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      1 /*
      2  * Copyright (C) 2014 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "Canvas.h"
     18 
     19 #include <SkCanvas.h>
     20 #include <SkClipStack.h>
     21 #include <SkDevice.h>
     22 #include <SkDeque.h>
     23 #include <SkDrawFilter.h>
     24 #include <SkGraphics.h>
     25 #include <SkShader.h>
     26 #include <SkTArray.h>
     27 #include <SkTemplates.h>
     28 
     29 namespace android {
     30 
     31 // Holds an SkCanvas reference plus additional native data.
     32 class SkiaCanvas : public Canvas {
     33 public:
     34     explicit SkiaCanvas(const SkBitmap& bitmap);
     35 
     36     /**
     37      *  Create a new SkiaCanvas.
     38      *
     39      *  @param canvas SkCanvas to handle calls made to this SkiaCanvas. Must
     40      *      not be NULL. This constructor will ref() the SkCanvas, and unref()
     41      *      it in its destructor.
     42      */
     43     explicit SkiaCanvas(SkCanvas* canvas) : mCanvas(canvas) {
     44         SkASSERT(canvas);
     45         canvas->ref();
     46     }
     47 
     48     virtual SkCanvas* asSkCanvas() override {
     49         return mCanvas.get();
     50     }
     51 
     52     virtual void setBitmap(const SkBitmap& bitmap) override;
     53 
     54     virtual bool isOpaque() override;
     55     virtual int width() override;
     56     virtual int height() override;
     57 
     58     virtual int getSaveCount() const override;
     59     virtual int save(SkCanvas::SaveFlags flags) override;
     60     virtual void restore() override;
     61     virtual void restoreToCount(int saveCount) override;
     62 
     63     virtual int saveLayer(float left, float top, float right, float bottom,
     64                 const SkPaint* paint, SkCanvas::SaveFlags flags) override;
     65     virtual int saveLayerAlpha(float left, float top, float right, float bottom,
     66             int alpha, SkCanvas::SaveFlags flags) override;
     67 
     68     virtual void getMatrix(SkMatrix* outMatrix) const override;
     69     virtual void setMatrix(const SkMatrix& matrix) override;
     70     virtual void setLocalMatrix(const SkMatrix& matrix) override { this->setMatrix(matrix); }
     71     virtual void concat(const SkMatrix& matrix) override;
     72     virtual void rotate(float degrees) override;
     73     virtual void scale(float sx, float sy) override;
     74     virtual void skew(float sx, float sy) override;
     75     virtual void translate(float dx, float dy) override;
     76 
     77     virtual bool getClipBounds(SkRect* outRect) const override;
     78     virtual bool quickRejectRect(float left, float top, float right, float bottom) const override;
     79     virtual bool quickRejectPath(const SkPath& path) const override;
     80     virtual bool clipRect(float left, float top, float right, float bottom,
     81             SkRegion::Op op) override;
     82     virtual bool clipPath(const SkPath* path, SkRegion::Op op) override;
     83     virtual bool clipRegion(const SkRegion* region, SkRegion::Op op) override;
     84 
     85     virtual SkDrawFilter* getDrawFilter() override;
     86     virtual void setDrawFilter(SkDrawFilter* drawFilter) override;
     87 
     88     virtual void drawColor(int color, SkXfermode::Mode mode) override;
     89     virtual void drawPaint(const SkPaint& paint) override;
     90 
     91     virtual void drawPoint(float x, float y, const SkPaint& paint) override;
     92     virtual void drawPoints(const float* points, int count, const SkPaint& paint) override;
     93     virtual void drawLine(float startX, float startY, float stopX, float stopY,
     94             const SkPaint& paint) override;
     95     virtual void drawLines(const float* points, int count, const SkPaint& paint) override;
     96     virtual void drawRect(float left, float top, float right, float bottom,
     97             const SkPaint& paint) override;
     98     virtual void drawRoundRect(float left, float top, float right, float bottom,
     99             float rx, float ry, const SkPaint& paint) override;
    100     virtual void drawCircle(float x, float y, float radius, const SkPaint& paint) override;
    101     virtual void drawOval(float left, float top, float right, float bottom,
    102             const SkPaint& paint) override;
