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 "SkStrokerPriv.h" |
| 11 | #include "SkGeometry.h" |
| 12 | #include "SkPath.h" |
| 13 | |
| 14 | #define kMaxQuadSubdivide 5 |
| 15 | #define kMaxCubicSubdivide 4 |
| 16 | |
| 17 | static inline bool degenerate_vector(const SkVector& v) { |
reed@google.com | 55b5f4b | 2011-09-07 12:23:41 +0000 | [diff] [blame] | 18 | return !SkPoint::CanNormalize(v.fX, v.fY); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 19 | } |
| 20 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 21 | static inline bool normals_too_curvy(const SkVector& norm0, SkVector& norm1) { |
| 22 | /* root2/2 is a 45-degree angle |
| 23 | make this constant bigger for more subdivisions (but not >= 1) |
| 24 | */ |
| 25 | static const SkScalar kFlatEnoughNormalDotProd = |
| 26 | SK_ScalarSqrt2/2 + SK_Scalar1/10; |
| 27 | |
| 28 | SkASSERT(kFlatEnoughNormalDotProd > 0 && |
| 29 | kFlatEnoughNormalDotProd < SK_Scalar1); |
| 30 | |
| 31 | return SkPoint::DotProduct(norm0, norm1) <= kFlatEnoughNormalDotProd; |
| 32 | } |
| 33 | |
| 34 | static inline bool normals_too_pinchy(const SkVector& norm0, SkVector& norm1) { |
| 35 | static const SkScalar kTooPinchyNormalDotProd = -SK_Scalar1 * 999 / 1000; |
| 36 | |
| 37 | return SkPoint::DotProduct(norm0, norm1) <= kTooPinchyNormalDotProd; |
| 38 | } |
| 39 | |
| 40 | static bool set_normal_unitnormal(const SkPoint& before, const SkPoint& after, |
| 41 | SkScalar radius, |
| 42 | SkVector* normal, SkVector* unitNormal) { |
| 43 | if (!unitNormal->setNormalize(after.fX - before.fX, after.fY - before.fY)) { |
| 44 | return false; |
| 45 | } |
| 46 | unitNormal->rotateCCW(); |
| 47 | unitNormal->scale(radius, normal); |
| 48 | return true; |
| 49 | } |
| 50 | |
| 51 | static bool set_normal_unitnormal(const SkVector& vec, |
| 52 | SkScalar radius, |
| 53 | SkVector* normal, SkVector* unitNormal) { |
| 54 | if (!unitNormal->setNormalize(vec.fX, vec.fY)) { |
| 55 | return false; |
| 56 | } |
| 57 | unitNormal->rotateCCW(); |
| 58 | unitNormal->scale(radius, normal); |
| 59 | return true; |
| 60 | } |
| 61 | |
| 62 | /////////////////////////////////////////////////////////////////////////////// |
| 63 | |
| 64 | class SkPathStroker { |
| 65 | public: |
| 66 | SkPathStroker(SkScalar radius, SkScalar miterLimit, SkPaint::Cap cap, |
| 67 | SkPaint::Join join); |
| 68 | |
| 69 | void moveTo(const SkPoint&); |
| 70 | void lineTo(const SkPoint&); |
| 71 | void quadTo(const SkPoint&, const SkPoint&); |
| 72 | void cubicTo(const SkPoint&, const SkPoint&, const SkPoint&); |
| 73 | void close(bool isLine) { this->finishContour(true, isLine); } |
| 74 | |
| 75 | void done(SkPath* dst, bool isLine) { |
| 76 | this->finishContour(false, isLine); |
| 77 | fOuter.addPath(fExtra); |
| 78 | dst->swap(fOuter); |
| 79 | } |
| 80 | |
| 81 | private: |
| 82 | SkScalar fRadius; |
| 83 | SkScalar fInvMiterLimit; |
| 84 | |
| 85 | SkVector fFirstNormal, fPrevNormal, fFirstUnitNormal, fPrevUnitNormal; |
| 86 | SkPoint fFirstPt, fPrevPt; // on original path |
| 87 | SkPoint fFirstOuterPt; |
| 88 | int fSegmentCount; |
| 89 | bool fPrevIsLine; |
| 90 | |
| 91 | SkStrokerPriv::CapProc fCapper; |
