epoger@google.com | ec3ed6a | 2011-07-28 14:26:00 +0000 | [diff] [blame] | 1 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 2 | /* |
epoger@google.com | ec3ed6a | 2011-07-28 14:26:00 +0000 | [diff] [blame] | 3 | * Copyright 2008 The Android Open Source Project |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 4 | * |
epoger@google.com | ec3ed6a | 2011-07-28 14:26:00 +0000 | [diff] [blame] | 5 | * Use of this source code is governed by a BSD-style license that can be |
| 6 | * found in the LICENSE file. |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 7 | */ |
| 8 | |
epoger@google.com | ec3ed6a | 2011-07-28 14:26:00 +0000 | [diff] [blame] | 9 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 10 | #include "SkPathMeasure.h" |
| 11 | #include "SkGeometry.h" |
| 12 | #include "SkPath.h" |
| 13 | #include "SkTSearch.h" |
| 14 | |
reed | 220f926 | 2014-12-17 08:21:04 -0800 | [diff] [blame] | 15 | // these must be 0,1,2,3 since they are in our 2-bit field |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 16 | enum { |
| 17 | kLine_SegType, |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 18 | kQuad_SegType, |
reed | 220f926 | 2014-12-17 08:21:04 -0800 | [diff] [blame] | 19 | kCubic_SegType, |
| 20 | kConic_SegType, |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 21 | }; |
| 22 | |
| 23 | #define kMaxTValue 32767 |
| 24 | |
| 25 | static inline SkScalar tValue2Scalar(int t) { |
| 26 | SkASSERT((unsigned)t <= kMaxTValue); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 27 | return t * 3.05185e-5f; // t / 32767 |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 28 | } |
| 29 | |
| 30 | SkScalar SkPathMeasure::Segment::getScalarT() const { |
| 31 | return tValue2Scalar(fTValue); |
| 32 | } |
| 33 | |
| 34 | const SkPathMeasure::Segment* SkPathMeasure::NextSegment(const Segment* seg) { |
| 35 | unsigned ptIndex = seg->fPtIndex; |
| 36 | |
| 37 | do { |
| 38 | ++seg; |
| 39 | } while (seg->fPtIndex == ptIndex); |
| 40 | return seg; |
| 41 | } |
| 42 | |
| 43 | /////////////////////////////////////////////////////////////////////////////// |
| 44 | |
| 45 | static inline int tspan_big_enough(int tspan) { |
| 46 | SkASSERT((unsigned)tspan <= kMaxTValue); |
| 47 | return tspan >> 10; |
| 48 | } |
| 49 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 50 | // can't use tangents, since we need [0..1..................2] to be seen |
| 51 | // as definitely not a line (it is when drawn, but not parametrically) |
| 52 | // so we compare midpoints |
| 53 | #define CHEAP_DIST_LIMIT (SK_Scalar1/2) // just made this value up |
| 54 | |
| 55 | static bool quad_too_curvy(const SkPoint pts[3]) { |
| 56 | // diff = (a/4 + b/2 + c/4) - (a/2 + c/2) |
| 57 | // diff = -a/4 + b/2 - c/4 |
| 58 | SkScalar dx = SkScalarHalf(pts[1].fX) - |
| 59 | SkScalarHalf(SkScalarHalf(pts[0].fX + pts[2].fX)); |
| 60 | SkScalar dy = SkScalarHalf(pts[1].fY) - |
| 61 | SkScalarHalf(SkScalarHalf(pts[0].fY + pts[2].fY)); |
| 62 | |
| 63 | SkScalar dist = SkMaxScalar(SkScalarAbs(dx), SkScalarAbs(dy)); |
| 64 | return dist > CHEAP_DIST_LIMIT; |
| 65 | } |
| 66 | |
| 67 | static bool cheap_dist_exceeds_limit(const SkPoint& pt, |
| 68 | SkScalar x, SkScalar y) { |
| 69 | SkScalar dist = SkMaxScalar(SkScalarAbs(x - pt.fX), SkScalarAbs(y - pt.fY)); |
| 70 | // just made up the 1/2 |
| 71 | return dist > CHEAP_DIST_LIMIT; |
| 72 | } |
| 73 | |
| 74 | static bool cubic_too_curvy(const SkPoint pts[4]) { |
| 75 | return cheap_dist_exceeds_limit(pts[1], |
| 76 | SkScalarInterp(pts[0].fX, pts[3].fX, SK_Scalar1/3), |
| 77 | SkScalarInterp(pts[0].fY, pts[3].fY, SK_Scalar1/3)) |
