SkiaCanvas.cpp revision 0313f2680c91985f413675c283805088960b9a54
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
29namespace android {
30
31// Holds an SkCanvas reference plus additional native data.
32class SkiaCanvas : public Canvas {
33public:
34    explicit SkiaCanvas(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(SkBitmap* bitmap, bool copyState) 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 concat(const SkMatrix& matrix) override;
71    virtual void rotate(float degrees) override;
72    virtual void scale(float sx, float sy) override;
73    virtual void skew(float sx, float sy) override;
74    virtual void translate(float dx, float dy) override;
75
76    virtual bool getClipBounds(SkRect* outRect) const override;
77    virtual bool quickRejectRect(float left, float top, float right, float bottom) const override;
78    virtual bool quickRejectPath(const SkPath& path) const override;
79    virtual bool clipRect(float left, float top, float right, float bottom,
80            SkRegion::Op op) override;
81    virtual bool clipPath(const SkPath* path, SkRegion::Op op) override;
82    virtual bool clipRegion(const SkRegion* region, SkRegion::Op op) override;
83
84    virtual SkDrawFilter* getDrawFilter() override;
85    virtual void setDrawFilter(SkDrawFilter* drawFilter) override;
86
87    virtual void drawColor(int color, SkXfermode::Mode mode) override;
88    virtual void drawPaint(const SkPaint& paint) override;
89
90    virtual void drawPoint(float x, float y, const SkPaint& paint) override;
91    virtual void drawPoints(const float* points, int count, const SkPaint& paint) override;
92    virtual void drawLine(float startX, float startY, float stopX, float stopY,
93            const SkPaint& paint) override;
94    virtual void drawLines(const float* points, int count, const SkPaint& paint) override;
95    virtual void drawRect(float left, float top, float right, float bottom,
96            const SkPaint& paint) override;
97    virtual void drawRoundRect(float left, float top, float right, float bottom,
98            float rx, float ry, const SkPaint& paint) override;
99    virtual void drawCircle(float x, float y, float radius, const SkPaint& paint) override;
100    virtual void drawOval(float left, float top, float right, float bottom,
101            const SkPaint& paint) override;
102    virtual void drawArc(float left, float top, float right, float bottom,
103            float startAngle, float sweepAngle, bool useCenter, const SkPaint& paint) override;
104    virtual void drawPath(const SkPath& path, const SkPaint& paint) override;
105    virtual void drawVertices(SkCanvas::VertexMode vertexMode, int vertexCount,
106            const float* verts, const float* tex, const int* colors,
107            const uint16_t* indices, int indexCount, const SkPaint& paint) override;
108
109    virtual void drawBitmap(const SkBitmap& bitmap, float left, float top,
110            const SkPaint* paint) override;
111    virtual void drawBitmap(const SkBitmap& bitmap, const SkMatrix& matrix,
112            const SkPaint* paint) override;
113    virtual void drawBitmap(const SkBitmap& bitmap, float srcLeft, float srcTop,
114            float srcRight, float srcBottom, float dstLeft, float dstTop,
115            float dstRight, float dstBottom, const SkPaint* paint) override;
116    virtual void drawBitmapMesh(const SkBitmap& bitmap, int meshWidth, int meshHeight,
117            const float* vertices, const int* colors, const SkPaint* paint) override;
118
119    virtual void drawText(const uint16_t* text, const float* positions, int count,
120            const SkPaint& paint, float x, float y,
121            float boundsLeft, float boundsTop, float boundsRight, float boundsBottom,
122            float totalAdvance) override;
123    virtual void drawPosText(const uint16_t* text, const float* positions, int count,
124            int posCount, const SkPaint& paint) override;
125    virtual void drawTextOnPath(const uint16_t* glyphs, int count, const SkPath& path,
126            float hOffset, float vOffset, const SkPaint& paint) override;
127
128    virtual bool drawTextAbsolutePos() const  override { return true; }
129
130private:
131    struct SaveRec {
132        int                 saveCount;
133        SkCanvas::SaveFlags saveFlags;
134    };
135
136    void recordPartialSave(SkCanvas::SaveFlags flags);
137    void saveClipsForFrame(SkTArray<SkClipStack::Element>& clips, int frameSaveCount);
138    void applyClips(const SkTArray<SkClipStack::Element>& clips);
139
140    void drawPoints(const float* points, int count, const SkPaint& paint,
141                    SkCanvas::PointMode mode);
142    void drawTextDecorations(float x, float y, float length, const SkPaint& paint);
