GrContext.cpp revision 5b3e890c376f2211218c43edd11939cfc78fd60a 
1
2/*
3 * Copyright 2011 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#include "GrContext.h"
11
12#include "effects/GrConvolutionEffect.h"
13#include "effects/GrSingleTextureEffect.h"
14#include "effects/GrConfigConversionEffect.h"
15
16#include "GrBufferAllocPool.h"
17#include "GrGpu.h"
18#include "GrIndexBuffer.h"
19#include "GrInOrderDrawBuffer.h"
20#include "GrPathRenderer.h"
21#include "GrPathUtils.h"
22#include "GrResourceCache.h"
23#include "GrSoftwarePathRenderer.h"
24#include "GrStencilBuffer.h"
25#include "GrTextStrike.h"
26#include "SkTLazy.h"
27#include "SkTLS.h"
28#include "SkTrace.h"
29
30SK_DEFINE_INST_COUNT(GrContext)
31SK_DEFINE_INST_COUNT(GrDrawState)
32
33// It can be useful to set this to kNo_BufferedDraw to test whether a bug is caused by using the
34// InOrderDrawBuffer, to compare performance of using/not using InOrderDrawBuffer, or to make
35// debugging easier.
36#define DEFAULT_BUFFERING (GR_DISABLE_DRAW_BUFFERING ? kNo_BufferedDraw : kYes_BufferedDraw)
37
38#define MAX_BLUR_SIGMA 4.0f
39
40// When we're using coverage AA but the blend is incompatible (given gpu
41// limitations) should we disable AA or draw wrong?
42#define DISABLE_COVERAGE_AA_FOR_BLEND 1
43
44#if GR_DEBUG
45    // change this to a 1 to see notifications when partial coverage fails
46    #define GR_DEBUG_PARTIAL_COVERAGE_CHECK 0
47#else
48    #define GR_DEBUG_PARTIAL_COVERAGE_CHECK 0
49#endif
50
51static const size_t MAX_TEXTURE_CACHE_COUNT = 256;
52static const size_t MAX_TEXTURE_CACHE_BYTES = 16 * 1024 * 1024;
53
54static const size_t DRAW_BUFFER_VBPOOL_BUFFER_SIZE = 1 << 15;
55static const int DRAW_BUFFER_VBPOOL_PREALLOC_BUFFERS = 4;
56
57static const size_t DRAW_BUFFER_IBPOOL_BUFFER_SIZE = 1 << 11;
58static const int DRAW_BUFFER_IBPOOL_PREALLOC_BUFFERS = 4;
59
60#define ASSERT_OWNED_RESOURCE(R) GrAssert(!(R) || (R)->getContext() == this)
61
62GrContext* GrContext::Create(GrEngine engine,
63                             GrPlatform3DContext context3D) {
64    GrContext* ctx = NULL;
65    GrGpu* fGpu = GrGpu::Create(engine, context3D);
66    if (NULL != fGpu) {
67        ctx = SkNEW_ARGS(GrContext, (fGpu));
68        fGpu->unref();
69    }
70    return ctx;
71}
72
73namespace {
74void* CreateThreadInstanceCount() {
75    return SkNEW_ARGS(int, (0));
76}
77void DeleteThreadInstanceCount(void* v) {
78    delete reinterpret_cast<int*>(v);
79}
80#define THREAD_INSTANCE_COUNT                                               \
81    (*reinterpret_cast<int*>(SkTLS::Get(CreateThreadInstanceCount,          \
82                                        DeleteThreadInstanceCount)))
83
84}
85
86int GrContext::GetThreadInstanceCount() {
87    return THREAD_INSTANCE_COUNT;
88}
89
90GrContext::~GrContext() {
91    for (int i = 0; i < fCleanUpData.count(); ++i) {
92        (*fCleanUpData[i].fFunc)(this, fCleanUpData[i].fInfo);
93    }
94
95    this->flush();
96
97    // Since the gpu can hold scratch textures, give it a chance to let go
98    // of them before freeing the texture cache
99    fGpu->purgeResources();
100
101    delete fTextureCache;
102    fTextureCache = NULL;
103    delete fFontCache;
104    delete fDrawBuffer;
105    delete fDrawBufferVBAllocPool;
106    delete fDrawBufferIBAllocPool;
107
108    fAARectRenderer->unref();
109
110    fGpu->unref();
111    GrSafeUnref(fPathRendererChain);
112    GrSafeUnref(fSoftwarePathRenderer);
113    fDrawState->unref();
114
115    --THREAD_INSTANCE_COUNT;
116}
117
118void GrContext::contextLost() {
119    contextDestroyed();
120    this->setupDrawBuffer();
121}
122
123void GrContext::contextDestroyed() {
124    // abandon first to so destructors
125    // don't try to free the resources in the API.
126    fGpu->abandonResources();
127
128    // a path renderer may be holding onto resources that
129    // are now unusable
130    GrSafeSetNull(fPathRendererChain);
131    GrSafeSetNull(fSoftwarePathRenderer);
132
133    delete fDrawBuffer;
134    fDrawBuffer = NULL;
135
136    delete fDrawBufferVBAllocPool;
137    fDrawBufferVBAllocPool = NULL;
138
139    delete fDrawBufferIBAllocPool;
140    fDrawBufferIBAllocPool = NULL;
141
142    fAARectRenderer->reset();
143
144    fTextureCache->purgeAllUnlocked();
145    fFontCache->freeAll();
146    fGpu->markContextDirty();
147}
148
149void GrContext::resetContext() {
150    fGpu->markContextDirty();
151}
152
153void GrContext::freeGpuResources() {
154    this->flush();
155
156    fGpu->purgeResources();
157
158    fAARectRenderer->reset();
159
160    fTextureCache->purgeAllUnlocked();
161    fFontCache->freeAll();
162    // a path renderer may be holding onto resources
163    GrSafeSetNull(fPathRendererChain);
164    GrSafeSetNull(fSoftwarePathRenderer);
165}
166
167size_t GrContext::getGpuTextureCacheBytes() const {
168  return fTextureCache->getCachedResourceBytes();
169}
170
171////////////////////////////////////////////////////////////////////////////////
172
173namespace {
174
175void scale_rect(SkRect* rect, float xScale, float yScale) {
176    rect->fLeft = SkScalarMul(rect->fLeft, SkFloatToScalar(xScale));
177    rect->fTop = SkScalarMul(rect->fTop, SkFloatToScalar(yScale));
178    rect->fRight = SkScalarMul(rect->fRight, SkFloatToScalar(xScale));
179    rect->fBottom = SkScalarMul(rect->fBottom, SkFloatToScalar(yScale));
180}
181
182float adjust_sigma(float sigma, int *scaleFactor, int *radius) {
183    *scaleFactor = 1;
184    while (sigma > MAX_BLUR_SIGMA) {
185        *scaleFactor *= 2;
186        sigma *= 0.5f;
187    }
188    *radius = static_cast<int>(ceilf(sigma * 3.0f));
189    GrAssert(*radius <= GrConvolutionEffect::kMaxKernelRadius);
190    return sigma;
191}
192
193void convolve_gaussian(GrDrawTarget* target,
194                       GrTexture* texture,
195                       const SkRect& rect,
196                       float sigma,
197                       int radius,
198                       Gr1DKernelEffect::Direction direction) {
199    GrRenderTarget* rt = target->drawState()->getRenderTarget();
200    GrDrawTarget::AutoStateRestore asr(target, GrDrawTarget::kReset_ASRInit);
201    GrDrawState* drawState = target->drawState();
202    drawState->setRenderTarget(rt);
203    GrMatrix sampleM;
204    sampleM.setIDiv(texture->width(), texture->height());
205    drawState->sampler(0)->reset(sampleM);
206    SkAutoTUnref<GrConvolutionEffect> conv(SkNEW_ARGS(GrConvolutionEffect,
207                                                      (texture, direction, radius,
208                                                       sigma)));
209    drawState->sampler(0)->setCustomStage(conv);
210    target->drawSimpleRect(rect, NULL);
211}
212
213}
214
215
216GrTexture* GrContext::findTexture(const GrCacheKey& key) {
217    return static_cast<GrTexture*>(fTextureCache->find(key.key()));
218}
219
220GrTexture* GrContext::findTexture(const GrTextureDesc& desc,
221                                  const GrCacheData& cacheData,
222                                  const GrTextureParams* params) {
223    GrResourceKey resourceKey = GrTexture::ComputeKey(fGpu, params, desc, cacheData, false);
224    GrResource* resource = fTextureCache->find(resourceKey);
225    return static_cast<GrTexture*>(resource);
226}
227
228bool GrContext::isTextureInCache(const GrTextureDesc& desc,
229                                 const GrCacheData& cacheData,
230                                 const GrTextureParams* params) const {
231    GrResourceKey resourceKey = GrTexture::ComputeKey(fGpu, params, desc, cacheData, false);
232    return fTextureCache->hasKey(resourceKey);
233}
234
235void GrContext::addStencilBuffer(GrStencilBuffer* sb) {
236    ASSERT_OWNED_RESOURCE(sb);
237
238    GrResourceKey resourceKey = GrStencilBuffer::ComputeKey(sb->width(),
239                                                            sb->height(),
240                                                            sb->numSamples());
241    fTextureCache->create(resourceKey, sb);
242}
243
244GrStencilBuffer* GrContext::findStencilBuffer(int width, int height,
245                                              int sampleCnt) {
246    GrResourceKey resourceKey = GrStencilBuffer::ComputeKey(width,
247                                                            height,
248                                                            sampleCnt);
249    GrResource* resource = fTextureCache->find(resourceKey);
250    return static_cast<GrStencilBuffer*>(resource);
251}
252
253static void stretchImage(void* dst,
254                         int dstW,
255                         int dstH,
256                         void* src,
257                         int srcW,
258                         int srcH,
259                         int bpp) {
260    GrFixed dx = (srcW << 16) / dstW;
261    GrFixed dy = (srcH << 16) / dstH;
262
263    GrFixed y = dy >> 1;
264
265    int dstXLimit = dstW*bpp;
266    for (int j = 0; j < dstH; ++j) {
267        GrFixed x = dx >> 1;
268        void* srcRow = (uint8_t*)src + (y>>16)*srcW*bpp;
269        void* dstRow = (uint8_t*)dst + j*dstW*bpp;
270        for (int i = 0; i < dstXLimit; i += bpp) {
271            memcpy((uint8_t*) dstRow + i,
272                   (uint8_t*) srcRow + (x>>16)*bpp,
273                   bpp);
274            x += dx;
275        }
276        y += dy;
277    }
278}
279
280// The desired texture is NPOT and tiled but that isn't supported by
281// the current hardware. Resize the texture to be a POT
282GrTexture* GrContext::createResizedTexture(const GrTextureDesc& desc,
283                                           const GrCacheData& cacheData,
284                                           void* srcData,
285                                           size_t rowBytes,
286                                           bool needsFiltering) {
287    GrTexture* clampedTexture = this->findTexture(desc, cacheData, NULL);
288    if (NULL == clampedTexture) {
289        clampedTexture = this->createTexture(NULL, desc, cacheData, srcData, rowBytes);
290
291        GrAssert(NULL != clampedTexture);
292        if (NULL == clampedTexture) {
293            return NULL;
294        }
295    }
296
297    clampedTexture->ref();
298
299    GrTextureDesc rtDesc = desc;
300    rtDesc.fFlags =  rtDesc.fFlags |
301                     kRenderTarget_GrTextureFlagBit |
302                     kNoStencil_GrTextureFlagBit;
303    rtDesc.fWidth  = GrNextPow2(GrMax(desc.fWidth, 64));
304    rtDesc.fHeight = GrNextPow2(GrMax(desc.fHeight, 64));
305
306    GrTexture* texture = fGpu->createTexture(rtDesc, NULL, 0);
307
308    if (NULL != texture) {
309        GrDrawTarget::AutoStateRestore asr(fGpu, GrDrawTarget::kReset_ASRInit);
310        GrDrawState* drawState = fGpu->drawState();
311        drawState->setRenderTarget(texture->asRenderTarget());
312
313        // if filtering is not desired then we want to ensure all
314        // texels in the resampled image are copies of texels from
315        // the original.