| 92 | SkStrokerPriv::JoinProc fJoiner; |
| 93 | |
| 94 | SkPath fInner, fOuter; // outer is our working answer, inner is temp |
| 95 | SkPath fExtra; // added as extra complete contours |
| 96 | |
| 97 | void finishContour(bool close, bool isLine); |
| 98 | void preJoinTo(const SkPoint&, SkVector* normal, SkVector* unitNormal, |
| 99 | bool isLine); |
| 100 | void postJoinTo(const SkPoint&, const SkVector& normal, |
| 101 | const SkVector& unitNormal); |
| 102 | |
| 103 | void line_to(const SkPoint& currPt, const SkVector& normal); |
| 104 | void quad_to(const SkPoint pts[3], |
| 105 | const SkVector& normalAB, const SkVector& unitNormalAB, |
| 106 | SkVector* normalBC, SkVector* unitNormalBC, |
| 107 | int subDivide); |
| 108 | void cubic_to(const SkPoint pts[4], |
| 109 | const SkVector& normalAB, const SkVector& unitNormalAB, |
| 110 | SkVector* normalCD, SkVector* unitNormalCD, |
| 111 | int subDivide); |
| 112 | }; |
| 113 | |
| 114 | /////////////////////////////////////////////////////////////////////////////// |
| 115 | |
| 116 | void SkPathStroker::preJoinTo(const SkPoint& currPt, SkVector* normal, |
| 117 | SkVector* unitNormal, bool currIsLine) { |
| 118 | SkASSERT(fSegmentCount >= 0); |
| 119 | |
| 120 | SkScalar prevX = fPrevPt.fX; |
| 121 | SkScalar prevY = fPrevPt.fY; |
| 122 | |
| 123 | SkAssertResult(set_normal_unitnormal(fPrevPt, currPt, fRadius, normal, |
| 124 | unitNormal)); |
| 125 | |
| 126 | if (fSegmentCount == 0) { |
| 127 | fFirstNormal = *normal; |
| 128 | fFirstUnitNormal = *unitNormal; |
| 129 | fFirstOuterPt.set(prevX + normal->fX, prevY + normal->fY); |
| 130 | |
| 131 | fOuter.moveTo(fFirstOuterPt.fX, fFirstOuterPt.fY); |
| 132 | fInner.moveTo(prevX - normal->fX, prevY - normal->fY); |
| 133 | } else { // we have a previous segment |
| 134 | fJoiner(&fOuter, &fInner, fPrevUnitNormal, fPrevPt, *unitNormal, |
| 135 | fRadius, fInvMiterLimit, fPrevIsLine, currIsLine); |
| 136 | } |
| 137 | fPrevIsLine = currIsLine; |
| 138 | } |
| 139 | |
| 140 | void SkPathStroker::postJoinTo(const SkPoint& currPt, const SkVector& normal, |
| 141 | const SkVector& unitNormal) { |
| 142 | fPrevPt = currPt; |
| 143 | fPrevUnitNormal = unitNormal; |
| 144 | fPrevNormal = normal; |
| 145 | fSegmentCount += 1; |
| 146 | } |
| 147 | |
| 148 | void SkPathStroker::finishContour(bool close, bool currIsLine) { |
| 149 | if (fSegmentCount > 0) { |
| 150 | SkPoint pt; |
| 151 | |
| 152 | if (close) { |
| 153 | fJoiner(&fOuter, &fInner, fPrevUnitNormal, fPrevPt, |
| 154 | fFirstUnitNormal, fRadius, fInvMiterLimit, |
| 155 | fPrevIsLine, currIsLine); |
| 156 | fOuter.close(); |
| 157 | // now add fInner as its own contour |
| 158 | fInner.getLastPt(&pt); |
| 159 | fOuter.moveTo(pt.fX, pt.fY); |
| 160 | fOuter.reversePathTo(fInner); |
| 161 | fOuter.close(); |
| 162 | } else { // add caps to start and end |
| 163 | // cap the end |
| 164 | fInner.getLastPt(&pt); |
| 165 | fCapper(&fOuter, fPrevPt, fPrevNormal, pt, |
| 166 | currIsLine ? &fInner : NULL); |
| 167 | fOuter.reversePathTo(fInner); |
| 168 | // cap the start |
| 169 | fCapper(&fOuter, fFirstPt, -fFirstNormal, fFirstOuterPt, |
| 170 | fPrevIsLine ? &fInner : NULL); |
| 171 | fOuter.close(); |
