtopic ## |
| 224 | |
| 225 | #Subtopic Operators |
| 226 | #Table |
| 227 | #Legend |
| 228 | # operator # description ## |
| 229 | #Legend ## |
| 230 | # operator=(const SkPath& path) # Makes a shallow copy. ## |
| 231 | # operator==(const SkPath& a, const SkPath& b) # Compares paths for equality. ## |
| 232 | # operator!=(const SkPath& a, const SkPath& b) # Compares paths for inequality. ## |
| 233 | #Table ## |
| 234 | #Subtopic ## |
| 235 |
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| 236 | #Subtopic Member_Functions
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| 237 | #Table
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| 238 | #Legend
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| 239 | # function # description ##
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| 240 | #Legend ##
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| 241 | # ConvertConicToQuads # Approximates Conic with Quad array. ##
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| 242 | # ConvertToNonInverseFillType # Returns Fill_Type representing inside geometry. ##
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| 243 | # IsCubicDegenerate # Returns if Cubic is very small. ##
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| 244 | # IsInverseFillType # Returns if Fill_Type represents outside geometry. ##
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| 245 | # IsLineDegenerate # Returns if Line is very small. ##
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| 246 | # IsQuadDegenerate # Returns if Quad is very small. ##
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| 247 | # addArc # Adds one Contour containing Arc. ##
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| 248 | # addCircle # Adds one Contour containing Circle. ##
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| 249 | # addOval # Adds one Contour containing Oval. ##
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| 250 | # addPath # Adds contents of Path. ##
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| 251 | # addPoly # Adds one Contour containing connected lines. ##
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| 252 | # addRRect # Adds one Contour containing Round_Rect. ##
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| 253 | # addRect # Adds one Contour containing Rect. ##
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| 254 | # addRoundRect # Adds one Contour containing Round_Rect with common corner radii. ##
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| 255 | # arcTo # Appends Arc. ##
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| 256 | # close() # Makes last Contour a loop. ##
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| 257 | # computeTightBounds # Returns extent of geometry. ##
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| 258 | # conicTo # Appends Conic. ##
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| 259 | # conservativelyContainsRect # Returns true if Rect may be inside. ##
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| 260 | # contains() # Returns if Point is in fill area. ##
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| 261 | # countPoints # Returns Point_Array length. ##
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| 262 | # countVerbs # Returns Verb_Array length. ##
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| 263 | # cubicTo # Appends Cubic. ##
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| 264 | # dump() # Sends text representation using floats to stdout. ##
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| 265 | # dumpHex # Sends text representation using hexadecimal to stdout. ##
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| 266 | # experimentalValidateRef # Experimental; debugging only. ##
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| 267 | # getBounds # Returns maximum and minimum of Point_Array. ##
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| 268 | # getConvexity # Returns geometry convexity, computing if necessary. ##
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| 269 | # getConvexityOrUnknown # Returns geometry convexity if known. ##
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| 270 | # getFillType # Returns Fill_Type: winding, even-odd, inverse. ##
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| 271 | # getGenerationID # Returns unique ID. ##
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| 272 | # getLastPt # Returns Last_Point. ##
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| 273 | # getPoint # Returns entry from Point_Array. ##
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| 274 | # getPoints # Returns Point_Array. ##
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| 275 | # getSegmentMasks # Returns types in Verb_Array. ##
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| 276 | # getVerbs # Returns Verb_Array. ##
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| 277 | # incReserve # Hint to reserve space for additional data. ##
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| 278 | # interpolate() # Interpolates between Path pair. ##
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| 279 | # isConvex # Returns if geometry is convex. ##
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| 280 | # isEmpty # Returns if verb count is zero. ##
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| 281 | # isFinite # Returns if all Point values are finite. ##
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| 282 | # isInterpolatable # Returns if pair contains equal counts of Verb_Array and Weights. ##
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| 283 | # isInverseFillType # Returns if Fill_Type fills outside geometry. ##
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| 284 | # isLastContourClosed # Returns if final Contour forms a loop. ##
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| 285 | # isLine # Returns if describes Line. ##
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| 286 | # isNestedFillRects # Returns if describes Rect pair, one inside the other. ##
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| 287 | # isOval # Returns if describes Oval. ##
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| 288 | # isRRect # Returns if describes Round_Rect. ##
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| 289 | # isRect # Returns if describes Rect. ##
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| 290 | # isVolatile # Returns if Device should not cache. ##
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| 291 | # lineTo # Appends Line. ##
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| 292 | # moveTo # Starts Contour. ##
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| 293 | # offset() # Translates Point_Array. ##
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| 294 | # quadTo # Appends Quad. ##
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| 295 | # rArcTo # Appends Arc relative to Last_Point. ##
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| 296 | # rConicTo # Appends Conic relative to Last_Point. ##
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| 297 | # rCubicTo # Appends Cubic relative to Last_Point. ##
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| 298 | # rLineTo # Appends Line relative to Last_Point. ##
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| 299 | # rMoveTo # Starts Contour relative to Last_Point. ##
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| 300 | # rQuadTo # Appends Quad relative to Last_Point. ##
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| 301 | # readFromMemory # Initialize from buffer. ##
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| 302 | # reset() # Removes Verb_Array, Point_Array, and Weights; frees memory. ##
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| 303 | # reverseAddPath # Adds contents of Path back to front. ##
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| 304 | # rewind() # Removes Verb_Array, Point_Array, and Weights; leaves memory allocated. ##
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| 305 | # setConvexity # Sets if geometry is convex to avoid future computation. ##
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| 306 | # setFillType # Sets Fill_Type: winding, even-odd, inverse. ##
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| 307 | # setIsConvex # Deprecated. ##
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| 308 | # setIsVolatile # Sets if Device should not cache. ##
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| 309 | # setLastPt # Replaces Last_Point. ##
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| 310 | # swap() # Exchanges Path pair. ##
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| 311 | # toggleInverseFillType # Toggles Fill_Type between inside and outside geometry. ##
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| 312 | # transform() # Applies Matrix to Point_Array and Weights. ##
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| 313 | # unique() # Returns if data has single owner. ##
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| 314 | # updateBoundsCache # Refresh result of getBounds. ##
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| 315 | # writeToMemory # Copy data to buffer. ##
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| 316 | #Table ##
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| 317 | #Subtopic Path_Member_Functions ##
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| 318 | #Topic Overview ##
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| 319 |
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| 320 | #Subtopic Verb |
| 321 | #Alias Verbs |
| 322 | |
| 323 | #Enum Verb
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| 324 |
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| 325 | #Code
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| 326 | enum Verb {
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| 327 | kMove_Verb
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| 328 | kLine_Verb
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| 329 | kQuad_Verb
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| 330 | kConic_Verb
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| 331 | kCubic_Verb
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| 332 | kClose_Verb
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| 333 | kDone_Verb
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| 334 | };
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| 335 | ##
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| 336 |
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| 337 | Verb instructs Path how to interpret one or more Point and optional Weight; |
| 338 | manage Contour, and terminate Path. |
| 339 | |
| 340 | #Const kMove_Verb 0
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| 341 | Starts new Contour at next Point.
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| 342 | ##
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| 343 | #Const kLine_Verb 1
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| 344 | Adds Line from Last_Point to next Point.
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| 345 | Line is a straight segment from Point to Point.
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| 346 | ##
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| 347 | #Const kQuad_Verb 2
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| 348 | Adds Quad from Last_Point, using control Point, and end Point.
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| 349 | Quad is a parabolic section within tangents from Last_Point to control Point,
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| 350 | and control Point to end Point.
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| 351 | ##
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| 352 | #Const kConic_Verb 3
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| 353 | Adds Conic from Last_Point, using control Point, end Point, and Weight.
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| 354 | Conic is a elliptical, parabolic, or hyperbolic section within tangents
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| 355 | from Last_Point to control Point, and control Point to end Point, constrained
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| 356 | by Weight. Weight less than one is elliptical; equal to one is parabolic
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| 357 | (and identical to Quad); greater than one hyperbolic.
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| 358 | ##
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| 359 | #Const kCubic_Verb 4
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| 360 | Adds Cubic from Last_Point, using two control Points, and end Point.
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| 361 | Cubic is a third-order Bezier section within tangents from Last_Point to
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| 362 | first control Point, and from second control Point to end Point.
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| 363 | ##
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| 364 | #Const kClose_Verb 5
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| 365 | Closes Contour, connecting Last_Point to kMove_Verb Point.
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| 366 | ##
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| 367 | #Const kDone_Verb 6
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| 368 | Terminates Path. Not in Verb_Array, but returned by Path iterator.
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| 369 | ## |
| 370 | |
| 371 | Each Verb has zero or more Points stored in Path. |
| 372 | Path iterator returns complete curve descriptions, duplicating shared Points |
| 373 | for consecutive entries. |
| 374 | |
| 375 | #Table |
| 376 | #Legend |
| 377 | # Verb # Allocated Points # Iterated Points # Weights ## |
| 378 | ## |
| 379 | # kMove_Verb # 1 # 1 # 0 ## |
| 380 | # kLine_Verb # 1 # 2 # 0 ## |
| 381 | # kQuad_Verb # 2 # 3 # 0 ## |
| 382 | # kConic_Verb # 2 # 3 # 1 ## |
| 383 | # kCubic_Verb # 3 # 4 # 0 ## |
| 384 | # kClose_Verb # 0 # 1 # 0 ## |
| 385 | # kDone_Verb # -- # 0 # 0 ## |
| 386 | ## |
| 387 |
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| 388 | #Example
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| 389 | void draw(SkCanvas* canvas) {
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| 390 | SkPath path;
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| 391 | path.lineTo(20, 20);
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| 392 | path.quadTo(-10, -10, 30, 30);
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| 393 | path.close();
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| 394 | path.cubicTo(1, 2, 3, 4, 5, 6);
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| 395 | path.conicTo(0, 0, 0, 0, 2);
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| 396 | uint8_t verbs[7];
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| 397 | int count = path.getVerbs(verbs, (int) SK_ARRAY_COUNT(verbs));
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| 398 | const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close" };
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| 399 | SkDebugf("verb count: %d\nverbs: ", count);
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| 400 | for (int i = 0; i < count; ++i) {
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| 401 | SkDebugf("k%s_Verb ", verbStr[verbs[i]]);
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| 402 | }
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| 403 | SkDebugf("\n");
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| 404 | }
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| 405 | #StdOut
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| 406 | verb count: 7
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| 407 | verbs: kMove_Verb kLine_Verb kQuad_Verb kClose_Verb kMove_Verb kCubic_Verb kConic_Verb
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| 408 | ##
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| 409 | ##
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| 410 |
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| 411 | #Enum Verb ##
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| 412 | #Subtopic Verb ##
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| 413 |
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| 414 | # ------------------------------------------------------------------------------
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| 415 | #Subtopic Direction
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| 416 | #Alias Directions
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| 417 |
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| 418 | #Enum Direction
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| 419 |
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| 420 | #Code
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| 421 | enum Direction {
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| 422 | kCW_Direction
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| 423 | kCCW_Direction
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| 424 | };
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| 425 | ##
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| 426 |
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| 427 | Direction describes whether Contour is clockwise or counterclockwise.
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| 428 | When Path contains multiple overlapping Contours, Direction together with
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| 429 | Fill_Type determines whether overlaps are filled or form holes.
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| 430 |
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| 431 | Direction also determines how Contour is measured. For instance, dashing
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| 432 | measures along Path to determine where to start and stop stroke; Direction
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| 433 | will change dashed results as it steps clockwise or counterclockwise.
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| 434 |
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| 435 | Closed Contours like Rect, Round_Rect, Circle, and Oval added with
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| 436 | kCW_Direction travel clockwise; the same added with kCCW_Direction
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| 437 | travel counterclockwise.
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| 438 |
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| 439 | #Const kCW_Direction
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| 440 | Contour travels in a clockwise direction.
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| 441 | ##
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| 442 | #Const kCCW_Direction
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| 443 | Contour travels in a counterclockwise direction.
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| 444 | ##
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| 445 |
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| 446 |
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| 447 | #Example
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| 448 | #Height 100
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| 449 | void draw(SkCanvas* canvas) {
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| 450 | const SkPoint arrow[] = { {40, -5}, {45, 0}, {40, 5} };
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| 451 | const SkRect rect = {10, 10, 90, 90};
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| 452 | SkPaint rectPaint;
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| 453 | rectPaint.setAntiAlias(true);
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| 454 | SkPaint textPaint(rectPaint);
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| 455 | textPaint.setTextAlign(SkPaint::kCenter_Align);
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| 456 | rectPaint.setStyle(SkPaint::kStroke_Style);
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| 457 | SkPaint arrowPaint(rectPaint);
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| 458 | SkPath arrowPath;
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| 459 | arrowPath.addPoly(arrow, SK_ARRAY_COUNT(arrow), true);
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| 460 | arrowPaint.setPathEffect(SkPath1DPathEffect::Make(arrowPath, 320, 0,
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| 461 | SkPath1DPathEffect::kRotate_Style));
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| 462 | for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
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| 463 | canvas->drawRect(rect, rectPaint);
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| 464 | for (unsigned start : { 0, 1, 2, 3 } ) {
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| 465 | SkPath path;
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| 466 | path.addRect(rect, direction, start);
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| 467 | canvas->drawPath(path, arrowPaint);
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| 468 | }
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| 469 | canvas->drawString(SkPath::kCW_Direction == direction ? "CW" : "CCW", rect.centerX(),
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| 470 | rect.centerY(), textPaint);
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| 471 | canvas->translate(120, 0);
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| 472 | }
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| 473 | }
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| 474 | ##
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| 475 |
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| 476 | #SeeAlso arcTo rArcTo isRect isNestedFillRects addRect addOval
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| 477 |
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| 478 | #Enum Direction ##
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| 479 | #Subtopic Direction ##
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| 480 |
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| 481 | # ------------------------------------------------------------------------------
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| 482 |
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| 483 | #Method SkPath()
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| 484 |
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| 485 | By default, Path has no Verbs, no Points, and no Weights.
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| 486 | Fill_Type is set to kWinding_FillType.
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| 487 |
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| 488 | #Return empty Path. ##
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| 489 |
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| 490 | #Example
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| 491 | SkPath path;
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| 492 | SkDebugf("path is " "%s" "empty", path.isEmpty() ? "" : "not ");
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| 493 | #StdOut
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| 494 | path is empty
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| 495 | ##
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| 496 | ##
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| 497 |
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| 498 | #SeeAlso reset rewind
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| 499 |
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| 500 | ##
|
| 501 |
|
| 502 | # ------------------------------------------------------------------------------
|
| 503 |
|
| 504 | #Method SkPath(const SkPath& path)
|
| 505 |
|
| 506 | Copy constructor makes two paths identical by value. Internally, path and
|
| 507 | the returned result share pointer values. The underlying Verb_Array, Point_Array
|
| 508 | and Weights are copied when modified.
|
| 509 |
|
| 510 | Creating a Path copy is very efficient and never allocates memory.
|
| 511 | Paths are always copied by value from the interface; the underlying shared
|
| 512 | pointers are not exposed.
|
| 513 |
|
| 514 | #Param path Path to copy by value. ##
|
| 515 |
|
| 516 | #Return Copy of Path. ##
|
| 517 |
|
| 518 | #Example
|
| 519 | #Description
|
| 520 | Modifying one path does not effect another, even if they started as copies
|
| 521 | of each other.
|
| 522 | ##
|
| 523 | SkPath path;
|
| 524 | path.lineTo(20, 20);
|
| 525 | SkPath path2(path);
|
| 526 | path2.close();
|
| 527 | SkDebugf("path verbs: %d\n", path.countVerbs());
|
| 528 | SkDebugf("path2 verbs: %d\n", path2.countVerbs());
|
| 529 | path.reset();
|
| 530 | SkDebugf("after reset\n" "path verbs: %d\n", path.countVerbs());
|
| 531 | SkDebugf("path2 verbs: %d\n", path2.countVerbs());
|
| 532 | #StdOut
|
| 533 | path verbs: 2
|
| 534 | path2 verbs: 3
|
| 535 | after reset
|
| 536 | path verbs: 0
|
| 537 | path2 verbs: 3
|
| 538 | ##
|
| 539 | ##
|
| 540 |
|
| 541 | #SeeAlso operator=(const SkPath& path)
|
| 542 |
|
| 543 | ##
|
| 544 |
|
| 545 | # ------------------------------------------------------------------------------
|
| 546 |
|
| 547 | #Method ~SkPath()
|
| 548 |
|
| 549 | Releases ownership of any shared data and deletes data if Path is sole owner.
|
| 550 |
|
| 551 | #Example
|
| 552 | #Description
|
| 553 | delete calls Path destructor, but copy of original in path2 is unaffected.
|
| 554 | ##
|
| 555 | void draw(SkCanvas* canvas) {
|
| 556 | SkPath* path = new SkPath();
|
| 557 | path->lineTo(20, 20);
|
| 558 | SkPath path2(*path);
|
| 559 | delete path;
|
| 560 | SkDebugf("path2 is " "%s" "empty", path2.isEmpty() ? "" : "not ");
|
| 561 | }
|
| 562 | ##
|
| 563 |
|
| 564 | #SeeAlso SkPath() SkPath(const SkPath& path) operator=(const SkPath& path)
|
| 565 |
|
| 566 | ##
|
| 567 |
|
| 568 | # ------------------------------------------------------------------------------
|
| 569 |
|
| 570 | #Method SkPath& operator=(const SkPath& path)
|
| 571 |
|
| 572 | Path assignment makes two paths identical by value. Internally, assignment
|
| 573 | shares pointer values. The underlying Verb_Array, Point_Array and Weights
|
| 574 | are copied when modified.
|
| 575 |
|
| 576 | Copying Paths by assignment is very efficient and never allocates memory.
|
| 577 | Paths are always copied by value from the interface; the underlying shared
|
| 578 | pointers are not exposed.
|
| 579 |
|
| 580 | #Param path Verb_Array, Point_Array, Weights, amd Fill_Type to copy. ##
|
| 581 |
|
| 582 | #Return Path copied by value. ##
|
| 583 |
|
| 584 | #Example
|
| 585 | SkPath path1;
|
| 586 | path1.addRect({10, 20, 30, 40});
|
| 587 | SkPath path2 = path1;
|
| 588 | const SkRect& b1 = path1.getBounds();
|
| 589 | SkDebugf("path1 bounds = %g, %g, %g, %g\n", b1.fLeft, b1.fTop, b1.fRight, b1.fBottom);
|
| 590 | const SkRect& b2 = path2.getBounds();
|
| 591 | SkDebugf("path2 bounds = %g, %g, %g, %g\n", b2.fLeft, b2.fTop, b2.fRight, b2.fBottom);
|
| 592 | #StdOut
|
| 593 | path1 bounds = 10, 20, 30, 40
|
| 594 | path2 bounds = 10, 20, 30, 40
|
| 595 | #StdOut ##
|
| 596 | ##
|
| 597 |
|
| 598 | #SeeAlso swap() SkPath(const SkPath& path)
|
| 599 |
|
| 600 | ##
|
| 601 |
|
| 602 | # ------------------------------------------------------------------------------
|
| 603 |
|
| 604 | #Method friend SK_API bool operator==(const SkPath& a, const SkPath& b)
|
| 605 |
|
| 606 | Compares a and b; returns true if Fill_Type, Verb_Array, Point_Array, and Weights
|
| 607 | are equivalent.
|
| 608 |
|
| 609 | #Param a Path to compare. ##
|
| 610 | #Param b Path to compare. ##
|
| 611 |
|
| 612 | #Return true if Path pair are equivalent. ##
|
| 613 |
|
| 614 | #Example
|
| 615 | #Description
|
| 616 | Rewind removes Verb_Array but leaves storage; since storage is not compared,
|
| 617 | Path pair are equivalent.
|
| 618 | ##
|
| 619 | void draw(SkCanvas* canvas) {
|
| 620 | auto debugster = [](const char* prefix, const SkPath& a, const SkPath& b) -> void {
|
| 621 | SkDebugf("%s one %c= two\n", prefix, a == b ? '=' : '!');
|
| 622 | };
|
| 623 | SkPath one;
|
| 624 | SkPath two;
|
| 625 | debugster("empty", one, two);
|
| 626 | one.moveTo(0, 0);
|
| 627 | debugster("moveTo", one, two);
|
| 628 | one.rewind();
|
| 629 | debugster("rewind", one, two);
|
| 630 | one.moveTo(0, 0);
|
| 631 | one.reset();
|
| 632 | debugster("reset", one, two);
|
| 633 | }
|
| 634 | #StdOut
|
| 635 | empty one == two
|
| 636 | moveTo one != two
|
| 637 | rewind one == two
|
| 638 | reset one == two
|
| 639 | ##
|
| 640 | ##
|
| 641 |
|
| 642 | ##
|
| 643 |
|
| 644 | # ------------------------------------------------------------------------------
|
| 645 |
|
| 646 | #Method friend bool operator!=(const SkPath& a, const SkPath& b)
|
| 647 |
|
| 648 | Compares a and b; returns true if Fill_Type, Verb_Array, Point_Array, and Weights
|
| 649 | are not equivalent.
|
| 650 |
|
| 651 | #Param a Path to compare. ##
|
| 652 | #Param b Path to compare. ##
|
| 653 |
|
| 654 | #Return true if Path pair are not equivalent. ##
|
| 655 |
|
| 656 | #Example
|
| 657 | #Description
|
| 658 | Path pair are equal though their convexity is not equal.
|
| 659 | ##
|
| 660 | void draw(SkCanvas* canvas) {
|
| 661 | auto debugster = [](const char* prefix, const SkPath& a, const SkPath& b) -> void {
|
| 662 | SkDebugf("%s one %c= two\n", prefix, a != b ? '!' : '=');
|
| 663 | };
|
| 664 | SkPath one;
|
| 665 | SkPath two;
|
| 666 | debugster("empty", one, two);
|
| 667 | one.addRect({10, 20, 30, 40});
|
| 668 | two.addRect({10, 20, 30, 40});
|
| 669 | debugster("addRect", one, two);
|
| 670 | one.setConvexity(SkPath::kConcave_Convexity);
|
| 671 | debugster("setConvexity", one, two);
|
| 672 | SkDebugf("convexity %c=\n", one.getConvexity() == two.getConvexity() ? '=' : '!');
|
| 673 | }
|
| 674 | #StdOut
|
| 675 | empty one == two
|
| 676 | addRect one == two
|
| 677 | setConvexity one == two
|
| 678 | convexity !=
|
| 679 | ##
|
| 680 | ##
|
| 681 |
|
| 682 | ##
|
| 683 |
|
| 684 | # ------------------------------------------------------------------------------
|
| 685 |
|
| 686 | #Method bool isInterpolatable(const SkPath& compare) const
|
| 687 |
|
| 688 | Return true if Paths contain equal Verbs and equal Weights.
|
| 689 | If Paths contain one or more Conics, the Weights must match.
|
| 690 |
|
| 691 | conicTo may add different Verbs depending on Conic_Weight, so it is not
|
| 692 | trival to interpolate a pair of Paths containing Conics with different
|
| 693 | Conic_Weight values.
|
| 694 |
|
| 695 | #Param compare Path to compare. ##
|
| 696 |
|
| 697 | #Return true if Paths Verb_Array and Weights are equivalent. ##
|
| 698 |
|
| 699 | #Example
|
| 700 | SkPath path, path2;
|
| 701 | path.moveTo(20, 20);
|
| 702 | path.lineTo(40, 40);
|
| 703 | path.lineTo(20, 20);
|
| 704 | path.lineTo(40, 40);
|
| 705 | path.close();
|
| 706 | path2.addRect({20, 20, 40, 40});
|
| 707 | SkDebugf("paths are " "%s" "interpolatable", path.isInterpolatable(path2) ? "" : "not ");
|
| 708 | #StdOut
|
| 709 | paths are interpolatable
|
| 710 | ##
|
| 711 | ##
|
| 712 |
|
| 713 | #SeeAlso isInterpolatable
|
| 714 |
|
| 715 | ##
|
| 716 |
|
| 717 | # ------------------------------------------------------------------------------
|
| 718 |
|
| 719 | #Method bool interpolate(const SkPath& ending, SkScalar weight, SkPath* out) const
|
| 720 |
|
| 721 | Interpolate between Paths with equal sized Point_Arrays.
|
| 722 | Copy Verb_Array and Weights to out,
|
| 723 | and set out Point_Array to a weighted average of this Point_Array and ending
|
| 724 | Point_Array, using the formula:
|
| 725 | #Formula
|
| 726 | (this->points * weight) + ending->points * (1 - weight)
|
| 727 | ##
|
| 728 |
|
| 729 | interpolate() returns false and leaves out unchanged if Point_Array is not
|
| 730 | the same size as ending Point_Array. Call isInterpolatable to check Path
|
| 731 | compatibility prior to calling interpolate().
|
| 732 |
|
| 733 | #Param ending Point_Array averaged with this Point_Array. ##
|
| 734 | #Param weight Most useful when between zero (ending Point_Array) and
|
| 735 | one (this Point_Array); will work with values outside of this
|
| 736 | range.
|
| 737 | ##
|
| 738 | #Param out ##
|
| 739 |
|
| 740 | #Return true if Paths contain same number of Points. ##
|
| 741 |
|
| 742 | #Example
|
| 743 | #Height 60
|
| 744 | void draw(SkCanvas* canvas) {
|
| 745 | SkPaint paint;
|
| 746 | paint.setAntiAlias(true);
|
| 747 | paint.setStyle(SkPaint::kStroke_Style);
|
| 748 | SkPath path, path2;
|
| 749 | path.moveTo(20, 20);
|
| 750 | path.lineTo(40, 40);
|
| 751 | path.lineTo(20, 40);
|
| 752 | path.lineTo(40, 20);
|
| 753 | path.close();
|
| 754 | path2.addRect({20, 20, 40, 40});
|
| 755 | for (SkScalar i = 0; i <= 1; i += 1.f / 6) {
|
| 756 | SkPath interp;
|
| 757 | path.interpolate(path2, i, &interp);
|
| 758 | canvas->drawPath(interp, paint);
|
| 759 | canvas->translate(30, 0);
|
| 760 | }
|
| 761 | }
|
| 762 | ##
|
| 763 |
|
| 764 | #SeeAlso isInterpolatable
|
| 765 |
|
| 766 | ##
|
| 767 |
|
| 768 | # ------------------------------------------------------------------------------
|
| 769 |
|
| 770 | #Method bool unique() const
|
| 771 |
|
| 772 | #Private
|
| 773 | To be deprecated; only valid for Android framework.
|
| 774 | ##
|
| 775 |
|
| 776 | #Return true if Path has one owner. ##
|
| 777 |
|
| 778 | ##
|
| 779 |
|
| 780 | # ------------------------------------------------------------------------------
|
| 781 | #Subtopic Fill_Type |
| 782 | |
| 783 | #Enum FillType
|
| 784 |
|
| 785 | #Code
|
| 786 | enum FillType {
|
| 787 | kWinding_FillType
|
| 788 | kEvenOdd_FillType
|
| 789 | kInverseWinding_FillType
|
| 790 | kInverseEvenOdd_FillType
|
| 791 | };
|
| 792 | ##
|
| 793 | |
| 794 | Fill_Type selects the rule used to fill Path. Path set to kWinding_FillType |
| 795 | fills if the sum of Contour edges is not zero, where clockwise edges add one, and |
| 796 | counterclockwise edges subtract one. Path set to kEvenOdd_FillType fills if the |
| 797 | number of Contour edges is odd. Each Fill_Type has an inverse variant that |
| 798 | reverses the rule: |
| 799 | kInverseWinding_FillType fills where the sum of Contour edges is zero; |
| 800 | kInverseEvenOdd_FillType fills where the number of Contour edges is even. |
| 801 | |
| 802 | #Example |
| 803 | #Height 100 |
| 804 | #Description |
| 805 | The top row has two clockwise rectangles. The second row has one clockwise and |
| 806 | one counterclockwise rectangle. The even-odd variants draw the same. The |
| 807 | winding variants draw the top rectangle overlap, which has a winding of 2, the |
| 808 | same as the outer parts of the top rectangles, which have a winding of 1. |
| 809 | ## |
| 810 | void draw(SkCanvas* canvas) {
|
| 811 | SkPath path;
|
| 812 | path.addRect({10, 10, 30, 30}, SkPath::kCW_Direction);
|
| 813 | path.addRect({20, 20, 40, 40}, SkPath::kCW_Direction);
|
| 814 | path.addRect({10, 60, 30, 80}, SkPath::kCW_Direction);
|
| 815 | path.addRect({20, 70, 40, 90}, SkPath::kCCW_Direction);
|
| 816 | SkPaint strokePaint;
|
| 817 | strokePaint.setStyle(SkPaint::kStroke_Style);
|
| 818 | SkRect clipRect = {0, 0, 51, 100};
|
| 819 | canvas->drawPath(path, strokePaint);
|
| 820 | SkPaint fillPaint;
|
| 821 | for (auto fillType : { SkPath::kWinding_FillType, SkPath::kEvenOdd_FillType,
|
| 822 | SkPath::kInverseWinding_FillType, SkPath::kInverseEvenOdd_FillType } ) {
|
| 823 | canvas->translate(51, 0);
|
| 824 | canvas->save();
|
| 825 | canvas->clipRect(clipRect);
|
| 826 | path.setFillType(fillType);
|
| 827 | canvas->drawPath(path, fillPaint);
|
| 828 | canvas->restore();
|
| 829 | }
|
| 830 | } |
| 831 | ## |
| 832 |
|
| 833 | #Const kWinding_FillType
|
| 834 | Specifies fill as area is enclosed by a non-zero sum of Contour Directions.
|
| 835 | ##
|
| 836 | #Const kEvenOdd_FillType
|
| 837 | Specifies fill as area enclosed by an odd number of Contours.
|
| 838 | ##
|
| 839 | #Const kInverseWinding_FillType
|
| 840 | Specifies fill as area is enclosed by a zero sum of Contour Directions.
|
| 841 | ##
|
| 842 | #Const kInverseEvenOdd_FillType
|
| 843 | Specifies fill as area enclosed by an even number of Contours.
|
| 844 | ##
|
| 845 |
|
| 846 | #Example
|
| 847 | #Height 230
|
| 848 | void draw(SkCanvas* canvas) {
|
| 849 | SkPath path;
|
| 850 | path.addRect({20, 10, 80, 70}, SkPath::kCW_Direction);
|
| 851 | path.addRect({40, 30, 100, 90}, SkPath::kCW_Direction);
|
| 852 | SkPaint strokePaint;
|
| 853 | strokePaint.setStyle(SkPaint::kStroke_Style);
|
| 854 | SkRect clipRect = {0, 0, 128, 128};
|
| 855 | canvas->drawPath(path, strokePaint);
|
| 856 | canvas->drawLine({0, 50}, {120, 50}, strokePaint);
|
| 857 | SkPaint textPaint;
|
| 858 | textPaint.setAntiAlias(true);
|
| 859 | textPaint.setTextAlign(SkPaint::kCenter_Align);
|
| 860 | SkScalar textHPos[] = { 10, 30, 60, 90, 110 };
|
| 861 | canvas->drawPosTextH("01210", 5, textHPos, 48, textPaint);
|
| 862 | textPaint.setTextSize(18);
|
| 863 | canvas->translate(0, 128);
|
| 864 | canvas->scale(.5f, .5f);
|
| 865 | canvas->drawString("inverse", 384, 150, textPaint);
|
| 866 | SkPaint fillPaint;
|
| 867 | for (auto fillType : { SkPath::kWinding_FillType, SkPath::kEvenOdd_FillType,
|
| 868 | SkPath::kInverseWinding_FillType, SkPath::kInverseEvenOdd_FillType } ) {
|
| 869 | canvas->save();
|
| 870 | canvas->clipRect(clipRect);
|
| 871 | path.setFillType(fillType);
|
| 872 | canvas->drawPath(path, fillPaint);
|
| 873 | canvas->restore();
|
| 874 | canvas->drawString(fillType & 1 ? "even-odd" : "winding", 64, 170, textPaint);
|
| 875 | canvas->translate(128, 0);
|
| 876 | }
|
| 877 | }
|
| 878 | ##
|
| 879 |
|
| 880 | #SeeAlso SkPaint::Style Direction getFillType setFillType
|
| 881 |
|
| 882 | ##
|
| 883 |
|
| 884 | # ------------------------------------------------------------------------------
|
| 885 |
|
| 886 | #Method FillType getFillType() const
|
| 887 |
|
| 888 | Returns FillType, the rule used to fill Path. FillType of a new Path is
|
| 889 | kWinding_FillType.
|
| 890 |
|
| 891 | #Return one of: kWinding_FillType, kEvenOdd_FillType, kInverseWinding_FillType,
|
| 892 | kInverseEvenOdd_FillType.
|
| 893 | ##
|
| 894 |
|
| 895 | #Example
|
| 896 | SkPath path;
|
| 897 | SkDebugf("default path fill type is %s\n",
|
| 898 | path.getFillType() == SkPath::kWinding_FillType ? "kWinding_FillType" :
|
| 899 | path.getFillType() == SkPath::kEvenOdd_FillType ? "kEvenOdd_FillType" :
|
| 900 | path.getFillType() == SkPath::kInverseWinding_FillType ? "kInverseWinding_FillType" :
|
| 901 | "kInverseEvenOdd_FillType");
|
| 902 | #StdOut
|
| 903 | default path fill type is kWinding_FillType
|
| 904 | ##
|
| 905 | ##
|
| 906 |
|
| 907 | #SeeAlso FillType setFillType isInverseFillType
|
| 908 |
|
| 909 | ##
|
| 910 |
|
| 911 | # ------------------------------------------------------------------------------
|
| 912 |
|
| 913 | #Method void setFillType(FillType ft)
|
| 914 |
|
| 915 | Sets FillType, the rule used to fill Path. While setFillType does not check
|
| 916 | that ft is legal, values outside of FillType are not supported.
|
| 917 |
|
| 918 | #Param ft one of: kWinding_FillType, kEvenOdd_FillType, kInverseWinding_FillType,
|
| 919 | kInverseEvenOdd_FillType.
|
| 920 | ##
|
| 921 |
|
| 922 | #Example
|
| 923 | #Description
|
| 924 | If empty Path is set to inverse FillType, it fills all pixels.
|
| 925 | ##
|
| 926 | #Height 64
|
| 927 | SkPath path;
|
| 928 | path.setFillType(SkPath::kInverseWinding_FillType);
|
| 929 | SkPaint paint;
|
| 930 | paint.setColor(SK_ColorBLUE);
|
| 931 | canvas->drawPath(path, paint);
|
| 932 | ##
|
| 933 |
|
| 934 | #SeeAlso FillType getFillType toggleInverseFillType
|
| 935 |
|
| 936 | ##
|
| 937 |
|
| 938 | # ------------------------------------------------------------------------------
|
| 939 |
|
| 940 | #Method bool isInverseFillType() const
|
| 941 |
|
| 942 | Returns if FillType describes area outside Path geometry. The inverse fill area
|
| 943 | extends indefinitely.