| 78 | || |
| 79 | cheap_dist_exceeds_limit(pts[2], |
| 80 | SkScalarInterp(pts[0].fX, pts[3].fX, SK_Scalar1*2/3), |
| 81 | SkScalarInterp(pts[0].fY, pts[3].fY, SK_Scalar1*2/3)); |
| 82 | } |
| 83 | |
| 84 | SkScalar SkPathMeasure::compute_quad_segs(const SkPoint pts[3], |
| 85 | SkScalar distance, int mint, int maxt, int ptIndex) { |
| 86 | if (tspan_big_enough(maxt - mint) && quad_too_curvy(pts)) { |
| 87 | SkPoint tmp[5]; |
| 88 | int halft = (mint + maxt) >> 1; |
| 89 | |
| 90 | SkChopQuadAtHalf(pts, tmp); |
| 91 | distance = this->compute_quad_segs(tmp, distance, mint, halft, ptIndex); |
| 92 | distance = this->compute_quad_segs(&tmp[2], distance, halft, maxt, ptIndex); |
| 93 | } else { |
| 94 | SkScalar d = SkPoint::Distance(pts[0], pts[2]); |
reed@google.com | ded4414 | 2012-04-27 20:22:07 +0000 | [diff] [blame] | 95 | SkScalar prevD = distance; |
| 96 | distance += d; |
| 97 | if (distance > prevD) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 98 | Segment* seg = fSegments.append(); |
| 99 | seg->fDistance = distance; |
| 100 | seg->fPtIndex = ptIndex; |
| 101 | seg->fType = kQuad_SegType; |
| 102 | seg->fTValue = maxt; |
| 103 | } |
| 104 | } |
| 105 | return distance; |
| 106 | } |
| 107 | |
reed | 220f926 | 2014-12-17 08:21:04 -0800 | [diff] [blame] | 108 | SkScalar SkPathMeasure::compute_conic_segs(const SkConic& conic, |
| 109 | SkScalar distance, int mint, int maxt, int ptIndex) { |
| 110 | if (tspan_big_enough(maxt - mint) && quad_too_curvy(conic.fPts)) { |
| 111 | SkConic tmp[2]; |
| 112 | conic.chop(tmp); |
| 113 | |
| 114 | int halft = (mint + maxt) >> 1; |
| 115 | distance = this->compute_conic_segs(tmp[0], distance, mint, halft, ptIndex); |
| 116 | distance = this->compute_conic_segs(tmp[1], distance, halft, maxt, ptIndex); |
| 117 | } else { |
| 118 | SkScalar d = SkPoint::Distance(conic.fPts[0], conic.fPts[2]); |
| 119 | SkScalar prevD = distance; |
| 120 | distance += d; |
| 121 | if (distance > prevD) { |
| 122 | Segment* seg = fSegments.append(); |
| 123 | seg->fDistance = distance; |
| 124 | seg->fPtIndex = ptIndex; |
| 125 | seg->fType = kConic_SegType; |
| 126 | seg->fTValue = maxt; |
| 127 | } |
| 128 | } |
| 129 | return distance; |
| 130 | } |
| 131 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 132 | SkScalar SkPathMeasure::compute_cubic_segs(const SkPoint pts[4], |
| 133 | SkScalar distance, int mint, int maxt, int ptIndex) { |
| 134 | if (tspan_big_enough(maxt - mint) && cubic_too_curvy(pts)) { |
| 135 | SkPoint tmp[7]; |
| 136 | int halft = (mint + maxt) >> 1; |
| 137 | |
| 138 | SkChopCubicAtHalf(pts, tmp); |
| 139 | distance = this->compute_cubic_segs(tmp, distance, mint, halft, ptIndex); |
| 140 | distance = this->compute_cubic_segs(&tmp[3], distance, halft, maxt, ptIndex); |
| 141 | } else { |
| 142 | SkScalar d = SkPoint::Distance(pts[0], pts[3]); |
reed@google.com | ded4414 | 2012-04-27 20:22:07 +0000 | [diff] [blame] | 143 | SkScalar prevD = distance; |
| 144 | distance += d; |
| 145 | if (distance > prevD) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 146 | Segment* seg = fSegments.append(); |
| 147 | seg->fDistance = distance; |
| 148 | seg->fPtIndex = ptIndex; |
| 149 | seg->fType = kCubic_SegType; |
| 150 | seg->fTValue = maxt; |
| 151 | } |
| 152 | } |
| 153 | return distance; |
| 154 | } |
| 155 | |
| 156 | void SkPathMeasure::buildSegments() { |
| 157 | SkPoint pts[4]; |
| 158 | int ptIndex = fFirstPtIndex; |
reed@google.com | fab1ddd | 2012-04-20 15:10:32 +0000 | [diff] [blame] | 159 | SkScalar distance = 0; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 160 | bool isClosed = fForceClosed; |
