| #Topic Path |
| #Alias Path_Reference ## |
| #Alias Paths ## |
| |
| Path contains Lines and Curves which can be stroked or filled. Contour is |
| composed of a series of connected Lines and Curves. Path may contain zero, |
| one, or more Contours. |
| Each Line and Curve are described by Verb, Points, and optional Conic_Weight. |
| |
| Each pair of connected Lines and Curves share common Point; for instance, Path |
| containing two connected Lines are described the Verb sequence: |
| SkPath::kMove_Verb, SkPath::kLine_Verb, SkPath::kLine_Verb; and a Point sequence |
| with three entries, sharing |
| the middle entry as the end of the first Line and the start of the second Line. |
| |
| Path components Arc, Rect, Round_Rect, Circle, and Oval are composed of |
| Lines and Curves with as many Verbs and Points required |
| for an exact description. Once added to Path, these components may lose their |
| identity; although Path can be inspected to determine if it describes a single |
| Rect, Oval, Round_Rect, and so on. |
| |
| #Example |
| #Height 192 |
| #Description |
| Path contains three Contours: Line, Circle, and Quad. Line is stroked but |
| not filled. Circle is stroked and filled; Circle stroke forms a loop. Quad |
| is stroked and filled, but since it is not closed, Quad does not stroke a loop. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| SkPath path; |
| path.moveTo(124, 108); |
| path.lineTo(172, 24); |
| path.addCircle(50, 50, 30); |
| path.moveTo(36, 148); |
| path.quadTo(66, 188, 120, 136); |
| canvas->drawPath(path, paint); |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setColor(SK_ColorBLUE); |
| paint.setStrokeWidth(3); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| Path contains a Fill_Type which determines whether overlapping Contours |
| form fills or holes. Fill_Type also determines whether area inside or outside |
| Lines and Curves is filled. |
| |
| #Example |
| #Height 192 |
| #Description |
| Path is drawn filled, then stroked, then stroked and filled. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| SkPath path; |
| path.moveTo(36, 48); |
| path.quadTo(66, 88, 120, 36); |
| canvas->drawPath(path, paint); |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setColor(SK_ColorBLUE); |
| paint.setStrokeWidth(8); |
| canvas->translate(0, 50); |
| canvas->drawPath(path, paint); |
| paint.setStyle(SkPaint::kStrokeAndFill_Style); |
| paint.setColor(SK_ColorRED); |
| canvas->translate(0, 50); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| Path contents are never shared. Copying Path by value effectively creates |
| a new Path independent of the original. Internally, the copy does not duplicate |
| its contents until it is edited, to reduce memory use and improve performance. |
| |
| #Subtopic Contour |
| #Alias Contours ## |
| #Line # loop of lines and curves ## |
| |
| Contour contains one or more Verbs, and as many Points as |
| are required to satisfy Verb_Array. First Verb in Path is always |
| SkPath::kMove_Verb; each SkPath::kMove_Verb that follows starts a new Contour. |
| |
| #Example |
| #Description |
| Each SkPath::moveTo starts a new Contour, and content after SkPath::close() |
| also starts a new Contour. Since SkPath::conicTo is not preceded by |
| SkPath::moveTo, the first Point of the third Contour starts at the last Point |
| of the second Contour. |
| ## |
| #Height 192 |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| canvas->drawString("1st contour", 150, 100, paint); |
| canvas->drawString("2nd contour", 130, 160, paint); |
| canvas->drawString("3rd contour", 40, 30, paint); |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPath path; |
| path.moveTo(124, 108); |
| path.lineTo(172, 24); |
| path.moveTo(36, 148); |
| path.quadTo(66, 188, 120, 136); |
| path.close(); |
| path.conicTo(70, 20, 110, 40, 0.6f); |
| canvas->drawPath(path, paint); |
| ## |
| |
| If final Verb in Contour is SkPath::kClose_Verb, Line connects Last_Point in |
| Contour with first Point. A closed Contour, stroked, draws |
| Paint_Stroke_Join at Last_Point and first Point. Without SkPath::kClose_Verb |
| as final Verb, Last_Point and first Point are not connected; Contour |
| remains open. An open Contour, stroked, draws Paint_Stroke_Cap at |
| Last_Point and first Point. |
| |
| #Example |
| #Height 160 |
| #Description |
| Path is drawn stroked, with an open Contour and a closed Contour. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setStrokeWidth(8); |
| SkPath path; |
| path.moveTo(36, 48); |
| path.quadTo(66, 88, 120, 36); |
| canvas->drawPath(path, paint); |
| path.close(); |
| canvas->translate(0, 50); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #Subtopic Zero_Length |
| #Alias Zero_Length_Contour ## |
| #Line # consideration when contour has no length ## |
| Contour length is distance traveled from first Point to Last_Point, |
| plus, if Contour is closed, distance from Last_Point to first Point. |
| Even if Contour length is zero, stroked Lines are drawn if Paint_Stroke_Cap |
| makes them visible. |
| |
| #Example |
| #Height 64 |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setStrokeWidth(8); |
| paint.setStrokeCap(SkPaint::kRound_Cap); |
| SkPath path; |
| path.moveTo(36, 48); |
| path.lineTo(36, 48); |
| canvas->drawPath(path, paint); |
| path.reset(); |
| paint.setStrokeCap(SkPaint::kSquare_Cap); |
| path.moveTo(56, 48); |
| path.close(); |
| canvas->drawPath(path, paint); |
| ## |
| |
| #Subtopic Zero_Length ## |
| |
| #Subtopic Contour ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Class SkPath |
| |
| Paths contain geometry. Paths may be empty, or contain one or more Verbs that |
| outline a figure. Path always starts with a move verb to a Cartesian_Coordinate, |
| and may be followed by additional verbs that add lines or curves. |
| Adding a close verb makes the geometry into a continuous loop, a closed contour. |
| Paths may contain any number of contours, each beginning with a move verb. |
| |
| Path contours may contain only a move verb, or may also contain lines, |
| Quadratic_Beziers, Conics, and Cubic_Beziers. Path contours may be open or |
| closed. |
| |
| When used to draw a filled area, Path describes whether the fill is inside or |
| outside the geometry. Path also describes the winding rule used to fill |
| overlapping contours. |
| |
| Internally, Path lazily computes metrics likes bounds and convexity. Call |
| SkPath::updateBoundsCache to make Path thread safe. |
| |
| #Subtopic Overview |
| #Populate |
| ## |
| |
| #Subtopic Related_Function |
| #Populate |
| ## |
| |
| #Subtopic Constant |
| #Populate |
| ## |
| |
| #Subtopic Class |
| #Populate |
| ## |
| |
| #Subtopic Constructor |
| #Populate |
| ## |
| |
| #Subtopic Operator |
| #Populate |
| ## |
| |
| #Subtopic Member_Function |
| #Populate |
| ## |
| |
| #Subtopic Verb |
| #Alias Verbs ## |
| #Line # line and curve type ## |
| #Enum Verb |
| #Line # controls how Path Points are interpreted ## |
| |
| #Code |
| enum Verb { |
| kMove_Verb, |
| kLine_Verb, |
| kQuad_Verb, |
| kConic_Verb, |
| kCubic_Verb, |
| kClose_Verb, |
| kDone_Verb, |
| }; |
| ## |
| |
| Verb instructs Path how to interpret one or more Point and optional Conic_Weight; |
| manage Contour, and terminate Path. |
| |
| #Const kMove_Verb 0 |
| #Line # starts new Contour at next Point ## |
| Consecutive kMove_Verb are preserved but all but the last kMove_Verb is |
| ignored. kMove_Verb after other Verbs implicitly closes the previous Contour |
| if SkPaint::kFill_Style is set when drawn; otherwise, stroke is drawn open. |
| kMove_Verb as the last Verb is preserved but ignored. |
| ## |
| #Const kLine_Verb 1 |
| #Line # adds Line from Last_Point to next Point ## |
| Line is a straight segment from Point to Point. Consecutive kLine_Verb |
| extend Contour. kLine_Verb at same position as prior kMove_Verb is |
| preserved, and draws Point if SkPaint::kStroke_Style is set, and |
| SkPaint::Cap is SkPaint::kSquare_Cap or SkPaint::kRound_Cap. kLine_Verb |
| at same position as prior line or curve Verb is preserved but is ignored. |
| ## |
| #Const kQuad_Verb 2 |
| #Line # adds Quad from Last_Point ## |
| Adds Quad from Last_Point, using control Point, and end Point. |
| Quad is a parabolic section within tangents from Last_Point to control Point, |
| and control Point to end Point. |
| ## |
| #Const kConic_Verb 3 |
| #Line # adds Conic from Last_Point ## |
| Adds Conic from Last_Point, using control Point, end Point, and Conic_Weight. |
| Conic is a elliptical, parabolic, or hyperbolic section within tangents |
| from Last_Point to control Point, and control Point to end Point, constrained |
| by Conic_Weight. Conic_Weight less than one is elliptical; equal to one is |
| parabolic (and identical to Quad); greater than one hyperbolic. |
| ## |
| #Const kCubic_Verb 4 |
| #Line # adds Cubic from Last_Point ## |
| Adds Cubic from Last_Point, using two control Points, and end Point. |
| Cubic is a third-order Bezier_Curve section within tangents from Last_Point |
| to first control Point, and from second control Point to end Point. |
| ## |
| #Const kClose_Verb 5 |
| #Line # closes Contour ## |
| Closes Contour, connecting Last_Point to kMove_Verb Point. Consecutive |
| kClose_Verb are preserved but only first has an effect. kClose_Verb after |
| kMove_Verb has no effect. |
| ## |
| #Const kDone_Verb 6 |
| #Line # terminates Path ## |
| Not in Verb_Array, but returned by Path iterator. |
| ## |
| |
| Each Verb has zero or more Points stored in Path. |
| Path iterator returns complete curve descriptions, duplicating shared Points |
| for consecutive entries. |
| |
| #Table |
| #Legend |
| # Verb # Allocated Points # Iterated Points # Weights ## |
| ## |
| # kMove_Verb # 1 # 1 # 0 ## |
| # kLine_Verb # 1 # 2 # 0 ## |
| # kQuad_Verb # 2 # 3 # 0 ## |
| # kConic_Verb # 2 # 3 # 1 ## |
| # kCubic_Verb # 3 # 4 # 0 ## |
| # kClose_Verb # 0 # 1 # 0 ## |
| # kDone_Verb # -- # 0 # 0 ## |
| ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPath path; |
| path.lineTo(20, 20); |
| path.quadTo(-10, -10, 30, 30); |
| path.close(); |
| path.cubicTo(1, 2, 3, 4, 5, 6); |
| path.conicTo(0, 0, 0, 0, 2); |
| uint8_t verbs[7]; |
| int count = path.getVerbs(verbs, (int) SK_ARRAY_COUNT(verbs)); |
| const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close" }; |
| SkDebugf("verb count: %d\nverbs: ", count); |
| for (int i = 0; i < count; ++i) { |
| SkDebugf("k%s_Verb ", verbStr[verbs[i]]); |
| } |
| SkDebugf("\n"); |
| } |
| #StdOut |
| verb count: 7 |
| verbs: kMove_Verb kLine_Verb kQuad_Verb kClose_Verb kMove_Verb kCubic_Verb kConic_Verb |
| ## |
| ## |
| |
| #Enum Verb ## |
| #Subtopic Verb ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Direction |
| #Line # contour orientation, clockwise or counterclockwise ## |
| #Alias Directions ## |
| |
| #Enum Direction |
| #Line # sets Contour clockwise or counterclockwise ## |
| |
| #Code |
| enum Direction { |
| kCW_Direction, |
| kCCW_Direction, |
| }; |
| ## |
| |
| Direction describes whether Contour is clockwise or counterclockwise. |
| When Path contains multiple overlapping Contours, Direction together with |
| Fill_Type determines whether overlaps are filled or form holes. |
| |
| Direction also determines how Contour is measured. For instance, dashing |
| measures along Path to determine where to start and stop stroke; Direction |
| will change dashed results as it steps clockwise or counterclockwise. |
| |
| Closed Contours like Rect, Round_Rect, Circle, and Oval added with |
| kCW_Direction travel clockwise; the same added with kCCW_Direction |
| travel counterclockwise. |
| |
| #Const kCW_Direction 0 |
| #Line # contour travels clockwise ## |
| ## |
| #Const kCCW_Direction 1 |
| #Line # contour travels counterclockwise ## |
| ## |
| |
| |
| #Example |
| #Height 100 |
| void draw(SkCanvas* canvas) { |
| const SkPoint arrow[] = { {40, -5}, {45, 0}, {40, 5} }; |
| const SkRect rect = {10, 10, 90, 90}; |
| SkPaint rectPaint; |
| rectPaint.setAntiAlias(true); |
| SkPaint textPaint(rectPaint); |
| textPaint.setTextAlign(SkPaint::kCenter_Align); |
| rectPaint.setStyle(SkPaint::kStroke_Style); |
| SkPaint arrowPaint(rectPaint); |
| SkPath arrowPath; |
| arrowPath.addPoly(arrow, SK_ARRAY_COUNT(arrow), true); |
| arrowPaint.setPathEffect(SkPath1DPathEffect::Make(arrowPath, 320, 0, |
| SkPath1DPathEffect::kRotate_Style)); |
| for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) { |
| canvas->drawRect(rect, rectPaint); |
| for (unsigned start : { 0, 1, 2, 3 } ) { |
| SkPath path; |
| path.addRect(rect, direction, start); |
| canvas->drawPath(path, arrowPaint); |
| } |
| canvas->drawString(SkPath::kCW_Direction == direction ? "CW" : "CCW", rect.centerX(), |
| rect.centerY(), textPaint); |
| canvas->translate(120, 0); |
| } |
| } |
| ## |
| |
| #SeeAlso arcTo rArcTo isRect isNestedFillRects addRect addOval |
| |
| #Enum Direction ## |
| #Subtopic Direction ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method SkPath() |
| |
| #Line # constructs with default values ## |
| By default, Path has no Verbs, no Points, and no Weights. |
| Fill_Type is set to kWinding_FillType. |
| |
| #Return empty Path ## |
| |
| #Example |
| SkPath path; |
| SkDebugf("path is " "%s" "empty", path.isEmpty() ? "" : "not "); |
| #StdOut |
| path is empty |
| ## |
| ## |
| |
| #SeeAlso reset rewind |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method SkPath(const SkPath& path) |
| |
| #Line # makes a shallow copy ## |
| Copy constructor makes two paths identical by value. Internally, path and |
| the returned result share pointer values. The underlying Verb_Array, Point_Array |
| and Weights are copied when modified. |
| |
| Creating a Path copy is very efficient and never allocates memory. |
| Paths are always copied by value from the interface; the underlying shared |
| pointers are not exposed. |
| |
| #Param path Path to copy by value ## |
| |
| #Return copy of Path ## |
| |
| #Example |
| #Description |
| Modifying one path does not effect another, even if they started as copies |
| of each other. |
| ## |
| SkPath path; |
| path.lineTo(20, 20); |
| SkPath path2(path); |
| path2.close(); |
| SkDebugf("path verbs: %d\n", path.countVerbs()); |
| SkDebugf("path2 verbs: %d\n", path2.countVerbs()); |
| path.reset(); |
| SkDebugf("after reset\n" "path verbs: %d\n", path.countVerbs()); |
| SkDebugf("path2 verbs: %d\n", path2.countVerbs()); |
| #StdOut |
| path verbs: 2 |
| path2 verbs: 3 |
| after reset |
| path verbs: 0 |
| path2 verbs: 3 |
| ## |
| ## |
| |
| #SeeAlso operator=(const SkPath& path) |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method ~SkPath() |
| |
| #Line # decreases Reference_Count of owned objects ## |
| Releases ownership of any shared data and deletes data if Path is sole owner. |
| |
| #Example |
| #Description |
| delete calls Path Destructor, but copy of original in path2 is unaffected. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPath* path = new SkPath(); |
| path->lineTo(20, 20); |
| SkPath path2(*path); |
| delete path; |
| SkDebugf("path2 is " "%s" "empty", path2.isEmpty() ? "" : "not "); |
| } |
| ## |
| |
| #SeeAlso SkPath() SkPath(const SkPath& path) operator=(const SkPath& path) |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method SkPath& operator=(const SkPath& path) |
| |
| #Line # makes a shallow copy ## |
| Path assignment makes two paths identical by value. Internally, assignment |
| shares pointer values. The underlying Verb_Array, Point_Array and Weights |
| are copied when modified. |
| |
| Copying Paths by assignment is very efficient and never allocates memory. |
| Paths are always copied by value from the interface; the underlying shared |
| pointers are not exposed. |
| |
| #Param path Verb_Array, Point_Array, Weights, and Fill_Type to copy ## |
| |
| #Return Path copied by value ## |
| |
| #Example |
| SkPath path1; |
| path1.addRect({10, 20, 30, 40}); |
| SkPath path2 = path1; |
| const SkRect& b1 = path1.getBounds(); |
| SkDebugf("path1 bounds = %g, %g, %g, %g\n", b1.fLeft, b1.fTop, b1.fRight, b1.fBottom); |
| const SkRect& b2 = path2.getBounds(); |
| SkDebugf("path2 bounds = %g, %g, %g, %g\n", b2.fLeft, b2.fTop, b2.fRight, b2.fBottom); |
| #StdOut |
| path1 bounds = 10, 20, 30, 40 |
| path2 bounds = 10, 20, 30, 40 |
| #StdOut ## |
| ## |
| |
| #SeeAlso swap() SkPath(const SkPath& path) |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool operator==(const SkPath& a, const SkPath& b) |
| |
| #Line # compares paths for equality ## |
| Compares a and b; returns true if Fill_Type, Verb_Array, Point_Array, and Weights |
| are equivalent. |
| |
| #Param a Path to compare ## |
| #Param b Path to compare ## |
| |
| #Return true if Path pair are equivalent ## |
| |
| #Example |
| #Description |
| Rewind removes Verb_Array but leaves storage; since storage is not compared, |
| Path pair are equivalent. |
| ## |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& a, const SkPath& b) -> void { |
| SkDebugf("%s one %c= two\n", prefix, a == b ? '=' : '!'); |
| }; |
| SkPath one; |
| SkPath two; |
| debugster("empty", one, two); |
| one.moveTo(0, 0); |
| debugster("moveTo", one, two); |
| one.rewind(); |
| debugster("rewind", one, two); |
| one.moveTo(0, 0); |
| one.reset(); |
| debugster("reset", one, two); |
| } |
| #StdOut |
| empty one == two |
| moveTo one != two |
| rewind one == two |
| reset one == two |
| ## |
| ## |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool operator!=(const SkPath& a, const SkPath& b) |
| |
| #Line # compares paths for inequality ## |
| Compares a and b; returns true if Fill_Type, Verb_Array, Point_Array, and Weights |
| are not equivalent. |
| |
| #Param a Path to compare ## |
| #Param b Path to compare ## |
| |
| #Return true if Path pair are not equivalent ## |
| |
| #Example |
| #Description |
| Path pair are equal though their convexity is not equal. |
| ## |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& a, const SkPath& b) -> void { |
| SkDebugf("%s one %c= two\n", prefix, a != b ? '!' : '='); |
| }; |
| SkPath one; |
| SkPath two; |
| debugster("empty", one, two); |
| one.addRect({10, 20, 30, 40}); |
| two.addRect({10, 20, 30, 40}); |
| debugster("addRect", one, two); |
| one.setConvexity(SkPath::kConcave_Convexity); |
| debugster("setConvexity", one, two); |
| SkDebugf("convexity %c=\n", one.getConvexity() == two.getConvexity() ? '=' : '!'); |
| } |
| #StdOut |
| empty one == two |
| addRect one == two |
| setConvexity one == two |
| convexity != |
| ## |
| ## |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Subtopic Property |
| #Populate |
| #Line # metrics and attributes ## |
| ## |
| |
| #Method bool isInterpolatable(const SkPath& compare) const |
| #In Property |
| #In Interpolate |
| #Line # returns if pair contains equal counts of Verb_Array and Weights ## |
| Return true if Paths contain equal Verbs and equal Weights. |
| If Paths contain one or more Conics, the Weights must match. |
| |
| conicTo may add different Verbs depending on Conic_Weight, so it is not |
| trivial to interpolate a pair of Paths containing Conics with different |
| Conic_Weight values. |
| |
| #Param compare Path to compare ## |
| |
| #Return true if Paths Verb_Array and Weights are equivalent ## |
| |
| #Example |
| SkPath path, path2; |
| path.moveTo(20, 20); |
| path.lineTo(40, 40); |
| path.lineTo(20, 20); |
| path.lineTo(40, 40); |
| path.close(); |
| path2.addRect({20, 20, 40, 40}); |
| SkDebugf("paths are " "%s" "interpolatable", path.isInterpolatable(path2) ? "" : "not "); |
| #StdOut |
| paths are interpolatable |
| ## |
| ## |
| |
| #SeeAlso isInterpolatable |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Subtopic Interpolate |
| #Populate |
| #Line # weighted average of Path pair ## |
| ## |
| |
| #Method bool interpolate(const SkPath& ending, SkScalar weight, SkPath* out) const |
| #In Interpolate |
| #Line # interpolates between Path pair ## |
| Interpolate between Paths with Point_Array of equal size. |
| Copy Verb_Array and Weights to out, and set out Point_Array to a weighted |
| average of this Point_Array and ending Point_Array, using the formula: |
| #Formula |
| (Path Point * weight) + ending Point * (1 - weight) |
| ## |
| . |
| |
| weight is most useful when between zero (ending Point_Array) and |
| one (this Point_Array); will work with values outside of this |
| range. |
| |
| interpolate() returns false and leaves out unchanged if Point_Array is not |
| the same size as ending Point_Array. Call isInterpolatable to check Path |
| compatibility prior to calling interpolate(). |
| |
| #Param ending Point_Array averaged with this Point_Array ## |
| #Param weight contribution of this Point_Array, and |
| one minus contribution of ending Point_Array |
| ## |
| #Param out Path replaced by interpolated averages ## |
| |
| #Return true if Paths contain same number of Points ## |
| |
| #Example |
| #Height 60 |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPath path, path2; |
| path.moveTo(20, 20); |
| path.lineTo(40, 40); |
| path.lineTo(20, 40); |
| path.lineTo(40, 20); |
| path.close(); |
| path2.addRect({20, 20, 40, 40}); |
| for (SkScalar i = 0; i <= 1; i += 1.f / 6) { |
| SkPath interp; |
| path.interpolate(path2, i, &interp); |
| canvas->drawPath(interp, paint); |
| canvas->translate(30, 0); |
| } |
| } |
| ## |
| |
| #SeeAlso isInterpolatable |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool unique() const |
| #Deprecated soon |
| Only valid for Android framework. |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Fill_Type |
| #Line # fill rule, normal and inverted ## |
| |
| #Enum FillType |
| #Line # sets winding rule and inverse fill ## |
| |
| #Code |
| enum FillType { |
| kWinding_FillType, |
| kEvenOdd_FillType, |
| kInverseWinding_FillType, |
| kInverseEvenOdd_FillType, |
| }; |
| ## |
| |
| Fill_Type selects the rule used to fill Path. Path set to kWinding_FillType |
| fills if the sum of Contour edges is not zero, where clockwise edges add one, and |
| counterclockwise edges subtract one. Path set to kEvenOdd_FillType fills if the |
| number of Contour edges is odd. Each Fill_Type has an inverse variant that |
| reverses the rule: |
| kInverseWinding_FillType fills where the sum of Contour edges is zero; |
| kInverseEvenOdd_FillType fills where the number of Contour edges is even. |
| |
| #Example |
| #Height 100 |
| #Description |
| The top row has two clockwise rectangles. The second row has one clockwise and |
| one counterclockwise rectangle. The even-odd variants draw the same. The |
| winding variants draw the top rectangle overlap, which has a winding of 2, the |
| same as the outer parts of the top rectangles, which have a winding of 1. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPath path; |
| path.addRect({10, 10, 30, 30}, SkPath::kCW_Direction); |
| path.addRect({20, 20, 40, 40}, SkPath::kCW_Direction); |
| path.addRect({10, 60, 30, 80}, SkPath::kCW_Direction); |
