1 /*
2 * Copyright 2013 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "SkBuffer.h"
9 #include "SkLazyPtr.h"
10 #include "SkPath.h"
11 #include "SkPathRef.h"
12
13 //////////////////////////////////////////////////////////////////////////////
Editor(SkAutoTUnref<SkPathRef> * pathRef,int incReserveVerbs,int incReservePoints)14 SkPathRef::Editor::Editor(SkAutoTUnref<SkPathRef>* pathRef,
15 int incReserveVerbs,
16 int incReservePoints)
17 {
18 if ((*pathRef)->unique()) {
19 (*pathRef)->incReserve(incReserveVerbs, incReservePoints);
20 } else {
21 SkPathRef* copy = SkNEW(SkPathRef);
22 copy->copy(**pathRef, incReserveVerbs, incReservePoints);
23 pathRef->reset(copy);
24 }
25 fPathRef = *pathRef;
26 fPathRef->fGenerationID = 0;
27 SkDEBUGCODE(sk_atomic_inc(&fPathRef->fEditorsAttached);)
28 }
29
30 //////////////////////////////////////////////////////////////////////////////
31
32 // As a template argument, this must have external linkage.
sk_create_empty_pathref()33 SkPathRef* sk_create_empty_pathref() {
34 SkPathRef* empty = SkNEW(SkPathRef);
35 empty->computeBounds(); // Avoids races later to be the first to do this.
36 return empty;
37 }
38
39 SK_DECLARE_STATIC_LAZY_PTR(SkPathRef, empty, sk_create_empty_pathref);
40
CreateEmpty()41 SkPathRef* SkPathRef::CreateEmpty() {
42 return SkRef(empty.get());
43 }
44
CreateTransformedCopy(SkAutoTUnref<SkPathRef> * dst,const SkPathRef & src,const SkMatrix & matrix)45 void SkPathRef::CreateTransformedCopy(SkAutoTUnref<SkPathRef>* dst,
46 const SkPathRef& src,
47 const SkMatrix& matrix) {
48 SkDEBUGCODE(src.validate();)
49 if (matrix.isIdentity()) {
50 if (*dst != &src) {
51 src.ref();
52 dst->reset(const_cast<SkPathRef*>(&src));
53 SkDEBUGCODE((*dst)->validate();)
54 }
55 return;
56 }
57
58 if (!(*dst)->unique()) {
59 dst->reset(SkNEW(SkPathRef));
60 }
61
62 if (*dst != &src) {
63 (*dst)->resetToSize(src.fVerbCnt, src.fPointCnt, src.fConicWeights.count());
64 memcpy((*dst)->verbsMemWritable(), src.verbsMemBegin(), src.fVerbCnt * sizeof(uint8_t));
65 (*dst)->fConicWeights = src.fConicWeights;
66 }
67
68 SkASSERT((*dst)->countPoints() == src.countPoints());
69 SkASSERT((*dst)->countVerbs() == src.countVerbs());
70 SkASSERT((*dst)->fConicWeights.count() == src.fConicWeights.count());
71
72 // Need to check this here in case (&src == dst)
73 bool canXformBounds = !src.fBoundsIsDirty && matrix.rectStaysRect() && src.countPoints() > 1;
74
75 matrix.mapPoints((*dst)->fPoints, src.points(), src.fPointCnt);
76
77 /*
78 * Here we optimize the bounds computation, by noting if the bounds are
79 * already known, and if so, we just transform those as well and mark
80 * them as "known", rather than force the transformed path to have to
81 * recompute them.
82 *
83 * Special gotchas if the path is effectively empty (<= 1 point) or
84 * if it is non-finite. In those cases bounds need to stay empty,
85 * regardless of the matrix.
86 */
87 if (canXformBounds) {
88 (*dst)->fBoundsIsDirty = false;
89 if (src.fIsFinite) {
90 matrix.mapRect(&(*dst)->fBounds, src.fBounds);
91 if (!((*dst)->fIsFinite = (*dst)->fBounds.isFinite())) {
92 (*dst)->fBounds.setEmpty();
93 }
94 } else {
95 (*dst)->fIsFinite = false;
96 (*dst)->fBounds.setEmpty();
97 }
98 } else {
99 (*dst)->fBoundsIsDirty = true;
100 }
101
102 (*dst)->fSegmentMask = src.fSegmentMask;
103
104 // It's an oval only if it stays a rect.