| 161 | bool firstMoveTo = ptIndex < 0; |
| 162 | Segment* seg; |
| 163 | |
reed@google.com | fab1ddd | 2012-04-20 15:10:32 +0000 | [diff] [blame] | 164 | /* Note: |
| 165 | * as we accumulate distance, we have to check that the result of += |
| 166 | * actually made it larger, since a very small delta might be > 0, but |
| 167 | * still have no effect on distance (if distance >>> delta). |
reed@google.com | ded4414 | 2012-04-27 20:22:07 +0000 | [diff] [blame] | 168 | * |
| 169 | * We do this check below, and in compute_quad_segs and compute_cubic_segs |
reed@google.com | fab1ddd | 2012-04-20 15:10:32 +0000 | [diff] [blame] | 170 | */ |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 171 | fSegments.reset(); |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 172 | bool done = false; |
| 173 | do { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 174 | switch (fIter.next(pts)) { |
| 175 | case SkPath::kMove_Verb: |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 176 | ptIndex += 1; |
| 177 | fPts.append(1, pts); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 178 | if (!firstMoveTo) { |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 179 | done = true; |
| 180 | break; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 181 | } |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 182 | firstMoveTo = false; |
| 183 | break; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 184 | |
reed@google.com | fab1ddd | 2012-04-20 15:10:32 +0000 | [diff] [blame] | 185 | case SkPath::kLine_Verb: { |
| 186 | SkScalar d = SkPoint::Distance(pts[0], pts[1]); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 187 | SkASSERT(d >= 0); |
reed@google.com | fab1ddd | 2012-04-20 15:10:32 +0000 | [diff] [blame] | 188 | SkScalar prevD = distance; |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 189 | distance += d; |
reed@google.com | fab1ddd | 2012-04-20 15:10:32 +0000 | [diff] [blame] | 190 | if (distance > prevD) { |
| 191 | seg = fSegments.append(); |
| 192 | seg->fDistance = distance; |
| 193 | seg->fPtIndex = ptIndex; |
| 194 | seg->fType = kLine_SegType; |
| 195 | seg->fTValue = kMaxTValue; |
| 196 | fPts.append(1, pts + 1); |
| 197 | ptIndex++; |
| 198 | } |
| 199 | } break; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 200 | |
reed@google.com | fab1ddd | 2012-04-20 15:10:32 +0000 | [diff] [blame] | 201 | case SkPath::kQuad_Verb: { |
| 202 | SkScalar prevD = distance; |
reed | 220f926 | 2014-12-17 08:21:04 -0800 | [diff] [blame] | 203 | distance = this->compute_quad_segs(pts, distance, 0, kMaxTValue, ptIndex); |
reed@google.com | fab1ddd | 2012-04-20 15:10:32 +0000 | [diff] [blame] | 204 | if (distance > prevD) { |
| 205 | fPts.append(2, pts + 1); |
| 206 | ptIndex += 2; |
| 207 | } |
| 208 | } break; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 209 | |
reed | 220f926 | 2014-12-17 08:21:04 -0800 | [diff] [blame] | 210 | case SkPath::kConic_Verb: { |
| 211 | const SkConic conic(pts, fIter.conicWeight()); |
| 212 | SkScalar prevD = distance; |
| 213 | distance = this->compute_conic_segs(conic, distance, 0, kMaxTValue, ptIndex); |
| 214 | if (distance > prevD) { |
| 215 | // we store the conic weight in our next point, followed by the last 2 pts |
| 216 | // thus to reconstitue a conic, you'd need to say |
| 217 | // SkConic(pts[0], pts[2], pts[3], weight = pts[1].fX) |
| 218 | fPts.append()->set(conic.fW, 0); |
| 219 | fPts.append(2, pts + 1); |
| 220 | ptIndex += 3; |
| 221 | } |
| 222 | } break; |
| 223 | |
reed@google.com | fab1ddd | 2012-04-20 15:10:32 +0000 | [diff] [blame] | 224 | case SkPath::kCubic_Verb: { |