| path.addRect({20, 70, 40, 90}, SkPath::kCCW_Direction); |
| SkPaint strokePaint; |
| strokePaint.setStyle(SkPaint::kStroke_Style); |
| SkRect clipRect = {0, 0, 51, 100}; |
| canvas->drawPath(path, strokePaint); |
| SkPaint fillPaint; |
| for (auto fillType : { SkPath::kWinding_FillType, SkPath::kEvenOdd_FillType, |
| SkPath::kInverseWinding_FillType, SkPath::kInverseEvenOdd_FillType } ) { |
| canvas->translate(51, 0); |
| canvas->save(); |
| canvas->clipRect(clipRect); |
| path.setFillType(fillType); |
| canvas->drawPath(path, fillPaint); |
| canvas->restore(); |
| } |
| } |
| ## |
| |
| #Const kWinding_FillType 0 |
| #Line # is enclosed by a non-zero sum of Contour Directions ## |
| ## |
| #Const kEvenOdd_FillType 1 |
| #Line # is enclosed by an odd number of Contours ## |
| ## |
| #Const kInverseWinding_FillType 2 |
| #Line # is enclosed by a zero sum of Contour Directions ## |
| ## |
| #Const kInverseEvenOdd_FillType 3 |
| #Line # is enclosed by an even number of Contours ## |
| ## |
| |
| #Example |
| #Height 230 |
| void draw(SkCanvas* canvas) { |
| SkPath path; |
| path.addRect({20, 10, 80, 70}, SkPath::kCW_Direction); |
| path.addRect({40, 30, 100, 90}, SkPath::kCW_Direction); |
| SkPaint strokePaint; |
| strokePaint.setStyle(SkPaint::kStroke_Style); |
| SkRect clipRect = {0, 0, 128, 128}; |
| canvas->drawPath(path, strokePaint); |
| canvas->drawLine({0, 50}, {120, 50}, strokePaint); |
| SkPaint textPaint; |
| textPaint.setAntiAlias(true); |
| textPaint.setTextAlign(SkPaint::kCenter_Align); |
| SkScalar textHPos[] = { 10, 30, 60, 90, 110 }; |
| canvas->drawPosTextH("01210", 5, textHPos, 48, textPaint); |
| textPaint.setTextSize(18); |
| canvas->translate(0, 128); |
| canvas->scale(.5f, .5f); |
| canvas->drawString("inverse", 384, 150, textPaint); |
| SkPaint fillPaint; |
| for (auto fillType : { SkPath::kWinding_FillType, SkPath::kEvenOdd_FillType, |
| SkPath::kInverseWinding_FillType, SkPath::kInverseEvenOdd_FillType } ) { |
| canvas->save(); |
| canvas->clipRect(clipRect); |
| path.setFillType(fillType); |
| canvas->drawPath(path, fillPaint); |
| canvas->restore(); |
| canvas->drawString(fillType & 1 ? "even-odd" : "winding", 64, 170, textPaint); |
| canvas->translate(128, 0); |
| } |
| } |
| ## |
| |
| #SeeAlso SkPaint::Style Direction getFillType setFillType |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method FillType getFillType() const |
| |
| #In Fill_Type |
| #Line # returns Fill_Type: winding, even-odd, inverse ## |
| Returns FillType, the rule used to fill Path. FillType of a new Path is |
| kWinding_FillType. |
| |
| #Return one of: kWinding_FillType, kEvenOdd_FillType, kInverseWinding_FillType, |
| kInverseEvenOdd_FillType |
| ## |
| |
| #Example |
| SkPath path; |
| SkDebugf("default path fill type is %s\n", |
| path.getFillType() == SkPath::kWinding_FillType ? "kWinding_FillType" : |
| path.getFillType() == SkPath::kEvenOdd_FillType ? "kEvenOdd_FillType" : |
| path.getFillType() == SkPath::kInverseWinding_FillType ? "kInverseWinding_FillType" : |
| "kInverseEvenOdd_FillType"); |
| #StdOut |
| default path fill type is kWinding_FillType |
| ## |
| ## |
| |
| #SeeAlso FillType setFillType isInverseFillType |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void setFillType(FillType ft) |
| |
| #In Fill_Type |
| #Line # sets Fill_Type: winding, even-odd, inverse ## |
| Sets FillType, the rule used to fill Path. While there is no check |
| that ft is legal, values outside of FillType are not supported. |
| |
| #Param ft one of: kWinding_FillType, kEvenOdd_FillType, kInverseWinding_FillType, |
| kInverseEvenOdd_FillType |
| ## |
| |
| #Example |
| #Description |
| If empty Path is set to inverse FillType, it fills all pixels. |
| ## |
| #Height 64 |
| SkPath path; |
| path.setFillType(SkPath::kInverseWinding_FillType); |
| SkPaint paint; |
| paint.setColor(SK_ColorBLUE); |
| canvas->drawPath(path, paint); |
| ## |
| |
| #SeeAlso FillType getFillType toggleInverseFillType |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isInverseFillType() const |
| |
| #In Fill_Type |
| #Line # returns if Fill_Type fills outside geometry ## |
| Returns if FillType describes area outside Path geometry. The inverse fill area |
| extends indefinitely. |
| |
| #Return true if FillType is kInverseWinding_FillType or kInverseEvenOdd_FillType ## |
| |
| #Example |
| SkPath path; |
| SkDebugf("default path fill type is inverse: %s\n", |
| path.isInverseFillType() ? "true" : "false"); |
| #StdOut |
| default path fill type is inverse: false |
| ## |
| ## |
| |
| #SeeAlso FillType getFillType setFillType toggleInverseFillType |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void toggleInverseFillType() |
| |
| #In Fill_Type |
| #Line # toggles Fill_Type between inside and outside geometry ## |
| Replace FillType with its inverse. The inverse of FillType describes the area |
| unmodified by the original FillType. |
| |
| #Table |
| #Legend |
| # FillType # toggled FillType ## |
| ## |
| # kWinding_FillType # kInverseWinding_FillType ## |
| # kEvenOdd_FillType # kInverseEvenOdd_FillType ## |
| # kInverseWinding_FillType # kWinding_FillType ## |
| # kInverseEvenOdd_FillType # kEvenOdd_FillType ## |
| ## |
| |
| #Example |
| #Description |
| Path drawn normally and through its inverse touches every pixel once. |
| ## |
| #Height 100 |
| SkPath path; |
| SkPaint paint; |
| paint.setColor(SK_ColorRED); |
| paint.setTextSize(80); |
| paint.getTextPath("ABC", 3, 20, 80, &path); |
| canvas->drawPath(path, paint); |
| path.toggleInverseFillType(); |
| paint.setColor(SK_ColorGREEN); |
| canvas->drawPath(path, paint); |
| ## |
| |
| #SeeAlso FillType getFillType setFillType isInverseFillType |
| |
| ## |
| |
| #Subtopic Fill_Type ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Subtopic Convexity |
| #Line # if Path is concave or convex ## |
| |
| #Enum Convexity |
| #Line # returns if Path is convex or concave ## |
| |
| #Code |
| enum Convexity : uint8_t { |
| kUnknown_Convexity, |
| kConvex_Convexity, |
| kConcave_Convexity, |
| }; |
| ## |
| |
| Path is convex if it contains one Contour and Contour loops no more than |
| 360 degrees, and Contour angles all have same Direction. Convex Path |
| may have better performance and require fewer resources on GPU_Surface. |
| |
| Path is concave when either at least one Direction change is clockwise and |
| another is counterclockwise, or the sum of the changes in Direction is not 360 |
| degrees. |
| |
| Initially Path Convexity is kUnknown_Convexity. Path Convexity is computed |
| if needed by destination Surface. |
| |
| #Const kUnknown_Convexity 0 |
| #Line # indicates Convexity has not been determined ## |
| ## |
| #Const kConvex_Convexity 1 |
| #Line # one Contour made of a simple geometry without indentations ## |
| ## |
| #Const kConcave_Convexity 2 |
| #Line # more than one Contour, or a geometry with indentations ## |
| ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| SkPoint quad[] = {{70, 70}, {20, 20}, {120, 20}, {120, 120}}; |
| const char* labels[] = { "unknown", "convex", "concave" }; |
| for (SkScalar x : { 40, 100 } ) { |
| SkPath path; |
| quad[0].fX = x; |
| path.addPoly(quad, SK_ARRAY_COUNT(quad), true); |
| canvas->drawPath(path, paint); |
| canvas->drawString(labels[(int) path.getConvexity()], 30, 100, paint); |
| canvas->translate(100, 100); |
| } |
| } |
| ## |
| |
| #SeeAlso Contour Direction getConvexity getConvexityOrUnknown setConvexity isConvex |
| |
| #Enum Convexity ## |
| |
| #Method Convexity getConvexity() const |
| |
| #In Convexity |
| #Line # returns geometry convexity, computing if necessary ## |
| Computes Convexity if required, and returns stored value. |
| Convexity is computed if stored value is kUnknown_Convexity, |
| or if Path has been altered since Convexity was computed or set. |
| |
| #Return computed or stored Convexity ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& path) -> void { |
| SkDebugf("%s path convexity is %s\n", prefix, |
| SkPath::kUnknown_Convexity == path.getConvexity() ? "unknown" : |
| SkPath::kConvex_Convexity == path.getConvexity() ? "convex" : "concave"); }; |
| SkPath path; |
| debugster("initial", path); |
| path.lineTo(50, 0); |
| debugster("first line", path); |
| path.lineTo(50, 50); |
| debugster("second line", path); |
| path.lineTo(100, 50); |
| debugster("third line", path); |
| } |
| ## |
| |
| #SeeAlso Convexity Contour Direction getConvexityOrUnknown setConvexity isConvex |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method Convexity getConvexityOrUnknown() const |
| |
| #In Convexity |
| #Line # returns geometry convexity if known ## |
| Returns last computed Convexity, or kUnknown_Convexity if |
| Path has been altered since Convexity was computed or set. |
| |
| #Return stored Convexity ## |
| |
| #Example |
| #Description |
| Convexity is unknown unless getConvexity is called without a subsequent call |
| that alters the path. |
| ## |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& path) -> void { |
| SkDebugf("%s path convexity is %s\n", prefix, |
| SkPath::kUnknown_Convexity == path.getConvexityOrUnknown() ? "unknown" : |
| SkPath::kConvex_Convexity == path.getConvexityOrUnknown() ? "convex" : "concave"); }; |
| SkPath path; |
| debugster("initial", path); |
| path.lineTo(50, 0); |
| debugster("first line", path); |
| path.getConvexity(); |
| path.lineTo(50, 50); |
| debugster("second line", path); |
| path.lineTo(100, 50); |
| path.getConvexity(); |
| debugster("third line", path); |
| } |
| ## |
| |
| #SeeAlso Convexity Contour Direction getConvexity setConvexity isConvex |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void setConvexity(Convexity convexity) |
| |
| #In Convexity |
| #Line # sets if geometry is convex to avoid future computation ## |
| Stores convexity so that it is later returned by getConvexity or getConvexityOrUnknown. |
| convexity may differ from getConvexity, although setting an incorrect value may |
| cause incorrect or inefficient drawing. |
| |
| If convexity is kUnknown_Convexity: getConvexity will |
| compute Convexity, and getConvexityOrUnknown will return kUnknown_Convexity. |
| |
| If convexity is kConvex_Convexity or kConcave_Convexity, getConvexity |
| and getConvexityOrUnknown will return convexity until the path is |
| altered. |
| |
| #Param convexity one of: kUnknown_Convexity, kConvex_Convexity, or kConcave_Convexity ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& path) -> void { |
| SkDebugf("%s path convexity is %s\n", prefix, |
| SkPath::kUnknown_Convexity == path.getConvexity() ? "unknown" : |
| SkPath::kConvex_Convexity == path.getConvexity() ? "convex" : "concave"); }; |
| SkPoint quad[] = {{70, 70}, {20, 20}, {120, 20}, {120, 120}}; |
| SkPath path; |
| path.addPoly(quad, SK_ARRAY_COUNT(quad), true); |
| debugster("initial", path); |
| path.setConvexity(SkPath::kConcave_Convexity); |
| debugster("after forcing concave", path); |
| path.setConvexity(SkPath::kUnknown_Convexity); |
| debugster("after forcing unknown", path); |
| } |
| ## |
| |
| #SeeAlso Convexity Contour Direction getConvexity getConvexityOrUnknown isConvex |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isConvex() const |
| |
| #In Convexity |
| #Line # returns if geometry is convex ## |
| Computes Convexity if required, and returns true if value is kConvex_Convexity. |
| If setConvexity was called with kConvex_Convexity or kConcave_Convexity, and |
| the path has not been altered, Convexity is not recomputed. |
| |
| #Return true if Convexity stored or computed is kConvex_Convexity ## |
| |
| #Example |
| #Description |
| Concave shape is erroneously considered convex after a forced call to |
| setConvexity. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| SkPoint quad[] = {{70, 70}, {20, 20}, {120, 20}, {120, 120}}; |
| for (SkScalar x : { 40, 100 } ) { |
| SkPath path; |
| quad[0].fX = x; |
| path.addPoly(quad, SK_ARRAY_COUNT(quad), true); |
| path.setConvexity(SkPath::kConvex_Convexity); |
| canvas->drawPath(path, paint); |
| canvas->drawString(path.isConvex() ? "convex" : "not convex", 30, 100, paint); |
| canvas->translate(100, 100); |
| } |
| } |
| ## |
| |
| #SeeAlso Convexity Contour Direction getConvexity getConvexityOrUnknown setConvexity |
| |
| ## |
| |
| #Subtopic Convexity ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isOval(SkRect* bounds) const |
| #In Property |
| #Line # returns if describes Oval ## |
| |
| Returns true if this path is recognized as an oval or circle. |
| |
| bounds receives bounds of Oval. |
| |
| bounds is unmodified if Oval is not found. |
| |
| #Param bounds storage for bounding Rect of Oval; may be nullptr ## |
| |
| #Return true if Path is recognized as an oval or circle ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| SkPath path; |
| path.addOval({20, 20, 220, 220}); |
| SkRect bounds; |
| if (path.isOval(&bounds)) { |
| paint.setColor(0xFF9FBFFF); |
| canvas->drawRect(bounds, paint); |
| } |
| paint.setColor(0x3f000000); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso Oval addCircle addOval |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isRRect(SkRRect* rrect) const |
| #In Property |
| #Line # returns if describes Round_Rect ## |
| |
| Returns true if this path is recognized as a SkRRect (but not an oval/circle or rect). |
| |
| rrect receives bounds of Round_Rect. |
| |
| rrect is unmodified if Round_Rect is not found. |
| |
| #Param rrect storage for bounding Rect of Round_Rect; may be nullptr ## |
| |
| #Return true if Path contains only Round_Rect ## |
| |
| #Example |
| #Description |
| Draw rounded rectangle and its bounds. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| SkPath path; |
| path.addRRect(SkRRect::MakeRectXY({20, 20, 220, 220}, 30, 50)); |
| SkRRect rrect; |
| if (path.isRRect(&rrect)) { |
| const SkRect& bounds = rrect.rect(); |
| paint.setColor(0xFF9FBFFF); |
| canvas->drawRect(bounds, paint); |
| } |
| paint.setColor(0x3f000000); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso Round_Rect addRoundRect addRRect |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void reset() |
| #In Constructor |
| #Line # removes Verb_Array, Point_Array, and Weights; frees memory ## |
| Sets Path to its initial state. |
| Removes Verb_Array, Point_Array, and Weights, and sets FillType to kWinding_FillType. |
| Internal storage associated with Path is released. |
| |
| #Example |
| SkPath path1, path2; |
| path1.setFillType(SkPath::kInverseWinding_FillType); |
| path1.addRect({10, 20, 30, 40}); |
| SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!'); |
| path1.reset(); |
| SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!'); |
| ## |
| |
| #SeeAlso rewind() |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void rewind() |
| #In Constructor |
| #Line # removes Verb_Array, Point_Array, and Weights, keeping memory ## |
| Sets Path to its initial state, preserving internal storage. |
| Removes Verb_Array, Point_Array, and Weights, and sets FillType to kWinding_FillType. |
| Internal storage associated with Path is retained. |
| |
| Use rewind() instead of reset() if Path storage will be reused and performance |
| is critical. |
| |
| #Example |
| #Description |
| Although path1 retains its internal storage, it is indistinguishable from |
| a newly initialized path. |
| ## |
| SkPath path1, path2; |
| path1.setFillType(SkPath::kInverseWinding_FillType); |
| path1.addRect({10, 20, 30, 40}); |
| SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!'); |
| path1.rewind(); |
| SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!'); |
| ## |
| |
| #SeeAlso reset() |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isEmpty() const |
| #In Property |
| #Line # returns if verb count is zero ## |
| Empty Path may have FillType but has no SkPoint, Verb, or Conic_Weight. |
| SkPath() constructs empty Path; reset() and (rewind) make Path empty. |
| |
| #Return true if the path contains no Verb array ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& path) -> void { |
| SkDebugf("%s path is %s" "empty\n", prefix, path.isEmpty() ? "" : "not "); |
| }; |
| SkPath path; |
| debugster("initial", path); |
| path.moveTo(0, 0); |
| debugster("after moveTo", path); |
| path.rewind(); |
| debugster("after rewind", path); |
| path.lineTo(0, 0); |
| debugster("after lineTo", path); |
| path.reset(); |
| debugster("after reset", path); |
| } |
| #StdOut |
| initial path is empty |
| after moveTo path is not empty |
| after rewind path is empty |
| after lineTo path is not empty |
| after reset path is empty |
| ## |
| ## |
| |
| #SeeAlso SkPath() reset() rewind() |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isLastContourClosed() const |
| #In Property |
| #Line # returns if final Contour forms a loop ## |
| Contour is closed if Path Verb array was last modified by close(). When stroked, |
| closed Contour draws Paint_Stroke_Join instead of Paint_Stroke_Cap at first and last Point. |
| |
| #Return true if the last Contour ends with a kClose_Verb ## |
| |
| #Example |
| #Description |
| close() has no effect if Path is empty; isLastContourClosed() returns |
| false until Path has geometry followed by close(). |
| ## |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& path) -> void { |
| SkDebugf("%s last contour is %s" "closed\n", prefix, |
| path.isLastContourClosed() ? "" : "not "); |
| }; |
| SkPath path; |
| debugster("initial", path); |
| path.close(); |
| debugster("after close", path); |
| path.lineTo(0, 0); |
| debugster("after lineTo", path); |
| path.close(); |
| debugster("after close", path); |
| } |
| #StdOut |
| initial last contour is not closed |
| after close last contour is not closed |
| after lineTo last contour is not closed |
| after close last contour is closed |
| ## |
| ## |
| |
| #SeeAlso close() |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isFinite() const |
| #In Property |
| #Line # returns if all Point values are finite ## |
| Returns true for finite Point array values between negative SK_ScalarMax and |
| positive SK_ScalarMax. Returns false for any Point array value of |
| SK_ScalarInfinity, SK_ScalarNegativeInfinity, or SK_ScalarNaN. |
| |
| #Return true if all Point values are finite ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& path) -> void { |
| SkDebugf("%s path is %s" "finite\n", prefix, path.isFinite() ? "" : "not "); |
| }; |
| SkPath path; |
| debugster("initial", path); |
| path.lineTo(SK_ScalarMax, SK_ScalarMax); |
| debugster("after line", path); |
| SkMatrix matrix; |
| matrix.setScale(2, 2); |
| path.transform(matrix); |
| debugster("after scale", path); |
| } |
| #StdOut |
| initial path is finite |
| after line path is finite |
| after scale path is not finite |
| ## |
| ## |
| |
| #SeeAlso SkScalar |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isVolatile() const |
| #In Property |
| #In Volatile |
| #Line # returns if Device should not cache ## |
| Returns true if the path is volatile; it will not be altered or discarded |
| by the caller after it is drawn. Paths by default have volatile set false, allowing |
| Surface to attach a cache of data which speeds repeated drawing. If true, Surface |
| may not speed repeated drawing. |
| |
| #Return true if caller will alter Path after drawing ## |
| |
| #Example |
| SkPath path; |
| SkDebugf("volatile by default is %s\n", path.isVolatile() ? "true" : "false"); |
| #StdOut |
| volatile by default is false |
| ## |
| ## |
| |
| #SeeAlso setIsVolatile |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Volatile |
| #Populate |
| #Line # caching attribute ## |
| ## |
| |
| #Method void setIsVolatile(bool isVolatile) |
| #In Volatile |
| #Line # sets if Device should not cache ## |
| Specify whether Path is volatile; whether it will be altered or discarded |
| by the caller after it is drawn. Paths by default have volatile set false, allowing |
| Device to attach a cache of data which speeds repeated drawing. |
| |
| Mark temporary paths, discarded or modified after use, as volatile |
| to inform Device that the path need not be cached. |
| |
| Mark animating Path volatile to improve performance. |
| Mark unchanging Path non-volatile to improve repeated rendering. |
| |
| Raster_Surface Path draws are affected by volatile for some shadows. |
| GPU_Surface Path draws are affected by volatile for some shadows and concave geometries. |
| |
| #Param isVolatile true if caller will alter Path after drawing ## |
| |
| #Example |
| #Height 50 |
| #Width 50 |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPath path; |
| path.setIsVolatile(true); |
| path.lineTo(40, 40); |
| canvas->drawPath(path, paint); |
| path.rewind(); |
| path.moveTo(0, 40); |
| path.lineTo(40, 0); |
| canvas->drawPath(path, paint); |
| ## |
| |
| #ToDo tie example to bench to show how volatile affects speed or dm to show resource usage ## |
| |
| #SeeAlso isVolatile |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static bool IsLineDegenerate(const SkPoint& p1, const SkPoint& p2, bool exact) |
| #In Property |
| #Line # returns if Line is very small ## |
| Test if Line between Point pair is degenerate. |
| Line with no length or that moves a very short distance is degenerate; it is |
| treated as a point. |
| |
| exact changes the equality test. If true, returns true only if p1 equals p2. |
| If false, returns true if p1 equals or nearly equals p2. |
| |
| #Param p1 line start point ## |
| #Param p2 line end point ## |
| #Param exact if false, allow nearly equals ## |
| |
| #Return true if Line is degenerate; its length is effectively zero ## |
| |
| #Example |
| #Description |
| As single precision floats, 100 and 100.000001 have the same bit representation, |
| and are exactly equal. 100 and 100.0001 have different bit representations, and |
| are not exactly equal, but are nearly equal. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPoint points[] = { {100, 100}, {100.000001f, 100.000001f}, {100.0001f, 100.0001f} }; |
| for (size_t i = 0; i < SK_ARRAY_COUNT(points) - 1; ++i) { |
| for (bool exact : { false, true } ) { |
| SkDebugf("line from (%1.8g,%1.8g) to (%1.8g,%1.8g) is %s" "degenerate, %s\n", |
| points[i].fX, points[i].fY, points[i + 1].fX, points[i + 1].fY, |
| SkPath::IsLineDegenerate(points[i], points[i + 1], exact) |
| ? "" : "not ", exact ? "exactly" : "nearly"); |
| } |
| } |
| } |
| #StdOut |
| line from (100,100) to (100,100) is degenerate, nearly |
| line from (100,100) to (100,100) is degenerate, exactly |
| line from (100,100) to (100.0001,100.0001) is degenerate, nearly |
| line from (100,100) to (100.0001,100.0001) is not degenerate, exactly |
| #StdOut ## |
| ## |
| |
| #SeeAlso IsQuadDegenerate IsCubicDegenerate |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static bool IsQuadDegenerate(const SkPoint& p1, const SkPoint& p2, |
| const SkPoint& p3, bool exact) |
| #In Property |
| #Line # returns if Quad is very small ## |
| |