143
144    SkAutoTUnref<SkCanvas> mCanvas;
145    SkAutoTDelete<SkDeque> mSaveStack; // lazily allocated, tracks partial saves.
146};
147
148// Construct an SkCanvas from the bitmap.
149static SkCanvas* createCanvas(SkBitmap* bitmap) {
150    if (bitmap) {
151        return SkNEW_ARGS(SkCanvas, (*bitmap));
152    }
153
154    // Create an empty bitmap device to prevent callers from crashing
155    // if they attempt to draw into this canvas.
156    SkBitmap emptyBitmap;
157    return new SkCanvas(emptyBitmap);
158}
159
160Canvas* Canvas::create_canvas(SkBitmap* bitmap) {
161    return new SkiaCanvas(bitmap);
162}
163
164Canvas* Canvas::create_canvas(SkCanvas* skiaCanvas) {
165    return new SkiaCanvas(skiaCanvas);
166}
167
168SkiaCanvas::SkiaCanvas(SkBitmap* bitmap) {
169    mCanvas.reset(createCanvas(bitmap));
170}
171
172// ----------------------------------------------------------------------------
173// Canvas state operations: Replace Bitmap
174// ----------------------------------------------------------------------------
175
176class ClipCopier : public SkCanvas::ClipVisitor {
177public:
178    ClipCopier(SkCanvas* dstCanvas) : m_dstCanvas(dstCanvas) {}
179
180    virtual void clipRect(const SkRect& rect, SkRegion::Op op, bool antialias) {
181        m_dstCanvas->clipRect(rect, op, antialias);
182    }
183    virtual void clipRRect(const SkRRect& rrect, SkRegion::Op op, bool antialias) {
184        m_dstCanvas->clipRRect(rrect, op, antialias);
185    }
186    virtual void clipPath(const SkPath& path, SkRegion::Op op, bool antialias) {
187        m_dstCanvas->clipPath(path, op, antialias);
188    }
189
190private:
191    SkCanvas* m_dstCanvas;
192};
193
194void SkiaCanvas::setBitmap(SkBitmap* bitmap, bool copyState) {
195    SkCanvas* newCanvas = createCanvas(bitmap);
196    SkASSERT(newCanvas);
197
198    if (copyState) {
199        // Copy the canvas matrix & clip state.
200        newCanvas->setMatrix(mCanvas->getTotalMatrix());
201        if (NULL != mCanvas->getDevice() && NULL != newCanvas->getDevice()) {
202            ClipCopier copier(newCanvas);
203            mCanvas->replayClips(&copier);
204        }
205    }
206
207    // unrefs the existing canvas
208    mCanvas.reset(newCanvas);
209
210    // clean up the old save stack
211    mSaveStack.reset(NULL);
212}
213
214// ----------------------------------------------------------------------------
215// Canvas state operations
216// ----------------------------------------------------------------------------
217
218bool SkiaCanvas::isOpaque() {
219    return mCanvas->getDevice()->accessBitmap(false).isOpaque();
220}
221
222int SkiaCanvas::width() {
223    return mCanvas->getBaseLayerSize().width();
224}
225
226int SkiaCanvas::height() {
227    return mCanvas->getBaseLayerSize().height();
228}
229
230// ----------------------------------------------------------------------------
231// Canvas state operations: Save (layer)
232// ----------------------------------------------------------------------------
233
234int SkiaCanvas::getSaveCount() const {
235    return mCanvas->getSaveCount();
236}
237
238int SkiaCanvas::save(SkCanvas::SaveFlags flags) {
239    int count = mCanvas->save();
240    recordPartialSave(flags);
241    return count;
242}
243
244void SkiaCanvas::restore() {
245    const SaveRec* rec = (NULL == mSaveStack.get())
246            ? NULL
247            : static_cast<SaveRec*>(mSaveStack->back());
248    int currentSaveCount = mCanvas->getSaveCount() - 1;
249    SkASSERT(NULL == rec || currentSaveCount >= rec->saveCount);
250
251    if (NULL == rec || rec->saveCount != currentSaveCount) {
252        // Fast path - no record for this frame.
