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      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 "SkNx.h"
     10 #include "SkOnce.h"
     11 #include "SkPath.h"
     12 #include "SkPathRef.h"
     13 #include "SkPathPriv.h"
     14 #include "SkSafeMath.h"
     15 
     16 // Conic weights must be 0 < weight <= finite
     17 static bool validate_conic_weights(const SkScalar weights[], int count) {
     18     for (int i = 0; i < count; ++i) {
     19         if (weights[i] <= 0 || !SkScalarIsFinite(weights[i])) {
     20             return false;
     21         }
     22     }
     23     return true;
     24 }
     25 
     26 //////////////////////////////////////////////////////////////////////////////
     27 SkPathRef::Editor::Editor(sk_sp<SkPathRef>* pathRef,
     28                           int incReserveVerbs,
     29                           int incReservePoints)
     30 {
     31     if ((*pathRef)->unique()) {
     32         (*pathRef)->incReserve(incReserveVerbs, incReservePoints);
     33     } else {
     34         SkPathRef* copy = new SkPathRef;
     35         copy->copy(**pathRef, incReserveVerbs, incReservePoints);
     36         pathRef->reset(copy);
     37     }
     38     fPathRef = pathRef->get();
     39     fPathRef->callGenIDChangeListeners();
     40     fPathRef->fGenerationID = 0;
     41     SkDEBUGCODE(sk_atomic_inc(&fPathRef->fEditorsAttached);)
     42 }
     43 
     44 //////////////////////////////////////////////////////////////////////////////
     45 
     46 SkPathRef::~SkPathRef() {
     47     // Deliberately don't validate() this path ref, otherwise there's no way
     48     // to read one that's not valid and then free its memory without asserting.
     49     this->callGenIDChangeListeners();
     50     sk_free(fPoints);
     51 
     52     SkDEBUGCODE(fPoints = nullptr;)
     53     SkDEBUGCODE(fVerbs = nullptr;)
     54     SkDEBUGCODE(fVerbCnt = 0x9999999;)
     55     SkDEBUGCODE(fPointCnt = 0xAAAAAAA;)
     56     SkDEBUGCODE(fPointCnt = 0xBBBBBBB;)
     57     SkDEBUGCODE(fGenerationID = 0xEEEEEEEE;)
     58     SkDEBUGCODE(fEditorsAttached = 0x7777777;)
     59 }
     60 
     61 static SkPathRef* gEmpty = nullptr;
     62 
     63 SkPathRef* SkPathRef::CreateEmpty() {
     64     static SkOnce once;
     65     once([]{
     66         gEmpty = new SkPathRef;
     67         gEmpty->computeBounds();   // Avoids races later to be the first to do this.
     68     });
     69     return SkRef(gEmpty);
     70 }
     71 
     72 static void transform_dir_and_start(const SkMatrix& matrix, bool isRRect, bool* isCCW,
     73                                     unsigned* start) {
     74     int inStart = *start;
     75     int rm = 0;
     76     if (isRRect) {
     77         // Degenerate rrect indices to oval indices and remember the remainder.
     78         // Ovals have one index per side whereas rrects have two.
     79         rm = inStart & 0b1;
     80         inStart /= 2;
     81     }
     82     // Is the antidiagonal non-zero (otherwise the diagonal is zero)
     83     int antiDiag;
     84     // Is the non-zero value in the top row (either kMScaleX or kMSkewX) negative
     85     int topNeg;
     86     // Are the two non-zero diagonal or antidiagonal values the same sign.
     87     int sameSign;
     88     if (matrix.get(SkMatrix::kMScaleX) != 0) {
     89         antiDiag = 0b00;
     90         if (matrix.get(SkMatrix::kMScaleX) > 0) {
     91             topNeg = 0b00;
     92             sameSign = matrix.get(SkMatrix::kMScaleY) > 0 ? 0b01 : 0b00;
     93         } else {
     94             topNeg = 0b10;
     95             sameSign = matrix.get(SkMatrix::kMScaleY) > 0 ? 0b00 : 0b01;
     96         }
     97     } else {
     98         antiDiag = 0b01;
     99         if (matrix.get(SkMatrix::kMSkewX) > 0) {
    100             topNeg = 0b00;
    101             sameSign = matrix.get(SkMatrix::kMSkewY) > 0 ? 0b01 : 0b00;
    102         } else {
    103             topNeg = 0b10;
    104             sameSign = matrix.get(SkMatrix::kMSkewY) > 0 ? 0b00 : 0b01;
    105         }
    106     }
    107     if (sameSign != antiDiag) {
    108         // This is a rotation (and maybe scale). The direction is unchanged.
    109         // Trust me on the start computation (or draw yourself some pictures)
    110         *start = (inStart + 4 - (topNeg | antiDiag)) % 4;
    111         SkASSERT(*start < 4);
    112         if (isRRect) {
    113             *start = 2 * *start + rm;
    114         }
    115     } else {
    116         // This is a mirror (and maybe scale). The direction is reversed.