    103     virtual void drawArc(float left, float top, float right, float bottom,
    104             float startAngle, float sweepAngle, bool useCenter, const SkPaint& paint) override;
    105     virtual void drawPath(const SkPath& path, const SkPaint& paint) override;
    106     virtual void drawVertices(SkCanvas::VertexMode vertexMode, int vertexCount,
    107             const float* verts, const float* tex, const int* colors,
    108             const uint16_t* indices, int indexCount, const SkPaint& paint) override;
    109 
    110     virtual void drawBitmap(const SkBitmap& bitmap, float left, float top,
    111             const SkPaint* paint) override;
    112     virtual void drawBitmap(const SkBitmap& bitmap, const SkMatrix& matrix,
    113             const SkPaint* paint) override;
    114     virtual void drawBitmap(const SkBitmap& bitmap, float srcLeft, float srcTop,
    115             float srcRight, float srcBottom, float dstLeft, float dstTop,
    116             float dstRight, float dstBottom, const SkPaint* paint) override;
    117     virtual void drawBitmapMesh(const SkBitmap& bitmap, int meshWidth, int meshHeight,
    118             const float* vertices, const int* colors, const SkPaint* paint) override;
    119 
    120     virtual void drawText(const uint16_t* text, const float* positions, int count,
    121             const SkPaint& paint, float x, float y,
    122             float boundsLeft, float boundsTop, float boundsRight, float boundsBottom,
    123             float totalAdvance) override;
    124     virtual void drawPosText(const uint16_t* text, const float* positions, int count,
    125             int posCount, const SkPaint& paint) override;
    126     virtual void drawTextOnPath(const uint16_t* glyphs, int count, const SkPath& path,
    127             float hOffset, float vOffset, const SkPaint& paint) override;
    128 
    129     virtual bool drawTextAbsolutePos() const  override { return true; }
    130 
    131 private:
    132     struct SaveRec {
    133         int                 saveCount;
    134         SkCanvas::SaveFlags saveFlags;
    135     };
    136 
    137     void recordPartialSave(SkCanvas::SaveFlags flags);
    138     void saveClipsForFrame(SkTArray<SkClipStack::Element>& clips, int frameSaveCount);
    139     void applyClips(const SkTArray<SkClipStack::Element>& clips);
    140 
    141     void drawPoints(const float* points, int count, const SkPaint& paint,
    142                     SkCanvas::PointMode mode);
    143     void drawTextDecorations(float x, float y, float length, const SkPaint& paint);
    144 
    145     SkAutoTUnref<SkCanvas> mCanvas;
    146     SkAutoTDelete<SkDeque> mSaveStack; // lazily allocated, tracks partial saves.
    147 };
    148 
    149 Canvas* Canvas::create_canvas(const SkBitmap& bitmap) {
    150     return new SkiaCanvas(bitmap);
    151 }
    152 
    153 Canvas* Canvas::create_canvas(SkCanvas* skiaCanvas) {
    154     return new SkiaCanvas(skiaCanvas);
    155 }
    156 
    157 SkiaCanvas::SkiaCanvas(const SkBitmap& bitmap) {
    158     mCanvas.reset(new SkCanvas(bitmap));
    159 }
    160 
    161 // ----------------------------------------------------------------------------
    162 // Canvas state operations: Replace Bitmap
    163 // ----------------------------------------------------------------------------
    164 
    165 class ClipCopier : public SkCanvas::ClipVisitor {
    166 public:
    167     ClipCopier(SkCanvas* dstCanvas) : m_dstCanvas(dstCanvas) {}
    168 
    169     virtual void clipRect(const SkRect& rect, SkRegion::Op op, bool antialias) {
    170         m_dstCanvas->clipRect(rect, op, antialias);
    171     }
    172     virtual void clipRRect(const SkRRect& rrect, SkRegion::Op op, bool antialias) {
    173         m_dstCanvas->clipRRect(rrect, op, antialias);
    174     }
    175     virtual void clipPath(const SkPath& path, SkRegion::Op op, bool antialias) {
    176         m_dstCanvas->clipPath(path, op, antialias);
    177     }
    178 
    179 private:
    180     SkCanvas* m_dstCanvas;
    181 };
    182 
    183 void SkiaCanvas::setBitmap(const SkBitmap& bitmap) {
    184     SkCanvas* newCanvas = new SkCanvas(bitmap);
    185     SkASSERT(newCanvas);
    186 
    187     if (!bitmap.isNull()) {
    188         // Copy the canvas matrix & clip state.