253        mCanvas->restore();
254        return;
255    }
256
257    bool preserveMatrix = !(rec->saveFlags & SkCanvas::kMatrix_SaveFlag);
258    bool preserveClip   = !(rec->saveFlags & SkCanvas::kClip_SaveFlag);
259
260    SkMatrix savedMatrix;
261    if (preserveMatrix) {
262        savedMatrix = mCanvas->getTotalMatrix();
263    }
264
265    SkTArray<SkClipStack::Element> savedClips;
266    if (preserveClip) {
267        saveClipsForFrame(savedClips, currentSaveCount);
268    }
269
270    mCanvas->restore();
271
272    if (preserveMatrix) {
273        mCanvas->setMatrix(savedMatrix);
274    }
275
276    if (preserveClip && !savedClips.empty()) {
277        applyClips(savedClips);
278    }
279
280    mSaveStack->pop_back();
281}
282
283void SkiaCanvas::restoreToCount(int restoreCount) {
284    while (mCanvas->getSaveCount() > restoreCount) {
285        this->restore();
286    }
287}
288
289int SkiaCanvas::saveLayer(float left, float top, float right, float bottom,
290            const SkPaint* paint, SkCanvas::SaveFlags flags) {
291    SkRect bounds = SkRect::MakeLTRB(left, top, right, bottom);
292    int count = mCanvas->saveLayer(&bounds, paint, flags | SkCanvas::kMatrixClip_SaveFlag);
293    recordPartialSave(flags);
294    return count;
295}
296
297int SkiaCanvas::saveLayerAlpha(float left, float top, float right, float bottom,
298        int alpha, SkCanvas::SaveFlags flags) {
299    SkRect bounds = SkRect::MakeLTRB(left, top, right, bottom);
300    int count = mCanvas->saveLayerAlpha(&bounds, alpha, flags | SkCanvas::kMatrixClip_SaveFlag);
301    recordPartialSave(flags);
302    return count;
303}
304
305// ----------------------------------------------------------------------------
306// functions to emulate legacy SaveFlags (i.e. independent matrix/clip flags)
307// ----------------------------------------------------------------------------
308
309void SkiaCanvas::recordPartialSave(SkCanvas::SaveFlags flags) {
310    // A partial save is a save operation which doesn't capture the full canvas state.
311    // (either kMatrix_SaveFlags or kClip_SaveFlag is missing).
312
313    // Mask-out non canvas state bits.
314    flags = static_cast<SkCanvas::SaveFlags>(flags & SkCanvas::kMatrixClip_SaveFlag);
315
316    if (SkCanvas::kMatrixClip_SaveFlag == flags) {
317        // not a partial save.
318        return;
319    }
320
321    if (NULL == mSaveStack.get()) {
322        mSaveStack.reset(SkNEW_ARGS(SkDeque, (sizeof(struct SaveRec), 8)));
323    }
324
325    SaveRec* rec = static_cast<SaveRec*>(mSaveStack->push_back());
326    // Store the save counter in the SkClipStack domain.
327    // (0-based, equal to the number of save ops on the stack).