| 225 | SkScalar prevD = distance; |
reed | 220f926 | 2014-12-17 08:21:04 -0800 | [diff] [blame] | 226 | distance = this->compute_cubic_segs(pts, distance, 0, kMaxTValue, ptIndex); |
reed@google.com | fab1ddd | 2012-04-20 15:10:32 +0000 | [diff] [blame] | 227 | if (distance > prevD) { |
| 228 | fPts.append(3, pts + 1); |
| 229 | ptIndex += 3; |
| 230 | } |
| 231 | } break; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 232 | |
| 233 | case SkPath::kClose_Verb: |
| 234 | isClosed = true; |
| 235 | break; |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 236 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 237 | case SkPath::kDone_Verb: |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 238 | done = true; |
| 239 | break; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 240 | } |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 241 | } while (!done); |
| 242 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 243 | fLength = distance; |
| 244 | fIsClosed = isClosed; |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 245 | fFirstPtIndex = ptIndex; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 246 | |
| 247 | #ifdef SK_DEBUG |
| 248 | { |
| 249 | const Segment* seg = fSegments.begin(); |
| 250 | const Segment* stop = fSegments.end(); |
| 251 | unsigned ptIndex = 0; |
| 252 | SkScalar distance = 0; |
| 253 | |
| 254 | while (seg < stop) { |
| 255 | SkASSERT(seg->fDistance > distance); |
| 256 | SkASSERT(seg->fPtIndex >= ptIndex); |
| 257 | SkASSERT(seg->fTValue > 0); |
| 258 | |
| 259 | const Segment* s = seg; |
| 260 | while (s < stop - 1 && s[0].fPtIndex == s[1].fPtIndex) { |
| 261 | SkASSERT(s[0].fType == s[1].fType); |
| 262 | SkASSERT(s[0].fTValue < s[1].fTValue); |
| 263 | s += 1; |
| 264 | } |
| 265 | |
| 266 | distance = seg->fDistance; |
| 267 | ptIndex = seg->fPtIndex; |
| 268 | seg += 1; |
| 269 | } |
| 270 | // SkDebugf("\n"); |
| 271 | } |
| 272 | #endif |
| 273 | } |
| 274 | |
reed@google.com | 5b94153 | 2012-05-17 15:31:43 +0000 | [diff] [blame] | 275 | static void compute_pos_tan(const SkPoint pts[], int segType, |
| 276 | SkScalar t, SkPoint* pos, SkVector* tangent) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 277 | switch (segType) { |
| 278 | case kLine_SegType: |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 279 | if (pos) { |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 280 | pos->set(SkScalarInterp(pts[0].fX, pts[1].fX, t), |
reed@google.com | 5b94153 | 2012-05-17 15:31:43 +0000 | [diff] [blame] | 281 | SkScalarInterp(pts[0].fY, pts[1].fY, t)); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 282 | } |
| 283 | if (tangent) { |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 284 | tangent->setNormalize(pts[1].fX - pts[0].fX, pts[1].fY - pts[0].fY); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 285 | } |
| 286 | break; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 287 | case kQuad_SegType: |
| 288 | SkEvalQuadAt(pts, t, pos, tangent); |
| 289 | if (tangent) { |
| 290 | tangent->normalize(); |
| 291 | } |
| 292 | break; |
reed | 220f926 | 2014-12-17 08:21:04 -0800 | [diff] [blame] | 293 | case kConic_SegType: { |
| 294 | SkConic(pts[0], pts[2], pts[3], pts[1].fX).evalAt(t, pos, tangent); |
| 295 | if (tangent) { |
| 296 | tangent->normalize(); |
| 297 | } |
| 298 | } break; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 299 | case kCubic_SegType: |
halcanary | 96fcdcc | 2015-08-27 07:41:13 -0700 | [diff] [blame] | 300 | SkEvalCubicAt(pts, t, pos, tangent, nullptr); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 301 | if (tangent) { |
| 302 | tangent->normalize(); |