|
| 944 |
|
| 945 | #Return true if FillType is kInverseWinding_FillType or kInverseEvenOdd_FillType. ##
|
| 946 |
|
| 947 | #Example
|
| 948 | SkPath path;
|
| 949 | SkDebugf("default path fill type is inverse: %s\n",
|
| 950 | path.isInverseFillType() ? "true" : "false");
|
| 951 | #StdOut
|
| 952 | default path fill type is inverse: false
|
| 953 | ##
|
| 954 | ##
|
| 955 |
|
| 956 | #SeeAlso FillType getFillType setFillType toggleInverseFillType
|
| 957 |
|
| 958 | ##
|
| 959 |
|
| 960 | # ------------------------------------------------------------------------------
|
| 961 |
|
| 962 | #Method void toggleInverseFillType()
|
| 963 |
|
| 964 | Replace FillType with its inverse. The inverse of FillType describes the area
|
| 965 | unmodified by the original FillType.
|
| 966 |
|
| 967 | #Table
|
| 968 | #Legend
|
| 969 | # FillType # toggled FillType ##
|
| 970 | ##
|
| 971 | # kWinding_FillType # kInverseWinding_FillType ##
|
| 972 | # kEvenOdd_FillType # kInverseEvenOdd_FillType ##
|
| 973 | # kInverseWinding_FillType # kWinding_FillType ##
|
| 974 | # kInverseEvenOdd_FillType # kEvenOdd_FillType ##
|
| 975 | ##
|
| 976 |
|
| 977 | #Example
|
| 978 | #Description
|
| 979 | Path drawn normally and through its inverse touches every pixel once.
|
| 980 | ##
|
| 981 | #Height 100
|
| 982 | SkPath path;
|
| 983 | SkPaint paint;
|
| 984 | paint.setColor(SK_ColorRED);
|
| 985 | paint.setTextSize(80); |
| 986 | paint.getTextPath("ABC", 3, 20, 80, &path); |
| 987 | canvas->drawPath(path, paint);
|
| 988 | path.toggleInverseFillType();
|
| 989 | paint.setColor(SK_ColorGREEN);
|
| 990 | canvas->drawPath(path, paint);
|
| 991 | ##
|
| 992 |
|
| 993 | #SeeAlso FillType getFillType setFillType isInverseFillType
|
| 994 |
|
| 995 | ##
|
| 996 |
|
| 997 | #Subtopic Fill_Type ## |
| 998 |
|
| 999 | # ------------------------------------------------------------------------------
|
| 1000 | |
| 1001 | #Subtopic Convexity |
| 1002 |
|
| 1003 | #Enum Convexity
|
| 1004 |
|
| 1005 | #Code
|
| 1006 | enum Convexity {
|
| 1007 | kUnknown_Convexity,
|
| 1008 | kConvex_Convexity,
|
| 1009 | kConcave_Convexity
|
| 1010 | };
|
| 1011 | ##
|
| 1012 |
|
| 1013 | Path is convex if it contains one Contour and Contour loops no more than |
| 1014 | 360 degrees, and Contour angles all have same Direction. Convex Path |
| 1015 | may have better performance and require fewer resources on GPU_Surface. |
| 1016 | |
| 1017 | Path is concave when either at least one Direction change is clockwise and
|
| 1018 | another is counterclockwise, or the sum of the changes in Direction is not 360
|
| 1019 | degrees.
|
| 1020 |
|
| 1021 | Initially Path Convexity is kUnknown_Convexity. Path Convexity is computed
|
| 1022 | if needed by destination Surface.
|
| 1023 |
|
| 1024 | #Const kUnknown_Convexity
|
| 1025 | Indicates Convexity has not been determined.
|
| 1026 | ##
|
| 1027 | #Const kConvex_Convexity
|
| 1028 | Path has one Contour made of a simple geometry without indentations.
|
| 1029 | ##
|
| 1030 | #Const kConcave_Convexity
|
| 1031 | Path has more than one Contour, or a geometry with indentations.
|
| 1032 | ##
|
| 1033 |
|
| 1034 | #Example
|
| 1035 | void draw(SkCanvas* canvas) {
|
| 1036 | SkPaint paint;
|
| 1037 | SkPoint quad[] = {{70, 70}, {20, 20}, {120, 20}, {120, 120}};
|
| 1038 | const char* labels[] = { "unknown", "convex", "concave" };
|
| 1039 | for (SkScalar x : { 40, 100 } ) {
|
| 1040 | SkPath path;
|
| 1041 | quad[0].fX = x;
|
| 1042 | path.addPoly(quad, SK_ARRAY_COUNT(quad), true);
|
| 1043 | canvas->drawPath(path, paint);
|
| 1044 | canvas->drawString(labels[(int) path.getConvexity()], 30, 100, paint);
|
| 1045 | canvas->translate(100, 100);
|
| 1046 | }
|
| 1047 | }
|
| 1048 | ##
|
| 1049 |
|
| 1050 | #SeeAlso Contour Direction getConvexity getConvexityOrUnknown setConvexity isConvex
|
| 1051 |
|
| 1052 | #Enum Convexity ##
|
| 1053 |
|
| 1054 | #Method Convexity getConvexity() const
|
| 1055 |
|
| 1056 | Computes Convexity if required, and returns stored value.
|
| 1057 | Convexity is computed if stored value is kUnknown_Convexity,
|
| 1058 | or if Path has been altered since Convexity was computed or set.
|
| 1059 |
|
| 1060 | #Return Computed or stored Convexity. ##
|
| 1061 |
|
| 1062 | #Example
|
| 1063 | void draw(SkCanvas* canvas) {
|
| 1064 | auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
| 1065 | SkDebugf("%s path convexity is %s\n", prefix,
|
| 1066 | SkPath::kUnknown_Convexity == path.getConvexity() ? "unknown" :
|
| 1067 | SkPath::kConvex_Convexity == path.getConvexity() ? "convex" : "concave"); };
|
| 1068 | SkPath path;
|
| 1069 | debugster("initial", path);
|
| 1070 | path.lineTo(50, 0);
|
| 1071 | debugster("first line", path);
|
| 1072 | path.lineTo(50, 50);
|
| 1073 | debugster("second line", path);
|
| 1074 | path.lineTo(100, 50);
|
| 1075 | debugster("third line", path);
|
| 1076 | }
|
| 1077 | ##
|
| 1078 |
|
| 1079 | #SeeAlso Convexity Contour Direction getConvexityOrUnknown setConvexity isConvex
|
| 1080 |
|
| 1081 | ##
|
| 1082 |
|
| 1083 | # ------------------------------------------------------------------------------
|
| 1084 |
|
| 1085 | #Method Convexity getConvexityOrUnknown() const
|
| 1086 |
|
| 1087 | Returns last computed Convexity, or kUnknown_Convexity if
|
| 1088 | Path has been altered since Convexity was computed or set.
|
| 1089 |
|
| 1090 | #Return Stored Convexity. ##
|
| 1091 |
|
| 1092 | #Example
|
| 1093 | #Description
|
| 1094 | Convexity is unknown unless getConvexity is called without a subsequent call
|
| 1095 | that alters the path.
|
| 1096 | ##
|
| 1097 | void draw(SkCanvas* canvas) {
|
| 1098 | auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
| 1099 | SkDebugf("%s path convexity is %s\n", prefix,
|
| 1100 | SkPath::kUnknown_Convexity == path.getConvexityOrUnknown() ? "unknown" :
|
| 1101 | SkPath::kConvex_Convexity == path.getConvexityOrUnknown() ? "convex" : "concave"); };
|
| 1102 | SkPath path;
|
| 1103 | debugster("initial", path);
|
| 1104 | path.lineTo(50, 0);
|
| 1105 | debugster("first line", path);
|
| 1106 | path.getConvexity();
|
| 1107 | path.lineTo(50, 50);
|
| 1108 | debugster("second line", path);
|
| 1109 | path.lineTo(100, 50);
|
| 1110 | path.getConvexity();
|
| 1111 | debugster("third line", path);
|
| 1112 | }
|
| 1113 | ##
|
| 1114 |
|
| 1115 | #SeeAlso Convexity Contour Direction getConvexity setConvexity isConvex
|
| 1116 |
|
| 1117 | ##
|
| 1118 |
|
| 1119 | # ------------------------------------------------------------------------------
|
| 1120 |
|
| 1121 | #Method void setConvexity(Convexity convexity)
|
| 1122 |
|
| 1123 | Stores convexity so that it is later returned by getConvexity or getConvexityOrUnknown.
|
| 1124 | convexity may differ from getConvexity, although setting an incorrect value may
|
| 1125 | cause incorrect or inefficient drawing.
|
| 1126 |
|
| 1127 | If convexity is kUnknown_Convexity: getConvexity will
|
| 1128 | compute Convexity, and getConvexityOrUnknown will return kUnknown_Convexity.
|
| 1129 |
|
| 1130 | If convexity is kConvex_Convexity or kConcave_Convexity, getConvexity
|
| 1131 | and getConvexityOrUnknown will return convexity until the path is
|
| 1132 | altered.
|
| 1133 |
|
| 1134 | #Param convexity One of kUnknown_Convexity, kConvex_Convexity, or kConcave_Convexity. ##
|
| 1135 |
|
| 1136 | #Example
|
| 1137 | void draw(SkCanvas* canvas) {
|
| 1138 | auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
| 1139 | SkDebugf("%s path convexity is %s\n", prefix,
|
| 1140 | SkPath::kUnknown_Convexity == path.getConvexity() ? "unknown" :
|
| 1141 | SkPath::kConvex_Convexity == path.getConvexity() ? "convex" : "concave"); };
|
| 1142 | SkPoint quad[] = {{70, 70}, {20, 20}, {120, 20}, {120, 120}};
|
| 1143 | SkPath path;
|
| 1144 | path.addPoly(quad, SK_ARRAY_COUNT(quad), true);
|
| 1145 | debugster("initial", path);
|
| 1146 | path.setConvexity(SkPath::kConcave_Convexity);
|
| 1147 | debugster("after forcing concave", path);
|
| 1148 | path.setConvexity(SkPath::kUnknown_Convexity);
|
| 1149 | debugster("after forcing unknown", path);
|
| 1150 | }
|
| 1151 | ##
|
| 1152 |
|
| 1153 | #SeeAlso Convexity Contour Direction getConvexity getConvexityOrUnknown isConvex
|
| 1154 |
|
| 1155 | ##
|
| 1156 |
|
| 1157 | # ------------------------------------------------------------------------------
|
| 1158 |
|
| 1159 | #Method bool isConvex() const
|
| 1160 |
|
| 1161 | Computes Convexity if required, and returns true if value is kConvex_Convexity.
|
| 1162 | If setConvexity was called with kConvex_Convexity or kConcave_Convexity, and
|
| 1163 | the path has not been altered, Convexity is not recomputed.
|
| 1164 |
|
| 1165 | #Return true if Convexity stored or computed is kConvex_Convexity. ##
|
| 1166 |
|
| 1167 | #Example
|
| 1168 | #Description
|
| 1169 | Concave shape is erroneously considered convex after a forced call to
|
| 1170 | setConvexity.
|
| 1171 | ##
|
| 1172 | void draw(SkCanvas* canvas) {
|
| 1173 | SkPaint paint;
|
| 1174 | SkPoint quad[] = {{70, 70}, {20, 20}, {120, 20}, {120, 120}};
|
| 1175 | for (SkScalar x : { 40, 100 } ) {
|
| 1176 | SkPath path;
|
| 1177 | quad[0].fX = x;
|
| 1178 | path.addPoly(quad, SK_ARRAY_COUNT(quad), true);
|
| 1179 | path.setConvexity(SkPath::kConvex_Convexity);
|
| 1180 | canvas->drawPath(path, paint);
|
| 1181 | canvas->drawString(path.isConvex() ? "convex" : "not convex", 30, 100, paint);
|
| 1182 | canvas->translate(100, 100);
|
| 1183 | }
|
| 1184 | }
|
| 1185 | ##
|
| 1186 |
|
| 1187 | #SeeAlso Convexity Contour Direction getConvexity getConvexityOrUnknown setConvexity
|
| 1188 |
|
| 1189 | ##
|
| 1190 |
|
| 1191 | # ------------------------------------------------------------------------------
|
| 1192 |
|
| 1193 | #Method void setIsConvex(bool isConvex)
|
| 1194 |
|
| 1195 | #Deprecated
|
| 1196 | Use setConvexity.
|
| 1197 | ##
|
| 1198 |
|
| 1199 | ##
|
| 1200 |
|
| 1201 | #Subtopic Convexity ##
|
| 1202 |
|
| 1203 | # ------------------------------------------------------------------------------
|
| 1204 |
|
| 1205 | #Method bool isOval(SkRect* rect, Direction* dir = nullptr,
|
| 1206 | unsigned* start = nullptr) const
|
| 1207 |
|
| 1208 | Path is Oval if constructed by addCircle, addOval; and in some cases,
|
| 1209 | addRoundRect, addRRect. Path constructed with conicTo or rConicTo will not
|
| 1210 | return true though Path draws Oval.
|
| 1211 |
|
| 1212 | isOval triggers performance optimizations on some GPU_Surface implementations.
|
| 1213 |
|
| 1214 | #Param rect storage for bounding Rect of Oval. Oval is Circle if rect width
|
| 1215 | equals rect height. Unwritten if Path is not Oval. May be nullptr.
|
| 1216 | ##
|
| 1217 | #Param dir storage for Direction; kCW_Direction if clockwise, kCCW_Direction if
|
| 1218 | counterclockwise. Unwritten if Path is not Oval. May be nullptr.
|
| 1219 | ##
|
| 1220 | #Param start storage for start of Oval: 0 for top,
|
| 1221 | 1 for right, 2 for bottom, 3 for left. Unwritten if Path is not Oval. May be nullptr.
|
| 1222 | ##
|
| 1223 |
|
| 1224 | #Return true if Path was constructed by method that reduces to Oval. ##
|
| 1225 |
|
| 1226 | #Example
|
| 1227 | void draw(SkCanvas* canvas) {
|
| 1228 | SkPaint paint;
|
| 1229 | SkPath path;
|
| 1230 | path.addOval({20, 20, 220, 220}, SkPath::kCW_Direction, 1);
|
| 1231 | SkRect bounds;
|
| 1232 | SkPath::Direction direction;
|
| 1233 | unsigned start;
|
| 1234 | path.isOval(&bounds, &direction, &start);
|
| 1235 | paint.setColor(0xFF9FBFFF);
|
| 1236 | canvas->drawRect(bounds, paint);
|
| 1237 | paint.setColor(0x3f000000);
|
| 1238 | canvas->drawPath(path, paint);
|
| 1239 | paint.setColor(SK_ColorBLACK);
|
| 1240 | canvas->rotate(start * 90, bounds.centerX(), bounds.centerY());
|
| 1241 | char startText = '0' + start;
|
| 1242 | paint.setTextSize(20);
|
| 1243 | canvas->drawText(&startText, 1, bounds.centerX(), bounds.fTop + 20, paint);
|
| 1244 | paint.setStyle(SkPaint::kStroke_Style);
|
| 1245 | paint.setStrokeWidth(4);
|
| 1246 | path.reset();
|
| 1247 | path.addArc(bounds, -90, SkPath::kCW_Direction == direction ? 90 : -90);
|
| 1248 | path.rLineTo(20, -20);
|
| 1249 | canvas->drawPath(path, paint);
|
| 1250 | }
|
| 1251 | ##
|
| 1252 |
|
| 1253 | #SeeAlso Oval addCircle addOval
|
| 1254 |
|
| 1255 | ##
|
| 1256 |
|
| 1257 | # ------------------------------------------------------------------------------
|
| 1258 |
|
| 1259 | #Method bool isRRect(SkRRect* rrect, Direction* dir = nullptr,
|
| 1260 | unsigned* start = nullptr) const
|
| 1261 |
|
| 1262 | Path is Round_Rect if constructed by addRoundRect, addRRect; and if construction
|
| 1263 | is not empty, not Rect, and not Oval. Path constructed with other other calls
|
| 1264 | will not return true though Path draws Round_Rect.
|
| 1265 |
|
| 1266 | isRRect triggers performance optimizations on some GPU_Surface implementations.
|
| 1267 |
|
| 1268 | #Param rrect storage for bounding Rect of Round_Rect.
|
| 1269 | Unwritten if Path is not Round_Rect. May be nullptr.
|
| 1270 | ##
|
| 1271 | #Param dir storage for Direction; kCW_Direction if clockwise, kCCW_Direction if
|
| 1272 | counterclockwise. Unwritten if Path is not Round_Rect. May be nullptr.
|
| 1273 | ##
|
| 1274 | #Param start storage for start of Round_Rect: 0 for top,
|
| 1275 | 1 for right, 2 for bottom, 3 for left. Unwritten if Path is not Round_Rect. May be nullptr.
|
| 1276 | ##
|
| 1277 |
|
| 1278 | #Return true for Round_Rect Path constructed by addRoundRect or addRRect. ##
|
| 1279 |
|
| 1280 | #Example
|
| 1281 | void draw(SkCanvas* canvas) {
|
| 1282 | SkPaint paint;
|
| 1283 | SkPath path;
|
| 1284 | path.addRRect(SkRRect::MakeRectXY({20, 20, 220, 220}, 30, 50), SkPath::kCCW_Direction, 3);
|
| 1285 | SkRRect rrect;
|
| 1286 | SkPath::Direction direction;
|
| 1287 | unsigned start;
|
| 1288 | path.isRRect(&rrect, &direction, &start);
|
| 1289 | const SkRect& bounds = rrect.rect();
|
| 1290 | paint.setColor(0xFF9FBFFF);
|
| 1291 | canvas->drawRect(bounds, paint);
|
| 1292 | paint.setColor(0x3f000000);
|
| 1293 | canvas->drawPath(path, paint);
|
| 1294 | paint.setColor(SK_ColorBLACK);
|
| 1295 | canvas->rotate(start * 90, bounds.centerX(), bounds.centerY());
|
| 1296 | char startText = '0' + start;
|
| 1297 | paint.setTextSize(20);
|
| 1298 | canvas->drawText(&startText, 1, bounds.centerX(), bounds.fTop + 20, paint);
|
| 1299 | paint.setStyle(SkPaint::kStroke_Style);
|
| 1300 | paint.setStrokeWidth(4);
|
| 1301 | path.reset();
|
| 1302 | path.addArc(bounds, -90, SkPath::kCW_Direction == direction ? 90 : -90);
|
| 1303 | path.rLineTo(20, -20);
|
| 1304 | canvas->drawPath(path, paint);
|
| 1305 | }
|
| 1306 | ##
|
| 1307 |
|
| 1308 | #SeeAlso Round_Rect addRoundRect addRRect
|
| 1309 |
|
| 1310 | ##
|
| 1311 |
|
| 1312 | # ------------------------------------------------------------------------------
|
| 1313 |
|
| 1314 | #Method void reset()
|
| 1315 |
|
| 1316 | Sets Path to its intial state.
|
| 1317 | Removes Verb_Array, Point_Array, and Weights, and sets FillType to kWinding_FillType.
|
| 1318 | Internal storage associated with Path is released.
|
| 1319 |
|
| 1320 | #Example
|
| 1321 | SkPath path1, path2;
|
| 1322 | path1.setFillType(SkPath::kInverseWinding_FillType);
|
| 1323 | path1.addRect({10, 20, 30, 40});
|
| 1324 | SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!');
|
| 1325 | path1.reset();
|
| 1326 | SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!');
|
| 1327 | ##
|
| 1328 |
|
| 1329 | #SeeAlso rewind()
|
| 1330 |
|
| 1331 | ##
|
| 1332 |
|
| 1333 | # ------------------------------------------------------------------------------
|
| 1334 |
|
| 1335 | #Method void rewind()
|
| 1336 |
|
| 1337 | Sets Path to its intial state, preserving internal storage.
|
| 1338 | Removes Verb_Array, Point_Array, and Weights, and sets FillType to kWinding_FillType.
|
| 1339 | Internal storage associated with Path is retained.
|
| 1340 |
|
| 1341 | Use rewind() instead of reset() if Path storage will be reused and performance
|
| 1342 | is critical.
|
| 1343 |
|
| 1344 | #Example
|
| 1345 | #Description
|
| 1346 | Although path1 retains its internal storage, it is indistinguishable from
|
| 1347 | a newly initialized path.
|
| 1348 | ##
|
| 1349 | SkPath path1, path2;
|
| 1350 | path1.setFillType(SkPath::kInverseWinding_FillType);
|
| 1351 | path1.addRect({10, 20, 30, 40});
|
| 1352 | SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!');
|
| 1353 | path1.rewind();
|
| 1354 | SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!');
|
| 1355 | ##
|
| 1356 |
|
| 1357 | #SeeAlso reset()
|
| 1358 |
|
| 1359 | ##
|
| 1360 |
|
| 1361 | # ------------------------------------------------------------------------------
|
| 1362 |
|
| 1363 | #Method bool isEmpty() const
|
| 1364 |
|
| 1365 | Empty Path may have FillType but has no SkPoint, Verb, or Conic_Weight.
|
| 1366 | SkPath() constructs empty Path; reset() and (rewind) make Path empty.
|
| 1367 |
|
| 1368 | #Return true if the path contains no Verb array. ##
|
| 1369 |
|
| 1370 | #Example
|
| 1371 | void draw(SkCanvas* canvas) {
|
| 1372 | auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
| 1373 | SkDebugf("%s path is %s" "empty\n", prefix, path.isEmpty() ? "" : "not ");
|
| 1374 | };
|
| 1375 | SkPath path;
|
| 1376 | debugster("initial", path);
|
| 1377 | path.moveTo(0, 0);
|
| 1378 | debugster("after moveTo", path);
|
| 1379 | path.rewind();
|
| 1380 | debugster("after rewind", path);
|
| 1381 | path.lineTo(0, 0);
|
| 1382 | debugster("after lineTo", path);
|
| 1383 | path.reset();
|
| 1384 | debugster("after reset", path);
|
| 1385 | }
|
| 1386 | #StdOut
|
| 1387 | initial path is empty
|
| 1388 | after moveTo path is not empty
|
| 1389 | after rewind path is empty
|
| 1390 | after lineTo path is not empty
|
| 1391 | after reset path is empty
|
| 1392 | ##
|
| 1393 | ##
|
| 1394 |
|
| 1395 | #SeeAlso SkPath() reset() rewind()
|
| 1396 |
|
| 1397 | ##
|
| 1398 |
|
| 1399 | # ------------------------------------------------------------------------------
|
| 1400 |
|
| 1401 | #Method bool isLastContourClosed() const
|
| 1402 |
|
| 1403 | Contour is closed if Path Verb array was last modified by close(). When stroked,
|
| 1404 | closed Contour draws Paint_Stroke_Join instead of Paint_Stroke_Cap at first and last Point.
|
| 1405 |
|
| 1406 | #Return true if the last Contour ends with a kClose_Verb. ##
|
| 1407 |
|
| 1408 | #Example
|
| 1409 | #Description
|
| 1410 | close() has no effect if Path is empty; isLastContourClosed() returns
|
| 1411 | false until Path has geometry followed by close().
|
| 1412 | ##
|
| 1413 | void draw(SkCanvas* canvas) {
|
| 1414 | auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
| 1415 | SkDebugf("%s last contour is %s" "closed\n", prefix,
|
| 1416 | path.isLastContourClosed() ? "" : "not ");
|
| 1417 | };
|
| 1418 | SkPath path;
|
| 1419 | debugster("initial", path);
|
| 1420 | path.close();
|
| 1421 | debugster("after close", path);
|
| 1422 | path.lineTo(0, 0);
|
| 1423 | debugster("after lineTo", path);
|
| 1424 | path.close();
|
| 1425 | debugster("after close", path);
|
| 1426 | }
|
| 1427 | #StdOut
|
| 1428 | initial last contour is not closed
|
| 1429 | after close last contour is not closed
|
| 1430 | after lineTo last contour is not closed
|
| 1431 | after close last contour is closed
|
| 1432 | ##
|
| 1433 | ##
|
| 1434 |
|
| 1435 | #SeeAlso close()
|
| 1436 |
|
| 1437 | ##
|
| 1438 |
|
| 1439 | # ------------------------------------------------------------------------------
|
| 1440 |
|
| 1441 | #Method bool isFinite() const
|
| 1442 |
|
| 1443 | Finite Point array values are between negative SK_ScalarMax and
|
| 1444 | positive SK_ScalarMax. Any Point array value of
|
| 1445 | SK_ScalarInfinity, SK_ScalarNegativeInfinity, or SK_ScalarNaN
|
| 1446 | cause isFinite to return false.
|
| 1447 |
|
| 1448 | #Return true if all Point values are finite. ##
|
| 1449 |
|
| 1450 | #Example
|
| 1451 | void draw(SkCanvas* canvas) {
|
| 1452 | auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
| 1453 | SkDebugf("%s path is %s" "finite\n", prefix, path.isFinite() ? "" : "not ");
|
| 1454 | };
|
| 1455 | SkPath path;
|
| 1456 | debugster("initial", path);
|
| 1457 | path.lineTo(SK_ScalarMax, SK_ScalarMax);
|
| 1458 | debugster("after line", path);
|
| 1459 | SkMatrix matrix;
|
| 1460 | matrix.setScale(2, 2);
|
| 1461 | path.transform(matrix);
|
| 1462 | debugster("after scale", path);
|
| 1463 | }
|
| 1464 | #StdOut
|
| 1465 | initial path is finite
|
| 1466 | after line path is finite
|
| 1467 | after scale path is not finite
|
| 1468 | ##
|
| 1469 | ##
|
| 1470 |
|
| 1471 | #SeeAlso SkScalar
|
| 1472 | ##
|
| 1473 |
|
| 1474 | # ------------------------------------------------------------------------------
|
| 1475 |
|
| 1476 | #Method bool isVolatile() const
|
| 1477 |
|
| 1478 | Returns true if the path is volatile; it will not be altered or discarded
|
| 1479 | by the caller after it is drawn. Paths by default have volatile set false, allowing
|
| 1480 | Surface to attach a cache of data which speeds repeated drawing. If true, Surface
|
| 1481 | may not speed repeated drawing.
|
| 1482 |
|
| 1483 | #Return true if caller will alter Path after drawing. ##
|
| 1484 |
|
| 1485 | #Example
|
| 1486 | SkPath path;
|
| 1487 | SkDebugf("volatile by default is %s\n", path.isVolatile() ? "true" : "false");
|
| 1488 | #StdOut
|
| 1489 | volatile by default is false
|
| 1490 | ##
|
| 1491 | ##
|
| 1492 |
|
| 1493 | #SeeAlso setIsVolatile
|
| 1494 |
|
| 1495 | ##
|
| 1496 |
|
| 1497 | # ------------------------------------------------------------------------------
|
| 1498 |
|
| 1499 | #Method void setIsVolatile(bool isVolatile)
|
| 1500 |
|
| 1501 | Specify whether Path is volatile; whether it will be altered or discarded
|
| 1502 | by the caller after it is drawn. Paths by default have volatile set false, allowing
|
| 1503 | Device to attach a cache of data which speeds repeated drawing.
|
| 1504 |
|
| 1505 | Mark temporary paths, discarded or modified after use, as volatile
|
| 1506 | to inform Device that the path need not be cached.
|
| 1507 |
|
| 1508 | Mark animating Path volatile to improve performance.
|
| 1509 | Mark unchanging Path non-volative to improve repeated rendering.
|
| 1510 |
|
| 1511 | Raster_Surface Path draws are affected by volatile for some shadows.
|
| 1512 | GPU_Surface Path draws are affected by volatile for some shadows and concave geometries.
|
| 1513 |
|
| 1514 | #Param isVolatile true if caller will alter Path after drawing. ##
|
| 1515 |
|
| 1516 | #Example
|
| 1517 | #Height 50
|
| 1518 | #Width 50
|
| 1519 | SkPaint paint;
|
| 1520 | paint.setStyle(SkPaint::kStroke_Style);
|
| 1521 | SkPath path;
|
| 1522 | path.setIsVolatile(true);
|
| 1523 | path.lineTo(40, 40);
|
| 1524 | canvas->drawPath(path, paint);
|
| 1525 | path.rewind();
|
| 1526 | path.moveTo(0, 40);
|
| 1527 | path.lineTo(40, 0);
|
| 1528 | canvas->drawPath(path, paint);
|
| 1529 | ##
|
| 1530 |
|
| 1531 | #ToDo tie example to bench to show how volatile affects speed or dm to show resource usage ##
|
| 1532 |
|
| 1533 | #SeeAlso isVolatile
|
| 1534 |
|
| 1535 | ##
|
| 1536 |
|
| 1537 | # ------------------------------------------------------------------------------
|
| 1538 |
|
| 1539 | #Method static bool IsLineDegenerate(const SkPoint& p1, const SkPoint& p2, bool exact)
|
| 1540 |
|
| 1541 | Test if Line between Point pair is degenerate.
|
| 1542 | Line with no length or that moves a very short distance is degenerate; it is
|
| 1543 | treated as a point.
|
| 1544 |
|
| 1545 | #Param p1 Line start point. ##
|
| 1546 | #Param p2 Line end point. ##
|
| 1547 | #Param exact If true, returns true only if p1 equals p2. If false, returns true
|
| 1548 | if p1 equals or nearly equals p2.
|
| 1549 | ##
|
| 1550 |
|
| 1551 | #Return true if Line is degenerate; its length is effectively zero. ##
|
| 1552 |
|
| 1553 | #Example
|
| 1554 | #Description
|
| 1555 | As single precision floats, 100 and 100.000001f have the same bit representation,
|
| 1556 | and are exactly equal. 100 and 100.0001f have different bit representations, and
|
| 1557 | are not exactly equal, but are nearly equal.
|
| 1558 | ##
|
| 1559 | void draw(SkCanvas* canvas) {
|
| 1560 | SkPoint points[] = { {100, 100}, {100.000001f, 100.000001f}, {100.0001f, 100.0001f} };
|
| 1561 | for (size_t i = 0; i < SK_ARRAY_COUNT(points) - 1; ++i) {
|
| 1562 | for (bool exact : { false, true } ) {
|
| 1563 | SkDebugf("line from (%1.8g,%1.8g) to (%1.8g,%1.8g) is %s" "degenerate, %s\n",
|
| 1564 | points[i].fX, points[i].fY, points[i + 1].fX, points[i + 1].fY,
|
| 1565 | SkPath::IsLineDegenerate(points[i], points[i + 1], exact)
|
| 1566 | ? "" : "not ", exact ? "exactly" : "nearly");
|
| 1567 | }
|
| 1568 | }
|
| 1569 | }
|
| 1570 | #StdOut
|
| 1571 | line from (100,100) to (100,100) is degenerate, nearly
|
| 1572 | line from (100,100) to (100,100) is degenerate, exactly
|
| 1573 | line from (100,100) to (100.0001,100.0001) is degenerate, nearly
|
| 1574 | line from (100,100) to (100.0001,100.0001) is not degenerate, exactly
|
| 1575 | #StdOut ##
|
| 1576 | ##
|
| 1577 |
|
| 1578 | #SeeAlso IsQuadDegenerate IsCubicDegenerate SkPoint::equalsWithinTolerance
|
| 1579 | ##
|
| 1580 |
|
| 1581 | # ------------------------------------------------------------------------------
|
| 1582 |
|
| 1583 | #Method static bool IsQuadDegenerate(const SkPoint& p1, const SkPoint& p2,
|
| 1584 | const SkPoint& p3, bool exact)
|
| 1585 |
|
| 1586 | Test if Quad is degenerate.
|
| 1587 | Quad with no length or that moves a very short distance is degenerate; it is
|
| 1588 | treated as a point.
|
| 1589 |
|
| 1590 | #Param p1 Quad start point. ##
|
| 1591 | #Param p2 Quad control point. ##
|
| 1592 | #Param p3 Quad end point. ##
|
| 1593 | #Param exact If true, returns true only if p1, p2, and p3 are equal.
|
| 1594 | If false, returns true if p1, p2, and p3 are equal or nearly equal.
|
| 1595 | ##
|
| 1596 |
|
| 1597 | #Return true if Quad is degenerate; its length is effectively zero. ##
|
| 1598 |
|
| 1599 | #Example
|
| 1600 | #Description
|
| 1601 | As single precision floats: 100, 100.00001f, and 100.00002f have different bit representations
|
| 1602 | but nearly the same value. Translating all three by 1000 gives them the same bit representation;
|
| 1603 | the fractional portion of the number can't be represented by the float and is lost.
|
| 1604 | ##
|
| 1605 | void draw(SkCanvas* canvas) {
|
| 1606 | auto debugster = [](const SkPath& path, bool exact) -> void {
|
| 1607 | SkDebugf("quad (%1.8g,%1.8g), (%1.8g,%1.8g), (%1.8g,%1.8g) is %s" "degenerate, %s\n",
|
| 1608 | path.getPoint(0).fX, path.getPoint(0).fY, path.getPoint(1).fX,
|
| 1609 | path.getPoint(1).fY, path.getPoint(2).fX, path.getPoint(2).fY,
|
| 1610 | SkPath::IsQuadDegenerate(path.getPoint(0), path.getPoint(1), path.getPoint(2), exact) ?
|
| 1611 | "" : "not ", exact ? "exactly" : "nearly");
|
| 1612 | };
|
| 1613 | SkPath path, offset;
|
| 1614 | path.moveTo({100, 100});
|
| 1615 | path.quadTo({100.00001f, 100.00001f}, {100.00002f, 100.00002f});
|
| 1616 | offset.addPath(path, 1000, 1000);
|
| 1617 | for (bool exact : { false, true } ) {
|
| 1618 | debugster(path, exact);
|
| 1619 | debugster(offset, exact);
|
| 1620 | }
|
| 1621 | }
|
| 1622 | #StdOut
|
| 1623 | quad (100,100), (100.00001,100.00001), (100.00002,100.00002) is degenerate, nearly
|
| 1624 | quad (1100,1100), (1100,1100), (1100,1100) is degenerate, nearly
|
| 1625 | quad (100,100), (100.00001,100.00001), (100.00002,100.00002) is not degenerate, exactly
|
| 1626 | quad (1100,1100), (1100,1100), (1100,1100) is degenerate, exactly
|
| 1627 | #StdOut ##
|
| 1628 | ##
|
| 1629 |
|
| 1630 | #SeeAlso IsLineDegenerate IsCubicDegenerate SkPoint::equalsWithinTolerance
|
| 1631 | ##
|
| 1632 |
|
| 1633 | # ------------------------------------------------------------------------------
|
| 1634 |
|
| 1635 | #Method static bool IsCubicDegenerate(const SkPoint& p1, const SkPoint& p2,
|
| 1636 | const SkPoint& p3, const SkPoint& p4, bool exact)
|
| 1637 |
|
| 1638 | Test if Cubic is degenerate.
|
| 1639 | Cubic with no length or that moves a very short distance is degenerate; it is
|
| 1640 | treated as a point.
|
| 1641 |
|
| 1642 | #Param p1 Cubic start point. ##
|
| 1643 | #Param p2 Cubic control point 1. ##
|
| 1644 | #Param p3 Cubic control point 2. ##
|
| 1645 | #Param p4 Cubic end point. ##
|
| 1646 | #Param exact If true, returns true only if p1, p2, p3, and p4 are equal.
|
| 1647 | If false, returns true if p1, p2, p3, and p4 are equal or nearly equal.