328    rec->saveCount = mCanvas->getSaveCount() - 1;
329    rec->saveFlags = flags;
330}
331
332void SkiaCanvas::saveClipsForFrame(SkTArray<SkClipStack::Element>& clips, int frameSaveCount) {
333    SkClipStack::Iter clipIterator(*mCanvas->getClipStack(),
334                                   SkClipStack::Iter::kTop_IterStart);
335    while (const SkClipStack::Element* elem = clipIterator.next()) {
336        if (elem->getSaveCount() < frameSaveCount) {
337            // done with the current frame.
338            break;
339        }
340        SkASSERT(elem->getSaveCount() == frameSaveCount);
341        clips.push_back(*elem);
342    }
343}
344
345void SkiaCanvas::applyClips(const SkTArray<SkClipStack::Element>& clips) {
346    ClipCopier clipCopier(mCanvas);
347
348    // The clip stack stores clips in device space.
349    SkMatrix origMatrix = mCanvas->getTotalMatrix();
350    mCanvas->resetMatrix();
351
352    // We pushed the clips in reverse order.
353    for (int i = clips.count() - 1; i >= 0; --i) {
354        clips[i].replay(&clipCopier);
355    }
356
357    mCanvas->setMatrix(origMatrix);
358}
359
360// ----------------------------------------------------------------------------
361// Canvas state operations: Matrix
362// ----------------------------------------------------------------------------
363
364void SkiaCanvas::getMatrix(SkMatrix* outMatrix) const {
365    *outMatrix = mCanvas->getTotalMatrix();
366}
367
368void SkiaCanvas::setMatrix(const SkMatrix& matrix) {
369    mCanvas->setMatrix(matrix);
370}
371
372void SkiaCanvas::concat(const SkMatrix& matrix) {
373    mCanvas->concat(matrix);
374}
375
376void SkiaCanvas::rotate(float degrees) {
377    mCanvas->rotate(degrees);
378}
379
380void SkiaCanvas::scale(float sx, float sy) {
381    mCanvas->scale(sx, sy);
382}
383
384void SkiaCanvas::skew(float sx, float sy) {
385    mCanvas->skew(sx, sy);
386}
387
388void SkiaCanvas::translate(float dx, float dy) {
389    mCanvas->translate(dx, dy);
390}
391
392// ----------------------------------------------------------------------------
393// Canvas state operations: Clips
394// ----------------------------------------------------------------------------
395
396// This function is a mirror of SkCanvas::getClipBounds except that it does
397// not outset the edge of the clip to account for anti-aliasing. There is
398// a skia bug to investigate pushing this logic into back into skia.
399// (see https://code.google.com/p/skia/issues/detail?id=1303)
400bool SkiaCanvas::getClipBounds(SkRect* outRect) const {
401    SkIRect ibounds;
402    if (!mCanvas->getClipDeviceBounds(&ibounds)) {
403        return false;
404    }
405
406    SkMatrix inverse;
407    // if we can't invert the CTM, we can't return local clip bounds
408    if (!mCanvas->getTotalMatrix().invert(&inverse)) {
409        if (outRect) {
410            outRect->setEmpty();
411        }
412        return false;
413    }
414
415    if (NULL != outRect) {
416        SkRect r = SkRect::Make(ibounds);
417        inverse.mapRect(outRect, r);
418    }
419    return true;
420}
421
422bool SkiaCanvas::quickRejectRect(float left, float top, float right, float bottom) const {
423    SkRect bounds = SkRect::MakeLTRB(left, top, right, bottom);
424    return mCanvas->quickReject(bounds);
425}
426
427bool SkiaCanvas::quickRejectPath(const SkPath& path) const {
428    return mCanvas->quickReject(path);
429}
430
431bool SkiaCanvas::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {
432    SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
433    mCanvas->clipRect(rect, op);
434    return mCanvas->isClipEmpty();
435}
436
437bool SkiaCanvas::clipPath(const SkPath* path, SkRegion::Op op) {
438    mCanvas->clipPath(*path, op);
439    return mCanvas->isClipEmpty();
440}
441
442bool SkiaCanvas::clipRegion(const SkRegion* region, SkRegion::Op op) {
443    SkPath rgnPath;
444    if (region->getBoundaryPath(&rgnPath)) {
445        // The region is specified in device space.