    117         *isCCW = !*isCCW;
    118         // Trust me on the start computation (or draw yourself some pictures)
    119         *start = (6 + (topNeg | antiDiag) - inStart) % 4;
    120         SkASSERT(*start < 4);
    121         if (isRRect) {
    122             *start = 2 * *start + (rm ? 0 : 1);
    123         }
    124     }
    125 }
    126 
    127 void SkPathRef::CreateTransformedCopy(sk_sp<SkPathRef>* dst,
    128                                       const SkPathRef& src,
    129                                       const SkMatrix& matrix) {
    130     SkDEBUGCODE(src.validate();)
    131     if (matrix.isIdentity()) {
    132         if (dst->get() != &src) {
    133             src.ref();
    134             dst->reset(const_cast<SkPathRef*>(&src));
    135             SkDEBUGCODE((*dst)->validate();)
    136         }
    137         return;
    138     }
    139 
    140     if (!(*dst)->unique()) {
    141         dst->reset(new SkPathRef);
    142     }
    143 
    144     if (dst->get() != &src) {
    145         (*dst)->resetToSize(src.fVerbCnt, src.fPointCnt, src.fConicWeights.count());
    146         sk_careful_memcpy((*dst)->verbsMemWritable(), src.verbsMemBegin(),
    147                            src.fVerbCnt * sizeof(uint8_t));
    148         (*dst)->fConicWeights = src.fConicWeights;
    149     }
    150 
    151     SkASSERT((*dst)->countPoints() == src.countPoints());
    152     SkASSERT((*dst)->countVerbs() == src.countVerbs());
    153     SkASSERT((*dst)->fConicWeights.count() == src.fConicWeights.count());
    154 
    155     // Need to check this here in case (&src == dst)
    156     bool canXformBounds = !src.fBoundsIsDirty && matrix.rectStaysRect() && src.countPoints() > 1;
    157 
    158     matrix.mapPoints((*dst)->fPoints, src.points(), src.fPointCnt);
    159 
    160     /*
    161      *  Here we optimize the bounds computation, by noting if the bounds are
    162      *  already known, and if so, we just transform those as well and mark
    163      *  them as "known", rather than force the transformed path to have to
    164      *  recompute them.
    165      *
    166      *  Special gotchas if the path is effectively empty (<= 1 point) or
    167      *  if it is non-finite. In those cases bounds need to stay empty,
    168      *  regardless of the matrix.
    169      */
    170     if (canXformBounds) {
    171         (*dst)->fBoundsIsDirty = false;
    172         if (src.fIsFinite) {
    173             matrix.mapRect(&(*dst)->fBounds, src.fBounds);
    174             if (!((*dst)->fIsFinite = (*dst)->fBounds.isFinite())) {
    175                 (*dst)->fBounds.setEmpty();
    176             }
    177         } else {
    178             (*dst)->fIsFinite = false;
    179             (*dst)->fBounds.setEmpty();
    180         }
    181     } else {
    182         (*dst)->fBoundsIsDirty = true;
    183     }
    184 
    185     (*dst)->fSegmentMask = src.fSegmentMask;
    186 
    187     // It's an oval only if it stays a rect.
    188     bool rectStaysRect = matrix.rectStaysRect();
    189     (*dst)->fIsOval = src.fIsOval && rectStaysRect;
    190     (*dst)->fIsRRect = src.fIsRRect && rectStaysRect;
    191     if ((*dst)->fIsOval || (*dst)->fIsRRect) {
    192         unsigned start = src.fRRectOrOvalStartIdx;
    193         bool isCCW = SkToBool(src.fRRectOrOvalIsCCW);
    194         transform_dir_and_start(matrix, (*dst)->fIsRRect, &isCCW, &start);
    195         (*dst)->fRRectOrOvalIsCCW = isCCW;
    196         (*dst)->fRRectOrOvalStartIdx = start;
    197     }
    198 
    199     SkDEBUGCODE((*dst)->validate();)
    200 }
    201 
    202 static bool validate_verb_sequence(const uint8_t verbs[], int vCount) {
    203     // verbs are stored backwards, but we need to visit them in logical order to determine if
    204     // they form a valid sequence.
    205 
    206     bool needsMoveTo = true;
    207     bool invalidSequence = false;
    208 
    209     for (int i = vCount - 1; i >= 0; --i) {
    210         switch (verbs[i]) {
    211             case SkPath::kMove_Verb:
    212                 needsMoveTo = false;
    213                 break;
    214             case SkPath::kLine_Verb:
    215             case SkPath::kQuad_Verb:
    216             case SkPath::kConic_Verb:
    217             case SkPath::kCubic_Verb:
    218                 invalidSequence |= needsMoveTo;
    219                 break;
    220             case SkPath::kClose_Verb:
    221                 needsMoveTo = true;
    222                 break;
    223             default:
    224                 return false;   // unknown verb
    225         }
    226     }
    227     return !invalidSequence;
    228 }
    229 
    230 // Given the verb array, deduce the required number of pts and conics,
    231 // or if an invalid verb is encountered, return false.