| 303 | } |
| 304 | break; |
| 305 | default: |
tomhudson@google.com | 0c00f21 | 2011-12-28 14:59:50 +0000 | [diff] [blame] | 306 | SkDEBUGFAIL("unknown segType"); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 307 | } |
| 308 | } |
| 309 | |
reed@google.com | 5b94153 | 2012-05-17 15:31:43 +0000 | [diff] [blame] | 310 | static void seg_to(const SkPoint pts[], int segType, |
| 311 | SkScalar startT, SkScalar stopT, SkPath* dst) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 312 | SkASSERT(startT >= 0 && startT <= SK_Scalar1); |
| 313 | SkASSERT(stopT >= 0 && stopT <= SK_Scalar1); |
| 314 | SkASSERT(startT <= stopT); |
| 315 | |
reed@google.com | de1837b | 2012-05-21 16:47:43 +0000 | [diff] [blame] | 316 | if (startT == stopT) { |
caryclark | 5cb00a9 | 2015-08-26 09:04:55 -0700 | [diff] [blame] | 317 | /* if the dash as a zero-length on segment, add a corresponding zero-length line. |
| 318 | The stroke code will add end caps to zero length lines as appropriate */ |
| 319 | SkPoint lastPt; |
| 320 | SkAssertResult(dst->getLastPt(&lastPt)); |
| 321 | dst->lineTo(lastPt); |
| 322 | return; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 323 | } |
| 324 | |
reed | 220f926 | 2014-12-17 08:21:04 -0800 | [diff] [blame] | 325 | SkPoint tmp0[7], tmp1[7]; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 326 | |
| 327 | switch (segType) { |
| 328 | case kLine_SegType: |
reed@google.com | f33612b | 2013-02-20 14:55:20 +0000 | [diff] [blame] | 329 | if (SK_Scalar1 == stopT) { |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 330 | dst->lineTo(pts[1]); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 331 | } else { |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 332 | dst->lineTo(SkScalarInterp(pts[0].fX, pts[1].fX, stopT), |
| 333 | SkScalarInterp(pts[0].fY, pts[1].fY, stopT)); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 334 | } |
| 335 | break; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 336 | case kQuad_SegType: |
reed@google.com | f33612b | 2013-02-20 14:55:20 +0000 | [diff] [blame] | 337 | if (0 == startT) { |
| 338 | if (SK_Scalar1 == stopT) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 339 | dst->quadTo(pts[1], pts[2]); |
| 340 | } else { |
| 341 | SkChopQuadAt(pts, tmp0, stopT); |
| 342 | dst->quadTo(tmp0[1], tmp0[2]); |
| 343 | } |
| 344 | } else { |
| 345 | SkChopQuadAt(pts, tmp0, startT); |
reed@google.com | f33612b | 2013-02-20 14:55:20 +0000 | [diff] [blame] | 346 | if (SK_Scalar1 == stopT) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 347 | dst->quadTo(tmp0[3], tmp0[4]); |
| 348 | } else { |
reed | 80ea19c | 2015-05-12 10:37:34 -0700 | [diff] [blame] | 349 | SkChopQuadAt(&tmp0[2], tmp1, (stopT - startT) / (1 - startT)); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 350 | dst->quadTo(tmp1[1], tmp1[2]); |
| 351 | } |
| 352 | } |
| 353 | break; |
reed | 220f926 | 2014-12-17 08:21:04 -0800 | [diff] [blame] | 354 | case kConic_SegType: { |
| 355 | SkConic conic(pts[0], pts[2], pts[3], pts[1].fX); |
| 356 | |
| 357 | if (0 == startT) { |
| 358 | if (SK_Scalar1 == stopT) { |
| 359 | dst->conicTo(conic.fPts[1], conic.fPts[2], conic.fW); |
| 360 | } else { |
| 361 | SkConic tmp[2]; |
| 362 | conic.chopAt(stopT, tmp); |
| 363 | dst->conicTo(tmp[0].fPts[1], tmp[0].fPts[2], tmp[0].fW); |
| 364 | } |
| 365 | } else { |
| 366 | SkConic tmp1[2]; |
| 367 | conic.chopAt(startT, tmp1); |
| 368 | if (SK_Scalar1 == stopT) { |
| 369 | dst->conicTo(tmp1[1].fPts[1], tmp1[1].fPts[2], tmp1[1].fW); |
| 370 | } else { |
| 371 | SkConic tmp2[2]; |
| 372 | tmp1[1].chopAt((stopT - startT) / (SK_Scalar1 - startT), tmp2); |