446        SkMatrix savedMatrix = mCanvas->getTotalMatrix();
447        mCanvas->resetMatrix();
448        mCanvas->clipPath(rgnPath, op);
449        mCanvas->setMatrix(savedMatrix);
450    } else {
451        mCanvas->clipRect(SkRect::MakeEmpty(), op);
452    }
453    return mCanvas->isClipEmpty();
454}
455
456// ----------------------------------------------------------------------------
457// Canvas state operations: Filters
458// ----------------------------------------------------------------------------
459
460SkDrawFilter* SkiaCanvas::getDrawFilter() {
461    return mCanvas->getDrawFilter();
462}
463
464void SkiaCanvas::setDrawFilter(SkDrawFilter* drawFilter) {
465    mCanvas->setDrawFilter(drawFilter);
466}
467
468// ----------------------------------------------------------------------------
469// Canvas draw operations
470// ----------------------------------------------------------------------------
471
472void SkiaCanvas::drawColor(int color, SkXfermode::Mode mode) {
473    mCanvas->drawColor(color, mode);
474}
475
476void SkiaCanvas::drawPaint(const SkPaint& paint) {
477    mCanvas->drawPaint(paint);
478}
479
480// ----------------------------------------------------------------------------
481// Canvas draw operations: Geometry
482// ----------------------------------------------------------------------------
483
484void SkiaCanvas::drawPoints(const float* points, int count, const SkPaint& paint,
485                            SkCanvas::PointMode mode) {
486    // convert the floats into SkPoints
487    count >>= 1;    // now it is the number of points
488    SkAutoSTMalloc<32, SkPoint> storage(count);
489    SkPoint* pts = storage.get();
490    for (int i = 0; i < count; i++) {
491        pts[i].set(points[0], points[1]);
492        points += 2;
493    }
494    mCanvas->drawPoints(mode, count, pts, paint);
495}
496
497
498void SkiaCanvas::drawPoint(float x, float y, const SkPaint& paint) {
499    mCanvas->drawPoint(x, y, paint);
500}
501
502void SkiaCanvas::drawPoints(const float* points, int count, const SkPaint& paint) {
503    this->drawPoints(points, count, paint, SkCanvas::kPoints_PointMode);
504}
505
506void SkiaCanvas::drawLine(float startX, float startY, float stopX, float stopY,
507                          const SkPaint& paint) {
508    mCanvas->drawLine(startX, startY, stopX, stopY, paint);
509}
510
511void SkiaCanvas::drawLines(const float* points, int count, const SkPaint& paint) {
512    this->drawPoints(points, count, paint, SkCanvas::kLines_PointMode);
513}
514
515void SkiaCanvas::drawRect(float left, float top, float right, float bottom,
516        const SkPaint& paint) {
517    mCanvas->drawRectCoords(left, top, right, bottom, paint);
518
519}
520
521void SkiaCanvas::drawRoundRect(float left, float top, float right, float bottom,
522        float rx, float ry, const SkPaint& paint) {
523    SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
524    mCanvas->drawRoundRect(rect, rx, ry, paint);
525}
526
527void SkiaCanvas::drawCircle(float x, float y, float radius, const SkPaint& paint) {
528    mCanvas->drawCircle(x, y, radius, paint);
529}
530
531void SkiaCanvas::drawOval(float left, float top, float right, float bottom, const SkPaint& paint) {
532    SkRect oval = SkRect::MakeLTRB(left, top, right, bottom);
533    mCanvas->drawOval(oval, paint);
534}
535
536void SkiaCanvas::drawArc(float left, float top, float right, float bottom,
537        float startAngle, float sweepAngle, bool useCenter, const SkPaint& paint) {
538    SkRect arc = SkRect::MakeLTRB(left, top, right, bottom);
539    mCanvas->drawArc(arc, startAngle, sweepAngle, useCenter, paint);