| Test if Quad is degenerate. |
| Quad with no length or that moves a very short distance is degenerate; it is |
| treated as a point. |
| |
| #Param p1 Quad start point ## |
| #Param p2 Quad control point ## |
| #Param p3 Quad end point ## |
| #Param exact if true, returns true only if p1, p2, and p3 are equal; |
| if false, returns true if p1, p2, and p3 are equal or nearly equal |
| ## |
| |
| #Return true if Quad is degenerate; its length is effectively zero ## |
| |
| #Example |
| #Description |
| As single precision floats: 100, 100.00001, and 100.00002 have different bit representations |
| but nearly the same value. Translating all three by 1000 gives them the same bit representation; |
| the fractional portion of the number can not be represented by the float and is lost. |
| ## |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const SkPath& path, bool exact) -> void { |
| SkDebugf("quad (%1.8g,%1.8g), (%1.8g,%1.8g), (%1.8g,%1.8g) is %s" "degenerate, %s\n", |
| path.getPoint(0).fX, path.getPoint(0).fY, path.getPoint(1).fX, |
| path.getPoint(1).fY, path.getPoint(2).fX, path.getPoint(2).fY, |
| SkPath::IsQuadDegenerate(path.getPoint(0), path.getPoint(1), path.getPoint(2), exact) ? |
| "" : "not ", exact ? "exactly" : "nearly"); |
| }; |
| SkPath path, offset; |
| path.moveTo({100, 100}); |
| path.quadTo({100.00001f, 100.00001f}, {100.00002f, 100.00002f}); |
| offset.addPath(path, 1000, 1000); |
| for (bool exact : { false, true } ) { |
| debugster(path, exact); |
| debugster(offset, exact); |
| } |
| } |
| #StdOut |
| quad (100,100), (100.00001,100.00001), (100.00002,100.00002) is degenerate, nearly |
| quad (1100,1100), (1100,1100), (1100,1100) is degenerate, nearly |
| quad (100,100), (100.00001,100.00001), (100.00002,100.00002) is not degenerate, exactly |
| quad (1100,1100), (1100,1100), (1100,1100) is degenerate, exactly |
| #StdOut ## |
| ## |
| |
| #SeeAlso IsLineDegenerate IsCubicDegenerate |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static bool IsCubicDegenerate(const SkPoint& p1, const SkPoint& p2, |
| const SkPoint& p3, const SkPoint& p4, bool exact) |
| #In Property |
| #Line # returns if Cubic is very small ## |
| |
| Test if Cubic is degenerate. |
| Cubic with no length or that moves a very short distance is degenerate; it is |
| treated as a point. |
| |
| #Param p1 Cubic start point ## |
| #Param p2 Cubic control point 1 ## |
| #Param p3 Cubic control point 2 ## |
| #Param p4 Cubic end point ## |
| #Param exact if true, returns true only if p1, p2, p3, and p4 are equal; |
| if false, returns true if p1, p2, p3, and p4 are equal or nearly equal |
| ## |
| |
| #Return true if Cubic is degenerate; its length is effectively zero ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPoint points[] = {{1, 0}, {0, 0}, {0, 0}, {0, 0}}; |
| SkScalar step = 1; |
| SkScalar prior, length, degenerate; |
| do { |
| prior = points[0].fX; |
| step /= 2; |
| if (SkPath::IsCubicDegenerate(points[0], points[1], points[2], points[3], false)) { |
| degenerate = prior; |
| points[0].fX += step; |
| } else { |
| length = prior; |
| points[0].fX -= step; |
| } |
| } while (prior != points[0].fX); |
| SkDebugf("%1.8g is degenerate\n", degenerate); |
| SkDebugf("%1.8g is length\n", length); |
| } |
| #StdOut |
| 0.00024414062 is degenerate |
| 0.00024414065 is length |
| #StdOut ## |
| ## |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isLine(SkPoint line[2]) const |
| #In Property |
| #Line # returns if describes Line ## |
| Returns true if Path contains only one Line; |
| Path_Verb array has two entries: kMove_Verb, kLine_Verb. |
| If Path contains one Line and line is not nullptr, line is set to |
| Line start point and Line end point. |
| Returns false if Path is not one Line; line is unaltered. |
| |
| #Param line storage for Line. May be nullptr ## |
| |
| #Return true if Path contains exactly one Line ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& path) -> void { |
| SkPoint line[2]; |
| if (path.isLine(line)) { |
| SkDebugf("%s is line (%1.8g,%1.8g) (%1.8g,%1.8g)\n", prefix, |
| line[0].fX, line[0].fY, line[1].fX, line[1].fY); |
| } else { |
| SkDebugf("%s is not line\n", prefix); |
| } |
| }; |
| SkPath path; |
| debugster("empty", path); |
| path.lineTo(0, 0); |
| debugster("zero line", path); |
| path.rewind(); |
| path.moveTo(10, 10); |
| path.lineTo(20, 20); |
| debugster("line", path); |
| path.moveTo(20, 20); |
| debugster("second move", path); |
| } |
| #StdOut |
| empty is not line |
| zero line is line (0,0) (0,0) |
| line is line (10,10) (20,20) |
| second move is not line |
| ## |
| ## |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Subtopic Point_Array |
| #Line # end points and control points for lines and curves ## |
| #Substitute SkPoint array |
| |
| Point_Array contains Points satisfying the allocated Points for |
| each Verb in Verb_Array. For instance, Path containing one Contour with Line |
| and Quad is described by Verb_Array: Verb::kMoveTo, Verb::kLineTo, Verb::kQuadTo; and |
| one Point for move, one Point for Line, two Points for Quad; totaling four Points. |
| |
| Point_Array may be read directly from Path with getPoints, or inspected with |
| getPoint, with Iter, or with RawIter. |
| |
| #Method int getPoints(SkPoint points[], int max) const |
| |
| #In Point_Array |
| #Line # returns Point_Array ## |
| Returns number of points in Path. Up to max points are copied. |
| points may be nullptr; then, max must be zero. |
| If max is greater than number of points, excess points storage is unaltered. |
| |
| #Param points storage for Path Point array. May be nullptr ## |
| #Param max maximum to copy; must be greater than or equal to zero ## |
| |
| #Return Path Point array length ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& path, SkPoint* points, int max) -> void { |
| int count = path.getPoints(points, max); |
| SkDebugf("%s point count: %d ", prefix, count); |
| for (int i = 0; i < SkTMin(count, max) && points; ++i) { |
| SkDebugf("(%1.8g,%1.8g) ", points[i].fX, points[i].fY); |
| } |
| SkDebugf("\n"); |
| }; |
| SkPath path; |
| path.lineTo(20, 20); |
| path.lineTo(-10, -10); |
| SkPoint points[3]; |
| debugster("no points", path, nullptr, 0); |
| debugster("zero max", path, points, 0); |
| debugster("too small", path, points, 2); |
| debugster("just right", path, points, path.countPoints()); |
| } |
| #StdOut |
| no points point count: 3 |
| zero max point count: 3 |
| too small point count: 3 (0,0) (20,20) |
| just right point count: 3 (0,0) (20,20) (-10,-10) |
| ## |
| ## |
| |
| #SeeAlso countPoints getPoint |
| ## |
| |
| #Method int countPoints() const |
| |
| #In Point_Array |
| #Line # returns Point_Array length ## |
| Returns the number of points in Path. |
| Point count is initially zero. |
| |
| #Return Path Point array length ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& path) -> void { |
| SkDebugf("%s point count: %d\n", prefix, path.countPoints()); |
| }; |
| SkPath path; |
| debugster("empty", path); |
| path.lineTo(0, 0); |
| debugster("zero line", path); |
| path.rewind(); |
| path.moveTo(10, 10); |
| path.lineTo(20, 20); |
| debugster("line", path); |
| path.moveTo(20, 20); |
| debugster("second move", path); |
| } |
| #StdOut |
| empty point count: 0 |
| zero line point count: 2 |
| line point count: 2 |
| second move point count: 3 |
| ## |
| ## |
| |
| #SeeAlso getPoints |
| ## |
| |
| #Method SkPoint getPoint(int index) const |
| |
| #In Point_Array |
| #Line # returns entry from Point_Array ## |
| Returns Point at index in Point_Array. Valid range for index is |
| 0 to countPoints - 1. |
| Returns (0, 0) if index is out of range. |
| |
| #Param index Point array element selector ## |
| |
| #Return Point array value or (0, 0) ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPath path; |
| path.lineTo(20, 20); |
| path.offset(-10, -10); |
| for (int i= 0; i < path.countPoints(); ++i) { |
| SkDebugf("point %d: (%1.8g,%1.8g)\n", i, path.getPoint(i).fX, path.getPoint(i).fY); |
| } |
| } |
| #StdOut |
| point 0: (-10,-10) |
| point 1: (10,10) |
| ## |
| ## |
| |
| #SeeAlso countPoints getPoints |
| ## |
| |
| |
| #Subtopic Point_Array ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Verb_Array |
| #Line # line and curve type for points ## |
| |
| Verb_Array always starts with kMove_Verb. |
| If kClose_Verb is not the last entry, it is always followed by kMove_Verb; |
| the quantity of kMove_Verb equals the Contour count. |
| Verb_Array does not include or count kDone_Verb; it is a convenience |
| returned when iterating through Verb_Array. |
| |
| Verb_Array may be read directly from Path with getVerbs, or inspected with Iter, |
| or with RawIter. |
| |
| #Method int countVerbs() const |
| |
| #In Verb_Array |
| #Line # returns Verb_Array length ## |
| Returns the number of Verbs: kMove_Verb, kLine_Verb, kQuad_Verb, kConic_Verb, |
| kCubic_Verb, and kClose_Verb; added to Path. |
| |
| #Return length of Verb_Array ## |
| |
| #Example |
| SkPath path; |
| SkDebugf("empty verb count: %d\n", path.countVerbs()); |
| path.addRoundRect({10, 20, 30, 40}, 5, 5); |
| SkDebugf("round rect verb count: %d\n", path.countVerbs()); |
| #StdOut |
| empty verb count: 0 |
| round rect verb count: 10 |
| ## |
| ## |
| |
| #SeeAlso getVerbs Iter RawIter |
| |
| ## |
| |
| #Method int getVerbs(uint8_t verbs[], int max) const |
| |
| #In Verb_Array |
| #Line # returns Verb_Array ## |
| Returns the number of verbs in the path. Up to max verbs are copied. The |
| verbs are copied as one byte per verb. |
| |
| #Param verbs storage for verbs, may be nullptr ## |
| #Param max maximum number to copy into verbs ## |
| |
| #Return the actual number of verbs in the path ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& path, uint8_t* verbs, int max) -> void { |
| int count = path.getVerbs(verbs, max); |
| SkDebugf("%s verb count: %d ", prefix, count); |
| const char* verbStr[] = { "move", "line", "quad", "conic", "cubic", "close" }; |
| for (int i = 0; i < SkTMin(count, max) && verbs; ++i) { |
| SkDebugf("%s ", verbStr[verbs[i]]); |
| } |
| SkDebugf("\n"); |
| }; |
| SkPath path; |
| path.lineTo(20, 20); |
| path.lineTo(-10, -10); |
| uint8_t verbs[3]; |
| debugster("no verbs", path, nullptr, 0); |
| debugster("zero max", path, verbs, 0); |
| debugster("too small", path, verbs, 2); |
| debugster("just right", path, verbs, path.countVerbs()); |
| } |
| #StdOut |
| no verbs verb count: 3 |
| zero max verb count: 3 |
| too small verb count: 3 move line |
| just right verb count: 3 move line line |
| ## |
| ## |
| |
| #SeeAlso countVerbs getPoints Iter RawIter |
| ## |
| |
| #Subtopic Verb_Array ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void swap(SkPath& other) |
| #In Operator |
| #Line # exchanges Path pair ## |
| Exchanges the Verb_Array, Point_Array, Weights, and Fill_Type with other. |
| Cached state is also exchanged. swap() internally exchanges pointers, so |
| it is lightweight and does not allocate memory. |
| |
| swap() usage has largely been replaced by operator=(const SkPath& path). |
| Paths do not copy their content on assignment until they are written to, |
| making assignment as efficient as swap(). |
| |
| #Param other Path exchanged by value ## |
| |
| #Example |
| SkPath path1, path2; |
| path1.addRect({10, 20, 30, 40}); |
| path1.swap(path2); |
| const SkRect& b1 = path1.getBounds(); |
| SkDebugf("path1 bounds = %g, %g, %g, %g\n", b1.fLeft, b1.fTop, b1.fRight, b1.fBottom); |
| const SkRect& b2 = path2.getBounds(); |
| SkDebugf("path2 bounds = %g, %g, %g, %g\n", b2.fLeft, b2.fTop, b2.fRight, b2.fBottom); |
| #StdOut |
| path1 bounds = 0, 0, 0, 0 |
| path2 bounds = 10, 20, 30, 40 |
| #StdOut ## |
| ## |
| |
| #SeeAlso operator=(const SkPath& path) |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method const SkRect& getBounds() const |
| #In Property |
| #Line # returns maximum and minimum of Point_Array ## |
| Returns minimum and maximum axes values of Point_Array. |
| Returns (0, 0, 0, 0) if Path contains no points. Returned bounds width and height may |
| be larger or smaller than area affected when Path is drawn. |
| |
| Rect returned includes all Points added to Path, including Points associated with |
| kMove_Verb that define empty Contours. |
| |
| #Return bounds of all Points in Point_Array ## |
| |
| #Example |
| #Description |
| Bounds of upright Circle can be predicted from center and radius. |
| Bounds of rotated Circle includes control Points outside of filled area. |
| ## |
| auto debugster = [](const char* prefix, const SkPath& path) -> void { |
| const SkRect& bounds = path.getBounds(); |
| SkDebugf("%s bounds = %g, %g, %g, %g\n", prefix, |
| bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom); |
| }; |
| SkPath path; |
| debugster("empty", path); |
| path.addCircle(50, 45, 25); |
| debugster("circle", path); |
| SkMatrix matrix; |
| matrix.setRotate(45, 50, 45); |
| path.transform(matrix); |
| debugster("rotated circle", path); |
| #StdOut |
| empty bounds = 0, 0, 0, 0 |
| circle bounds = 25, 20, 75, 70 |
| rotated circle bounds = 14.6447, 9.64466, 85.3553, 80.3553 |
| ## |
| ## |
| |
| #SeeAlso computeTightBounds updateBoundsCache |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Utility |
| #Populate |
| #Line # rarely called management functions ## |
| ## |
| |
| #Method void updateBoundsCache() const |
| #In Utility |
| #Line # refreshes result of getBounds ## |
| Update internal bounds so that subsequent calls to getBounds are instantaneous. |
| Unaltered copies of Path may also access cached bounds through getBounds. |
| |
| For now, identical to calling getBounds and ignoring the returned value. |
| |
| Call to prepare Path subsequently drawn from multiple threads, |
| to avoid a race condition where each draw separately computes the bounds. |
| |
| #Example |
| double times[2] = { 0, 0 }; |
| for (int i = 0; i < 10000; ++i) { |
| SkPath path; |
| for (int j = 1; j < 100; ++ j) { |
| path.addCircle(50 + j, 45 + j, 25 + j); |
| } |
| if (1 & i) { |
| path.updateBoundsCache(); |
| } |
| double start = SkTime::GetNSecs(); |
| (void) path.getBounds(); |
| times[1 & i] += SkTime::GetNSecs() - start; |
| } |
| SkDebugf("uncached avg: %g ms\n", times[0] * 1e-6); |
| SkDebugf("cached avg: %g ms\n", times[1] * 1e-6); |
| #StdOut |
| #Volatile |
| uncached avg: 0.18048 ms |
| cached avg: 0.182784 ms |
| ## |
| ## |
| |
| #SeeAlso getBounds |
| #ToDo the results don't make sense, need to profile to figure this out ## |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method SkRect computeTightBounds() const |
| #In Property |
| #Line # returns extent of geometry ## |
| Returns minimum and maximum axes values of the lines and curves in Path. |
| Returns (0, 0, 0, 0) if Path contains no points. |
| Returned bounds width and height may be larger or smaller than area affected |
| when Path is drawn. |
| |
| Includes Points associated with kMove_Verb that define empty |
| Contours. |
| |
| Behaves identically to getBounds when Path contains |
| only lines. If Path contains curves, computed bounds includes |
| the maximum extent of the Quad, Conic, or Cubic; is slower than getBounds; |
| and unlike getBounds, does not cache the result. |
| |
| #Return tight bounds of curves in Path ## |
| |
| #Example |
| auto debugster = [](const char* prefix, const SkPath& path) -> void { |
| const SkRect& bounds = path.computeTightBounds(); |
| SkDebugf("%s bounds = %g, %g, %g, %g\n", prefix, |
| bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom); |
| }; |
| SkPath path; |
| debugster("empty", path); |
| path.addCircle(50, 45, 25); |
| debugster("circle", path); |
| SkMatrix matrix; |
| matrix.setRotate(45, 50, 45); |
| path.transform(matrix); |
| debugster("rotated circle", path); |
| #StdOut |
| empty bounds = 0, 0, 0, 0 |
| circle bounds = 25, 20, 75, 70 |
| rotated circle bounds = 25, 20, 75, 70 |
| ## |
| ## |
| |
| #SeeAlso getBounds |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool conservativelyContainsRect(const SkRect& rect) const |
| #In Property |
| #Line # returns true if Rect may be inside ## |
| Returns true if rect is contained by Path. |
| May return false when rect is contained by Path. |
| |
| For now, only returns true if Path has one Contour and is convex. |
| rect may share points and edges with Path and be contained. |
| Returns true if rect is empty, that is, it has zero width or height; and |
| the Point or Line described by rect is contained by Path. |
| |
| #Param rect Rect, Line, or Point checked for containment ## |
| |
| #Return true if rect is contained ## |
| |
| #Example |
| #Height 140 |
| #Description |
| Rect is drawn in blue if it is contained by red Path. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPath path; |
| path.addRoundRect({10, 20, 54, 120}, 10, 20); |
| SkRect tests[] = { |
| { 10, 40, 54, 80 }, |
| { 25, 20, 39, 120 }, |
| { 15, 25, 49, 115 }, |
| { 13, 27, 51, 113 }, |
| }; |
| for (unsigned i = 0; i < SK_ARRAY_COUNT(tests); ++i) { |
| SkPaint paint; |
| paint.setColor(SK_ColorRED); |
| canvas->drawPath(path, paint); |
| bool rectInPath = path.conservativelyContainsRect(tests[i]); |
| paint.setColor(rectInPath ? SK_ColorBLUE : SK_ColorBLACK); |
| canvas->drawRect(tests[i], paint); |
| canvas->translate(64, 0); |
| } |
| } |
| ## |
| |
| #SeeAlso contains Op Rect Convexity |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void incReserve(unsigned extraPtCount) |
| #In Utility |
| #Line # reserves space for additional data ## |
| grows Path Verb_Array and Point_Array to contain extraPtCount additional Points. |
| May improve performance and use less memory by |
| reducing the number and size of allocations when creating Path. |
| |
| #Param extraPtCount number of additional Points to allocate ## |
| |
| #Example |
| #Height 192 |
| void draw(SkCanvas* canvas) { |
| auto addPoly = [](int sides, SkScalar size, SkPath* path) -> void { |
| path->moveTo(size, 0); |
| for (int i = 1; i < sides; i++) { |
| SkScalar c, s = SkScalarSinCos(SK_ScalarPI * 2 * i / sides, &c); |
| path->lineTo(c * size, s * size); |
| } |
| path->close(); |
| }; |
| SkPath path; |
| path.incReserve(3 + 4 + 5 + 6 + 7 + 8 + 9); |
| for (int sides = 3; sides < 10; ++sides) { |
| addPoly(sides, sides, &path); |
| } |
| SkMatrix matrix; |
| matrix.setScale(10, 10, -10, -10); |
| path.transform(matrix); |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso Point_Array |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Build |
| #Populate |
| #Line # adds points and verbs to path ## |
| ## |
| |
| #Method void moveTo(SkScalar x, SkScalar y) |
| #In Build |
| #Line # starts Contour ## |
| Adds beginning of Contour at Point (x, y). |
| |
| #Param x x-axis value of Contour start ## |
| #Param y y-axis value of Contour start ## |
| |
| #Example |
| #Width 140 |
| #Height 100 |
| void draw(SkCanvas* canvas) { |
| SkRect rect = { 20, 20, 120, 80 }; |
| SkPath path; |
| path.addRect(rect); |
| path.moveTo(rect.fLeft, rect.fTop); |
| path.lineTo(rect.fRight, rect.fBottom); |
| path.moveTo(rect.fLeft, rect.fBottom); |
| path.lineTo(rect.fRight, rect.fTop); |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso Contour lineTo rMoveTo quadTo conicTo cubicTo close() |
| |
| ## |
| |
| #Method void moveTo(const SkPoint& p) |
| |
| Adds beginning of Contour at Point p. |
| |
| #Param p contour start ## |
| |
| #Example |
| #Width 128 |
| #Height 128 |
| void draw(SkCanvas* canvas) { |
| SkPoint data[][3] = {{{30,40},{60,60},{90,30}}, {{30,120},{60,100},{90,120}}, |
| {{60,100},{60,40},{70,30}}, {{60,40},{50,20},{70,30}}}; |
| SkPath path; |
| for (unsigned i = 0; i < SK_ARRAY_COUNT(data); ++i) { |
| path.moveTo(data[i][0]); |
| path.lineTo(data[i][1]); |
| path.lineTo(data[i][2]); |
| } |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso Contour lineTo rMoveTo quadTo conicTo cubicTo close() |
| |
| ## |
| |
| #Method void rMoveTo(SkScalar dx, SkScalar dy) |
| #In Build |
| #Line # starts Contour relative to Last_Point ## |
| Adds beginning of Contour relative to Last_Point. |
| If Path is empty, starts Contour at (dx, dy). |
| Otherwise, start Contour at Last_Point offset by (dx, dy). |
| Function name stands for "relative move to". |
| |
| #Param dx offset from Last_Point to Contour start on x-axis ## |
| #Param dy offset from Last_Point to Contour start on y-axis ## |
| |
| #Example |
| #Height 100 |
| SkPath path; |
| path.addRect({20, 20, 80, 80}, SkPath::kCW_Direction, 2); |
| path.rMoveTo(25, 2); |
| SkVector arrow[] = {{0, -4}, {-20, 0}, {0, -3}, {-5, 5}, {5, 5}, {0, -3}, {20, 0}}; |
| for (unsigned i = 0; i < SK_ARRAY_COUNT(arrow); ++i) { |
| path.rLineTo(arrow[i].fX, arrow[i].fY); |
| } |
| SkPaint paint; |
| canvas->drawPath(path, paint); |
| SkPoint lastPt; |
| path.getLastPt(&lastPt); |
| canvas->drawString("start", lastPt.fX, lastPt.fY, paint); |
| ## |
| |
| #SeeAlso Contour lineTo moveTo quadTo conicTo cubicTo close() |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void lineTo(SkScalar x, SkScalar y) |
| #In Build |
| #Line # appends Line ## |
| Adds Line from Last_Point to (x, y). If Path is empty, or last Verb is |
| kClose_Verb, Last_Point is set to (0, 0) before adding Line. |
| |
| lineTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed. |
| lineTo then appends kLine_Verb to Verb_Array and (x, y) to Point_Array. |
| |
| #Param x end of added Line in x ## |
| #Param y end of added Line in y ## |
| |
| #Example |
| #Height 100 |
| ###$ |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setTextSize(72); |
| canvas->drawString("#", 120, 80, paint); |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setStrokeWidth(5); |
| SkPath path; |
| SkPoint hash[] = {{58, 28}, {43, 80}, {37, 45}, {85, 45}}; |
| SkVector offsets[] = {{0, 0}, {17, 0}, {0, 0}, {-5, 17}}; |
| unsigned o = 0; |
| for (unsigned i = 0; i < SK_ARRAY_COUNT(hash); i += 2) { |
| for (unsigned j = 0; j < 2; o++, j++) { |
| path.moveTo(hash[i].fX + offsets[o].fX, hash[i].fY + offsets[o].fY); |
| path.lineTo(hash[i + 1].fX + offsets[o].fX, hash[i + 1].fY + offsets[o].fY); |
| } |
| } |
| canvas->drawPath(path, paint); |
| } |
| $$$# |
| ## |
| |
| #SeeAlso Contour moveTo rLineTo addRect |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void lineTo(const SkPoint& p) |
| |
| Adds Line from Last_Point to Point p. If Path is empty, or last Verb is |
| kClose_Verb, Last_Point is set to (0, 0) before adding Line. |
| |
| lineTo first appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed. |
| lineTo then appends kLine_Verb to Verb_Array and Point p to Point_Array. |
| |
| #Param p end Point of added Line ## |
| |
| #Example |
| #Height 100 |
| SkPath path; |
| SkVector oxo[] = {{25, 25}, {35, 35}, {25, 35}, {35, 25}, |
| {40, 20}, {40, 80}, {60, 20}, {60, 80}, |
| {20, 40}, {80, 40}, {20, 60}, {80, 60}}; |
| for (unsigned i = 0; i < SK_ARRAY_COUNT(oxo); i += 2) { |
| path.moveTo(oxo[i]); |
| path.lineTo(oxo[i + 1]); |