|
| 1648 | ##
|
| 1649 |
|
| 1650 | #Return true if Cubic is degenerate; its length is effectively zero. ##
|
| 1651 |
|
| 1652 | #Example
|
| 1653 | void draw(SkCanvas* canvas) {
|
| 1654 | SkPoint points[] = {{1, 0}, {0, 0}, {0, 0}, {0, 0}};
|
| 1655 | SkScalar step = 1;
|
| 1656 | SkScalar prior, length, degenerate;
|
| 1657 | do {
|
| 1658 | prior = points[0].fX;
|
| 1659 | step /= 2;
|
| 1660 | if (SkPath::IsCubicDegenerate(points[0], points[1], points[2], points[3], false)) {
|
| 1661 | degenerate = prior;
|
| 1662 | points[0].fX += step;
|
| 1663 | } else {
|
| 1664 | length = prior;
|
| 1665 | points[0].fX -= step;
|
| 1666 | }
|
| 1667 | } while (prior != points[0].fX);
|
| 1668 | SkDebugf("%1.8g is degenerate\n", degenerate);
|
| 1669 | SkDebugf("%1.8g is length\n", length);
|
| 1670 | }
|
| 1671 | #StdOut
|
| 1672 | 0.00024414062 is degenerate
|
| 1673 | 0.00024414065 is length
|
| 1674 | #StdOut ##
|
| 1675 | ##
|
| 1676 |
|
| 1677 | ##
|
| 1678 |
|
| 1679 | # ------------------------------------------------------------------------------
|
| 1680 |
|
| 1681 | #Method bool isLine(SkPoint line[2]) const
|
| 1682 |
|
| 1683 | Returns true if Path contains only one Line;
|
| 1684 | Path_Verb array has two entries: kMove_Verb, kLine_Verb.
|
| 1685 | If Path contains one Line and line is not nullptr, line is set to
|
| 1686 | Line start point and Line end point.
|
| 1687 | Returns false if Path is not one Line; line is unaltered.
|
| 1688 |
|
| 1689 | #Param line storage for Line. May be nullptr. ##
|
| 1690 |
|
| 1691 | #Return true if Path contains exactly one Line. ##
|
| 1692 |
|
| 1693 | #Example
|
| 1694 | void draw(SkCanvas* canvas) {
|
| 1695 | auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
| 1696 | SkPoint line[2];
|
| 1697 | if (path.isLine(line)) {
|
| 1698 | SkDebugf("%s is line (%1.8g,%1.8g) (%1.8g,%1.8g)\n", prefix,
|
| 1699 | line[0].fX, line[0].fY, line[1].fX, line[1].fY);
|
| 1700 | } else {
|
| 1701 | SkDebugf("%s is not line\n", prefix);
|
| 1702 | }
|
| 1703 | };
|
| 1704 | SkPath path;
|
| 1705 | debugster("empty", path);
|
| 1706 | path.lineTo(0, 0);
|
| 1707 | debugster("zero line", path);
|
| 1708 | path.rewind();
|
| 1709 | path.moveTo(10, 10);
|
| 1710 | path.lineTo(20, 20);
|
| 1711 | debugster("line", path);
|
| 1712 | path.moveTo(20, 20);
|
| 1713 | debugster("second move", path);
|
| 1714 | }
|
| 1715 | #StdOut
|
| 1716 | empty is not line
|
| 1717 | zero line is line (0,0) (0,0)
|
| 1718 | line is line (10,10) (20,20)
|
| 1719 | second move is not line
|
| 1720 | ##
|
| 1721 | ##
|
| 1722 |
|
| 1723 | ##
|
| 1724 |
|
| 1725 | # ------------------------------------------------------------------------------
|
| 1726 |
|
| 1727 | #Subtopic Point_Array |
| 1728 | #Alias Point_Arrays |
| 1729 | |
| 1730 | Point_Array contains Points satisfying the allocated Points for |
| 1731 | each Verb in Verb_Array. For instance, Path containing one Contour with Line |
| 1732 | and Quad is described by Verb_Array: move to, line to, quad to; and |
| 1733 | one Point for move, one Point for Line, two Points for Quad; totaling four Points. |
| 1734 | |
| 1735 | Point_Array may be read directly from Path with getPoints, or inspected with |
| 1736 | getPoint, with Iter, or with RawIter. |
| 1737 |
|
| 1738 | #Method int getPoints(SkPoint points[], int max) const
|
| 1739 |
|
| 1740 | Returns number of points in Path. Up to max points are copied.
|
| 1741 | points may be nullptr; then, max must be zero.
|
| 1742 | If max is greater than number of points, excess points storage is unaltered.
|
| 1743 |
|
| 1744 | #Param points storage for Path Point array. May be nullptr. ##
|
| 1745 | #Param max Number of points alloted in points storage; must be greater than or equal to zero. ##
|
| 1746 |
|
| 1747 | #Return Path Point array length. ##
|
| 1748 |
|
| 1749 | #Example
|
| 1750 | void draw(SkCanvas* canvas) {
|
| 1751 | auto debugster = [](const char* prefix, const SkPath& path, SkPoint* points, int max) -> void {
|
| 1752 | int count = path.getPoints(points, max);
|
| 1753 | SkDebugf("%s point count: %d ", prefix, count);
|
| 1754 | for (int i = 0; i < SkTMin(count, max) && points; ++i) {
|
| 1755 | SkDebugf("(%1.8g,%1.8g) ", points[i].fX, points[i].fY);
|
| 1756 | }
|
| 1757 | SkDebugf("\n");
|
| 1758 | };
|
| 1759 | SkPath path;
|
| 1760 | path.lineTo(20, 20);
|
| 1761 | path.lineTo(-10, -10);
|
| 1762 | SkPoint points[3];
|
| 1763 | debugster("no points", path, nullptr, 0);
|
| 1764 | debugster("zero max", path, points, 0);
|
| 1765 | debugster("too small", path, points, 2);
|
| 1766 | debugster("just right", path, points, path.countPoints());
|
| 1767 | }
|
| 1768 | #StdOut
|
| 1769 | no points point count: 3
|
| 1770 | zero max point count: 3
|
| 1771 | too small point count: 3 (0,0) (20,20)
|
| 1772 | just right point count: 3 (0,0) (20,20) (-10,-10)
|
| 1773 | ##
|
| 1774 | ##
|
| 1775 |
|
| 1776 | #SeeAlso countPoints getPoint
|
| 1777 | ##
|
| 1778 |
|
| 1779 | #Method int countPoints() const
|
| 1780 |
|
| 1781 | Returns the number of points in Path.
|
| 1782 | Point count is initially zero.
|
| 1783 |
|
| 1784 | #Return Path Point array length. ##
|
| 1785 |
|
| 1786 | #Example
|
| 1787 | void draw(SkCanvas* canvas) {
|
| 1788 | auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
| 1789 | SkDebugf("%s point count: %d\n", prefix, path.countPoints());
|
| 1790 | };
|
| 1791 | SkPath path;
|
| 1792 | debugster("empty", path);
|
| 1793 | path.lineTo(0, 0);
|
| 1794 | debugster("zero line", path);
|
| 1795 | path.rewind();
|
| 1796 | path.moveTo(10, 10);
|
| 1797 | path.lineTo(20, 20);
|
| 1798 | debugster("line", path);
|
| 1799 | path.moveTo(20, 20);
|
| 1800 | debugster("second move", path);
|
| 1801 | }
|
| 1802 | #StdOut
|
| 1803 | empty point count: 0
|
| 1804 | zero line point count: 2
|
| 1805 | line point count: 2
|
| 1806 | second move point count: 3
|
| 1807 | ##
|
| 1808 | ##
|
| 1809 |
|
| 1810 | #SeeAlso getPoints
|
| 1811 | ##
|
| 1812 |
|
| 1813 | #Method SkPoint getPoint(int index) const
|
| 1814 |
|
| 1815 | Returns Point at index in Point_Array. Valid range for index is
|
| 1816 | 0 to countPoints - 1.
|
| 1817 | If the index is out of range, getPoint returns (0, 0).
|
| 1818 |
|
| 1819 | #Param index Point_Array element selector. ##
|
| 1820 |
|
| 1821 | #Return Point_Array value or (0, 0). ##
|
| 1822 |
|
| 1823 | #Example
|
| 1824 | void draw(SkCanvas* canvas) {
|
| 1825 | auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
| 1826 | SkDebugf("%s point count: %d\n", prefix, path.countPoints());
|
| 1827 | };
|
| 1828 | SkPath path;
|
| 1829 | path.lineTo(20, 20);
|
| 1830 | path.offset(-10, -10);
|
| 1831 | for (int i= 0; i < path.countPoints(); ++i) {
|
| 1832 | SkDebugf("point %d: (%1.8g,%1.8g)\n", i, path.getPoint(i).fX, path.getPoint(i).fY);
|
| 1833 | }
|
| 1834 | }
|
| 1835 | #StdOut
|
| 1836 | point 0: (-10,-10)
|
| 1837 | point 1: (10,10)
|
| 1838 | ##
|
| 1839 | ##
|
| 1840 |
|
| 1841 | #SeeAlso countPoints getPoints
|
| 1842 | ##
|
| 1843 |
|
| 1844 |
|
| 1845 | #Subtopic Point_Array ##
|
| 1846 |
|
| 1847 | # ------------------------------------------------------------------------------
|
| 1848 | #Subtopic Verb_Array |
| 1849 | |
| 1850 | Verb_Array always starts with kMove_Verb. |
| 1851 | If kClose_Verb is not the last entry, it is always followed by kMove_Verb; |
| 1852 | the quantity of kMove_Verb equals the Contour count. |
| 1853 | Verb_Array does not include or count kDone_Verb; it is a convenience |
| 1854 | returned when iterating through Verb_Array. |
| 1855 | |
| 1856 | Verb_Array may be read directly from Path with getVerbs, or inspected with Iter, |
| 1857 | or with RawIter. |
| 1858 |
|
| 1859 | #Method int countVerbs() const
|
| 1860 |
|
| 1861 | Returns the number of Verbs: kMove_Verb, kLine_Verb, kQuad_Verb, kConic_Verb,
|
| 1862 | kCubic_Verb, and kClose_Verb; added to Path.
|
| 1863 |
|
| 1864 | #Return Length of Verb_Array. ##
|
| 1865 |
|
| 1866 | #Example
|
| 1867 | SkPath path;
|
| 1868 | SkDebugf("empty verb count: %d\n", path.countVerbs());
|
| 1869 | path.addRoundRect({10, 20, 30, 40}, 5, 5);
|
| 1870 | SkDebugf("round rect verb count: %d\n", path.countVerbs());
|
| 1871 | #StdOut
|
| 1872 | empty verb count: 0
|
| 1873 | round rect verb count: 10
|
| 1874 | ##
|
| 1875 | ##
|
| 1876 |
|
| 1877 | #SeeAlso getVerbs Iter RawIter
|
| 1878 |
|
| 1879 | ##
|
| 1880 |
|
| 1881 | #Method int getVerbs(uint8_t verbs[], int max) const
|
| 1882 |
|
| 1883 | Returns the number of verbs in the path. Up to max verbs are copied. The
|
| 1884 | verbs are copied as one byte per verb.
|
| 1885 |
|
| 1886 | #Param verbs If not null, receives up to max verbs ##
|
| 1887 | #Param max The maximum number of verbs to copy into verbs ##
|
| 1888 |
|
| 1889 | #Return the actual number of verbs in the path ##
|
| 1890 |
|
| 1891 | #Example
|
| 1892 | void draw(SkCanvas* canvas) {
|
| 1893 | auto debugster = [](const char* prefix, const SkPath& path, uint8_t* verbs, int max) -> void {
|
| 1894 | int count = path.getVerbs(verbs, max);
|
| 1895 | SkDebugf("%s verb count: %d ", prefix, count);
|
| 1896 | const char* verbStr[] = { "move", "line", "quad", "conic", "cubic", "close" };
|
| 1897 | for (int i = 0; i < SkTMin(count, max) && verbs; ++i) {
|
| 1898 | SkDebugf("%s ", verbStr[verbs[i]]);
|
| 1899 | }
|
| 1900 | SkDebugf("\n");
|
| 1901 | };
|
| 1902 | SkPath path;
|
| 1903 | path.lineTo(20, 20);
|
| 1904 | path.lineTo(-10, -10);
|
| 1905 | uint8_t verbs[3];
|
| 1906 | debugster("no verbs", path, nullptr, 0);
|
| 1907 | debugster("zero max", path, verbs, 0);
|
| 1908 | debugster("too small", path, verbs, 2);
|
| 1909 | debugster("just right", path, verbs, path.countVerbs());
|
| 1910 | }
|
| 1911 | #StdOut
|
| 1912 | no verbs verb count: 3
|
| 1913 | zero max verb count: 3
|
| 1914 | too small verb count: 3 move line
|
| 1915 | just right verb count: 3 move line line
|
| 1916 | ##
|
| 1917 | ##
|
| 1918 |
|
| 1919 | #SeeAlso countVerbs getPoints Iter RawIter
|
| 1920 | ##
|
| 1921 | |
| 1922 | #Subtopic Verb_Array ## |
| 1923 |
|
| 1924 | # ------------------------------------------------------------------------------
|
| 1925 |
|
| 1926 | #Method void swap(SkPath& other)
|
| 1927 |
|
| 1928 | Exchanges the Verb_Array, Point_Array, Weights, and Fill_Type with other.
|
| 1929 | Cached state is also exchanged. swap() internally exchanges pointers, so
|
| 1930 | it is lightweight and does not allocate memory.
|
| 1931 |
|
| 1932 | swap() usage has largely been replaced by operator=(const SkPath& path).
|
| 1933 | Paths do not copy their content on assignment util they are written to,
|
| 1934 | making assignment as efficient as swap().
|
| 1935 |
|
| 1936 | #Param other Path exchanged by value. ##
|
| 1937 |
|
| 1938 | #Example
|
| 1939 | SkPath path1, path2;
|
| 1940 | path1.addRect({10, 20, 30, 40});
|
| 1941 | path1.swap(path2);
|
| 1942 | const SkRect& b1 = path1.getBounds();
|
| 1943 | SkDebugf("path1 bounds = %g, %g, %g, %g\n", b1.fLeft, b1.fTop, b1.fRight, b1.fBottom);
|
| 1944 | const SkRect& b2 = path2.getBounds();
|
| 1945 | SkDebugf("path2 bounds = %g, %g, %g, %g\n", b2.fLeft, b2.fTop, b2.fRight, b2.fBottom);
|
| 1946 | #StdOut
|
| 1947 | path1 bounds = 0, 0, 0, 0
|
| 1948 | path2 bounds = 10, 20, 30, 40
|
| 1949 | #StdOut ##
|
| 1950 | ##
|
| 1951 |
|
| 1952 | #SeeAlso operator=(const SkPath& path)
|
| 1953 |
|
| 1954 | ##
|
| 1955 |
|
| 1956 | # ------------------------------------------------------------------------------
|
| 1957 |
|
| 1958 | #Method const SkRect& getBounds() const
|
| 1959 |
|
| 1960 | Returns minimum and maximum x and y values of Point_Array. If Path contains
|
| 1961 | no points, getBounds returns (0, 0, 0, 0). Returned bounds width and height may
|
| 1962 | be larger or smaller than area affected when Path is drawn.
|
| 1963 |
|
| 1964 | getBounds includes all Points added to Path, including Points associated with
|
| 1965 | kMove_Verb that define empty Contours.
|
| 1966 |
|
| 1967 | #Return bounds of all Points in Point_Array. ##
|
| 1968 |
|
| 1969 | #Example
|
| 1970 | #Description
|
| 1971 | Bounds of upright Circle can be predicted from center and radius.
|
| 1972 | Bounds of rotated Circle includes control Points outside of filled area.
|
| 1973 | ##
|
| 1974 | auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
| 1975 | const SkRect& bounds = path.getBounds();
|
| 1976 | SkDebugf("%s bounds = %g, %g, %g, %g\n", prefix,
|
| 1977 | bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
|
| 1978 | };
|
| 1979 | SkPath path;
|
| 1980 | debugster("empty", path);
|
| 1981 | path.addCircle(50, 45, 25);
|
| 1982 | debugster("circle", path);
|
| 1983 | SkMatrix matrix;
|
| 1984 | matrix.setRotate(45, 50, 45);
|
| 1985 | path.transform(matrix);
|
| 1986 | debugster("rotated circle", path);
|
| 1987 | #StdOut
|
| 1988 | empty bounds = 0, 0, 0, 0
|
| 1989 | circle bounds = 25, 20, 75, 70
|
| 1990 | rotated circle bounds = 14.6447, 9.64466, 85.3553, 80.3553
|
| 1991 | ##
|
| 1992 | ##
|
| 1993 |
|
| 1994 | #SeeAlso computeTightBounds updateBoundsCache
|
| 1995 |
|
| 1996 | ##
|
| 1997 |
|
| 1998 | # ------------------------------------------------------------------------------
|
| 1999 |
|
| 2000 | #Method void updateBoundsCache() const
|
| 2001 |
|
| 2002 | Update internal bounds so that subsequent calls to getBounds are instantaneous.
|
| 2003 | Unaltered copies of Path may also access cached bounds through getBounds.
|
| 2004 |
|
| 2005 | For now, updateBoundsCache is identical to getBounds, where the
|
| 2006 | returned value is ignored.
|
| 2007 |
|
| 2008 | updateBoundsCache prepares a Path subsequently drawn from multiple threads,
|
| 2009 | to avoid a race condition where each draw separately computes the bounds.
|
| 2010 |
|
| 2011 | #Example
|
| 2012 | double times[2] = { 0, 0 };
|
| 2013 | for (int i = 0; i < 10000; ++i) {
|
| 2014 | SkPath path;
|
| 2015 | for (int j = 1; j < 100; ++ j) {
|
| 2016 | path.addCircle(50 + j, 45 + j, 25 + j);
|
| 2017 | }
|
| 2018 | if (1 & i) {
|
| 2019 | path.updateBoundsCache();
|
| 2020 | }
|
| 2021 | double start = SkTime::GetNSecs();
|
| 2022 | (void) path.getBounds();
|
| 2023 | times[1 & i] += SkTime::GetNSecs() - start;
|
| 2024 | }
|
| 2025 | SkDebugf("uncached avg: %g ms\n", times[0] * 1e-6);
|
| 2026 | SkDebugf("cached avg: %g ms\n", times[1] * 1e-6);
|
| 2027 | #StdOut
|
| 2028 | #Volatile
|
| 2029 | uncached avg: 0.18048 ms
|
| 2030 | cached avg: 0.182784 ms
|
| 2031 | ##
|
| 2032 | ##
|
| 2033 |
|
| 2034 | #SeeAlso getBounds
|
| 2035 | #ToDo the results don't make sense, need to profile to figure this out ##
|
| 2036 |
|
| 2037 | ##
|
| 2038 |
|
| 2039 | # ------------------------------------------------------------------------------
|
| 2040 |
|
| 2041 | #Method SkRect computeTightBounds() const
|
| 2042 |
|
| 2043 | Returns minimum and maximum x and y values of the lines and curves in Path.
|
| 2044 | If Path contains no points, computeTightBounds returns (0, 0, 0, 0).
|
| 2045 | Returned bounds width and height may be larger or smaller than area affected
|
| 2046 | when Path is drawn.
|
| 2047 |
|
| 2048 | computeTightBounds behaves identically to getBounds when Path contains
|
| 2049 | only lines. If Path contains curves, compute computeTightBounds includes
|
| 2050 | the maximum extent of the Quad, Conic, or Cubic; is slower,
|
| 2051 | and does not cache the result.
|
| 2052 |
|
| 2053 | Like getBounds, computeTightBounds includes Points associated with
|
| 2054 | kMove_Verb that define empty Contours.
|
| 2055 |
|
| 2056 | #Return ##
|
| 2057 |
|
| 2058 | #Example
|
| 2059 | auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
| 2060 | const SkRect& bounds = path.computeTightBounds();
|
| 2061 | SkDebugf("%s bounds = %g, %g, %g, %g\n", prefix,
|
| 2062 | bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
|
| 2063 | };
|
| 2064 | SkPath path;
|
| 2065 | debugster("empty", path);
|
| 2066 | path.addCircle(50, 45, 25);
|
| 2067 | debugster("circle", path);
|
| 2068 | SkMatrix matrix;
|
| 2069 | matrix.setRotate(45, 50, 45);
|
| 2070 | path.transform(matrix);
|
| 2071 | debugster("rotated circle", path);
|
| 2072 | #StdOut
|
| 2073 | empty bounds = 0, 0, 0, 0
|
| 2074 | circle bounds = 25, 20, 75, 70
|
| 2075 | rotated circle bounds = 25, 20, 75, 70
|
| 2076 | ##
|
| 2077 | ##
|
| 2078 |
|
| 2079 | #SeeAlso getBounds
|
| 2080 |
|
| 2081 | ##
|
| 2082 |
|
| 2083 | # ------------------------------------------------------------------------------
|
| 2084 |
|
| 2085 | #Method bool conservativelyContainsRect(const SkRect& rect) const
|
| 2086 |
|
| 2087 | Returns true if rect is contained by Path.
|
| 2088 | May return false when rect is contained by Path.
|
| 2089 |
|
| 2090 | For now, only returns true if Path has one Contour and is convex.
|
| 2091 | rect may share points and edges with Path and be contained.
|
| 2092 | If rect is empty, that is, it has zero width or height; conservativelyContainsRect
|
| 2093 | returns true if the Point or Line described by rect is contained by Path.
|
| 2094 |
|
| 2095 | #Param rect Rect, Line, or Point checked for containment. ##
|
| 2096 |
|
| 2097 | #Return true if rect is contained. ##
|
| 2098 |
|
| 2099 | #Example
|
| 2100 | #Height 140
|
| 2101 | #Description
|
| 2102 | Rect is drawn in blue if it is contained by red Path.
|
| 2103 | ##
|
| 2104 | void draw(SkCanvas* canvas) {
|
| 2105 | SkPath path;
|
| 2106 | path.addRoundRect({10, 20, 54, 120}, 10, 20);
|
| 2107 | SkRect tests[] = {
|
| 2108 | { 10, 40, 54, 80 },
|
| 2109 | { 25, 20, 39, 120 },
|
| 2110 | { 15, 25, 49, 115 },
|
| 2111 | { 13, 27, 51, 113 },
|
| 2112 | };
|
| 2113 | for (unsigned i = 0; i < SK_ARRAY_COUNT(tests); ++i) {
|
| 2114 | SkPaint paint;
|
| 2115 | paint.setColor(SK_ColorRED);
|
| 2116 | canvas->drawPath(path, paint);
|
| 2117 | bool rectInPath = path.conservativelyContainsRect(tests[i]);
|
| 2118 | paint.setColor(rectInPath ? SK_ColorBLUE : SK_ColorBLACK);
|
| 2119 | canvas->drawRect(tests[i], paint);
|
| 2120 | canvas->translate(64, 0);
|
| 2121 | }
|
| 2122 | }
|
| 2123 | ##
|
| 2124 |
|
| 2125 | #SeeAlso contains Op Rect Convexity
|
| 2126 |
|
| 2127 | ##
|
| 2128 |
|
| 2129 | # ------------------------------------------------------------------------------
|
| 2130 |
|
| 2131 | #Method void incReserve(unsigned extraPtCount)
|
| 2132 |
|
| 2133 | grows Path Verb_Array and Point_Array to contain extraPtCount additional Points.
|
| 2134 | incReserve may improve performance and use less memory by
|
| 2135 | reducing the number and size of allocations when creating Path.
|
| 2136 |
|
| 2137 | #Param extraPtCount number of additional Points to preallocate. ##
|
| 2138 |
|
| 2139 | #Example
|
| 2140 | #Height 192
|
| 2141 | void draw(SkCanvas* canvas) {
|
| 2142 | auto addPoly = [](int sides, SkScalar size, SkPath* path) -> void {
|
| 2143 | path->moveTo(size, 0);
|
| 2144 | for (int i = 1; i < sides; i++) {
|
| 2145 | SkScalar c, s = SkScalarSinCos(SK_ScalarPI * 2 * i / sides, &c);
|
| 2146 | path->lineTo(c * size, s * size);
|
| 2147 | }
|
| 2148 | path->close();
|
| 2149 | };
|
| 2150 | SkPath path;
|
| 2151 | path.incReserve(3 + 4 + 5 + 6 + 7 + 8 + 9);
|
| 2152 | for (int sides = 3; sides < 10; ++sides) {
|
| 2153 | addPoly(sides, sides, &path);
|
| 2154 | }
|
| 2155 | SkMatrix matrix;
|
| 2156 | matrix.setScale(10, 10, -10, -10);
|
| 2157 | path.transform(matrix);
|
| 2158 | SkPaint paint;
|
| 2159 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2160 | canvas->drawPath(path, paint);
|
| 2161 | }
|
| 2162 | ##
|
| 2163 |
|
| 2164 | #SeeAlso Point_Array
|
| 2165 |
|
| 2166 | ##
|
| 2167 |
|
| 2168 | # ------------------------------------------------------------------------------
|
| 2169 |
|
| 2170 | #Method void moveTo(SkScalar x, SkScalar y)
|
| 2171 |
|
| 2172 | Adds beginning of Contour at Point (x, y).
|
| 2173 |
|
| 2174 | #Param x x-coordinate of Contour start. ##
|
| 2175 | #Param y y-coordinate of Contour start. ##
|
| 2176 |
|
| 2177 | #Example
|
| 2178 | #Width 140
|
| 2179 | #Height 100
|
| 2180 | void draw(SkCanvas* canvas) {
|
| 2181 | SkRect rect = { 20, 20, 120, 80 };
|
| 2182 | SkPath path;
|
| 2183 | path.addRect(rect);
|
| 2184 | path.moveTo(rect.fLeft, rect.fTop);
|
| 2185 | path.lineTo(rect.fRight, rect.fBottom);
|
| 2186 | path.moveTo(rect.fLeft, rect.fBottom);
|
| 2187 | path.lineTo(rect.fRight, rect.fTop);
|
| 2188 | SkPaint paint;
|
| 2189 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2190 | canvas->drawPath(path, paint);
|
| 2191 | }
|
| 2192 | ##
|
| 2193 |
|
| 2194 | #SeeAlso Contour lineTo rMoveTo quadTo conicTo cubicTo close()
|
| 2195 |
|
| 2196 | ##
|
| 2197 |
|
| 2198 | #Method void moveTo(const SkPoint& p)
|
| 2199 |
|
| 2200 | Adds beginning of Contour at Point p.
|
| 2201 |
|
| 2202 | #Param p Contour start. ##
|
| 2203 |
|
| 2204 | #Example
|
| 2205 | #Width 128
|
| 2206 | #Height 128
|
| 2207 | void draw(SkCanvas* canvas) {
|
| 2208 | SkPoint data[][3] = {{{30,40},{60,60},{90,30}}, {{30,120},{60,100},{90,120}},
|
| 2209 | {{60,100},{60,40},{70,30}}, {{60,40},{50,20},{70,30}}};
|
| 2210 | SkPath path;
|
| 2211 | for (unsigned i = 0; i < SK_ARRAY_COUNT(data); ++i) {
|
| 2212 | path.moveTo(data[i][0]);
|
| 2213 | path.lineTo(data[i][1]);
|
| 2214 | path.lineTo(data[i][2]);
|
| 2215 | }
|
| 2216 | SkPaint paint;
|
| 2217 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2218 | canvas->drawPath(path, paint);
|
| 2219 | }
|
| 2220 | ##
|
| 2221 |
|
| 2222 | #SeeAlso Contour lineTo rMoveTo quadTo conicTo cubicTo close()
|
| 2223 |
|
| 2224 | ##
|
| 2225 |
|
| 2226 | #Method void rMoveTo(SkScalar dx, SkScalar dy)
|
| 2227 |
|
| 2228 | Adds beginning of Contour relative to Last_Point.
|
| 2229 | If Path is empty, starts Contour at (dx, dy).
|
| 2230 | Otherwise, start Contour at Last_Point offset by (dx, dy).
|
| 2231 | rMoveTo stands for relative move to.
|
| 2232 |
|
| 2233 | #Param dx offset from Last_Point x to Contour start x. ##
|
| 2234 | #Param dy offset from Last_Point y to Contour start y. ##
|
| 2235 |
|
| 2236 | #Example
|
| 2237 | #Height 100
|
| 2238 | SkPath path;
|
| 2239 | path.addRect({20, 20, 80, 80}, SkPath::kCW_Direction, 2);
|
| 2240 | path.rMoveTo(25, 2);
|
| 2241 | SkVector arrow[] = {{0, -4}, {-20, 0}, {0, -3}, {-5, 5}, {5, 5}, {0, -3}, {20, 0}};
|
| 2242 | for (unsigned i = 0; i < SK_ARRAY_COUNT(arrow); ++i) {
|
| 2243 | path.rLineTo(arrow[i].fX, arrow[i].fY);
|
| 2244 | }
|
| 2245 | SkPaint paint;
|
| 2246 | canvas->drawPath(path, paint);
|
| 2247 | SkPoint lastPt;
|
| 2248 | path.getLastPt(&lastPt);
|
| 2249 | canvas->drawString("start", lastPt.fX, lastPt.fY, paint);
|
| 2250 | ##
|
| 2251 |
|
| 2252 | #SeeAlso Contour lineTo moveTo quadTo conicTo cubicTo close()
|
| 2253 |
|
| 2254 | ##
|
| 2255 |
|
| 2256 | # ------------------------------------------------------------------------------
|
| 2257 |
|
| 2258 | #Method void lineTo(SkScalar x, SkScalar y)
|
| 2259 |
|
| 2260 | Adds Line from Last_Point to (x, y). If Path is empty, or last Verb is
|
| 2261 | kClose_Verb, Last_Point is set to (0, 0) before adding Line.
|
| 2262 |
|
| 2263 | lineTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
|
| 2264 | lineTo then appends kLine_Verb to Verb_Array and (x, y) to Point_Array.
|
| 2265 |
|
| 2266 | #Param x end of added Line in x. ##
|
| 2267 | #Param y end of added Line in y. ##
|
| 2268 |
|
| 2269 | #Example
|
| 2270 | #Height 100
|
| 2271 | ###$
|
| 2272 | void draw(SkCanvas* canvas) {
|
| 2273 | SkPaint paint;
|
| 2274 | paint.setAntiAlias(true);
|
| 2275 | paint.setTextSize(72);
|
| 2276 | canvas->drawString("#", 120, 80, paint);
|
| 2277 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2278 | paint.setStrokeWidth(5);
|
| 2279 | SkPath path;
|
| 2280 | SkPoint hash[] = {{58, 28}, {43, 80}, {37, 45}, {85, 45}};
|
| 2281 | SkVector offsets[] = {{0, 0}, {17, 0}, {0, 0}, {-5, 17}};
|
| 2282 | unsigned o = 0;
|
| 2283 | for (unsigned i = 0; i < SK_ARRAY_COUNT(hash); i += 2) {
|
| 2284 | for (unsigned j = 0; j < 2; o++, j++) {
|
| 2285 | path.moveTo(hash[i].fX + offsets[o].fX, hash[i].fY + offsets[o].fY);
|
| 2286 | path.lineTo(hash[i + 1].fX + offsets[o].fX, hash[i + 1].fY + offsets[o].fY);
|
| 2287 | }
|
| 2288 | }
|
| 2289 | canvas->drawPath(path, paint);
|
| 2290 | }
|
| 2291 | $$$#
|
| 2292 | ##
|
| 2293 |
|
| 2294 | #SeeAlso Contour moveTo rLineTo addRect
|
| 2295 |
|
| 2296 | ##
|
| 2297 |
|
| 2298 | # ------------------------------------------------------------------------------
|
| 2299 |
|
| 2300 | #Method void lineTo(const SkPoint& p)
|
| 2301 |
|
| 2302 | Adds Line from Last_Point to Point p. If Path is empty, or last Verb is
|
| 2303 | kClose_Verb, Last_Point is set to (0, 0) before adding Line.
|
| 2304 |
|
| 2305 | lineTo first appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
|
| 2306 | lineTo then appends kLine_Verb to Verb_Array and Point p to Point_Array.
|
| 2307 |
|
| 2308 | #Param p end Point of added Line. ##
|
| 2309 |
|
| 2310 | #Example
|
| 2311 | #Height 100
|
| 2312 | SkPath path;
|
| 2313 | SkVector oxo[] = {{25, 25}, {35, 35}, {25, 35}, {35, 25},
|
| 2314 | {40, 20}, {40, 80}, {60, 20}, {60, 80},
|
| 2315 | {20, 40}, {80, 40}, {20, 60}, {80, 60}};
|
| 2316 | for (unsigned i = 0; i < SK_ARRAY_COUNT(oxo); i += 2) {
|
| 2317 | path.moveTo(oxo[i]);
|
| 2318 | path.lineTo(oxo[i + 1]);
|
| 2319 | }
|
| 2320 | SkPaint paint;
|
| 2321 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2322 | canvas->drawPath(path, paint);
|
| 2323 | ##
|
| 2324 |
|
| 2325 | #SeeAlso Contour moveTo rLineTo addRect
|
| 2326 |
|
| 2327 | ##
|
| 2328 |
|
| 2329 | # ------------------------------------------------------------------------------
|
| 2330 |
|
| 2331 | #Method void rLineTo(SkScalar dx, SkScalar dy)
|
| 2332 |
|
| 2333 | Adds Line from Last_Point to Vector (dx, dy). If Path is empty, or last Verb is
|
| 2334 | kClose_Verb, Last_Point is set to (0, 0) before adding Line.
|
| 2335 |
|
| 2336 | rLineTo first appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
|
| 2337 | rLineTo then appends kLine_Verb to Verb_Array and Line end to Point_Array.
|
| 2338 | Line end is Last_Point plus Vector (dx, dy).
|
| 2339 | rLineTo stands for relative line to.
|
| 2340 |
|
| 2341 | #Param dx offset from Last_Point x to Line end x. ##
|
| 2342 | #Param dy offset from Last_Point y to Line end y. ##
|
| 2343 |
|
| 2344 | #Example
|
| 2345 | #Height 128
|
| 2346 | void draw(SkCanvas* canvas) {
|
| 2347 | SkPaint paint;
|
| 2348 | paint.setAntiAlias(true);
|
| 2349 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2350 | SkPath path;
|
| 2351 | path.moveTo(10, 98);
|
| 2352 | SkScalar x = 0, y = 0;
|
| 2353 | for (int i = 10; i < 100; i += 5) {
|
| 2354 | x += i * ((i & 2) - 1);
|
| 2355 | y += i * (((i + 1) & 2) - 1);
|
| 2356 | path.rLineTo(x, y);
|
| 2357 |
|
| 2358 | }
|
| 2359 | canvas->drawPath(path, paint);
|
| 2360 | }
|
| 2361 | ##
|
| 2362 |
|
| 2363 | #SeeAlso Contour moveTo lineTo addRect
|
| 2364 |
|
| 2365 | ##
|
| 2366 |
|
| 2367 | # ------------------------------------------------------------------------------
|
| 2368 | #Topic Quad |
| 2369 | |
| 2370 | Quad describes a quadratic Bezier, a second-order curve identical to a section |
| 2371 | of a parabola. Quad begins at a start Point, curves towards a control Point, |
| 2372 | and then curves to an end Point. |
| 2373 | |
| 2374 | #Example |
| 2375 | #Height 110 |
| 2376 | void draw(SkCanvas* canvas) {
|
| 2377 | SkPaint paint;
|
| 2378 | paint.setAntiAlias(true);
|
| 2379 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2380 | SkPoint quadPts[] = {{20, 90}, {120, 10}, {220, 90}};
|
| 2381 | canvas->drawLine(quadPts[0], quadPts[1], paint);
|
| 2382 | canvas->drawLine(quadPts[1], quadPts[2], paint);
|
| 2383 | SkPath path;
|
| 2384 | path.moveTo(quadPts[0]);
|
| 2385 | path.quadTo(quadPts[1], quadPts[2]);
|
| 2386 | paint.setStrokeWidth(3);
|
| 2387 | canvas->drawPath(path, paint);
|
| 2388 | }
|
| 2389 | ## |
| 2390 | |
| 2391 | Quad is a special case of Conic where Conic_Weight is set to one. |
| 2392 | |
| 2393 | Quad is always contained by the triangle connecting its three Points. Quad |
| 2394 | begins tangent to the line between start Point and control Point, and ends |
| 2395 | tangent to the line between control Point and end Point. |
| 2396 | |
| 2397 | #Example |
| 2398 | #Height 160 |
| 2399 | void draw(SkCanvas* canvas) {
|
| 2400 | SkPaint paint;
|
| 2401 | paint.setAntiAlias(true);
|
| 2402 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2403 | SkPoint quadPts[] = {{20, 150}, {120, 10}, {220, 150}};
|
| 2404 | SkColor colors[] = { 0xff88ff00, 0xff0088bb, 0xff6600cc, 0xffbb3377 };
|
| 2405 | for (unsigned i = 0; i < SK_ARRAY_COUNT(colors); ++i) {
|
| 2406 | paint.setColor(0x7fffffff & colors[i]);
|
| 2407 | paint.setStrokeWidth(1);
|
| 2408 | canvas->drawLine(quadPts[0], quadPts[1], paint);
|
| 2409 | canvas->drawLine(quadPts[1], quadPts[2], paint);
|
| 2410 | SkPath path;
|
| 2411 | path.moveTo(quadPts[0]);
|
| 2412 | path.quadTo(quadPts[1], quadPts[2]);
|
| 2413 | paint.setStrokeWidth(3);
|
| 2414 | paint.setColor(colors[i]);
|
| 2415 | canvas->drawPath(path, paint);
|
| 2416 | quadPts[1].fY += 30;
|
| 2417 | }
|
| 2418 | } |
| 2419 | ## |
| 2420 |
|
| 2421 | #Method void quadTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2)
|
| 2422 |
|
| 2423 | Adds Quad from Last_Point towards (x1, y1), to (x2, y2).