| 172 | } |
| 173 | } |
| 174 | fInner.reset(); |
| 175 | fSegmentCount = -1; |
| 176 | } |
| 177 | |
| 178 | /////////////////////////////////////////////////////////////////////////////// |
| 179 | |
| 180 | SkPathStroker::SkPathStroker(SkScalar radius, SkScalar miterLimit, |
| 181 | SkPaint::Cap cap, SkPaint::Join join) |
| 182 | : fRadius(radius) { |
| 183 | |
| 184 | /* This is only used when join is miter_join, but we initialize it here |
| 185 | so that it is always defined, to fis valgrind warnings. |
| 186 | */ |
| 187 | fInvMiterLimit = 0; |
| 188 | |
| 189 | if (join == SkPaint::kMiter_Join) { |
| 190 | if (miterLimit <= SK_Scalar1) { |
| 191 | join = SkPaint::kBevel_Join; |
| 192 | } else { |
| 193 | fInvMiterLimit = SkScalarInvert(miterLimit); |
| 194 | } |
| 195 | } |
| 196 | fCapper = SkStrokerPriv::CapFactory(cap); |
| 197 | fJoiner = SkStrokerPriv::JoinFactory(join); |
| 198 | fSegmentCount = -1; |
| 199 | fPrevIsLine = false; |
| 200 | } |
| 201 | |
| 202 | void SkPathStroker::moveTo(const SkPoint& pt) { |
| 203 | if (fSegmentCount > 0) { |
| 204 | this->finishContour(false, false); |
| 205 | } |
| 206 | fSegmentCount = 0; |
| 207 | fFirstPt = fPrevPt = pt; |
| 208 | } |
| 209 | |
| 210 | void SkPathStroker::line_to(const SkPoint& currPt, const SkVector& normal) { |
| 211 | fOuter.lineTo(currPt.fX + normal.fX, currPt.fY + normal.fY); |
| 212 | fInner.lineTo(currPt.fX - normal.fX, currPt.fY - normal.fY); |
| 213 | } |
| 214 | |
| 215 | void SkPathStroker::lineTo(const SkPoint& currPt) { |
schenney@chromium.org | 4da06ab | 2011-12-20 15:14:18 +0000 | [diff] [blame] | 216 | if (SkPath::IsLineDegenerate(fPrevPt, currPt)) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 217 | return; |
| 218 | } |
| 219 | SkVector normal, unitNormal; |
| 220 | |
| 221 | this->preJoinTo(currPt, &normal, &unitNormal, true); |
| 222 | this->line_to(currPt, normal); |
| 223 | this->postJoinTo(currPt, normal, unitNormal); |
| 224 | } |
| 225 | |
| 226 | void SkPathStroker::quad_to(const SkPoint pts[3], |
| 227 | const SkVector& normalAB, const SkVector& unitNormalAB, |
| 228 | SkVector* normalBC, SkVector* unitNormalBC, |
| 229 | int subDivide) { |
| 230 | if (!set_normal_unitnormal(pts[1], pts[2], fRadius, |
| 231 | normalBC, unitNormalBC)) { |
| 232 | // pts[1] nearly equals pts[2], so just draw a line to pts[2] |
| 233 | this->line_to(pts[2], normalAB); |
| 234 | *normalBC = normalAB; |
| 235 | *unitNormalBC = unitNormalAB; |
| 236 | return; |
| 237 | } |
| 238 | |
| 239 | if (--subDivide >= 0 && normals_too_curvy(unitNormalAB, *unitNormalBC)) { |
| 240 | SkPoint tmp[5]; |
| 241 | SkVector norm, unit; |
| 242 | |
| 243 | SkChopQuadAtHalf(pts, tmp); |
| 244 | this->quad_to(&tmp[0], normalAB, unitNormalAB, &norm, &unit, subDivide); |
| 245 | this->quad_to(&tmp[2], norm, unit, normalBC, unitNormalBC, subDivide); |
| 246 | } else { |
| 247 | SkVector normalB, unitB; |
| 248 | SkAssertResult(set_normal_unitnormal(pts[0], pts[2], fRadius, |
| 249 | &normalB, &unitB)); |
| 250 | |
| 251 | fOuter.quadTo( pts[1].fX + normalB.fX, pts[1].fY + normalB.fY, |
| 252 | pts[2].fX + normalBC->fX, pts[2].fY + normalBC->fY); |