    232 static bool deduce_pts_conics(const uint8_t verbs[], int vCount, int* ptCountPtr,
    233                               int* conicCountPtr) {
    234     // When there is at least one verb, the first is required to be kMove_Verb.
    235     if (0 < vCount && verbs[vCount-1] != SkPath::kMove_Verb) {
    236         return false;
    237     }
    238 
    239     SkSafeMath safe;
    240     int ptCount = 0;
    241     int conicCount = 0;
    242     for (int i = 0; i < vCount; ++i) {
    243         switch (verbs[i]) {
    244             case SkPath::kMove_Verb:
    245             case SkPath::kLine_Verb:
    246                 ptCount = safe.addInt(ptCount, 1);
    247                 break;
    248             case SkPath::kConic_Verb:
    249                 conicCount += 1;
    250                 // fall-through
    251             case SkPath::kQuad_Verb:
    252                 ptCount = safe.addInt(ptCount, 2);
    253                 break;
    254             case SkPath::kCubic_Verb:
    255                 ptCount = safe.addInt(ptCount, 3);
    256                 break;
    257             case SkPath::kClose_Verb:
    258                 break;
    259             default:
    260                 return false;
    261         }
    262     }
    263     if (!safe) {
    264         return false;
    265     }
    266     *ptCountPtr = ptCount;
    267     *conicCountPtr = conicCount;
    268     return true;
    269 }
    270 
    271 SkPathRef* SkPathRef::CreateFromBuffer(SkRBuffer* buffer) {
    272     std::unique_ptr<SkPathRef> ref(new SkPathRef);
    273 
    274     int32_t packed;
    275     if (!buffer->readS32(&packed)) {
    276         return nullptr;
    277     }
    278 
    279     ref->fIsFinite = (packed >> kIsFinite_SerializationShift) & 1;
    280     uint8_t segmentMask = (packed >> kSegmentMask_SerializationShift) & 0xF;
    281 
    282     int32_t verbCount, pointCount, conicCount;
    283     if (!buffer->readU32(&(ref->fGenerationID)) ||
    284         !buffer->readS32(&verbCount)            || (verbCount  < 0) ||
    285         !buffer->readS32(&pointCount)           || (pointCount < 0) ||
    286         !buffer->readS32(&conicCount)           || (conicCount < 0))
    287     {
    288         return nullptr;
    289     }
    290 
    291     uint64_t pointSize64 = sk_64_mul(pointCount, sizeof(SkPoint));
    292     uint64_t conicSize64 = sk_64_mul(conicCount, sizeof(SkScalar));
    293     if (!SkTFitsIn<size_t>(pointSize64) || !SkTFitsIn<size_t>(conicSize64)) {
    294         return nullptr;
    295     }
    296 
    297     size_t verbSize = verbCount * sizeof(uint8_t);
    298     size_t pointSize = SkToSizeT(pointSize64);
    299     size_t conicSize = SkToSizeT(conicSize64);
    300 
    301     {
    302         uint64_t requiredBufferSize = sizeof(SkRect);
    303         requiredBufferSize += verbSize;
    304         requiredBufferSize += pointSize;
    305         requiredBufferSize += conicSize;
    306         if (buffer->available() < requiredBufferSize) {
    307             return nullptr;
    308         }
    309     }
    310 
    311     ref->resetToSize(verbCount, pointCount, conicCount);
    312     SkASSERT(verbCount  == ref->countVerbs());
    313     SkASSERT(pointCount == ref->countPoints());
    314     SkASSERT(conicCount == ref->fConicWeights.count());
    315 
    316     if (!buffer->read(ref->verbsMemWritable(), verbSize) ||
    317         !buffer->read(ref->fPoints, pointSize) ||
    318         !buffer->read(ref->fConicWeights.begin(), conicSize) ||
    319         !buffer->read(&ref->fBounds, sizeof(SkRect))) {
    320         return nullptr;
    321     }
    322 
    323     // Check that the verbs are valid, and imply the correct number of pts and conics
    324     {
    325         int pCount, cCount;
    326         if (!validate_verb_sequence(ref->verbsMemBegin(), ref->countVerbs())) {
    327             return nullptr;
    328         }
    329         if (!deduce_pts_conics(ref->verbsMemBegin(), ref->countVerbs(), &pCount, &cCount) ||
    330             pCount != ref->countPoints() || cCount != ref->fConicWeights.count()) {
    331             return nullptr;
    332         }
    333         if (!validate_conic_weights(ref->fConicWeights.begin(), ref->fConicWeights.count())) {
    334             return nullptr;
    335         }
    336         // Check that the bounds match the serialized bounds.