|
| 2424 | If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0)
|
| 2425 | before adding Quad.
|
| 2426 |
|
| 2427 | quadTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
|
| 2428 | quadTo then appends kQuad_Verb to Verb_Array; and (x1, y1), (x2, y2)
|
| 2429 | to Point_Array.
|
| 2430 |
|
| 2431 | #Param x1 control Point of Quad in x. ##
|
| 2432 | #Param y1 control Point of Quad in y. ##
|
| 2433 | #Param x2 end Point of Quad in x. ##
|
| 2434 | #Param y2 end Point of Quad in y. ##
|
| 2435 |
|
| 2436 | #Example
|
| 2437 | void draw(SkCanvas* canvas) {
|
| 2438 | SkPaint paint;
|
| 2439 | paint.setAntiAlias(true);
|
| 2440 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2441 | SkPath path;
|
| 2442 | path.moveTo(0, -10);
|
| 2443 | for (int i = 0; i < 128; i += 16) {
|
| 2444 | path.quadTo( 10 + i, -10 - i, 10 + i, 0);
|
| 2445 | path.quadTo( 14 + i, 14 + i, 0, 14 + i);
|
| 2446 | path.quadTo(-18 - i, 18 + i, -18 - i, 0);
|
| 2447 | path.quadTo(-22 - i, -22 - i, 0, -22 - i);
|
| 2448 | }
|
| 2449 | path.offset(128, 128);
|
| 2450 | canvas->drawPath(path, paint); |
| 2451 | }
|
| 2452 | ##
|
| 2453 |
|
| 2454 | #SeeAlso Contour moveTo conicTo rQuadTo
|
| 2455 |
|
| 2456 | ##
|
| 2457 |
|
| 2458 | #Method void quadTo(const SkPoint& p1, const SkPoint& p2)
|
| 2459 |
|
| 2460 | Adds Quad from Last_Point towards Point p1, to Point p2.
|
| 2461 | If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0)
|
| 2462 | before adding Quad.
|
| 2463 |
|
| 2464 | quadTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
|
| 2465 | quadTo then appends kQuad_Verb to Verb_Array; and Points p1, p2
|
| 2466 | to Point_Array.
|
| 2467 |
|
| 2468 | #Param p1 control Point of added Quad. ##
|
| 2469 | #Param p2 end Point of added Quad. ##
|
| 2470 |
|
| 2471 | #Example
|
| 2472 | void draw(SkCanvas* canvas) {
|
| 2473 | SkPaint paint;
|
| 2474 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2475 | paint.setAntiAlias(true);
|
| 2476 | SkPath path;
|
| 2477 | SkPoint pts[] = {{128, 10}, {10, 214}, {236, 214}};
|
| 2478 | path.moveTo(pts[1]);
|
| 2479 | for (int i = 0; i < 3; ++i) {
|
| 2480 | path.quadTo(pts[i % 3], pts[(i + 2) % 3]);
|
| 2481 | }
|
| 2482 | canvas->drawPath(path, paint);
|
| 2483 | }
|
| 2484 | ##
|
| 2485 |
|
| 2486 | #SeeAlso Contour moveTo conicTo rQuadTo
|
| 2487 |
|
| 2488 | ##
|
| 2489 |
|
| 2490 | #Method void rQuadTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2)
|
| 2491 |
|
| 2492 | Adds Quad from Last_Point towards Vector (dx1, dy1), to Vector (dx2, dy2).
|
| 2493 | If Path is empty, or last Verb
|
| 2494 | is kClose_Verb, Last_Point is set to (0, 0) before adding Quad.
|
| 2495 |
|
| 2496 | rQuadTo first appends kMove_Verb to Verb_Array and (0, 0) to Point_Array,
|
| 2497 | if needed. rQuadTo then appends kQuad_Verb to Verb_Array; and appends Quad
|
| 2498 | control and Quad end to Point_Array.
|
| 2499 | Quad control is Last_Point plus Vector (dx1, dy1).
|
| 2500 | Quad end is Last_Point plus Vector (dx2, dy2).
|
| 2501 | rQuadTo stands for relative quad to.
|
| 2502 |
|
| 2503 | #Param dx1 offset from Last_Point x to Quad control x. ##
|
| 2504 | #Param dy1 offset from Last_Point x to Quad control y. ##
|
| 2505 | #Param dx2 offset from Last_Point x to Quad end x. ##
|
| 2506 | #Param dy2 offset from Last_Point x to Quad end y. ##
|
| 2507 |
|
| 2508 | #Example
|
| 2509 | void draw(SkCanvas* canvas) {
|
| 2510 | SkPaint paint;
|
| 2511 | paint.setAntiAlias(true);
|
| 2512 | SkPath path;
|
| 2513 | path.moveTo(128, 20);
|
| 2514 | path.rQuadTo(-6, 10, -7, 10);
|
| 2515 | for (int i = 1; i < 32; i += 4) {
|
| 2516 | path.rQuadTo(10 + i, 10 + i, 10 + i * 4, 10);
|
| 2517 | path.rQuadTo(-10 - i, 10 + i, -10 - (i + 2) * 4, 10);
|
| 2518 | }
|
| 2519 | path.quadTo(92, 220, 128, 215);
|
| 2520 | canvas->drawPath(path, paint);
|
| 2521 | }
|
| 2522 | ##
|
| 2523 |
|
| 2524 | #SeeAlso Contour moveTo conicTo quadTo
|
| 2525 |
|
| 2526 | ##
|
| 2527 |
|
| 2528 | #Topic Quad ## |
| 2529 |
|
| 2530 | # ------------------------------------------------------------------------------
|
| 2531 |
|
| 2532 | #Topic Conic |
| 2533 | #Alias Conics |
| 2534 | |
| 2535 | Conic describes a conical section: a piece of an ellipse, or a piece of a |
| 2536 | parabola, or a piece of a hyperbola. Conic begins at a start Point, |
| 2537 | curves towards a control Point, and then curves to an end Point. The influence |
| 2538 | of the control Point is determined by Conic_Weight. |
| 2539 | |
| 2540 | Each Conic in Path adds two Points and one Weight. Weights in Path may be |
| 2541 | inspected with Iter, or with RawIter. |
| 2542 | |
| 2543 | #Subtopic Weight |
| 2544 | #Alias Weights |
| 2545 | |
| 2546 | Weight determines both the strength of the control Point and the type of Conic. |
| 2547 | If Weight is exactly one, then Conic is identical to Quad; it is always a |
| 2548 | parabolic segment. |
| 2549 | |
| 2550 | |
| 2551 | |
| 2552 | #Example |
| 2553 | #Description |
| 2554 | When Conic weight is one, Quad is added to path; the two are identical. |
| 2555 | ## |
| 2556 | void draw(SkCanvas* canvas) {
|
| 2557 | const char* verbNames[] = { "move", "line", "quad", "conic", "cubic", "close", "done" };
|
| 2558 | const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
| 2559 | SkPath path;
|
| 2560 | path.conicTo(20, 30, 50, 60, 1);
|
| 2561 | SkPath::Iter iter(path, false);
|
| 2562 | SkPath::Verb verb;
|
| 2563 | do {
|
| 2564 | SkPoint points[4];
|
| 2565 | verb = iter.next(points);
|
| 2566 | SkDebugf("%s ", verbNames[(int) verb]);
|
| 2567 | for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
| 2568 | SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
|
| 2569 | }
|
| 2570 | if (SkPath::kConic_Verb == verb) {
|
| 2571 | SkDebugf("weight = %g", iter.conicWeight());
|
| 2572 | }
|
| 2573 | SkDebugf("\n");
|
| 2574 | } while (SkPath::kDone_Verb != verb);
|
| 2575 | } |
| 2576 | #StdOut |
| 2577 | move {0, 0},
|
| 2578 | quad {0, 0}, {20, 30}, {50, 60},
|
| 2579 | done |
| 2580 | ## |
| 2581 | ## |
| 2582 | |
| 2583 | If weight is less than one, Conic is an elliptical segment. |
| 2584 | |
| 2585 | #Example |
| 2586 | #Description |
| 2587 | A 90 degree circular arc has the weight |
| 2588 | #Formula |
| 2589 | 1 / sqrt(2) |
| 2590 | ## |
| 2591 | . |
| 2592 | ## |
| 2593 | void draw(SkCanvas* canvas) {
|
| 2594 | const char* verbNames[] = { "move", "line", "quad", "conic", "cubic", "close", "done" };
|
| 2595 | const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
| 2596 | SkPath path;
|
| 2597 | path.arcTo(20, 0, 20, 20, 20);
|
| 2598 | SkPath::Iter iter(path, false);
|
| 2599 | SkPath::Verb verb;
|
| 2600 | do {
|
| 2601 | SkPoint points[4];
|
| 2602 | verb = iter.next(points);
|
| 2603 | SkDebugf("%s ", verbNames[(int) verb]);
|
| 2604 | for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
| 2605 | SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
|
| 2606 | }
|
| 2607 | if (SkPath::kConic_Verb == verb) {
|
| 2608 | SkDebugf("weight = %g", iter.conicWeight());
|
| 2609 | }
|
| 2610 | SkDebugf("\n");
|
| 2611 | } while (SkPath::kDone_Verb != verb);
|
| 2612 | } |
| 2613 | #StdOut |
| 2614 | move {0, 0},
|
| 2615 | conic {0, 0}, {20, 0}, {20, 20}, weight = 0.707107
|
| 2616 | done |
| 2617 | ## |
| 2618 | ## |
| 2619 | |
| 2620 | If weight is greater than one, Conic is a hyperbolic segment. As w gets large, |
| 2621 | a hyperbolic segment can be approximated by straight lines connecting the |
| 2622 | control Point with the end Points. |
| 2623 | |
| 2624 | #Example |
| 2625 | void draw(SkCanvas* canvas) {
|
| 2626 | const char* verbNames[] = { "move", "line", "quad", "conic", "cubic", "close", "done" };
|
| 2627 | const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
| 2628 | SkPath path;
|
| 2629 | path.conicTo(20, 0, 20, 20, SK_ScalarInfinity);
|
| 2630 | SkPath::Iter iter(path, false);
|
| 2631 | SkPath::Verb verb;
|
| 2632 | do {
|
| 2633 | SkPoint points[4];
|
| 2634 | verb = iter.next(points);
|
| 2635 | SkDebugf("%s ", verbNames[(int) verb]);
|
| 2636 | for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
| 2637 | SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
|
| 2638 | }
|
| 2639 | if (SkPath::kConic_Verb == verb) {
|
| 2640 | SkDebugf("weight = %g", iter.conicWeight());
|
| 2641 | }
|
| 2642 | SkDebugf("\n");
|
| 2643 | } while (SkPath::kDone_Verb != verb);
|
| 2644 | } |
| 2645 | #StdOut |
| 2646 | move {0, 0},
|
| 2647 | line {0, 0}, {20, 0},
|
| 2648 | line {20, 0}, {20, 20},
|
| 2649 | done |
| 2650 | ## |
| 2651 | ## |
| 2652 | |
| 2653 | #Subtopic Weight ## |
| 2654 |
|
| 2655 | #Method void conicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
|
| 2656 | SkScalar w)
|
| 2657 |
|
| 2658 | Adds Conic from Last_Point towards (x1, y1), to (x2, y2), weighted by w.
|
| 2659 | If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0)
|
| 2660 | before adding Conic.
|
| 2661 |
|
| 2662 | conicTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
|
| 2663 |
|
| 2664 | If w is finite and not one, conicTo then appends kConic_Verb to Verb_Array;
|
| 2665 | and (x1, y1), (x2, y2) to Point_Array; and w to Weights.
|
| 2666 |
|
| 2667 | If w is one, conicTo appends kQuad_Verb to Verb_Array, and
|
| 2668 | (x1, y1), (x2, y2) to Point_Array.
|
| 2669 |
|
| 2670 | If w is not finite, conicTo appends kLine_Verb twice to Verb_Array, and
|
| 2671 | (x1, y1), (x2, y2) to Point_Array.
|
| 2672 |
|
| 2673 | #Param x1 control Point of Conic in x. ##
|
| 2674 | #Param y1 control Point of Conic in y. ##
|
| 2675 | #Param x2 end Point of Conic in x. ##
|
| 2676 | #Param y2 end Point of Conic in y. ##
|
| 2677 | #Param w weight of added Conic. ##
|
| 2678 |
|
| 2679 | #Example
|
| 2680 | #Height 160 |
| 2681 | #Description
|
| 2682 | As weight increases, curve is pulled towards control point.
|
| 2683 | The bottom two curves are elliptical; the next is parabolic; the
|
| 2684 | top curve is hyperbolic.
|
| 2685 | ##
|
| 2686 | void draw(SkCanvas* canvas) {
|
| 2687 | SkPaint paint;
|
| 2688 | paint.setAntiAlias(true);
|
| 2689 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2690 | SkPoint conicPts[] = {{20, 150}, {120, 10}, {220, 150}};
|
| 2691 | canvas->drawLine(conicPts[0], conicPts[1], paint);
|
| 2692 | canvas->drawLine(conicPts[1], conicPts[2], paint);
|
| 2693 | SkColor colors[] = { 0xff88ff00, 0xff0088bb, 0xff6600cc, 0xffbb3377 };
|
| 2694 | paint.setStrokeWidth(3);
|
| 2695 | SkScalar weight = 0.5f;
|
| 2696 | for (unsigned i = 0; i < SK_ARRAY_COUNT(colors); ++i) {
|
| 2697 | SkPath path;
|
| 2698 | path.moveTo(conicPts[0]);
|
| 2699 | path.conicTo(conicPts[1], conicPts[2], weight);
|
| 2700 | paint.setColor(colors[i]);
|
| 2701 | canvas->drawPath(path, paint);
|
| 2702 | weight += 0.25f;
|
| 2703 | }
|
| 2704 | }
|
| 2705 | ##
|
| 2706 |
|
| 2707 | #SeeAlso rConicTo arcTo addArc quadTo
|
| 2708 |
|
| 2709 | ##
|
| 2710 |
|
| 2711 | #Method void conicTo(const SkPoint& p1, const SkPoint& p2, SkScalar w)
|
| 2712 |
|
| 2713 | Adds Conic from Last_Point towards Point p1, to Point p2, weighted by w.
|
| 2714 | If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0)
|
| 2715 | before adding Conic.
|
| 2716 |
|
| 2717 | conicTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
|
| 2718 |
|
| 2719 | If w is finite and not one, conicTo then appends kConic_Verb to Verb_Array;
|
| 2720 | and Points p1, p2 to Point_Array; and w to Weights.
|
| 2721 |
|
| 2722 | If w is one, conicTo appends kQuad_Verb to Verb_Array, and Points p1, p2
|
| 2723 | to Point_Array.
|
| 2724 |
|
| 2725 | If w is not finite, conicTo appends kLine_Verb twice to Verb_Array, and
|
| 2726 | Points p1, p2 to Point_Array.
|
| 2727 |
|
| 2728 | #Param p1 control Point of added Conic. ##
|
| 2729 | #Param p2 end Point of added Conic. ##
|
| 2730 | #Param w weight of added Conic. ##
|
| 2731 |
|
| 2732 | #Example
|
| 2733 | #Height 128 |
| 2734 | #Description
|
| 2735 | Conics and arcs use identical representations. As the arc sweep increases
|
| 2736 | the conic weight also increases, but remains smaller than one.
|
| 2737 | ##
|
| 2738 | void draw(SkCanvas* canvas) {
|
| 2739 | SkPaint paint;
|
| 2740 | paint.setAntiAlias(true);
|
| 2741 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2742 | SkRect oval = {0, 20, 120, 140};
|
| 2743 | SkPath path;
|
| 2744 | for (int i = 0; i < 4; ++i) {
|
| 2745 | path.moveTo(oval.centerX(), oval.fTop);
|
| 2746 | path.arcTo(oval, -90, 90 - 20 * i, false);
|
| 2747 | oval.inset(15, 15);
|
| 2748 | }
|
| 2749 | path.offset(100, 0);
|
| 2750 | SkScalar conicWeights[] = { 0.707107f, 0.819152f, 0.906308f, 0.965926f };
|
| 2751 | SkPoint conicPts[][3] = { { {40, 20}, {100, 20}, {100, 80} },
|
| 2752 | { {40, 35}, {71.509f, 35}, {82.286f, 64.6091f} },
|
| 2753 | { {40, 50}, {53.9892f, 50}, {62.981f, 60.7164f} },
|
| 2754 | { {40, 65}, {44.0192f, 65}, {47.5f, 67.0096f} } };
|
| 2755 | for (int i = 0; i < 4; ++i) {
|
| 2756 | path.moveTo(conicPts[i][0]);
|
| 2757 | path.conicTo(conicPts[i][1], conicPts[i][2], conicWeights[i]);
|
| 2758 | }
|
| 2759 | canvas->drawPath(path, paint);
|
| 2760 | }
|
| 2761 | ##
|
| 2762 |
|
| 2763 | #SeeAlso rConicTo arcTo addArc quadTo
|
| 2764 |
|
| 2765 | ##
|
| 2766 |
|
| 2767 | #Method void rConicTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2,
|
| 2768 | SkScalar w)
|
| 2769 |
|
| 2770 | Adds Conic from Last_Point towards Vector (dx1, dy1), to Vector (dx2, dy2),
|
| 2771 | weighted by w. If Path is empty, or last Verb
|
| 2772 | is kClose_Verb, Last_Point is set to (0, 0) before adding Conic.
|
| 2773 |
|
| 2774 | rConicTo first appends kMove_Verb to Verb_Array and (0, 0) to Point_Array,
|
| 2775 | if needed.
|
| 2776 |
|
| 2777 | If w is finite and not one, rConicTo then appends kConic_Verb to Verb_Array,
|
| 2778 | and w is recorded as Conic_Weight; otherwise, if w is one, rConicTo appends
|
| 2779 | kQuad_Verb to Verb_Array; or if w is not finite, rConicTo appends kLine_Verb
|
| 2780 | twice to Verb_Array.
|
| 2781 |
|
| 2782 | In all cases rConicTo then appends Points control and end to Point_Array.
|
| 2783 | control is Last_Point plus Vector (dx1, dy1).
|
| 2784 | end is Last_Point plus Vector (dx2, dy2).
|
| 2785 |
|
| 2786 | rConicTo stands for relative conic to.
|
| 2787 |
|
| 2788 | #Param dx1 offset from Last_Point x to Conic control x. ##
|
| 2789 | #Param dy1 offset from Last_Point x to Conic control y. ##
|
| 2790 | #Param dx2 offset from Last_Point x to Conic end x. ##
|
| 2791 | #Param dy2 offset from Last_Point x to Conic end y. ##
|
| 2792 | #Param w weight of added Conic. ##
|
| 2793 |
|
| 2794 | #Example
|
| 2795 | #Height 140
|
| 2796 | void draw(SkCanvas* canvas) {
|
| 2797 | SkPaint paint;
|
| 2798 | paint.setAntiAlias(true);
|
| 2799 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2800 | SkPath path;
|
| 2801 | path.moveTo(20, 80);
|
| 2802 | path.rConicTo( 60, 0, 60, 60, 0.707107f);
|
| 2803 | path.rConicTo( 0, -60, 60, -60, 0.707107f);
|
| 2804 | path.rConicTo(-60, 0, -60, -60, 0.707107f);
|
| 2805 | path.rConicTo( 0, 60, -60, 60, 0.707107f);
|
| 2806 | canvas->drawPath(path, paint);
|
| 2807 | }
|
| 2808 | ##
|
| 2809 |
|
| 2810 | #SeeAlso conicTo arcTo addArc quadTo
|
| 2811 |
|
| 2812 | ##
|
| 2813 |
|
| 2814 | #Topic Conic ##
|
| 2815 |
|
| 2816 | # ------------------------------------------------------------------------------
|
| 2817 | #Topic Cubic |
| 2818 | #Alias Cubics |
| 2819 | |
| 2820 | Cubic describes a cubic Bezier, a third-order curve. |
| 2821 | Cubic begins at a start Point, curving towards the first control Point; |
| 2822 | and curves from the end Point towards the second control Point. |
| 2823 | |
| 2824 | #Example |
| 2825 | #Height 160 |
| 2826 | void draw(SkCanvas* canvas) {
|
| 2827 | SkPaint paint;
|
| 2828 | paint.setAntiAlias(true);
|
| 2829 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2830 | SkPoint cubicPts[] = {{20, 150}, {90, 10}, {160, 150}, {230, 10}};
|
| 2831 | SkColor colors[] = { 0xff88ff00, 0xff0088bb, 0xff6600cc, 0xffbb3377 };
|
| 2832 | for (unsigned i = 0; i < SK_ARRAY_COUNT(colors); ++i) {
|
| 2833 | paint.setColor(0x7fffffff & colors[i]);
|
| 2834 | paint.setStrokeWidth(1);
|
| 2835 | for (unsigned j = 0; j < 3; ++j) {
|
| 2836 | canvas->drawLine(cubicPts[j], cubicPts[j + 1], paint);
|
| 2837 | }
|
| 2838 | SkPath path;
|
| 2839 | path.moveTo(cubicPts[0]);
|
| 2840 | path.cubicTo(cubicPts[1], cubicPts[2], cubicPts[3]);
|
| 2841 | paint.setStrokeWidth(3);
|
| 2842 | paint.setColor(colors[i]);
|
| 2843 | canvas->drawPath(path, paint);
|
| 2844 | cubicPts[1].fY += 30;
|
| 2845 | cubicPts[2].fX += 30;
|
| 2846 | }
|
| 2847 | } |
| 2848 | ## |
| 2849 |
|
| 2850 | #Method void cubicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
|
| 2851 | SkScalar x3, SkScalar y3)
|
| 2852 |
|
| 2853 | Adds Cubic from Last_Point towards (x1, y1), then towards (x2, y2), ending at
|
| 2854 | (x3, y3). If Path is empty, or last Verb is kClose_Verb, Last_Point is set to
|
| 2855 | (0, 0) before adding Cubic.
|
| 2856 |
|
| 2857 | cubicTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
|
| 2858 | cubicTo then appends kCubic_Verb to Verb_Array; and (x1, y1), (x2, y2), (x3, y3)
|
| 2859 | to Point_Array.
|
| 2860 |
|
| 2861 | #Param x1 first control Point of Cubic in x. ##
|
| 2862 | #Param y1 first control Point of Cubic in y. ##
|
| 2863 | #Param x2 second control Point of Cubic in x. ##
|
| 2864 | #Param y2 second control Point of Cubic in y. ##
|
| 2865 | #Param x3 end Point of Cubic in x. ##
|
| 2866 | #Param y3 end Point of Cubic in y. ##
|
| 2867 |
|
| 2868 | #Example
|
| 2869 | void draw(SkCanvas* canvas) {
|
| 2870 | SkPaint paint;
|
| 2871 | paint.setAntiAlias(true);
|
| 2872 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2873 | SkPath path;
|
| 2874 | path.moveTo(0, -10);
|
| 2875 | for (int i = 0; i < 128; i += 16) {
|
| 2876 | SkScalar c = i * 0.5f;
|
| 2877 | path.cubicTo( 10 + c, -10 - i, 10 + i, -10 - c, 10 + i, 0);
|
| 2878 | path.cubicTo( 14 + i, 14 + c, 14 + c, 14 + i, 0, 14 + i);
|
| 2879 | path.cubicTo(-18 - c, 18 + i, -18 - i, 18 + c, -18 - i, 0);
|
| 2880 | path.cubicTo(-22 - i, -22 - c, -22 - c, -22 - i, 0, -22 - i);
|
| 2881 | }
|
| 2882 | path.offset(128, 128);
|
| 2883 | canvas->drawPath(path, paint);
|
| 2884 | }
|
| 2885 | ##
|
| 2886 |
|
| 2887 | #SeeAlso Contour moveTo rCubicTo quadTo
|
| 2888 |
|
| 2889 | ##
|
| 2890 |
|
| 2891 | # ------------------------------------------------------------------------------
|
| 2892 |
|
| 2893 | #Method void cubicTo(const SkPoint& p1, const SkPoint& p2, const SkPoint& p3)
|
| 2894 |
|
| 2895 | Adds Cubic from Last_Point towards Point p1, then towards Point p2, ending at
|
| 2896 | Point p3. If Path is empty, or last Verb is kClose_Verb, Last_Point is set to
|
| 2897 | (0, 0) before adding Cubic.
|
| 2898 |
|
| 2899 | cubicTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
|
| 2900 | cubicTo then appends kCubic_Verb to Verb_Array; and Points p1, p2, p3
|
| 2901 | to Point_Array.
|
| 2902 |
|
| 2903 | #Param p1 first control Point of Cubic. ##
|
| 2904 | #Param p2 second control Point of Cubic. ##
|
| 2905 | #Param p3 end Point of Cubic. ##
|
| 2906 |
|
| 2907 | #Example
|
| 2908 | #Height 84
|
| 2909 | SkPaint paint;
|
| 2910 | paint.setAntiAlias(true);
|
| 2911 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2912 | SkPoint pts[] = { {20, 20}, {300, 80}, {-140, 90}, {220, 10} };
|
| 2913 | SkPath path;
|
| 2914 | path.moveTo(pts[0]);
|
| 2915 | path.cubicTo(pts[1], pts[2], pts[3]);
|
| 2916 | canvas->drawPath(path, paint);
|
| 2917 | ##
|
| 2918 |
|
| 2919 | #SeeAlso Contour moveTo rCubicTo quadTo
|
| 2920 |
|
| 2921 | ##
|
| 2922 |
|
| 2923 | # ------------------------------------------------------------------------------
|
| 2924 |
|
| 2925 | #Method void rCubicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
|
| 2926 | SkScalar x3, SkScalar y3)
|
| 2927 |
|
| 2928 | Adds Cubic from Last_Point towards Vector (dx1, dy1), then towards
|
| 2929 | Vector (dx2, dy2), to Vector (dx3, dy3).
|
| 2930 | If Path is empty, or last Verb
|
| 2931 | is kClose_Verb, Last_Point is set to (0, 0) before adding Cubic.
|
| 2932 |
|
| 2933 | rCubicTo first appends kMove_Verb to Verb_Array and (0, 0) to Point_Array,
|
| 2934 | if needed. rCubicTo then appends kCubic_Verb to Verb_Array; and appends Cubic
|
| 2935 | control and Cubic end to Point_Array.
|
| 2936 | Cubic control is Last_Point plus Vector (dx1, dy1).
|
| 2937 | Cubic end is Last_Point plus Vector (dx2, dy2).
|
| 2938 | rCubicTo stands for relative cubic to.
|
| 2939 |
|
| 2940 | #Param x1 offset from Last_Point x to first Cubic control x. ##
|
| 2941 | #Param y1 offset from Last_Point x to first Cubic control y. ##
|
| 2942 | #Param x2 offset from Last_Point x to second Cubic control x. ##
|
| 2943 | #Param y2 offset from Last_Point x to second Cubic control y. ##
|
| 2944 | #Param x3 offset from Last_Point x to Cubic end x. ##
|
| 2945 | #Param y3 offset from Last_Point x to Cubic end y. ##
|
| 2946 |
|
| 2947 | #Example
|
| 2948 | void draw(SkCanvas* canvas) {
|
| 2949 | SkPaint paint;
|
| 2950 | paint.setAntiAlias(true);
|
| 2951 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2952 | SkPath path;
|
| 2953 | path.moveTo(24, 108);
|
| 2954 | for (int i = 0; i < 16; i++) {
|
| 2955 | SkScalar sx, sy;
|
| 2956 | sx = SkScalarSinCos(i * SK_ScalarPI / 8, &sy);
|
| 2957 | path.rCubicTo(40 * sx, 4 * sy, 4 * sx, 40 * sy, 40 * sx, 40 * sy);
|
| 2958 | }
|
| 2959 | canvas->drawPath(path, paint);
|
| 2960 | }
|
| 2961 | ##
|
| 2962 |
|
| 2963 | #SeeAlso Contour moveTo cubicTo quadTo
|
| 2964 |
|
| 2965 | ##
|
| 2966 |
|
| 2967 | #Topic Cubic ##
|
| 2968 |
|
| 2969 | # ------------------------------------------------------------------------------
|
| 2970 |
|
| 2971 | #Topic Arc
|
| 2972 |
|
| 2973 | Arc can be constructed in a number of ways. Arc may be described by part of Oval and angles,
|
| 2974 | by start point and end point, and by radius and tangent lines. Each construction has advantages,
|
| 2975 | and some constructions correspond to Arc drawing in graphics standards.
|
| 2976 |
|
| 2977 | All Arc draws are implemented by one or more Conic draws. When Conic_Weight is less than one,
|
| 2978 | Conic describes an Arc of some Oval or Circle.
|
| 2979 |
|
| 2980 | arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo)
|
| 2981 | describes Arc as a piece of Oval, beginning at start angle, sweeping clockwise or counterclockwise,
|
| 2982 | which may continue Contour or start a new one. This construction is similar to PostScript and
|
| 2983 | HTML_Canvas arcs. Variation addArc always starts new Contour. Canvas::drawArc draws without
|
| 2984 | requiring Path.
|
| 2985 |
|
| 2986 | arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius)
|
| 2987 | describes Arc as tangent to the line (x0, y0), (x1, y1) and tangent to the line (x1, y1), (x2, y2)
|
| 2988 | where (x0, y0) is the last Point added to Path. This construction is similar to PostScript and
|
| 2989 | HTML_Canvas arcs.
|
| 2990 |
|
| 2991 | arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep,
|
| 2992 | SkScalar x, SkScalar y)
|
| 2993 | describes Arc as part of Oval with radii (rx, ry), beginning at
|
| 2994 | last Point added to Path and ending at (x, y). More than one Arc satisfies this criteria,
|
| 2995 | so additional values choose a single solution. This construction is similar to SVG arcs.
|
| 2996 |
|
| 2997 | conicTo describes Arc of less than 180 degrees as a pair of tangent lines and Conic_Weight.
|
| 2998 | conicTo can represent any Arc with a sweep less than 180 degrees at any rotation. All arcTo
|
| 2999 | constructions are converted to Conic data when added to Path.
|
| 3000 |
|
| 3001 | #ToDo allow example to hide source and not be exposed as fiddle since markdown / html can't
|
| 3002 | do the kind of table shown in the illustration.
|
| 3003 | example is spaced correctly on fiddle but spacing is too wide on pc
|
| 3004 | ##
|
| 3005 |
|
| 3006 | #Example
|
| 3007 | #Height 300
|
| 3008 | #Width 600
|
| 3009 | #Description
|
| 3010 | #List
|
| 3011 | # <sup>1</sup> arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo) ##
|
| 3012 | # <sup>2</sup> parameter sets force MoveTo ##
|
| 3013 | # <sup>3</sup> start angle must be multiple of 90 degrees. ##
|
| 3014 | # <sup>4</sup> arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius) ##
|
| 3015 | # <sup>5</sup> arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc,
|
| 3016 | Direction sweep, SkScalar x, SkScalar y) ##
|
| 3017 | #List ##
|
| 3018 | #Description ##
|
| 3019 | #Function
|
| 3020 | struct data {
|
| 3021 | const char* name;
|
| 3022 | char super;
|
| 3023 | int yn[10];
|
| 3024 | };
|
| 3025 |
|
| 3026 | const data dataSet[] = {
|
| 3027 | { "arcTo sweep", '1', {1, 3, 1, 0, 0, 0, 0, 1, 0, 0 }},
|
| 3028 | { "drawArc", 0, {1, -1, 1, 1, 1, 1, 1, 0, 0, 0 }},
|
| 3029 | { "addArc", 0, {1, 1, 1, 4, 0, 1, 1, 1, 0, 0 }},
|
| 3030 | { "arcTo tangents", '4', {0, 0, 0, 0, 0, 0, 0, 1, 1, 0 }},
|
| 3031 | { "arcTo radii", '5', {1, 0, 1, 0, 0, 0, 0, 1, 1, 0 }},
|
| 3032 | { "conicTo", 0, {1, 1, 0, 0, 0, 0, 0, 1, 1, 1 }}
|
| 3033 | };
|
| 3034 |
|
| 3035 | #define __degree_symbol__ "\xC2" "\xB0"
|
| 3036 |
|
| 3037 | const char* headers[] = {
|
| 3038 | "Oval part",
|
| 3039 | "force moveTo",
|
| 3040 | "can draw 180" __degree_symbol__,
|
| 3041 | "can draw 360" __degree_symbol__,
|
| 3042 | "can draw greater than 360" __degree_symbol__,
|
| 3043 | "ignored if radius is zero",
|
| 3044 | "ignored if sweep is zero",
|
| 3045 | "requires Path",
|
| 3046 | "describes rotation",
|
| 3047 | "describes perspective",
|
| 3048 | };
|
| 3049 |
|
| 3050 | const char* yna[] = {
|
| 3051 | "n/a",
|
| 3052 | "no",
|
| 3053 | "yes"
|
| 3054 | };
|
| 3055 |
|
| 3056 | ##
|
| 3057 | void draw(SkCanvas* canvas) {
|
| 3058 | SkPaint lp;
|
| 3059 | lp.setAntiAlias(true);
|
| 3060 | SkPaint tp(lp);
|
| 3061 | SkPaint sp(tp);
|
| 3062 | SkPaint bp(tp);
|
| 3063 | bp.setFakeBoldText(true);
|
| 3064 | sp.setTextSize(10);
|
| 3065 | lp.setColor(SK_ColorGRAY);
|
| 3066 | canvas->translate(0, 32);
|
| 3067 | const int tl = 115;
|
| 3068 | for (unsigned col = 0; col <= SK_ARRAY_COUNT(headers); ++col) {
|
| 3069 | canvas->drawLine(tl + col * 35, 100, tl + col * 35, 250, lp);
|
| 3070 | if (0 == col) {
|
| 3071 | continue;
|
| 3072 | }
|
| 3073 | canvas->drawLine(tl + col * 35, 100, tl + 100 + col * 35, 0, lp);
|
| 3074 | SkPath path;
|
| 3075 | path.moveTo(tl - 3 + col * 35, 103);
|
| 3076 | path.lineTo(tl + 124 + col * 35, -24);
|
| 3077 | canvas->drawTextOnPathHV(headers[col -1], strlen(headers[col -1]), path, 0, -9, bp);
|
| 3078 | }
|
| 3079 | for (unsigned row = 0; row <= SK_ARRAY_COUNT(dataSet); ++row) {
|
| 3080 | if (0 == row) {
|
| 3081 | canvas->drawLine(tl, 100, tl + 350, 100, lp);
|
| 3082 | } else {
|
| 3083 | canvas->drawLine(5, 100 + row * 25, tl + 350, 100 + row * 25, lp);
|
| 3084 | }
|
| 3085 | if (row == SK_ARRAY_COUNT(dataSet)) {
|
| 3086 | break;
|
| 3087 | }
|
| 3088 | canvas->drawString(dataSet[row].name, 5, 117 + row * 25, bp);
|
| 3089 | if (dataSet[row].super) {
|
| 3090 | SkScalar width = bp.measureText(dataSet[row].name, strlen(dataSet[row].name));
|
| 3091 | canvas->drawText(&dataSet[row].super, 1, 8 + width, 112 + row * 25, sp);
|
| 3092 | }
|
| 3093 | for (unsigned col = 0; col < SK_ARRAY_COUNT(headers); ++col) {
|
| 3094 | int val = dataSet[row].yn[col];
|
| 3095 | canvas->drawString(yna[SkTMin(2, val + 1)], tl + 5 + col * 35, 117 + row * 25, tp);
|
| 3096 | if (val > 1) {
|
| 3097 | char supe = '0' + val - 1;
|
| 3098 | canvas->drawText(&supe, 1, tl + 25 + col * 35, 112 + row * 25, sp);
|
| 3099 | }
|
| 3100 | }
|
| 3101 | }
|
| 3102 | }
|
| 3103 | #Example ##
|
| 3104 |
|
| 3105 | #Example
|
| 3106 | #Height 128
|
| 3107 | #Description
|
| 3108 | #ToDo make this a list or table ##
|
| 3109 | 1 describes an arc from an oval, a starting angle, and a sweep angle.