316        drawState->sampler(0)->reset();
317        GrTextureParams params(SkShader::kClamp_TileMode, needsFiltering);
318        drawState->createTextureEffect(0, clampedTexture, params);
319
320        static const GrVertexLayout layout =
321                            GrDrawTarget::StageTexCoordVertexLayoutBit(0,0);
322        GrDrawTarget::AutoReleaseGeometry arg(fGpu, layout, 4, 0);
323
324        if (arg.succeeded()) {
325            GrPoint* verts = (GrPoint*) arg.vertices();
326            verts[0].setIRectFan(0, 0,
327                                    texture->width(),
328                                    texture->height(),
329                                    2*sizeof(GrPoint));
330            verts[1].setIRectFan(0, 0, 1, 1, 2*sizeof(GrPoint));
331            fGpu->drawNonIndexed(kTriangleFan_GrPrimitiveType,
332                                    0, 4);
333        }
334        texture->releaseRenderTarget();
335    } else {
336        // TODO: Our CPU stretch doesn't filter. But we create separate
337        // stretched textures when the sampler state is either filtered or
338        // not. Either implement filtered stretch blit on CPU or just create
339        // one when FBO case fails.
340
341        rtDesc.fFlags = kNone_GrTextureFlags;
342        // no longer need to clamp at min RT size.
343        rtDesc.fWidth  = GrNextPow2(desc.fWidth);
344        rtDesc.fHeight = GrNextPow2(desc.fHeight);
345        int bpp = GrBytesPerPixel(desc.fConfig);
346        SkAutoSMalloc<128*128*4> stretchedPixels(bpp *
347                                                    rtDesc.fWidth *
348                                                    rtDesc.fHeight);
349        stretchImage(stretchedPixels.get(), rtDesc.fWidth, rtDesc.fHeight,
350                        srcData, desc.fWidth, desc.fHeight, bpp);
351
352        size_t stretchedRowBytes = rtDesc.fWidth * bpp;
353
354        GrTexture* texture = fGpu->createTexture(rtDesc,
355                                                    stretchedPixels.get(),
356                                                    stretchedRowBytes);
357        GrAssert(NULL != texture);
358    }
359
360    clampedTexture->unref();
361    return texture;
362}
363
364GrTexture* GrContext::createTexture(
365        const GrTextureParams* params,
366        const GrTextureDesc& desc,
367        const GrCacheData& cacheData,
368        void* srcData,
369        size_t rowBytes) {
370    SK_TRACE_EVENT0("GrContext::createAndLockTexture");
371
372#if GR_DUMP_TEXTURE_UPLOAD
373    GrPrintf("GrContext::createAndLockTexture [%d %d]\n", desc.fWidth, desc.fHeight);
374#endif
375
376    GrResourceKey resourceKey = GrTexture::ComputeKey(fGpu, params, desc, cacheData, false);
377
378    SkAutoTUnref<GrTexture> texture;
379    if (GrTexture::NeedsResizing(resourceKey)) {
380        texture.reset(this->createResizedTexture(desc, cacheData,
381                                             srcData, rowBytes,
382                                             GrTexture::NeedsFiltering(resourceKey)));
383    } else {
384        texture.reset(fGpu->createTexture(desc, srcData, rowBytes));
385    }
386
387    if (NULL != texture) {
388        fTextureCache->create(resourceKey, texture);
389    }
390
391    return texture;
392}
393
394GrTexture* GrContext::lockScratchTexture(const GrTextureDesc& inDesc,
395                                         ScratchTexMatch match) {
396    GrTextureDesc desc = inDesc;
397    GrCacheData cacheData(GrCacheData::kScratch_CacheID);
398
399    GrAssert((desc.fFlags & kRenderTarget_GrTextureFlagBit) ||
400             !(desc.fFlags & kNoStencil_GrTextureFlagBit));
401
402    if (kExact_ScratchTexMatch != match) {
403        // bin by pow2 with a reasonable min
404        static const int MIN_SIZE = 256;
405        desc.fWidth  = GrMax(MIN_SIZE, GrNextPow2(desc.fWidth));
406        desc.fHeight = GrMax(MIN_SIZE, GrNextPow2(desc.fHeight));
407    }
408
409    GrResource* resource = NULL;
410    int origWidth = desc.fWidth;
411    int origHeight = desc.fHeight;
412    bool doubledW = false;
413    bool doubledH = false;
414
415    do {
416        GrResourceKey key = GrTexture::ComputeKey(fGpu, NULL, desc, cacheData, true);
417        resource = fTextureCache->find(key);
418        // if we miss, relax the fit of the flags...
419        // then try doubling width... then height.
420        if (NULL != resource || kExact_ScratchTexMatch == match) {
421            break;
422        }
423        // We no longer try to reuse textures that were previously used as render targets in
424        // situations where no RT is needed; doing otherwise can confuse the video driver and
425        // cause significant performance problems in some cases.
426        if (desc.fFlags & kNoStencil_GrTextureFlagBit) {
427            desc.fFlags = desc.fFlags & ~kNoStencil_GrTextureFlagBit;
428        } else if (!doubledW) {
429            desc.fFlags = inDesc.fFlags;
430            desc.fWidth *= 2;
431            doubledW = true;
432        } else if (!doubledH) {
433            desc.fFlags = inDesc.fFlags;
434            desc.fWidth = origWidth;
435            desc.fHeight *= 2;
436            doubledH = true;
437        } else {
438            break;
439        }
440
441    } while (true);
442
443    if (NULL == resource) {
444        desc.fFlags = inDesc.fFlags;
445        desc.fWidth = origWidth;
446        desc.fHeight = origHeight;
447        SkAutoTUnref<GrTexture> texture(fGpu->createTexture(desc, NULL, 0));
448        if (NULL != texture) {
449            GrResourceKey key = GrTexture::ComputeKey(fGpu, NULL,
450                                                      texture->desc(),
451                                                      cacheData,
452                                                      true);
453            fTextureCache->create(key, texture);
454            resource = texture;
455        }
456    }
457
458    // If the caller gives us the same desc/sampler twice we don't want
459    // to return the same texture the second time (unless it was previously
460    // released). So make it exclusive to hide it from future searches.
461    if (NULL != resource) {
462        fTextureCache->makeExclusive(resource->getCacheEntry());
463    }
464
465    return static_cast<GrTexture*>(resource);
466}
467
468void GrContext::addExistingTextureToCache(GrTexture* texture) {
469
470    if (NULL == texture) {
471        return;
472    }
473
474    // This texture should already have a cache entry since it was once
475    // attached
476    GrAssert(NULL != texture->getCacheEntry());
477
478    // Conceptually, the cache entry is going to assume responsibility
479    // for the creation ref.