105 (*dst)->fIsOval = src.fIsOval && matrix.rectStaysRect();
106
107 SkDEBUGCODE((*dst)->validate();)
108 }
109
CreateFromBuffer(SkRBuffer * buffer)110 SkPathRef* SkPathRef::CreateFromBuffer(SkRBuffer* buffer) {
111 SkPathRef* ref = SkNEW(SkPathRef);
112 bool isOval;
113 uint8_t segmentMask;
114
115 int32_t packed;
116 if (!buffer->readS32(&packed)) {
117 SkDELETE(ref);
118 return NULL;
119 }
120
121 ref->fIsFinite = (packed >> kIsFinite_SerializationShift) & 1;
122 segmentMask = (packed >> kSegmentMask_SerializationShift) & 0xF;
123 isOval = (packed >> kIsOval_SerializationShift) & 1;
124
125 int32_t verbCount, pointCount, conicCount;
126 if (!buffer->readU32(&(ref->fGenerationID)) ||
127 !buffer->readS32(&verbCount) ||
128 !buffer->readS32(&pointCount) ||
129 !buffer->readS32(&conicCount)) {
130 SkDELETE(ref);
131 return NULL;
132 }
133
134 ref->resetToSize(verbCount, pointCount, conicCount);
135 SkASSERT(verbCount == ref->countVerbs());
136 SkASSERT(pointCount == ref->countPoints());
137 SkASSERT(conicCount == ref->fConicWeights.count());
138
139 if (!buffer->read(ref->verbsMemWritable(), verbCount * sizeof(uint8_t)) ||
140 !buffer->read(ref->fPoints, pointCount * sizeof(SkPoint)) ||
141 !buffer->read(ref->fConicWeights.begin(), conicCount * sizeof(SkScalar)) ||
142 !buffer->read(&ref->fBounds, sizeof(SkRect))) {
143 SkDELETE(ref);
144 return NULL;
145 }
146 ref->fBoundsIsDirty = false;
147
148 // resetToSize clears fSegmentMask and fIsOval
149 ref->fSegmentMask = segmentMask;
150 ref->fIsOval = isOval;
151 return ref;
152 }
153
Rewind(SkAutoTUnref<SkPathRef> * pathRef)154 void SkPathRef::Rewind(SkAutoTUnref<SkPathRef>* pathRef) {
155 if ((*pathRef)->unique()) {
156 SkDEBUGCODE((*pathRef)->validate();)
157 (*pathRef)->fBoundsIsDirty = true; // this also invalidates fIsFinite
158 (*pathRef)->fVerbCnt = 0;
159 (*pathRef)->fPointCnt = 0;
160 (*pathRef)->fFreeSpace = (*pathRef)->currSize();
161 (*pathRef)->fGenerationID = 0;
162 (*pathRef)->fConicWeights.rewind();
163 (*pathRef)->fSegmentMask = 0;
164 (*pathRef)->fIsOval = false;
165 SkDEBUGCODE((*pathRef)->validate();)
166 } else {
167 int oldVCnt = (*pathRef)->countVerbs();
168 int oldPCnt = (*pathRef)->countPoints();
169 pathRef->reset(SkNEW(SkPathRef));
170 (*pathRef)->resetToSize(0, 0, 0, oldVCnt, oldPCnt);
171 }
172 }
173
operator ==(const SkPathRef & ref) const174 bool SkPathRef::operator== (const SkPathRef& ref) const {
175 SkDEBUGCODE(this->validate();)
176 SkDEBUGCODE(ref.validate();)
177
178 // We explicitly check fSegmentMask as a quick-reject. We could skip it,
179 // since it is only a cache of info in the fVerbs, but its a fast way to
180 // notice a difference
181 if (fSegmentMask != ref.fSegmentMask) {
182 return false;
183 }
184
185 bool genIDMatch = fGenerationID && fGenerationID == ref.fGenerationID;
186 #ifdef SK_RELEASE
187 if (genIDMatch) {
188 return true;
189 }
190 #endif
191 if (fPointCnt != ref.fPointCnt ||
192 fVerbCnt != ref.fVerbCnt) {
193 SkASSERT(!genIDMatch);
194 return false;
195 }
196 if (0 == ref.fVerbCnt) {
197 SkASSERT(0 == ref.fPointCnt);
198 return true;
199 }
200 SkASSERT(this->verbsMemBegin() && ref.verbsMemBegin());
201 if (0 != memcmp(this->verbsMemBegin(),
202 ref.verbsMemBegin(),
203 ref.fVerbCnt * sizeof(uint8_t))) {
204 SkASSERT(!genIDMatch);
205 return false;
206 }
207 SkASSERT(this->points() && ref.points());
208 if (0 != memcmp(this->points(),
209 ref.points(),
210 ref.fPointCnt * sizeof(SkPoint))) {
211 SkASSERT(!genIDMatch);
212 return false;
213 }
214 if (fConicWeights != ref.fConicWeights) {
215 SkASSERT(!genIDMatch);
216 return false;
217 }
218 // We've done the work to determine that these are equal. If either has a zero genID, copy
219 // the other's. If both are 0 then genID() will compute the next ID.