| 373 | dst->conicTo(tmp2[0].fPts[1], tmp2[0].fPts[2], tmp2[0].fW); |
| 374 | } |
| 375 | } |
| 376 | } break; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 377 | case kCubic_SegType: |
reed@google.com | f33612b | 2013-02-20 14:55:20 +0000 | [diff] [blame] | 378 | if (0 == startT) { |
| 379 | if (SK_Scalar1 == stopT) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 380 | dst->cubicTo(pts[1], pts[2], pts[3]); |
| 381 | } else { |
| 382 | SkChopCubicAt(pts, tmp0, stopT); |
| 383 | dst->cubicTo(tmp0[1], tmp0[2], tmp0[3]); |
| 384 | } |
| 385 | } else { |
| 386 | SkChopCubicAt(pts, tmp0, startT); |
reed@google.com | f33612b | 2013-02-20 14:55:20 +0000 | [diff] [blame] | 387 | if (SK_Scalar1 == stopT) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 388 | dst->cubicTo(tmp0[4], tmp0[5], tmp0[6]); |
| 389 | } else { |
reed | 80ea19c | 2015-05-12 10:37:34 -0700 | [diff] [blame] | 390 | SkChopCubicAt(&tmp0[3], tmp1, (stopT - startT) / (1 - startT)); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 391 | dst->cubicTo(tmp1[1], tmp1[2], tmp1[3]); |
| 392 | } |
| 393 | } |
| 394 | break; |
| 395 | default: |
tomhudson@google.com | 0c00f21 | 2011-12-28 14:59:50 +0000 | [diff] [blame] | 396 | SkDEBUGFAIL("unknown segType"); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 397 | sk_throw(); |
| 398 | } |
| 399 | } |
| 400 | |
| 401 | //////////////////////////////////////////////////////////////////////////////// |
| 402 | //////////////////////////////////////////////////////////////////////////////// |
| 403 | |
| 404 | SkPathMeasure::SkPathMeasure() { |
halcanary | 96fcdcc | 2015-08-27 07:41:13 -0700 | [diff] [blame] | 405 | fPath = nullptr; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 406 | fLength = -1; // signal we need to compute it |
| 407 | fForceClosed = false; |
| 408 | fFirstPtIndex = -1; |
| 409 | } |
| 410 | |
| 411 | SkPathMeasure::SkPathMeasure(const SkPath& path, bool forceClosed) { |
| 412 | fPath = &path; |
| 413 | fLength = -1; // signal we need to compute it |
| 414 | fForceClosed = forceClosed; |
| 415 | fFirstPtIndex = -1; |
| 416 | |
| 417 | fIter.setPath(path, forceClosed); |
| 418 | } |
| 419 | |
| 420 | SkPathMeasure::~SkPathMeasure() {} |
| 421 | |
| 422 | /** Assign a new path, or null to have none. |
| 423 | */ |
| 424 | void SkPathMeasure::setPath(const SkPath* path, bool forceClosed) { |
| 425 | fPath = path; |
| 426 | fLength = -1; // signal we need to compute it |
| 427 | fForceClosed = forceClosed; |
| 428 | fFirstPtIndex = -1; |
| 429 | |
| 430 | if (path) { |
| 431 | fIter.setPath(*path, forceClosed); |
| 432 | } |
| 433 | fSegments.reset(); |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 434 | fPts.reset(); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 435 | } |
| 436 | |
| 437 | SkScalar SkPathMeasure::getLength() { |
halcanary | 96fcdcc | 2015-08-27 07:41:13 -0700 | [diff] [blame] | 438 | if (fPath == nullptr) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 439 | return 0; |
| 440 | } |
| 441 | if (fLength < 0) { |
| 442 | this->buildSegments(); |
| 443 | } |
| 444 | SkASSERT(fLength >= 0); |
| 445 | return fLength; |
| 446 | } |
| 447 | |
reed | 83e22e4 | 2015-03-26 04:13:08 -0700 | [diff] [blame] | 448 | template <typename T, typename K> |
| 449 | int SkTKSearch(const T base[], int count, const K& key) { |
| 450 | SkASSERT(count >= 0); |
| 451 | if (count <= 0) { |
| 452 | return ~0; |
| 453 | } |
| 454 | |
halcanary | 96fcdcc | 2015-08-27 07:41:13 -0700 | [diff] [blame] | 455 | SkASSERT(base != nullptr); // base may be nullptr if count is zero |
reed | 83e22e4 | 2015-03-26 04:13:08 -0700 | [diff] [blame] | 456 | |