|
| 3110 | 2 is similar to 1, but does not require building a path to draw.
|
| 3111 | 3 is similar to 1, but always begins new Contour.
|
| 3112 | 4 describes an arc from a pair of tangent lines and a radius.
|
| 3113 | 5 describes an arc from Oval center, arc start Point and arc end Point.
|
| 3114 | 6 describes an arc from a pair of tangent lines and a Conic_Weight.
|
| 3115 | ##
|
| 3116 | void draw(SkCanvas* canvas) {
|
| 3117 | SkRect oval = {8, 8, 56, 56};
|
| 3118 | SkPaint ovalPaint;
|
| 3119 | ovalPaint.setAntiAlias(true);
|
| 3120 | SkPaint textPaint(ovalPaint);
|
| 3121 | ovalPaint.setStyle(SkPaint::kStroke_Style);
|
| 3122 | SkPaint arcPaint(ovalPaint);
|
| 3123 | arcPaint.setStrokeWidth(5);
|
| 3124 | arcPaint.setColor(SK_ColorBLUE);
|
| 3125 | canvas->translate(-64, 0);
|
| 3126 | for (char arcStyle = '1'; arcStyle <= '6'; ++arcStyle) {
|
| 3127 | '4' == arcStyle ? canvas->translate(-96, 55) : canvas->translate(64, 0);
|
| 3128 | canvas->drawText(&arcStyle, 1, 30, 36, textPaint);
|
| 3129 | canvas->drawOval(oval, ovalPaint);
|
| 3130 | SkPath path;
|
| 3131 | path.moveTo({56, 32});
|
| 3132 | switch (arcStyle) {
|
| 3133 | case '1':
|
| 3134 | path.arcTo(oval, 0, 90, false);
|
| 3135 | break;
|
| 3136 | case '2':
|
| 3137 | canvas->drawArc(oval, 0, 90, false, arcPaint);
|
| 3138 | continue;
|
| 3139 | case '3':
|
| 3140 | path.addArc(oval, 0, 90);
|
| 3141 | break;
|
| 3142 | case '4':
|
| 3143 | path.arcTo({56, 56}, {32, 56}, 24);
|
| 3144 | break;
|
| 3145 | case '5':
|
| 3146 | path.arcTo({24, 24}, 0, SkPath::kSmall_ArcSize, SkPath::kCW_Direction, {32, 56});
|
| 3147 | break;
|
| 3148 | case '6':
|
| 3149 | path.conicTo({56, 56}, {32, 56}, SK_ScalarRoot2Over2);
|
| 3150 | break;
|
| 3151 | }
|
| 3152 | canvas->drawPath(path, arcPaint);
|
| 3153 | }
|
| 3154 | }
|
| 3155 | #Example ##
|
| 3156 |
|
| 3157 |
|
| 3158 | #Method void arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo)
|
| 3159 |
|
| 3160 | Append Arc to Path. Arc added is part of ellipse
|
| 3161 | bounded by oval, from startAngle through sweepAngle. Both startAngle and
|
| 3162 | sweepAngle are measured in degrees, where zero degrees is aligned with the
|
| 3163 | positive x-axis, and positive sweeps extends Arc clockwise.
|
| 3164 |
|
| 3165 | arcTo adds Line connecting Path last Point to initial Arc Point if forceMoveTo
|
| 3166 | is false and Path is not empty. Otherwise, added Contour begins with first point
|
| 3167 | of Arc. Angles greater than -360 and less than 360 are treated modulo 360.
|
| 3168 |
|
| 3169 | #Param oval bounds of ellipse containing Arc. ##
|
| 3170 | #Param startAngle starting angle of Arc in degrees. ##
|
| 3171 | #Param sweepAngle sweep, in degrees. Positive is clockwise; treated modulo 360. ##
|
| 3172 | #Param forceMoveTo true to start a new contour with Arc. ##
|
| 3173 |
|
| 3174 | #Example
|
| 3175 | #Height 200
|
| 3176 | #Description
|
| 3177 | arcTo continues a previous contour when forceMoveTo is false and when Path
|
| 3178 | is not empty.
|
| 3179 | ##
|
| 3180 | void draw(SkCanvas* canvas) {
|
| 3181 | SkPaint paint;
|
| 3182 | SkPath path;
|
| 3183 | paint.setStyle(SkPaint::kStroke_Style);
|
| 3184 | paint.setStrokeWidth(4);
|
| 3185 | path.moveTo(0, 0);
|
| 3186 | path.arcTo({20, 20, 120, 120}, -90, 90, false);
|
| 3187 | canvas->drawPath(path, paint);
|
| 3188 | path.rewind();
|
| 3189 | path.arcTo({120, 20, 220, 120}, -90, 90, false);
|
| 3190 | canvas->drawPath(path, paint);
|
| 3191 | path.rewind();
|
| 3192 | path.moveTo(0, 0);
|
| 3193 | path.arcTo({20, 120, 120, 220}, -90, 90, true);
|
| 3194 | canvas->drawPath(path, paint);
|
| 3195 | }
|
| 3196 | ##
|
| 3197 |
|
| 3198 | #SeeAlso addArc SkCanvas::drawArc conicTo
|
| 3199 |
|
| 3200 | ##
|
| 3201 |
|
| 3202 | # ------------------------------------------------------------------------------
|
| 3203 |
|
| 3204 | #Method void arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius)
|
| 3205 |
|
| 3206 | Append Arc to Path, after appending Line if needed. Arc is implemented by Conic
|
| 3207 | weighted to describe part of Circle. Arc is contained by tangent from
|
| 3208 | last Path point (x0, y0) to (x1, y1), and tangent from (x1, y1) to (x2, y2). Arc
|
| 3209 | is part of Circle sized to radius, positioned so it touches both tangent lines.
|
| 3210 |
|
| 3211 | #ToDo allow example to hide source and not be exposed as fiddle ##
|
| 3212 |
|
| 3213 | #Example
|
| 3214 | #Height 226
|
| 3215 | void draw(SkCanvas* canvas) {
|
| 3216 | SkPaint tangentPaint;
|
| 3217 | tangentPaint.setAntiAlias(true);
|
| 3218 | SkPaint textPaint(tangentPaint);
|
| 3219 | tangentPaint.setStyle(SkPaint::kStroke_Style);
|
| 3220 | tangentPaint.setColor(SK_ColorGRAY);
|
| 3221 | SkPaint arcPaint(tangentPaint);
|
| 3222 | arcPaint.setStrokeWidth(5);
|
| 3223 | arcPaint.setColor(SK_ColorBLUE);
|
| 3224 | SkPath path;
|
| 3225 | SkPoint pts[] = { {56, 20}, {200, 20}, {90, 190} };
|
| 3226 | SkScalar radius = 50;
|
| 3227 | path.moveTo(pts[0]);
|
| 3228 | path.arcTo(pts[1], pts[2], radius);
|
| 3229 | canvas->drawLine(pts[0], pts[1], tangentPaint);
|
| 3230 | canvas->drawLine(pts[1], pts[2], tangentPaint);
|
| 3231 | SkPoint lastPt;
|
| 3232 | (void) path.getLastPt(&lastPt);
|
| 3233 | SkVector radial = pts[2] - pts[1];
|
| 3234 | radial.setLength(radius);
|
| 3235 | SkPoint center = { lastPt.fX - radial.fY, lastPt.fY + radial.fX };
|
| 3236 | canvas->drawCircle(center, radius, tangentPaint);
|
| 3237 | canvas->drawLine(lastPt, center, tangentPaint);
|
| 3238 | radial = pts[1] - pts[0];
|
| 3239 | radial.setLength(radius);
|
| 3240 | SkPoint arcStart = { center.fX + radial.fY, center.fY - radial.fX };
|
| 3241 | canvas->drawLine(center, arcStart, tangentPaint);
|
| 3242 | canvas->drawPath(path, arcPaint);
|
| 3243 | textPaint.setTextAlign(SkPaint::kRight_Align);
|
| 3244 | canvas->drawString("(x0, y0)", pts[0].fX - 5, pts[0].fY, textPaint);
|
| 3245 | textPaint.setTextAlign(SkPaint::kLeft_Align);
|
| 3246 | canvas->drawString("(x1, y1)", pts[1].fX + 5, pts[1].fY, textPaint);
|
| 3247 | textPaint.setTextAlign(SkPaint::kCenter_Align);
|
| 3248 | canvas->drawString("(x2, y2)", pts[2].fX, pts[2].fY + 15, textPaint);
|
| 3249 | textPaint.setTextAlign(SkPaint::kRight_Align);
|
| 3250 | canvas->drawString("radius", center.fX + 15, center.fY + 25, textPaint);
|
| 3251 | canvas->drawString("radius", center.fX - 3, center.fY - 16, textPaint);
|
| 3252 | }
|
| 3253 | ##
|
| 3254 |
|
| 3255 | If last Path Point does not start Arc, arcTo appends connecting Line to Path.
|
| 3256 | The length of Vector from (x1, y1) to (x2, y2) does not affect Arc.
|
| 3257 |
|
| 3258 | #Example
|
| 3259 | #Height 128
|
| 3260 | void draw(SkCanvas* canvas) {
|
| 3261 | SkPaint tangentPaint;
|
| 3262 | tangentPaint.setAntiAlias(true);
|
| 3263 | SkPaint textPaint(tangentPaint);
|
| 3264 | tangentPaint.setStyle(SkPaint::kStroke_Style);
|
| 3265 | tangentPaint.setColor(SK_ColorGRAY);
|
| 3266 | SkPaint arcPaint(tangentPaint);
|
| 3267 | arcPaint.setStrokeWidth(5);
|
| 3268 | arcPaint.setColor(SK_ColorBLUE);
|
| 3269 | SkPath path;
|
| 3270 | SkPoint pts[] = { {156, 20}, {200, 20}, {170, 50} };
|
| 3271 | SkScalar radius = 50;
|
| 3272 | path.moveTo(pts[0]);
|
| 3273 | path.arcTo(pts[1], pts[2], radius);
|
| 3274 | canvas->drawLine(pts[0], pts[1], tangentPaint);
|
| 3275 | canvas->drawLine(pts[1], pts[2], tangentPaint);
|
| 3276 | SkPoint lastPt;
|
| 3277 | (void) path.getLastPt(&lastPt);
|
| 3278 | SkVector radial = pts[2] - pts[1];
|
| 3279 | radial.setLength(radius);
|
| 3280 | SkPoint center = { lastPt.fX - radial.fY, lastPt.fY + radial.fX };
|
| 3281 | canvas->drawLine(lastPt, center, tangentPaint);
|
| 3282 | radial = pts[1] - pts[0];
|
| 3283 | radial.setLength(radius);
|
| 3284 | SkPoint arcStart = { center.fX + radial.fY, center.fY - radial.fX };
|
| 3285 | canvas->drawLine(center, arcStart, tangentPaint);
|
| 3286 | canvas->drawPath(path, arcPaint);
|
| 3287 | textPaint.setTextAlign(SkPaint::kCenter_Align);
|
| 3288 | canvas->drawString("(x0, y0)", pts[0].fX, pts[0].fY - 7, textPaint);
|
| 3289 | textPaint.setTextAlign(SkPaint::kLeft_Align);
|
| 3290 | canvas->drawString("(x1, y1)", pts[1].fX + 5, pts[1].fY, textPaint);
|
| 3291 | textPaint.setTextAlign(SkPaint::kCenter_Align);
|
| 3292 | canvas->drawString("(x2, y2)", pts[2].fX, pts[2].fY + 15, textPaint);
|
| 3293 | textPaint.setTextAlign(SkPaint::kRight_Align);
|
| 3294 | canvas->drawString("radius", center.fX + 15, center.fY + 25, textPaint);
|
| 3295 | canvas->drawString("radius", center.fX - 5, center.fY - 20, textPaint);
|
| 3296 | }
|
| 3297 | ##
|
| 3298 |
|
| 3299 | Arc sweep is always less than 180 degrees. If radius is zero, or if
|
| 3300 | tangents are nearly parallel, arcTo appends Line from last Path Point to (x1, y1).
|
| 3301 |
|
| 3302 | arcTo appends at most one Line and one Conic.
|
| 3303 | arcTo implements the functionality of PostScript_arct and HTML_Canvas_arcTo.
|
| 3304 |
|
| 3305 | #Param x1 x common to pair of tangents. ##
|
| 3306 | #Param y1 y common to pair of tangents. ##
|
| 3307 | #Param x2 x end of second tangent. ##
|
| 3308 | #Param y2 y end of second tangent. ##
|
| 3309 | #Param radius distance from Arc to Circle center. ##
|
| 3310 |
|
| 3311 | #Example
|
| 3312 | #Description
|
| 3313 | arcTo is represented by Line and circular Conic in Path.
|
| 3314 | ##
|
| 3315 | void draw(SkCanvas* canvas) {
|
| 3316 | SkPath path;
|
| 3317 | path.moveTo({156, 20});
|
| 3318 | path.arcTo(200, 20, 170, 50, 50);
|
| 3319 | SkPath::Iter iter(path, false);
|
| 3320 | SkPoint p[4];
|
| 3321 | SkPath::Verb verb;
|
| 3322 | while (SkPath::kDone_Verb != (verb = iter.next(p))) {
|
| 3323 | switch (verb) {
|
| 3324 | case SkPath::kMove_Verb:
|
| 3325 | SkDebugf("move to (%g,%g)\n", p[0].fX, p[0].fY);
|
| 3326 | break;
|
| 3327 | case SkPath::kLine_Verb:
|
| 3328 | SkDebugf("line (%g,%g),(%g,%g)\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY);
|
| 3329 | break;
|
| 3330 | case SkPath::kConic_Verb:
|
| 3331 | SkDebugf("conic (%g,%g),(%g,%g),(%g,%g) weight %g\n",
|
| 3332 | p[0].fX, p[0].fY, p[1].fX, p[1].fY, p[2].fX, p[2].fY, iter.conicWeight());
|
| 3333 | break;
|
| 3334 | default:
|
| 3335 | SkDebugf("unexpected verb\n");
|
| 3336 | }
|
| 3337 | }
|
| 3338 | }
|
| 3339 | #StdOut
|
| 3340 | move to (156,20)
|
| 3341 | line (156,20),(79.2893,20)
|
| 3342 | conic (79.2893,20),(200,20),(114.645,105.355) weight 0.382683
|
| 3343 | ##
|
| 3344 | ##
|
| 3345 |
|
| 3346 | #SeeAlso conicTo
|
| 3347 |
|
| 3348 | ##
|
| 3349 |
|
| 3350 | # ------------------------------------------------------------------------------
|
| 3351 |
|
| 3352 | #Method void arcTo(const SkPoint p1, const SkPoint p2, SkScalar radius)
|
| 3353 |
|
| 3354 | Append Arc to Path, after appending Line if needed. Arc is implemented by Conic
|
| 3355 | weighted to describe part of Circle. Arc is contained by tangent from
|
| 3356 | last Path point to p1, and tangent from p1 to p2. Arc
|
| 3357 | is part of Circle sized to radius, positioned so it touches both tangent lines.
|
| 3358 |
|
| 3359 | If last Path Point does not start Arc, arcTo appends connecting Line to Path.
|
| 3360 | The length of Vector from p1 to p2 does not affect Arc.
|
| 3361 |
|
| 3362 | Arc sweep is always less than 180 degrees. If radius is zero, or if
|
| 3363 | tangents are nearly parallel, arcTo appends Line from last Path Point to p1.
|
| 3364 |
|
| 3365 | arcTo appends at most one Line and one Conic.
|
| 3366 | arcTo implements the functionality of PostScript_arct and HTML_Canvas_arcTo.
|
| 3367 |
|
| 3368 | #Param p1 Point common to pair of tangents. ##
|
| 3369 | #Param p2 end of second tangent. ##
|
| 3370 | #Param radius distance from Arc to Circle center. ##
|
| 3371 |
|
| 3372 | #Example
|
| 3373 | #Description
|
| 3374 | Because tangent lines are parallel, arcTo appends line from last Path Point to
|
| 3375 | p1, but does not append a circular Conic.
|
| 3376 | ##
|
| 3377 | void draw(SkCanvas* canvas) {
|
| 3378 | SkPath path;
|
| 3379 | path.moveTo({156, 20});
|
| 3380 | path.arcTo({200, 20}, {170, 20}, 50);
|
| 3381 | SkPath::Iter iter(path, false);
|
| 3382 | SkPoint p[4];
|
| 3383 | SkPath::Verb verb;
|
| 3384 | while (SkPath::kDone_Verb != (verb = iter.next(p))) {
|
| 3385 | switch (verb) {
|
| 3386 | case SkPath::kMove_Verb:
|
| 3387 | SkDebugf("move to (%g,%g)\n", p[0].fX, p[0].fY);
|
| 3388 | break;
|
| 3389 | case SkPath::kLine_Verb:
|
| 3390 | SkDebugf("line (%g,%g),(%g,%g)\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY);
|
| 3391 | break;
|
| 3392 | case SkPath::kConic_Verb:
|
| 3393 | SkDebugf("conic (%g,%g),(%g,%g),(%g,%g) weight %g\n",
|
| 3394 | p[0].fX, p[0].fY, p[1].fX, p[1].fY, p[2].fX, p[2].fY, iter.conicWeight());
|
| 3395 | break;
|
| 3396 | default:
|
| 3397 | SkDebugf("unexpected verb\n");
|
| 3398 | }
|
| 3399 | }
|
| 3400 | }
|
| 3401 | #StdOut
|
| 3402 | move to (156,20)
|
| 3403 | line (156,20),(200,20)
|
| 3404 | ##
|
| 3405 | ##
|
| 3406 |
|
| 3407 | #SeeAlso conicTo
|
| 3408 |
|
| 3409 | ##
|
| 3410 |
|
| 3411 | # ------------------------------------------------------------------------------
|
| 3412 |
|
| 3413 | #Enum ArcSize
|
| 3414 |
|
| 3415 | #Code
|
| 3416 | enum ArcSize {
|
| 3417 | kSmall_ArcSize
|
| 3418 | kLarge_ArcSize
|
| 3419 | };
|
| 3420 | ##
|
| 3421 |
|
| 3422 | Four Oval parts with radii (rx, ry) start at last Path Point and ends at (x, y).
|
| 3423 | ArcSize and Direction select one of the four Oval parts.
|
| 3424 |
|
| 3425 | #Const kSmall_ArcSize 0
|
| 3426 | Smaller of Arc pair.
|
| 3427 | ##
|
| 3428 | #Const kLarge_ArcSize 1
|
| 3429 | Larger of Arc pair.
|
| 3430 | ##
|
| 3431 |
|
| 3432 | #Example
|
| 3433 | #Height 160
|
| 3434 | #Description
|
| 3435 | Arc begins at top of Oval pair and ends at bottom. Arc can take four routes to get there.
|
| 3436 | Two routes are large, and two routes are counterclockwise. The one route both large
|
| 3437 | and counterclockwise is blue.
|
| 3438 | ##
|
| 3439 | void draw(SkCanvas* canvas) {
|
| 3440 | SkPaint paint;
|
| 3441 | paint.setAntiAlias(true);
|
| 3442 | paint.setStyle(SkPaint::kStroke_Style);
|
| 3443 | for (auto sweep: { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
|
| 3444 | for (auto arcSize : { SkPath::kSmall_ArcSize, SkPath::kLarge_ArcSize } ) {
|
| 3445 | SkPath path;
|
| 3446 | path.moveTo({120, 50});
|
| 3447 | path.arcTo(70, 40, 30, arcSize, sweep, 156, 100);
|
| 3448 | if (SkPath::kCCW_Direction == sweep && SkPath::kLarge_ArcSize == arcSize) {
|
| 3449 | paint.setColor(SK_ColorBLUE);
|
| 3450 | paint.setStrokeWidth(3);
|
| 3451 | }
|
| 3452 | canvas->drawPath(path, paint);
|
| 3453 | }
|
| 3454 | }
|
| 3455 | }
|
| 3456 | ##
|
| 3457 |
|
| 3458 | #SeeAlso arcTo Direction
|
| 3459 |
|
| 3460 | ##
|
| 3461 |
|
| 3462 | # ------------------------------------------------------------------------------
|
| 3463 |
|
| 3464 | #Method void arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc,
|
| 3465 | Direction sweep, SkScalar x, SkScalar y)
|
| 3466 |
|
| 3467 | Append Arc to Path. Arc is implemented by one or more Conic weighted to describe part of Oval
|
| 3468 | with radii (rx, ry) rotated by xAxisRotate degrees. Arc curves from last Path Point to (x, y),
|
| 3469 | choosing one of four possible routes: clockwise or counterclockwise, and smaller or larger.
|
| 3470 |
|
| 3471 | Arc sweep is always less than 360 degrees. arcTo appends Line to (x, y) if either radii are zero,
|
| 3472 | or if last Path Point equals (x, y). arcTo scales radii (rx, ry) to fit last Path Point and
|
| 3473 | (x, y) if both are greater than zero but too small.
|
| 3474 |
|
| 3475 | arcTo appends up to four Conic curves.
|
| 3476 | arcTo implements the functionatlity of SVG_Arc, although SVG sweep-flag value is
|
| 3477 | opposite the integer value of sweep; SVG sweep-flag uses 1 for clockwise, while kCW_Direction
|
| 3478 | cast to int is zero.
|
| 3479 |
|
| 3480 | #Param rx radius in x before x-axis rotation. ##
|
| 3481 | #Param ry radius in y before x-axis rotation. ##
|
| 3482 | #Param xAxisRotate x-axis rotation in degrees; positve values are clockwise. ##
|
| 3483 | #Param largeArc chooses smaller or larger Arc. ##
|
| 3484 | #Param sweep chooses clockwise or counterclockwise Arc. ##
|
| 3485 | #Param x end of Arc. ##
|
| 3486 | #Param y end of Arc. ##
|
| 3487 |
|
| 3488 | #Example
|
| 3489 | #Height 160
|
| 3490 | void draw(SkCanvas* canvas) {
|
| 3491 | SkPaint paint;
|
| 3492 | paint.setAntiAlias(true);
|
| 3493 | paint.setStyle(SkPaint::kStroke_Style);
|
| 3494 | for (auto sweep: { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
|
| 3495 | for (auto arcSize : { SkPath::kSmall_ArcSize, SkPath::kLarge_ArcSize } ) {
|
| 3496 | SkPath path;
|
| 3497 | path.moveTo({120, 50});
|
| 3498 | path.arcTo(70, 40, 30, arcSize, sweep, 120.1, 50);
|
| 3499 | if (SkPath::kCCW_Direction == sweep && SkPath::kLarge_ArcSize == arcSize) {
|
| 3500 | paint.setColor(SK_ColorBLUE);
|
| 3501 | paint.setStrokeWidth(3);
|
| 3502 | }
|
| 3503 | canvas->drawPath(path, paint);
|
| 3504 | }
|
| 3505 | }
|
| 3506 | }
|
| 3507 | ##
|
| 3508 |
|
| 3509 | #SeeAlso rArcTo ArcSize Direction
|
| 3510 |
|
| 3511 | ##
|
| 3512 |
|
| 3513 | # ------------------------------------------------------------------------------
|
| 3514 |
|
| 3515 | #Method void arcTo(const SkPoint r, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep,
|
| 3516 | const SkPoint xy)
|
| 3517 |
|
| 3518 | Append Arc to Path. Arc is implemented by one or more Conic weighted to describe part of Oval
|
| 3519 | with radii (r.fX, r.fY) rotated by xAxisRotate degrees. Arc curves from last Path Point to
|
| 3520 | (xy.fX, xy.fY), choosing one of four possible routes: clockwise or counterclockwise,
|
| 3521 | and smaller or larger.
|
| 3522 |
|
| 3523 | Arc sweep is always less than 360 degrees. arcTo appends Line to xy if either radii are zero,
|
| 3524 | or if last Path Point equals (x, y). arcTo scales radii r to fit last Path Point and
|
| 3525 | xy if both are greater than zero but too small.
|
| 3526 |
|
| 3527 | arcTo appends up to four Conic curves.
|
| 3528 | arcTo implements the functionatlity of SVG_Arc, although SVG sweep-flag value is
|
| 3529 | opposite the integer value of sweep; SVG sweep-flag uses 1 for clockwise, while kCW_Direction
|
| 3530 | cast to int is zero.
|
| 3531 |
|
| 3532 | #Param r radii in x and y before x-axis rotation. ##
|
| 3533 | #Param xAxisRotate x-axis rotation in degrees; positve values are clockwise. ##
|
| 3534 | #Param largeArc chooses smaller or larger Arc. ##
|
| 3535 | #Param sweep chooses clockwise or counterclockwise Arc. ##
|
| 3536 | #Param xy end of Arc. ##
|
| 3537 |
|
| 3538 | #Example
|
| 3539 | #Height 108
|
| 3540 | void draw(SkCanvas* canvas) {
|
| 3541 | SkPaint paint;
|
| 3542 | SkPath path;
|
| 3543 | const SkPoint starts[] = {{20, 20}, {120, 20}, {70, 60}};
|
| 3544 | for (auto start : starts) {
|
| 3545 | path.moveTo(start.fX, start.fY);
|
| 3546 | path.rArcTo(20, 20, 0, SkPath::kSmall_ArcSize, SkPath::kCCW_Direction, 60, 0);
|
| 3547 | }
|
| 3548 | canvas->drawPath(path, paint);
|
| 3549 | }
|
| 3550 | ##
|
| 3551 |
|
| 3552 | #SeeAlso rArcTo ArcSize Direction
|
| 3553 |
|
| 3554 | ##
|
| 3555 |
|
| 3556 | # ------------------------------------------------------------------------------
|
| 3557 |
|
| 3558 | #Method void rArcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc,
|
| 3559 | Direction sweep, SkScalar dx, SkScalar dy)
|
| 3560 |
|
| 3561 | Append Arc to Path, relative to last Path Point. Arc is implemented by one or
|
| 3562 | more Conic, weighted to describe part of Oval with radii (r.fX, r.fY) rotated by
|
| 3563 | xAxisRotate degrees. Arc curves from last Path Point (x0, y0) to
|
| 3564 | (x0 + dx, y0 + dy), choosing one of four possible routes: clockwise or
|
| 3565 | counterclockwise, and smaller or larger. If Path is empty, the start Arc Point
|
| 3566 | is (0, 0).
|
| 3567 |
|
| 3568 | Arc sweep is always less than 360 degrees. arcTo appends Line to xy if either
|
| 3569 | radii are zero, or if last Path Point equals (x, y). arcTo scales radii r to fit
|
| 3570 | last Path Point and xy if both are greater than zero but too small.
|
| 3571 |
|
| 3572 | arcTo appends up to four Conic curves.
|
| 3573 | arcTo implements the functionatlity of SVG_Arc, although SVG sweep-flag value is
|
| 3574 | opposite the integer value of sweep; SVG sweep-flag uses 1 for clockwise, while
|
| 3575 | kCW_Direction cast to int is zero.
|
| 3576 |
|
| 3577 | #Param rx radius in x before x-axis rotation. ##
|
| 3578 | #Param ry radius in y before x-axis rotation. ##
|
| 3579 | #Param xAxisRotate x-axis rotation in degrees; positve values are clockwise. ##
|
| 3580 | #Param largeArc chooses smaller or larger Arc. ##
|
| 3581 | #Param sweep chooses clockwise or counterclockwise Arc. ##
|
| 3582 | #Param dx x offset end of Arc from last Path Point. ##
|
| 3583 | #Param dy y offset end of Arc from last Path Point. ##
|
| 3584 |
|
| 3585 | #Example
|
| 3586 | #Height 108
|
| 3587 | void draw(SkCanvas* canvas) {
|
| 3588 | SkPaint paint;
|
| 3589 | SkPath path;
|
| 3590 | const SkPoint starts[] = {{20, 20}, {120, 20}, {70, 60}};
|
| 3591 | for (auto start : starts) {
|
| 3592 | path.moveTo(start.fX, start.fY);
|
| 3593 | path.rArcTo(20, 20, 0, SkPath::kSmall_ArcSize, SkPath::kCCW_Direction, 60, 0);
|
| 3594 | }
|
| 3595 | canvas->drawPath(path, paint);
|
| 3596 | }
|
| 3597 | ##
|
| 3598 |
|
| 3599 | #SeeAlso arcTo ArcSize Direction
|
| 3600 |
|
| 3601 | ##
|
| 3602 |
|
| 3603 | #Topic Arc ##
|
| 3604 |
|
| 3605 | # ------------------------------------------------------------------------------
|
| 3606 |
|
| 3607 | #Method void close()
|
| 3608 |
|
| 3609 | Append kClose_Verb to Path. A closed Contour connects the first and last Point
|
| 3610 | with Line, forming a continous loop. Open and closed Contour draw the same
|
| 3611 | with SkPaint::kFill_Style. With SkPaint::kStroke_Style, open Contour draws
|
| 3612 | Paint_Stroke_Cap at Contour start and end; closed Contour draws
|
| 3613 | Paint_Stroke_Join at Contour start and end.
|
| 3614 |
|
| 3615 | close() has no effect if Path is empty or last Path Verb is kClose_Verb.
|
| 3616 |
|
| 3617 | #Example
|
| 3618 | void draw(SkCanvas* canvas) {
|
| 3619 | SkPaint paint;
|
| 3620 | paint.setStrokeWidth(15);
|
| 3621 | paint.setStrokeCap(SkPaint::kRound_Cap);
|
| 3622 | SkPath path;
|
| 3623 | const SkPoint points[] = {{20, 20}, {70, 20}, {40, 90}};
|
| 3624 | path.addPoly(points, SK_ARRAY_COUNT(points), false);
|
| 3625 | for (int loop = 0; loop < 2; ++loop) {
|
| 3626 | for (auto style : {SkPaint::kStroke_Style, SkPaint::kFill_Style,
|
| 3627 | SkPaint::kStrokeAndFill_Style} ) {
|
| 3628 | paint.setStyle(style);
|
| 3629 | canvas->drawPath(path, paint);
|
| 3630 | canvas->translate(85, 0);
|
| 3631 | }
|
| 3632 | path.close();
|
| 3633 | canvas->translate(-255, 128);
|
| 3634 | }
|
| 3635 | }
|
| 3636 | ##
|
| 3637 |
|
| 3638 | #SeeAlso
|
| 3639 |
|
| 3640 | ##
|
| 3641 |
|
| 3642 | # ------------------------------------------------------------------------------
|
| 3643 |
|
| 3644 | #Method static bool IsInverseFillType(FillType fill)
|
| 3645 |
|
| 3646 | Returns true if fill is inverted and Path with fill represents area outside
|
| 3647 | of its geometric bounds.
|
| 3648 |
|
| 3649 | #Table
|
| 3650 | #Legend
|
| 3651 | # FillType # is inverse ##
|
| 3652 | ##
|
| 3653 | # kWinding_FillType # false ##
|
| 3654 | # kEvenOdd_FillType # false ##
|
| 3655 | # kInverseWinding_FillType # true ##
|
| 3656 | # kInverseEvenOdd_FillType # true ##
|
| 3657 | ##
|
| 3658 |
|
| 3659 | #Param fill one of: kWinding_FillType, kEvenOdd_FillType,
|
| 3660 | kInverseWinding_FillType, kInverseEvenOdd_FillType.
|
| 3661 | ##
|
| 3662 |
|
| 3663 | #Return true if Path fills outside its bounds. ##
|
| 3664 |
|
| 3665 | #Example
|
| 3666 | #Function
|
| 3667 | #define nameValue(fill) { SkPath::fill, #fill }
|
| 3668 |
|
| 3669 | ##
|
| 3670 | void draw(SkCanvas* canvas) {
|
| 3671 | struct {
|
| 3672 | SkPath::FillType fill;
|
| 3673 | const char* name;
|
| 3674 | } fills[] = {
|
| 3675 | nameValue(kWinding_FillType),
|
| 3676 | nameValue(kEvenOdd_FillType),
|
| 3677 | nameValue(kInverseWinding_FillType),
|
| 3678 | nameValue(kInverseEvenOdd_FillType),
|
| 3679 | };
|
| 3680 | for (auto fill: fills ) {
|
| 3681 | SkDebugf("IsInverseFillType(%s) == %s\n", fill.name, SkPath::IsInverseFillType(fill.fill) ?
|
| 3682 | "true" : "false");
|
| 3683 | }
|
| 3684 | }
|
| 3685 | #StdOut
|
| 3686 | IsInverseFillType(kWinding_FillType) == false
|
| 3687 | IsInverseFillType(kEvenOdd_FillType) == false
|
| 3688 | IsInverseFillType(kInverseWinding_FillType) == true
|
| 3689 | IsInverseFillType(kInverseEvenOdd_FillType) == true
|
| 3690 | ##
|
| 3691 | ##
|
| 3692 |
|
| 3693 | #SeeAlso FillType getFillType setFillType ConvertToNonInverseFillType
|
| 3694 |
|
| 3695 | ##
|
| 3696 |
|
| 3697 | # ------------------------------------------------------------------------------
|
| 3698 |
|
| 3699 | #Method static FillType ConvertToNonInverseFillType(FillType fill)
|
| 3700 |
|
| 3701 | Returns equivalent Fill_Type representing Path fill inside its bounds.