540}
541
542void SkiaCanvas::drawPath(const SkPath& path, const SkPaint& paint) {
543    mCanvas->drawPath(path, paint);
544}
545
546void SkiaCanvas::drawVertices(SkCanvas::VertexMode vertexMode, int vertexCount,
547                              const float* verts, const float* texs, const int* colors,
548                              const uint16_t* indices, int indexCount, const SkPaint& paint) {
549#ifndef SK_SCALAR_IS_FLOAT
550    SkDEBUGFAIL("SkScalar must be a float for these conversions to be valid");
551#endif
552    const int ptCount = vertexCount >> 1;
553    mCanvas->drawVertices(vertexMode, ptCount, (SkPoint*)verts, (SkPoint*)texs,
554                          (SkColor*)colors, NULL, indices, indexCount, paint);
555}
556
557// ----------------------------------------------------------------------------
558// Canvas draw operations: Bitmaps
559// ----------------------------------------------------------------------------
560
561void SkiaCanvas::drawBitmap(const SkBitmap& bitmap, float left, float top, const SkPaint* paint) {
562    mCanvas->drawBitmap(bitmap, left, top, paint);
563}
564
565void SkiaCanvas::drawBitmap(const SkBitmap& bitmap, const SkMatrix& matrix, const SkPaint* paint) {
566    SkAutoCanvasRestore acr(mCanvas, true);
567    mCanvas->concat(matrix);
568    mCanvas->drawBitmap(bitmap, 0, 0, paint);
569}
570
571void SkiaCanvas::drawBitmap(const SkBitmap& bitmap, float srcLeft, float srcTop,
572                            float srcRight, float srcBottom, float dstLeft, float dstTop,
573                            float dstRight, float dstBottom, const SkPaint* paint) {
574    SkRect srcRect = SkRect::MakeLTRB(srcLeft, srcTop, srcRight, srcBottom);
575    SkRect dstRect = SkRect::MakeLTRB(dstLeft, dstTop, dstRight, dstBottom);
576    mCanvas->drawBitmapRectToRect(bitmap, &srcRect, dstRect, paint);
577}
578
579void SkiaCanvas::drawBitmapMesh(const SkBitmap& bitmap, int meshWidth, int meshHeight,
580        const float* vertices, const int* colors, const SkPaint* paint) {
581
582    const int ptCount = (meshWidth + 1) * (meshHeight + 1);
583    const int indexCount = meshWidth * meshHeight * 6;
584
585    /*  Our temp storage holds 2 or 3 arrays.
586        texture points [ptCount * sizeof(SkPoint)]
587        optionally vertex points [ptCount * sizeof(SkPoint)] if we need a
588            copy to convert from float to fixed
589        indices [ptCount * sizeof(uint16_t)]
590    */
591    ssize_t storageSize = ptCount * sizeof(SkPoint); // texs[]
592    storageSize += indexCount * sizeof(uint16_t);  // indices[]
593
594
595#ifndef SK_SCALAR_IS_FLOAT
596    SkDEBUGFAIL("SkScalar must be a float for these conversions to be valid");
597#endif
598    SkAutoMalloc storage(storageSize);
599    SkPoint* texs = (SkPoint*)storage.get();
600    uint16_t* indices = (uint16_t*)(texs + ptCount);
601
602    // cons up texture coordinates and indices
603    {
604        const SkScalar w = SkIntToScalar(bitmap.width());
605        const SkScalar h = SkIntToScalar(bitmap.height());
606        const SkScalar dx = w / meshWidth;
607        const SkScalar dy = h / meshHeight;
608
609        SkPoint* texsPtr = texs;
610        SkScalar y = 0;
611        for (int i = 0; i <= meshHeight; i++) {
612            if (i == meshHeight) {
613                y = h;  // to ensure numerically we hit h exactly
614            }
615            SkScalar x = 0;
616            for (int j = 0; j < meshWidth; j++) {
617                texsPtr->set(x, y);
618                texsPtr += 1;
619                x += dx;
620            }
621            texsPtr->set(w, y);
622            texsPtr += 1;