| } |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| canvas->drawPath(path, paint); |
| ## |
| |
| #SeeAlso Contour moveTo rLineTo addRect |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void rLineTo(SkScalar dx, SkScalar dy) |
| #In Build |
| #Line # appends Line relative to Last_Point ## |
| Adds Line from Last_Point to Vector (dx, dy). If Path is empty, or last Verb is |
| kClose_Verb, Last_Point is set to (0, 0) before adding Line. |
| |
| Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed; |
| then appends kLine_Verb to Verb_Array and Line end to Point_Array. |
| Line end is Last_Point plus Vector (dx, dy). |
| Function name stands for "relative line to". |
| |
| #Param dx offset from Last_Point to Line end on x-axis ## |
| #Param dy offset from Last_Point to Line end on y-axis ## |
| |
| #Example |
| #Height 128 |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPath path; |
| path.moveTo(10, 98); |
| SkScalar x = 0, y = 0; |
| for (int i = 10; i < 100; i += 5) { |
| x += i * ((i & 2) - 1); |
| y += i * (((i + 1) & 2) - 1); |
| path.rLineTo(x, y); |
| |
| } |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso Contour moveTo lineTo addRect |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Quad |
| #Alias Quad ## |
| #Alias Quads ## |
| #Alias Quadratic_Bezier ## |
| #Alias Quadratic_Beziers ## |
| #Line # curve described by second-order polynomial ## |
| |
| Quad describes a quadratic Bezier, a second-order curve identical to a section |
| of a parabola. Quad begins at a start Point, curves towards a control Point, |
| and then curves to an end Point. |
| |
| #Example |
| #Height 110 |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPoint quadPts[] = {{20, 90}, {120, 10}, {220, 90}}; |
| canvas->drawLine(quadPts[0], quadPts[1], paint); |
| canvas->drawLine(quadPts[1], quadPts[2], paint); |
| SkPath path; |
| path.moveTo(quadPts[0]); |
| path.quadTo(quadPts[1], quadPts[2]); |
| paint.setStrokeWidth(3); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| Quad is a special case of Conic where Conic_Weight is set to one. |
| |
| Quad is always contained by the triangle connecting its three Points. Quad |
| begins tangent to the line between start Point and control Point, and ends |
| tangent to the line between control Point and end Point. |
| |
| #Example |
| #Height 160 |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPoint quadPts[] = {{20, 150}, {120, 10}, {220, 150}}; |
| SkColor colors[] = { 0xff88ff00, 0xff0088bb, 0xff6600cc, 0xffbb3377 }; |
| for (unsigned i = 0; i < SK_ARRAY_COUNT(colors); ++i) { |
| paint.setColor(0x7fffffff & colors[i]); |
| paint.setStrokeWidth(1); |
| canvas->drawLine(quadPts[0], quadPts[1], paint); |
| canvas->drawLine(quadPts[1], quadPts[2], paint); |
| SkPath path; |
| path.moveTo(quadPts[0]); |
| path.quadTo(quadPts[1], quadPts[2]); |
| paint.setStrokeWidth(3); |
| paint.setColor(colors[i]); |
| canvas->drawPath(path, paint); |
| quadPts[1].fY += 30; |
| } |
| } |
| ## |
| |
| #Method void quadTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2) |
| |
| #In Quad |
| #Line # appends Quad ## |
| Adds Quad from Last_Point towards (x1, y1), to (x2, y2). |
| If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0) |
| before adding Quad. |
| |
| Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed; |
| then appends kQuad_Verb to Verb_Array; and (x1, y1), (x2, y2) |
| to Point_Array. |
| |
| #Param x1 control Point of Quad in x ## |
| #Param y1 control Point of Quad in y ## |
| #Param x2 end Point of Quad in x ## |
| #Param y2 end Point of Quad in y ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPath path; |
| path.moveTo(0, -10); |
| for (int i = 0; i < 128; i += 16) { |
| path.quadTo( 10 + i, -10 - i, 10 + i, 0); |
| path.quadTo( 14 + i, 14 + i, 0, 14 + i); |
| path.quadTo(-18 - i, 18 + i, -18 - i, 0); |
| path.quadTo(-22 - i, -22 - i, 0, -22 - i); |
| } |
| path.offset(128, 128); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso Contour moveTo conicTo rQuadTo |
| |
| ## |
| |
| #Method void quadTo(const SkPoint& p1, const SkPoint& p2) |
| #In Build |
| #In Quad |
| Adds Quad from Last_Point towards Point p1, to Point p2. |
| If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0) |
| before adding Quad. |
| |
| Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed; |
| then appends kQuad_Verb to Verb_Array; and Points p1, p2 |
| to Point_Array. |
| |
| #Param p1 control Point of added Quad ## |
| #Param p2 end Point of added Quad ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setAntiAlias(true); |
| SkPath path; |
| SkPoint pts[] = {{128, 10}, {10, 214}, {236, 214}}; |
| path.moveTo(pts[1]); |
| for (int i = 0; i < 3; ++i) { |
| path.quadTo(pts[i % 3], pts[(i + 2) % 3]); |
| } |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso Contour moveTo conicTo rQuadTo |
| |
| ## |
| |
| #Method void rQuadTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2) |
| #In Build |
| #In Quad |
| #Line # appends Quad relative to Last_Point ## |
| Adds Quad from Last_Point towards Vector (dx1, dy1), to Vector (dx2, dy2). |
| If Path is empty, or last Verb |
| is kClose_Verb, Last_Point is set to (0, 0) before adding Quad. |
| |
| Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, |
| if needed; then appends kQuad_Verb to Verb_Array; and appends Quad |
| control and Quad end to Point_Array. |
| Quad control is Last_Point plus Vector (dx1, dy1). |
| Quad end is Last_Point plus Vector (dx2, dy2). |
| Function name stands for "relative quad to". |
| |
| #Param dx1 offset from Last_Point to Quad control on x-axis ## |
| #Param dy1 offset from Last_Point to Quad control on y-axis ## |
| #Param dx2 offset from Last_Point to Quad end on x-axis ## |
| #Param dy2 offset from Last_Point to Quad end on y-axis ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| SkPath path; |
| path.moveTo(128, 20); |
| path.rQuadTo(-6, 10, -7, 10); |
| for (int i = 1; i < 32; i += 4) { |
| path.rQuadTo(10 + i, 10 + i, 10 + i * 4, 10); |
| path.rQuadTo(-10 - i, 10 + i, -10 - (i + 2) * 4, 10); |
| } |
| path.quadTo(92, 220, 128, 215); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso Contour moveTo conicTo quadTo |
| |
| ## |
| |
| #Subtopic Quad ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Subtopic Conic |
| #Line # conic section defined by three points and a weight ## |
| #Alias Conics ## |
| |
| Conic describes a conical section: a piece of an ellipse, or a piece of a |
| parabola, or a piece of a hyperbola. Conic begins at a start Point, |
| curves towards a control Point, and then curves to an end Point. The influence |
| of the control Point is determined by Conic_Weight. |
| |
| Each Conic in Path adds two Points and one Conic_Weight. Conic_Weights in Path |
| may be inspected with Iter, or with RawIter. |
| |
| #Subtopic Weight |
| #Alias Conic_Weights ## |
| #Alias Weights ## |
| #Line # strength of Conic control Point ## |
| |
| Weight determines both the strength of the control Point and the type of Conic. |
| Weight varies from zero to infinity. At zero, Weight causes the control Point to |
| have no effect; Conic is identical to a line segment from start Point to end |
| point. If Weight is less than one, Conic follows an elliptical arc. |
| If Weight is exactly one, then Conic is identical to Quad; Conic follows a |
| parabolic arc. If Weight is greater than one, Conic follows a hyperbolic |
| arc. If Weight is infinity, Conic is identical to two line segments, connecting |
| start Point to control Point, and control Point to end Point. |
| |
| #Example |
| #Description |
| When Conic_Weight is one, Quad is added to path; the two are identical. |
| ## |
| void draw(SkCanvas* canvas) { |
| const char* verbNames[] = { "move", "line", "quad", "conic", "cubic", "close", "done" }; |
| const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 }; |
| SkPath path; |
| path.conicTo(20, 30, 50, 60, 1); |
| SkPath::Iter iter(path, false); |
| SkPath::Verb verb; |
| do { |
| SkPoint points[4]; |
| verb = iter.next(points); |
| SkDebugf("%s ", verbNames[(int) verb]); |
| for (int i = 0; i < pointCount[(int) verb]; ++i) { |
| SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY); |
| } |
| if (SkPath::kConic_Verb == verb) { |
| SkDebugf("weight = %g", iter.conicWeight()); |
| } |
| SkDebugf("\n"); |
| } while (SkPath::kDone_Verb != verb); |
| } |
| #StdOut |
| move {0, 0}, |
| quad {0, 0}, {20, 30}, {50, 60}, |
| done |
| ## |
| ## |
| |
| If weight is less than one, Conic is an elliptical segment. |
| |
| #Example |
| #Description |
| A 90 degree circular arc has the weight |
| #Formula |
| 1 / sqrt(2) |
| ## |
| . |
| ## |
| void draw(SkCanvas* canvas) { |
| const char* verbNames[] = { "move", "line", "quad", "conic", "cubic", "close", "done" }; |
| const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 }; |
| SkPath path; |
| path.arcTo(20, 0, 20, 20, 20); |
| SkPath::Iter iter(path, false); |
| SkPath::Verb verb; |
| do { |
| SkPoint points[4]; |
| verb = iter.next(points); |
| SkDebugf("%s ", verbNames[(int) verb]); |
| for (int i = 0; i < pointCount[(int) verb]; ++i) { |
| SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY); |
| } |
| if (SkPath::kConic_Verb == verb) { |
| SkDebugf("weight = %g", iter.conicWeight()); |
| } |
| SkDebugf("\n"); |
| } while (SkPath::kDone_Verb != verb); |
| } |
| #StdOut |
| move {0, 0}, |
| conic {0, 0}, {20, 0}, {20, 20}, weight = 0.707107 |
| done |
| ## |
| ## |
| |
| If weight is greater than one, Conic is a hyperbolic segment. As weight gets large, |
| a hyperbolic segment can be approximated by straight lines connecting the |
| control Point with the end Points. |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| const char* verbNames[] = { "move", "line", "quad", "conic", "cubic", "close", "done" }; |
| const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 }; |
| SkPath path; |
| path.conicTo(20, 0, 20, 20, SK_ScalarInfinity); |
| SkPath::Iter iter(path, false); |
| SkPath::Verb verb; |
| do { |
| SkPoint points[4]; |
| verb = iter.next(points); |
| SkDebugf("%s ", verbNames[(int) verb]); |
| for (int i = 0; i < pointCount[(int) verb]; ++i) { |
| SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY); |
| } |
| if (SkPath::kConic_Verb == verb) { |
| SkDebugf("weight = %g", iter.conicWeight()); |
| } |
| SkDebugf("\n"); |
| } while (SkPath::kDone_Verb != verb); |
| } |
| #StdOut |
| move {0, 0}, |
| line {0, 0}, {20, 0}, |
| line {20, 0}, {20, 20}, |
| done |
| ## |
| ## |
| |
| #Subtopic Weight ## |
| |
| #Method void conicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, |
| SkScalar w) |
| #In Conic |
| #In Build |
| #Line # appends Conic ## |
| |
| Adds Conic from Last_Point towards (x1, y1), to (x2, y2), weighted by w. |
| If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0) |
| before adding Conic. |
| |
| Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed. |
| |
| If w is finite and not one, appends kConic_Verb to Verb_Array; |
| and (x1, y1), (x2, y2) to Point_Array; and w to Conic_Weights. |
| |
| If w is one, appends kQuad_Verb to Verb_Array, and |
| (x1, y1), (x2, y2) to Point_Array. |
| |
| If w is not finite, appends kLine_Verb twice to Verb_Array, and |
| (x1, y1), (x2, y2) to Point_Array. |
| |
| #Param x1 control Point of Conic in x ## |
| #Param y1 control Point of Conic in y ## |
| #Param x2 end Point of Conic in x ## |
| #Param y2 end Point of Conic in y ## |
| #Param w weight of added Conic ## |
| |
| #Example |
| #Height 160 |
| #Description |
| As weight increases, curve is pulled towards control point. |
| The bottom two curves are elliptical; the next is parabolic; the |
| top curve is hyperbolic. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPoint conicPts[] = {{20, 150}, {120, 10}, {220, 150}}; |
| canvas->drawLine(conicPts[0], conicPts[1], paint); |
| canvas->drawLine(conicPts[1], conicPts[2], paint); |
| SkColor colors[] = { 0xff88ff00, 0xff0088bb, 0xff6600cc, 0xffbb3377 }; |
| paint.setStrokeWidth(3); |
| SkScalar weight = 0.5f; |
| for (unsigned i = 0; i < SK_ARRAY_COUNT(colors); ++i) { |
| SkPath path; |
| path.moveTo(conicPts[0]); |
| path.conicTo(conicPts[1], conicPts[2], weight); |
| paint.setColor(colors[i]); |
| canvas->drawPath(path, paint); |
| weight += 0.25f; |
| } |
| } |
| ## |
| |
| #SeeAlso rConicTo arcTo addArc quadTo |
| |
| ## |
| |
| #Method void conicTo(const SkPoint& p1, const SkPoint& p2, SkScalar w) |
| #In Build |
| #In Conic |
| Adds Conic from Last_Point towards Point p1, to Point p2, weighted by w. |
| If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0) |
| before adding Conic. |
| |
| Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed. |
| |
| If w is finite and not one, appends kConic_Verb to Verb_Array; |
| and Points p1, p2 to Point_Array; and w to Conic_Weights. |
| |
| If w is one, appends kQuad_Verb to Verb_Array, and Points p1, p2 |
| to Point_Array. |
| |
| If w is not finite, appends kLine_Verb twice to Verb_Array, and |
| Points p1, p2 to Point_Array. |
| |
| #Param p1 control Point of added Conic ## |
| #Param p2 end Point of added Conic ## |
| #Param w weight of added Conic ## |
| |
| #Example |
| #Height 128 |
| #Description |
| Conics and arcs use identical representations. As the arc sweep increases |
| the Conic_Weight also increases, but remains smaller than one. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkRect oval = {0, 20, 120, 140}; |
| SkPath path; |
| for (int i = 0; i < 4; ++i) { |
| path.moveTo(oval.centerX(), oval.fTop); |
| path.arcTo(oval, -90, 90 - 20 * i, false); |
| oval.inset(15, 15); |
| } |
| path.offset(100, 0); |
| SkScalar conicWeights[] = { 0.707107f, 0.819152f, 0.906308f, 0.965926f }; |
| SkPoint conicPts[][3] = { { {40, 20}, {100, 20}, {100, 80} }, |
| { {40, 35}, {71.509f, 35}, {82.286f, 64.6091f} }, |
| { {40, 50}, {53.9892f, 50}, {62.981f, 60.7164f} }, |
| { {40, 65}, {44.0192f, 65}, {47.5f, 67.0096f} } }; |
| for (int i = 0; i < 4; ++i) { |
| path.moveTo(conicPts[i][0]); |
| path.conicTo(conicPts[i][1], conicPts[i][2], conicWeights[i]); |
| } |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso rConicTo arcTo addArc quadTo |
| |
| ## |
| |
| #Method void rConicTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2, |
| SkScalar w) |
| #In Build |
| #In Conic |
| #Line # appends Conic relative to Last_Point ## |
| |
| Adds Conic from Last_Point towards Vector (dx1, dy1), to Vector (dx2, dy2), |
| weighted by w. If Path is empty, or last Verb |
| is kClose_Verb, Last_Point is set to (0, 0) before adding Conic. |
| |
| Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, |
| if needed. |
| |
| If w is finite and not one, next appends kConic_Verb to Verb_Array, |
| and w is recorded as Conic_Weight; otherwise, if w is one, appends |
| kQuad_Verb to Verb_Array; or if w is not finite, appends kLine_Verb |
| twice to Verb_Array. |
| |
| In all cases appends Points control and end to Point_Array. |
| control is Last_Point plus Vector (dx1, dy1). |
| end is Last_Point plus Vector (dx2, dy2). |
| |
| Function name stands for "relative conic to". |
| |
| #Param dx1 offset from Last_Point to Conic control on x-axis ## |
| #Param dy1 offset from Last_Point to Conic control on y-axis ## |
| #Param dx2 offset from Last_Point to Conic end on x-axis ## |
| #Param dy2 offset from Last_Point to Conic end on y-axis ## |
| #Param w weight of added Conic ## |
| |
| #Example |
| #Height 140 |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPath path; |
| path.moveTo(20, 80); |
| path.rConicTo( 60, 0, 60, 60, 0.707107f); |
| path.rConicTo( 0, -60, 60, -60, 0.707107f); |
| path.rConicTo(-60, 0, -60, -60, 0.707107f); |
| path.rConicTo( 0, 60, -60, 60, 0.707107f); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso conicTo arcTo addArc quadTo |
| |
| ## |
| |
| #Subtopic Conic ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Cubic |
| #Alias Cubic ## |
| #Alias Cubics ## |
| #Alias Cubic_Bezier ## |
| #Alias Cubic_Beziers ## |
| #Line # curve described by third-order polynomial ## |
| |
| Cubic describes a Bezier_Curve segment described by a third-order polynomial. |
| Cubic begins at a start Point, curving towards the first control Point; |
| and curves from the end Point towards the second control Point. |
| |
| #Example |
| #Height 160 |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPoint cubicPts[] = {{20, 150}, {90, 10}, {160, 150}, {230, 10}}; |
| SkColor colors[] = { 0xff88ff00, 0xff0088bb, 0xff6600cc, 0xffbb3377 }; |
| for (unsigned i = 0; i < SK_ARRAY_COUNT(colors); ++i) { |
| paint.setColor(0x7fffffff & colors[i]); |
| paint.setStrokeWidth(1); |
| for (unsigned j = 0; j < 3; ++j) { |
| canvas->drawLine(cubicPts[j], cubicPts[j + 1], paint); |
| } |
| SkPath path; |
| path.moveTo(cubicPts[0]); |
| path.cubicTo(cubicPts[1], cubicPts[2], cubicPts[3]); |
| paint.setStrokeWidth(3); |
| paint.setColor(colors[i]); |
| canvas->drawPath(path, paint); |
| cubicPts[1].fY += 30; |
| cubicPts[2].fX += 30; |
| } |
| } |
| ## |
| |
| #Method void cubicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, |
| SkScalar x3, SkScalar y3) |
| #In Build |
| #In Cubic |
| #Line # appends Cubic ## |
| |
| Adds Cubic from Last_Point towards (x1, y1), then towards (x2, y2), ending at |
| (x3, y3). If Path is empty, or last Verb is kClose_Verb, Last_Point is set to |
| (0, 0) before adding Cubic. |
| |
| Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed; |
| then appends kCubic_Verb to Verb_Array; and (x1, y1), (x2, y2), (x3, y3) |
| to Point_Array. |
| |
| #Param x1 first control Point of Cubic in x ## |
| #Param y1 first control Point of Cubic in y ## |
| #Param x2 second control Point of Cubic in x ## |
| #Param y2 second control Point of Cubic in y ## |
| #Param x3 end Point of Cubic in x ## |
| #Param y3 end Point of Cubic in y ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPath path; |
| path.moveTo(0, -10); |
| for (int i = 0; i < 128; i += 16) { |
| SkScalar c = i * 0.5f; |
| path.cubicTo( 10 + c, -10 - i, 10 + i, -10 - c, 10 + i, 0); |
| path.cubicTo( 14 + i, 14 + c, 14 + c, 14 + i, 0, 14 + i); |
| path.cubicTo(-18 - c, 18 + i, -18 - i, 18 + c, -18 - i, 0); |
| path.cubicTo(-22 - i, -22 - c, -22 - c, -22 - i, 0, -22 - i); |
| } |
| path.offset(128, 128); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso Contour moveTo rCubicTo quadTo |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void cubicTo(const SkPoint& p1, const SkPoint& p2, const SkPoint& p3) |
| |
| #In Build |
| #In Cubic |
| Adds Cubic from Last_Point towards Point p1, then towards Point p2, ending at |
| Point p3. If Path is empty, or last Verb is kClose_Verb, Last_Point is set to |
| (0, 0) before adding Cubic. |
| |
| Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed; |
| then appends kCubic_Verb to Verb_Array; and Points p1, p2, p3 |
| to Point_Array. |
| |
| #Param p1 first control Point of Cubic ## |
| #Param p2 second control Point of Cubic ## |
| #Param p3 end Point of Cubic ## |
| |
| #Example |
| #Height 84 |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPoint pts[] = { {20, 20}, {300, 80}, {-140, 90}, {220, 10} }; |
| SkPath path; |
| path.moveTo(pts[0]); |
| path.cubicTo(pts[1], pts[2], pts[3]); |
| canvas->drawPath(path, paint); |
| ## |
| |
| #SeeAlso Contour moveTo rCubicTo quadTo |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void rCubicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, |
| SkScalar x3, SkScalar y3) |
| #In Build |
| #In Cubic |
| #Line # appends Cubic relative to Last_Point ## |
| |
| Adds Cubic from Last_Point towards Vector (dx1, dy1), then towards |
| Vector (dx2, dy2), to Vector (dx3, dy3). |
| If Path is empty, or last Verb |
| is kClose_Verb, Last_Point is set to (0, 0) before adding Cubic. |
| |
| Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, |
| if needed; then appends kCubic_Verb to Verb_Array; and appends Cubic |
| control and Cubic end to Point_Array. |
| Cubic control is Last_Point plus Vector (dx1, dy1). |
| Cubic end is Last_Point plus Vector (dx2, dy2). |
| Function name stands for "relative cubic to". |
| |
| #Param x1 offset from Last_Point to first Cubic control on x-axis ## |
| #Param y1 offset from Last_Point to first Cubic control on y-axis ## |
| #Param x2 offset from Last_Point to second Cubic control on x-axis ## |
| #Param y2 offset from Last_Point to second Cubic control on y-axis ## |
| #Param x3 offset from Last_Point to Cubic end on x-axis ## |
| #Param y3 offset from Last_Point to Cubic end on y-axis ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPath path; |
| path.moveTo(24, 108); |
| for (int i = 0; i < 16; i++) { |
| SkScalar sx, sy; |
| sx = SkScalarSinCos(i * SK_ScalarPI / 8, &sy); |
| path.rCubicTo(40 * sx, 4 * sy, 4 * sx, 40 * sy, 40 * sx, 40 * sy); |
| } |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso Contour moveTo cubicTo quadTo |
| |
| ## |
| |
| #Subtopic Cubic ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Subtopic Arc |
| #Line # part of Oval or Circle ## |
| Arc can be constructed in a number of ways. Arc may be described by part of Oval and angles, |
| by start point and end point, and by radius and tangent lines. Each construction has advantages, |
| and some constructions correspond to Arc drawing in graphics standards. |
| |
| All Arc draws are implemented by one or more Conic draws. When Conic_Weight is less than one, |
| Conic describes an Arc of some Oval or Circle. |
| |
| arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo) |
| describes Arc as a piece of Oval, beginning at start angle, sweeping clockwise or counterclockwise, |
| which may continue Contour or start a new one. This construction is similar to PostScript and |
| HTML_Canvas arcs. Variation addArc always starts new Contour. Canvas::drawArc draws without |
| requiring Path. |
| |
| arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius) |
| describes Arc as tangent to the line (x0, y0), (x1, y1) and tangent to the line (x1, y1), (x2, y2) |
| where (x0, y0) is the last Point added to Path. This construction is similar to PostScript and |
| HTML_Canvas arcs. |
| |
| arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep, |
| SkScalar x, SkScalar y) |
| describes Arc as part of Oval with radii (rx, ry), beginning at |
| last Point added to Path and ending at (x, y). More than one Arc satisfies this criteria, |
| so additional values choose a single solution. This construction is similar to SVG arcs. |
| |
| conicTo describes Arc of less than 180 degrees as a pair of tangent lines and Conic_Weight. |
| conicTo can represent any Arc with a sweep less than 180 degrees at any rotation. All arcTo |
| constructions are converted to Conic data when added to Path. |
| |
| #ToDo allow example to hide source and not be exposed as fiddle since markdown / html can't |
| do the kind of table shown in the illustration. |
| example is spaced correctly on fiddle but spacing is too wide on pc |
| ## |
| |
| #Example |
| #Height 300 |
| #Width 600 |