480    GrAssert(1 == texture->getRefCnt());
481
482    // Since this texture came from an AutoScratchTexture it should
483    // still be in the exclusive pile
484    fTextureCache->makeNonExclusive(texture->getCacheEntry());
485
486    this->purgeCache();
487}
488
489
490void GrContext::unlockScratchTexture(GrTexture* texture) {
491    ASSERT_OWNED_RESOURCE(texture);
492    GrAssert(NULL != texture->getCacheEntry());
493
494    // If this is a scratch texture we detached it from the cache
495    // while it was locked (to avoid two callers simultaneously getting
496    // the same texture).
497    if (GrTexture::IsScratchTexture(texture->getCacheEntry()->key())) {
498        fTextureCache->makeNonExclusive(texture->getCacheEntry());
499    }
500
501    this->purgeCache();
502}
503
504void GrContext::purgeCache() {
505    if (NULL != fTextureCache) {
506        fTextureCache->purgeAsNeeded();
507    }
508}
509
510GrTexture* GrContext::createUncachedTexture(const GrTextureDesc& descIn,
511                                            void* srcData,
512                                            size_t rowBytes) {
513    GrTextureDesc descCopy = descIn;
514    return fGpu->createTexture(descCopy, srcData, rowBytes);
515}
516
517void GrContext::getTextureCacheLimits(int* maxTextures,
518                                      size_t* maxTextureBytes) const {
519    fTextureCache->getLimits(maxTextures, maxTextureBytes);
520}
521
522void GrContext::setTextureCacheLimits(int maxTextures, size_t maxTextureBytes) {
523    fTextureCache->setLimits(maxTextures, maxTextureBytes);
524}
525
526int GrContext::getMaxTextureSize() const {
527    return fGpu->getCaps().maxTextureSize();
528}
529
530int GrContext::getMaxRenderTargetSize() const {
531    return fGpu->getCaps().maxRenderTargetSize();
532}
533
534///////////////////////////////////////////////////////////////////////////////
535
536GrTexture* GrContext::createPlatformTexture(const GrPlatformTextureDesc& desc) {
537    return fGpu->createPlatformTexture(desc);
538}
539
540GrRenderTarget* GrContext::createPlatformRenderTarget(const GrPlatformRenderTargetDesc& desc) {
541    return fGpu->createPlatformRenderTarget(desc);
542}
543
544///////////////////////////////////////////////////////////////////////////////
545
546bool GrContext::supportsIndex8PixelConfig(const GrTextureParams* params,
547                                          int width, int height) const {
548    const GrDrawTarget::Caps& caps = fGpu->getCaps();
549    if (!caps.eightBitPaletteSupport()) {
550        return false;
551    }
552
553    bool isPow2 = GrIsPow2(width) && GrIsPow2(height);
554
555    if (!isPow2) {
556        bool tiled = NULL != params && params->isTiled();
557        if (tiled && !caps.npotTextureTileSupport()) {
558            return false;
559        }
560    }
561    return true;
562}
563
564////////////////////////////////////////////////////////////////////////////////
565
566const GrClipData* GrContext::getClip() const {
567    return fGpu->getClip();
568}
569
570void GrContext::setClip(const GrClipData* clipData) {
571    fGpu->setClip(clipData);
572
573    fDrawState->setState(GrDrawState::kClip_StateBit, !clipData->fClipStack->isWideOpen());
574}
575
576////////////////////////////////////////////////////////////////////////////////
577
578void GrContext::clear(const GrIRect* rect,
579                      const GrColor color,
580                      GrRenderTarget* target) {
581    this->prepareToDraw(NULL, DEFAULT_BUFFERING)->clear(rect, color, target);
582}
583
584void GrContext::drawPaint(const GrPaint& paint) {
585    // set rect to be big enough to fill the space, but not super-huge, so we
586    // don't overflow fixed-point implementations
587    GrRect r;
588    r.setLTRB(0, 0,
589              GrIntToScalar(getRenderTarget()->width()),
590              GrIntToScalar(getRenderTarget()->height()));
591    GrMatrix inverse;
592    SkTLazy<GrPaint> tmpPaint;
593    const GrPaint* p = &paint;
594    AutoMatrix am;
595
596    // We attempt to map r by the inverse matrix and draw that. mapRect will
597    // map the four corners and bound them with a new rect. This will not
598    // produce a correct result for some perspective matrices.
599    if (!this->getMatrix().hasPerspective()) {
600        if (!fDrawState->getViewInverse(&inverse)) {
601            GrPrintf("Could not invert matrix\n");
602            return;
603        }
604        inverse.mapRect(&r);
605    } else {
606        if (paint.hasStage()) {
607            tmpPaint.set(paint);
608            p = tmpPaint.get();
609            if (!tmpPaint.get()->preConcatSamplerMatricesWithInverse(fDrawState->getViewMatrix())) {
610                GrPrintf("Could not invert matrix\n");
611            }
612        }
613        am.set(this, GrMatrix::I());
614    }
615    // by definition this fills the entire clip, no need for AA
616    if (paint.isAntiAlias()) {
617        if (!tmpPaint.isValid()) {
618            tmpPaint.set(paint);
619            p = tmpPaint.get();
620        }
621        GrAssert(p == tmpPaint.get());
622        tmpPaint.get()->setAntiAlias(false);
623    }
624    this->drawRect(*p, r);
625}
626
627////////////////////////////////////////////////////////////////////////////////
628
629namespace {
630inline bool disable_coverage_aa_for_blend(GrDrawTarget* target) {
631    return DISABLE_COVERAGE_AA_FOR_BLEND && !target->canApplyCoverage();
632}
633}
634
635////////////////////////////////////////////////////////////////////////////////
636
637/*  create a triangle strip that strokes the specified triangle. There are 8
638 unique vertices, but we repreat the last 2 to close up. Alternatively we
639 could use an indices array, and then only send 8 verts, but not sure that
640 would be faster.
641 */
642static void setStrokeRectStrip(GrPoint verts[10], GrRect rect,
643                               GrScalar width) {
644    const GrScalar rad = GrScalarHalf(width);
645    rect.sort();
646
647    verts[0].set(rect.fLeft + rad, rect.fTop + rad);
648    verts[1].set(rect.fLeft - rad, rect.fTop - rad);
649    verts[2].set(rect.fRight - rad, rect.fTop + rad);
650    verts[3].set(rect.fRight + rad, rect.fTop - rad);
651    verts[4].set(rect.fRight - rad, rect.fBottom - rad);
652    verts[5].set(rect.fRight + rad, rect.fBottom + rad);
653    verts[6].set(rect.fLeft + rad, rect.fBottom - rad);
654    verts[7].set(rect.fLeft - rad, rect.fBottom + rad);
655    verts[8] = verts[0];
656    verts[9] = verts[1];
657}
658
659/**
660 * Returns true if the rects edges are integer-aligned.
661 */
662static bool isIRect(const GrRect& r) {
663    return GrScalarIsInt(r.fLeft) && GrScalarIsInt(r.fTop) &&
664           GrScalarIsInt(r.fRight) && GrScalarIsInt(r.fBottom);
665}
666
667static bool apply_aa_to_rect(GrDrawTarget* target,
668                             const GrRect& rect,
669                             GrScalar width,
670                             const GrMatrix* matrix,
671                             GrMatrix* combinedMatrix,
672                             GrRect* devRect,
673                             bool* useVertexCoverage) {
674    // we use a simple coverage ramp to do aa on axis-aligned rects
675    // we check if the rect will be axis-aligned, and the rect won't land on
676    // integer coords.
677
678    // we are keeping around the "tweak the alpha" trick because
679    // it is our only hope for the fixed-pipe implementation.
680    // In a shader implementation we can give a separate coverage input
681    // TODO: remove this ugliness when we drop the fixed-pipe impl
682    *useVertexCoverage = false;
683    if (!target->canTweakAlphaForCoverage()) {
684        if (disable_coverage_aa_for_blend(target)) {
685#if GR_DEBUG
686            //GrPrintf("Turning off AA to correctly apply blend.\n");
687#endif
688            return false;
689        } else {
690            *useVertexCoverage = true;
691        }
692    }
693    const GrDrawState& drawState = target->getDrawState();
694    if (drawState.getRenderTarget()->isMultisampled()) {
695        return false;
696    }
697
698    if (0 == width && target->willUseHWAALines()) {
699        return false;
700    }
701
702    if (!drawState.getViewMatrix().preservesAxisAlignment()) {
703        return false;
704    }
705
706    if (NULL != matrix &&
707        !matrix->preservesAxisAlignment()) {
708        return false;
709    }
710
711    *combinedMatrix = drawState.getViewMatrix();
712    if (NULL != matrix) {
713        combinedMatrix->preConcat(*matrix);
714        GrAssert(combinedMatrix->preservesAxisAlignment());
715    }
716
717    combinedMatrix->mapRect(devRect, rect);
718    devRect->sort();
719
720    if (width < 0) {
721        return !isIRect(*devRect);
722    } else {
723        return true;
724    }
725}
726
727void GrContext::drawRect(const GrPaint& paint,
728                         const GrRect& rect,
729                         GrScalar width,
730                         const GrMatrix* matrix) {
731    SK_TRACE_EVENT0("GrContext::drawRect");
732
733    GrDrawTarget* target = this->prepareToDraw(&paint, DEFAULT_BUFFERING);
734    GrDrawState::AutoStageDisable atr(fDrawState);
735
736    GrRect devRect = rect;
737    GrMatrix combinedMatrix;
738    bool useVertexCoverage;
739    bool needAA = paint.isAntiAlias() &&
740                  !this->getRenderTarget()->isMultisampled();
741    bool doAA = needAA && apply_aa_to_rect(target, rect, width, matrix,
742                                           &combinedMatrix, &devRect,
743                                           &useVertexCoverage);
744
745    if (doAA) {
746        GrDrawState::AutoDeviceCoordDraw adcd(target->drawState());
747        if (!adcd.succeeded()) {
748            return;
749        }
750        if (width >= 0) {
751            GrVec strokeSize;;
752            if (width > 0) {
753                strokeSize.set(width, width);
754                combinedMatrix.mapVectors(&strokeSize, 1);
755                strokeSize.setAbs(strokeSize);
756            } else {
757                strokeSize.set(GR_Scalar1, GR_Scalar1);
758            }
759            fAARectRenderer->strokeAARect(this->getGpu(), target, devRect,
760                                         strokeSize, useVertexCoverage);
761        } else {
762            fAARectRenderer->fillAARect(this->getGpu(), target,
763                                       devRect, useVertexCoverage);
764        }
765        return;
766    }
767
768    if (width >= 0) {
769        // TODO: consider making static vertex buffers for these cases.