| 457 | int lo = 0; |
| 458 | int hi = count - 1; |
| 459 | |
| 460 | while (lo < hi) { |
| 461 | int mid = (hi + lo) >> 1; |
| 462 | if (base[mid].fDistance < key) { |
| 463 | lo = mid + 1; |
| 464 | } else { |
| 465 | hi = mid; |
| 466 | } |
| 467 | } |
| 468 | |
| 469 | if (base[hi].fDistance < key) { |
| 470 | hi += 1; |
| 471 | hi = ~hi; |
| 472 | } else if (key < base[hi].fDistance) { |
| 473 | hi = ~hi; |
| 474 | } |
| 475 | return hi; |
| 476 | } |
| 477 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 478 | const SkPathMeasure::Segment* SkPathMeasure::distanceToSegment( |
| 479 | SkScalar distance, SkScalar* t) { |
| 480 | SkDEBUGCODE(SkScalar length = ) this->getLength(); |
| 481 | SkASSERT(distance >= 0 && distance <= length); |
| 482 | |
| 483 | const Segment* seg = fSegments.begin(); |
| 484 | int count = fSegments.count(); |
| 485 | |
reed | 83e22e4 | 2015-03-26 04:13:08 -0700 | [diff] [blame] | 486 | int index = SkTKSearch<Segment, SkScalar>(seg, count, distance); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 487 | // don't care if we hit an exact match or not, so we xor index if it is negative |
| 488 | index ^= (index >> 31); |
| 489 | seg = &seg[index]; |
| 490 | |
| 491 | // now interpolate t-values with the prev segment (if possible) |
| 492 | SkScalar startT = 0, startD = 0; |
| 493 | // check if the prev segment is legal, and references the same set of points |
| 494 | if (index > 0) { |
| 495 | startD = seg[-1].fDistance; |
| 496 | if (seg[-1].fPtIndex == seg->fPtIndex) { |
| 497 | SkASSERT(seg[-1].fType == seg->fType); |
| 498 | startT = seg[-1].getScalarT(); |
| 499 | } |
| 500 | } |
| 501 | |
| 502 | SkASSERT(seg->getScalarT() > startT); |
| 503 | SkASSERT(distance >= startD); |
| 504 | SkASSERT(seg->fDistance > startD); |
| 505 | |
| 506 | *t = startT + SkScalarMulDiv(seg->getScalarT() - startT, |
| 507 | distance - startD, |
| 508 | seg->fDistance - startD); |
| 509 | return seg; |
| 510 | } |
| 511 | |
| 512 | bool SkPathMeasure::getPosTan(SkScalar distance, SkPoint* pos, |
| 513 | SkVector* tangent) { |
halcanary | 96fcdcc | 2015-08-27 07:41:13 -0700 | [diff] [blame] | 514 | if (nullptr == fPath) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 515 | return false; |
| 516 | } |
| 517 | |
| 518 | SkScalar length = this->getLength(); // call this to force computing it |
| 519 | int count = fSegments.count(); |
| 520 | |
| 521 | if (count == 0 || length == 0) { |
schenney@chromium.org | a6d04d9 | 2012-01-18 18:02:10 +0000 | [diff] [blame] | 522 | return false; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 523 | } |
| 524 | |
| 525 | // pin the distance to a legal range |
| 526 | if (distance < 0) { |
| 527 | distance = 0; |
| 528 | } else if (distance > length) { |
| 529 | distance = length; |
| 530 | } |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 531 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 532 | SkScalar t; |
| 533 | const Segment* seg = this->distanceToSegment(distance, &t); |
| 534 | |
reed@google.com | 5b94153 | 2012-05-17 15:31:43 +0000 | [diff] [blame] | 535 | compute_pos_tan(&fPts[seg->fPtIndex], seg->fType, t, pos, tangent); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 536 | return true; |
| 537 | } |
| 538 | |
| 539 | bool SkPathMeasure::getMatrix(SkScalar distance, SkMatrix* matrix, |
| 540 | MatrixFlags flags) { |
halcanary | 96fcdcc | 2015-08-27 07:41:13 -0700 | [diff] [blame] | 541 | if (nullptr == fPath) { |
djsollen@google.com | dfef456 | 2012-11-01 12:15:12 +0000 | [diff] [blame] | 542 | return false; |
| 543 | } |