220 if (0 == fGenerationID) {
221 fGenerationID = ref.genID();
222 } else if (0 == ref.fGenerationID) {
223 ref.fGenerationID = this->genID();
224 }
225 return true;
226 }
227
writeToBuffer(SkWBuffer * buffer) const228 void SkPathRef::writeToBuffer(SkWBuffer* buffer) const {
229 SkDEBUGCODE(this->validate();)
230 SkDEBUGCODE(size_t beforePos = buffer->pos();)
231
232 // Call getBounds() to ensure (as a side-effect) that fBounds
233 // and fIsFinite are computed.
234 const SkRect& bounds = this->getBounds();
235
236 int32_t packed = ((fIsFinite & 1) << kIsFinite_SerializationShift) |
237 ((fIsOval & 1) << kIsOval_SerializationShift) |
238 (fSegmentMask << kSegmentMask_SerializationShift);
239 buffer->write32(packed);
240
241 // TODO: write gen ID here. Problem: We don't know if we're cross process or not from
242 // SkWBuffer. Until this is fixed we write 0.
243 buffer->write32(0);
244 buffer->write32(fVerbCnt);
245 buffer->write32(fPointCnt);
246 buffer->write32(fConicWeights.count());
247 buffer->write(verbsMemBegin(), fVerbCnt * sizeof(uint8_t));
248 buffer->write(fPoints, fPointCnt * sizeof(SkPoint));
249 buffer->write(fConicWeights.begin(), fConicWeights.bytes());
250 buffer->write(&bounds, sizeof(bounds));
251
252 SkASSERT(buffer->pos() - beforePos == (size_t) this->writeSize());
253 }
254
writeSize() const255 uint32_t SkPathRef::writeSize() const {
256 return uint32_t(5 * sizeof(uint32_t) +
257 fVerbCnt * sizeof(uint8_t) +
258 fPointCnt * sizeof(SkPoint) +
259 fConicWeights.bytes() +
260 sizeof(SkRect));
261 }
262
copy(const SkPathRef & ref,int additionalReserveVerbs,int additionalReservePoints)263 void SkPathRef::copy(const SkPathRef& ref,
264 int additionalReserveVerbs,
265 int additionalReservePoints) {
266 SkDEBUGCODE(this->validate();)
267 this->resetToSize(ref.fVerbCnt, ref.fPointCnt, ref.fConicWeights.count(),
268 additionalReserveVerbs, additionalReservePoints);
269 memcpy(this->verbsMemWritable(), ref.verbsMemBegin(), ref.fVerbCnt * sizeof(uint8_t));
270 memcpy(this->fPoints, ref.fPoints, ref.fPointCnt * sizeof(SkPoint));
271 fConicWeights = ref.fConicWeights;
272 // We could call genID() here to force a real ID (instead of 0). However, if we're making
273 // a copy then presumably we intend to make a modification immediately afterwards.
274 fGenerationID = ref.fGenerationID;
275 fBoundsIsDirty = ref.fBoundsIsDirty;
276 if (!fBoundsIsDirty) {
277 fBounds = ref.fBounds;
278 fIsFinite = ref.fIsFinite;
279 }
280 fSegmentMask = ref.fSegmentMask;
281 fIsOval = ref.fIsOval;
282 SkDEBUGCODE(this->validate();)
283 }
284
growForRepeatedVerb(int verb,int numVbs,SkScalar ** weights)285 SkPoint* SkPathRef::growForRepeatedVerb(int /*SkPath::Verb*/ verb,
286 int numVbs,
287 SkScalar** weights) {
288 // This value is just made-up for now. When count is 4, calling memset was much
289 // slower than just writing the loop. This seems odd, and hopefully in the
290 // future this will appear to have been a fluke...