770        // Hairline could be done by just adding closing vertex to
771        // unitSquareVertexBuffer()
772
773        static const int worstCaseVertCount = 10;
774        GrDrawTarget::AutoReleaseGeometry geo(target, 0, worstCaseVertCount, 0);
775
776        if (!geo.succeeded()) {
777            GrPrintf("Failed to get space for vertices!\n");
778            return;
779        }
780
781        GrPrimitiveType primType;
782        int vertCount;
783        GrPoint* vertex = geo.positions();
784
785        if (width > 0) {
786            vertCount = 10;
787            primType = kTriangleStrip_GrPrimitiveType;
788            setStrokeRectStrip(vertex, rect, width);
789        } else {
790            // hairline
791            vertCount = 5;
792            primType = kLineStrip_GrPrimitiveType;
793            vertex[0].set(rect.fLeft, rect.fTop);
794            vertex[1].set(rect.fRight, rect.fTop);
795            vertex[2].set(rect.fRight, rect.fBottom);
796            vertex[3].set(rect.fLeft, rect.fBottom);
797            vertex[4].set(rect.fLeft, rect.fTop);
798        }
799
800        GrDrawState::AutoViewMatrixRestore avmr;
801        if (NULL != matrix) {
802            GrDrawState* drawState = target->drawState();
803            avmr.set(drawState);
804            drawState->preConcatViewMatrix(*matrix);
805            drawState->preConcatSamplerMatrices(*matrix);
806        }
807
808        target->drawNonIndexed(primType, 0, vertCount);
809    } else {
810#if GR_STATIC_RECT_VB
811            const GrVertexBuffer* sqVB = fGpu->getUnitSquareVertexBuffer();
812            if (NULL == sqVB) {
813                GrPrintf("Failed to create static rect vb.\n");
814                return;
815            }
816            target->setVertexSourceToBuffer(0, sqVB);
817            GrDrawState* drawState = target->drawState();
818            GrDrawState::AutoViewMatrixRestore avmr(drawState);
819            GrMatrix m;
820            m.setAll(rect.width(),    0,             rect.fLeft,
821                        0,            rect.height(), rect.fTop,
822                        0,            0,             GrMatrix::I()[8]);
823
824            if (NULL != matrix) {
825                m.postConcat(*matrix);
826            }
827            drawState->preConcatViewMatrix(m);
828            drawState->preConcatSamplerMatrices(m);
829
830            target->drawNonIndexed(kTriangleFan_GrPrimitiveType, 0, 4);
831#else
832            target->drawSimpleRect(rect, matrix);
833#endif
834    }
835}
836
837void GrContext::drawRectToRect(const GrPaint& paint,
838                               const GrRect& dstRect,
839                               const GrRect& srcRect,
840                               const GrMatrix* dstMatrix,
841                               const GrMatrix* srcMatrix) {
842    SK_TRACE_EVENT0("GrContext::drawRectToRect");
843
844    // srcRect refers to paint's first color stage
845    if (!paint.isColorStageEnabled(0)) {
846        drawRect(paint, dstRect, -1, dstMatrix);
847        return;
848    }
849
850    GrDrawTarget* target = this->prepareToDraw(&paint, DEFAULT_BUFFERING);
851
852#if GR_STATIC_RECT_VB
853    GrDrawState::AutoStageDisable atr(fDrawState);
854    GrDrawState* drawState = target->drawState();
855    GrDrawState::AutoViewMatrixRestore avmr(drawState);
856
857    GrMatrix m;
858
859    m.setAll(dstRect.width(), 0,                dstRect.fLeft,
860             0,               dstRect.height(), dstRect.fTop,
861             0,               0,                GrMatrix::I()[8]);
862    if (NULL != dstMatrix) {
863        m.postConcat(*dstMatrix);
864    }
865    drawState->preConcatViewMatrix(m);
866
867    // we explicitly setup the correct coords for the first stage. The others
868    // must know about the view matrix change.
869    for (int s = 1; s < GrPaint::kTotalStages; ++s) {
870        if (drawState->isStageEnabled(s)) {
871            drawState->sampler(s)->preConcatMatrix(m);
872        }
873    }
874
875    m.setAll(srcRect.width(), 0,                srcRect.fLeft,
876             0,               srcRect.height(), srcRect.fTop,
877             0,               0,                GrMatrix::I()[8]);
878    if (NULL != srcMatrix) {
879        m.postConcat(*srcMatrix);
880    }
881    drawState->sampler(GrPaint::kFirstColorStage)->preConcatMatrix(m);
882
883    const GrVertexBuffer* sqVB = fGpu->getUnitSquareVertexBuffer();
884    if (NULL == sqVB) {
885        GrPrintf("Failed to create static rect vb.\n");
886        return;
887    }
888    target->setVertexSourceToBuffer(0, sqVB);
889    target->drawNonIndexed(kTriangleFan_GrPrimitiveType, 0, 4);
890#else
891    GrDrawState::AutoStageDisable atr(fDrawState);
892
893    const GrRect* srcRects[GrDrawState::kNumStages] = {NULL};
894    const GrMatrix* srcMatrices[GrDrawState::kNumStages] = {NULL};
895    srcRects[0] = &srcRect;
896    srcMatrices[0] = srcMatrix;
897
898    target->drawRect(dstRect, dstMatrix, srcRects, srcMatrices);
899#endif
900}
901
902void GrContext::drawVertices(const GrPaint& paint,
903                             GrPrimitiveType primitiveType,
904                             int vertexCount,
905                             const GrPoint positions[],
906                             const GrPoint texCoords[],
907                             const GrColor colors[],
908                             const uint16_t indices[],
909                             int indexCount) {
910    SK_TRACE_EVENT0("GrContext::drawVertices");
911
912    GrDrawTarget::AutoReleaseGeometry geo;
913
914    GrDrawTarget* target = this->prepareToDraw(&paint, DEFAULT_BUFFERING);
915    GrDrawState::AutoStageDisable atr(fDrawState);
916
917    GrVertexLayout layout = 0;
918    if (NULL != texCoords) {
919        layout |= GrDrawTarget::StageTexCoordVertexLayoutBit(0, 0);
920    }
921    if (NULL != colors) {
922        layout |= GrDrawTarget::kColor_VertexLayoutBit;
923    }
924    int vertexSize = GrDrawTarget::VertexSize(layout);
925
926    if (sizeof(GrPoint) != vertexSize) {
927        if (!geo.set(target, layout, vertexCount, 0)) {
928            GrPrintf("Failed to get space for vertices!\n");
929            return;
930        }
931        int texOffsets[GrDrawState::kMaxTexCoords];
932        int colorOffset;
933        GrDrawTarget::VertexSizeAndOffsetsByIdx(layout,
934                                                texOffsets,
935                                                &colorOffset,
936                                                NULL,
937                                                NULL);
938        void* curVertex = geo.vertices();
939
940        for (int i = 0; i < vertexCount; ++i) {
941            *((GrPoint*)curVertex) = positions[i];
942
943            if (texOffsets[0] > 0) {
944                *(GrPoint*)((intptr_t)curVertex + texOffsets[0]) = texCoords[i];
945            }
946            if (colorOffset > 0) {
947                *(GrColor*)((intptr_t)curVertex + colorOffset) = colors[i];
948            }
949            curVertex = (void*)((intptr_t)curVertex + vertexSize);
950        }
951    } else {
952        target->setVertexSourceToArray(layout, positions, vertexCount);
953    }
954
955    // we don't currently apply offscreen AA to this path. Need improved
956    // management of GrDrawTarget's geometry to avoid copying points per-tile.
957
958    if (NULL != indices) {
959        target->setIndexSourceToArray(indices, indexCount);
960        target->drawIndexed(primitiveType, 0, 0, vertexCount, indexCount);
961    } else {
962        target->drawNonIndexed(primitiveType, 0, vertexCount);
963    }
964}
965
966///////////////////////////////////////////////////////////////////////////////
967namespace {
968
969struct CircleVertex {
970    GrPoint fPos;
971    GrPoint fCenter;
972    GrScalar fOuterRadius;
973    GrScalar fInnerRadius;
974};
975
976/* Returns true if will map a circle to another circle. This can be true
977 * if the matrix only includes square-scale, rotation, translation.