    337         SkRect bounds;
    338         if (ComputePtBounds(&bounds, *ref) != SkToBool(ref->fIsFinite) || bounds != ref->fBounds) {
    339             return nullptr;
    340         }
    341     }
    342 
    343     ref->fBoundsIsDirty = false;
    344 
    345     // resetToSize clears fSegmentMask and fIsOval
    346     ref->fSegmentMask = segmentMask;
    347     return ref.release();
    348 }
    349 
    350 void SkPathRef::Rewind(sk_sp<SkPathRef>* pathRef) {
    351     if ((*pathRef)->unique()) {
    352         SkDEBUGCODE((*pathRef)->validate();)
    353         (*pathRef)->callGenIDChangeListeners();
    354         (*pathRef)->fBoundsIsDirty = true;  // this also invalidates fIsFinite
    355         (*pathRef)->fVerbCnt = 0;
    356         (*pathRef)->fPointCnt = 0;
    357         (*pathRef)->fFreeSpace = (*pathRef)->currSize();
    358         (*pathRef)->fGenerationID = 0;
    359         (*pathRef)->fConicWeights.rewind();
    360         (*pathRef)->fSegmentMask = 0;
    361         (*pathRef)->fIsOval = false;
    362         (*pathRef)->fIsRRect = false;
    363         SkDEBUGCODE((*pathRef)->validate();)
    364     } else {
    365         int oldVCnt = (*pathRef)->countVerbs();
    366         int oldPCnt = (*pathRef)->countPoints();
    367         pathRef->reset(new SkPathRef);
    368         (*pathRef)->resetToSize(0, 0, 0, oldVCnt, oldPCnt);
    369     }
    370 }
    371 
    372 bool SkPathRef::operator== (const SkPathRef& ref) const {
    373     SkDEBUGCODE(this->validate();)
    374     SkDEBUGCODE(ref.validate();)
    375 
    376     // We explicitly check fSegmentMask as a quick-reject. We could skip it,
    377     // since it is only a cache of info in the fVerbs, but its a fast way to
    378     // notice a difference
    379     if (fSegmentMask != ref.fSegmentMask) {
    380         return false;
    381     }
    382 
    383     bool genIDMatch = fGenerationID && fGenerationID == ref.fGenerationID;
    384 #ifdef SK_RELEASE
    385     if (genIDMatch) {
    386         return true;
    387     }
    388 #endif
    389     if (fPointCnt != ref.fPointCnt ||
    390         fVerbCnt != ref.fVerbCnt) {
    391         SkASSERT(!genIDMatch);
    392         return false;
    393     }
    394     if (0 == ref.fVerbCnt) {
    395         SkASSERT(0 == ref.fPointCnt);
    396         return true;
    397     }
    398     SkASSERT(this->verbsMemBegin() && ref.verbsMemBegin());
    399     if (0 != memcmp(this->verbsMemBegin(),
    400                     ref.verbsMemBegin(),
    401                     ref.fVerbCnt * sizeof(uint8_t))) {
    402         SkASSERT(!genIDMatch);
    403         return false;
    404     }
    405     SkASSERT(this->points() && ref.points());
    406     if (0 != memcmp(this->points(),
    407                     ref.points(),
    408                     ref.fPointCnt * sizeof(SkPoint))) {
    409         SkASSERT(!genIDMatch);
    410         return false;
    411     }
    412     if (fConicWeights != ref.fConicWeights) {
    413         SkASSERT(!genIDMatch);
    414         return false;
    415     }
    416     return true;
    417 }
    418 
    419 void SkPathRef::writeToBuffer(SkWBuffer* buffer) const {
    420     SkDEBUGCODE(this->validate();)
    421     SkDEBUGCODE(size_t beforePos = buffer->pos();)
    422 
    423     // Call getBounds() to ensure (as a side-effect) that fBounds
    424     // and fIsFinite are computed.
    425     const SkRect& bounds = this->getBounds();
    426 
    427     int32_t packed = ((fIsFinite & 1) << kIsFinite_SerializationShift) |
    428                      (fSegmentMask << kSegmentMask_SerializationShift);
    429     buffer->write32(packed);
    430 
    431     // TODO: write gen ID here. Problem: We don't know if we're cross process or not from
    432     // SkWBuffer. Until this is fixed we write 0.