| #Description |
| #List |
| # <sup>1</sup> arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo) ## |
| # <sup>2</sup> parameter sets force MoveTo ## |
| # <sup>3</sup> start angle must be multiple of 90 degrees ## |
| # <sup>4</sup> arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius) ## |
| # <sup>5</sup> arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc, |
| Direction sweep, SkScalar x, SkScalar y) ## |
| #List ## |
| #Description ## |
| #Function |
| ###$ |
| struct data { |
| const char* name; |
| char super; |
| int yn[10]; |
| }; |
| |
| const data dataSet[] = { |
| { "arcTo sweep", '1', {1, 3, 1, 0, 0, 0, 0, 1, 0, 0 }}, |
| { "drawArc", 0, {1, -1, 1, 1, 1, 1, 1, 0, 0, 0 }}, |
| { "addArc", 0, {1, 1, 1, 4, 0, 1, 1, 1, 0, 0 }}, |
| { "arcTo tangents", '4', {0, 0, 0, 0, 0, 0, 0, 1, 1, 0 }}, |
| { "arcTo radii", '5', {1, 0, 1, 0, 0, 0, 0, 1, 1, 0 }}, |
| { "conicTo", 0, {1, 1, 0, 0, 0, 0, 0, 1, 1, 1 }} |
| }; |
| |
| #define __degree_symbol__ "\xC2" "\xB0" |
| |
| const char* headers[] = { |
| "Oval part", |
| "force moveTo", |
| "can draw 180" __degree_symbol__, |
| "can draw 360" __degree_symbol__, |
| "can draw greater than 360" __degree_symbol__, |
| "ignored if radius is zero", |
| "ignored if sweep is zero", |
| "requires Path", |
| "describes rotation", |
| "describes perspective", |
| }; |
| |
| const char* yna[] = { |
| "n/a", |
| "no", |
| "yes" |
| }; |
| $$$# |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint lp; |
| lp.setAntiAlias(true); |
| SkPaint tp(lp); |
| SkPaint sp(tp); |
| SkPaint bp(tp); |
| bp.setFakeBoldText(true); |
| sp.setTextSize(10); |
| lp.setColor(SK_ColorGRAY); |
| canvas->translate(0, 32); |
| const int tl = 115; |
| for (unsigned col = 0; col <= SK_ARRAY_COUNT(headers); ++col) { |
| canvas->drawLine(tl + col * 35, 100, tl + col * 35, 250, lp); |
| if (0 == col) { |
| continue; |
| } |
| canvas->drawLine(tl + col * 35, 100, tl + 100 + col * 35, 0, lp); |
| SkPath path; |
| path.moveTo(tl - 3 + col * 35, 103); |
| path.lineTo(tl + 124 + col * 35, -24); |
| canvas->drawTextOnPathHV(headers[col -1], strlen(headers[col -1]), path, 0, -9, bp); |
| } |
| for (unsigned row = 0; row <= SK_ARRAY_COUNT(dataSet); ++row) { |
| if (0 == row) { |
| canvas->drawLine(tl, 100, tl + 350, 100, lp); |
| } else { |
| canvas->drawLine(5, 100 + row * 25, tl + 350, 100 + row * 25, lp); |
| } |
| if (row == SK_ARRAY_COUNT(dataSet)) { |
| break; |
| } |
| canvas->drawString(dataSet[row].name, 5, 117 + row * 25, bp); |
| if (dataSet[row].super) { |
| SkScalar width = bp.measureText(dataSet[row].name, strlen(dataSet[row].name)); |
| canvas->drawText(&dataSet[row].super, 1, 8 + width, 112 + row * 25, sp); |
| } |
| for (unsigned col = 0; col < SK_ARRAY_COUNT(headers); ++col) { |
| int val = dataSet[row].yn[col]; |
| canvas->drawString(yna[SkTMin(2, val + 1)], tl + 5 + col * 35, 117 + row * 25, tp); |
| if (val > 1) { |
| char supe = '0' + val - 1; |
| canvas->drawText(&supe, 1, tl + 25 + col * 35, 112 + row * 25, sp); |
| } |
| } |
| } |
| } |
| #Example ## |
| |
| #Example |
| #Height 128 |
| #Description |
| #ToDo make this a list or table ## |
| 1 describes an arc from an oval, a starting angle, and a sweep angle. |
| 2 is similar to 1, but does not require building a path to draw. |
| 3 is similar to 1, but always begins new Contour. |
| 4 describes an arc from a pair of tangent lines and a radius. |
| 5 describes an arc from Oval center, arc start Point and arc end Point. |
| 6 describes an arc from a pair of tangent lines and a Conic_Weight. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkRect oval = {8, 8, 56, 56}; |
| SkPaint ovalPaint; |
| ovalPaint.setAntiAlias(true); |
| SkPaint textPaint(ovalPaint); |
| ovalPaint.setStyle(SkPaint::kStroke_Style); |
| SkPaint arcPaint(ovalPaint); |
| arcPaint.setStrokeWidth(5); |
| arcPaint.setColor(SK_ColorBLUE); |
| canvas->translate(-64, 0); |
| for (char arcStyle = '1'; arcStyle <= '6'; ++arcStyle) { |
| '4' == arcStyle ? canvas->translate(-96, 55) : canvas->translate(64, 0); |
| canvas->drawText(&arcStyle, 1, 30, 36, textPaint); |
| canvas->drawOval(oval, ovalPaint); |
| SkPath path; |
| path.moveTo({56, 32}); |
| switch (arcStyle) { |
| case '1': |
| path.arcTo(oval, 0, 90, false); |
| break; |
| case '2': |
| canvas->drawArc(oval, 0, 90, false, arcPaint); |
| continue; |
| case '3': |
| path.addArc(oval, 0, 90); |
| break; |
| case '4': |
| path.arcTo({56, 56}, {32, 56}, 24); |
| break; |
| case '5': |
| path.arcTo({24, 24}, 0, SkPath::kSmall_ArcSize, SkPath::kCW_Direction, {32, 56}); |
| break; |
| case '6': |
| path.conicTo({56, 56}, {32, 56}, SK_ScalarRoot2Over2); |
| break; |
| } |
| canvas->drawPath(path, arcPaint); |
| } |
| } |
| #Example ## |
| |
| |
| #Method void arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo) |
| #In Build |
| #In Arc |
| #Line # appends Arc ## |
| Append Arc to Path. Arc added is part of ellipse |
| bounded by oval, from startAngle through sweepAngle. Both startAngle and |
| sweepAngle are measured in degrees, where zero degrees is aligned with the |
| positive x-axis, and positive sweeps extends Arc clockwise. |
| |
| arcTo adds Line connecting Path last Point to initial Arc Point if forceMoveTo |
| is false and Path is not empty. Otherwise, added Contour begins with first point |
| of Arc. Angles greater than -360 and less than 360 are treated modulo 360. |
| |
| #Param oval bounds of ellipse containing Arc ## |
| #Param startAngle starting angle of Arc in degrees ## |
| #Param sweepAngle sweep, in degrees. Positive is clockwise; treated modulo 360 ## |
| #Param forceMoveTo true to start a new contour with Arc ## |
| |
| #Example |
| #Height 200 |
| #Description |
| arcTo continues a previous contour when forceMoveTo is false and when Path |
| is not empty. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| SkPath path; |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setStrokeWidth(4); |
| path.moveTo(0, 0); |
| path.arcTo({20, 20, 120, 120}, -90, 90, false); |
| canvas->drawPath(path, paint); |
| path.rewind(); |
| path.arcTo({120, 20, 220, 120}, -90, 90, false); |
| canvas->drawPath(path, paint); |
| path.rewind(); |
| path.moveTo(0, 0); |
| path.arcTo({20, 120, 120, 220}, -90, 90, true); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso addArc SkCanvas::drawArc conicTo |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius) |
| #In Build |
| #In Arc |
| Append Arc to Path, after appending Line if needed. Arc is implemented by Conic |
| weighted to describe part of Circle. Arc is contained by tangent from |
| last Path point (x0, y0) to (x1, y1), and tangent from (x1, y1) to (x2, y2). Arc |
| is part of Circle sized to radius, positioned so it touches both tangent lines. |
| |
| #ToDo allow example to hide source and not be exposed as fiddle ## |
| |
| #Example |
| #Height 226 |
| void draw(SkCanvas* canvas) { |
| SkPaint tangentPaint; |
| tangentPaint.setAntiAlias(true); |
| SkPaint textPaint(tangentPaint); |
| tangentPaint.setStyle(SkPaint::kStroke_Style); |
| tangentPaint.setColor(SK_ColorGRAY); |
| SkPaint arcPaint(tangentPaint); |
| arcPaint.setStrokeWidth(5); |
| arcPaint.setColor(SK_ColorBLUE); |
| SkPath path; |
| SkPoint pts[] = { {56, 20}, {200, 20}, {90, 190} }; |
| SkScalar radius = 50; |
| path.moveTo(pts[0]); |
| path.arcTo(pts[1], pts[2], radius); |
| canvas->drawLine(pts[0], pts[1], tangentPaint); |
| canvas->drawLine(pts[1], pts[2], tangentPaint); |
| SkPoint lastPt; |
| (void) path.getLastPt(&lastPt); |
| SkVector radial = pts[2] - pts[1]; |
| radial.setLength(radius); |
| SkPoint center = { lastPt.fX - radial.fY, lastPt.fY + radial.fX }; |
| canvas->drawCircle(center, radius, tangentPaint); |
| canvas->drawLine(lastPt, center, tangentPaint); |
| radial = pts[1] - pts[0]; |
| radial.setLength(radius); |
| SkPoint arcStart = { center.fX + radial.fY, center.fY - radial.fX }; |
| canvas->drawLine(center, arcStart, tangentPaint); |
| canvas->drawPath(path, arcPaint); |
| textPaint.setTextAlign(SkPaint::kRight_Align); |
| canvas->drawString("(x0, y0)", pts[0].fX - 5, pts[0].fY, textPaint); |
| textPaint.setTextAlign(SkPaint::kLeft_Align); |
| canvas->drawString("(x1, y1)", pts[1].fX + 5, pts[1].fY, textPaint); |
| textPaint.setTextAlign(SkPaint::kCenter_Align); |
| canvas->drawString("(x2, y2)", pts[2].fX, pts[2].fY + 15, textPaint); |
| textPaint.setTextAlign(SkPaint::kRight_Align); |
| canvas->drawString("radius", center.fX + 15, center.fY + 25, textPaint); |
| canvas->drawString("radius", center.fX - 3, center.fY - 16, textPaint); |
| } |
| ## |
| |
| If last Path Point does not start Arc, arcTo appends connecting Line to Path. |
| The length of Vector from (x1, y1) to (x2, y2) does not affect Arc. |
| |
| #Example |
| #Height 128 |
| void draw(SkCanvas* canvas) { |
| SkPaint tangentPaint; |
| tangentPaint.setAntiAlias(true); |
| SkPaint textPaint(tangentPaint); |
| tangentPaint.setStyle(SkPaint::kStroke_Style); |
| tangentPaint.setColor(SK_ColorGRAY); |
| SkPaint arcPaint(tangentPaint); |
| arcPaint.setStrokeWidth(5); |
| arcPaint.setColor(SK_ColorBLUE); |
| SkPath path; |
| SkPoint pts[] = { {156, 20}, {200, 20}, {170, 50} }; |
| SkScalar radius = 50; |
| path.moveTo(pts[0]); |
| path.arcTo(pts[1], pts[2], radius); |
| canvas->drawLine(pts[0], pts[1], tangentPaint); |
| canvas->drawLine(pts[1], pts[2], tangentPaint); |
| SkPoint lastPt; |
| (void) path.getLastPt(&lastPt); |
| SkVector radial = pts[2] - pts[1]; |
| radial.setLength(radius); |
| SkPoint center = { lastPt.fX - radial.fY, lastPt.fY + radial.fX }; |
| canvas->drawLine(lastPt, center, tangentPaint); |
| radial = pts[1] - pts[0]; |
| radial.setLength(radius); |
| SkPoint arcStart = { center.fX + radial.fY, center.fY - radial.fX }; |
| canvas->drawLine(center, arcStart, tangentPaint); |
| canvas->drawPath(path, arcPaint); |
| textPaint.setTextAlign(SkPaint::kCenter_Align); |
| canvas->drawString("(x0, y0)", pts[0].fX, pts[0].fY - 7, textPaint); |
| textPaint.setTextAlign(SkPaint::kLeft_Align); |
| canvas->drawString("(x1, y1)", pts[1].fX + 5, pts[1].fY, textPaint); |
| textPaint.setTextAlign(SkPaint::kCenter_Align); |
| canvas->drawString("(x2, y2)", pts[2].fX, pts[2].fY + 15, textPaint); |
| textPaint.setTextAlign(SkPaint::kRight_Align); |
| canvas->drawString("radius", center.fX + 15, center.fY + 25, textPaint); |
| canvas->drawString("radius", center.fX - 5, center.fY - 20, textPaint); |
| } |
| ## |
| |
| Arc sweep is always less than 180 degrees. If radius is zero, or if |
| tangents are nearly parallel, arcTo appends Line from last Path Point to (x1, y1). |
| |
| arcTo appends at most one Line and one Conic. |
| arcTo implements the functionality of PostScript_Arct and HTML_Canvas_ArcTo. |
| |
| #Param x1 x-axis value common to pair of tangents ## |
| #Param y1 y-axis value common to pair of tangents ## |
| #Param x2 x-axis value end of second tangent ## |
| #Param y2 y-axis value end of second tangent ## |
| #Param radius distance from Arc to Circle center ## |
| |
| #Example |
| #Description |
| arcTo is represented by Line and circular Conic in Path. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPath path; |
| path.moveTo({156, 20}); |
| path.arcTo(200, 20, 170, 50, 50); |
| SkPath::Iter iter(path, false); |
| SkPoint p[4]; |
| SkPath::Verb verb; |
| while (SkPath::kDone_Verb != (verb = iter.next(p))) { |
| switch (verb) { |
| case SkPath::kMove_Verb: |
| SkDebugf("move to (%g,%g)\n", p[0].fX, p[0].fY); |
| break; |
| case SkPath::kLine_Verb: |
| SkDebugf("line (%g,%g),(%g,%g)\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY); |
| break; |
| case SkPath::kConic_Verb: |
| SkDebugf("conic (%g,%g),(%g,%g),(%g,%g) weight %g\n", |
| p[0].fX, p[0].fY, p[1].fX, p[1].fY, p[2].fX, p[2].fY, iter.conicWeight()); |
| break; |
| default: |
| SkDebugf("unexpected verb\n"); |
| } |
| } |
| } |
| #StdOut |
| move to (156,20) |
| line (156,20),(79.2893,20) |
| conic (79.2893,20),(200,20),(114.645,105.355) weight 0.382683 |
| ## |
| ## |
| |
| #SeeAlso conicTo |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void arcTo(const SkPoint p1, const SkPoint p2, SkScalar radius) |
| #In Build |
| #In Arc |
| Append Arc to Path, after appending Line if needed. Arc is implemented by Conic |
| weighted to describe part of Circle. Arc is contained by tangent from |
| last Path point to p1, and tangent from p1 to p2. Arc |
| is part of Circle sized to radius, positioned so it touches both tangent lines. |
| |
| If last Path Point does not start Arc, arcTo appends connecting Line to Path. |
| The length of Vector from p1 to p2 does not affect Arc. |
| |
| Arc sweep is always less than 180 degrees. If radius is zero, or if |
| tangents are nearly parallel, arcTo appends Line from last Path Point to p1. |
| |
| arcTo appends at most one Line and one Conic. |
| arcTo implements the functionality of PostScript_Arct and HTML_Canvas_ArcTo. |
| |
| #Param p1 Point common to pair of tangents ## |
| #Param p2 end of second tangent ## |
| #Param radius distance from Arc to Circle center ## |
| |
| #Example |
| #Description |
| Because tangent lines are parallel, arcTo appends line from last Path Point to |
| p1, but does not append a circular Conic. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPath path; |
| path.moveTo({156, 20}); |
| path.arcTo({200, 20}, {170, 20}, 50); |
| SkPath::Iter iter(path, false); |
| SkPoint p[4]; |
| SkPath::Verb verb; |
| while (SkPath::kDone_Verb != (verb = iter.next(p))) { |
| switch (verb) { |
| case SkPath::kMove_Verb: |
| SkDebugf("move to (%g,%g)\n", p[0].fX, p[0].fY); |
| break; |
| case SkPath::kLine_Verb: |
| SkDebugf("line (%g,%g),(%g,%g)\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY); |
| break; |
| case SkPath::kConic_Verb: |
| SkDebugf("conic (%g,%g),(%g,%g),(%g,%g) weight %g\n", |
| p[0].fX, p[0].fY, p[1].fX, p[1].fY, p[2].fX, p[2].fY, iter.conicWeight()); |
| break; |
| default: |
| SkDebugf("unexpected verb\n"); |
| } |
| } |
| } |
| #StdOut |
| move to (156,20) |
| line (156,20),(200,20) |
| ## |
| ## |
| |
| #SeeAlso conicTo |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Enum ArcSize |
| #Line # used by arcTo variation ## |
| |
| #Code |
| enum ArcSize { |
| kSmall_ArcSize, |
| kLarge_ArcSize, |
| }; |
| ## |
| |
| Four Oval parts with radii (rx, ry) start at last Path Point and ends at (x, y). |
| ArcSize and Direction select one of the four Oval parts. |
| |
| #Const kSmall_ArcSize 0 |
| #Line # smaller of Arc pair ## |
| ## |
| #Const kLarge_ArcSize 1 |
| #Line # larger of Arc pair ## |
| ## |
| |
| #Example |
| #Height 160 |
| #Description |
| Arc begins at top of Oval pair and ends at bottom. Arc can take four routes to get there. |
| Two routes are large, and two routes are counterclockwise. The one route both large |
| and counterclockwise is blue. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| for (auto sweep: { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) { |
| for (auto arcSize : { SkPath::kSmall_ArcSize, SkPath::kLarge_ArcSize } ) { |
| SkPath path; |
| path.moveTo({120, 50}); |
| path.arcTo(70, 40, 30, arcSize, sweep, 156, 100); |
| if (SkPath::kCCW_Direction == sweep && SkPath::kLarge_ArcSize == arcSize) { |
| paint.setColor(SK_ColorBLUE); |
| paint.setStrokeWidth(3); |
| } |
| canvas->drawPath(path, paint); |
| } |
| } |
| } |
| ## |
| |
| #SeeAlso arcTo Direction |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc, |
| Direction sweep, SkScalar x, SkScalar y) |
| #In Build |
| #In Arc |
| |
| Append Arc to Path. Arc is implemented by one or more Conics weighted to |
| describe part of Oval with radii (rx, ry) rotated by xAxisRotate degrees. Arc |
| curves from last Path Point to (x, y), choosing one of four possible routes: |
| clockwise or counterclockwise, and smaller or larger. |
| |
| Arc sweep is always less than 360 degrees. arcTo appends Line to (x, y) if |
| either radii are zero, or if last Path Point equals (x, y). arcTo scales radii |
| (rx, ry) to fit last Path Point and (x, y) if both are greater than zero but |
| too small. |
| |
| arcTo appends up to four Conic curves. |
| arcTo implements the functionality of SVG_Arc, although SVG "sweep-flag" value |
| is opposite the integer value of sweep; SVG "sweep-flag" uses 1 for clockwise, |
| while kCW_Direction cast to int is zero. |
| |
| #Param rx radius in x before x-axis rotation ## |
| #Param ry radius in y before x-axis rotation ## |
| #Param xAxisRotate x-axis rotation in degrees; positive values are clockwise ## |
| #Param largeArc chooses smaller or larger Arc ## |
| #Param sweep chooses clockwise or counterclockwise Arc ## |
| #Param x end of Arc ## |
| #Param y end of Arc ## |
| |
| #Example |
| #Height 160 |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| for (auto sweep: { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) { |
| for (auto arcSize : { SkPath::kSmall_ArcSize, SkPath::kLarge_ArcSize } ) { |
| SkPath path; |
| path.moveTo({120, 50}); |
| path.arcTo(70, 40, 30, arcSize, sweep, 120.1, 50); |
| if (SkPath::kCCW_Direction == sweep && SkPath::kLarge_ArcSize == arcSize) { |
| paint.setColor(SK_ColorBLUE); |
| paint.setStrokeWidth(3); |
| } |
| canvas->drawPath(path, paint); |
| } |
| } |
| } |
| ## |
| |
| #SeeAlso rArcTo ArcSize Direction |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void arcTo(const SkPoint r, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep, |
| const SkPoint xy) |
| #In Build |
| #In Arc |
| |
| Append Arc to Path. Arc is implemented by one or more Conic weighted to describe part of Oval |
| with radii (r.fX, r.fY) rotated by xAxisRotate degrees. Arc curves from last Path Point to |
| (xy.fX, xy.fY), choosing one of four possible routes: clockwise or counterclockwise, |
| and smaller or larger. |
| |
| Arc sweep is always less than 360 degrees. arcTo appends Line to xy if either radii are zero, |
| or if last Path Point equals (x, y). arcTo scales radii r to fit last Path Point and |
| xy if both are greater than zero but too small to describe an arc. |
| |
| arcTo appends up to four Conic curves. |
| arcTo implements the functionality of SVG_Arc, although SVG "sweep-flag" value is |
| opposite the integer value of sweep; SVG "sweep-flag" uses 1 for clockwise, while |
| kCW_Direction cast to int is zero. |
| |
| #Param r radii on axes before x-axis rotation ## |
| #Param xAxisRotate x-axis rotation in degrees; positive values are clockwise ## |
| #Param largeArc chooses smaller or larger Arc ## |
| #Param sweep chooses clockwise or counterclockwise Arc ## |
| #Param xy end of Arc ## |
| |
| #Example |
| #Height 108 |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| SkPath path; |
| const SkPoint starts[] = {{20, 20}, {120, 20}, {70, 60}}; |
| for (auto start : starts) { |
| path.moveTo(start.fX, start.fY); |
| path.rArcTo(20, 20, 0, SkPath::kSmall_ArcSize, SkPath::kCCW_Direction, 60, 0); |
| } |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso rArcTo ArcSize Direction |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void rArcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc, |
| Direction sweep, SkScalar dx, SkScalar dy) |
| #In Build |
| #In Arc |
| #Line # appends Arc relative to Last_Point ## |
| |
| Append Arc to Path, relative to last Path Point. Arc is implemented by one or |
| more Conic, weighted to describe part of Oval with radii (rx, ry) rotated by |
| xAxisRotate degrees. Arc curves from last Path Point (x0, y0) to end Point: |
| |
| #Formula |
| (x0 + dx, y0 + dy) |
| ## |
| , choosing one of four possible routes: clockwise or |
| counterclockwise, and smaller or larger. If Path is empty, the start Arc Point |
| is (0, 0). |
| |
| Arc sweep is always less than 360 degrees. arcTo appends Line to end Point |
| if either radii are zero, or if last Path Point equals end Point. |
| arcTo scales radii (rx, ry) to fit last Path Point and end Point if both are |
| greater than zero but too small to describe an arc. |
| |
| arcTo appends up to four Conic curves. |
| arcTo implements the functionality of SVG_Arc, although SVG "sweep-flag" value is |
| opposite the integer value of sweep; SVG "sweep-flag" uses 1 for clockwise, while |
| kCW_Direction cast to int is zero. |
| |
| #Param rx radius before x-axis rotation ## |
| #Param ry radius before x-axis rotation ## |
| #Param xAxisRotate x-axis rotation in degrees; positive values are clockwise ## |
| #Param largeArc chooses smaller or larger Arc ## |
| #Param sweep chooses clockwise or counterclockwise Arc ## |
| #Param dx x-axis offset end of Arc from last Path Point ## |
| #Param dy y-axis offset end of Arc from last Path Point ## |
| |
| #Example |
| #Height 108 |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| SkPath path; |
| const SkPoint starts[] = {{20, 20}, {120, 20}, {70, 60}}; |
| for (auto start : starts) { |
| path.moveTo(start.fX, start.fY); |
| path.rArcTo(20, 20, 0, SkPath::kSmall_ArcSize, SkPath::kCCW_Direction, 60, 0); |
| } |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso arcTo ArcSize Direction |
| |
| ## |
| |
| #Subtopic Arc ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void close() |
| #In Build |
| #Line # makes last Contour a loop ## |
| Append kClose_Verb to Path. A closed Contour connects the first and last Point |
| with Line, forming a continuous loop. Open and closed Contour draw the same |
| with SkPaint::kFill_Style. With SkPaint::kStroke_Style, open Contour draws |
| Paint_Stroke_Cap at Contour start and end; closed Contour draws |
| Paint_Stroke_Join at Contour start and end. |
| |
| close() has no effect if Path is empty or last Path Verb is kClose_Verb. |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setStrokeWidth(15); |
| paint.setStrokeCap(SkPaint::kRound_Cap); |
| SkPath path; |
| const SkPoint points[] = {{20, 20}, {70, 20}, {40, 90}}; |
| path.addPoly(points, SK_ARRAY_COUNT(points), false); |
| for (int loop = 0; loop < 2; ++loop) { |
| for (auto style : {SkPaint::kStroke_Style, SkPaint::kFill_Style, |
| SkPaint::kStrokeAndFill_Style} ) { |
| paint.setStyle(style); |
| canvas->drawPath(path, paint); |
| canvas->translate(85, 0); |
| } |
| path.close(); |
| canvas->translate(-255, 128); |
| } |
| } |
| ## |
| |
| #SeeAlso |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static bool IsInverseFillType(FillType fill) |
| #In Property |
| #Line # returns if Fill_Type represents outside geometry ## |
| Returns true if fill is inverted and Path with fill represents area outside |
| of its geometric bounds. |
| |
| #Table |
| #Legend |
| # FillType # is inverse ## |
| ## |
| # kWinding_FillType # false ## |
| # kEvenOdd_FillType # false ## |
| # kInverseWinding_FillType # true ## |
| # kInverseEvenOdd_FillType # true ## |
| ## |
| |
| #Param fill one of: kWinding_FillType, kEvenOdd_FillType, |
| kInverseWinding_FillType, kInverseEvenOdd_FillType |
| ## |
| |
| #Return true if Path fills outside its bounds ## |
| |
| #Example |
| #Function |
| ###$ |
| #define nameValue(fill) { SkPath::fill, #fill } |