978 */
979inline bool isSimilarityTransformation(const SkMatrix& matrix,
980                                       SkScalar tol = SK_ScalarNearlyZero) {
981    if (matrix.isIdentity() || matrix.getType() == SkMatrix::kTranslate_Mask) {
982        return true;
983    }
984    if (matrix.hasPerspective()) {
985        return false;
986    }
987
988    SkScalar mx = matrix.get(SkMatrix::kMScaleX);
989    SkScalar sx = matrix.get(SkMatrix::kMSkewX);
990    SkScalar my = matrix.get(SkMatrix::kMScaleY);
991    SkScalar sy = matrix.get(SkMatrix::kMSkewY);
992
993    if (mx == 0 && sx == 0 && my == 0 && sy == 0) {
994        return false;
995    }
996
997    // it has scales or skews, but it could also be rotation, check it out.
998    SkVector vec[2];
999    vec[0].set(mx, sx);
1000    vec[1].set(sy, my);
1001
1002    return SkScalarNearlyZero(vec[0].dot(vec[1]), SkScalarSquare(tol)) &&
1003           SkScalarNearlyEqual(vec[0].lengthSqd(), vec[1].lengthSqd(),
1004                SkScalarSquare(tol));
1005}
1006
1007}
1008
1009// TODO: strokeWidth can't be larger than zero right now.
1010// It will be fixed when drawPath() can handle strokes.
1011void GrContext::drawOval(const GrPaint& paint,
1012                         const GrRect& rect,
1013                         SkScalar strokeWidth) {
1014    GrAssert(strokeWidth <= 0);
1015    if (!isSimilarityTransformation(this->getMatrix()) ||
1016        !paint.isAntiAlias() ||
1017        rect.height() != rect.width()) {
1018        SkPath path;
1019        path.addOval(rect);
1020        GrPathFill fill = (strokeWidth == 0) ?
1021                           kHairLine_GrPathFill : kWinding_GrPathFill;
1022        this->internalDrawPath(paint, path, fill, NULL);
1023        return;
1024    }
1025
1026    GrDrawTarget* target = this->prepareToDraw(&paint, DEFAULT_BUFFERING);
1027
1028    GrDrawState* drawState = target->drawState();
1029    GrDrawState::AutoStageDisable atr(fDrawState);
1030    const GrMatrix vm = drawState->getViewMatrix();
1031
1032    const GrRenderTarget* rt = drawState->getRenderTarget();
1033    if (NULL == rt) {
1034        return;
1035    }
1036
1037    GrDrawState::AutoDeviceCoordDraw adcd(drawState);
1038    if (!adcd.succeeded()) {
1039        return;
1040    }
1041
1042    GrVertexLayout layout = GrDrawTarget::kEdge_VertexLayoutBit;
1043    GrAssert(sizeof(CircleVertex) == GrDrawTarget::VertexSize(layout));
1044
1045    GrPoint center = GrPoint::Make(rect.centerX(), rect.centerY());
1046    GrScalar radius = SkScalarHalf(rect.width());
1047
1048    vm.mapPoints(&center, 1);
1049    radius = vm.mapRadius(radius);
1050
1051    GrScalar outerRadius = radius;
1052    GrScalar innerRadius = 0;
1053    SkScalar halfWidth = 0;
1054    if (strokeWidth == 0) {
1055        halfWidth = SkScalarHalf(SK_Scalar1);
1056
1057        outerRadius += halfWidth;
1058        innerRadius = SkMaxScalar(0, radius - halfWidth);
1059    }
1060
1061    GrDrawTarget::AutoReleaseGeometry geo(target, layout, 4, 0);
1062    if (!geo.succeeded()) {
1063        GrPrintf("Failed to get space for vertices!\n");
1064        return;
1065    }
1066
1067    CircleVertex* verts = reinterpret_cast<CircleVertex*>(geo.vertices());
1068
1069    // The fragment shader will extend the radius out half a pixel
1070    // to antialias. Expand the drawn rect here so all the pixels
1071    // will be captured.
1072    SkScalar L = center.fX - outerRadius - SkFloatToScalar(0.5f);
1073    SkScalar R = center.fX + outerRadius + SkFloatToScalar(0.5f);
1074    SkScalar T = center.fY - outerRadius - SkFloatToScalar(0.5f);
1075    SkScalar B = center.fY + outerRadius + SkFloatToScalar(0.5f);
1076
1077    verts[0].fPos = SkPoint::Make(L, T);
1078    verts[1].fPos = SkPoint::Make(R, T);
1079    verts[2].fPos = SkPoint::Make(L, B);
1080    verts[3].fPos = SkPoint::Make(R, B);
1081
1082    for (int i = 0; i < 4; ++i) {
1083        // this goes to fragment shader, it should be in y-points-up space.
1084        verts[i].fCenter = SkPoint::Make(center.fX, rt->height() - center.fY);
1085
1086        verts[i].fOuterRadius = outerRadius;
1087        verts[i].fInnerRadius = innerRadius;
1088    }
1089
1090    drawState->setVertexEdgeType(GrDrawState::kCircle_EdgeType);
1091    target->drawNonIndexed(kTriangleStrip_GrPrimitiveType, 0, 4);
1092}
1093
1094void GrContext::drawPath(const GrPaint& paint, const SkPath& path,
1095                         GrPathFill fill, const GrPoint* translate) {
1096
1097    if (path.isEmpty()) {
1098       if (GrIsFillInverted(fill)) {
1099           this->drawPaint(paint);
1100       }
1101       return;
1102    }
1103
1104    SkRect ovalRect;
1105    if (!GrIsFillInverted(fill) && path.isOval(&ovalRect)) {
1106        if (translate) {
1107            ovalRect.offset(*translate);
1108        }
1109        SkScalar width = (fill == kHairLine_GrPathFill) ? 0 : -SK_Scalar1;
1110        this->drawOval(paint, ovalRect, width);
1111        return;
1112    }
1113
1114    internalDrawPath(paint, path, fill, translate);
1115}
1116
1117void GrContext::internalDrawPath(const GrPaint& paint, const SkPath& path,
1118                                 GrPathFill fill, const GrPoint* translate) {
1119
1120    // Note that below we may sw-rasterize the path into a scratch texture.
1121    // Scratch textures can be recycled after they are returned to the texture
1122    // cache. This presents a potential hazard for buffered drawing. However,
1123    // the writePixels that uploads to the scratch will perform a flush so we're
1124    // OK.
1125    GrDrawTarget* target = this->prepareToDraw(&paint, DEFAULT_BUFFERING);
1126    GrDrawState::AutoStageDisable atr(fDrawState);
1127
1128    bool prAA = paint.isAntiAlias() && !this->getRenderTarget()->isMultisampled();
1129
1130    // An Assumption here is that path renderer would use some form of tweaking
1131    // the src color (either the input alpha or in the frag shader) to implement
1132    // aa. If we have some future driver-mojo path AA that can do the right
1133    // thing WRT to the blend then we'll need some query on the PR.
1134    if (disable_coverage_aa_for_blend(target)) {
1135#if GR_DEBUG
1136        //GrPrintf("Turning off AA to correctly apply blend.\n");
1137#endif
1138        prAA = false;
1139    }
1140
1141    GrPathRenderer* pr = this->getPathRenderer(path, fill, target, prAA, true);
1142    if (NULL == pr) {
1143#if GR_DEBUG
1144        GrPrintf("Unable to find path renderer compatible with path.\n");
1145#endif
1146        return;
1147    }
1148
1149    pr->drawPath(path, fill, translate, target, prAA);
1150}
1151
1152////////////////////////////////////////////////////////////////////////////////
1153
1154void GrContext::flush(int flagsBitfield) {
1155    if (kDiscard_FlushBit & flagsBitfield) {
1156        fDrawBuffer->reset();
1157    } else {
1158        this->flushDrawBuffer();
1159    }
1160    if (kForceCurrentRenderTarget_FlushBit & flagsBitfield) {
1161        fGpu->forceRenderTargetFlush();
1162    }
1163}
1164
1165void GrContext::flushDrawBuffer() {
1166    if (fDrawBuffer) {
1167        // With addition of the AA clip path, flushing the draw buffer can
1168        // result in the generation of an AA clip mask. During this
1169        // process the SW path renderer may be invoked which recusively
1170        // calls this method (via internalWriteTexturePixels) creating
1171        // infinite recursion
1172        GrInOrderDrawBuffer* temp = fDrawBuffer;
1173        fDrawBuffer = NULL;
1174
1175        temp->flushTo(fGpu);
1176
1177        fDrawBuffer = temp;
1178    }
1179}
1180
1181void GrContext::writeTexturePixels(GrTexture* texture,
1182                                   int left, int top, int width, int height,
1183                                   GrPixelConfig config, const void* buffer, size_t rowBytes,
1184                                   uint32_t flags) {
1185    SK_TRACE_EVENT0("GrContext::writeTexturePixels");
1186    ASSERT_OWNED_RESOURCE(texture);
1187
1188    // TODO: use scratch texture to perform conversion
1189    if (kUnpremul_PixelOpsFlag & flags) {
1190        return;
1191    }
1192    if (!(kDontFlush_PixelOpsFlag & flags)) {
1193        this->flush();
1194    }
1195
1196    fGpu->writeTexturePixels(texture, left, top, width, height,
1197                             config, buffer, rowBytes);
1198}
1199
1200bool GrContext::readTexturePixels(GrTexture* texture,
1201                                  int left, int top, int width, int height,
1202                                  GrPixelConfig config, void* buffer, size_t rowBytes,
1203                                  uint32_t flags) {
1204    SK_TRACE_EVENT0("GrContext::readTexturePixels");
1205    ASSERT_OWNED_RESOURCE(texture);
1206
1207    // TODO: code read pixels for textures that aren't also rendertargets
1208    GrRenderTarget* target = texture->asRenderTarget();
1209    if (NULL != target) {
1210        return this->readRenderTargetPixels(target,
1211                                            left, top, width, height,
1212                                            config, buffer, rowBytes,
1213                                            flags);
1214    } else {
1215        return false;
1216    }
1217}
1218
1219#include "SkConfig8888.h"
1220
1221namespace {
1222/**
1223 * Converts a GrPixelConfig to a SkCanvas::Config8888. Only byte-per-channel
1224 * formats are representable as Config8888 and so the function returns false
1225 * if the GrPixelConfig has no equivalent Config8888.