    189         newCanvas->setMatrix(mCanvas->getTotalMatrix());
    190         if (NULL != mCanvas->getDevice() && NULL != newCanvas->getDevice()) {
    191             ClipCopier copier(newCanvas);
    192             mCanvas->replayClips(&copier);
    193         }
    194     }
    195 
    196     // unrefs the existing canvas
    197     mCanvas.reset(newCanvas);
    198 
    199     // clean up the old save stack
    200     mSaveStack.reset(NULL);
    201 }
    202 
    203 // ----------------------------------------------------------------------------
    204 // Canvas state operations
    205 // ----------------------------------------------------------------------------
    206 
    207 bool SkiaCanvas::isOpaque() {
    208     return mCanvas->getDevice()->accessBitmap(false).isOpaque();
    209 }
    210 
    211 int SkiaCanvas::width() {
    212     return mCanvas->getBaseLayerSize().width();
    213 }
    214 
    215 int SkiaCanvas::height() {
    216     return mCanvas->getBaseLayerSize().height();
    217 }
    218 
    219 // ----------------------------------------------------------------------------
    220 // Canvas state operations: Save (layer)
    221 // ----------------------------------------------------------------------------
    222 
    223 int SkiaCanvas::getSaveCount() const {
    224     return mCanvas->getSaveCount();
    225 }
    226 
    227 int SkiaCanvas::save(SkCanvas::SaveFlags flags) {
    228     int count = mCanvas->save();
    229     recordPartialSave(flags);
    230     return count;
    231 }
    232 
    233 void SkiaCanvas::restore() {
    234     const SaveRec* rec = (NULL == mSaveStack.get())
    235             ? NULL
    236             : static_cast<SaveRec*>(mSaveStack->back());
    237     int currentSaveCount = mCanvas->getSaveCount() - 1;
    238     SkASSERT(NULL == rec || currentSaveCount >= rec->saveCount);
    239 
    240     if (NULL == rec || rec->saveCount != currentSaveCount) {
    241         // Fast path - no record for this frame.