| |
| $$$# |
| ## |
| void draw(SkCanvas* canvas) { |
| struct { |
| SkPath::FillType fill; |
| const char* name; |
| } fills[] = { |
| nameValue(kWinding_FillType), |
| nameValue(kEvenOdd_FillType), |
| nameValue(kInverseWinding_FillType), |
| nameValue(kInverseEvenOdd_FillType), |
| }; |
| for (auto fill: fills ) { |
| SkDebugf("IsInverseFillType(%s) == %s\n", fill.name, SkPath::IsInverseFillType(fill.fill) ? |
| "true" : "false"); |
| } |
| } |
| #StdOut |
| IsInverseFillType(kWinding_FillType) == false |
| IsInverseFillType(kEvenOdd_FillType) == false |
| IsInverseFillType(kInverseWinding_FillType) == true |
| IsInverseFillType(kInverseEvenOdd_FillType) == true |
| ## |
| ## |
| |
| #SeeAlso FillType getFillType setFillType ConvertToNonInverseFillType |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static FillType ConvertToNonInverseFillType(FillType fill) |
| #In Utility |
| #Line # returns Fill_Type representing inside geometry ## |
| Returns equivalent Fill_Type representing Path fill inside its bounds. |
| . |
| |
| #Table |
| #Legend |
| # FillType # inside FillType ## |
| ## |
| # kWinding_FillType # kWinding_FillType ## |
| # kEvenOdd_FillType # kEvenOdd_FillType ## |
| # kInverseWinding_FillType # kWinding_FillType ## |
| # kInverseEvenOdd_FillType # kEvenOdd_FillType ## |
| ## |
| |
| #Param fill one of: kWinding_FillType, kEvenOdd_FillType, |
| kInverseWinding_FillType, kInverseEvenOdd_FillType |
| ## |
| |
| #Return fill, or kWinding_FillType or kEvenOdd_FillType if fill is inverted ## |
| |
| #Example |
| #Function |
| ###$ |
| #define nameValue(fill) { SkPath::fill, #fill } |
| |
| $$$# |
| ## |
| void draw(SkCanvas* canvas) { |
| struct { |
| SkPath::FillType fill; |
| const char* name; |
| } fills[] = { |
| nameValue(kWinding_FillType), |
| nameValue(kEvenOdd_FillType), |
| nameValue(kInverseWinding_FillType), |
| nameValue(kInverseEvenOdd_FillType), |
| }; |
| for (unsigned i = 0; i < SK_ARRAY_COUNT(fills); ++i) { |
| if (fills[i].fill != (SkPath::FillType) i) { |
| SkDebugf("fills array order does not match FillType enum order"); |
| break; |
| } |
| SkDebugf("ConvertToNonInverseFillType(%s) == %s\n", fills[i].name, |
| fills[(int) SkPath::ConvertToNonInverseFillType(fills[i].fill)].name); |
| } |
| } |
| #StdOut |
| ConvertToNonInverseFillType(kWinding_FillType) == kWinding_FillType |
| ConvertToNonInverseFillType(kEvenOdd_FillType) == kEvenOdd_FillType |
| ConvertToNonInverseFillType(kInverseWinding_FillType) == kWinding_FillType |
| ConvertToNonInverseFillType(kInverseEvenOdd_FillType) == kEvenOdd_FillType |
| ## |
| ## |
| |
| #SeeAlso FillType getFillType setFillType IsInverseFillType |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static int ConvertConicToQuads(const SkPoint& p0, const SkPoint& p1, const SkPoint& p2, |
| SkScalar w, SkPoint pts[], int pow2) |
| #In Utility |
| #Line # approximates Conic with Quad array ## |
| |
| Approximates Conic with Quad array. Conic is constructed from start Point p0, |
| control Point p1, end Point p2, and weight w. |
| Quad array is stored in pts; this storage is supplied by caller. |
| Maximum Quad count is 2 to the pow2. |
| Every third point in array shares last Point of previous Quad and first Point of |
| next Quad. Maximum pts storage size is given by: |
| #Formula |
| (1 + 2 * (1 << pow2)) * sizeof(SkPoint) |
| ## |
| . |
| |
| Returns Quad count used the approximation, which may be smaller |
| than the number requested. |
| |
| Conic_Weight determines the amount of influence Conic control point has on the curve. |
| w less than one represents an elliptical section. w greater than one represents |
| a hyperbolic section. w equal to one represents a parabolic section. |
| |
| Two Quad curves are sufficient to approximate an elliptical Conic with a sweep |
| of up to 90 degrees; in this case, set pow2 to one. |
| |
| #Param p0 Conic start Point ## |
| #Param p1 Conic control Point ## |
| #Param p2 Conic end Point ## |
| #Param w Conic weight ## |
| #Param pts storage for Quad array ## |
| #Param pow2 Quad count, as power of two, normally 0 to 5 (1 to 32 Quad curves) ## |
| |
| #Return number of Quad curves written to pts ## |
| |
| #Example |
| #Description |
| A pair of Quad curves are drawn in red on top of the elliptical Conic curve in black. |
| The middle curve is nearly circular. The top-right curve is parabolic, which can |
| be drawn exactly with a single Quad. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint conicPaint; |
| conicPaint.setAntiAlias(true); |
| conicPaint.setStyle(SkPaint::kStroke_Style); |
| SkPaint quadPaint(conicPaint); |
| quadPaint.setColor(SK_ColorRED); |
| SkPoint conic[] = { {20, 170}, {80, 170}, {80, 230} }; |
| for (auto weight : { .25f, .5f, .707f, .85f, 1.f } ) { |
| SkPoint quads[5]; |
| SkPath::ConvertConicToQuads(conic[0], conic[1], conic[2], weight, quads, 1); |
| SkPath path; |
| path.moveTo(conic[0]); |
| path.conicTo(conic[1], conic[2], weight); |
| canvas->drawPath(path, conicPaint); |
| path.rewind(); |
| path.moveTo(quads[0]); |
| path.quadTo(quads[1], quads[2]); |
| path.quadTo(quads[3], quads[4]); |
| canvas->drawPath(path, quadPaint); |
| canvas->translate(50, -50); |
| } |
| } |
| ## |
| |
| #SeeAlso Conic Quad |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isRect(SkRect* rect, bool* isClosed = nullptr, Direction* direction = nullptr) const |
| #In Property |
| #Line # returns if describes Rect ## |
| Returns true if Path is equivalent to Rect when filled. |
| If false: rect, isClosed, and direction are unchanged. |
| If true: rect, isClosed, and direction are written to if not nullptr. |
| |
| rect may be smaller than the Path bounds. Path bounds may include kMove_Verb points |
| that do not alter the area drawn by the returned rect. |
| |
| #Param rect storage for bounds of Rect; may be nullptr ## |
| #Param isClosed storage set to true if Path is closed; may be nullptr ## |
| #Param direction storage set to Rect direction; may be nullptr ## |
| |
| #Return true if Path contains Rect ## |
| |
| #Example |
| #Description |
| After addRect, isRect returns true. Following moveTo permits isRect to return true, but |
| following lineTo does not. addPoly returns true even though rect is not closed, and one |
| side of rect is made up of consecutive line segments. |
| ## |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& path) -> void { |
| SkRect rect; |
| SkPath::Direction direction; |
| bool isClosed; |
| path.isRect(&rect, &isClosed, &direction) ? |
| SkDebugf("%s is rect (%g, %g, %g, %g); is %s" "closed; direction %s\n", prefix, |
| rect.fLeft, rect.fTop, rect.fRight, rect.fBottom, isClosed ? "" : "not ", |
| SkPath::kCW_Direction == direction ? "CW" : "CCW") : |
| SkDebugf("%s is not rect\n", prefix); |
| }; |
| SkPath path; |
| debugster("empty", path); |
| path.addRect({10, 20, 30, 40}); |
| debugster("addRect", path); |
| path.moveTo(60, 70); |
| debugster("moveTo", path); |
| path.lineTo(60, 70); |
| debugster("lineTo", path); |
| path.reset(); |
| const SkPoint pts[] = { {0, 0}, {0, 80}, {80, 80}, {80, 0}, {40, 0}, {20, 0} }; |
| path.addPoly(pts, SK_ARRAY_COUNT(pts), false); |
| debugster("addPoly", path); |
| } |
| #StdOut |
| empty is not rect |
| addRect is rect (10, 20, 30, 40); is closed; direction CW |
| moveTo is rect (10, 20, 30, 40); is closed; direction CW |
| lineTo is not rect |
| addPoly is rect (0, 0, 80, 80); is not closed; direction CCW |
| ## |
| ## |
| |
| #SeeAlso computeTightBounds conservativelyContainsRect getBounds isConvex isLastContourClosed isNestedFillRects |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isNestedFillRects(SkRect rect[2], Direction dirs[2] = nullptr) const |
| #In Property |
| #Line # returns if describes Rect pair, one inside the other ## |
| Returns true if Path is equivalent to nested Rect pair when filled. |
| If false, rect and dirs are unchanged. |
| If true, rect and dirs are written to if not nullptr: |
| setting rect[0] to outer Rect, and rect[1] to inner Rect; |
| setting dirs[0] to Direction of outer Rect, and dirs[1] to Direction of inner |
| Rect. |
| |
| #Param rect storage for Rect pair; may be nullptr ## |
| #Param dirs storage for Direction pair; may be nullptr ## |
| |
| #Return true if Path contains nested Rect pair ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setStrokeWidth(5); |
| SkPath path; |
| path.addRect({10, 20, 30, 40}); |
| paint.getFillPath(path, &path); |
| SkRect rects[2]; |
| SkPath::Direction directions[2]; |
| if (path.isNestedFillRects(rects, directions)) { |
| for (int i = 0; i < 2; ++i) { |
| SkDebugf("%s (%g, %g, %g, %g); direction %s\n", i ? "inner" : "outer", |
| rects[i].fLeft, rects[i].fTop, rects[i].fRight, rects[i].fBottom, |
| SkPath::kCW_Direction == directions[i] ? "CW" : "CCW"); |
| } |
| } else { |
| SkDebugf("is not nested rectangles\n"); |
| } |
| } |
| #StdOut |
| outer (7.5, 17.5, 32.5, 42.5); direction CW |
| inner (12.5, 22.5, 27.5, 37.5); direction CCW |
| ## |
| ## |
| |
| #SeeAlso computeTightBounds conservativelyContainsRect getBounds isConvex isLastContourClosed isRect |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addRect(const SkRect& rect, Direction dir = kCW_Direction) |
| #In Build |
| #Line # adds one Contour containing Rect ## |
| Add Rect to Path, appending kMove_Verb, three kLine_Verb, and kClose_Verb, |
| starting with top-left corner of Rect; followed by top-right, bottom-right, |
| and bottom-left if dir is kCW_Direction; or followed by bottom-left, |
| bottom-right, and top-right if dir is kCCW_Direction. |
| |
| #Param rect Rect to add as a closed contour ## |
| #Param dir Direction to wind added contour ## |
| |
| #Example |
| #Description |
| The left Rect dashes starting at the top-left corner, to the right. |
| The right Rect dashes starting at the top-left corner, towards the bottom. |
| ## |
| #Height 128 |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setStrokeWidth(15); |
| paint.setStrokeCap(SkPaint::kSquare_Cap); |
| float intervals[] = { 5, 21.75f }; |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setPathEffect(SkDashPathEffect::Make(intervals, SK_ARRAY_COUNT(intervals), 0)); |
| SkPath path; |
| path.addRect({20, 20, 100, 100}, SkPath::kCW_Direction); |
| canvas->drawPath(path, paint); |
| path.rewind(); |
| path.addRect({140, 20, 220, 100}, SkPath::kCCW_Direction); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso SkCanvas::drawRect Direction |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addRect(const SkRect& rect, Direction dir, unsigned start) |
| |
| Add Rect to Path, appending kMove_Verb, three kLine_Verb, and kClose_Verb. |
| If dir is kCW_Direction, Rect corners are added clockwise; if dir is |
| kCCW_Direction, Rect corners are added counterclockwise. |
| start determines the first corner added. |
| |
| #Table |
| #Legend |
| # start # first corner ## |
| #Legend ## |
| # 0 # top-left ## |
| # 1 # top-right ## |
| # 2 # bottom-right ## |
| # 3 # bottom-left ## |
| #Table ## |
| |
| #Param rect Rect to add as a closed contour ## |
| #Param dir Direction to wind added contour ## |
| #Param start initial corner of Rect to add ## |
| |
| #Example |
| #Height 128 |
| #Description |
| The arrow is just after the initial corner and points towards the next |
| corner appended to Path. |
| ## |
| void draw(SkCanvas* canvas) { |
| const SkPoint arrow[] = { {5, -5}, {15, -5}, {20, 0}, {15, 5}, {5, 5}, {10, 0} }; |
| const SkRect rect = {10, 10, 54, 54}; |
| SkPaint rectPaint; |
| rectPaint.setAntiAlias(true); |
| rectPaint.setStyle(SkPaint::kStroke_Style); |
| SkPaint arrowPaint(rectPaint); |
| SkPath arrowPath; |
| arrowPath.addPoly(arrow, SK_ARRAY_COUNT(arrow), true); |
| arrowPaint.setPathEffect(SkPath1DPathEffect::Make(arrowPath, 176, 0, |
| SkPath1DPathEffect::kRotate_Style)); |
| for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) { |
| for (unsigned start : { 0, 1, 2, 3 } ) { |
| SkPath path; |
| path.addRect(rect, direction, start); |
| canvas->drawPath(path, rectPaint); |
| canvas->drawPath(path, arrowPaint); |
| canvas->translate(64, 0); |
| } |
| canvas->translate(-256, 64); |
| } |
| } |
| ## |
| |
| #SeeAlso SkCanvas::drawRect Direction |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addRect(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom, |
| Direction dir = kCW_Direction) |
| |
| Add Rect (left, top, right, bottom) to Path, |
| appending kMove_Verb, three kLine_Verb, and kClose_Verb, |
| starting with top-left corner of Rect; followed by top-right, bottom-right, |
| and bottom-left if dir is kCW_Direction; or followed by bottom-left, |
| bottom-right, and top-right if dir is kCCW_Direction. |
| |
| #Param left smaller x-axis value of Rect ## |
| #Param top smaller y-axis value of Rect ## |
| #Param right larger x-axis value of Rect ## |
| #Param bottom larger y-axis value of Rect ## |
| #Param dir Direction to wind added contour ## |
| |
| #Example |
| #Description |
| The left Rect dashes start at the top-left corner, and continue to the right. |
| The right Rect dashes start at the top-left corner, and continue down. |
| ## |
| #Height 128 |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setStrokeWidth(15); |
| paint.setStrokeCap(SkPaint::kSquare_Cap); |
| float intervals[] = { 5, 21.75f }; |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setPathEffect(SkDashPathEffect::Make(intervals, SK_ARRAY_COUNT(intervals), 0)); |
| for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) { |
| SkPath path; |
| path.addRect(20, 20, 100, 100, direction); |
| canvas->drawPath(path, paint); |
| canvas->translate(128, 0); |
| } |
| } |
| ## |
| |
| #SeeAlso SkCanvas::drawRect Direction |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addOval(const SkRect& oval, Direction dir = kCW_Direction) |
| #In Build |
| #Line # adds one Contour containing Oval ## |
| Add Oval to path, appending kMove_Verb, four kConic_Verb, and kClose_Verb. |
| Oval is upright ellipse bounded by Rect oval with radii equal to half oval width |
| and half oval height. Oval begins at (oval.fRight, oval.centerY()) and continues |
| clockwise if dir is kCW_Direction, counterclockwise if dir is kCCW_Direction. |
| |
| #Param oval bounds of ellipse added ## |
| #Param dir Direction to wind ellipse ## |
| |
| #Example |
| #Height 120 |
| SkPaint paint; |
| SkPath oval; |
| oval.addOval({20, 20, 160, 80}); |
| canvas->drawPath(oval, paint); |
| ## |
| |
| #SeeAlso SkCanvas::drawOval Direction Oval |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addOval(const SkRect& oval, Direction dir, unsigned start) |
| |
| Add Oval to Path, appending kMove_Verb, four kConic_Verb, and kClose_Verb. |
| Oval is upright ellipse bounded by Rect oval with radii equal to half oval width |
| and half oval height. Oval begins at start and continues |
| clockwise if dir is kCW_Direction, counterclockwise if dir is kCCW_Direction. |
| |
| #Table |
| #Legend |
| # start # Point ## |
| #Legend ## |
| # 0 # oval.centerX(), oval.fTop ## |
| # 1 # oval.fRight, oval.centerY() ## |
| # 2 # oval.centerX(), oval.fBottom ## |
| # 3 # oval.fLeft, oval.centerY() ## |
| #Table ## |
| |
| #Param oval bounds of ellipse added ## |
| #Param dir Direction to wind ellipse ## |
| #Param start index of initial point of ellipse ## |
| |
| #Example |
| #Height 160 |
| void draw(SkCanvas* canvas) { |
| const SkPoint arrow[] = { {0, -5}, {10, 0}, {0, 5} }; |
| const SkRect rect = {10, 10, 54, 54}; |
| SkPaint ovalPaint; |
| ovalPaint.setAntiAlias(true); |
| SkPaint textPaint(ovalPaint); |
| textPaint.setTextAlign(SkPaint::kCenter_Align); |
| ovalPaint.setStyle(SkPaint::kStroke_Style); |
| SkPaint arrowPaint(ovalPaint); |
| SkPath arrowPath; |
| arrowPath.addPoly(arrow, SK_ARRAY_COUNT(arrow), true); |
| arrowPaint.setPathEffect(SkPath1DPathEffect::Make(arrowPath, 176, 0, |
| SkPath1DPathEffect::kRotate_Style)); |
| for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) { |
| for (unsigned start : { 0, 1, 2, 3 } ) { |
| SkPath path; |
| path.addOval(rect, direction, start); |
| canvas->drawPath(path, ovalPaint); |
| canvas->drawPath(path, arrowPaint); |
| canvas->drawText(&"0123"[start], 1, rect.centerX(), rect.centerY() + 5, textPaint); |
| canvas->translate(64, 0); |
| } |
| canvas->translate(-256, 72); |
| canvas->drawString(SkPath::kCW_Direction == direction ? "clockwise" : "counterclockwise", |
| 128, 0, textPaint); |
| } |
| } |
| ## |
| |
| #SeeAlso SkCanvas::drawOval Direction Oval |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addCircle(SkScalar x, SkScalar y, SkScalar radius, |
| Direction dir = kCW_Direction) |
| #In Build |
| #Line # adds one Contour containing Circle ## |
| |
| Add Circle centered at (x, y) of size radius to Path, appending kMove_Verb, |
| four kConic_Verb, and kClose_Verb. Circle begins at: |
| #Formula |
| (x + radius, y) |
| ## |
| , continuing |
| clockwise if dir is kCW_Direction, and counterclockwise if dir is kCCW_Direction. |
| |
| Has no effect if radius is zero or negative. |
| |
| #Param x center of Circle ## |
| #Param y center of Circle ## |
| #Param radius distance from center to edge ## |
| #Param dir Direction to wind Circle ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setStrokeWidth(10); |
| for (int size = 10; size < 300; size += 20) { |
| SkPath path; |
| path.addCircle(128, 128, size, SkPath::kCW_Direction); |
| canvas->drawPath(path, paint); |
| } |
| } |
| ## |
| |
| #SeeAlso SkCanvas::drawCircle Direction Circle |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addArc(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle) |
| #In Build |
| #Line # adds one Contour containing Arc ## |
| Append Arc to Path, as the start of new Contour. Arc added is part of ellipse |
| bounded by oval, from startAngle through sweepAngle. Both startAngle and |
| sweepAngle are measured in degrees, where zero degrees is aligned with the |
| positive x-axis, and positive sweeps extends Arc clockwise. |
| |
| If sweepAngle <= -360, or sweepAngle >= 360; and startAngle modulo 90 is nearly |
| zero, append Oval instead of Arc. Otherwise, sweepAngle values are treated |
| modulo 360, and Arc may or may not draw depending on numeric rounding. |
| |
| #Param oval bounds of ellipse containing Arc ## |
| #Param startAngle starting angle of Arc in degrees ## |
| #Param sweepAngle sweep, in degrees. Positive is clockwise; treated modulo 360 ## |
| |
| #Example |
| #Description |
| The middle row of the left and right columns draw differently from the entries |
| above and below because sweepAngle is outside of the range of +/-360, |
| and startAngle modulo 90 is not zero. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| for (auto start : { 0, 90, 135, 180, 270 } ) { |
| for (auto sweep : { -450.f, -180.f, -90.f, 90.f, 180.f, 360.1f } ) { |
| SkPath path; |
| path.addArc({10, 10, 35, 45}, start, sweep); |
| canvas->drawPath(path, paint); |
| canvas->translate(252 / 6, 0); |
| } |
| canvas->translate(-252, 255 / 5); |
| } |
| } |
| ## |
| |
| #SeeAlso Arc arcTo SkCanvas::drawArc |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, |
| Direction dir = kCW_Direction) |
| #In Build |
| #Line # adds one Contour containing Round_Rect with common corner radii ## |
| |
| Append Round_Rect to Path, creating a new closed Contour. Round_Rect has bounds |
| equal to rect; each corner is 90 degrees of an ellipse with radii (rx, ry). If |
| dir is kCW_Direction, Round_Rect starts at top-left of the lower-left corner and |
| winds clockwise. If dir is kCCW_Direction, Round_Rect starts at the bottom-left |
| of the upper-left corner and winds counterclockwise. |
| |
| If either rx or ry is too large, rx and ry are scaled uniformly until the |
| corners fit. If rx or ry is less than or equal to zero, addRoundRect appends |
| Rect rect to Path. |
| |
| After appending, Path may be empty, or may contain: Rect, Oval, or RoundRect. |
| |
| #Param rect bounds of Round_Rect ## |
| #Param rx x-axis radius of rounded corners on the Round_Rect ## |
| #Param ry y-axis radius of rounded corners on the Round_Rect ## |
| #Param dir Direction to wind Round_Rect ## |
| |
| #Example |
| #Description |
| If either radius is zero, path contains Rect and is drawn red. |
| If sides are only radii, path contains Oval and is drawn blue. |
| All remaining path draws are convex, and are drawn in gray; no |
| paths constructed from addRoundRect are concave, so none are |
| drawn in green. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| for (auto xradius : { 0, 7, 13, 20 } ) { |
| for (auto yradius : { 0, 9, 18, 40 } ) { |
| SkPath path; |
| path.addRoundRect({10, 10, 36, 46}, xradius, yradius); |
| paint.setColor(path.isRect(nullptr) ? SK_ColorRED : path.isOval(nullptr) ? |
| SK_ColorBLUE : path.isConvex() ? SK_ColorGRAY : SK_ColorGREEN); |
| canvas->drawPath(path, paint); |
| canvas->translate(64, 0); |
| } |
| canvas->translate(-256, 64); |
| } |
| } |
| ## |
| |
| #SeeAlso addRRect SkCanvas::drawRoundRect |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addRoundRect(const SkRect& rect, const SkScalar radii[], |
| Direction dir = kCW_Direction) |
| |
| Append Round_Rect to Path, creating a new closed Contour. Round_Rect has bounds |
| equal to rect; each corner is 90 degrees of an ellipse with radii from the |
| array. |
| |
| #Table |
| #Legend |
| # radii index # location ## |
| #Legend ## |
| # 0 # x-axis radius of top-left corner ## |
| # 1 # y-axis radius of top-left corner ## |
| # 2 # x-axis radius of top-right corner ## |
| # 3 # y-axis radius of top-right corner ## |
| # 4 # x-axis radius of bottom-right corner ## |
| # 5 # y-axis radius of bottom-right corner ## |
| # 6 # x-axis radius of bottom-left corner ## |
| # 7 # y-axis radius of bottom-left corner ## |
| #Table ## |
| |
| If dir is kCW_Direction, Round_Rect starts at top-left of the lower-left corner |
| and winds clockwise. If dir is kCCW_Direction, Round_Rect starts at the |
| bottom-left of the upper-left corner and winds counterclockwise. |
| |
| If both radii on any side of rect exceed its length, all radii are scaled |
| uniformly until the corners fit. If either radius of a corner is less than or |
| equal to zero, both are treated as zero. |
| |
| After appending, Path may be empty, or may contain: Rect, Oval, or RoundRect. |
| |
| #Param rect bounds of Round_Rect ## |
| #Param radii array of 8 SkScalar values, a radius pair for each corner ## |
| #Param dir Direction to wind Round_Rect ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| SkScalar radii[] = { 80, 100, 0, 0, 40, 60, 0, 0 }; |
| SkPath path; |
| SkMatrix rotate90; |
| rotate90.setRotate(90, 128, 128); |
| for (int i = 0; i < 4; ++i) { |
| path.addRoundRect({10, 10, 110, 110}, radii); |
| path.transform(rotate90); |
| } |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso addRRect SkCanvas::drawRoundRect |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addRRect(const SkRRect& rrect, Direction dir = kCW_Direction) |