    433     buffer->write32(0);
    434     buffer->write32(fVerbCnt);
    435     buffer->write32(fPointCnt);
    436     buffer->write32(fConicWeights.count());
    437     buffer->write(verbsMemBegin(), fVerbCnt * sizeof(uint8_t));
    438     buffer->write(fPoints, fPointCnt * sizeof(SkPoint));
    439     buffer->write(fConicWeights.begin(), fConicWeights.bytes());
    440     buffer->write(&bounds, sizeof(bounds));
    441 
    442     SkASSERT(buffer->pos() - beforePos == (size_t) this->writeSize());
    443 }
    444 
    445 uint32_t SkPathRef::writeSize() const {
    446     return uint32_t(5 * sizeof(uint32_t) +
    447                     fVerbCnt * sizeof(uint8_t) +
    448                     fPointCnt * sizeof(SkPoint) +
    449                     fConicWeights.bytes() +
    450                     sizeof(SkRect));
    451 }
    452 
    453 void SkPathRef::copy(const SkPathRef& ref,
    454                      int additionalReserveVerbs,
    455                      int additionalReservePoints) {
    456     SkDEBUGCODE(this->validate();)
    457     this->resetToSize(ref.fVerbCnt, ref.fPointCnt, ref.fConicWeights.count(),
    458                         additionalReserveVerbs, additionalReservePoints);
    459     sk_careful_memcpy(this->verbsMemWritable(), ref.verbsMemBegin(), ref.fVerbCnt*sizeof(uint8_t));
    460     sk_careful_memcpy(this->fPoints, ref.fPoints, ref.fPointCnt * sizeof(SkPoint));
    461     fConicWeights = ref.fConicWeights;
    462     fBoundsIsDirty = ref.fBoundsIsDirty;
    463     if (!fBoundsIsDirty) {
    464         fBounds = ref.fBounds;
    465         fIsFinite = ref.fIsFinite;
    466     }
    467     fSegmentMask = ref.fSegmentMask;
    468     fIsOval = ref.fIsOval;
    469     fIsRRect = ref.fIsRRect;
    470     fRRectOrOvalIsCCW = ref.fRRectOrOvalIsCCW;
    471     fRRectOrOvalStartIdx = ref.fRRectOrOvalStartIdx;
    472     SkDEBUGCODE(this->validate();)
    473 }
    474 
    475 
    476 void SkPathRef::interpolate(const SkPathRef& ending, SkScalar weight, SkPathRef* out) const {
    477     const SkScalar* inValues = &ending.getPoints()->fX;
    478     SkScalar* outValues = &out->getPoints()->fX;
    479     int count = out->countPoints() * 2;
    480     for (int index = 0; index < count; ++index) {
    481         outValues[index] = outValues[index] * weight + inValues[index] * (1 - weight);
    482     }
    483     out->fBoundsIsDirty = true;
    484     out->fIsOval = false;
    485     out->fIsRRect = false;
    486 }
    487 
    488 SkPoint* SkPathRef::growForRepeatedVerb(int /*SkPath::Verb*/ verb,
    489                                         int numVbs,
    490                                         SkScalar** weights) {
    491     // This value is just made-up for now. When count is 4, calling memset was much
    492     // slower than just writing the loop. This seems odd, and hopefully in the
    493     // future this will appear to have been a fluke...
    494     static const unsigned int kMIN_COUNT_FOR_MEMSET_TO_BE_FAST = 16;
    495 
    496     SkDEBUGCODE(this->validate();)
    497     int pCnt;
    498     bool dirtyAfterEdit = true;
    499     switch (verb) {
    500         case SkPath::kMove_Verb:
    501             pCnt = numVbs;
    502             dirtyAfterEdit = false;
    503             break;
    504         case SkPath::kLine_Verb:
    505             fSegmentMask |= SkPath::kLine_SegmentMask;
    506             pCnt = numVbs;
    507             break;
    508         case SkPath::kQuad_Verb:
    509             fSegmentMask |= SkPath::kQuad_SegmentMask;
    510             pCnt = 2 * numVbs;
    511             break;
    512         case SkPath::kConic_Verb:
    513             fSegmentMask |= SkPath::kConic_SegmentMask;
    514             pCnt = 2 * numVbs;
    515             break;
    516         case SkPath::kCubic_Verb:
    517             fSegmentMask |= SkPath::kCubic_SegmentMask;
    518             pCnt = 3 * numVbs;
    519             break;
    520         case SkPath::kClose_Verb:
    521             SkDEBUGFAIL("growForRepeatedVerb called for kClose_Verb");
    522             pCnt = 0;
    523             dirtyAfterEdit = false;
    524             break;
    525         case SkPath::kDone_Verb:
    526             SkDEBUGFAIL("growForRepeatedVerb called for kDone");
    527             // fall through
    528         default:
    529             SkDEBUGFAIL("default should not be reached");
    530             pCnt = 0;
    531             dirtyAfterEdit = false;
    532     }
    533 
    534     size_t space = numVbs * sizeof(uint8_t) + pCnt * sizeof (SkPoint);
    535     this->makeSpace(space);
    536 
    537     SkPoint* ret = fPoints + fPointCnt;
    538     uint8_t* vb = fVerbs - fVerbCnt;
    539 
    540     // cast to unsigned, so if kMIN_COUNT_FOR_MEMSET_TO_BE_FAST is defined to
    541     // be 0, the compiler will remove the test/branch entirely.