291 static const unsigned int kMIN_COUNT_FOR_MEMSET_TO_BE_FAST = 16;
292
293 SkDEBUGCODE(this->validate();)
294 int pCnt;
295 bool dirtyAfterEdit = true;
296 switch (verb) {
297 case SkPath::kMove_Verb:
298 pCnt = numVbs;
299 dirtyAfterEdit = false;
300 break;
301 case SkPath::kLine_Verb:
302 fSegmentMask |= SkPath::kLine_SegmentMask;
303 pCnt = numVbs;
304 break;
305 case SkPath::kQuad_Verb:
306 fSegmentMask |= SkPath::kQuad_SegmentMask;
307 pCnt = 2 * numVbs;
308 break;
309 case SkPath::kConic_Verb:
310 fSegmentMask |= SkPath::kConic_SegmentMask;
311 pCnt = 2 * numVbs;
312 break;
313 case SkPath::kCubic_Verb:
314 fSegmentMask |= SkPath::kCubic_SegmentMask;
315 pCnt = 3 * numVbs;
316 break;
317 case SkPath::kClose_Verb:
318 SkDEBUGFAIL("growForRepeatedVerb called for kClose_Verb");
319 pCnt = 0;
320 dirtyAfterEdit = false;
321 break;
322 case SkPath::kDone_Verb:
323 SkDEBUGFAIL("growForRepeatedVerb called for kDone");
324 // fall through
325 default:
326 SkDEBUGFAIL("default should not be reached");
327 pCnt = 0;
328 dirtyAfterEdit = false;
329 }
330
331 size_t space = numVbs * sizeof(uint8_t) + pCnt * sizeof (SkPoint);
332 this->makeSpace(space);
333
334 SkPoint* ret = fPoints + fPointCnt;
335 uint8_t* vb = fVerbs - fVerbCnt;
336
337 // cast to unsigned, so if kMIN_COUNT_FOR_MEMSET_TO_BE_FAST is defined to
338 // be 0, the compiler will remove the test/branch entirely.
339 if ((unsigned)numVbs >= kMIN_COUNT_FOR_MEMSET_TO_BE_FAST) {
340 memset(vb - numVbs, verb, numVbs);
341 } else {
342 for (int i = 0; i < numVbs; ++i) {
343 vb[~i] = verb;
344 }
345 }
346
347 fVerbCnt += numVbs;
348 fPointCnt += pCnt;
349 fFreeSpace -= space;
350 fBoundsIsDirty = true; // this also invalidates fIsFinite
351 if (dirtyAfterEdit) {
352 fIsOval = false;
353 }
354
355 if (SkPath::kConic_Verb == verb) {
356 SkASSERT(weights);
357 *weights = fConicWeights.append(numVbs);
358 }
359
360 SkDEBUGCODE(this->validate();)
361 return ret;
362 }
363
growForVerb(int verb,SkScalar weight)364 SkPoint* SkPathRef::growForVerb(int /* SkPath::Verb*/ verb, SkScalar weight) {
365 SkDEBUGCODE(this->validate();)
366 int pCnt;
367 bool dirtyAfterEdit = true;
368 switch (verb) {
369 case SkPath::kMove_Verb:
370 pCnt = 1;
371 dirtyAfterEdit = false;
372 break;
373 case SkPath::kLine_Verb:
374 fSegmentMask |= SkPath::kLine_SegmentMask;
375 pCnt = 1;
376 break;
377 case SkPath::kQuad_Verb:
378 fSegmentMask |= SkPath::kQuad_SegmentMask;
379 pCnt = 2;
380 break;
381 case SkPath::kConic_Verb:
382 fSegmentMask |= SkPath::kConic_SegmentMask;
383 pCnt = 2;
384 break;
385 case SkPath::kCubic_Verb:
386 fSegmentMask |= SkPath::kCubic_SegmentMask;
387 pCnt = 3;
388 break;
389 case SkPath::kClose_Verb:
390 pCnt = 0;
391 dirtyAfterEdit = false;
392 break;
393 case SkPath::kDone_Verb:
394 SkDEBUGFAIL("growForVerb called for kDone");
395 // fall through
396 default:
397 SkDEBUGFAIL("default is not reached");
398 dirtyAfterEdit = false;
399 pCnt = 0;
400 }
401 size_t space = sizeof(uint8_t) + pCnt * sizeof (SkPoint);
402 this->makeSpace(space);
403 this->fVerbs[~fVerbCnt] = verb;
404 SkPoint* ret = fPoints + fPointCnt;
405 fVerbCnt += 1;
406 fPointCnt += pCnt;
407 fFreeSpace -= space;