| 253 | fInner.quadTo( pts[1].fX - normalB.fX, pts[1].fY - normalB.fY, |
| 254 | pts[2].fX - normalBC->fX, pts[2].fY - normalBC->fY); |
| 255 | } |
| 256 | } |
| 257 | |
| 258 | void SkPathStroker::cubic_to(const SkPoint pts[4], |
| 259 | const SkVector& normalAB, const SkVector& unitNormalAB, |
| 260 | SkVector* normalCD, SkVector* unitNormalCD, |
| 261 | int subDivide) { |
| 262 | SkVector ab = pts[1] - pts[0]; |
| 263 | SkVector cd = pts[3] - pts[2]; |
| 264 | SkVector normalBC, unitNormalBC; |
| 265 | |
| 266 | bool degenerateAB = degenerate_vector(ab); |
| 267 | bool degenerateCD = degenerate_vector(cd); |
| 268 | |
| 269 | if (degenerateAB && degenerateCD) { |
| 270 | DRAW_LINE: |
| 271 | this->line_to(pts[3], normalAB); |
| 272 | *normalCD = normalAB; |
| 273 | *unitNormalCD = unitNormalAB; |
| 274 | return; |
| 275 | } |
| 276 | |
| 277 | if (degenerateAB) { |
| 278 | ab = pts[2] - pts[0]; |
| 279 | degenerateAB = degenerate_vector(ab); |
| 280 | } |
| 281 | if (degenerateCD) { |
| 282 | cd = pts[3] - pts[1]; |
| 283 | degenerateCD = degenerate_vector(cd); |
| 284 | } |
| 285 | if (degenerateAB || degenerateCD) { |
| 286 | goto DRAW_LINE; |
| 287 | } |
| 288 | SkAssertResult(set_normal_unitnormal(cd, fRadius, normalCD, unitNormalCD)); |
| 289 | bool degenerateBC = !set_normal_unitnormal(pts[1], pts[2], fRadius, |
| 290 | &normalBC, &unitNormalBC); |
| 291 | |
reed@android.com | 0ea42c1 | 2009-06-17 19:21:01 +0000 | [diff] [blame] | 292 | if (degenerateBC || normals_too_curvy(unitNormalAB, unitNormalBC) || |
| 293 | normals_too_curvy(unitNormalBC, *unitNormalCD)) { |
| 294 | // subdivide if we can |
| 295 | if (--subDivide < 0) { |
| 296 | goto DRAW_LINE; |
| 297 | } |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 298 | SkPoint tmp[7]; |
| 299 | SkVector norm, unit, dummy, unitDummy; |
| 300 | |
| 301 | SkChopCubicAtHalf(pts, tmp); |
| 302 | this->cubic_to(&tmp[0], normalAB, unitNormalAB, &norm, &unit, |
| 303 | subDivide); |
| 304 | // we use dummys since we already have a valid (and more accurate) |
| 305 | // normals for CD |
| 306 | this->cubic_to(&tmp[3], norm, unit, &dummy, &unitDummy, subDivide); |
| 307 | } else { |
| 308 | SkVector normalB, normalC; |
| 309 | |
| 310 | // need normals to inset/outset the off-curve pts B and C |
| 311 | |
| 312 | if (0) { // this is normal to the line between our adjacent pts |
| 313 | normalB = pts[2] - pts[0]; |
| 314 | normalB.rotateCCW(); |
| 315 | SkAssertResult(normalB.setLength(fRadius)); |
| 316 | |
| 317 | normalC = pts[3] - pts[1]; |
| 318 | normalC.rotateCCW(); |
| 319 | SkAssertResult(normalC.setLength(fRadius)); |
| 320 | } else { // miter-join |
| 321 | SkVector unitBC = pts[2] - pts[1]; |
| 322 | unitBC.normalize(); |
| 323 | unitBC.rotateCCW(); |
| 324 | |
| 325 | normalB = unitNormalAB + unitBC; |
| 326 | normalC = *unitNormalCD + unitBC; |
| 327 | |
| 328 | SkScalar dot = SkPoint::DotProduct(unitNormalAB, unitBC); |
| 329 | SkAssertResult(normalB.setLength(SkScalarDiv(fRadius, |
| 330 | SkScalarSqrt((SK_Scalar1 + dot)/2)))); |
| 331 | dot = SkPoint::DotProduct(*unitNormalCD, unitBC); |
| 332 | SkAssertResult(normalC.setLength(SkScalarDiv(fRadius, |
| 333 | SkScalarSqrt((SK_Scalar1 + dot)/2)))); |