    542     if ((unsigned)numVbs >= kMIN_COUNT_FOR_MEMSET_TO_BE_FAST) {
    543         memset(vb - numVbs, verb, numVbs);
    544     } else {
    545         for (int i = 0; i < numVbs; ++i) {
    546             vb[~i] = verb;
    547         }
    548     }
    549 
    550     fVerbCnt += numVbs;
    551     fPointCnt += pCnt;
    552     fFreeSpace -= space;
    553     fBoundsIsDirty = true;  // this also invalidates fIsFinite
    554     if (dirtyAfterEdit) {
    555         fIsOval = false;
    556         fIsRRect = false;
    557     }
    558 
    559     if (SkPath::kConic_Verb == verb) {
    560         SkASSERT(weights);
    561         *weights = fConicWeights.append(numVbs);
    562     }
    563 
    564     SkDEBUGCODE(this->validate();)
    565     return ret;
    566 }
    567 
    568 SkPoint* SkPathRef::growForVerb(int /* SkPath::Verb*/ verb, SkScalar weight) {
    569     SkDEBUGCODE(this->validate();)
    570     int pCnt;
    571     bool dirtyAfterEdit = true;
    572     switch (verb) {
    573         case SkPath::kMove_Verb:
    574             pCnt = 1;
    575             dirtyAfterEdit = false;
    576             break;
    577         case SkPath::kLine_Verb:
    578             fSegmentMask |= SkPath::kLine_SegmentMask;
    579             pCnt = 1;
    580             break;
    581         case SkPath::kQuad_Verb:
    582             fSegmentMask |= SkPath::kQuad_SegmentMask;
    583             pCnt = 2;
    584             break;
    585         case SkPath::kConic_Verb:
    586             fSegmentMask |= SkPath::kConic_SegmentMask;
    587             pCnt = 2;
    588             break;
    589         case SkPath::kCubic_Verb:
    590             fSegmentMask |= SkPath::kCubic_SegmentMask;
    591             pCnt = 3;
    592             break;
    593         case SkPath::kClose_Verb:
    594             pCnt = 0;
    595             dirtyAfterEdit = false;
    596             break;
    597         case SkPath::kDone_Verb:
    598             SkDEBUGFAIL("growForVerb called for kDone");
    599             // fall through
    600         default:
    601             SkDEBUGFAIL("default is not reached");
    602             dirtyAfterEdit = false;
    603             pCnt = 0;
    604     }
    605     SkSafeMath safe;
    606     int newPointCnt = safe.addInt(fPointCnt, pCnt);
    607     int newVerbCnt  = safe.addInt(fVerbCnt, 1);
    608     if (!safe) {
    609         SK_ABORT("cannot grow path");
    610     }
    611     size_t space = sizeof(uint8_t) + pCnt * sizeof (SkPoint);
    612     this->makeSpace(space);
    613     this->fVerbs[~fVerbCnt] = verb;
    614     SkPoint* ret = fPoints + fPointCnt;
    615     fVerbCnt = newVerbCnt;
    616     fPointCnt = newPointCnt;
    617     fFreeSpace -= space;
    618     fBoundsIsDirty = true;  // this also invalidates fIsFinite
    619     if (dirtyAfterEdit) {
    620         fIsOval = false;
    621         fIsRRect = false;
    622     }
    623 
    624     if (SkPath::kConic_Verb == verb) {
    625         *fConicWeights.append() = weight;
    626     }
    627 
    628     SkDEBUGCODE(this->validate();)
    629     return ret;
    630 }
    631 
    632 uint32_t SkPathRef::genID() const {
    633     SkASSERT(!fEditorsAttached);
    634     static const uint32_t kMask = (static_cast<int64_t>(1) << SkPathPriv::kPathRefGenIDBitCnt) - 1;
    635     if (!fGenerationID) {
    636         if (0 == fPointCnt && 0 == fVerbCnt) {
    637             fGenerationID = kEmptyGenID;
    638         } else {
    639             static int32_t  gPathRefGenerationID;
    640             // do a loop in case our global wraps around, as we never want to return a 0 or the
    641             // empty ID
    642             do {
    643                 fGenerationID = (sk_atomic_inc(&gPathRefGenerationID) + 1) & kMask;
    644             } while (fGenerationID <= kEmptyGenID);
    645         }
    646     }
    647     return fGenerationID;
    648 }
    649 
    650 void SkPathRef::addGenIDChangeListener(GenIDChangeListener* listener) {
    651     if (nullptr == listener || this == gEmpty) {
    652         delete listener;
    653         return;
    654     }
    655     *fGenIDChangeListeners.append() = listener;
    656 }
    657 
    658 // we need to be called *before* the genID gets changed or zerod
    659 void SkPathRef::callGenIDChangeListeners() {
    660     for (int i = 0; i < fGenIDChangeListeners.count(); i++) {
    661         fGenIDChangeListeners[i]->onChange();
    662     }
    663 
    664     // Listeners get at most one shot, so whether these triggered or not, blow them away.