| 544 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 545 | SkPoint position; |
| 546 | SkVector tangent; |
| 547 | |
| 548 | if (this->getPosTan(distance, &position, &tangent)) { |
| 549 | if (matrix) { |
| 550 | if (flags & kGetTangent_MatrixFlag) { |
| 551 | matrix->setSinCos(tangent.fY, tangent.fX, 0, 0); |
| 552 | } else { |
| 553 | matrix->reset(); |
| 554 | } |
| 555 | if (flags & kGetPosition_MatrixFlag) { |
| 556 | matrix->postTranslate(position.fX, position.fY); |
| 557 | } |
| 558 | } |
| 559 | return true; |
| 560 | } |
| 561 | return false; |
| 562 | } |
| 563 | |
| 564 | bool SkPathMeasure::getSegment(SkScalar startD, SkScalar stopD, SkPath* dst, |
| 565 | bool startWithMoveTo) { |
| 566 | SkASSERT(dst); |
| 567 | |
| 568 | SkScalar length = this->getLength(); // ensure we have built our segments |
| 569 | |
| 570 | if (startD < 0) { |
| 571 | startD = 0; |
| 572 | } |
| 573 | if (stopD > length) { |
| 574 | stopD = length; |
| 575 | } |
caryclark | 5cb00a9 | 2015-08-26 09:04:55 -0700 | [diff] [blame] | 576 | if (startD > stopD) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 577 | return false; |
| 578 | } |
| 579 | |
| 580 | SkPoint p; |
| 581 | SkScalar startT, stopT; |
| 582 | const Segment* seg = this->distanceToSegment(startD, &startT); |
| 583 | const Segment* stopSeg = this->distanceToSegment(stopD, &stopT); |
| 584 | SkASSERT(seg <= stopSeg); |
| 585 | |
| 586 | if (startWithMoveTo) { |
halcanary | 96fcdcc | 2015-08-27 07:41:13 -0700 | [diff] [blame] | 587 | compute_pos_tan(&fPts[seg->fPtIndex], seg->fType, startT, &p, nullptr); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 588 | dst->moveTo(p); |
| 589 | } |
| 590 | |
| 591 | if (seg->fPtIndex == stopSeg->fPtIndex) { |
reed@google.com | 5b94153 | 2012-05-17 15:31:43 +0000 | [diff] [blame] | 592 | seg_to(&fPts[seg->fPtIndex], seg->fType, startT, stopT, dst); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 593 | } else { |
| 594 | do { |
reed@google.com | 5b94153 | 2012-05-17 15:31:43 +0000 | [diff] [blame] | 595 | seg_to(&fPts[seg->fPtIndex], seg->fType, startT, SK_Scalar1, dst); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 596 | seg = SkPathMeasure::NextSegment(seg); |
| 597 | startT = 0; |
| 598 | } while (seg->fPtIndex < stopSeg->fPtIndex); |
reed@google.com | 5b94153 | 2012-05-17 15:31:43 +0000 | [diff] [blame] | 599 | seg_to(&fPts[seg->fPtIndex], seg->fType, 0, stopT, dst); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 600 | } |
| 601 | return true; |
| 602 | } |
| 603 | |
| 604 | bool SkPathMeasure::isClosed() { |
| 605 | (void)this->getLength(); |
| 606 | return fIsClosed; |
| 607 | } |
| 608 | |
| 609 | /** Move to the next contour in the path. Return true if one exists, or false if |
| 610 | we're done with the path. |
| 611 | */ |
| 612 | bool SkPathMeasure::nextContour() { |
| 613 | fLength = -1; |
| 614 | return this->getLength() > 0; |
| 615 | } |
| 616 | |
| 617 | /////////////////////////////////////////////////////////////////////////////// |
| 618 | /////////////////////////////////////////////////////////////////////////////// |
| 619 | |
| 620 | #ifdef SK_DEBUG |
| 621 | |
| 622 | void SkPathMeasure::dump() { |
| 623 | SkDebugf("pathmeas: length=%g, segs=%d\n", fLength, fSegments.count()); |
| 624 | |
| 625 | for (int i = 0; i < fSegments.count(); i++) { |
| 626 | const Segment* seg = &fSegments[i]; |
| 627 | SkDebugf("pathmeas: seg[%d] distance=%g, point=%d, t=%g, type=%d\n", |
| 628 | i, seg->fDistance, seg->fPtIndex, seg->getScalarT(), |
| 629 | seg->fType); |
| 630 | } |
| 631 | } |
| 632 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 633 | #endif |