408 fBoundsIsDirty = true; // this also invalidates fIsFinite
409 if (dirtyAfterEdit) {
410 fIsOval = false;
411 }
412
413 if (SkPath::kConic_Verb == verb) {
414 *fConicWeights.append() = weight;
415 }
416
417 SkDEBUGCODE(this->validate();)
418 return ret;
419 }
420
genID() const421 uint32_t SkPathRef::genID() const {
422 SkASSERT(!fEditorsAttached);
423 static const uint32_t kMask = (static_cast<int64_t>(1) << SkPath::kPathRefGenIDBitCnt) - 1;
424 if (!fGenerationID) {
425 if (0 == fPointCnt && 0 == fVerbCnt) {
426 fGenerationID = kEmptyGenID;
427 } else {
428 static int32_t gPathRefGenerationID;
429 // do a loop in case our global wraps around, as we never want to return a 0 or the
430 // empty ID
431 do {
432 fGenerationID = (sk_atomic_inc(&gPathRefGenerationID) + 1) & kMask;
433 } while (fGenerationID <= kEmptyGenID);
434 }
435 }
436 return fGenerationID;
437 }
438
439 #ifdef SK_DEBUG
validate() const440 void SkPathRef::validate() const {
441 this->INHERITED::validate();
442 SkASSERT(static_cast<ptrdiff_t>(fFreeSpace) >= 0);
443 SkASSERT(reinterpret_cast<intptr_t>(fVerbs) - reinterpret_cast<intptr_t>(fPoints) >= 0);
444 SkASSERT((NULL == fPoints) == (NULL == fVerbs));
445 SkASSERT(!(NULL == fPoints && 0 != fFreeSpace));
446 SkASSERT(!(NULL == fPoints && 0 != fFreeSpace));
447 SkASSERT(!(NULL == fPoints && fPointCnt));
448 SkASSERT(!(NULL == fVerbs && fVerbCnt));
449 SkASSERT(this->currSize() ==
450 fFreeSpace + sizeof(SkPoint) * fPointCnt + sizeof(uint8_t) * fVerbCnt);
451
452 if (!fBoundsIsDirty && !fBounds.isEmpty()) {
453 bool isFinite = true;
454 for (int i = 0; i < fPointCnt; ++i) {
455 #ifdef SK_DEBUG
456 if (fPoints[i].isFinite() &&
457 (fPoints[i].fX < fBounds.fLeft || fPoints[i].fX > fBounds.fRight ||
458 fPoints[i].fY < fBounds.fTop || fPoints[i].fY > fBounds.fBottom)) {
459 SkDebugf("bounds: %f %f %f %f\n",
460 fBounds.fLeft, fBounds.fTop, fBounds.fRight, fBounds.fBottom);
461 for (int j = 0; j < fPointCnt; ++j) {
462 if (i == j) {
463 SkDebugf("*");
464 }
465 SkDebugf("%f %f\n", fPoints[j].fX, fPoints[j].fY);
466 }
467 }
468 #endif
469
470 SkASSERT(!fPoints[i].isFinite() ||
471 (fPoints[i].fX >= fBounds.fLeft && fPoints[i].fX <= fBounds.fRight &&
472 fPoints[i].fY >= fBounds.fTop && fPoints[i].fY <= fBounds.fBottom));
473 if (!fPoints[i].isFinite()) {
474 isFinite = false;
475 }
476 }
477 SkASSERT(SkToBool(fIsFinite) == isFinite);
478 }
479
480 #ifdef SK_DEBUG_PATH
481 uint32_t mask = 0;
482 for (int i = 0; i < fVerbCnt; ++i) {
483 switch (fVerbs[~i]) {
484 case SkPath::kMove_Verb:
485 break;
486 case SkPath::kLine_Verb:
487 mask |= SkPath::kLine_SegmentMask;
488 break;
489 case SkPath::kQuad_Verb:
490 mask |= SkPath::kQuad_SegmentMask;
491 break;
492 case SkPath::kConic_Verb:
493 mask |= SkPath::kConic_SegmentMask;
494 break;
495 case SkPath::kCubic_Verb:
496 mask |= SkPath::kCubic_SegmentMask;
497 break;
498 case SkPath::kClose_Verb:
499 break;
500 case SkPath::kDone_Verb:
501 SkDEBUGFAIL("Done verb shouldn't be recorded.");
502 break;
503 default:
504 SkDEBUGFAIL("Unknown Verb");
505 break;
506 }
507 }
508 SkASSERT(mask == fSegmentMask);
509 #endif // SK_DEBUG_PATH
510 }
511 #endif
512