    665     fGenIDChangeListeners.deleteAll();
    666 }
    667 
    668 SkRRect SkPathRef::getRRect() const {
    669     const SkRect& bounds = this->getBounds();
    670     SkVector radii[4] = {{0, 0}, {0, 0}, {0, 0}, {0, 0}};
    671     Iter iter(*this);
    672     SkPoint pts[4];
    673     uint8_t verb = iter.next(pts);
    674     SkASSERT(SkPath::kMove_Verb == verb);
    675     while ((verb = iter.next(pts)) != SkPath::kDone_Verb) {
    676         if (SkPath::kConic_Verb == verb) {
    677             SkVector v1_0 = pts[1] - pts[0];
    678             SkVector v2_1 = pts[2] - pts[1];
    679             SkVector dxdy;
    680             if (v1_0.fX) {
    681                 SkASSERT(!v2_1.fX && !v1_0.fY);
    682                 dxdy.set(SkScalarAbs(v1_0.fX), SkScalarAbs(v2_1.fY));
    683             } else if (!v1_0.fY) {
    684                 SkASSERT(!v2_1.fX || !v2_1.fY);
    685                 dxdy.set(SkScalarAbs(v2_1.fX), SkScalarAbs(v2_1.fY));
    686             } else {
    687                 SkASSERT(!v2_1.fY);
    688                 dxdy.set(SkScalarAbs(v2_1.fX), SkScalarAbs(v1_0.fY));
    689             }
    690             SkRRect::Corner corner =
    691                     pts[1].fX == bounds.fLeft ?
    692                         pts[1].fY == bounds.fTop ?
    693                             SkRRect::kUpperLeft_Corner : SkRRect::kLowerLeft_Corner :
    694                     pts[1].fY == bounds.fTop ?
    695                             SkRRect::kUpperRight_Corner : SkRRect::kLowerRight_Corner;
    696             SkASSERT(!radii[corner].fX && !radii[corner].fY);
    697             radii[corner] = dxdy;
    698         } else {
    699             SkASSERT((verb == SkPath::kLine_Verb
    700                     && (!(pts[1].fX - pts[0].fX) || !(pts[1].fY - pts[0].fY)))
    701                     || verb == SkPath::kClose_Verb);
    702         }
    703     }
    704     SkRRect rrect;
    705     rrect.setRectRadii(bounds, radii);
    706     return rrect;
    707 }
    708 
    709 ///////////////////////////////////////////////////////////////////////////////
    710 
    711 SkPathRef::Iter::Iter() {
    712 #ifdef SK_DEBUG
    713     fPts = nullptr;
    714     fConicWeights = nullptr;
    715 #endif
    716     // need to init enough to make next() harmlessly return kDone_Verb
    717     fVerbs = nullptr;
    718     fVerbStop = nullptr;
    719 }
    720 
    721 SkPathRef::Iter::Iter(const SkPathRef& path) {
    722     this->setPathRef(path);
    723 }
    724 
    725 void SkPathRef::Iter::setPathRef(const SkPathRef& path) {
    726     fPts = path.points();
    727     fVerbs = path.verbs();
    728     fVerbStop = path.verbsMemBegin();
    729     fConicWeights = path.conicWeights();
    730     if (fConicWeights) {
    731       fConicWeights -= 1;  // begin one behind
    732     }
    733 
    734     // Don't allow iteration through non-finite points.
    735     if (!path.isFinite()) {
    736         fVerbStop = fVerbs;
    737     }
    738 }
    739 
    740 uint8_t SkPathRef::Iter::next(SkPoint pts[4]) {
    741     SkASSERT(pts);
    742     if (fVerbs == fVerbStop) {
    743         return (uint8_t) SkPath::kDone_Verb;
    744     }
    745 
    746     // fVerbs points one beyond next verb so decrement first.