| #In Build |
| #Line # adds one Contour containing Round_Rect ## |
| Add rrect to Path, creating a new closed Contour. If |
| dir is kCW_Direction, rrect starts at top-left of the lower-left corner and |
| winds clockwise. If dir is kCCW_Direction, rrect starts at the bottom-left |
| of the upper-left corner and winds counterclockwise. |
| |
| After appending, Path may be empty, or may contain: Rect, Oval, or Round_Rect. |
| |
| #Param rrect bounds and radii of rounded rectangle ## |
| #Param dir Direction to wind Round_Rect ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| SkRRect rrect; |
| SkVector radii[] = {{50, 50}, {0, 0}, {0, 0}, {50, 50}}; |
| rrect.setRectRadii({10, 10, 110, 110}, radii); |
| SkPath path; |
| SkMatrix rotate90; |
| rotate90.setRotate(90, 128, 128); |
| for (int i = 0; i < 4; ++i) { |
| path.addRRect(rrect); |
| path.transform(rotate90); |
| } |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso addRoundRect SkCanvas::drawRRect |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addRRect(const SkRRect& rrect, Direction dir, unsigned start) |
| |
| Add rrect to Path, creating a new closed Contour. If dir is kCW_Direction, rrect |
| winds clockwise; if dir is kCCW_Direction, rrect winds counterclockwise. |
| start determines the first point of rrect to add. |
| |
| #Table |
| #Legend |
| # start # location ## |
| #Legend ## |
| # 0 # right of top-left corner ## |
| # 1 # left of top-right corner ## |
| # 2 # bottom of top-right corner ## |
| # 3 # top of bottom-right corner ## |
| # 4 # left of bottom-right corner ## |
| # 5 # right of bottom-left corner ## |
| # 6 # top of bottom-left corner ## |
| # 7 # bottom of top-left corner ## |
| #Table ## |
| |
| After appending, Path may be empty, or may contain: Rect, Oval, or Round_Rect. |
| |
| #Param rrect bounds and radii of rounded rectangle ## |
| #Param dir Direction to wind Round_Rect ## |
| #Param start index of initial point of Round_Rect ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| SkRRect rrect; |
| rrect.setRectXY({40, 40, 215, 215}, 50, 50); |
| SkPath path; |
| path.addRRect(rrect); |
| canvas->drawPath(path, paint); |
| for (int start = 0; start < 8; ++start) { |
| SkPath textPath; |
| textPath.addRRect(rrect, SkPath::kCW_Direction, start); |
| canvas->drawTextOnPathHV(&"01234567"[start], 1, textPath, 0, -5, paint); |
| } |
| } |
| ## |
| |
| #SeeAlso addRoundRect SkCanvas::drawRRect |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addPoly(const SkPoint pts[], int count, bool close) |
| #In Build |
| #Line # adds one Contour containing connected lines ## |
| Add Contour created from Line array, adding (count - 1) Line segments. |
| Contour added starts at pts[0], then adds a line for every additional Point |
| in pts array. If close is true,appends kClose_Verb to Path, connecting |
| pts[count - 1] and pts[0]. |
| |
| If count is zero, append kMove_Verb to path. |
| Has no effect if count is less than one. |
| |
| #Param pts array of Line sharing end and start Point ## |
| #Param count length of Point array ## |
| #Param close true to add Line connecting Contour end and start ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setStrokeWidth(15); |
| paint.setStrokeCap(SkPaint::kRound_Cap); |
| const SkPoint points[] = {{20, 20}, {70, 20}, {40, 90}}; |
| for (bool close : { false, true } ) { |
| SkPath path; |
| path.addPoly(points, SK_ARRAY_COUNT(points), close); |
| for (auto style : {SkPaint::kStroke_Style, SkPaint::kFill_Style, |
| SkPaint::kStrokeAndFill_Style} ) { |
| paint.setStyle(style); |
| canvas->drawPath(path, paint); |
| canvas->translate(85, 0); |
| } |
| canvas->translate(-255, 128); |
| } |
| } |
| ## |
| |
| #SeeAlso SkCanvas::drawPoints |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Enum AddPathMode |
| #Line # sets addPath options ## |
| |
| #Code |
| enum AddPathMode { |
| kAppend_AddPathMode, |
| kExtend_AddPathMode, |
| }; |
| ## |
| |
| AddPathMode chooses how addPath appends. Adding one Path to another can extend |
| the last Contour or start a new Contour. |
| |
| #Const kAppend_AddPathMode |
| #Line # appended to destination unaltered ## |
| Path Verbs, Points, and Conic_Weights are appended to destination unaltered. |
| Since Path Verb_Array begins with kMove_Verb if src is not empty, this |
| starts a new Contour. |
| ## |
| #Const kExtend_AddPathMode |
| #Line # add line if prior Contour is not closed ## |
| If destination is closed or empty, start a new Contour. If destination |
| is not empty, add Line from Last_Point to added Path first Point. Skip added |
| Path initial kMove_Verb, then append remining Verbs, Points, and Conic_Weights. |
| ## |
| |
| #Example |
| #Description |
| test is built from path, open on the top row, and closed on the bottom row. |
| The left column uses kAppend_AddPathMode; the right uses kExtend_AddPathMode. |
| The top right composition is made up of one contour; the other three have two. |
| ## |
| #Height 180 |
| SkPath path, path2; |
| path.moveTo(20, 20); |
| path.lineTo(20, 40); |
| path.lineTo(40, 20); |
| path2.moveTo(60, 60); |
| path2.lineTo(80, 60); |
| path2.lineTo(80, 40); |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| for (int i = 0; i < 2; i++) { |
| for (auto addPathMode : { SkPath::kAppend_AddPathMode, SkPath::kExtend_AddPathMode } ) { |
| SkPath test(path); |
| test.addPath(path2, addPathMode); |
| canvas->drawPath(test, paint); |
| canvas->translate(100, 0); |
| } |
| canvas->translate(-200, 100); |
| path.close(); |
| } |
| ## |
| |
| #SeeAlso addPath reverseAddPath |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addPath(const SkPath& src, SkScalar dx, SkScalar dy, |
| AddPathMode mode = kAppend_AddPathMode) |
| #In Build |
| #Line # adds contents of Path ## |
| |
| Append src to Path, offset by (dx, dy). |
| |
| If mode is kAppend_AddPathMode, src Verb_Array, Point_Array, and Conic_Weights are |
| added unaltered. If mode is kExtend_AddPathMode, add Line before appending |
| Verbs, Points, and Conic_Weights. |
| |
| #Param src Path Verbs, Points, and Conic_Weights to add ## |
| #Param dx offset added to src Point_Array x-axis coordinates ## |
| #Param dy offset added to src Point_Array y-axis coordinates ## |
| #Param mode kAppend_AddPathMode or kExtend_AddPathMode ## |
| |
| #Example |
| #Height 180 |
| SkPaint paint; |
| paint.setTextSize(128); |
| paint.setFakeBoldText(true); |
| SkPath dest, text; |
| paint.getTextPath("O", 1, 50, 120, &text); |
| for (int i = 0; i < 3; i++) { |
| dest.addPath(text, i * 20, i * 20); |
| } |
| Simplify(dest, &dest); |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setStrokeWidth(3); |
| canvas->drawPath(dest, paint); |
| ## |
| |
| #SeeAlso AddPathMode offset reverseAddPath |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addPath(const SkPath& src, AddPathMode mode = kAppend_AddPathMode) |
| |
| Append src to Path. |
| |
| If mode is kAppend_AddPathMode, src Verb_Array, Point_Array, and Conic_Weights are |
| added unaltered. If mode is kExtend_AddPathMode, add Line before appending |
| Verbs, Points, and Conic_Weights. |
| |
| #Param src Path Verbs, Points, and Conic_Weights to add ## |
| #Param mode kAppend_AddPathMode or kExtend_AddPathMode ## |
| |
| #Example |
| #Height 80 |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPath dest, path; |
| path.addOval({-80, 20, 0, 60}, SkPath::kCW_Direction, 1); |
| for (int i = 0; i < 2; i++) { |
| dest.addPath(path, SkPath::kExtend_AddPathMode); |
| dest.offset(100, 0); |
| } |
| canvas->drawPath(dest, paint); |
| ## |
| |
| #SeeAlso AddPathMode reverseAddPath |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void addPath(const SkPath& src, const SkMatrix& matrix, AddPathMode mode = kAppend_AddPathMode) |
| |
| Append src to Path, transformed by matrix. Transformed curves may have different |
| Verbs, Points, and Conic_Weights. |
| |
| If mode is kAppend_AddPathMode, src Verb_Array, Point_Array, and Conic_Weights are |
| added unaltered. If mode is kExtend_AddPathMode, add Line before appending |
| Verbs, Points, and Conic_Weights. |
| |
| #Param src Path Verbs, Points, and Conic_Weights to add ## |
| #Param matrix transform applied to src ## |
| #Param mode kAppend_AddPathMode or kExtend_AddPathMode ## |
| |
| #Example |
| #Height 160 |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| SkPath dest, path; |
| path.addOval({20, 20, 200, 120}, SkPath::kCW_Direction, 1); |
| for (int i = 0; i < 6; i++) { |
| SkMatrix matrix; |
| matrix.reset(); |
| matrix.setPerspX(i / 400.f); |
| dest.addPath(path, matrix); |
| } |
| canvas->drawPath(dest, paint); |
| ## |
| |
| #SeeAlso AddPathMode transform offset reverseAddPath |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void reverseAddPath(const SkPath& src) |
| #In Build |
| #Line # adds contents of Path back to front ## |
| Append src to Path, from back to front. |
| Reversed src always appends a new Contour to Path. |
| |
| #Param src Path Verbs, Points, and Conic_Weights to add ## |
| |
| #Example |
| #Height 200 |
| SkPath path; |
| path.moveTo(20, 20); |
| path.lineTo(20, 40); |
| path.lineTo(40, 20); |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| for (int i = 0; i < 2; i++) { |
| SkPath path2; |
| path2.moveTo(60, 60); |
| path2.lineTo(80, 60); |
| path2.lineTo(80, 40); |
| for (int j = 0; j < 2; j++) { |
| SkPath test(path); |
| test.reverseAddPath(path2); |
| canvas->drawPath(test, paint); |
| canvas->translate(100, 0); |
| path2.close(); |
| } |
| canvas->translate(-200, 100); |
| path.close(); |
| } |
| ## |
| |
| #SeeAlso AddPathMode transform offset addPath |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void offset(SkScalar dx, SkScalar dy, SkPath* dst) const |
| #In Transform |
| #Line # translates Point_Array ## |
| Offset Point_Array by (dx, dy). Offset Path replaces dst. |
| If dst is nullptr, Path is replaced by offset data. |
| |
| #Param dx offset added to Point_Array x-axis coordinates ## |
| #Param dy offset added to Point_Array y-axis coordinates ## |
| #Param dst overwritten, translated copy of Path; may be nullptr ## |
| |
| #Example |
| #Height 60 |
| SkPath pattern; |
| pattern.moveTo(20, 20); |
| pattern.lineTo(20, 40); |
| pattern.lineTo(40, 20); |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| for (int i = 0; i < 10; i++) { |
| SkPath path; |
| pattern.offset(20 * i, 0, &path); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso addPath transform |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Transform |
| #Populate |
| #Line # modify all points ## |
| ## |
| |
| #Method void offset(SkScalar dx, SkScalar dy) |
| #In Transform |
| Offset Point_Array by (dx, dy). Path is replaced by offset data. |
| |
| #Param dx offset added to Point_Array x-axis coordinates ## |
| #Param dy offset added to Point_Array y-axis coordinates ## |
| |
| #Example |
| #Height 60 |
| SkPath path; |
| path.moveTo(20, 20); |
| path.lineTo(20, 40); |
| path.lineTo(40, 20); |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| for (int i = 0; i < 10; i++) { |
| canvas->drawPath(path, paint); |
| path.offset(20, 0); |
| } |
| ## |
| |
| #SeeAlso addPath transform SkCanvas::translate() |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void transform(const SkMatrix& matrix, SkPath* dst) const |
| #In Transform |
| #Line # applies Matrix to Point_Array and Weights ## |
| Transform Verb_Array, Point_Array, and weight by matrix. |
| transform may change Verbs and increase their number. |
| Transformed Path replaces dst; if dst is nullptr, original data |
| is replaced. |
| |
| #Param matrix Matrix to apply to Path ## |
| #Param dst overwritten, transformed copy of Path; may be nullptr ## |
| |
| #Example |
| #Height 200 |
| SkPath pattern; |
| pattern.moveTo(100, 100); |
| pattern.lineTo(100, 20); |
| pattern.lineTo(20, 100); |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| for (int i = 0; i < 10; i++) { |
| SkPath path; |
| SkMatrix matrix; |
| matrix.setRotate(36 * i, 100, 100); |
| pattern.transform(matrix, &path); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso addPath offset SkCanvas::concat() SkMatrix |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void transform(const SkMatrix& matrix) |
| |
| Transform Verb_Array, Point_Array, and weight by matrix. |
| transform may change Verbs and increase their number. |
| Path is replaced by transformed data. |
| |
| #Param matrix Matrix to apply to Path ## |
| |
| #Example |
| #Height 200 |
| SkPath path; |
| path.moveTo(100, 100); |
| path.quadTo(100, 20, 20, 100); |
| SkPaint paint; |
| paint.setStyle(SkPaint::kStroke_Style); |
| for (int i = 0; i < 10; i++) { |
| SkMatrix matrix; |
| matrix.setRotate(36, 100, 100); |
| path.transform(matrix); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso addPath offset SkCanvas::concat() SkMatrix |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Subtopic Last_Point |
| #Line # final Point in Contour ## |
| |
| Path is defined cumulatively, often by adding a segment to the end of last |
| Contour. Last_Point of Contour is shared as first Point of added Line or Curve. |
| Last_Point can be read and written directly with getLastPt and setLastPt. |
| |
| #Method bool getLastPt(SkPoint* lastPt) const |
| #In Property |
| #In Last_Point |
| #Line # returns Last_Point ## |
| Returns Last_Point on Path in lastPt. Returns false if Point_Array is empty, |
| storing (0, 0) if lastPt is not nullptr. |
| |
| #Param lastPt storage for final Point in Point_Array; may be nullptr ## |
| |
| #Return true if Point_Array contains one or more Points ## |
| |
| #Example |
| SkPath path; |
| path.moveTo(100, 100); |
| path.quadTo(100, 20, 20, 100); |
| SkMatrix matrix; |
| matrix.setRotate(36, 100, 100); |
| path.transform(matrix); |
| SkPoint last; |
| path.getLastPt(&last); |
| SkDebugf("last point: %g, %g\n", last.fX, last.fY); |
| #StdOut |
| last point: 35.2786, 52.9772 |
| ## |
| ## |
| |
| #SeeAlso setLastPt |
| |
| ## |
| |
| #Method void setLastPt(SkScalar x, SkScalar y) |
| #In Utility |
| #In Last_Point |
| #Line # replaces Last_Point ## |
| Set Last_Point to (x, y). If Point_Array is empty, append kMove_Verb to |
| Verb_Array and append (x, y) to Point_Array. |
| |
| #Param x set x-axis value of Last_Point ## |
| #Param y set y-axis value of Last_Point ## |
| |
| #Example |
| #Height 128 |
| SkPaint paint; |
| paint.setTextSize(128); |
| SkPath path; |
| paint.getTextPath("@", 1, 60, 100, &path); |
| path.setLastPt(20, 120); |
| canvas->drawPath(path, paint); |
| ## |
| |
| #SeeAlso getLastPt |
| |
| ## |
| |
| #Method void setLastPt(const SkPoint& p) |
| |
| Set the last point on the path. If Point_Array is empty, append kMove_Verb to |
| Verb_Array and append p to Point_Array. |
| |
| #Param p set value of Last_Point ## |
| |
| #Example |
| #Height 128 |
| SkPaint paint; |
| paint.setTextSize(128); |
| SkPath path, path2; |
| paint.getTextPath("A", 1, 60, 100, &path); |
| paint.getTextPath("Z", 1, 60, 100, &path2); |
| SkPoint pt, pt2; |
| path.getLastPt(&pt); |
| path2.getLastPt(&pt2); |
| path.setLastPt(pt2); |
| path2.setLastPt(pt); |
| canvas->drawPath(path, paint); |
| canvas->drawPath(path2, paint); |
| ## |
| |
| #SeeAlso getLastPt |
| |
| ## |
| |
| #Subtopic Last_Point ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Enum SegmentMask |
| #Line # returns Verb types in Path ## |
| |
| #Code |
| enum SegmentMask { |
| kLine_SegmentMask = 1 << 0, |
| kQuad_SegmentMask = 1 << 1, |
| kConic_SegmentMask = 1 << 2, |
| kCubic_SegmentMask = 1 << 3, |
| }; |
| ## |
| |
| SegmentMask constants correspond to each drawing Verb type in Path; for |
| instance, if Path only contains Lines, only the kLine_SegmentMask bit is set. |
| |
| #Bug 6785 |
| #Const kLine_SegmentMask 1 |
| #Line # contains one or more Lines ## |
| Set if Verb_Array contains kLine_Verb. |
| ## |
| #Const kQuad_SegmentMask 2 |
| #Line # contains one or more Quads ## |
| Set if Verb_Array contains kQuad_Verb. Note that conicTo may add a Quad. |
| ## |
| #Const kConic_SegmentMask 4 |
| #Line # contains one or more Conics ## |
| Set if Verb_Array contains kConic_Verb. |
| ## |
| #Const kCubic_SegmentMask 8 |
| #Line # contains one or more Cubics ## |
| Set if Verb_Array contains kCubic_Verb. |
| ## |
| |
| #Example |
| #Description |
| When conicTo has a weight of one, Quad is added to Path. |
| ## |
| SkPath path; |
| path.conicTo(10, 10, 20, 30, 1); |
| SkDebugf("Path kConic_SegmentMask is %s\n", path.getSegmentMasks() & |
| SkPath::kConic_SegmentMask ? "set" : "clear"); |
| SkDebugf("Path kQuad_SegmentMask is %s\n", path.getSegmentMasks() & |
| SkPath::kQuad_SegmentMask ? "set" : "clear"); |
| #StdOut |
| Path kConic_SegmentMask is clear |
| Path kQuad_SegmentMask is set |
| ## |
| ## |
| |
| #SeeAlso getSegmentMasks Verb |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method uint32_t getSegmentMasks() const |
| #In Utility |
| #In Property |
| #Line # returns types in Verb_Array ## |
| Returns a mask, where each set bit corresponds to a SegmentMask constant |
| if Path contains one or more Verbs of that type. |
| Returns zero if Path contains no Lines, or Curves: Quads, Conics, or Cubics. |
| |
| getSegmentMasks() returns a cached result; it is very fast. |
| |
| #Return SegmentMask bits or zero ## |
| |
| #Example |
| SkPath path; |
| path.quadTo(20, 30, 40, 50); |
| path.close(); |
| const char* masks[] = { "line", "quad", "conic", "cubic" }; |
| int index = 0; |
| for (auto mask : { SkPath::kLine_SegmentMask, SkPath::kQuad_SegmentMask, |
| SkPath::kConic_SegmentMask, SkPath::kCubic_SegmentMask } ) { |
| if (mask & path.getSegmentMasks()) { |
| SkDebugf("mask %s set\n", masks[index]); |
| } |
| ++index; |
| } |
| #StdOut |
| mask quad set |
| ## |
| ## |
| |
| #SeeAlso getSegmentMasks Verb |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool contains(SkScalar x, SkScalar y) const |
| #In Property |
| #Line # returns if Point is in fill area ## |
| Returns true if the point (x, y) is contained by Path, taking into |
| account FillType. |
| |
| #Table |
| #Legend |
| # FillType # contains() returns true if Point is enclosed by ## |
| ## |
| # kWinding_FillType # a non-zero sum of Contour Directions. ## |
| # kEvenOdd_FillType # an odd number of Contours. ## |
| # kInverseWinding_FillType # a zero sum of Contour Directions. ## |
| # kInverseEvenOdd_FillType # and even number of Contours. ## |
| ## |
| |
| #Param x x-axis value of containment test ## |
| #Param y y-axis value of containment test ## |
| |
| #Return true if Point is in Path ## |
| |
| #Example |
| SkPath path; |
| SkPaint paint; |
| paint.setTextSize(256); |
| paint.getTextPath("&", 1, 30, 220, &path); |
| for (int y = 2; y < 256; y += 9) { |
| for (int x = 2; x < 256; x += 9) { |
| int coverage = 0; |
| for (int iy = -4; iy <= 4; iy += 2) { |
| for (int ix = -4; ix <= 4; ix += 2) { |
| coverage += path.contains(x + ix, y + iy); |
| } |
| } |
| paint.setColor(SkColorSetARGB(0x5f, 0xff * coverage / 25, 0, 0xff * (25 - coverage) / 25)); |
| canvas->drawCircle(x, y, 8, paint); |
| } |
| } |
| ## |
| |
| #SeeAlso conservativelyContainsRect Fill_Type Op |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void dump(SkWStream* stream, bool forceClose, bool dumpAsHex) const |
| #In Utility |
| #Line # sends text representation using floats to standard output ## |
| Writes text representation of Path to stream. If stream is nullptr, writes to |
| standard output. Set forceClose to true to get edges used to fill Path. |
| Set dumpAsHex true to generate exact binary representations |
| of floating point numbers used in Point_Array and Conic_Weights. |
| |
| #Param stream writable Stream receiving Path text representation; may be nullptr ## |
| #Param forceClose true if missing kClose_Verb is output ## |
| #Param dumpAsHex true if SkScalar values are written as hexadecimal ## |
| |
| #Example |
| SkPath path; |
| path.quadTo(20, 30, 40, 50); |
| for (bool forceClose : { false, true } ) { |
| for (bool dumpAsHex : { false, true } ) { |
| path.dump(nullptr, forceClose, dumpAsHex); |
| SkDebugf("\n"); |
| } |
| } |
| #StdOut |
| path.setFillType(SkPath::kWinding_FillType); |
| path.moveTo(0, 0); |
| path.quadTo(20, 30, 40, 50); |
| |
| path.setFillType(SkPath::kWinding_FillType); |
| path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0 |
| path.quadTo(SkBits2Float(0x41a00000), SkBits2Float(0x41f00000), SkBits2Float(0x42200000), SkBits2Float(0x42480000)); // 20, 30, 40, 50 |
| |
| path.setFillType(SkPath::kWinding_FillType); |
| path.moveTo(0, 0); |
| path.quadTo(20, 30, 40, 50); |
| path.lineTo(0, 0); |
| path.close(); |
| |
| path.setFillType(SkPath::kWinding_FillType); |
| path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0 |
| path.quadTo(SkBits2Float(0x41a00000), SkBits2Float(0x41f00000), SkBits2Float(0x42200000), SkBits2Float(0x42480000)); // 20, 30, 40, 50 |
| path.lineTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0 |
| path.close(); |
| ## |
| ## |
| |
| #SeeAlso SkRect::dump() SkRRect::dump() SkPathMeasure::dump() |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void dump() const |
| |
| Writes text representation of Path to standard output. The representation may be |
| directly compiled as C++ code. Floating point values are written |
| with limited precision; it may not be possible to reconstruct original Path |
| from output. |
| |
| #Example |
| SkPath path, copy; |
| path.lineTo(6.f / 7, 2.f / 3); |
| path.dump(); |
| copy.setFillType(SkPath::kWinding_FillType); |
| copy.moveTo(0, 0); |
| copy.lineTo(0.857143f, 0.666667f); |
| SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not "); |
| #StdOut |
| path.setFillType(SkPath::kWinding_FillType); |
| path.moveTo(0, 0); |
| path.lineTo(0.857143f, 0.666667f); |
| path is not equal to copy |
| ## |
| ## |
| |
| #SeeAlso dumpHex SkRect::dump() SkRRect::dump() SkPathMeasure::dump() writeToMemory |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void dumpHex() const |
| #In Utility |
| #Line # sends text representation using hexadecimal to standard output ## |
| Writes text representation of Path to standard output. The representation may be |
| directly compiled as C++ code. Floating point values are written |
| in hexadecimal to preserve their exact bit pattern. The output reconstructs the |
| original Path. |
| |
| Use instead of dump() when submitting |
| #A bug reports against Skia # https://bug.skia.org ## |
| . |
| |
| #Example |
| SkPath path, copy; |
| path.lineTo(6.f / 7, 2.f / 3); |
| path.dumpHex(); |
| copy.setFillType(SkPath::kWinding_FillType); |
| copy.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0 |
| copy.lineTo(SkBits2Float(0x3f5b6db7), SkBits2Float(0x3f2aaaab)); // 0.857143f, 0.666667f |
| SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not "); |
| #StdOut |
| path.setFillType(SkPath::kWinding_FillType); |
| path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0 |
| path.lineTo(SkBits2Float(0x3f5b6db7), SkBits2Float(0x3f2aaaab)); // 0.857143f, 0.666667f |