1226 */
1227bool grconfig_to_config8888(GrPixelConfig config,
1228                            bool unpremul,
1229                            SkCanvas::Config8888* config8888) {
1230    switch (config) {
1231        case kRGBA_8888_GrPixelConfig:
1232            if (unpremul) {
1233                *config8888 = SkCanvas::kRGBA_Unpremul_Config8888;
1234            } else {
1235                *config8888 = SkCanvas::kRGBA_Premul_Config8888;
1236            }
1237            return true;
1238        case kBGRA_8888_GrPixelConfig:
1239            if (unpremul) {
1240                *config8888 = SkCanvas::kBGRA_Unpremul_Config8888;
1241            } else {
1242                *config8888 = SkCanvas::kBGRA_Premul_Config8888;
1243            }
1244            return true;
1245        default:
1246            return false;
1247    }
1248}
1249
1250// It returns a configuration with where the byte position of the R & B components are swapped in
1251// relation to the input config. This should only be called with the result of
1252// grconfig_to_config8888 as it will fail for other configs.
1253SkCanvas::Config8888 swap_config8888_red_and_blue(SkCanvas::Config8888 config8888) {
1254    switch (config8888) {
1255        case SkCanvas::kBGRA_Premul_Config8888:
1256            return SkCanvas::kRGBA_Premul_Config8888;
1257        case SkCanvas::kBGRA_Unpremul_Config8888:
1258            return SkCanvas::kRGBA_Unpremul_Config8888;
1259        case SkCanvas::kRGBA_Premul_Config8888:
1260            return SkCanvas::kBGRA_Premul_Config8888;
1261        case SkCanvas::kRGBA_Unpremul_Config8888:
1262            return SkCanvas::kBGRA_Unpremul_Config8888;
1263        default:
1264            GrCrash("Unexpected input");
1265            return SkCanvas::kBGRA_Unpremul_Config8888;;
1266    }
1267}
1268}
1269
1270bool GrContext::readRenderTargetPixels(GrRenderTarget* target,
1271                                       int left, int top, int width, int height,
1272                                       GrPixelConfig config, void* buffer, size_t rowBytes,
1273                                       uint32_t flags) {
1274    SK_TRACE_EVENT0("GrContext::readRenderTargetPixels");
1275    ASSERT_OWNED_RESOURCE(target);
1276
1277    if (NULL == target) {
1278        target = fDrawState->getRenderTarget();
1279        if (NULL == target) {
1280            return false;
1281        }
1282    }
1283
1284    if (!(kDontFlush_PixelOpsFlag & flags)) {
1285        this->flush();
1286    }
1287
1288    // Determine which conversions have to be applied: flipY, swapRAnd, and/or unpremul.
1289
1290    // If fGpu->readPixels would incur a y-flip cost then we will read the pixels upside down. We'll
1291    // either do the flipY by drawing into a scratch with a matrix or on the cpu after the read.
1292    bool flipY = fGpu->readPixelsWillPayForYFlip(target, left, top,
1293                                                 width, height, config,
1294                                                 rowBytes);
1295    bool swapRAndB = fGpu->preferredReadPixelsConfig(config) == GrPixelConfigSwapRAndB(config);
1296
1297    bool unpremul = SkToBool(kUnpremul_PixelOpsFlag & flags);
1298
1299    // flipY will get set to false when it is handled below using a scratch. However, in that case
1300    // we still want to do the read upside down.
1301    bool readUpsideDown = flipY;
1302
1303    if (unpremul && kRGBA_8888_GrPixelConfig != config && kBGRA_8888_GrPixelConfig != config) {
1304        // The unpremul flag is only allowed for these two configs.
1305        return false;
1306    }
1307
1308    GrPixelConfig readConfig;
1309    if (swapRAndB) {
1310        readConfig = GrPixelConfigSwapRAndB(config);
1311        GrAssert(kUnknown_GrPixelConfig != config);
1312    } else {
1313        readConfig = config;
1314    }
1315
1316    // If the src is a texture and we would have to do conversions after read pixels, we instead
1317    // do the conversions by drawing the src to a scratch texture. If we handle any of the
1318    // conversions in the draw we set the corresponding bool to false so that we don't reapply it
1319    // on the read back pixels.
1320    GrTexture* src = target->asTexture();
1321    GrAutoScratchTexture ast;
1322    if (NULL != src && (swapRAndB || unpremul || flipY)) {
1323        // Make the scratch a render target because we don't have a robust readTexturePixels as of
1324        // yet. It calls this function.
1325        GrTextureDesc desc;
1326        desc.fFlags = kRenderTarget_GrTextureFlagBit;
1327        desc.fWidth = width;
1328        desc.fHeight = height;
1329        desc.fConfig = readConfig;
1330
1331        // When a full readback is faster than a partial we could always make the scratch exactly
1332        // match the passed rect. However, if we see many different size rectangles we will trash
1333        // our texture cache and pay the cost of creating and destroying many textures. So, we only
1334        // request an exact match when the caller is reading an entire RT.
1335        ScratchTexMatch match = kApprox_ScratchTexMatch;
1336        if (0 == left &&
1337            0 == top &&
1338            target->width() == width &&
1339            target->height() == height &&
1340            fGpu->fullReadPixelsIsFasterThanPartial()) {
1341            match = kExact_ScratchTexMatch;
1342        }
1343        ast.set(this, desc, match);
1344        GrTexture* texture = ast.texture();
1345        if (texture) {
1346            SkAutoTUnref<GrCustomStage> stage;
1347            if (unpremul) {
1348                stage.reset(this->createPMToUPMEffect(src, swapRAndB));
1349            }
1350            // If we failed to create a PM->UPM effect and have no other conversions to perform then
1351            // there is no longer any point to using the scratch.
1352            if (NULL != stage || flipY || swapRAndB) {
1353                if (NULL == stage) {
1354                    stage.reset(GrConfigConversionEffect::Create(src, swapRAndB));
1355                    GrAssert(NULL != stage);
1356                } else {
1357                    unpremul = false; // we will handle the UPM conversion in the draw
1358                }
1359                swapRAndB = false; // we will handle the swap in the draw.
1360
1361                GrDrawTarget::AutoStateRestore asr(fGpu, GrDrawTarget::kReset_ASRInit);
1362                GrDrawState* drawState = fGpu->drawState();
1363                drawState->setRenderTarget(texture->asRenderTarget());
1364                GrMatrix matrix;
1365                if (flipY) {
1366                    matrix.setTranslate(SK_Scalar1 * left,
1367                                        SK_Scalar1 * (top + height));
1368                    matrix.set(GrMatrix::kMScaleY, -GR_Scalar1);
1369                    flipY = false; // the y flip will be handled in the draw
1370                } else {
1371                    matrix.setTranslate(SK_Scalar1 *left, SK_Scalar1 *top);
1372                }
1373                matrix.postIDiv(src->width(), src->height());
1374                drawState->sampler(0)->reset(matrix);
1375                drawState->sampler(0)->setCustomStage(stage);
1376                GrRect rect = GrRect::MakeWH(GrIntToScalar(width), GrIntToScalar(height));
1377                fGpu->drawSimpleRect(rect, NULL);
1378                // we want to read back from the scratch's origin
1379                left = 0;
1380                top = 0;
1381                target = texture->asRenderTarget();
1382            }
1383        }
1384    }
1385    if (!fGpu->readPixels(target,
1386                          left, top, width, height,
1387                          readConfig, buffer, rowBytes, readUpsideDown)) {
1388        return false;
1389    }
1390    // Perform any conversions we weren't able to perfom using a scratch texture.
1391    if (unpremul || swapRAndB || flipY) {
1392        // These are initialized to suppress a warning
1393        SkCanvas::Config8888 srcC8888 = SkCanvas::kNative_Premul_Config8888;
1394        SkCanvas::Config8888 dstC8888 = SkCanvas::kNative_Premul_Config8888;
1395
1396        bool c8888IsValid = grconfig_to_config8888(config, false, &srcC8888);
1397        grconfig_to_config8888(config, unpremul, &dstC8888);
1398
1399        if (swapRAndB) {
1400            GrAssert(c8888IsValid); // we should only do r/b swap on 8888 configs
1401            srcC8888 = swap_config8888_red_and_blue(srcC8888);
1402        }
1403        if (flipY) {
1404            size_t tightRB = width * GrBytesPerPixel(config);
1405            if (0 == rowBytes) {
1406                rowBytes = tightRB;
1407            }
1408            SkAutoSTMalloc<256, uint8_t> tempRow(tightRB);
1409            intptr_t top = reinterpret_cast<intptr_t>(buffer);
1410            intptr_t bot = top + (height - 1) * rowBytes;
1411            while (top < bot) {
1412                uint32_t* t = reinterpret_cast<uint32_t*>(top);
1413                uint32_t* b = reinterpret_cast<uint32_t*>(bot);
1414                uint32_t* temp = reinterpret_cast<uint32_t*>(tempRow.get());
1415                memcpy(temp, t, tightRB);
1416                if (c8888IsValid) {
1417                    SkConvertConfig8888Pixels(t, tightRB, dstC8888,
1418                                              b, tightRB, srcC8888,
1419                                              width, 1);
1420                    SkConvertConfig8888Pixels(b, tightRB, dstC8888,
1421                                              temp, tightRB, srcC8888,
1422                                              width, 1);
1423                } else {
1424                    memcpy(t, b, tightRB);
1425                    memcpy(b, temp, tightRB);
1426                }
1427                top += rowBytes;
1428                bot -= rowBytes;
1429            }
1430            // The above loop does nothing on the middle row when height is odd.