|
| 3702 | .
|
| 3703 |
|
| 3704 | #Table
|
| 3705 | #Legend
|
| 3706 | # FillType # inside FillType ##
|
| 3707 | ##
|
| 3708 | # kWinding_FillType # kWinding_FillType ##
|
| 3709 | # kEvenOdd_FillType # kEvenOdd_FillType ##
|
| 3710 | # kInverseWinding_FillType # kWinding_FillType ##
|
| 3711 | # kInverseEvenOdd_FillType # kEvenOdd_FillType ##
|
| 3712 | ##
|
| 3713 |
|
| 3714 | #Param fill one of: kWinding_FillType, kEvenOdd_FillType,
|
| 3715 | kInverseWinding_FillType, kInverseEvenOdd_FillType.
|
| 3716 | ##
|
| 3717 |
|
| 3718 | #Return fill, or kWinding_FillType or kEvenOdd_FillType if fill is inverted. ##
|
| 3719 |
|
| 3720 | #Example
|
| 3721 | #Function
|
| 3722 | #define nameValue(fill) { SkPath::fill, #fill }
|
| 3723 |
|
| 3724 | ##
|
| 3725 | void draw(SkCanvas* canvas) {
|
| 3726 | struct {
|
| 3727 | SkPath::FillType fill;
|
| 3728 | const char* name;
|
| 3729 | } fills[] = {
|
| 3730 | nameValue(kWinding_FillType),
|
| 3731 | nameValue(kEvenOdd_FillType),
|
| 3732 | nameValue(kInverseWinding_FillType),
|
| 3733 | nameValue(kInverseEvenOdd_FillType),
|
| 3734 | };
|
| 3735 | for (unsigned i = 0; i < SK_ARRAY_COUNT(fills); ++i) {
|
| 3736 | if (fills[i].fill != (SkPath::FillType) i) {
|
| 3737 | SkDebugf("fills array order does not match FillType enum order");
|
| 3738 | break;
|
| 3739 | }
|
| 3740 | SkDebugf("ConvertToNonInverseFillType(%s) == %s\n", fills[i].name,
|
| 3741 | fills[(int) SkPath::ConvertToNonInverseFillType(fills[i].fill)].name);
|
| 3742 | }
|
| 3743 | }
|
| 3744 | #StdOut
|
| 3745 | ConvertToNonInverseFillType(kWinding_FillType) == kWinding_FillType
|
| 3746 | ConvertToNonInverseFillType(kEvenOdd_FillType) == kEvenOdd_FillType
|
| 3747 | ConvertToNonInverseFillType(kInverseWinding_FillType) == kWinding_FillType
|
| 3748 | ConvertToNonInverseFillType(kInverseEvenOdd_FillType) == kEvenOdd_FillType
|
| 3749 | ##
|
| 3750 | ##
|
| 3751 |
|
| 3752 | #SeeAlso FillType getFillType setFillType IsInverseFillType
|
| 3753 |
|
| 3754 | ##
|
| 3755 |
|
| 3756 | # ------------------------------------------------------------------------------
|
| 3757 |
|
| 3758 | #Method static int ConvertConicToQuads(const SkPoint& p0, const SkPoint& p1, const SkPoint& p2,
|
| 3759 | SkScalar w, SkPoint pts[], int pow2)
|
| 3760 |
|
| 3761 | Approximates Conic with Quad array. Conic is constructed from start Point p0,
|
| 3762 | control Point p1, end Point p2, and weight w.
|
| 3763 | Quad array is stored in pts; this storage is supplied by caller.
|
| 3764 | Maximum Quad count is 2 to the pow2.
|
| 3765 | Every third point in array shares last Point of previous Quad and first Point of
|
| 3766 | next Quad. Maximum pts storage size is given by:
|
| 3767 | #Formula
|
| 3768 | (1 + 2 * (1 << pow2)) * sizeof(SkPoint)
|
| 3769 | ##
|
| 3770 | ConvertConicToQuads returns Quad count used the approximation, which may be smaller
|
| 3771 | than the number requested.
|
| 3772 |
|
| 3773 | Conic_Weight determines the amount of influence Conic control point has on the curve.
|
| 3774 | w less than one represents an elliptical section. w greater than one represents
|
| 3775 | a hyperbolic section. w equal to one represents a parabolic section.
|
| 3776 |
|
| 3777 | Two Quad curves are sufficient to approximate an elliptical Conic with a sweep
|
| 3778 | of up to 90 degrees; in this case, set pow2 to one.
|
| 3779 |
|
| 3780 | #Param p0 Conic start Point. ##
|
| 3781 | #Param p1 Conic control Point. ##
|
| 3782 | #Param p2 Conic end Point. ##
|
| 3783 | #Param w Conic weight. ##
|
| 3784 | #Param pts storage for Quad array. ##
|
| 3785 | #Param pow2 Quad count, as power of two, normally 0 to 5 (1 to 32 Quad curves). ##
|
| 3786 |
|
| 3787 | #Return Number of Quad curves written to pts. ##
|
| 3788 |
|
| 3789 | #Example
|
| 3790 | #Description
|
| 3791 | A pair of Quad curves are drawn in red on top of the elliptical Conic curve in black.
|
| 3792 | The middle curve is nearly circular. The top-right curve is parabolic, which can
|
| 3793 | be drawn exactly with a single Quad.
|
| 3794 | ##
|
| 3795 | void draw(SkCanvas* canvas) {
|
| 3796 | SkPaint conicPaint;
|
| 3797 | conicPaint.setAntiAlias(true);
|
| 3798 | conicPaint.setStyle(SkPaint::kStroke_Style);
|
| 3799 | SkPaint quadPaint(conicPaint);
|
| 3800 | quadPaint.setColor(SK_ColorRED);
|
| 3801 | SkPoint conic[] = { {20, 170}, {80, 170}, {80, 230} };
|
| 3802 | for (auto weight : { .25f, .5f, .707f, .85f, 1.f } ) {
|
| 3803 | SkPoint quads[5];
|
| 3804 | SkPath::ConvertConicToQuads(conic[0], conic[1], conic[2], weight, quads, 1);
|
| 3805 | SkPath path;
|
| 3806 | path.moveTo(conic[0]);
|
| 3807 | path.conicTo(conic[1], conic[2], weight);
|
| 3808 | canvas->drawPath(path, conicPaint);
|
| 3809 | path.rewind();
|
| 3810 | path.moveTo(quads[0]);
|
| 3811 | path.quadTo(quads[1], quads[2]);
|
| 3812 | path.quadTo(quads[3], quads[4]);
|
| 3813 | canvas->drawPath(path, quadPaint);
|
| 3814 | canvas->translate(50, -50);
|
| 3815 | }
|
| 3816 | }
|
| 3817 | ##
|
| 3818 |
|
| 3819 | #SeeAlso Conic Quad
|
| 3820 |
|
| 3821 | ##
|
| 3822 |
|
| 3823 | # ------------------------------------------------------------------------------
|
| 3824 |
|
| 3825 | #Method bool isRect(SkRect* rect, bool* isClosed = NULL, Direction* direction = NULL) const
|
| 3826 |
|
| 3827 | Returns true if Path is eqivalent to Rect when filled.
|
| 3828 | If isRect returns false: rect, isClosed, and direction are unchanged.
|
| 3829 | If isRect returns true: rect, isClosed, and direction are written to if not nullptr.
|
| 3830 |
|
| 3831 | rect may be smaller than the Path bounds. Path bounds may include kMove_Verb points
|
| 3832 | that do not alter the area drawn by the returned rect.
|
| 3833 |
|
| 3834 | #Param rect storage for bounds of Rect; may be nullptr. ##
|
| 3835 | #Param isClosed storage set to true if Path is closed; may be nullptr ##
|
| 3836 | #Param direction storage set to Rect direction; may be nullptr. ##
|
| 3837 |
|
| 3838 | #Return true if Path contains Rect. ##
|
| 3839 |
|
| 3840 | #Example
|
| 3841 | #Description
|
| 3842 | After addRect, isRect returns true. Following moveTo permits isRect to return true, but
|
| 3843 | following lineTo does not. addPoly returns true even though rect is not closed, and one
|
| 3844 | side of rect is made up of consecutive line segments.
|
| 3845 | ##
|
| 3846 | void draw(SkCanvas* canvas) {
|
| 3847 | auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
| 3848 | SkRect rect;
|
| 3849 | SkPath::Direction direction;
|
| 3850 | bool isClosed;
|
| 3851 | path.isRect(&rect, &isClosed, &direction) ?
|
| 3852 | SkDebugf("%s is rect (%g, %g, %g, %g); is %s" "closed; direction %s\n", prefix,
|
| 3853 | rect.fLeft, rect.fTop, rect.fRight, rect.fBottom, isClosed ? "" : "not ",
|
| 3854 | SkPath::kCW_Direction == direction ? "CW" : "CCW") :
|
| 3855 | SkDebugf("%s is not rect\n", prefix);
|
| 3856 | };
|
| 3857 | SkPath path;
|
| 3858 | debugster("empty", path);
|
| 3859 | path.addRect({10, 20, 30, 40});
|
| 3860 | debugster("addRect", path);
|
| 3861 | path.moveTo(60, 70);
|
| 3862 | debugster("moveTo", path);
|
| 3863 | path.lineTo(60, 70);
|
| 3864 | debugster("lineTo", path);
|
| 3865 | path.reset();
|
| 3866 | const SkPoint pts[] = { {0, 0}, {0, 80}, {80, 80}, {80, 0}, {40, 0}, {20, 0} };
|
| 3867 | path.addPoly(pts, SK_ARRAY_COUNT(pts), false);
|
| 3868 | debugster("addPoly", path);
|
| 3869 | }
|
| 3870 | #StdOut
|
| 3871 | empty is not rect
|
| 3872 | addRect is rect (10, 20, 30, 40); is closed; direction CW
|
| 3873 | moveTo is rect (10, 20, 30, 40); is closed; direction CW
|
| 3874 | lineTo is not rect
|
| 3875 | addPoly is rect (0, 0, 80, 80); is not closed; direction CCW
|
| 3876 | ##
|
| 3877 | ##
|
| 3878 |
|
| 3879 | #SeeAlso computeTightBounds conservativelyContainsRect getBounds isConvex isLastContourClosed isNestedFillRects
|
| 3880 |
|
| 3881 | ##
|
| 3882 |
|
| 3883 | # ------------------------------------------------------------------------------
|
| 3884 |
|
| 3885 | #Method bool isNestedFillRects(SkRect rect[2], Direction dirs[2] = NULL) const
|
| 3886 |
|
| 3887 | Returns true if Path is equivalent to nested Rect pair when filled.
|
| 3888 | If isNestedFillRects returns false, rect and dirs are unchanged.
|
| 3889 | If isNestedFillRects returns true, rect and dirs are written to if not nullptr:
|
| 3890 | setting rect[0] to outer Rect, and rect[1] to inner Rect;
|
| 3891 | setting dirs[0] to Direction of outer Rect, and dirs[1] to Direction of inner
|
| 3892 | Rect.
|
| 3893 |
|
| 3894 | #Param rect storage for Rect pair; may be nullptr. ##
|
| 3895 | #Param dirs storage for Direction pair; may be nullptr. ##
|
| 3896 |
|
| 3897 | #Return true if Path contains nested Rect pair. ##
|
| 3898 |
|
| 3899 | #Example
|
| 3900 | void draw(SkCanvas* canvas) {
|
| 3901 | SkPaint paint;
|
| 3902 | paint.setStyle(SkPaint::kStroke_Style);
|
| 3903 | paint.setStrokeWidth(5);
|
| 3904 | SkPath path;
|
| 3905 | path.addRect({10, 20, 30, 40});
|
| 3906 | paint.getFillPath(path, &path);
|
| 3907 | SkRect rects[2];
|
| 3908 | SkPath::Direction directions[2];
|
| 3909 | if (path.isNestedFillRects(rects, directions)) {
|
| 3910 | for (int i = 0; i < 2; ++i) {
|
| 3911 | SkDebugf("%s (%g, %g, %g, %g); direction %s\n", i ? "inner" : "outer",
|
| 3912 | rects[i].fLeft, rects[i].fTop, rects[i].fRight, rects[i].fBottom,
|
| 3913 | SkPath::kCW_Direction == directions[i] ? "CW" : "CCW");
|
| 3914 | }
|
| 3915 | } else {
|
| 3916 | SkDebugf("is not nested rectangles\n");
|
| 3917 | }
|
| 3918 | }
|
| 3919 | #StdOut
|
| 3920 | outer (7.5, 17.5, 32.5, 42.5); direction CW
|
| 3921 | inner (12.5, 22.5, 27.5, 37.5); direction CCW
|
| 3922 | ##
|
| 3923 | ##
|
| 3924 |
|
| 3925 | #SeeAlso computeTightBounds conservativelyContainsRect getBounds isConvex isLastContourClosed isRect
|
| 3926 |
|
| 3927 | ##
|
| 3928 |
|
| 3929 | # ------------------------------------------------------------------------------
|
| 3930 |
|
| 3931 | #Method void addRect(const SkRect& rect, Direction dir = kCW_Direction)
|
| 3932 |
|
| 3933 | Add Rect to Path, appending kMove_Verb, three kLine_Verb, and kClose_Verb,
|
| 3934 | starting with top-left corner of Rect; followed by top-right, bottom-right,
|
| 3935 | and bottom-left if dir is kCW_Direction; or followed by bottom-left,
|
| 3936 | bottom-right, and top-right if dir is kCCW_Direction.
|
| 3937 |
|
| 3938 | #Param rect Rect to add as a closed contour. ##
|
| 3939 | #Param dir Direction to wind added contour. ##
|
| 3940 |
|
| 3941 | #Example
|
| 3942 | #Description
|
| 3943 | The left Rect dashes starting at the top-left corner, to the right.
|
| 3944 | The right Rect dashes starting at the top-left corner, towards the bottom.
|
| 3945 | ##
|
| 3946 | #Height 128
|
| 3947 | void draw(SkCanvas* canvas) {
|
| 3948 | SkPaint paint;
|
| 3949 | paint.setStrokeWidth(15);
|
| 3950 | paint.setStrokeCap(SkPaint::kSquare_Cap);
|
| 3951 | float intervals[] = { 5, 21.75f };
|
| 3952 | paint.setStyle(SkPaint::kStroke_Style);
|
| 3953 | paint.setPathEffect(SkDashPathEffect::Make(intervals, SK_ARRAY_COUNT(intervals), 0));
|
| 3954 | SkPath path;
|
| 3955 | path.addRect({20, 20, 100, 100}, SkPath::kCW_Direction);
|
| 3956 | canvas->drawPath(path, paint);
|
| 3957 | path.rewind();
|
| 3958 | path.addRect({140, 20, 220, 100}, SkPath::kCCW_Direction);
|
| 3959 | canvas->drawPath(path, paint);
|
| 3960 | }
|
| 3961 | ##
|
| 3962 |
|
| 3963 | #SeeAlso SkCanvas::drawRect Direction
|
| 3964 |
|
| 3965 | ##
|
| 3966 |
|
| 3967 | # ------------------------------------------------------------------------------
|
| 3968 |
|
| 3969 | #Method void addRect(const SkRect& rect, Direction dir, unsigned start)
|
| 3970 |
|
| 3971 | Add Rect to Path, appending kMove_Verb, three kLine_Verb, and kClose_Verb.
|
| 3972 | If dir is kCW_Direction, Rect corners are added clockwise; if dir is
|
| 3973 | kCCW_Direction, Rect corners are added counterclockwise.
|
| 3974 | start determines the first corner added.
|
| 3975 |
|
| 3976 | #Table
|
| 3977 | #Legend
|
| 3978 | # start # first corner ##
|
| 3979 | #Legend ##
|
| 3980 | # 0 # top-left ##
|
| 3981 | # 1 # top-right ##
|
| 3982 | # 2 # bottom-right ##
|
| 3983 | # 3 # bottom-left ##
|
| 3984 | #Table ##
|
| 3985 |
|
| 3986 | #Param rect Rect to add as a closed contour. ##
|
| 3987 | #Param dir Direction to wind added contour. ##
|
| 3988 | #Param start Initial corner of Rect to add. ##
|
| 3989 |
|
| 3990 | #Example
|
| 3991 | #Height 128
|
| 3992 | #Description
|
| 3993 | The arrow is just after the initial corner and points towards the next
|
| 3994 | corner appended to Path.
|
| 3995 | ##
|
| 3996 | void draw(SkCanvas* canvas) {
|
| 3997 | const SkPoint arrow[] = { {5, -5}, {15, -5}, {20, 0}, {15, 5}, {5, 5}, {10, 0} };
|
| 3998 | const SkRect rect = {10, 10, 54, 54};
|
| 3999 | SkPaint rectPaint;
|
| 4000 | rectPaint.setAntiAlias(true);
|
| 4001 | rectPaint.setStyle(SkPaint::kStroke_Style);
|
| 4002 | SkPaint arrowPaint(rectPaint);
|
| 4003 | SkPath arrowPath;
|
| 4004 | arrowPath.addPoly(arrow, SK_ARRAY_COUNT(arrow), true);
|
| 4005 | arrowPaint.setPathEffect(SkPath1DPathEffect::Make(arrowPath, 176, 0,
|
| 4006 | SkPath1DPathEffect::kRotate_Style));
|
| 4007 | for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
|
| 4008 | for (unsigned start : { 0, 1, 2, 3 } ) {
|
| 4009 | SkPath path;
|
| 4010 | path.addRect(rect, direction, start);
|
| 4011 | canvas->drawPath(path, rectPaint);
|
| 4012 | canvas->drawPath(path, arrowPaint);
|
| 4013 | canvas->translate(64, 0);
|
| 4014 | }
|
| 4015 | canvas->translate(-256, 64);
|
| 4016 | }
|
| 4017 | }
|
| 4018 | ##
|
| 4019 |
|
| 4020 | #SeeAlso SkCanvas::drawRect Direction
|
| 4021 |
|
| 4022 | ##
|
| 4023 |
|
| 4024 | # ------------------------------------------------------------------------------
|
| 4025 |
|
| 4026 | #Method void addRect(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom,
|
| 4027 | Direction dir = kCW_Direction)
|
| 4028 |
|
| 4029 | Add Rect (left, top, right, bottom) to Path,
|
| 4030 | appending kMove_Verb, three kLine_Verb, and kClose_Verb,
|
| 4031 | starting with top-left corner of Rect; followed by top-right, bottom-right,
|
| 4032 | and bottom-left if dir is kCW_Direction; or followed by bottom-left,
|
| 4033 | bottom-right, and top-right if dir is kCCW_Direction.
|
| 4034 |
|
| 4035 | #Param left smaller x of Rect. ##
|
| 4036 | #Param top smaller y of Rect. ##
|
| 4037 | #Param right larger x of Rect. ##
|
| 4038 | #Param bottom larger y of Rect. ##
|
| 4039 | #Param dir Direction to wind added contour. ##
|
| 4040 |
|
| 4041 | #Example
|
| 4042 | #Description
|
| 4043 | The left Rect dashes start at the top-left corner, and continue to the right.
|
| 4044 | The right Rect dashes start at the top-left corner, and continue down.
|
| 4045 | ##
|
| 4046 | #Height 128
|
| 4047 | void draw(SkCanvas* canvas) {
|
| 4048 | SkPaint paint;
|
| 4049 | paint.setStrokeWidth(15);
|
| 4050 | paint.setStrokeCap(SkPaint::kSquare_Cap);
|
| 4051 | float intervals[] = { 5, 21.75f };
|
| 4052 | paint.setStyle(SkPaint::kStroke_Style);
|
| 4053 | paint.setPathEffect(SkDashPathEffect::Make(intervals, SK_ARRAY_COUNT(intervals), 0));
|
| 4054 | for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
|
| 4055 | SkPath path;
|
| 4056 | path.addRect(20, 20, 100, 100, direction);
|
| 4057 | canvas->drawPath(path, paint);
|
| 4058 | canvas->translate(128, 0);
|
| 4059 | }
|
| 4060 | }
|
| 4061 | ##
|
| 4062 |
|
| 4063 | #SeeAlso SkCanvas::drawRect Direction
|
| 4064 |
|
| 4065 | ##
|
| 4066 |
|
| 4067 | # ------------------------------------------------------------------------------
|
| 4068 |
|
| 4069 | #Method void addOval(const SkRect& oval, Direction dir = kCW_Direction)
|
| 4070 |
|
| 4071 | Add Oval to path, appending kMove_Verb, four kConic_Verb, and kClose_Verb.
|
| 4072 | Oval is upright ellipse bounded by Rect oval with radii equal to half oval width
|
| 4073 | and half oval height. Oval begins at (oval.fRight, oval.centerY()) and continues
|
| 4074 | clockwise if dir is kCW_Direction, counterclockwise if dir is kCCW_Direction.
|
| 4075 |
|
| 4076 | This form is identical to addOval(oval, dir, 1).
|
| 4077 |
|
| 4078 | #Param oval bounds of ellipse added. ##
|
| 4079 | #Param dir Direction to wind ellipse. ##
|
| 4080 |
|
| 4081 | #Example
|
| 4082 | #Height 120
|
| 4083 | SkPaint paint;
|
| 4084 | SkPath oval;
|
| 4085 | oval.addOval({20, 20, 160, 80});
|
| 4086 | canvas->drawPath(oval, paint);
|
| 4087 | ##
|
| 4088 |
|
| 4089 | #SeeAlso SkCanvas::drawOval Direction Oval
|
| 4090 |
|
| 4091 | ##
|
| 4092 |
|
| 4093 | # ------------------------------------------------------------------------------
|
| 4094 |
|
| 4095 | #Method void addOval(const SkRect& oval, Direction dir, unsigned start)
|
| 4096 |
|
| 4097 | Add Oval to Path, appending kMove_Verb, four kConic_Verb, and kClose_Verb.
|
| 4098 | Oval is upright ellipse bounded by Rect oval with radii equal to half oval width
|
| 4099 | and half oval height. Oval begins at start and continues
|
| 4100 | clockwise if dir is kCW_Direction, counterclockwise if dir is kCCW_Direction.
|
| 4101 |
|
| 4102 | #Table
|
| 4103 | #Legend
|
| 4104 | # start # Point ##
|
| 4105 | #Legend ##
|
| 4106 | # 0 # oval.centerX(), oval.fTop ##
|
| 4107 | # 1 # oval.fRight, oval.centerY() ##
|
| 4108 | # 2 # oval.centerX(), oval.fBottom ##
|
| 4109 | # 3 # oval.fLeft, oval.centerY() ##
|
| 4110 | #Table ##
|
| 4111 |
|
| 4112 | #Param oval bounds of ellipse added. ##
|
| 4113 | #Param dir Direction to wind ellipse. ##
|
| 4114 | #Param start index of initial point of ellipse. ##
|
| 4115 |
|
| 4116 | #Example
|
| 4117 | #Height 160
|
| 4118 | void draw(SkCanvas* canvas) {
|
| 4119 | const SkPoint arrow[] = { {0, -5}, {10, 0}, {0, 5} };
|
| 4120 | const SkRect rect = {10, 10, 54, 54};
|
| 4121 | SkPaint ovalPaint;
|
| 4122 | ovalPaint.setAntiAlias(true);
|
| 4123 | SkPaint textPaint(ovalPaint);
|
| 4124 | textPaint.setTextAlign(SkPaint::kCenter_Align);
|
| 4125 | ovalPaint.setStyle(SkPaint::kStroke_Style);
|
| 4126 | SkPaint arrowPaint(ovalPaint);
|
| 4127 | SkPath arrowPath;
|
| 4128 | arrowPath.addPoly(arrow, SK_ARRAY_COUNT(arrow), true);
|
| 4129 | arrowPaint.setPathEffect(SkPath1DPathEffect::Make(arrowPath, 176, 0,
|
| 4130 | SkPath1DPathEffect::kRotate_Style));
|
| 4131 | for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
|
| 4132 | for (unsigned start : { 0, 1, 2, 3 } ) {
|
| 4133 | SkPath path;
|
| 4134 | path.addOval(rect, direction, start);
|
| 4135 | canvas->drawPath(path, ovalPaint);
|
| 4136 | canvas->drawPath(path, arrowPaint);
|
| 4137 | canvas->drawText(&"0123"[start], 1, rect.centerX(), rect.centerY() + 5, textPaint);
|
| 4138 | canvas->translate(64, 0);
|
| 4139 | }
|
| 4140 | canvas->translate(-256, 72);
|
| 4141 | canvas->drawString(SkPath::kCW_Direction == direction ? "clockwise" : "counterclockwise",
|
| 4142 | 128, 0, textPaint);
|
| 4143 | }
|
| 4144 | }
|
| 4145 | ##
|
| 4146 |
|
| 4147 | #SeeAlso SkCanvas::drawOval Direction Oval
|
| 4148 |
|
| 4149 | ##
|
| 4150 |
|
| 4151 | # ------------------------------------------------------------------------------
|
| 4152 |
|
| 4153 | #Method void addCircle(SkScalar x, SkScalar y, SkScalar radius,
|
| 4154 | Direction dir = kCW_Direction)
|
| 4155 |
|
| 4156 | Add Circle centered at (x, y) of size radius to Path, appending kMove_Verb,
|
| 4157 | four kConic_Verb, and kClose_Verb. Circle begins at (x + radius, y) and
|
| 4158 | continues clockwise if dir is kCW_Direction, counterclockwise if dir is
|
| 4159 | kCCW_Direction.
|
| 4160 |
|
| 4161 | addCircle has no effect if radius is zero or negative.
|
| 4162 |
|
| 4163 | #Param x center of Circle. ##
|
| 4164 | #Param y center of Circle. ##
|
| 4165 | #Param radius distance from center to edge. ##
|
| 4166 | #Param dir Direction to wind Circle. ##
|
| 4167 |
|
| 4168 | #Example
|
| 4169 | void draw(SkCanvas* canvas) {
|
| 4170 | SkPaint paint;
|
| 4171 | paint.setAntiAlias(true);
|
| 4172 | paint.setStyle(SkPaint::kStroke_Style);
|
| 4173 | paint.setStrokeWidth(10);
|
| 4174 | for (int size = 10; size < 300; size += 20) {
|
| 4175 | SkPath path;
|
| 4176 | path.addCircle(128, 128, size, SkPath::kCW_Direction);
|
| 4177 | canvas->drawPath(path, paint);
|
| 4178 | }
|
| 4179 | }
|
| 4180 | ##
|
| 4181 |
|
| 4182 | #SeeAlso SkCanvas::drawCircle Direction Circle
|
| 4183 |
|
| 4184 | ##
|
| 4185 |
|
| 4186 | # ------------------------------------------------------------------------------
|
| 4187 |
|
| 4188 | #Method void addArc(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle)
|
| 4189 |
|
| 4190 | Append Arc to Path, as the start of new Contour. Arc added is part of ellipse
|
| 4191 | bounded by oval, from startAngle through sweepAngle. Both startAngle and
|
| 4192 | sweepAngle are measured in degrees, where zero degrees is aligned with the
|
| 4193 | positive x-axis, and positive sweeps extends Arc clockwise.
|
| 4194 |
|
| 4195 | If sweepAngle <= -360, or sweepAngle >= 360; and startAngle modulo 90 is nearly
|
| 4196 | zero, append Oval instead of Arc. Otherwise, sweepAngle values are treated
|
| 4197 | modulo 360, and Arc may or may not draw depending on numeric rounding.
|
| 4198 |
|
| 4199 | #Param oval bounds of ellipse containing Arc. ##
|
| 4200 | #Param startAngle starting angle of Arc in degrees. ##
|
| 4201 | #Param sweepAngle sweep, in degrees. Positive is clockwise; treated modulo 360. ##
|
| 4202 |
|
| 4203 | #Example
|
| 4204 | #Description
|
| 4205 | The middle row of the left and right columns draw differently from the entries
|
| 4206 | above and below because sweepAngle is outside of the range of +/-360,
|
| 4207 | and startAngle modulo 90 is not zero.
|
| 4208 | ##
|
| 4209 | void draw(SkCanvas* canvas) {
|
| 4210 | SkPaint paint;
|
| 4211 | for (auto start : { 0, 90, 135, 180, 270 } ) {
|
| 4212 | for (auto sweep : { -450.f, -180.f, -90.f, 90.f, 180.f, 360.1f } ) {
|
| 4213 | SkPath path;
|
| 4214 | path.addArc({10, 10, 35, 45}, start, sweep);
|
| 4215 | canvas->drawPath(path, paint);
|
| 4216 | canvas->translate(252 / 6, 0);
|
| 4217 | }
|
| 4218 | canvas->translate(-252, 255 / 5);
|
| 4219 | }
|
| 4220 | }
|
| 4221 | ##
|
| 4222 |
|
| 4223 | #SeeAlso Arc arcTo SkCanvas::drawArc
|
| 4224 |
|
| 4225 | ##
|
| 4226 |
|
| 4227 | # ------------------------------------------------------------------------------
|
| 4228 |
|
| 4229 | #Method void addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry,
|
| 4230 | Direction dir = kCW_Direction)
|
| 4231 |
|
| 4232 | Append Round_Rect to Path, creating a new closed Contour. Round_Rect has bounds
|
| 4233 | equal to rect; each corner is 90 degrees of an ellipse with radii (rx, ry). If
|
| 4234 | dir is kCW_Direction, Round_Rect starts at top-left of the lower-left corner and
|
| 4235 | winds clockwise. If dir is kCCW_Direction, Round_Rect starts at the bottom-left
|
| 4236 | of the upper-left corner and winds counterclockwise.
|
| 4237 |
|
| 4238 | If either rx or ry is too large, rx and ry are scaled uniformly until the
|
| 4239 | corners fit. If rx or ry is less than or equal to zero, addRoundRect appends
|
| 4240 | Rect rect to Path.
|
| 4241 |
|
| 4242 | After appending, Path may be empty, or may contain: Rect, Oval, or RoundRect.
|
| 4243 |
|
| 4244 | #Param rect bounds of Round_Rect. ##
|
| 4245 | #Param rx x-radius of rounded corners on the Round_Rect ##
|
| 4246 | #Param ry y-radius of rounded corners on the Round_Rect ##
|
| 4247 | #Param dir Direction to wind Round_Rect. ##
|
| 4248 |
|
| 4249 | #Example
|
| 4250 | #Description
|
| 4251 | If either radius is zero, path contains Rect and is drawn red.
|
| 4252 | If sides are only radii, path contains Oval and is drawn blue.
|
| 4253 | All remaining path draws are convex, and are drawn in gray; no
|
| 4254 | paths constructed from addRoundRect are concave, so none are
|
| 4255 | drawn in green.
|
| 4256 | ##
|
| 4257 | void draw(SkCanvas* canvas) {
|
| 4258 | SkPaint paint;
|
| 4259 | paint.setAntiAlias(true);
|
| 4260 | for (auto xradius : { 0, 7, 13, 20 } ) {
|
| 4261 | for (auto yradius : { 0, 9, 18, 40 } ) {
|
| 4262 | SkPath path;
|
| 4263 | path.addRoundRect({10, 10, 36, 46}, xradius, yradius);
|
| 4264 | paint.setColor(path.isRect(nullptr) ? SK_ColorRED : path.isOval(nullptr) ?
|
| 4265 | SK_ColorBLUE : path.isConvex() ? SK_ColorGRAY : SK_ColorGREEN);
|
| 4266 | canvas->drawPath(path, paint);
|
| 4267 | canvas->translate(64, 0);
|
| 4268 | }
|
| 4269 | canvas->translate(-256, 64);
|
| 4270 | }
|
| 4271 | }
|
| 4272 | ##
|
| 4273 |
|
| 4274 | #SeeAlso addRRect SkCanvas::drawRoundRect
|
| 4275 |
|
| 4276 | ##
|
| 4277 |
|
| 4278 | # ------------------------------------------------------------------------------
|
| 4279 |
|
| 4280 | #Method void addRoundRect(const SkRect& rect, const SkScalar radii[],
|
| 4281 | Direction dir = kCW_Direction)
|
| 4282 |
|
| 4283 | Append Round_Rect to Path, creating a new closed Contour. Round_Rect has bounds
|
| 4284 | equal to rect; each corner is 90 degrees of an ellipse with radii from the
|
| 4285 | array.
|
| 4286 |
|
| 4287 | #Table
|
| 4288 | #Legend
|
| 4289 | # radii index # location ##
|
| 4290 | #Legend ##
|
| 4291 | # 0 # x-radius of top-left corner ##
|
| 4292 | # 1 # y-radius of top-left corner ##
|
| 4293 | # 2 # x-radius of top-right corner ##
|
| 4294 | # 3 # y-radius of top-right corner ##
|
| 4295 | # 4 # x-radius of bottom-right corner ##
|
| 4296 | # 5 # y-radius of bottom-right corner ##
|
| 4297 | # 6 # x-radius of bottom-left corner ##
|
| 4298 | # 7 # y-radius of bottom-left corner ##
|
| 4299 | #Table ##
|
| 4300 |
|
| 4301 | If dir is kCW_Direction, Round_Rect starts at top-left of the lower-left corner
|
| 4302 | and winds clockwise. If dir is kCCW_Direction, Round_Rect starts at the
|
| 4303 | bottom-left of the upper-left corner and winds counterclockwise.
|
| 4304 |
|
| 4305 | If both radii on any side of rect exceed its length, all radii are scaled
|
| 4306 | uniformly until the corners fit. If either radius of a corner is less than or
|
| 4307 | equal to zero, both are treated as zero.
|
| 4308 |
|
| 4309 | After appending, Path may be empty, or may contain: Rect, Oval, or RoundRect.
|
| 4310 |
|
| 4311 | #Param rect bounds of Round_Rect. ##
|
| 4312 | #Param radii array of 8 SkScalar values, a radius pair for each corner. ##
|
| 4313 | #Param dir Direction to wind Round_Rect. ##
|
| 4314 |
|
| 4315 | #Example
|
| 4316 | void draw(SkCanvas* canvas) {
|
| 4317 | SkPaint paint;
|
| 4318 | paint.setAntiAlias(true);
|
| 4319 | SkScalar radii[] = { 80, 100, 0, 0, 40, 60, 0, 0 };
|
| 4320 | SkPath path;
|
| 4321 | SkMatrix rotate90;
|
| 4322 | rotate90.setRotate(90, 128, 128);
|
| 4323 | for (int i = 0; i < 4; ++i) {
|
| 4324 | path.addRoundRect({10, 10, 110, 110}, radii);
|
| 4325 | path.transform(rotate90);
|
| 4326 | }
|
| 4327 | canvas->drawPath(path, paint);
|
| 4328 | }
|
| 4329 | ##
|
| 4330 |
|
| 4331 | #SeeAlso addRRect SkCanvas::drawRoundRect
|
| 4332 |
|
| 4333 | ##
|
| 4334 |
|
| 4335 | # ------------------------------------------------------------------------------
|
| 4336 |
|
| 4337 | #Method void addRRect(const SkRRect& rrect, Direction dir = kCW_Direction)
|
| 4338 |
|
| 4339 | Add rrect to Path, creating a new closed Contour. If
|
| 4340 | dir is kCW_Direction, rrect starts at top-left of the lower-left corner and
|
| 4341 | winds clockwise. If dir is kCCW_Direction, rrect starts at the bottom-left
|
| 4342 | of the upper-left corner and winds counterclockwise.