| path is equal to copy |
| ## |
| ## |
| |
| #SeeAlso dump SkRect::dumpHex SkRRect::dumpHex writeToMemory |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method size_t writeToMemory(void* buffer) const |
| #In Utility |
| #Line # copies data to buffer ## |
| Writes Path to buffer, returning the number of bytes written. |
| Pass nullptr to obtain the storage size. |
| |
| Writes Fill_Type, Verb_Array, Point_Array, Conic_Weight, and |
| additionally writes computed information like Convexity and bounds. |
| |
| Use only be used in concert with readFromMemory; |
| the format used for Path in memory is not guaranteed. |
| |
| #Param buffer storage for Path; may be nullptr ## |
| |
| #Return size of storage required for Path; always a multiple of 4 ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPath path, copy; |
| path.lineTo(6.f / 7, 2.f / 3); |
| size_t size = path.writeToMemory(nullptr); |
| SkTDArray<char> storage; |
| storage.setCount(size); |
| path.writeToMemory(storage.begin()); |
| copy.readFromMemory(storage.begin(), size); |
| SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not "); |
| } |
| #StdOut |
| path is equal to copy |
| ## |
| ## |
| |
| #SeeAlso serialize readFromMemory dump dumpHex |
| |
| ## |
| |
| #Method sk_sp<SkData> serialize() const |
| #In Utility |
| #Line # copies data to buffer ## |
| Write Path to buffer, returning the buffer written to, wrapped in Data. |
| |
| serialize() writes Fill_Type, Verb_Array, Point_Array, Conic_Weight, and |
| additionally writes computed information like Convexity and bounds. |
| |
| serialize() should only be used in concert with readFromMemory. |
| The format used for Path in memory is not guaranteed. |
| |
| #Return Path data wrapped in Data buffer ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPath path, copy; |
| path.lineTo(6.f / 7, 2.f / 3); |
| sk_sp<SkData> data = path.serialize(); |
| copy.readFromMemory(data->data(), data->size()); |
| SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not "); |
| } |
| #StdOut |
| path is equal to copy |
| ## |
| ## |
| |
| #SeeAlso writeToMemory readFromMemory dump dumpHex |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method size_t readFromMemory(const void* buffer, size_t length) |
| #In Utility |
| #Line # initializes from buffer ## |
| Initializes Path from buffer of size length. Returns zero if the buffer is |
| data is inconsistent, or the length is too small. |
| |
| Reads Fill_Type, Verb_Array, Point_Array, Conic_Weight, and |
| additionally reads computed information like Convexity and bounds. |
| |
| Used only in concert with writeToMemory; |
| the format used for Path in memory is not guaranteed. |
| |
| #Param buffer storage for Path ## |
| #Param length buffer size in bytes; must be multiple of 4 ## |
| |
| #Return number of bytes read, or zero on failure ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPath path, copy; |
| path.lineTo(6.f / 7, 2.f / 3); |
| size_t size = path.writeToMemory(nullptr); |
| SkTDArray<char> storage; |
| storage.setCount(size); |
| path.writeToMemory(storage.begin()); |
| size_t wrongSize = size - 4; |
| size_t bytesRead = copy.readFromMemory(storage.begin(), wrongSize); |
| SkDebugf("length = %u; returned by readFromMemory = %u\n", wrongSize, bytesRead); |
| size_t largerSize = size + 4; |
| bytesRead = copy.readFromMemory(storage.begin(), largerSize); |
| SkDebugf("length = %u; returned by readFromMemory = %u\n", largerSize, bytesRead); |
| } |
| #StdOut |
| length = 32; returned by readFromMemory = 0 |
| length = 40; returned by readFromMemory = 36 |
| ## |
| ## |
| |
| #SeeAlso writeToMemory |
| |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Generation_ID |
| #Alias Generation_IDs ## |
| #Line # value reflecting contents change ## |
| Generation_ID provides a quick way to check if Verb_Array, Point_Array, or |
| Conic_Weight has changed. Generation_ID is not a hash; identical Paths will |
| not necessarily have matching Generation_IDs. |
| |
| Empty Paths have a Generation_ID of one. |
| |
| #Method uint32_t getGenerationID() const |
| |
| #In Generation_ID |
| #Line # returns unique ID ## |
| Returns a non-zero, globally unique value. A different value is returned |
| if Verb_Array, Point_Array, or Conic_Weight changes. |
| |
| Setting Fill_Type does not change Generation_ID. |
| |
| Each time the path is modified, a different Generation_ID will be returned. |
| |
| #Bug 1762 |
| Fill_Type does affect Generation_ID on Android framework. |
| |
| #Return non-zero, globally unique value ## |
| |
| #Example |
| SkPath path; |
| SkDebugf("empty genID = %u\n", path.getGenerationID()); |
| path.lineTo(1, 2); |
| SkDebugf("1st lineTo genID = %u\n", path.getGenerationID()); |
| path.rewind(); |
| SkDebugf("empty genID = %u\n", path.getGenerationID()); |
| path.lineTo(1, 2); |
| SkDebugf("2nd lineTo genID = %u\n", path.getGenerationID()); |
| #StdOut |
| empty genID = 1 |
| 1st lineTo genID = 2 |
| empty genID = 1 |
| 2nd lineTo genID = 3 |
| ## |
| ## |
| |
| #SeeAlso operator==(const SkPath& a, const SkPath& b) |
| |
| ## |
| |
| #Subtopic ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isValid() const |
| #In Property |
| #In Utility |
| #Line # returns if data is internally consistent ## |
| Returns if Path data is consistent. Corrupt Path data is detected if |
| internal values are out of range or internal storage does not match |
| array dimensions. |
| |
| #Return true if Path data is consistent ## |
| |
| #NoExample |
| ## |
| |
| ## |
| |
| #Method bool pathRefIsValid() const |
| #Deprecated soon |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Class Iter |
| #Line # data iterator ## |
| |
| #Code |
| class Iter { |
| public: |
| Iter(); |
| Iter(const SkPath& path, bool forceClose); |
| void setPath(const SkPath& path, bool forceClose); |
| Verb next(SkPoint pts[4], bool doConsumeDegenerates = true, bool exact = false); |
| SkScalar conicWeight() const; |
| bool isCloseLine() const; |
| bool isClosedContour() const; |
| }; |
| ## |
| |
| Iterates through Verb_Array, and associated Point_Array and Conic_Weight. |
| Provides options to treat open Contours as closed, and to ignore |
| degenerate data. |
| |
| #Example |
| #Height 128 |
| #Description |
| Ignoring the actual Verbs and replacing them with Quads rounds the |
| path of the glyph. |
| ## |
| void draw(SkCanvas* canvas) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setTextSize(256); |
| SkPath asterisk, path; |
| paint.getTextPath("*", 1, 50, 192, &asterisk); |
| SkPath::Iter iter(asterisk, true); |
| SkPoint start[4], pts[4]; |
| iter.next(start); // skip moveTo |
| iter.next(start); // first quadTo |
| path.moveTo((start[0] + start[1]) * 0.5f); |
| while (SkPath::kClose_Verb != iter.next(pts)) { |
| path.quadTo(pts[0], (pts[0] + pts[1]) * 0.5f); |
| } |
| path.quadTo(start[0], (start[0] + start[1]) * 0.5f); |
| canvas->drawPath(path, paint); |
| } |
| ## |
| |
| #SeeAlso RawIter |
| |
| #Method Iter() |
| #Line # constructs Path iterator ## |
| Initializes Iter with an empty Path. next() on Iter returns kDone_Verb. |
| Call setPath to initialize Iter at a later time. |
| |
| #Return Iter of empty Path ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPath::Iter iter; |
| SkPoint points[4]; |
| SkDebugf("iter is " "%s" "done\n", SkPath::kDone_Verb == iter.next(points) ? "" : "not "); |
| SkPath path; |
| iter.setPath(path, false); |
| SkDebugf("iter is " "%s" "done\n", SkPath::kDone_Verb == iter.next(points) ? "" : "not "); |
| } |
| #StdOut |
| iter is done |
| iter is done |
| ## |
| ## |
| |
| #SeeAlso setPath |
| |
| ## |
| |
| #Method Iter(const SkPath& path, bool forceClose) |
| |
| Sets Iter to return elements of Verb_Array, Point_Array, and Conic_Weight in path. |
| If forceClose is true, Iter will add kLine_Verb and kClose_Verb after each |
| open Contour. path is not altered. |
| |
| #Param path Path to iterate ## |
| #Param forceClose true if open Contours generate kClose_Verb ## |
| |
| #Return Iter of path ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, SkPath::Iter& iter) -> void { |
| SkDebugf("%s:\n", prefix); |
| const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" }; |
| const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 }; |
| SkPath::Verb verb; |
| do { |
| SkPoint points[4]; |
| verb = iter.next(points); |
| SkDebugf("k%s_Verb ", verbStr[(int) verb]); |
| for (int i = 0; i < pointCount[(int) verb]; ++i) { |
| SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY); |
| } |
| if (SkPath::kConic_Verb == verb) { |
| SkDebugf("weight = %g", iter.conicWeight()); |
| } |
| SkDebugf("\n"); |
| } while (SkPath::kDone_Verb != verb); |
| SkDebugf("\n"); |
| }; |
| |
| SkPath path; |
| path.quadTo(10, 20, 30, 40); |
| SkPath::Iter openIter(path, false); |
| debugster("open", openIter); |
| SkPath::Iter closedIter(path, true); |
| debugster("closed", closedIter); |
| } |
| #StdOut |
| open: |
| kMove_Verb {0, 0}, |
| kQuad_Verb {0, 0}, {10, 20}, {30, 40}, |
| kDone_Verb |
| |
| closed: |
| kMove_Verb {0, 0}, |
| kQuad_Verb {0, 0}, {10, 20}, {30, 40}, |
| kLine_Verb {30, 40}, {0, 0}, |
| kClose_Verb {0, 0}, |
| kDone_Verb |
| ## |
| ## |
| |
| #SeeAlso setPath |
| |
| ## |
| |
| #Method void setPath(const SkPath& path, bool forceClose) |
| |
| Sets Iter to return elements of Verb_Array, Point_Array, and Conic_Weight in path. |
| If forceClose is true, Iter will add kLine_Verb and kClose_Verb after each |
| open Contour. path is not altered. |
| |
| #Param path Path to iterate ## |
| #Param forceClose true if open Contours generate kClose_Verb ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, SkPath::Iter& iter) -> void { |
| SkDebugf("%s:\n", prefix); |
| const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" }; |
| const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 }; |
| SkPath::Verb verb; |
| do { |
| SkPoint points[4]; |
| verb = iter.next(points); |
| SkDebugf("k%s_Verb ", verbStr[(int) verb]); |
| for (int i = 0; i < pointCount[(int) verb]; ++i) { |
| SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY); |
| } |
| if (SkPath::kConic_Verb == verb) { |
| SkDebugf("weight = %g", iter.conicWeight()); |
| } |
| SkDebugf("\n"); |
| } while (SkPath::kDone_Verb != verb); |
| SkDebugf("\n"); |
| }; |
| |
| SkPath path; |
| path.quadTo(10, 20, 30, 40); |
| SkPath::Iter iter(path, false); |
| debugster("quad open", iter); |
| SkPath path2; |
| path2.conicTo(1, 2, 3, 4, .5f); |
| iter.setPath(path2, true); |
| debugster("conic closed", iter); |
| } |
| #StdOut |
| quad open: |
| kMove_Verb {0, 0}, |
| kQuad_Verb {0, 0}, {10, 20}, {30, 40}, |
| kDone_Verb |
| |
| conic closed: |
| kMove_Verb {0, 0}, |
| kConic_Verb {0, 0}, {1, 2}, {3, 4}, weight = 0.5 |
| kLine_Verb {3, 4}, {0, 0}, |
| kClose_Verb {0, 0}, |
| kDone_Verb |
| ## |
| ## |
| |
| #SeeAlso Iter(const SkPath& path, bool forceClose) |
| |
| ## |
| |
| #Method Verb next(SkPoint pts[4], bool doConsumeDegenerates = true, bool exact = false) |
| |
| Returns next Verb in Verb_Array, and advances Iter. |
| When Verb_Array is exhausted, returns kDone_Verb. |
| |
| Zero to four Points are stored in pts, depending on the returned Verb. |
| |
| If doConsumeDegenerates is true, skip consecutive kMove_Verb entries, returning |
| only the last in the series; and skip very small Lines, Quads, and Conics; and |
| skip kClose_Verb following kMove_Verb. |
| if doConsumeDegenerates is true and exact is true, only skip Lines, Quads, and |
| Conics with zero lengths. |
| |
| #Param pts storage for Point data describing returned Verb ## |
| #Param doConsumeDegenerates if true, skip degenerate Verbs ## |
| #Param exact skip zero length curves ## |
| |
| #Return next Verb from Verb_Array ## |
| |
| #Example |
| #Description |
| skip degenerate skips the first in a kMove_Verb pair, the kMove_Verb |
| followed by the kClose_Verb, the zero length Line and the very small Line. |
| |
| skip degenerate if exact skips the same as skip degenerate, but shows |
| the very small Line. |
| |
| skip none shows all of the Verbs and Points in Path. |
| ## |
| void draw(SkCanvas* canvas) { |
| auto debugster = [](const char* prefix, const SkPath& path, bool degen, bool exact) -> void { |
| SkPath::Iter iter(path, false); |
| SkDebugf("%s:\n", prefix); |
| const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" }; |
| const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 }; |
| SkPath::Verb verb; |
| do { |
| SkPoint points[4]; |
| verb = iter.next(points, degen, exact); |
| SkDebugf("k%s_Verb ", verbStr[(int) verb]); |
| for (int i = 0; i < pointCount[(int) verb]; ++i) { |
| SkDebugf("{%1.8g, %1.8g}, ", points[i].fX, points[i].fY); |
| } |
| SkDebugf("\n"); |
| } while (SkPath::kDone_Verb != verb); |
| SkDebugf("\n"); |
| }; |
| |
| SkPath path; |
| path.moveTo(10, 10); |
| path.moveTo(20, 20); |
| path.quadTo(10, 20, 30, 40); |
| path.moveTo(1, 1); |
| path.close(); |
| path.moveTo(30, 30); |
| path.lineTo(30, 30); |
| path.moveTo(30, 30); |
| path.lineTo(30.00001f, 30); |
| debugster("skip degenerate", path, true, false); |
| debugster("skip degenerate if exact", path, true, true); |
| debugster("skip none", path, false, false); |
| } |
| #StdOut |
| skip degenerate: |
| kMove_Verb {20, 20}, |
| kQuad_Verb {20, 20}, {10, 20}, {30, 40}, |
| kDone_Verb |
| |
| skip degenerate if exact: |
| kMove_Verb {20, 20}, |
| kQuad_Verb {20, 20}, {10, 20}, {30, 40}, |
| kMove_Verb {30, 30}, |
| kLine_Verb {30, 30}, {30.00001, 30}, |
| kDone_Verb |
| |
| skip none: |
| kMove_Verb {10, 10}, |
| kMove_Verb {20, 20}, |
| kQuad_Verb {20, 20}, {10, 20}, {30, 40}, |
| kMove_Verb {1, 1}, |
| kClose_Verb {1, 1}, |
| kMove_Verb {30, 30}, |
| kLine_Verb {30, 30}, {30, 30}, |
| kMove_Verb {30, 30}, |
| kLine_Verb {30, 30}, {30.00001, 30}, |
| kDone_Verb |
| ## |
| ## |
| |
| #SeeAlso Verb IsLineDegenerate IsCubicDegenerate IsQuadDegenerate |
| |
| ## |
| |
| #Method SkScalar conicWeight() const |
| |
| Returns Conic_Weight if next() returned kConic_Verb. |
| |
| If next() has not been called, or next() did not return kConic_Verb, |
| result is undefined. |
| |
| #Return Conic_Weight for Conic Points returned by next() ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPath path; |
| path.conicTo(1, 2, 3, 4, .5f); |
| SkPath::Iter iter(path, false); |
| SkPoint p[4]; |
| SkDebugf("first verb is " "%s" "move\n", SkPath::kMove_Verb == iter.next(p) ? "" : "not "); |
| SkDebugf("next verb is " "%s" "conic\n", SkPath::kConic_Verb == iter.next(p) ? "" : "not "); |
| SkDebugf("conic points: {%g,%g}, {%g,%g}, {%g,%g}\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY, |
| p[2].fX, p[2].fY); |
| SkDebugf("conic weight: %g\n", iter.conicWeight()); |
| } |
| #StdOut |
| first verb is move |
| next verb is conic |
| conic points: {0,0}, {1,2}, {3,4} |
| conic weight: 0.5 |
| ## |
| ## |
| |
| #SeeAlso Conic_Weight |
| |
| ## |
| |
| #Method bool isCloseLine() const |
| #Line # returns if Line was generated by kClose_Verb ## |
| Returns true if last kLine_Verb returned by next() was generated |
| by kClose_Verb. When true, the end point returned by next() is |
| also the start point of Contour. |
| |
| If next() has not been called, or next() did not return kLine_Verb, |
| result is undefined. |
| |
| #Return true if last kLine_Verb was generated by kClose_Verb ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPath path; |
| path.moveTo(6, 7); |
| path.conicTo(1, 2, 3, 4, .5f); |
| path.close(); |
| SkPath::Iter iter(path, false); |
| SkPoint p[4]; |
| SkDebugf("1st verb is " "%s" "move\n", SkPath::kMove_Verb == iter.next(p) ? "" : "not "); |
| SkDebugf("moveTo point: {%g,%g}\n", p[0].fX, p[0].fY); |
| SkDebugf("2nd verb is " "%s" "conic\n", SkPath::kConic_Verb == iter.next(p) ? "" : "not "); |
| SkDebugf("3rd verb is " "%s" "line\n", SkPath::kLine_Verb == iter.next(p) ? "" : "not "); |
| SkDebugf("line points: {%g,%g}, {%g,%g}\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY); |
| SkDebugf("line " "%s" "generated by close\n", iter.isCloseLine() ? "" : "not "); |
| SkDebugf("4th verb is " "%s" "close\n", SkPath::kClose_Verb == iter.next(p) ? "" : "not "); |
| } |
| #StdOut |
| 1st verb is move |
| moveTo point: {6,7} |
| 2nd verb is conic |
| 3rd verb is line |
| line points: {3,4}, {6,7} |
| line generated by close |
| 4th verb is close |
| ## |
| ## |
| |
| #SeeAlso close() |
| ## |
| |
| #Method bool isClosedContour() const |
| #Line # returns if Contour has kClose_Verb ## |
| Returns true if subsequent calls to next() return kClose_Verb before returning |
| kMove_Verb. if true, Contour Iter is processing may end with kClose_Verb, or |
| Iter may have been initialized with force close set to true. |
| |
| #Return true if Contour is closed ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| for (bool forceClose : { false, true } ) { |
| SkPath path; |
| path.conicTo(1, 2, 3, 4, .5f); |
| SkPath::Iter iter(path, forceClose); |
| SkDebugf("without close(), forceClose is %s: isClosedContour returns %s\n", |
| forceClose ? "true " : "false", iter.isClosedContour() ? "true" : "false"); |
| path.close(); |
| iter.setPath(path, forceClose); |
| SkDebugf("with close(), forceClose is %s: isClosedContour returns %s\n", |
| forceClose ? "true " : "false", iter.isClosedContour() ? "true" : "false"); |
| } |
| } |
| #StdOut |
| without close(), forceClose is false: isClosedContour returns false |
| with close(), forceClose is false: isClosedContour returns true |
| without close(), forceClose is true : isClosedContour returns true |
| with close(), forceClose is true : isClosedContour returns true |
| ## |
| ## |
| |
| #SeeAlso Iter(const SkPath& path, bool forceClose) |
| |
| ## |
| |
| #Class Iter ## |
| |
| #Class RawIter |
| #Line # raw data iterator ## |
| |
| #Code |
| class RawIter { |
| public: |
| RawIter(); |
| RawIter(const SkPath& path); |
| void setPath(const SkPath& path); |
| Verb next(SkPoint pts[4]); |
| Verb peek() const; |
| SkScalar conicWeight() const; |
| } |
| ## |
| |
| Iterates through Verb_Array, and associated Point_Array and Conic_Weight. |
| Verb_Array, Point_Array, and Conic_Weight are returned unaltered. |
| |
| #Method RawIter() |
| #Line # constructs empty Path iterator ## |
| |
| Initializes RawIter with an empty Path. next() on RawIter returns kDone_Verb. |
| Call setPath to initialize SkPath::Iter at a later time. |
| |
| #Return RawIter of empty Path ## |
| |
| #NoExample |
| ## |
| ## |
| |
| #Method RawIter(const SkPath& path) |
| #Line # constructs with Path to iterate over ## |
| |
| |
| Sets RawIter to return elements of Verb_Array, Point_Array, and Conic_Weight in path. |
| |
| #Param path Path to iterate ## |
| |
| #Return RawIter of path ## |
| |
| #NoExample |
| ## |
| ## |
| |
| #Method void setPath(const SkPath& path) |
| #Line # sets Path to iterate over ## |
| |
| Sets SkPath::Iter to return elements of Verb_Array, Point_Array, and Conic_Weight in path. |
| |
| #Param path Path to iterate ## |
| |
| #NoExample |
| ## |
| ## |
| |
| #Method Verb next(SkPoint pts[4]) |
| #Line # returns next Verb and associated Points ## |
| Returns next Verb in Verb_Array, and advances RawIter. |
| When Verb_Array is exhausted, returns kDone_Verb. |
| Zero to four Points are stored in pts, depending on the returned Verb. |
| |
| #Param pts storage for Point data describing returned Verb ## |
| |
| #Return next Verb from Verb_Array ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPath path; |
| path.moveTo(50, 60); |
| path.quadTo(10, 20, 30, 40); |
| path.close(); |
| path.lineTo(30, 30); |
| path.conicTo(1, 2, 3, 4, .5f); |
| path.cubicTo(-1, -2, -3, -4, -5, -6); |
| SkPath::RawIter iter(path); |
| const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" }; |
| const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 }; |
| SkPath::Verb verb; |
| do { |
| SkPoint points[4]; |
| verb = iter.next(points); |
| SkDebugf("k%s_Verb ", verbStr[(int) verb]); |
| for (int i = 0; i < pointCount[(int) verb]; ++i) { |
| SkDebugf("{%1.8g, %1.8g}, ", points[i].fX, points[i].fY); |
| } |
| if (SkPath::kConic_Verb == verb) { |
| SkDebugf("weight = %g", iter.conicWeight()); |
| } |
| SkDebugf("\n"); |
| } while (SkPath::kDone_Verb != verb); |
| } |
| #StdOut |
| kMove_Verb {50, 60}, |
| kQuad_Verb {50, 60}, {10, 20}, {30, 40}, |
| kClose_Verb {50, 60}, |
| kMove_Verb {50, 60}, |
| kLine_Verb {50, 60}, {30, 30}, |
| kConic_Verb {30, 30}, {1, 2}, {3, 4}, weight = 0.5 |
| kCubic_Verb {3, 4}, {-1, -2}, {-3, -4}, {-5, -6}, |
| kDone_Verb |
| ## |
| ## |
| |
| #SeeAlso peek() |
| |
| ## |
| |
| #Method Verb peek() const |
| #Line # returns next Verb ## |
| Returns next Verb, but does not advance RawIter. |
| |
| #Return next Verb from Verb_Array ## |
| |
| #Example |
| SkPath path; |
| path.quadTo(10, 20, 30, 40); |
| path.conicTo(1, 2, 3, 4, .5f); |
| path.cubicTo(1, 2, 3, 4, .5, 6); |
| SkPath::RawIter iter(path); |
| SkPath::Verb verb, peek = iter.peek(); |
| const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" }; |
| do { |
| SkPoint points[4]; |
| verb = iter.next(points); |
| SkDebugf("peek %s %c= verb %s\n", verbStr[peek], peek == verb ? '=' : '!', verbStr[verb]); |
| peek = iter.peek(); |
| } while (SkPath::kDone_Verb != verb); |
| SkDebugf("peek %s %c= verb %s\n", verbStr[peek], peek == verb ? '=' : '!', verbStr[verb]); |
| #StdOut |
| #Volatile |
| peek Move == verb Move |
| peek Quad == verb Quad |
| peek Conic == verb Conic |
| peek Cubic == verb Cubic |
| peek Done == verb Done |
| peek Done == verb Done |
| ## |
| ## |
| |
| #Bug 6832 |
| StdOut is not really volatile, it just produces the wrong result. |
| A simple fix changes the output of hairlines and needs to be |
| investigated to see if the change is correct or not. |
| see change 21340 (abandoned for now) |
| |
| #SeeAlso next() |
| |
| ## |
| |
| #Method SkScalar conicWeight() const |
| #Line # returns Conic_Weight ## |
| |
| Returns Conic_Weight if next() returned kConic_Verb. |
| |
| If next() has not been called, or next() did not return kConic_Verb, |
| result is undefined. |
| |
| #Return Conic_Weight for Conic Points returned by next() ## |
| |
| #Example |
| void draw(SkCanvas* canvas) { |
| SkPath path; |
| path.conicTo(1, 2, 3, 4, .5f); |
| SkPath::RawIter iter(path); |
| SkPoint p[4]; |
| SkDebugf("first verb is " "%s" "move\n", SkPath::kMove_Verb == iter.next(p) ? "" : "not "); |
| SkDebugf("next verb is " "%s" "conic\n", SkPath::kConic_Verb == iter.next(p) ? "" : "not "); |
| SkDebugf("conic points: {%g,%g}, {%g,%g}, {%g,%g}\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY, |
| p[2].fX, p[2].fY); |
| SkDebugf("conic weight: %g\n", iter.conicWeight()); |
| } |
| #StdOut |
| first verb is move |
| next verb is conic |
| conic points: {0,0}, {1,2}, {3,4} |
| conic weight: 0.5 |
| ## |
| ## |
| |
| #SeeAlso Conic_Weight |
| |
| ## |
| |
| #Class RawIter ## |
| |
| #Class SkPath ## |
| |
| #Topic Path ## |
| |