1431            if (top == bot && c8888IsValid && dstC8888 != srcC8888) {
1432                uint32_t* mid = reinterpret_cast<uint32_t*>(top);
1433                SkConvertConfig8888Pixels(mid, tightRB, dstC8888, mid, tightRB, srcC8888, width, 1);
1434            }
1435        } else {
1436            // if we aren't flipping Y then we have no reason to be here other than doing
1437            // conversions for 8888 (r/b swap or upm).
1438            GrAssert(c8888IsValid);
1439            uint32_t* b32 = reinterpret_cast<uint32_t*>(buffer);
1440            SkConvertConfig8888Pixels(b32, rowBytes, dstC8888,
1441                                      b32, rowBytes, srcC8888,
1442                                      width, height);
1443        }
1444    }
1445    return true;
1446}
1447
1448void GrContext::resolveRenderTarget(GrRenderTarget* target) {
1449    GrAssert(target);
1450    ASSERT_OWNED_RESOURCE(target);
1451    // In the future we may track whether there are any pending draws to this
1452    // target. We don't today so we always perform a flush. We don't promise
1453    // this to our clients, though.
1454    this->flush();
1455    fGpu->resolveRenderTarget(target);
1456}
1457
1458void GrContext::copyTexture(GrTexture* src, GrRenderTarget* dst) {
1459    if (NULL == src || NULL == dst) {
1460        return;
1461    }
1462    ASSERT_OWNED_RESOURCE(src);
1463
1464    // Writes pending to the source texture are not tracked, so a flush
1465    // is required to ensure that the copy captures the most recent contents
1466    // of the source texture. See similar behaviour in
1467    // GrContext::resolveRenderTarget.
1468    this->flush();
1469
1470    GrDrawTarget::AutoStateRestore asr(fGpu, GrDrawTarget::kReset_ASRInit);
1471    GrDrawState* drawState = fGpu->drawState();
1472    drawState->setRenderTarget(dst);
1473    GrMatrix sampleM;
1474    sampleM.setIDiv(src->width(), src->height());
1475    drawState->sampler(0)->reset(sampleM);
1476    drawState->createTextureEffect(0, src);
1477    SkRect rect = SkRect::MakeXYWH(0, 0,
1478                                   SK_Scalar1 * src->width(),
1479                                   SK_Scalar1 * src->height());
1480    fGpu->drawSimpleRect(rect, NULL);
1481}
1482
1483void GrContext::writeRenderTargetPixels(GrRenderTarget* target,
1484                                        int left, int top, int width, int height,
1485                                        GrPixelConfig config,
1486                                        const void* buffer,
1487                                        size_t rowBytes,
1488                                        uint32_t flags) {
1489    SK_TRACE_EVENT0("GrContext::writeRenderTargetPixels");
1490    ASSERT_OWNED_RESOURCE(target);
1491
1492    if (NULL == target) {
1493        target = fDrawState->getRenderTarget();
1494        if (NULL == target) {
1495            return;
1496        }
1497    }
1498
1499    // TODO: when underlying api has a direct way to do this we should use it (e.g. glDrawPixels on
1500    // desktop GL).
1501
1502    // We will always call some form of writeTexturePixels and we will pass our flags on to it.
1503    // Thus, we don't perform a flush here since that call will do it (if the kNoFlush flag isn't
1504    // set.)
1505
1506    // If the RT is also a texture and we don't have to premultiply then take the texture path.
1507    // We expect to be at least as fast or faster since it doesn't use an intermediate texture as
1508    // we do below.
1509
1510#if !GR_MAC_BUILD
1511    // At least some drivers on the Mac get confused when glTexImage2D is called on a texture
1512    // attached to an FBO. The FBO still sees the old image. TODO: determine what OS versions and/or
1513    // HW is affected.
1514    if (NULL != target->asTexture() && !(kUnpremul_PixelOpsFlag & flags)) {
1515        this->writeTexturePixels(target->asTexture(),
1516                                 left, top, width, height,
1517                                 config, buffer, rowBytes, flags);
1518        return;
1519    }
1520#endif
1521    SkAutoTUnref<GrCustomStage> stage;
1522    bool swapRAndB = (fGpu->preferredReadPixelsConfig(config) == GrPixelConfigSwapRAndB(config));
1523
1524    GrPixelConfig textureConfig;
1525    if (swapRAndB) {
1526        textureConfig = GrPixelConfigSwapRAndB(config);
1527    } else {
1528        textureConfig = config;
1529    }
1530
1531    GrTextureDesc desc;
1532    desc.fWidth = width;
1533    desc.fHeight = height;
1534    desc.fConfig = textureConfig;
1535    GrAutoScratchTexture ast(this, desc);
1536    GrTexture* texture = ast.texture();
1537    if (NULL == texture) {
1538        return;
1539    }
1540    // allocate a tmp buffer and sw convert the pixels to premul
1541    SkAutoSTMalloc<128 * 128, uint32_t> tmpPixels(0);
1542
1543    if (kUnpremul_PixelOpsFlag & flags) {
1544        if (kRGBA_8888_GrPixelConfig != config && kBGRA_8888_GrPixelConfig != config) {
1545            return;
1546        }
1547        stage.reset(this->createUPMToPMEffect(texture, swapRAndB));
1548        if (NULL == stage) {
1549            SkCanvas::Config8888 srcConfig8888, dstConfig8888;
1550            GR_DEBUGCODE(bool success = )
1551            grconfig_to_config8888(config, true, &srcConfig8888);
1552            GrAssert(success);
1553            GR_DEBUGCODE(success = )
1554            grconfig_to_config8888(config, false, &dstConfig8888);
1555            GrAssert(success);
1556            const uint32_t* src = reinterpret_cast<const uint32_t*>(buffer);
1557            tmpPixels.reset(width * height);
1558            SkConvertConfig8888Pixels(tmpPixels.get(), 4 * width, dstConfig8888,
1559                                      src, rowBytes, srcConfig8888,
1560                                      width, height);
1561            buffer = tmpPixels.get();
1562            rowBytes = 4 * width;
1563        }
1564    }
1565    if (NULL == stage) {
1566        stage.reset(GrConfigConversionEffect::Create(texture, swapRAndB));
1567        GrAssert(NULL != stage);
1568    }
1569
1570    this->writeTexturePixels(texture,
1571                             0, 0, width, height,
1572                             textureConfig, buffer, rowBytes,
1573                             flags & ~kUnpremul_PixelOpsFlag);
1574
1575    GrDrawTarget::AutoStateRestore  asr(fGpu, GrDrawTarget::kReset_ASRInit);
1576    GrDrawState* drawState = fGpu->drawState();
1577
1578    GrMatrix matrix;
1579    matrix.setTranslate(GrIntToScalar(left), GrIntToScalar(top));
1580    drawState->setViewMatrix(matrix);
1581    drawState->setRenderTarget(target);
1582
1583    matrix.setIDiv(texture->width(), texture->height());
1584    drawState->sampler(0)->reset(matrix);
1585    drawState->sampler(0)->setCustomStage(stage);
1586
1587    fGpu->drawSimpleRect(GrRect::MakeWH(SkIntToScalar(width), SkIntToScalar(height)), NULL);
1588}
1589////////////////////////////////////////////////////////////////////////////////
1590
1591GrDrawTarget* GrContext::prepareToDraw(const GrPaint* paint, BufferedDraw buffered) {
1592    if (kNo_BufferedDraw == buffered && kYes_BufferedDraw == fLastDrawWasBuffered) {
1593        this->flushDrawBuffer();
1594        fLastDrawWasBuffered = kNo_BufferedDraw;
1595    }
1596    if (NULL != paint) {
1597        GrAssert(fDrawState->stagesDisabled());
1598        fDrawState->setFromPaint(*paint);
1599#if GR_DEBUG_PARTIAL_COVERAGE_CHECK
1600        if ((paint->hasMask() || 0xff != paint->fCoverage) &&
1601            !fGpu->canApplyCoverage()) {
1602            GrPrintf("Partial pixel coverage will be incorrectly blended.\n");
1603        }
1604#endif
1605    }
1606    if (kYes_BufferedDraw == buffered) {
1607        fDrawBuffer->setClip(fGpu->getClip());
1608        fLastDrawWasBuffered = kYes_BufferedDraw;
1609        return fDrawBuffer;
1610    } else {
1611        GrAssert(kNo_BufferedDraw == buffered);
1612        return fGpu;
1613    }
1614}
1615
1616/*
1617 * This method finds a path renderer that can draw the specified path on
1618 * the provided target.
1619 * Due to its expense, the software path renderer has split out so it can
1620 * can be individually allowed/disallowed via the "allowSW" boolean.