| 334 | } |
| 335 | |
| 336 | fOuter.cubicTo( pts[1].fX + normalB.fX, pts[1].fY + normalB.fY, |
| 337 | pts[2].fX + normalC.fX, pts[2].fY + normalC.fY, |
| 338 | pts[3].fX + normalCD->fX, pts[3].fY + normalCD->fY); |
| 339 | |
| 340 | fInner.cubicTo( pts[1].fX - normalB.fX, pts[1].fY - normalB.fY, |
| 341 | pts[2].fX - normalC.fX, pts[2].fY - normalC.fY, |
| 342 | pts[3].fX - normalCD->fX, pts[3].fY - normalCD->fY); |
| 343 | } |
| 344 | } |
| 345 | |
| 346 | void SkPathStroker::quadTo(const SkPoint& pt1, const SkPoint& pt2) { |
schenney@chromium.org | 4da06ab | 2011-12-20 15:14:18 +0000 | [diff] [blame] | 347 | bool degenerateAB = SkPath::IsLineDegenerate(fPrevPt, pt1); |
| 348 | bool degenerateBC = SkPath::IsLineDegenerate(pt1, pt2); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 349 | |
| 350 | if (degenerateAB | degenerateBC) { |
| 351 | if (degenerateAB ^ degenerateBC) { |
| 352 | this->lineTo(pt2); |
| 353 | } |
| 354 | return; |
| 355 | } |
| 356 | |
| 357 | SkVector normalAB, unitAB, normalBC, unitBC; |
| 358 | |
| 359 | this->preJoinTo(pt1, &normalAB, &unitAB, false); |
| 360 | |
| 361 | { |
| 362 | SkPoint pts[3], tmp[5]; |
| 363 | pts[0] = fPrevPt; |
| 364 | pts[1] = pt1; |
| 365 | pts[2] = pt2; |
| 366 | |
| 367 | if (SkChopQuadAtMaxCurvature(pts, tmp) == 2) { |
| 368 | unitBC.setNormalize(pts[2].fX - pts[1].fX, pts[2].fY - pts[1].fY); |
| 369 | unitBC.rotateCCW(); |
| 370 | if (normals_too_pinchy(unitAB, unitBC)) { |
| 371 | normalBC = unitBC; |
| 372 | normalBC.scale(fRadius); |
| 373 | |
| 374 | fOuter.lineTo(tmp[2].fX + normalAB.fX, tmp[2].fY + normalAB.fY); |
| 375 | fOuter.lineTo(tmp[2].fX + normalBC.fX, tmp[2].fY + normalBC.fY); |
| 376 | fOuter.lineTo(tmp[4].fX + normalBC.fX, tmp[4].fY + normalBC.fY); |
| 377 | |
| 378 | fInner.lineTo(tmp[2].fX - normalAB.fX, tmp[2].fY - normalAB.fY); |
| 379 | fInner.lineTo(tmp[2].fX - normalBC.fX, tmp[2].fY - normalBC.fY); |
| 380 | fInner.lineTo(tmp[4].fX - normalBC.fX, tmp[4].fY - normalBC.fY); |
| 381 | |
| 382 | fExtra.addCircle(tmp[2].fX, tmp[2].fY, fRadius, |
| 383 | SkPath::kCW_Direction); |
| 384 | } else { |
| 385 | this->quad_to(&tmp[0], normalAB, unitAB, &normalBC, &unitBC, |
| 386 | kMaxQuadSubdivide); |
| 387 | SkVector n = normalBC; |
| 388 | SkVector u = unitBC; |
| 389 | this->quad_to(&tmp[2], n, u, &normalBC, &unitBC, |
| 390 | kMaxQuadSubdivide); |
| 391 | } |
| 392 | } else { |
| 393 | this->quad_to(pts, normalAB, unitAB, &normalBC, &unitBC, |
| 394 | kMaxQuadSubdivide); |
| 395 | } |
| 396 | } |
| 397 | |
| 398 | this->postJoinTo(pt2, normalBC, unitBC); |
| 399 | } |
| 400 | |
| 401 | void SkPathStroker::cubicTo(const SkPoint& pt1, const SkPoint& pt2, |
| 402 | const SkPoint& pt3) { |
schenney@chromium.org | 4da06ab | 2011-12-20 15:14:18 +0000 | [diff] [blame] | 403 | bool degenerateAB = SkPath::IsLineDegenerate(fPrevPt, pt1); |
| 404 | bool degenerateBC = SkPath::IsLineDegenerate(pt1, pt2); |
| 405 | bool degenerateCD = SkPath::IsLineDegenerate(pt2, pt3); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 406 | |
| 407 | if (degenerateAB + degenerateBC + degenerateCD >= 2) { |
| 408 | this->lineTo(pt3); |
| 409 | return; |
| 410 | } |
| 411 | |