|
| 4343 |
|
| 4344 | After appending, Path may be empty, or may contain: Rect, Oval, or RRect.
|
| 4345 |
|
| 4346 | #Param rrect bounds and radii of rounded rectangle. ##
|
| 4347 | #Param dir Direction to wind Round_Rect. ##
|
| 4348 |
|
| 4349 | #Example
|
| 4350 | void draw(SkCanvas* canvas) {
|
| 4351 | SkPaint paint;
|
| 4352 | paint.setAntiAlias(true);
|
| 4353 | SkRRect rrect;
|
| 4354 | SkVector radii[] = {{50, 50}, {0, 0}, {0, 0}, {50, 50}};
|
| 4355 | rrect.setRectRadii({10, 10, 110, 110}, radii);
|
| 4356 | SkPath path;
|
| 4357 | SkMatrix rotate90;
|
| 4358 | rotate90.setRotate(90, 128, 128);
|
| 4359 | for (int i = 0; i < 4; ++i) {
|
| 4360 | path.addRRect(rrect);
|
| 4361 | path.transform(rotate90);
|
| 4362 | }
|
| 4363 | canvas->drawPath(path, paint);
|
| 4364 | }
|
| 4365 | ##
|
| 4366 |
|
| 4367 | #SeeAlso addRoundRect SkCanvas::drawRRect
|
| 4368 |
|
| 4369 | ##
|
| 4370 |
|
| 4371 | # ------------------------------------------------------------------------------
|
| 4372 |
|
| 4373 | #Method void addRRect(const SkRRect& rrect, Direction dir, unsigned start)
|
| 4374 |
|
| 4375 | Add rrect to Path, creating a new closed Contour. If dir is kCW_Direction, rrect
|
| 4376 | winds clockwise; if dir is kCCW_Direction, rrect winds counterclockwise.
|
| 4377 | start determines the first point of rrect to add.
|
| 4378 |
|
| 4379 | #Table
|
| 4380 | #Legend
|
| 4381 | # start # location ##
|
| 4382 | #Legend ##
|
| 4383 | # 0 # right of top-left corner ##
|
| 4384 | # 1 # left of top-right corner ##
|
| 4385 | # 2 # bottom of top-right corner ##
|
| 4386 | # 3 # top of bottom-right corner ##
|
| 4387 | # 4 # left of bottom-right corner ##
|
| 4388 | # 5 # right of bottom-left corner ##
|
| 4389 | # 6 # top of bottom-left corner ##
|
| 4390 | # 7 # bottom of top-left corner ##
|
| 4391 | #Table ##
|
| 4392 |
|
| 4393 | After appending, Path may be empty, or may contain: Rect, Oval, or RRect.
|
| 4394 |
|
| 4395 | #Param rrect bounds and radii of rounded rectangle. ##
|
| 4396 | #Param dir Direction to wind RRect. ##
|
| 4397 | #Param start Index of initial point of RRect. ##
|
| 4398 |
|
| 4399 | #Example
|
| 4400 | void draw(SkCanvas* canvas) {
|
| 4401 | SkPaint paint;
|
| 4402 | paint.setAntiAlias(true);
|
| 4403 | SkRRect rrect;
|
| 4404 | rrect.setRectXY({40, 40, 215, 215}, 50, 50);
|
| 4405 | SkPath path;
|
| 4406 | path.addRRect(rrect);
|
| 4407 | canvas->drawPath(path, paint);
|
| 4408 | for (int start = 0; start < 8; ++start) {
|
| 4409 | SkPath textPath;
|
| 4410 | textPath.addRRect(rrect, SkPath::kCW_Direction, start);
|
| 4411 | canvas->drawTextOnPathHV(&"01234567"[start], 1, textPath, 0, -5, paint);
|
| 4412 | }
|
| 4413 | }
|
| 4414 | ##
|
| 4415 |
|
| 4416 | #SeeAlso addRoundRect SkCanvas::drawRRect
|
| 4417 |
|
| 4418 | ##
|
| 4419 |
|
| 4420 | # ------------------------------------------------------------------------------
|
| 4421 |
|
| 4422 | #Method void addPoly(const SkPoint pts[], int count, bool close)
|
| 4423 |
|
| 4424 | Add Contour created from Line Array. Given count pts, addPoly adds
|
| 4425 | count - 1 Line segments. Contour added starts at pt[0], then adds a line
|
| 4426 | for every additional Point in pts array. If close is true, addPoly
|
| 4427 | appends kClose_Verb to Path, connecting pts[count - 1] and pts[0].
|
| 4428 |
|
| 4429 | If count is zero, append kMove_Verb to path.
|
| 4430 | addPoly has no effect if count is less than one.
|
| 4431 |
|
| 4432 | #Param pts Array of Line sharing end and start Point. ##
|
| 4433 | #Param count Length of Point array. ##
|
| 4434 | #Param close true to add Line connecting Contour end and start. ##
|
| 4435 |
|
| 4436 | #Example
|
| 4437 | void draw(SkCanvas* canvas) {
|
| 4438 | SkPaint paint;
|
| 4439 | paint.setStrokeWidth(15);
|
| 4440 | paint.setStrokeCap(SkPaint::kRound_Cap);
|
| 4441 | const SkPoint points[] = {{20, 20}, {70, 20}, {40, 90}};
|
| 4442 | for (bool close : { false, true } ) {
|
| 4443 | SkPath path;
|
| 4444 | path.addPoly(points, SK_ARRAY_COUNT(points), close);
|
| 4445 | for (auto style : {SkPaint::kStroke_Style, SkPaint::kFill_Style,
|
| 4446 | SkPaint::kStrokeAndFill_Style} ) {
|
| 4447 | paint.setStyle(style);
|
| 4448 | canvas->drawPath(path, paint);
|
| 4449 | canvas->translate(85, 0);
|
| 4450 | }
|
| 4451 | canvas->translate(-255, 128);
|
| 4452 | }
|
| 4453 | }
|
| 4454 | ##
|
| 4455 |
|
| 4456 | #SeeAlso SkCanvas::drawPoints
|
| 4457 |
|
| 4458 | ##
|
| 4459 |
|
| 4460 | # ------------------------------------------------------------------------------
|
| 4461 |
|
| 4462 | #Enum AddPathMode
|
| 4463 |
|
| 4464 | #Code
|
| 4465 | enum AddPathMode {
|
| 4466 | kAppend_AddPathMode
|
| 4467 | kExtend_AddPathMode
|
| 4468 | };
|
| 4469 | ##
|
| 4470 |
|
| 4471 | AddPathMode chooses how addPath appends. Adding one Path to another can extend
|
| 4472 | the last Contour or start a new Contour.
|
| 4473 |
|
| 4474 | #Const kAppend_AddPathMode
|
| 4475 | Path Verbs, Points, and Weights are appended to destination unaltered.
|
| 4476 | Since Path Verb_Array begins with kMove_Verb if src is not empty, this
|
| 4477 | starts a new Contour.
|
| 4478 | ##
|
| 4479 | #Const kExtend_AddPathMode
|
| 4480 | If destination is closed or empty, start a new Contour. If destination
|
| 4481 | is not empty, add Line from Last_Point to added Path first Point. Skip added
|
| 4482 | Path initial kMove_Verb, then append remining Verbs, Points, and Weights.
|
| 4483 | ##
|
| 4484 |
|
| 4485 | #Example
|
| 4486 | #Description
|
| 4487 | test is built from path, open on the top row, and closed on the bottom row.
|
| 4488 | The left column uses kAppend_AddPathMode; the right uses kExtend_AddPathMode.
|
| 4489 | The top right composition is made up of one contour; the other three have two.
|
| 4490 | ##
|
| 4491 | #Height 180
|
| 4492 | SkPath path, path2; |
| 4493 | path.moveTo(20, 20); |
| 4494 | path.lineTo(20, 40); |
| 4495 | path.lineTo(40, 20); |
| 4496 | path2.moveTo(60, 60); |
| 4497 | path2.lineTo(80, 60); |
| 4498 | path2.lineTo(80, 40); |
| 4499 | SkPaint paint; |
| 4500 | paint.setStyle(SkPaint::kStroke_Style); |
| 4501 | for (int i = 0; i < 2; i++) { |
| 4502 | for (auto addPathMode : { SkPath::kAppend_AddPathMode, SkPath::kExtend_AddPathMode } ) { |
| 4503 | SkPath test(path); |
| 4504 | test.addPath(path2, addPathMode); |
| 4505 | canvas->drawPath(test, paint); |
| 4506 | canvas->translate(100, 0); |
| 4507 | } |
| 4508 | canvas->translate(-200, 100); |
| 4509 | path.close(); |
| 4510 | } |
| 4511 | ##
|
| 4512 |
|
| 4513 | #SeeAlso addPath reverseAddPath
|
| 4514 |
|
| 4515 | ##
|
| 4516 |
|
| 4517 | # ------------------------------------------------------------------------------
|
| 4518 |
|
| 4519 | #Method void addPath(const SkPath& src, SkScalar dx, SkScalar dy,
|
| 4520 | AddPathMode mode = kAppend_AddPathMode)
|
| 4521 |
|
| 4522 | Append src to Path, offset by (dx, dy).
|
| 4523 |
|
| 4524 | If mode is kAppend_AddPathMode, src Verb_Array, Point_Array, and Weights are
|
| 4525 | added unaltered. If mode is kExtend_AddPathMode, add Line before appending
|
| 4526 | Verbs, Points, and Weights.
|
| 4527 |
|
| 4528 | #Param src Path Verbs, Points, and Weights to add. ##
|
| 4529 | #Param dx offset added to src Point_Array x coordinates. ##
|
| 4530 | #Param dy offset added to src Point_Array y coordinates. ##
|
| 4531 | #Param mode kAppend_AddPathMode or kExtend_AddPathMode. ##
|
| 4532 |
|
| 4533 | #Example
|
| 4534 | #Height 180
|
| 4535 | SkPaint paint; |
| 4536 | paint.setTextSize(128); |
| 4537 | paint.setFakeBoldText(true); |
| 4538 | SkPath dest, text; |
| 4539 | paint.getTextPath("O", 1, 50, 120, &text); |
| 4540 | for (int i = 0; i < 3; i++) { |
| 4541 | dest.addPath(text, i * 20, i * 20); |
| 4542 | } |
| 4543 | Simplify(dest, &dest); |
| 4544 | paint.setStyle(SkPaint::kStroke_Style); |
| 4545 | paint.setStrokeWidth(3); |
| 4546 | canvas->drawPath(dest, paint); |
| 4547 | ##
|
| 4548 |
|
| 4549 | #SeeAlso AddPathMode offset() reverseAddPath
|
| 4550 |
|
| 4551 | ##
|
| 4552 |
|
| 4553 | # ------------------------------------------------------------------------------
|
| 4554 |
|
| 4555 | #Method void addPath(const SkPath& src, AddPathMode mode = kAppend_AddPathMode)
|
| 4556 |
|
| 4557 | Append src to Path.
|
| 4558 |
|
| 4559 | If mode is kAppend_AddPathMode, src Verb_Array, Point_Array, and Weights are
|
| 4560 | added unaltered. If mode is kExtend_AddPathMode, add Line before appending
|
| 4561 | Verbs, Points, and Weights.
|
| 4562 |
|
| 4563 | #Param src Path Verbs, Points, and Weights to add. ##
|
| 4564 | #Param mode kAppend_AddPathMode or kExtend_AddPathMode. ##
|
| 4565 |
|
| 4566 | #Example
|
| 4567 | #Height 80
|
| 4568 | SkPaint paint; |
| 4569 | paint.setStyle(SkPaint::kStroke_Style); |
| 4570 | SkPath dest, path; |
| 4571 | path.addOval({-80, 20, 0, 60}, SkPath::kCW_Direction, 1); |
| 4572 | for (int i = 0; i < 2; i++) { |
| 4573 | dest.addPath(path, SkPath::kExtend_AddPathMode); |
| 4574 | dest.offset(100, 0); |
| 4575 | } |
| 4576 | canvas->drawPath(dest, paint);
|
| 4577 | ##
|
| 4578 |
|
| 4579 | #SeeAlso AddPathMode reverseAddPath
|
| 4580 |
|
| 4581 | ##
|
| 4582 |
|
| 4583 | # ------------------------------------------------------------------------------
|
| 4584 |
|
| 4585 | #Method void addPath(const SkPath& src, const SkMatrix& matrix, AddPathMode mode = kAppend_AddPathMode)
|
| 4586 |
|
| 4587 | Append src to Path, transformed by matrix. Transformed curves may have different
|
| 4588 | Verbs, Points, and Weights.
|
| 4589 |
|
| 4590 | If mode is kAppend_AddPathMode, src Verb_Array, Point_Array, and Weights are
|
| 4591 | added unaltered. If mode is kExtend_AddPathMode, add Line before appending
|
| 4592 | Verbs, Points, and Weights.
|
| 4593 |
|
| 4594 | #Param src Path Verbs, Points, and Weights to add. ##
|
| 4595 | #Param matrix Transform applied to src. ##
|
| 4596 | #Param mode kAppend_AddPathMode or kExtend_AddPathMode. ##
|
| 4597 |
|
| 4598 | #Example
|
| 4599 | #Height 160
|
| 4600 | SkPaint paint; |
| 4601 | paint.setStyle(SkPaint::kStroke_Style); |
| 4602 | SkPath dest, path; |
| 4603 | path.addOval({20, 20, 200, 120}, SkPath::kCW_Direction, 1); |
| 4604 | for (int i = 0; i < 6; i++) { |
| 4605 | SkMatrix matrix; |
| 4606 | matrix.reset(); |
| 4607 | matrix.setPerspX(i / 400.f); |
| 4608 | dest.addPath(path, matrix); |
| 4609 | } |
| 4610 | canvas->drawPath(dest, paint); |
| 4611 | ##
|
| 4612 |
|
| 4613 | #SeeAlso AddPathMode transform() offset() reverseAddPath
|
| 4614 |
|
| 4615 | ##
|
| 4616 |
|
| 4617 | # ------------------------------------------------------------------------------
|
| 4618 |
|
| 4619 | #Method void reverseAddPath(const SkPath& src)
|
| 4620 |
|
| 4621 | Append src to Path, from back to front.
|
| 4622 | Reversed src always appends a new Contour to Path.
|
| 4623 |
|
| 4624 | #Param src Path Verbs, Points, and Weights to add. ##
|
| 4625 |
|
| 4626 | #Example
|
| 4627 | #Height 200
|
| 4628 | SkPath path; |
| 4629 | path.moveTo(20, 20); |
| 4630 | path.lineTo(20, 40); |
| 4631 | path.lineTo(40, 20); |
| 4632 | SkPaint paint; |
| 4633 | paint.setStyle(SkPaint::kStroke_Style); |
| 4634 | for (int i = 0; i < 2; i++) { |
| 4635 | SkPath path2; |
| 4636 | path2.moveTo(60, 60); |
| 4637 | path2.lineTo(80, 60); |
| 4638 | path2.lineTo(80, 40); |
| 4639 | for (int j = 0; j < 2; j++) { |
| 4640 | SkPath test(path); |
| 4641 | test.reverseAddPath(path2); |
| 4642 | canvas->drawPath(test, paint); |
| 4643 | canvas->translate(100, 0); |
| 4644 | path2.close(); |
| 4645 | } |
| 4646 | canvas->translate(-200, 100); |
| 4647 | path.close(); |
| 4648 | } |
| 4649 | ##
|
| 4650 |
|
| 4651 | #SeeAlso AddPathMode transform() offset() addPath
|
| 4652 |
|
| 4653 | ##
|
| 4654 |
|
| 4655 | # ------------------------------------------------------------------------------
|
| 4656 |
|
| 4657 | #Method void offset(SkScalar dx, SkScalar dy, SkPath* dst) const
|
| 4658 |
|
| 4659 | Offset Point_Array by (dx, dy). Offset Path replaces dst.
|
| 4660 | If dst is nullptr, Path is replaced by offset data.
|
| 4661 |
|
| 4662 | #Param dx offset added to Point_Array x coordinates. ##
|
| 4663 | #Param dy offset added to Point_Array y coordinates. ##
|
| 4664 | #Param dst overwritten, translated copy of Path; may be nullptr. ##
|
| 4665 |
|
| 4666 | #Example
|
| 4667 | #Height 60
|
| 4668 | SkPath pattern; |
| 4669 | pattern.moveTo(20, 20); |
| 4670 | pattern.lineTo(20, 40); |
| 4671 | pattern.lineTo(40, 20); |
| 4672 | SkPaint paint; |
| 4673 | paint.setStyle(SkPaint::kStroke_Style); |
| 4674 | for (int i = 0; i < 10; i++) { |
| 4675 | SkPath path; |
| 4676 | pattern.offset(20 * i, 0, &path); |
| 4677 | canvas->drawPath(path, paint); |
| 4678 | } |
| 4679 | ##
|
| 4680 |
|
| 4681 | #SeeAlso addPath transform
|
| 4682 |
|
| 4683 | ##
|
| 4684 |
|
| 4685 | # ------------------------------------------------------------------------------
|
| 4686 |
|
| 4687 | #Method void offset(SkScalar dx, SkScalar dy)
|
| 4688 |
|
| 4689 | Offset Point_Array by (dx, dy). Path is replaced by offset data.
|
| 4690 |
|
| 4691 | #Param dx offset added to Point_Array x coordinates. ##
|
| 4692 | #Param dy offset added to Point_Array y coordinates. ##
|
| 4693 |
|
| 4694 | #Example
|
| 4695 | #Height 60
|
| 4696 | SkPath path; |
| 4697 | path.moveTo(20, 20); |
| 4698 | path.lineTo(20, 40); |
| 4699 | path.lineTo(40, 20); |
| 4700 | SkPaint paint; |
| 4701 | paint.setStyle(SkPaint::kStroke_Style); |
| 4702 | for (int i = 0; i < 10; i++) { |
| 4703 | canvas->drawPath(path, paint); |
| 4704 | path.offset(20, 0); |
| 4705 | } |
| 4706 | ##
|
| 4707 |
|
| 4708 | #SeeAlso addPath transform SkCanvas::translate()
|
| 4709 |
|
| 4710 | ##
|
| 4711 |
|
| 4712 | # ------------------------------------------------------------------------------
|
| 4713 |
|
| 4714 | #Method void transform(const SkMatrix& matrix, SkPath* dst) const
|
| 4715 |
|
| 4716 | Transform Verb_Array, Point_Array, and weight by matrix.
|
| 4717 | transform may change Verbs and increase their number.
|
| 4718 | Transformed Path replaces dst; if dst is nullptr, original data
|
| 4719 | is replaced.
|
| 4720 |
|
| 4721 | #Param matrix Matrix to apply to Path. ##
|
| 4722 | #Param dst overwritten, transformed copy of Path; may be nullptr. ##
|
| 4723 |
|
| 4724 | #Example
|
| 4725 | #Height 200 |
| 4726 | SkPath pattern; |
| 4727 | pattern.moveTo(100, 100); |
| 4728 | pattern.lineTo(100, 20); |
| 4729 | pattern.lineTo(20, 100); |
| 4730 | SkPaint paint; |
| 4731 | paint.setStyle(SkPaint::kStroke_Style); |
| 4732 | for (int i = 0; i < 10; i++) { |
| 4733 | SkPath path; |
| 4734 | SkMatrix matrix; |
| 4735 | matrix.setRotate(36 * i, 100, 100); |
| 4736 | pattern.transform(matrix, &path); |
| 4737 | canvas->drawPath(path, paint); |
| 4738 | }
|
| 4739 | ##
|
| 4740 |
|
| 4741 | #SeeAlso addPath offset SkCanvas::concat() SkMatrix
|
| 4742 |
|
| 4743 | ##
|
| 4744 |
|
| 4745 | # ------------------------------------------------------------------------------
|
| 4746 |
|
| 4747 | #Method void transform(const SkMatrix& matrix)
|
| 4748 |
|
| 4749 | Transform Verb_Array, Point_Array, and weight by matrix.
|
| 4750 | transform may change Verbs and increase their number.
|
| 4751 | Path is replaced by transformed data.
|
| 4752 |
|
| 4753 | #Param matrix Matrix to apply to Path. ##
|
| 4754 |
|
| 4755 | #Example
|
| 4756 | #Height 200 |
| 4757 | SkPath path; |
| 4758 | path.moveTo(100, 100); |
| 4759 | path.quadTo(100, 20, 20, 100); |
| 4760 | SkPaint paint; |
| 4761 | paint.setStyle(SkPaint::kStroke_Style); |
| 4762 | for (int i = 0; i < 10; i++) { |
| 4763 | SkMatrix matrix; |
| 4764 | matrix.setRotate(36, 100, 100); |
| 4765 | path.transform(matrix); |
| 4766 | canvas->drawPath(path, paint); |
| 4767 | }
|
| 4768 | ##
|
| 4769 |
|
| 4770 | #SeeAlso addPath offset SkCanvas::concat() SkMatrix
|
| 4771 |
|
| 4772 | ##
|
| 4773 |
|
| 4774 | # ------------------------------------------------------------------------------
|
| 4775 |
|
| 4776 | #Subtopic Last_Point |
| 4777 | |
| 4778 | Path is defined cumulatively, often by adding a segment to the end of last |
| 4779 | Contour. Last_Point of Contour is shared as first Point of added Line or Curve. |
| 4780 | Last_Point can be read and written directly with getLastPt and setLastPt. |
| 4781 | |
| 4782 | #Method bool getLastPt(SkPoint* lastPt) const
|
| 4783 |
|
| 4784 | Returns Last_Point on Path in lastPt. Returns false if Point_Array is empty,
|
| 4785 | storing (0, 0) if lastPt is not nullptr.
|
| 4786 |
|
| 4787 | #Param lastPt storage for final Point in Point_Array; may be nullptr. ##
|
| 4788 |
|
| 4789 | #Return true if Point_Array contains one or more Points. ##
|
| 4790 |
|
| 4791 | #Example
|
| 4792 | SkPath path; |
| 4793 | path.moveTo(100, 100); |
| 4794 | path.quadTo(100, 20, 20, 100); |
| 4795 | SkMatrix matrix; |
| 4796 | matrix.setRotate(36, 100, 100); |
| 4797 | path.transform(matrix); |
| 4798 | SkPoint last; |
| 4799 | path.getLastPt(&last); |
| 4800 | SkDebugf("last point: %g, %g\n", last.fX, last.fY);
|
| 4801 | #StdOut
|
| 4802 | last point: 35.2786, 52.9772
|
| 4803 | ##
|
| 4804 | ##
|
| 4805 |
|
| 4806 | #SeeAlso setLastPt
|
| 4807 |
|
| 4808 | ##
|
| 4809 |
|
| 4810 | #Method void setLastPt(SkScalar x, SkScalar y)
|
| 4811 |
|
| 4812 | Set Last_Point to (x, y). If Point_Array is empty, append kMove_Verb to
|
| 4813 | Verb_Array and (x, y) to Point_Array.
|
| 4814 |
|
| 4815 | #Param x set x-coordinate of Last_Point. ##
|
| 4816 | #Param y set y-coordinate of Last_Point. ##
|
| 4817 |
|
| 4818 | #Example
|
| 4819 | #Height 128
|
| 4820 | SkPaint paint; |
| 4821 | paint.setTextSize(128); |
| 4822 | SkPath path; |
| 4823 | paint.getTextPath("@", 1, 60, 100, &path); |
| 4824 | path.setLastPt(20, 120); |
| 4825 | canvas->drawPath(path, paint);
|
| 4826 | ##
|
| 4827 |
|
| 4828 | #SeeAlso getLastPt
|
| 4829 |
|
| 4830 | ##
|
| 4831 |
|
| 4832 | #Method void setLastPt(const SkPoint& p)
|
| 4833 |
|
| 4834 | Set the last point on the path. If no points have been added, moveTo(p)
|
| 4835 | is automatically called.
|
| 4836 |
|
| 4837 | #Param p set value of Last_Point. ##
|
| 4838 |
|
| 4839 | #Example
|
| 4840 | #Height 128
|
| 4841 | SkPaint paint; |
| 4842 | paint.setTextSize(128); |
| 4843 | SkPath path, path2; |
| 4844 | paint.getTextPath("A", 1, 60, 100, &path); |
| 4845 | paint.getTextPath("Z", 1, 60, 100, &path2); |
| 4846 | SkPoint pt, pt2; |
| 4847 | path.getLastPt(&pt); |
| 4848 | path2.getLastPt(&pt2); |
| 4849 | path.setLastPt(pt2); |
| 4850 | path2.setLastPt(pt); |
| 4851 | canvas->drawPath(path, paint); |
| 4852 | canvas->drawPath(path2, paint); |
| 4853 | ##
|
| 4854 |
|
| 4855 | #SeeAlso getLastPt
|
| 4856 |
|
| 4857 | ##
|
| 4858 |
|
| 4859 | #Subtopic Last_Point ##
|
| 4860 |
|
| 4861 | # ------------------------------------------------------------------------------
|
| 4862 |
|
| 4863 | #Enum SegmentMask
|
| 4864 |
|
| 4865 | #Code
|
| 4866 | enum SegmentMask {
|
| 4867 | kLine_SegmentMask = 1 << 0
|
| 4868 | kQuad_SegmentMask = 1 << 1
|
| 4869 | kConic_SegmentMask = 1 << 2
|
| 4870 | kCubic_SegmentMask = 1 << 3
|
| 4871 | };
|
| 4872 | ##
|
| 4873 |
|
| 4874 | SegmentMask constants correspond to each drawing Verb type in Path; for
|
| 4875 | instance, if Path only contains Lines, only the kLine_SegmentMask bit is set.
|
| 4876 |
|
| 4877 | #Bug 6785 ##
|
| 4878 | #Const kLine_SegmentMask 1
|
| 4879 | Set if Verb_Array contains kLine_Verb.
|
| 4880 | ##
|
| 4881 | #Const kQuad_SegmentMask 2
|
| 4882 | Set if Verb_Array contains kQuad_Verb. Note that conicTo may add a Quad.
|
| 4883 | ##
|
| 4884 | #Const kConic_SegmentMask 4
|
| 4885 | Set if Verb_Array contains kConic_Verb.
|
| 4886 | ##
|
| 4887 | #Const kCubic_SegmentMask 8
|
| 4888 | Set if Verb_Array contains kCubic_Verb.
|
| 4889 | ##
|
| 4890 |
|
| 4891 | #Example
|
| 4892 | #Description
|
| 4893 | When conicTo has a weight of one, Quad is added to Path.
|
| 4894 | ##
|
| 4895 | SkPath path;
|
| 4896 | path.conicTo(10, 10, 20, 30, 1);
|
| 4897 | SkDebugf("Path kConic_SegmentMask is %s\n", path.getSegmentMasks() &
|
| 4898 | SkPath::kConic_SegmentMask ? "set" : "clear");
|
| 4899 | SkDebugf("Path kQuad_SegmentMask is %s\n", path.getSegmentMasks() &
|
| 4900 | SkPath::kQuad_SegmentMask ? "set" : "clear");
|
| 4901 | #StdOut
|
| 4902 | Path kConic_SegmentMask is clear
|
| 4903 | Path kQuad_SegmentMask is set
|
| 4904 | ##
|
| 4905 | ##
|
| 4906 |
|
| 4907 | #SeeAlso getSegmentMasks Verb
|
| 4908 |
|
| 4909 | ##
|
| 4910 |
|
| 4911 | # ------------------------------------------------------------------------------
|
| 4912 |
|
| 4913 | #Method uint32_t getSegmentMasks() const
|
| 4914 |
|
| 4915 | Returns a mask, where each set bit corresponds to a SegmentMask constant
|
| 4916 | if Path contains one or more Verbs of that type.
|
| 4917 | Returns zero if Path contains no Lines, Quads, Conics, or Cubics.
|
| 4918 |
|
| 4919 | getSegmentMasks() returns a cached result; it is very fast.
|
| 4920 |
|
| 4921 | #Return SegmentMask bits or zero. ##
|
| 4922 |
|
| 4923 | #Example
|
| 4924 | SkPath path;
|
| 4925 | path.quadTo(20, 30, 40, 50);
|
| 4926 | path.close();
|
| 4927 | const char* masks[] = { "line", "quad", "conic", "cubic" };
|
| 4928 | int index = 0;
|
| 4929 | for (auto mask : { SkPath::kLine_SegmentMask, SkPath::kQuad_SegmentMask,
|
| 4930 | SkPath::kConic_SegmentMask, SkPath::kCubic_SegmentMask } ) {
|
| 4931 | if (mask & path.getSegmentMasks()) {
|
| 4932 | SkDebugf("mask %s set\n", masks[index]);
|
| 4933 | }
|
| 4934 | ++index;
|
| 4935 | }
|
| 4936 | #StdOut
|
| 4937 | mask quad set
|
| 4938 | ##
|
| 4939 | ##
|
| 4940 |
|
| 4941 | #SeeAlso getSegmentMasks Verb
|
| 4942 |
|
| 4943 | ##
|
| 4944 |
|
| 4945 | # ------------------------------------------------------------------------------
|
| 4946 |
|
| 4947 | #Method bool contains(SkScalar x, SkScalar y) const
|
| 4948 |
|
| 4949 | Returns true if the point (x, y) is contained by Path, taking into
|
| 4950 | account FillType.
|
| 4951 |
|
| 4952 | #Table
|
| 4953 | #Legend
|
| 4954 | # FillType # contains() returns true if Point is enclosed by ##
|
| 4955 | ##
|
| 4956 | # kWinding_FillType # a non-zero sum of Contour Directions. ##
|
| 4957 | # kEvenOdd_FillType # an odd number of Contours. ##
|
| 4958 | # kInverseWinding_FillType # a zero sum of Contour Directions. ##
|
| 4959 | # kInverseEvenOdd_FillType # and even number of Contours. ##
|
| 4960 | ##
|
| 4961 |
|
| 4962 | #Param x x-coordinate of containment test. ##
|
| 4963 | #Param y y-coordinate of containment test. ##
|
| 4964 |
|
| 4965 | #Return true if Point is in Path. ##
|
| 4966 |
|
| 4967 | #Example
|
| 4968 | SkPath path;
|
| 4969 | SkPaint paint;
|
| 4970 | paint.setTextSize(256);
|
| 4971 | paint.getTextPath("&", 1, 30, 220, &path);
|
| 4972 | for (int y = 2; y < 256; y += 9) {
|
| 4973 | for (int x = 2; x < 256; x += 9) {
|
| 4974 | int coverage = 0;
|
| 4975 | for (int iy = -4; iy <= 4; iy += 2) {
|
| 4976 | for (int ix = -4; ix <= 4; ix += 2) {
|
| 4977 | coverage += path.contains(x + ix, y + iy);
|
| 4978 | }
|
| 4979 | }
|
| 4980 | paint.setColor(SkColorSetARGB(0x5f, 0xff * coverage / 25, 0, 0xff * (25 - coverage) / 25));
|
| 4981 | canvas->drawCircle(x, y, 8, paint);
|
| 4982 | }
|
| 4983 | }
|
| 4984 | ##
|
| 4985 |
|
| 4986 | #SeeAlso conservativelyContainsRect Fill_Type Op
|
| 4987 |
|
| 4988 | ##
|
| 4989 |
|
| 4990 | # ------------------------------------------------------------------------------
|
| 4991 |
|
| 4992 | #Method void dump(SkWStream* stream, bool forceClose, bool dumpAsHex) const
|
| 4993 |
|
| 4994 | Writes text representation of Path to stream. If stream is nullptr, dump() writes to
|
| 4995 | stdout. Set forceClose to true to get
|
| 4996 | edges used to fill Path. Set dumpAsHex true to get exact binary representations
|
| 4997 | of floating point numbers used in Point_Array and Weights.
|
| 4998 |
|
| 4999 | #Param stream writable Stream receiving Path text representation; may be nullptr. ##
|
| 5000 | #Param forceClose true if missing kClose_Verb is output. ##
|
| 5001 | #Param dumpAsHex true if SkScalar values are written as hexidecimal. ##
|
| 5002 |
|
| 5003 | #Example
|
| 5004 | SkPath path;
|
| 5005 | path.quadTo(20, 30, 40, 50);
|
| 5006 | for (bool forceClose : { false, true } ) {
|
| 5007 | for (bool dumpAsHex : { false, true } ) {
|
| 5008 | path.dump(nullptr, forceClose, dumpAsHex);
|
| 5009 | SkDebugf("\n");
|
| 5010 | }
|
| 5011 | }
|
| 5012 | #StdOut
|
| 5013 | path.setFillType(SkPath::kWinding_FillType);
|
| 5014 | path.moveTo(0, 0);
|
| 5015 | path.quadTo(20, 30, 40, 50);
|
| 5016 |
|
| 5017 | path.setFillType(SkPath::kWinding_FillType);
|
| 5018 | path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
|
| 5019 | path.quadTo(SkBits2Float(0x41a00000), SkBits2Float(0x41f00000), SkBits2Float(0x42200000), SkBits2Float(0x42480000)); // 20, 30, 40, 50
|
| 5020 |
|
| 5021 | path.setFillType(SkPath::kWinding_FillType);
|
| 5022 | path.moveTo(0, 0);
|
| 5023 | path.quadTo(20, 30, 40, 50);
|
| 5024 | path.lineTo(0, 0);
|
| 5025 | path.close();
|
| 5026 |
|
| 5027 | path.setFillType(SkPath::kWinding_FillType);
|
| 5028 | path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
|
| 5029 | path.quadTo(SkBits2Float(0x41a00000), SkBits2Float(0x41f00000), SkBits2Float(0x42200000), SkBits2Float(0x42480000)); // 20, 30, 40, 50
|
| 5030 | path.lineTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
|
| 5031 | path.close();
|
| 5032 | ##
|
| 5033 | ##
|
| 5034 |
|
| 5035 | #SeeAlso SkRect::dump() SkRRect::dump() SkPathMeasure::dump()
|
| 5036 |
|
| 5037 | ##
|
| 5038 |
|
| 5039 | # ------------------------------------------------------------------------------
|
| 5040 |
|
| 5041 | #Method void dump() const
|
| 5042 |
|
| 5043 | Writes text representation of Path to stdout. The representation may be
|
| 5044 | directly compiled as C++ code. Floating point values are written
|
| 5045 | with limited precision; it may not be possible to reconstruct original Path
|
| 5046 | from output.
|
| 5047 |
|
| 5048 | #Example
|
| 5049 | SkPath path, copy;
|
| 5050 | path.lineTo(6.f / 7, 2.f / 3);
|
| 5051 | path.dump();
|
| 5052 | copy.setFillType(SkPath::kWinding_FillType);
|
| 5053 | copy.moveTo(0, 0);
|
| 5054 | copy.lineTo(0.857143f, 0.666667f);
|
| 5055 | SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not ");
|
| 5056 | #StdOut
|
| 5057 | path.setFillType(SkPath::kWinding_FillType);
|
| 5058 | path.moveTo(0, 0);
|
| 5059 | path.lineTo(0.857143f, 0.666667f);
|
| 5060 | path is not equal to copy
|
| 5061 | ##
|
| 5062 | ##
|
| 5063 |
|
| 5064 | #SeeAlso dumpHex SkRect::dump() SkRRect::dump() SkPathMeasure::dump() writeToMemory
|
| 5065 |
|
| 5066 | ##
|
| 5067 |
|
| 5068 | # ------------------------------------------------------------------------------
|
| 5069 |
|
| 5070 | #Method void dumpHex() const
|
| 5071 |
|
| 5072 | Writes text representation of Path to stdout. The representation may be
|
| 5073 | directly compiled as C++ code. Floating point values are written
|
| 5074 | in hexadecimal to preserve their exact bit pattern. The output reconstructs the
|
| 5075 | original Path.