    242         mCanvas->restore();
    243         return;
    244     }
    245 
    246     bool preserveMatrix = !(rec->saveFlags & SkCanvas::kMatrix_SaveFlag);
    247     bool preserveClip   = !(rec->saveFlags & SkCanvas::kClip_SaveFlag);
    248 
    249     SkMatrix savedMatrix;
    250     if (preserveMatrix) {
    251         savedMatrix = mCanvas->getTotalMatrix();
    252     }
    253 
    254     SkTArray<SkClipStack::Element> savedClips;
    255     if (preserveClip) {
    256         saveClipsForFrame(savedClips, currentSaveCount);
    257     }
    258 
    259     mCanvas->restore();
    260 
    261     if (preserveMatrix) {
    262         mCanvas->setMatrix(savedMatrix);
    263     }
    264 
    265     if (preserveClip && !savedClips.empty()) {
    266         applyClips(savedClips);
    267     }
    268 
    269     mSaveStack->pop_back();
    270 }
    271 
    272 void SkiaCanvas::restoreToCount(int restoreCount) {
    273     while (mCanvas->getSaveCount() > restoreCount) {
    274         this->restore();
    275     }
    276 }
    277 
    278 int SkiaCanvas::saveLayer(float left, float top, float right, float bottom,
    279             const SkPaint* paint, SkCanvas::SaveFlags flags) {
    280     SkRect bounds = SkRect::MakeLTRB(left, top, right, bottom);
    281     int count = mCanvas->saveLayer(&bounds, paint, flags | SkCanvas::kMatrixClip_SaveFlag);
    282     recordPartialSave(flags);
    283     return count;
    284 }
    285 
    286 int SkiaCanvas::saveLayerAlpha(float left, float top, float right, float bottom,
    287         int alpha, SkCanvas::SaveFlags flags) {
    288     SkRect bounds = SkRect::MakeLTRB(left, top, right, bottom);
    289     int count = mCanvas->saveLayerAlpha(&bounds, alpha, flags | SkCanvas::kMatrixClip_SaveFlag);
    290     recordPartialSave(flags);
    291     return count;
    292 }
    293 
    294 // ----------------------------------------------------------------------------
    295 // functions to emulate legacy SaveFlags (i.e. independent matrix/clip flags)
    296 // ----------------------------------------------------------------------------
    297 
    298 void SkiaCanvas::recordPartialSave(SkCanvas::SaveFlags flags) {
    299     // A partial save is a save operation which doesn't capture the full canvas state.
    300     // (either kMatrix_SaveFlags or kClip_SaveFlag is missing).
    301 
    302     // Mask-out non canvas state bits.
    303     flags = static_cast<SkCanvas::SaveFlags>(flags & SkCanvas::kMatrixClip_SaveFlag);
    304 
    305     if (SkCanvas::kMatrixClip_SaveFlag == flags) {
    306         // not a partial save.
    307         return;
    308     }
    309 
    310     if (NULL == mSaveStack.get()) {
    311         mSaveStack.reset(SkNEW_ARGS(SkDeque, (sizeof(struct SaveRec), 8)));
    312     }
    313 
    314     SaveRec* rec = static_cast<SaveRec*>(mSaveStack->push_back());
    315     // Store the save counter in the SkClipStack domain.
    316     // (0-based, equal to the number of save ops on the stack).
    317     rec->saveCount = mCanvas->getSaveCount() - 1;
    318     rec->saveFlags = flags;
    319 }
    320 
    321 void SkiaCanvas::saveClipsForFrame(SkTArray<SkClipStack::Element>& clips, int frameSaveCount) {
    322     SkClipStack::Iter clipIterator(*mCanvas->getClipStack(),
    323                                    SkClipStack::Iter::kTop_IterStart);
    324     while (const SkClipStack::Element* elem = clipIterator.next()) {
    325         if (elem->getSaveCount() < frameSaveCount) {
    326             // done with the current frame.
    327             break;
    328         }
    329         SkASSERT(elem->getSaveCount() == frameSaveCount);
    330         clips.push_back(*elem);
    331     }
    332 }
    333 
    334 void SkiaCanvas::applyClips(const SkTArray<SkClipStack::Element>& clips) {
    335     ClipCopier clipCopier(mCanvas);
    336 
    337     // The clip stack stores clips in device space.
    338     SkMatrix origMatrix = mCanvas->getTotalMatrix();
    339     mCanvas->resetMatrix();
    340 
    341     // We pushed the clips in reverse order.