| 412 | SkVector normalAB, unitAB, normalCD, unitCD; |
| 413 | |
| 414 | // find the first tangent (which might be pt1 or pt2 |
| 415 | { |
| 416 | const SkPoint* nextPt = &pt1; |
| 417 | if (degenerateAB) |
| 418 | nextPt = &pt2; |
| 419 | this->preJoinTo(*nextPt, &normalAB, &unitAB, false); |
| 420 | } |
| 421 | |
| 422 | { |
| 423 | SkPoint pts[4], tmp[13]; |
| 424 | int i, count; |
| 425 | SkVector n, u; |
| 426 | SkScalar tValues[3]; |
| 427 | |
| 428 | pts[0] = fPrevPt; |
| 429 | pts[1] = pt1; |
| 430 | pts[2] = pt2; |
| 431 | pts[3] = pt3; |
| 432 | |
| 433 | #if 1 |
| 434 | count = SkChopCubicAtMaxCurvature(pts, tmp, tValues); |
| 435 | #else |
| 436 | count = 1; |
| 437 | memcpy(tmp, pts, 4 * sizeof(SkPoint)); |
| 438 | #endif |
| 439 | n = normalAB; |
| 440 | u = unitAB; |
| 441 | for (i = 0; i < count; i++) { |
| 442 | this->cubic_to(&tmp[i * 3], n, u, &normalCD, &unitCD, |
| 443 | kMaxCubicSubdivide); |
| 444 | if (i == count - 1) { |
| 445 | break; |
| 446 | } |
| 447 | n = normalCD; |
| 448 | u = unitCD; |
| 449 | |
| 450 | } |
| 451 | |
| 452 | // check for too pinchy |
| 453 | for (i = 1; i < count; i++) { |
| 454 | SkPoint p; |
| 455 | SkVector v, c; |
| 456 | |
| 457 | SkEvalCubicAt(pts, tValues[i - 1], &p, &v, &c); |
| 458 | |
| 459 | SkScalar dot = SkPoint::DotProduct(c, c); |
| 460 | v.scale(SkScalarInvert(dot)); |
| 461 | |
| 462 | if (SkScalarNearlyZero(v.fX) && SkScalarNearlyZero(v.fY)) { |
| 463 | fExtra.addCircle(p.fX, p.fY, fRadius, SkPath::kCW_Direction); |
| 464 | } |
| 465 | } |
| 466 | |
| 467 | } |
| 468 | |
| 469 | this->postJoinTo(pt3, normalCD, unitCD); |
| 470 | } |
| 471 | |
| 472 | /////////////////////////////////////////////////////////////////////////////// |
| 473 | /////////////////////////////////////////////////////////////////////////////// |
| 474 | |
reed@google.com | aefdd06 | 2012-02-29 13:03:00 +0000 | [diff] [blame^] | 475 | #include "SkPaintDefaults.h" |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 476 | |
| 477 | SkStroke::SkStroke() { |
reed@google.com | aefdd06 | 2012-02-29 13:03:00 +0000 | [diff] [blame^] | 478 | fWidth = SK_Scalar1; |
| 479 | fMiterLimit = SkPaintDefaults_MiterLimit; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 480 | fCap = SkPaint::kDefault_Cap; |
| 481 | fJoin = SkPaint::kDefault_Join; |
| 482 | fDoFill = false; |
| 483 | } |
| 484 | |
| 485 | SkStroke::SkStroke(const SkPaint& p) { |
| 486 | fWidth = p.getStrokeWidth(); |
| 487 | fMiterLimit = p.getStrokeMiter(); |
| 488 | fCap = (uint8_t)p.getStrokeCap(); |
| 489 | fJoin = (uint8_t)p.getStrokeJoin(); |
| 490 | fDoFill = SkToU8(p.getStyle() == SkPaint::kStrokeAndFill_Style); |
| 491 | } |
| 492 | |
| 493 | SkStroke::SkStroke(const SkPaint& p, SkScalar width) { |
| 494 | fWidth = width; |
| 495 | fMiterLimit = p.getStrokeMiter(); |
| 496 | fCap = (uint8_t)p.getStrokeCap(); |
| 497 | fJoin = (uint8_t)p.getStrokeJoin(); |
| 498 | fDoFill = SkToU8(p.getStyle() == SkPaint::kStrokeAndFill_Style); |
| 499 | } |
| 500 | |
| 501 | void SkStroke::setWidth(SkScalar width) { |
| 502 | SkASSERT(width >= 0); |
| 503 | fWidth = width; |
| 504 | } |
| 505 | |
| 506 | void SkStroke::setMiterLimit(SkScalar miterLimit) { |