|
| 5076 |
|
| 5077 | Use dumpHex when submitting #A bug reports against Skia # http://bug.skia.org ##.
|
| 5078 | Slight value changes in Point_Array may cause the bug to disappear.
|
| 5079 |
|
| 5080 | #Example
|
| 5081 | SkPath path, copy;
|
| 5082 | path.lineTo(6.f / 7, 2.f / 3);
|
| 5083 | path.dumpHex();
|
| 5084 | copy.setFillType(SkPath::kWinding_FillType);
|
| 5085 | copy.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
|
| 5086 | copy.lineTo(SkBits2Float(0x3f5b6db7), SkBits2Float(0x3f2aaaab)); // 0.857143f, 0.666667f
|
| 5087 | SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not ");
|
| 5088 | #StdOut
|
| 5089 | path.setFillType(SkPath::kWinding_FillType);
|
| 5090 | path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
|
| 5091 | path.lineTo(SkBits2Float(0x3f5b6db7), SkBits2Float(0x3f2aaaab)); // 0.857143f, 0.666667f
|
| 5092 | path is equal to copy
|
| 5093 | ##
|
| 5094 | ##
|
| 5095 |
|
| 5096 | #SeeAlso dump SkRect::dumpHex() SkRRect::dumpHex() writeToMemory
|
| 5097 |
|
| 5098 | ##
|
| 5099 |
|
| 5100 | # ------------------------------------------------------------------------------
|
| 5101 |
|
| 5102 | #Method size_t writeToMemory(void* buffer) const
|
| 5103 |
|
| 5104 | Write Path to buffer, returning the number of bytes written.
|
| 5105 | Pass nullptr to obtain the storage size.
|
| 5106 |
|
| 5107 | writeToMemory writes Fill_Type, Verb_Array, Point_Array, Conic_Weight, and
|
| 5108 | additionally writes computed information like Convexity and bounds.
|
| 5109 |
|
| 5110 | writeToMemory should only be used in concert with readFromMemory.
|
| 5111 | The format used for Path in memory is not guaranteed.
|
| 5112 |
|
| 5113 | #Param buffer storage for Path; may be nullptr. ##
|
| 5114 |
|
| 5115 | #Return size of storage required for Path; always a multiple of 4. ##
|
| 5116 |
|
| 5117 | #Example
|
| 5118 | void draw(SkCanvas* canvas) {
|
| 5119 | SkPath path, copy;
|
| 5120 | path.lineTo(6.f / 7, 2.f / 3);
|
| 5121 | size_t size = path.writeToMemory(nullptr);
|
| 5122 | SkTDArray<char> storage;
|
| 5123 | storage.setCount(size);
|
| 5124 | path.writeToMemory(storage.begin());
|
| 5125 | copy.readFromMemory(storage.begin(), size);
|
| 5126 | SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not ");
|
| 5127 | }
|
| 5128 | ##
|
| 5129 |
|
| 5130 | #SeeAlso readFromMemory dump dumpHex
|
| 5131 |
|
| 5132 | ##
|
| 5133 |
|
| 5134 | # ------------------------------------------------------------------------------
|
| 5135 |
|
| 5136 | #Method size_t readFromMemory(const void* buffer, size_t length)
|
| 5137 |
|
| 5138 | Initializes Path from buffer of size length. Returns zero if the buffer is
|
| 5139 | data is inconsistent, or the length is too small.
|
| 5140 |
|
| 5141 | readFromMemory reads Fill_Type, Verb_Array, Point_Array, Conic_Weight, and
|
| 5142 | additionally reads computed information like Convexity and bounds.
|
| 5143 |
|
| 5144 | readFromMemory should only be used in concert with writeToMemory.
|
| 5145 | The format used for Path in memory is not guaranteed.
|
| 5146 |
|
| 5147 | #Param buffer storage for Path. ##
|
| 5148 | #Param length buffer size in bytes; must be multiple of 4. ##
|
| 5149 |
|
| 5150 | #Return number of bytes read, or zero on failure. ##
|
| 5151 |
|
| 5152 | #Example
|
| 5153 | void draw(SkCanvas* canvas) {
|
| 5154 | SkPath path, copy;
|
| 5155 | path.lineTo(6.f / 7, 2.f / 3);
|
| 5156 | size_t size = path.writeToMemory(nullptr);
|
| 5157 | SkTDArray<char> storage;
|
| 5158 | storage.setCount(size);
|
| 5159 | path.writeToMemory(storage.begin());
|
| 5160 | size_t wrongSize = size - 4;
|
| 5161 | size_t bytesRead = copy.readFromMemory(storage.begin(), wrongSize);
|
| 5162 | SkDebugf("length = %u; returned by readFromMemory = %u\n", wrongSize, bytesRead);
|
| 5163 | size_t largerSize = size + 4;
|
| 5164 | bytesRead = copy.readFromMemory(storage.begin(), largerSize);
|
| 5165 | SkDebugf("length = %u; returned by readFromMemory = %u\n", largerSize, bytesRead);
|
| 5166 | }
|
| 5167 | #StdOut
|
| 5168 | length = 60; returned by readFromMemory = 0
|
| 5169 | length = 68; returned by readFromMemory = 64
|
| 5170 | ##
|
| 5171 | ##
|
| 5172 |
|
| 5173 | #SeeAlso writeToMemory
|
| 5174 |
|
| 5175 | ##
|
| 5176 |
|
| 5177 | # ------------------------------------------------------------------------------
|
| 5178 | #Topic Generation_ID
|
| 5179 | #Alias Generation_IDs
|
| 5180 |
|
| 5181 | Generation_ID provides a quick way to check if Verb_Array, Point_Array, or
|
| 5182 | Conic_Weight has changed. Generation_ID is not a hash; identical Paths will
|
| 5183 | not necessarily have matching Generation_IDs.
|
| 5184 |
|
| 5185 | Empty Paths have a Generation_ID of one.
|
| 5186 |
|
| 5187 | #Method uint32_t getGenerationID() const
|
| 5188 |
|
| 5189 | Returns a non-zero, globally unique value. A different value is returned
|
| 5190 | if Verb_Array, Point_Array, or Conic_Weight changes.
|
| 5191 |
|
| 5192 | Setting Fill_Type does not change Generation_ID.
|
| 5193 |
|
| 5194 | Each time the path is modified, a different Generation_ID will be returned.
|
| 5195 |
|
| 5196 | #Bug 1762
|
| 5197 | Fill_Type does affect Generation_ID on Android framework.
|
| 5198 | ##
|
| 5199 |
|
| 5200 | #Return non-zero, globally unique value. ##
|
| 5201 |
|
| 5202 | #Example
|
| 5203 | SkPath path;
|
| 5204 | SkDebugf("empty genID = %u\n", path.getGenerationID());
|
| 5205 | path.lineTo(1, 2);
|
| 5206 | SkDebugf("1st lineTo genID = %u\n", path.getGenerationID());
|
| 5207 | path.rewind();
|
| 5208 | SkDebugf("empty genID = %u\n", path.getGenerationID());
|
| 5209 | path.lineTo(1, 2);
|
| 5210 | SkDebugf("2nd lineTo genID = %u\n", path.getGenerationID());
|
| 5211 | #StdOut
|
| 5212 | empty genID = 1
|
| 5213 | 1st lineTo genID = 2
|
| 5214 | empty genID = 1
|
| 5215 | 2nd lineTo genID = 3
|
| 5216 | ##
|
| 5217 | ##
|
| 5218 |
|
| 5219 | #SeeAlso operator==(const SkPath& a, const SkPath& b)
|
| 5220 |
|
| 5221 | ##
|
| 5222 |
|
| 5223 | #Topic ##
|
| 5224 |
|
| 5225 | # ------------------------------------------------------------------------------
|
| 5226 |
|
| 5227 | #Method void validate() const
|
| 5228 |
|
| 5229 | Debugging check to see if Path data is consistent.
|
| 5230 | Not currently maintained.
|
| 5231 |
|
| 5232 | #NoExample
|
| 5233 | ##
|
| 5234 |
|
| 5235 | ##
|
| 5236 |
|
| 5237 | # ------------------------------------------------------------------------------
|
| 5238 |
|
| 5239 | #Method void experimentalValidateRef() const
|
| 5240 |
|
| 5241 | #Private
|
| 5242 | Debugging check to see if Path data is consistent.
|
| 5243 | Not ready for public use.
|
| 5244 | ##
|
| 5245 |
|
| 5246 | ##
|
| 5247 |
|
| 5248 | # ------------------------------------------------------------------------------
|
| 5249 |
|
| 5250 | #Class Iter |
| 5251 | |
| 5252 | Iterates through Verb_Array, and associated Point_Array and Conic_Weight. |
| 5253 | Provides options to treat open Contours as closed, and to ignore |
| 5254 | degenerate data. |
| 5255 | |
| 5256 | #Example |
| 5257 | #Height 128 |
| 5258 | #Description |
| 5259 | Ignoring the actual Verbs and replacing them with quads rounds the |
| 5260 | path of the glyph. |
| 5261 | ## |
| 5262 | void draw(SkCanvas* canvas) {
|
| 5263 | SkPaint paint;
|
| 5264 | paint.setAntiAlias(true);
|
| 5265 | paint.setTextSize(256);
|
| 5266 | SkPath asterisk, path;
|
| 5267 | paint.getTextPath("*", 1, 50, 192, &asterisk);
|
| 5268 | SkPath::Iter iter(asterisk, true);
|
| 5269 | SkPoint start[4], pts[4];
|
| 5270 | iter.next(start); // skip moveTo
|
| 5271 | iter.next(start); // first quadTo
|
| 5272 | path.moveTo((start[0] + start[1]) * 0.5f);
|
| 5273 | while (SkPath::kClose_Verb != iter.next(pts)) {
|
| 5274 | path.quadTo(pts[0], (pts[0] + pts[1]) * 0.5f);
|
| 5275 | }
|
| 5276 | path.quadTo(start[0], (start[0] + start[1]) * 0.5f);
|
| 5277 | canvas->drawPath(path, paint);
|
| 5278 | } |
| 5279 | ## |
| 5280 | |
| 5281 | #SeeAlso RawIter |
| 5282 | |
| 5283 | #Method Iter() |
| 5284 | |
| 5285 | Initializes Iter with an empty Path. next() on Iter returns kDone_Verb. |
| 5286 | Call setPath to initialize Iter at a later time. |
| 5287 | |
| 5288 | #Return Iter of empty Path. ## |
| 5289 | |
| 5290 | #Example |
| 5291 | void draw(SkCanvas* canvas) {
|
| 5292 | SkPath::Iter iter;
|
| 5293 | SkPoint points[4];
|
| 5294 | SkDebugf("iter is " "%s" "done\n", SkPath::kDone_Verb == iter.next(points) ? "" : "not ");
|
| 5295 | SkPath path;
|
| 5296 | iter.setPath(path, false);
|
| 5297 | SkDebugf("iter is " "%s" "done\n", SkPath::kDone_Verb == iter.next(points) ? "" : "not ");
|
| 5298 | } |
| 5299 | #StdOut
|
| 5300 | iter is done
|
| 5301 | iter is done
|
| 5302 | ##
|
| 5303 | ## |
| 5304 | |
| 5305 | #SeeAlso setPath |
| 5306 | |
| 5307 | ## |
| 5308 | |
| 5309 | #Method Iter(const SkPath& path, bool forceClose) |
| 5310 | |
| 5311 | Sets Iter to return elements of Verb_Array, Point_Array, and Conic_Weight in path. |
| 5312 | If forceClose is true, Iter will add kLine_Verb and kClose_Verb after each |
| 5313 | open Contour. path is not altered. |
| 5314 | |
| 5315 | #Param path Path to iterate. ## |
| 5316 | #Param forceClose true if open Contours generate kClose_Verb. ## |
| 5317 | |
| 5318 | #Return Iter of path. ## |
| 5319 | |
| 5320 | #Example |
| 5321 | void draw(SkCanvas* canvas) {
|
| 5322 | auto debugster = [](const char* prefix, SkPath::Iter& iter) -> void {
|
| 5323 | SkDebugf("%s:\n", prefix);
|
| 5324 | const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
|
| 5325 | const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
| 5326 | SkPath::Verb verb;
|
| 5327 | do {
|
| 5328 | SkPoint points[4];
|
| 5329 | verb = iter.next(points);
|
| 5330 | SkDebugf("k%s_Verb ", verbStr[(int) verb]);
|
| 5331 | for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
| 5332 | SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
|
| 5333 | }
|
| 5334 | if (SkPath::kConic_Verb == verb) {
|
| 5335 | SkDebugf("weight = %g", iter.conicWeight());
|
| 5336 | }
|
| 5337 | SkDebugf("\n");
|
| 5338 | } while (SkPath::kDone_Verb != verb);
|
| 5339 | SkDebugf("\n");
|
| 5340 | };
|
| 5341 |
|
| 5342 | SkPath path;
|
| 5343 | path.quadTo(10, 20, 30, 40);
|
| 5344 | SkPath::Iter openIter(path, false);
|
| 5345 | debugster("open", openIter);
|
| 5346 | SkPath::Iter closedIter(path, true);
|
| 5347 | debugster("closed", closedIter);
|
| 5348 | } |
| 5349 | #StdOut |
| 5350 | open: |
| 5351 | kMove_Verb {0, 0},
|
| 5352 | kQuad_Verb {0, 0}, {10, 20}, {30, 40},
|
| 5353 | kDone_Verb
|
| 5354 |
|
| 5355 | closed:
|
| 5356 | kMove_Verb {0, 0},
|
| 5357 | kQuad_Verb {0, 0}, {10, 20}, {30, 40},
|
| 5358 | kLine_Verb {30, 40}, {0, 0},
|
| 5359 | kClose_Verb {0, 0},
|
| 5360 | kDone_Verb |
| 5361 | ## |
| 5362 | ## |
| 5363 | |
| 5364 | #SeeAlso setPath |
| 5365 | |
| 5366 | ## |
| 5367 | |
| 5368 | #Method void setPath(const SkPath& path, bool forceClose) |
| 5369 | |
| 5370 | Sets Iter to return elements of Verb_Array, Point_Array, and Conic_Weight in path. |
| 5371 | If forceClose is true, Iter will add kLine_Verb and kClose_Verb after each |
| 5372 | open Contour. path is not altered. |
| 5373 | |
| 5374 | #Param path Path to iterate. ## |
| 5375 | #Param forceClose true if open Contours generate kClose_Verb. ## |
| 5376 | |
| 5377 | #Example |
| 5378 | void draw(SkCanvas* canvas) {
|
| 5379 | auto debugster = [](const char* prefix, SkPath::Iter& iter) -> void {
|
| 5380 | SkDebugf("%s:\n", prefix);
|
| 5381 | const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
|
| 5382 | const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
| 5383 | SkPath::Verb verb;
|
| 5384 | do {
|
| 5385 | SkPoint points[4];
|
| 5386 | verb = iter.next(points);
|
| 5387 | SkDebugf("k%s_Verb ", verbStr[(int) verb]);
|
| 5388 | for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
| 5389 | SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
|
| 5390 | }
|
| 5391 | if (SkPath::kConic_Verb == verb) {
|
| 5392 | SkDebugf("weight = %g", iter.conicWeight());
|
| 5393 | }
|
| 5394 | SkDebugf("\n");
|
| 5395 | } while (SkPath::kDone_Verb != verb);
|
| 5396 | SkDebugf("\n");
|
| 5397 | };
|
| 5398 |
|
| 5399 | SkPath path;
|
| 5400 | path.quadTo(10, 20, 30, 40);
|
| 5401 | SkPath::Iter iter(path, false);
|
| 5402 | debugster("quad open", iter);
|
| 5403 | SkPath path2;
|
| 5404 | path2.conicTo(1, 2, 3, 4, .5f);
|
| 5405 | iter.setPath(path2, true);
|
| 5406 | debugster("conic closed", iter);
|
| 5407 | } |
| 5408 | #StdOut |
| 5409 | quad open:
|
| 5410 | kMove_Verb {0, 0},
|
| 5411 | kQuad_Verb {0, 0}, {10, 20}, {30, 40},
|
| 5412 | kDone_Verb
|
| 5413 |
|
| 5414 | conic closed:
|
| 5415 | kMove_Verb {0, 0},
|
| 5416 | kConic_Verb {0, 0}, {1, 2}, {3, 4}, weight = 0.5
|
| 5417 | kLine_Verb {3, 4}, {0, 0},
|
| 5418 | kClose_Verb {0, 0},
|
| 5419 | kDone_Verb |
| 5420 | ## |
| 5421 | ## |
| 5422 | |
| 5423 | #SeeAlso Iter(const SkPath& path, bool forceClose) |
| 5424 | |
| 5425 | ## |
| 5426 | |
| 5427 | #Method Verb next(SkPoint pts[4], bool doConsumeDegenerates = true, bool exact = false) |
| 5428 | |
| 5429 | Returns next Verb in Verb_Array, and advances Iter. |
| 5430 | When Verb_Array is exhausted, returns kDone_Verb. |
| 5431 | Zero to four Points are stored in pts, depending on the returned Verb. |
| 5432 | If doConsumeDegenerates is true, skip consecutive kMove_Verb entries, returning |
| 5433 | only the last in the series; and skip very small Lines, Quads, and Conics; and |
| 5434 | skip kClose_Verb following kMove_Verb. |
| 5435 | if doConsumeDegenerates is true and exact is true, only skip Lines, Quads, and |
| 5436 | Conics with zero lengths. |
| 5437 | |
| 5438 | #Param pts Storage for Point data describing returned Verb. ## |
| 5439 | #Param doConsumeDegenerates If true, skip degenerate Verbs. ## |
| 5440 | #Param exact If true, skip zero length curves. Has no effect if doConsumeDegenerates |
| 5441 | is false. |
| 5442 | ## |
| 5443 | |
| 5444 | #Return next Verb from Verb_Array. ## |
| 5445 | |
| 5446 | #Example |
| 5447 | #Description |
| 5448 | skip degenerate skips the first in a kMove_Verb pair, the kMove_Verb |
| 5449 | followed by the kClose_Verb, the zero length Line and the very small Line. |
| 5450 | |
| 5451 | skip degenerate if exact skips the same as skip degenerate, but shows |
| 5452 | the very small Line. |
| 5453 | |
| 5454 | skip none shows all of the Verbs and Points in Path. |
| 5455 | ## |
| 5456 | void draw(SkCanvas* canvas) {
|
| 5457 | auto debugster = [](const char* prefix, const SkPath& path, bool degen, bool exact) -> void {
|
| 5458 | SkPath::Iter iter(path, false);
|
| 5459 | SkDebugf("%s:\n", prefix);
|
| 5460 | const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
|
| 5461 | const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
| 5462 | SkPath::Verb verb;
|
| 5463 | do {
|
| 5464 | SkPoint points[4];
|
| 5465 | verb = iter.next(points, degen, exact);
|
| 5466 | SkDebugf("k%s_Verb ", verbStr[(int) verb]);
|
| 5467 | for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
| 5468 | SkDebugf("{%1.8g, %1.8g}, ", points[i].fX, points[i].fY);
|
| 5469 | }
|
| 5470 | SkDebugf("\n");
|
| 5471 | } while (SkPath::kDone_Verb != verb);
|
| 5472 | SkDebugf("\n");
|
| 5473 | };
|
| 5474 |
|
| 5475 | SkPath path;
|
| 5476 | path.moveTo(10, 10);
|
| 5477 | path.moveTo(20, 20);
|
| 5478 | path.quadTo(10, 20, 30, 40);
|
| 5479 | path.moveTo(1, 1);
|
| 5480 | path.close();
|
| 5481 | path.moveTo(30, 30);
|
| 5482 | path.lineTo(30, 30);
|
| 5483 | path.moveTo(30, 30);
|
| 5484 | path.lineTo(30.00001f, 30);
|
| 5485 | debugster("skip degenerate", path, true, false);
|
| 5486 | debugster("skip degenerate if exact", path, true, true);
|
| 5487 | debugster("skip none", path, false, false);
|
| 5488 | } |
| 5489 | #StdOut |
| 5490 | skip degenerate:
|
| 5491 | kMove_Verb {20, 20},
|
| 5492 | kQuad_Verb {20, 20}, {10, 20}, {30, 40},
|
| 5493 | kDone_Verb
|
| 5494 |
|
| 5495 | skip degenerate if exact:
|
| 5496 | kMove_Verb {20, 20},
|
| 5497 | kQuad_Verb {20, 20}, {10, 20}, {30, 40},
|
| 5498 | kMove_Verb {30, 30},
|
| 5499 | kLine_Verb {30, 30}, {30.00001, 30},
|
| 5500 | kDone_Verb
|
| 5501 |
|
| 5502 | skip none:
|
| 5503 | kMove_Verb {10, 10},
|
| 5504 | kMove_Verb {20, 20},
|
| 5505 | kQuad_Verb {20, 20}, {10, 20}, {30, 40},
|
| 5506 | kMove_Verb {1, 1},
|
| 5507 | kClose_Verb {1, 1},
|
| 5508 | kMove_Verb {30, 30},
|
| 5509 | kLine_Verb {30, 30}, {30, 30},
|
| 5510 | kMove_Verb {30, 30},
|
| 5511 | kLine_Verb {30, 30}, {30.00001, 30},
|
| 5512 | kDone_Verb
|
| 5513 | ## |
| 5514 | ## |
| 5515 | |
| 5516 | #SeeAlso Verb IsLineDegenerate IsCubicDegenerate IsQuadDegenerate |
| 5517 | |
| 5518 | ## |
| 5519 | |
| 5520 | #Method SkScalar conicWeight() const |
| 5521 | |
| 5522 | Returns Conic_Weight if next() returned kConic_Verb. |
| 5523 | |
| 5524 | If next() has not been called, or next() did not return kConic_Verb, |
| 5525 | result is undefined. |
| 5526 | |
| 5527 | #Return Conic_Weight for Conic Points returned by next(). ## |
| 5528 | |
| 5529 | #Example |
| 5530 | void draw(SkCanvas* canvas) {
|
| 5531 | SkPath path;
|
| 5532 | path.conicTo(1, 2, 3, 4, .5f);
|
| 5533 | SkPath::Iter iter(path, false);
|
| 5534 | SkPoint p[4];
|
| 5535 | SkDebugf("first verb is " "%s" "move\n", SkPath::kMove_Verb == iter.next(p) ? "" : "not ");
|
| 5536 | SkDebugf("next verb is " "%s" "conic\n", SkPath::kConic_Verb == iter.next(p) ? "" : "not ");
|
| 5537 | SkDebugf("conic points: {%g,%g}, {%g,%g}, {%g,%g}\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY,
|
| 5538 | p[2].fX, p[2].fY);
|
| 5539 | SkDebugf("conic weight: %g\n", iter.conicWeight());
|
| 5540 | } |
| 5541 | #StdOut |
| 5542 | first verb is move
|
| 5543 | next verb is conic
|
| 5544 | conic points: {0,0}, {1,2}, {3,4}
|
| 5545 | conic weight: 0.5 |
| 5546 | ## |
| 5547 | ## |
| 5548 | |
| 5549 | #SeeAlso Conic_Weight |
| 5550 | |
| 5551 | ## |
| 5552 | |
| 5553 | #Method bool isCloseLine() const |
| 5554 | |
| 5555 | Returns true if last kLine_Verb returned by next() was generated |
| 5556 | by kClose_Verb. When true, the end point returned by next() is |
| 5557 | also the start point of Contour. |
| 5558 | |
| 5559 | If next() has not been called, or next() did not return kLine_Verb, |
| 5560 | result is undefined. |
| 5561 | |
| 5562 | #Return true if last kLine_Verb was generated by kClose_Verb. ## |
| 5563 | |
| 5564 | #Example |
| 5565 | void draw(SkCanvas* canvas) {
|
| 5566 | SkPath path;
|
| 5567 | path.moveTo(6, 7);
|
| 5568 | path.conicTo(1, 2, 3, 4, .5f);
|
| 5569 | path.close();
|
| 5570 | SkPath::Iter iter(path, false);
|
| 5571 | SkPoint p[4];
|
| 5572 | SkDebugf("1st verb is " "%s" "move\n", SkPath::kMove_Verb == iter.next(p) ? "" : "not ");
|
| 5573 | SkDebugf("moveTo point: {%g,%g}\n", p[0].fX, p[0].fY);
|
| 5574 | SkDebugf("2nd verb is " "%s" "conic\n", SkPath::kConic_Verb == iter.next(p) ? "" : "not ");
|
| 5575 | SkDebugf("3rd verb is " "%s" "line\n", SkPath::kLine_Verb == iter.next(p) ? "" : "not ");
|
| 5576 | SkDebugf("line points: {%g,%g}, {%g,%g}\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY);
|
| 5577 | SkDebugf("line " "%s" "generated by close\n", iter.isCloseLine() ? "" : "not ");
|
| 5578 | SkDebugf("4th verb is " "%s" "close\n", SkPath::kClose_Verb == iter.next(p) ? "" : "not ");
|
| 5579 | } |
| 5580 | #StdOut |
| 5581 | 1st verb is move
|
| 5582 | moveTo point: {6,7}
|
| 5583 | 2nd verb is conic
|
| 5584 | 3rd verb is line
|
| 5585 | line points: {3,4}, {6,7}
|
| 5586 | line generated by close
|
| 5587 | 4th verb is close |
| 5588 | ## |
| 5589 | ## |
| 5590 | |
| 5591 | #SeeAlso close() |
| 5592 | ## |
| 5593 | |
| 5594 | #Method bool isClosedContour() const |
| 5595 | |
| 5596 | Returns true if subsequent calls to next() return kClose_Verb before returning |
| 5597 | kMove_Verb. if true, Contour Iter is processing may end with kClose_Verb, or |
| 5598 | Iter may have been initialized with force close set to true. |
| 5599 | |
| 5600 | #Return true if Contour is closed. ## |
| 5601 | |
| 5602 | #Example |
| 5603 | void draw(SkCanvas* canvas) {
|
| 5604 | for (bool forceClose : { false, true } ) {
|
| 5605 | SkPath path;
|
| 5606 | path.conicTo(1, 2, 3, 4, .5f);
|
| 5607 | SkPath::Iter iter(path, forceClose);
|
| 5608 | SkDebugf("without close(), forceClose is %s: isClosedContour returns %s\n",
|
| 5609 | forceClose ? "true " : "false", iter.isClosedContour() ? "true" : "false");
|
| 5610 | path.close();
|
| 5611 | iter.setPath(path, forceClose);
|
| 5612 | SkDebugf("with close(), forceClose is %s: isClosedContour returns %s\n",
|
| 5613 | forceClose ? "true " : "false", iter.isClosedContour() ? "true" : "false");
|
| 5614 | }
|
| 5615 | } |
| 5616 | #StdOut |
| 5617 | without close(), forceClose is false: isClosedContour returns false
|
| 5618 | with close(), forceClose is false: isClosedContour returns true
|
| 5619 | without close(), forceClose is true : isClosedContour returns true
|
| 5620 | with close(), forceClose is true : isClosedContour returns true |
| 5621 | ## |
| 5622 | ## |
| 5623 | |
| 5624 | #SeeAlso Iter(const SkPath& path, bool forceClose) |
| 5625 | |
| 5626 | ## |
| 5627 |
|
| 5628 | #Class Iter ##
|
| 5629 |
|
| 5630 | #Class RawIter |
| 5631 | |
| 5632 | Iterates through Verb_Array, and associated Point_Array and Conic_Weight. |
| 5633 | Verb_Array, Point_Array, and Conic_Weight are returned unaltered. |
| 5634 | |
| 5635 | #Method RawIter() |
| 5636 | |
| 5637 | Initializes RawIter with an empty Path. next() on RawIter returns kDone_Verb. |
| 5638 | Call setPath to initialize Iter at a later time. |
| 5639 | |
| 5640 | #Return RawIter of empty Path. ##
|
| 5641 |
|
| 5642 | #NoExample
|
| 5643 | ##
|
| 5644 | ##
|
| 5645 | |
| 5646 | #Method RawIter(const SkPath& path) |
| 5647 | |
| 5648 | |
| 5649 | Sets RawIter to return elements of Verb_Array, Point_Array, and Conic_Weight in path. |
| 5650 | |
| 5651 | #Param path Path to iterate. ## |
| 5652 | |
| 5653 | #Return RawIter of path. ## |
| 5654 |
|
| 5655 | #NoExample
|
| 5656 | ##
|
| 5657 | ##
|
| 5658 | |
| 5659 | #Method void setPath(const SkPath& path) |
| 5660 | |
| 5661 | Sets Iter to return elements of Verb_Array, Point_Array, and Conic_Weight in path. |
| 5662 | |
| 5663 | #Param path Path to iterate. ## |
| 5664 |
|
| 5665 | #NoExample
|
| 5666 | ##
|
| 5667 | ##
|
| 5668 | |
| 5669 | #Method Verb next(SkPoint pts[4]) |
| 5670 | |
| 5671 | Returns next Verb in Verb_Array, and advances RawIter. |
| 5672 | When Verb_Array is exhausted, returns kDone_Verb. |
| 5673 | Zero to four Points are stored in pts, depending on the returned Verb. |
| 5674 | |
| 5675 | #Param pts Storage for Point data describing returned Verb. ## |
| 5676 | |
| 5677 | #Return next Verb from Verb_Array. ## |
| 5678 | |
| 5679 | #Example |
| 5680 | void draw(SkCanvas* canvas) {
|
| 5681 | SkPath path;
|
| 5682 | path.moveTo(50, 60);
|
| 5683 | path.quadTo(10, 20, 30, 40);
|
| 5684 | path.close();
|
| 5685 | path.lineTo(30, 30);
|
| 5686 | path.conicTo(1, 2, 3, 4, .5f);
|
| 5687 | path.cubicTo(-1, -2, -3, -4, -5, -6);
|
| 5688 | SkPath::RawIter iter(path);
|
| 5689 | const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
|
| 5690 | const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
| 5691 | SkPath::Verb verb;
|
| 5692 | do {
|
| 5693 | SkPoint points[4];
|
| 5694 | verb = iter.next(points);
|
| 5695 | SkDebugf("k%s_Verb ", verbStr[(int) verb]);
|
| 5696 | for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
| 5697 | SkDebugf("{%1.8g, %1.8g}, ", points[i].fX, points[i].fY);
|
| 5698 | }
|
| 5699 | if (SkPath::kConic_Verb == verb) {
|
| 5700 | SkDebugf("weight = %g", iter.conicWeight());
|
| 5701 | }
|
| 5702 | SkDebugf("\n");
|
| 5703 | } while (SkPath::kDone_Verb != verb);
|
| 5704 | } |
| 5705 | #StdOut |
| 5706 | kMove_Verb {50, 60},
|
| 5707 | kQuad_Verb {50, 60}, {10, 20}, {30, 40},
|
| 5708 | kClose_Verb {50, 60},
|
| 5709 | kMove_Verb {50, 60},
|
| 5710 | kLine_Verb {50, 60}, {30, 30},
|
| 5711 | kConic_Verb {30, 30}, {1, 2}, {3, 4}, weight = 0.5
|
| 5712 | kCubic_Verb {3, 4}, {-1, -2}, {-3, -4}, {-5, -6},
|
| 5713 | kDone_Verb |
| 5714 | ## |
| 5715 | ## |
| 5716 | |
| 5717 | #SeeAlso peek() |
| 5718 | |
| 5719 | ##
|
| 5720 | |
| 5721 | #Method Verb peek() const |
| 5722 | |
| 5723 | Returns next Verb, but does not advance RawIter. |
| 5724 | |
| 5725 | #Return next Verb from Verb_Array. ## |
| 5726 | |
| 5727 | #Example |
| 5728 | SkPath path;
|
| 5729 | path.quadTo(10, 20, 30, 40);
|
| 5730 | path.conicTo(1, 2, 3, 4, .5f);
|
| 5731 | path.cubicTo(1, 2, 3, 4, .5, 6);
|
| 5732 | SkPath::RawIter iter(path);
|
| 5733 | SkPath::Verb verb, peek = iter.peek();
|
| 5734 | const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
|
| 5735 | do {
|
| 5736 | SkPoint points[4];
|
| 5737 | verb = iter.next(points);
|
| 5738 | SkDebugf("peek %s %c= verb %s\n", verbStr[peek], peek == verb ? '=' : '!', verbStr[verb]);
|
| 5739 | peek = iter.peek();
|
| 5740 | } while (SkPath::kDone_Verb != verb); |
| 5741 | SkDebugf("peek %s %c= verb %s\n", verbStr[peek], peek == verb ? '=' : '!', verbStr[verb]);
|
| 5742 | #StdOut
|
| 5743 | #Volatile
|
| 5744 | peek Move == verb Move
|
| 5745 | peek Quad == verb Quad
|
| 5746 | peek Conic == verb Conic
|
| 5747 | peek Cubic == verb Cubic
|
| 5748 | peek Done == verb Done
|
| 5749 | peek Done == verb Done
|
| 5750 | ##
|
| 5751 | ## |
| 5752 | |
| 5753 | #Bug 6832 |
| 5754 | StdOut isn't really volatile, it just produces the wrong result. |
| 5755 | A simple fix changes the output of hairlines and needs to be |
| 5756 | investigated to see if the change is correct or not. |
| 5757 | https://skia-review.googlesource.com/c/21340/ |
| 5758 | ## |
| 5759 | |
| 5760 | #SeeAlso next() |
| 5761 | |
| 5762 | ##
|
| 5763 | |
| 5764 | #Method SkScalar conicWeight() const
|
| 5765 |
|
| 5766 | Returns Conic_Weight if next() returned kConic_Verb. |
| 5767 | |
| 5768 | If next() has not been called, or next() did not return kConic_Verb, |
| 5769 | result is undefined. |
| 5770 |
|
| 5771 | #Return Conic_Weight for Conic Points returned by next(). ## |
| 5772 | |
| 5773 | #Example |
| 5774 | void draw(SkCanvas* canvas) {
|
| 5775 | SkPath path;
|
| 5776 | path.conicTo(1, 2, 3, 4, .5f);
|
| 5777 | SkPath::RawIter iter(path);
|
| 5778 | SkPoint p[4];
|
| 5779 | SkDebugf("first verb is " "%s" "move\n", SkPath::kMove_Verb == iter.next(p) ? "" : "not ");
|
| 5780 | SkDebugf("next verb is " "%s" "conic\n", SkPath::kConic_Verb == iter.next(p) ? "" : "not ");
|
| 5781 | SkDebugf("conic points: {%g,%g}, {%g,%g}, {%g,%g}\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY,
|
| 5782 | p[2].fX, p[2].fY);
|
| 5783 | SkDebugf("conic weight: %g\n", iter.conicWeight());
|
| 5784 | } |
| 5785 | #StdOut |
| 5786 | first verb is move
|
| 5787 | next verb is conic
|
| 5788 | conic points: {0,0}, {1,2}, {3,4}
|
| 5789 | conic weight: 0.5 |
| 5790 | ## |
| 5791 | ## |
| 5792 | |
| 5793 | #SeeAlso Conic_Weight |
| 5794 |
|
| 5795 | ##
|
| 5796 |
|
| 5797 | #Class RawIter ##
|
| 5798 |
|
| 5799 | #Class SkPath ##
|
| 5800 |
|
| 5801 | #Topic Path ##
|