    342     for (int i = clips.count() - 1; i >= 0; --i) {
    343         clips[i].replay(&clipCopier);
    344     }
    345 
    346     mCanvas->setMatrix(origMatrix);
    347 }
    348 
    349 // ----------------------------------------------------------------------------
    350 // Canvas state operations: Matrix
    351 // ----------------------------------------------------------------------------
    352 
    353 void SkiaCanvas::getMatrix(SkMatrix* outMatrix) const {
    354     *outMatrix = mCanvas->getTotalMatrix();
    355 }
    356 
    357 void SkiaCanvas::setMatrix(const SkMatrix& matrix) {
    358     mCanvas->setMatrix(matrix);
    359 }
    360 
    361 void SkiaCanvas::concat(const SkMatrix& matrix) {
    362     mCanvas->concat(matrix);
    363 }
    364 
    365 void SkiaCanvas::rotate(float degrees) {
    366     mCanvas->rotate(degrees);
    367 }
    368 
    369 void SkiaCanvas::scale(float sx, float sy) {
    370     mCanvas->scale(sx, sy);
    371 }
    372 
    373 void SkiaCanvas::skew(float sx, float sy) {
    374     mCanvas->skew(sx, sy);
    375 }
    376 
    377 void SkiaCanvas::translate(float dx, float dy) {
    378     mCanvas->translate(dx, dy);
    379 }
    380 
    381 // ----------------------------------------------------------------------------
    382 // Canvas state operations: Clips
    383 // ----------------------------------------------------------------------------
    384 
    385 // This function is a mirror of SkCanvas::getClipBounds except that it does
    386 // not outset the edge of the clip to account for anti-aliasing. There is
    387 // a skia bug to investigate pushing this logic into back into skia.
    388 // (see https://code.google.com/p/skia/issues/detail?id=1303)
    389 bool SkiaCanvas::getClipBounds(SkRect* outRect) const {
    390     SkIRect ibounds;
    391     if (!mCanvas->getClipDeviceBounds(&ibounds)) {
    392         return false;
    393     }
    394 
    395     SkMatrix inverse;
    396     // if we can't invert the CTM, we can't return local clip bounds
    397     if (!mCanvas->getTotalMatrix().invert(&inverse)) {
    398         if (outRect) {
    399             outRect->setEmpty();
    400         }
    401         return false;
    402     }
    403 
    404     if (NULL != outRect) {
    405         SkRect r = SkRect::Make(ibounds);
    406         inverse.mapRect(outRect, r);
    407     }
    408     return true;
    409 }
    410 
    411 bool SkiaCanvas::quickRejectRect(float left, float top, float right, float bottom) const {
    412     SkRect bounds = SkRect::MakeLTRB(left, top, right, bottom);
    413     return mCanvas->quickReject(bounds);
    414 }
    415 
    416 bool SkiaCanvas::quickRejectPath(const SkPath& path) const {
    417     return mCanvas->quickReject(path);
    418 }
    419 
    420 bool SkiaCanvas::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {
    421     SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
    422     mCanvas->clipRect(rect, op);
    423     return !mCanvas->isClipEmpty();
    424 }
    425 
    426 bool SkiaCanvas::clipPath(const SkPath* path, SkRegion::Op op) {
    427     mCanvas->clipPath(*path, op);
    428     return !mCanvas->isClipEmpty();
    429 }
    430 
    431 bool SkiaCanvas::clipRegion(const SkRegion* region, SkRegion::Op op) {
    432     SkPath rgnPath;
    433     if (region->getBoundaryPath(&rgnPath)) {
    434         // The region is specified in device space.