| 507 | SkASSERT(miterLimit >= 0); |
| 508 | fMiterLimit = miterLimit; |
| 509 | } |
| 510 | |
| 511 | void SkStroke::setCap(SkPaint::Cap cap) { |
| 512 | SkASSERT((unsigned)cap < SkPaint::kCapCount); |
| 513 | fCap = SkToU8(cap); |
| 514 | } |
| 515 | |
| 516 | void SkStroke::setJoin(SkPaint::Join join) { |
| 517 | SkASSERT((unsigned)join < SkPaint::kJoinCount); |
| 518 | fJoin = SkToU8(join); |
| 519 | } |
| 520 | |
| 521 | /////////////////////////////////////////////////////////////////////////////// |
| 522 | |
| 523 | #ifdef SK_SCALAR_IS_FIXED |
| 524 | /* return non-zero if the path is too big, and should be shrunk to avoid |
| 525 | overflows during intermediate calculations. Note that we compute the |
| 526 | bounds for this. If we had a custom callback/walker for paths, we could |
| 527 | perhaps go faster by using that, and just perform the abs | in that |
| 528 | routine |
| 529 | */ |
| 530 | static int needs_to_shrink(const SkPath& path) { |
reed@android.com | d252db0 | 2009-04-01 18:31:44 +0000 | [diff] [blame] | 531 | const SkRect& r = path.getBounds(); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 532 | SkFixed mask = SkAbs32(r.fLeft); |
| 533 | mask |= SkAbs32(r.fTop); |
| 534 | mask |= SkAbs32(r.fRight); |
| 535 | mask |= SkAbs32(r.fBottom); |
| 536 | // we need the top 3 bits clear (after abs) to avoid overflow |
| 537 | return mask >> 29; |
| 538 | } |
| 539 | |
| 540 | static void identity_proc(SkPoint pts[], int count) {} |
| 541 | static void shift_down_2_proc(SkPoint pts[], int count) { |
| 542 | for (int i = 0; i < count; i++) { |
| 543 | pts->fX >>= 2; |
| 544 | pts->fY >>= 2; |
| 545 | pts += 1; |
| 546 | } |
| 547 | } |
| 548 | #define APPLY_PROC(proc, pts, count) proc(pts, count) |
| 549 | #else // float does need any of this |
| 550 | #define APPLY_PROC(proc, pts, count) |
| 551 | #endif |
| 552 | |
| 553 | void SkStroke::strokePath(const SkPath& src, SkPath* dst) const { |
| 554 | SkASSERT(&src != NULL && dst != NULL); |
| 555 | |
| 556 | SkScalar radius = SkScalarHalf(fWidth); |
| 557 | |
| 558 | dst->reset(); |
| 559 | if (radius <= 0) { |
| 560 | return; |
| 561 | } |
| 562 | |
| 563 | #ifdef SK_SCALAR_IS_FIXED |
| 564 | void (*proc)(SkPoint pts[], int count) = identity_proc; |
| 565 | if (needs_to_shrink(src)) { |
| 566 | proc = shift_down_2_proc; |
| 567 | radius >>= 2; |
| 568 | if (radius == 0) { |
| 569 | return; |
| 570 | } |
| 571 | } |
| 572 | #endif |
| 573 | |
| 574 | SkPathStroker stroker(radius, fMiterLimit, this->getCap(), |
| 575 | this->getJoin()); |
| 576 | |
| 577 | SkPath::Iter iter(src, false); |
| 578 | SkPoint pts[4]; |
| 579 | SkPath::Verb verb, lastSegment = SkPath::kMove_Verb; |
| 580 | |
| 581 | while ((verb = iter.next(pts)) != SkPath::kDone_Verb) { |
| 582 | switch (verb) { |
| 583 | case SkPath::kMove_Verb: |
| 584 | APPLY_PROC(proc, &pts[0], 1); |
| 585 | stroker.moveTo(pts[0]); |
| 586 | break; |
| 587 | case SkPath::kLine_Verb: |
| 588 | APPLY_PROC(proc, &pts[1], 1); |
| 589 | stroker.lineTo(pts[1]); |
| 590 | lastSegment = verb; |
| 591 | break; |
| 592 | case SkPath::kQuad_Verb: |
| 593 | APPLY_PROC(proc, &pts[1], 2); |
| 594 | stroker.quadTo(pts[1], pts[2]); |