623            y += dy;
624        }
625        SkASSERT(texsPtr - texs == ptCount);
626    }
627
628    // cons up indices
629    {
630        uint16_t* indexPtr = indices;
631        int index = 0;
632        for (int i = 0; i < meshHeight; i++) {
633            for (int j = 0; j < meshWidth; j++) {
634                // lower-left triangle
635                *indexPtr++ = index;
636                *indexPtr++ = index + meshWidth + 1;
637                *indexPtr++ = index + meshWidth + 2;
638                // upper-right triangle
639                *indexPtr++ = index;
640                *indexPtr++ = index + meshWidth + 2;
641                *indexPtr++ = index + 1;
642                // bump to the next cell
643                index += 1;
644            }
645            // bump to the next row
646            index += 1;
647        }
648        SkASSERT(indexPtr - indices == indexCount);
649        SkASSERT((char*)indexPtr - (char*)storage.get() == storageSize);
650    }
651
652    // double-check that we have legal indices
653#ifdef SK_DEBUG
654    {
655        for (int i = 0; i < indexCount; i++) {
656            SkASSERT((unsigned)indices[i] < (unsigned)ptCount);
657        }
658    }
659#endif
660
661    // cons-up a shader for the bitmap
662    SkPaint tmpPaint;
663    if (paint) {
664        tmpPaint = *paint;
665    }
666    SkShader* shader = SkShader::CreateBitmapShader(bitmap,
667                                                    SkShader::kClamp_TileMode,
668                                                    SkShader::kClamp_TileMode);
669    SkSafeUnref(tmpPaint.setShader(shader));
670
671    mCanvas->drawVertices(SkCanvas::kTriangles_VertexMode, ptCount, (SkPoint*)vertices,
672                         texs, (const SkColor*)colors, NULL, indices,
673                         indexCount, tmpPaint);
674}
675
676// ----------------------------------------------------------------------------
677// Canvas draw operations: Text
678// ----------------------------------------------------------------------------
679
680void SkiaCanvas::drawText(const uint16_t* text, const float* positions, int count,
681        const SkPaint& paint, float x, float y,
682        float boundsLeft, float boundsTop, float boundsRight, float boundsBottom,
683        float totalAdvance) {
684    // Set align to left for drawing, as we don't want individual
685    // glyphs centered or right-aligned; the offset above takes
686    // care of all alignment.
687    SkPaint paintCopy(paint);
688    paintCopy.setTextAlign(SkPaint::kLeft_Align);
689
690    SK_COMPILE_ASSERT(sizeof(SkPoint) == sizeof(float)*2, SkPoint_is_no_longer_2_floats);
691    mCanvas->drawPosText(text, count << 1, reinterpret_cast<const SkPoint*>(positions), paintCopy);
692}
693
694void SkiaCanvas::drawPosText(const uint16_t* text, const float* positions, int count, int posCount,
695        const SkPaint& paint) {
696    SkPoint* posPtr = posCount > 0 ? new SkPoint[posCount] : NULL;
697    int indx;
698    for (indx = 0; indx < posCount; indx++) {
699        posPtr[indx].fX = positions[indx << 1];
700        posPtr[indx].fY = positions[(indx << 1) + 1];
701    }
702
703    SkPaint paintCopy(paint);
704    paintCopy.setTextEncoding(SkPaint::kUTF16_TextEncoding);
705    mCanvas->drawPosText(text, count, posPtr, paintCopy);
706
707    delete[] posPtr;
708}
709
710void SkiaCanvas::drawTextOnPath(const uint16_t* glyphs, int count, const SkPath& path,
711        float hOffset, float vOffset, const SkPaint& paint) {
712    mCanvas->drawTextOnPathHV(glyphs, count, path, hOffset, vOffset, paint);
713}
714
715} // namespace android
716