    435         SkMatrix savedMatrix = mCanvas->getTotalMatrix();
    436         mCanvas->resetMatrix();
    437         mCanvas->clipPath(rgnPath, op);
    438         mCanvas->setMatrix(savedMatrix);
    439     } else {
    440         mCanvas->clipRect(SkRect::MakeEmpty(), op);
    441     }
    442     return !mCanvas->isClipEmpty();
    443 }
    444 
    445 // ----------------------------------------------------------------------------
    446 // Canvas state operations: Filters
    447 // ----------------------------------------------------------------------------
    448 
    449 SkDrawFilter* SkiaCanvas::getDrawFilter() {
    450     return mCanvas->getDrawFilter();
    451 }
    452 
    453 void SkiaCanvas::setDrawFilter(SkDrawFilter* drawFilter) {
    454     mCanvas->setDrawFilter(drawFilter);
    455 }
    456 
    457 // ----------------------------------------------------------------------------
    458 // Canvas draw operations
    459 // ----------------------------------------------------------------------------
    460 
    461 void SkiaCanvas::drawColor(int color, SkXfermode::Mode mode) {
    462     mCanvas->drawColor(color, mode);
    463 }
    464 
    465 void SkiaCanvas::drawPaint(const SkPaint& paint) {
    466     mCanvas->drawPaint(paint);
    467 }
    468 
    469 // ----------------------------------------------------------------------------
    470 // Canvas draw operations: Geometry
    471 // ----------------------------------------------------------------------------
    472 
    473 void SkiaCanvas::drawPoints(const float* points, int count, const SkPaint& paint,
    474                             SkCanvas::PointMode mode) {
    475     // convert the floats into SkPoints
    476     count >>= 1;    // now it is the number of points
    477     SkAutoSTMalloc<32, SkPoint> storage(count);
    478     SkPoint* pts = storage.get();
    479     for (int i = 0; i < count; i++) {
    480         pts[i].set(points[0], points[1]);
    481         points += 2;
    482     }
    483     mCanvas->drawPoints(mode, count, pts, paint);
    484 }
    485 
    486 
    487 void SkiaCanvas::drawPoint(float x, float y, const SkPaint& paint) {
    488     mCanvas->drawPoint(x, y, paint);
    489 }
    490 
    491 void SkiaCanvas::drawPoints(const float* points, int count, const SkPaint& paint) {
    492     this->drawPoints(points, count, paint, SkCanvas::kPoints_PointMode);
    493 }
    494 
    495 void SkiaCanvas::drawLine(float startX, float startY, float stopX, float stopY,
    496                           const SkPaint& paint) {
    497     mCanvas->drawLine(startX, startY, stopX, stopY, paint);
    498 }
    499 
    500 void SkiaCanvas::drawLines(const float* points, int count, const SkPaint& paint) {
    501     this->drawPoints(points, count, paint, SkCanvas::kLines_PointMode);
    502 }
    503 
    504 void SkiaCanvas::drawRect(float left, float top, float right, float bottom,
    505         const SkPaint& paint) {
    506     mCanvas->drawRectCoords(left, top, right, bottom, paint);
    507 
    508 }
    509 
    510 void SkiaCanvas::drawRoundRect(float left, float top, float right, float bottom,
    511         float rx, float ry, const SkPaint& paint) {
    512     SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
    513     mCanvas->drawRoundRect(rect, rx, ry, paint);
    514 }
    515 
    516 void SkiaCanvas::drawCircle(float x, float y, float radius, const SkPaint& paint) {
    517     mCanvas->drawCircle(x, y, radius, paint);
    518 }
    519 
    520 void SkiaCanvas::drawOval(float left, float top, float right, float bottom, const SkPaint& paint) {
    521     SkRect oval = SkRect::MakeLTRB(left, top, right, bottom);
    522     mCanvas->drawOval(oval, paint);
    523 }
    524 
    525 void SkiaCanvas::drawArc(float left, float top, float right, float bottom,
    526         float startAngle, float sweepAngle, bool useCenter, const SkPaint& paint) {
    527     SkRect arc = SkRect::MakeLTRB(left, top, right, bottom);
    528     mCanvas->drawArc(arc, startAngle, sweepAngle, useCenter, paint);