| 595 | lastSegment = verb; |
| 596 | break; |
| 597 | case SkPath::kCubic_Verb: |
| 598 | APPLY_PROC(proc, &pts[1], 3); |
| 599 | stroker.cubicTo(pts[1], pts[2], pts[3]); |
| 600 | lastSegment = verb; |
| 601 | break; |
| 602 | case SkPath::kClose_Verb: |
| 603 | stroker.close(lastSegment == SkPath::kLine_Verb); |
| 604 | break; |
| 605 | default: |
| 606 | break; |
| 607 | } |
| 608 | } |
| 609 | stroker.done(dst, lastSegment == SkPath::kLine_Verb); |
| 610 | |
| 611 | #ifdef SK_SCALAR_IS_FIXED |
| 612 | // undo our previous down_shift |
| 613 | if (shift_down_2_proc == proc) { |
| 614 | // need a real shift methid on path. antialias paths could use this too |
| 615 | SkMatrix matrix; |
| 616 | matrix.setScale(SkIntToScalar(4), SkIntToScalar(4)); |
| 617 | dst->transform(matrix); |
| 618 | } |
| 619 | #endif |
| 620 | |
| 621 | if (fDoFill) { |
reed@google.com | 1ae2090 | 2012-01-10 21:30:57 +0000 | [diff] [blame] | 622 | if (src.cheapIsDirection(SkPath::kCCW_Direction)) { |
reed@google.com | 69a9943 | 2012-01-10 18:00:10 +0000 | [diff] [blame] | 623 | dst->reverseAddPath(src); |
| 624 | } else { |
| 625 | dst->addPath(src); |
reed@google.com | 63d7374 | 2012-01-10 15:33:12 +0000 | [diff] [blame] | 626 | } |
reed@android.com | f2b98d6 | 2010-12-20 18:26:13 +0000 | [diff] [blame] | 627 | } else { |
reed@google.com | effe847 | 2011-10-31 12:55:49 +0000 | [diff] [blame] | 628 | // Seems like we can assume that a 2-point src would always result in |
| 629 | // a convex stroke, but testing has proved otherwise. |
| 630 | // TODO: fix the stroker to make this assumption true (without making |
| 631 | // it slower that the work that will be done in computeConvexity()) |
| 632 | #if 0 |
| 633 | // this test results in a non-convex stroke :( |
| 634 | static void test(SkCanvas* canvas) { |
| 635 | SkPoint pts[] = { 146.333328, 192.333328, 300.333344, 293.333344 }; |
| 636 | SkPaint paint; |
| 637 | paint.setStrokeWidth(7); |
| 638 | paint.setStrokeCap(SkPaint::kRound_Cap); |
| 639 | canvas->drawLine(pts[0].fX, pts[0].fY, pts[1].fX, pts[1].fY, paint); |
| 640 | } |
reed@google.com | 4d03c11 | 2011-10-31 12:12:12 +0000 | [diff] [blame] | 641 | #endif |
reed@google.com | effe847 | 2011-10-31 12:55:49 +0000 | [diff] [blame] | 642 | #if 0 |
| 643 | if (2 == src.countPoints()) { |
reed@android.com | f2b98d6 | 2010-12-20 18:26:13 +0000 | [diff] [blame] | 644 | dst->setIsConvex(true); |
| 645 | } |
reed@google.com | effe847 | 2011-10-31 12:55:49 +0000 | [diff] [blame] | 646 | #endif |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 647 | } |
reed@google.com | bb47232 | 2011-12-21 15:53:13 +0000 | [diff] [blame] | 648 | |
| 649 | // our answer should preserve the inverseness of the src |
| 650 | if (src.isInverseFillType()) { |
| 651 | SkASSERT(!dst->isInverseFillType()); |
| 652 | dst->toggleInverseFillType(); |
| 653 | } |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 654 | } |
| 655 | |
| 656 | void SkStroke::strokeLine(const SkPoint& p0, const SkPoint& p1, |
| 657 | SkPath* dst) const { |
| 658 | SkPath tmp; |
| 659 | |
| 660 | tmp.moveTo(p0); |
| 661 | tmp.lineTo(p1); |
| 662 | this->strokePath(tmp, dst); |
| 663 | } |
| 664 | |