    747     unsigned verb = *(--fVerbs);
    748     const SkPoint* srcPts = fPts;
    749 
    750     switch (verb) {
    751         case SkPath::kMove_Verb:
    752             pts[0] = srcPts[0];
    753             srcPts += 1;
    754             break;
    755         case SkPath::kLine_Verb:
    756             pts[0] = srcPts[-1];
    757             pts[1] = srcPts[0];
    758             srcPts += 1;
    759             break;
    760         case SkPath::kConic_Verb:
    761             fConicWeights += 1;
    762             // fall-through
    763         case SkPath::kQuad_Verb:
    764             pts[0] = srcPts[-1];
    765             pts[1] = srcPts[0];
    766             pts[2] = srcPts[1];
    767             srcPts += 2;
    768             break;
    769         case SkPath::kCubic_Verb:
    770             pts[0] = srcPts[-1];
    771             pts[1] = srcPts[0];
    772             pts[2] = srcPts[1];
    773             pts[3] = srcPts[2];
    774             srcPts += 3;
    775             break;
    776         case SkPath::kClose_Verb:
    777             break;
    778         case SkPath::kDone_Verb:
    779             SkASSERT(fVerbs == fVerbStop);
    780             break;
    781     }
    782     fPts = srcPts;
    783     return (uint8_t) verb;
    784 }
    785 
    786 uint8_t SkPathRef::Iter::peek() const {
    787     const uint8_t* next = fVerbs - 1;
    788     return next <= fVerbStop ? (uint8_t) SkPath::kDone_Verb : *next;
    789 }
    790 
    791 
    792 bool SkPathRef::isValid() const {
    793     if (static_cast<ptrdiff_t>(fFreeSpace) < 0) {
    794         return false;
    795     }
    796     if (reinterpret_cast<intptr_t>(fVerbs) - reinterpret_cast<intptr_t>(fPoints) < 0) {
    797         return false;
    798     }
    799     if ((nullptr == fPoints) != (nullptr == fVerbs)) {
    800         return false;
    801     }
    802     if (nullptr == fPoints && 0 != fFreeSpace) {
    803         return false;
    804     }
    805     if (nullptr == fPoints && fPointCnt) {
    806         return false;
    807     }
    808     if (nullptr == fVerbs && fVerbCnt) {
    809         return false;
    810     }
    811     if (this->currSize() !=
    812                 fFreeSpace + sizeof(SkPoint) * fPointCnt + sizeof(uint8_t) * fVerbCnt) {
    813         return false;
    814     }
    815 
    816     if (fIsOval || fIsRRect) {
    817         // Currently we don't allow both of these to be set, even though ovals are ro
    818         if (fIsOval == fIsRRect) {
    819             return false;
    820         }
    821         if (fIsOval) {
    822             if (fRRectOrOvalStartIdx >= 4) {
    823                 return false;
    824             }
    825         } else {
    826             if (fRRectOrOvalStartIdx >= 8) {
    827                 return false;
    828             }
    829         }
    830     }
    831 
    832     if (!fBoundsIsDirty && !fBounds.isEmpty()) {
    833         bool isFinite = true;
    834         Sk2s leftTop = Sk2s(fBounds.fLeft, fBounds.fTop);
    835         Sk2s rightBot = Sk2s(fBounds.fRight, fBounds.fBottom);
    836         for (int i = 0; i < fPointCnt; ++i) {
    837             Sk2s point = Sk2s(fPoints[i].fX, fPoints[i].fY);
    838 #ifdef SK_DEBUG
    839             if (fPoints[i].isFinite() &&
    840                 ((point < leftTop).anyTrue() || (point > rightBot).anyTrue())) {
    841                 SkDebugf("bounds: %f %f %f %f\n",
    842                          fBounds.fLeft, fBounds.fTop, fBounds.fRight, fBounds.fBottom);
    843                 for (int j = 0; j < fPointCnt; ++j) {
    844                     if (i == j) {
    845                         SkDebugf("*");
    846                     }
    847                     SkDebugf("%f %f\n", fPoints[j].fX, fPoints[j].fY);
    848                 }
    849             }
    850 #endif
    851 
    852             if (fPoints[i].isFinite() && (point < leftTop).anyTrue() && !(point > rightBot).anyTrue())
    853                 return false;
    854             if (!fPoints[i].isFinite()) {
    855                 isFinite = false;
    856             }
    857         }
    858         if (SkToBool(fIsFinite) != isFinite) {
    859             return false;
    860         }
    861     }
    862 
    863 #ifdef SK_DEBUG_PATH
    864     uint32_t mask = 0;
    865     for (int i = 0; i < fVerbCnt; ++i) {
    866         switch (fVerbs[~i]) {
    867             case SkPath::kMove_Verb:
    868                 break;
    869             case SkPath::kLine_Verb:
    870                 mask |= SkPath::kLine_SegmentMask;
    871                 break;
    872             case SkPath::kQuad_Verb:
    873                 mask |= SkPath::kQuad_SegmentMask;
    874                 break;
    875             case SkPath::kConic_Verb:
    876                 mask |= SkPath::kConic_SegmentMask;
    877                 break;
    878             case SkPath::kCubic_Verb:
    879                 mask |= SkPath::kCubic_SegmentMask;
    880                 break;
    881             case SkPath::kClose_Verb:
    882                 break;
    883             case SkPath::kDone_Verb:
    884                 SkDEBUGFAIL("Done verb shouldn't be recorded.");
    885                 break;
    886             default:
    887                 SkDEBUGFAIL("Unknown Verb");
    888                 break;
    889         }
    890     }
    891     if (mask != fSegmentMask) {
    892         return false;
    893     }
    894 #endif // SK_DEBUG_PATH
    895     return true;
    896 }
    897