    529 }
    530 
    531 void SkiaCanvas::drawPath(const SkPath& path, const SkPaint& paint) {
    532     mCanvas->drawPath(path, paint);
    533 }
    534 
    535 void SkiaCanvas::drawVertices(SkCanvas::VertexMode vertexMode, int vertexCount,
    536                               const float* verts, const float* texs, const int* colors,
    537                               const uint16_t* indices, int indexCount, const SkPaint& paint) {
    538 #ifndef SK_SCALAR_IS_FLOAT
    539     SkDEBUGFAIL("SkScalar must be a float for these conversions to be valid");
    540 #endif
    541     const int ptCount = vertexCount >> 1;
    542     mCanvas->drawVertices(vertexMode, ptCount, (SkPoint*)verts, (SkPoint*)texs,
    543                           (SkColor*)colors, NULL, indices, indexCount, paint);
    544 }
    545 
    546 // ----------------------------------------------------------------------------
    547 // Canvas draw operations: Bitmaps
    548 // ----------------------------------------------------------------------------
    549 
    550 void SkiaCanvas::drawBitmap(const SkBitmap& bitmap, float left, float top, const SkPaint* paint) {
    551     mCanvas->drawBitmap(bitmap, left, top, paint);
    552 }
    553 
    554 void SkiaCanvas::drawBitmap(const SkBitmap& bitmap, const SkMatrix& matrix, const SkPaint* paint) {
    555     SkAutoCanvasRestore acr(mCanvas, true);
    556     mCanvas->concat(matrix);
    557     mCanvas->drawBitmap(bitmap, 0, 0, paint);
    558 }
    559 
    560 void SkiaCanvas::drawBitmap(const SkBitmap& bitmap, float srcLeft, float srcTop,
    561                             float srcRight, float srcBottom, float dstLeft, float dstTop,
    562                             float dstRight, float dstBottom, const SkPaint* paint) {
    563     SkRect srcRect = SkRect::MakeLTRB(srcLeft, srcTop, srcRight, srcBottom);
    564     SkRect dstRect = SkRect::MakeLTRB(dstLeft, dstTop, dstRight, dstBottom);
    565     mCanvas->drawBitmapRectToRect(bitmap, &srcRect, dstRect, paint);
    566 }
    567 
    568 void SkiaCanvas::drawBitmapMesh(const SkBitmap& bitmap, int meshWidth, int meshHeight,
    569         const float* vertices, const int* colors, const SkPaint* paint) {
    570 
    571     const int ptCount = (meshWidth + 1) * (meshHeight + 1);
    572     const int indexCount = meshWidth * meshHeight * 6;
    573 
    574     /*  Our temp storage holds 2 or 3 arrays.
    575         texture points [ptCount * sizeof(SkPoint)]
    576         optionally vertex points [ptCount * sizeof(SkPoint)] if we need a
    577             copy to convert from float to fixed
    578         indices [ptCount * sizeof(uint16_t)]
    579     */
    580     ssize_t storageSize = ptCount * sizeof(SkPoint); // texs[]
    581     storageSize += indexCount * sizeof(uint16_t);  // indices[]
    582 
    583 
    584 #ifndef SK_SCALAR_IS_FLOAT
    585     SkDEBUGFAIL("SkScalar must be a float for these conversions to be valid");
    586 #endif
    587     SkAutoMalloc storage(storageSize);
    588     SkPoint* texs = (SkPoint*)storage.get();
    589     uint16_t* indices = (uint16_t*)(texs + ptCount);
    590 
    591     // cons up texture coordinates and indices
    592     {
    593         const SkScalar w = SkIntToScalar(bitmap.width());
    594         const SkScalar h = SkIntToScalar(bitmap.height());
    595         const SkScalar dx = w / meshWidth;
    596         const SkScalar dy = h / meshHeight;
    597 
    598         SkPoint* texsPtr = texs;
    599         SkScalar y = 0;
    600         for (int i = 0; i <= meshHeight; i++) {
    601             if (i == meshHeight) {
    602                 y = h;  // to ensure numerically we hit h exactly
    603             }
    604             SkScalar x = 0;
    605             for (int j = 0; j < meshWidth; j++) {
    606                 texsPtr->set(x, y);
    607                 texsPtr += 1;
    608                 x += dx;
    609             }
    610             texsPtr->set(w, y);
    611             texsPtr += 1;
    612             y += dy;
    613         }
    614         SkASSERT(texsPtr - texs == ptCount);
    615     }
    616 
    617     // cons up indices
    618     {
    619         uint16_t* indexPtr = indices;
    620         int index = 0;
    621         for (int i = 0; i < meshHeight; i++) {
    622             for (int j = 0; j < meshWidth; j++) {
    623                 // lower-left triangle
    624                 *indexPtr++ = index;
    625                 *indexPtr++ = index + meshWidth + 1;
    626                 *indexPtr++ = index + meshWidth + 2;
    627                 // upper-right triangle
    628                 *indexPtr++ = index;
    629                 *indexPtr++ = index + meshWidth + 2;
    630                 *indexPtr++ = index + 1;
    631                 // bump to the next cell
    632                 index += 1;
    633             }
    634             // bump to the next row
    635             index += 1;
    636         }
    637         SkASSERT(indexPtr - indices == indexCount);
    638         SkASSERT((char*)indexPtr - (char*)storage.get() == storageSize);
    639     }
    640 
    641     // double-check that we have legal indices
    642 #ifdef SK_DEBUG
    643     {
    644         for (int i = 0; i < indexCount; i++) {
    645             SkASSERT((unsigned)indices[i] < (unsigned)ptCount);
    646         }
    647     }
    648 #endif
    649 
    650     // cons-up a shader for the bitmap
    651     SkPaint tmpPaint;
    652     if (paint) {
    653         tmpPaint = *paint;
    654     }
    655     SkShader* shader = SkShader::CreateBitmapShader(bitmap,
    656                                                     SkShader::kClamp_TileMode,
    657                                                     SkShader::kClamp_TileMode);
    658     SkSafeUnref(tmpPaint.setShader(shader));
    659 
    660     mCanvas->drawVertices(SkCanvas::kTriangles_VertexMode, ptCount, (SkPoint*)vertices,
    661                          texs, (const SkColor*)colors, NULL, indices,
    662                          indexCount, tmpPaint);
    663 }
    664 
    665 // ----------------------------------------------------------------------------
    666 // Canvas draw operations: Text
    667 // ----------------------------------------------------------------------------
    668 
    669 void SkiaCanvas::drawText(const uint16_t* text, const float* positions, int count,
    670         const SkPaint& paint, float x, float y,
    671         float boundsLeft, float boundsTop, float boundsRight, float boundsBottom,
    672         float totalAdvance) {
    673     // Set align to left for drawing, as we don't want individual
    674     // glyphs centered or right-aligned; the offset above takes
    675     // care of all alignment.
    676     SkPaint paintCopy(paint);
    677     paintCopy.setTextAlign(SkPaint::kLeft_Align);
    678 
    679     SK_COMPILE_ASSERT(sizeof(SkPoint) == sizeof(float)*2, SkPoint_is_no_longer_2_floats);
    680     mCanvas->drawPosText(text, count << 1, reinterpret_cast<const SkPoint*>(positions), paintCopy);
    681 }
    682 
    683 void SkiaCanvas::drawPosText(const uint16_t* text, const float* positions, int count, int posCount,
    684         const SkPaint& paint) {
    685     SkPoint* posPtr = posCount > 0 ? new SkPoint[posCount] : NULL;
    686     int indx;
    687     for (indx = 0; indx < posCount; indx++) {
    688         posPtr[indx].fX = positions[indx << 1];
    689         posPtr[indx].fY = positions[(indx << 1) + 1];
    690     }
    691 
    692     SkPaint paintCopy(paint);
    693     paintCopy.setTextEncoding(SkPaint::kUTF16_TextEncoding);
    694     mCanvas->drawPosText(text, count, posPtr, paintCopy);
    695 
    696     delete[] posPtr;
    697 }
    698 
    699 void SkiaCanvas::drawTextOnPath(const uint16_t* glyphs, int count, const SkPath& path,
    700         float hOffset, float vOffset, const SkPaint& paint) {
    701     mCanvas->drawTextOnPathHV(glyphs, count << 1, path, hOffset, vOffset, paint);
    702 }
    703 
    704 } // namespace android
    705