1621 */
1622GrPathRenderer* GrContext::getPathRenderer(const SkPath& path,
1623                                           GrPathFill fill,
1624                                           const GrDrawTarget* target,
1625                                           bool antiAlias,
1626                                           bool allowSW) {
1627    if (NULL == fPathRendererChain) {
1628        fPathRendererChain =
1629            SkNEW_ARGS(GrPathRendererChain,
1630                       (this, GrPathRendererChain::kNone_UsageFlag));
1631    }
1632
1633    GrPathRenderer* pr = fPathRendererChain->getPathRenderer(path, fill,
1634                                                             target,
1635                                                             antiAlias);
1636
1637    if (NULL == pr && allowSW) {
1638        if (NULL == fSoftwarePathRenderer) {
1639            fSoftwarePathRenderer = SkNEW_ARGS(GrSoftwarePathRenderer, (this));
1640        }
1641
1642        pr = fSoftwarePathRenderer;
1643    }
1644
1645    return pr;
1646}
1647
1648////////////////////////////////////////////////////////////////////////////////
1649
1650void GrContext::setRenderTarget(GrRenderTarget* target) {
1651    ASSERT_OWNED_RESOURCE(target);
1652    fDrawState->setRenderTarget(target);
1653}
1654
1655GrRenderTarget* GrContext::getRenderTarget() {
1656    return fDrawState->getRenderTarget();
1657}
1658
1659const GrRenderTarget* GrContext::getRenderTarget() const {
1660    return fDrawState->getRenderTarget();
1661}
1662
1663bool GrContext::isConfigRenderable(GrPixelConfig config) const {
1664    return fGpu->isConfigRenderable(config);
1665}
1666
1667const GrMatrix& GrContext::getMatrix() const {
1668    return fDrawState->getViewMatrix();
1669}
1670
1671void GrContext::setMatrix(const GrMatrix& m) {
1672    fDrawState->setViewMatrix(m);
1673}
1674
1675void GrContext::concatMatrix(const GrMatrix& m) const {
1676    fDrawState->preConcatViewMatrix(m);
1677}
1678
1679static inline intptr_t setOrClear(intptr_t bits, int shift, intptr_t pred) {
1680    intptr_t mask = 1 << shift;
1681    if (pred) {
1682        bits |= mask;
1683    } else {
1684        bits &= ~mask;
1685    }
1686    return bits;
1687}
1688
1689GrContext::GrContext(GrGpu* gpu) {
1690    ++THREAD_INSTANCE_COUNT;
1691
1692    fGpu = gpu;
1693    fGpu->ref();
1694    fGpu->setContext(this);
1695
1696    fDrawState = SkNEW(GrDrawState);
1697    fGpu->setDrawState(fDrawState);
1698
1699    fPathRendererChain = NULL;
1700    fSoftwarePathRenderer = NULL;
1701
1702    fTextureCache = SkNEW_ARGS(GrResourceCache,
1703                               (MAX_TEXTURE_CACHE_COUNT,
1704                                MAX_TEXTURE_CACHE_BYTES));
1705    fFontCache = SkNEW_ARGS(GrFontCache, (fGpu));
1706
1707    fLastDrawWasBuffered = kNo_BufferedDraw;
1708
1709    fDrawBuffer = NULL;
1710    fDrawBufferVBAllocPool = NULL;
1711    fDrawBufferIBAllocPool = NULL;
1712
1713    fAARectRenderer = SkNEW(GrAARectRenderer);
1714
1715    fDidTestPMConversions = false;
1716
1717    this->setupDrawBuffer();
1718}
1719
1720void GrContext::setupDrawBuffer() {
1721
1722    GrAssert(NULL == fDrawBuffer);
1723    GrAssert(NULL == fDrawBufferVBAllocPool);
1724    GrAssert(NULL == fDrawBufferIBAllocPool);
1725
1726    fDrawBufferVBAllocPool =
1727        SkNEW_ARGS(GrVertexBufferAllocPool, (fGpu, false,
1728                                    DRAW_BUFFER_VBPOOL_BUFFER_SIZE,
1729                                    DRAW_BUFFER_VBPOOL_PREALLOC_BUFFERS));
1730    fDrawBufferIBAllocPool =
1731        SkNEW_ARGS(GrIndexBufferAllocPool, (fGpu, false,
1732                                   DRAW_BUFFER_IBPOOL_BUFFER_SIZE,
1733                                   DRAW_BUFFER_IBPOOL_PREALLOC_BUFFERS));
1734
1735    fDrawBuffer = SkNEW_ARGS(GrInOrderDrawBuffer, (fGpu,
1736                                          fDrawBufferVBAllocPool,
1737                                          fDrawBufferIBAllocPool));
1738
1739    fDrawBuffer->setQuadIndexBuffer(this->getQuadIndexBuffer());
1740    if (fDrawBuffer) {
1741        fDrawBuffer->setAutoFlushTarget(fGpu);
1742        fDrawBuffer->setDrawState(fDrawState);
1743    }
1744}
1745
1746GrDrawTarget* GrContext::getTextTarget(const GrPaint& paint) {
1747    return prepareToDraw(&paint, DEFAULT_BUFFERING);
1748}
1749
1750const GrIndexBuffer* GrContext::getQuadIndexBuffer() const {
1751    return fGpu->getQuadIndexBuffer();
1752}
1753
1754namespace {
1755void test_pm_conversions(GrContext* ctx, int* pmToUPMValue, int* upmToPMValue) {
1756    GrConfigConversionEffect::PMConversion pmToUPM;
1757    GrConfigConversionEffect::PMConversion upmToPM;
1758    GrConfigConversionEffect::TestForPreservingPMConversions(ctx, &pmToUPM, &upmToPM);
1759    *pmToUPMValue = pmToUPM;
1760    *upmToPMValue = upmToPM;
1761}
1762}
1763
1764GrCustomStage* GrContext::createPMToUPMEffect(GrTexture* texture, bool swapRAndB) {
1765    if (!fDidTestPMConversions) {
1766        test_pm_conversions(this, &fPMToUPMConversion, &fUPMToPMConversion);
1767        fDidTestPMConversions = true;
1768    }
1769    GrConfigConversionEffect::PMConversion pmToUPM =
1770        static_cast<GrConfigConversionEffect::PMConversion>(fPMToUPMConversion);
1771    if (GrConfigConversionEffect::kNone_PMConversion != pmToUPM) {
1772        return GrConfigConversionEffect::Create(texture, swapRAndB, pmToUPM);
1773    } else {
1774        return NULL;
1775    }
1776}
1777
1778GrCustomStage* GrContext::createUPMToPMEffect(GrTexture* texture, bool swapRAndB) {
1779    if (!fDidTestPMConversions) {
1780        test_pm_conversions(this, &fPMToUPMConversion, &fUPMToPMConversion);
1781        fDidTestPMConversions = true;
1782    }
1783    GrConfigConversionEffect::PMConversion upmToPM =
1784        static_cast<GrConfigConversionEffect::PMConversion>(fUPMToPMConversion);
1785    if (GrConfigConversionEffect::kNone_PMConversion != upmToPM) {
1786        return GrConfigConversionEffect::Create(texture, swapRAndB, upmToPM);
1787    } else {
1788        return NULL;
1789    }
1790}
1791
1792GrTexture* GrContext::gaussianBlur(GrTexture* srcTexture,
1793                                   bool canClobberSrc,
1794                                   const SkRect& rect,
1795                                   float sigmaX, float sigmaY) {
1796    ASSERT_OWNED_RESOURCE(srcTexture);
1797
1798    AutoRenderTarget art(this);
1799
1800    AutoMatrix avm(this, GrMatrix::I());
1801    SkIRect clearRect;
1802    int scaleFactorX, radiusX;
1803    int scaleFactorY, radiusY;
1804    sigmaX = adjust_sigma(sigmaX, &scaleFactorX, &radiusX);
1805    sigmaY = adjust_sigma(sigmaY, &scaleFactorY, &radiusY);
1806
1807    SkRect srcRect(rect);
1808    scale_rect(&srcRect, 1.0f / scaleFactorX, 1.0f / scaleFactorY);
1809    srcRect.roundOut();
1810    scale_rect(&srcRect, static_cast<float>(scaleFactorX),
1811                         static_cast<float>(scaleFactorY));
1812
1813    AutoClip acs(this, srcRect);
1814
1815    GrAssert(kBGRA_8888_GrPixelConfig == srcTexture->config() ||
1816             kRGBA_8888_GrPixelConfig == srcTexture->config() ||
1817             kAlpha_8_GrPixelConfig == srcTexture->config());
1818
1819    GrTextureDesc desc;
1820    desc.fFlags = kRenderTarget_GrTextureFlagBit | kNoStencil_GrTextureFlagBit;
1821    desc.fWidth = SkScalarFloorToInt(srcRect.width());
1822    desc.fHeight = SkScalarFloorToInt(srcRect.height());
1823    desc.fConfig = srcTexture->config();
1824
1825    GrAutoScratchTexture temp1, temp2;
1826    GrTexture* dstTexture = temp1.set(this, desc);
1827    GrTexture* tempTexture = canClobberSrc ? srcTexture : temp2.set(this, desc);
1828
1829    GrPaint paint;
1830    paint.reset();
1831
1832    for (int i = 1; i < scaleFactorX || i < scaleFactorY; i *= 2) {
1833        paint.colorSampler(0)->matrix()->setIDiv(srcTexture->width(),
1834                                                   srcTexture->height());
1835        this->setRenderTarget(dstTexture->asRenderTarget());
1836        SkRect dstRect(srcRect);
1837        scale_rect(&dstRect, i < scaleFactorX ? 0.5f : 1.0f,
1838                            i < scaleFactorY ? 0.5f : 1.0f);
1839        paint.colorSampler(0)->setCustomStage(SkNEW_ARGS(GrSingleTextureEffect,
1840                                                           (srcTexture, true)))->unref();
1841        this->drawRectToRect(paint, dstRect, srcRect);
1842        srcRect = dstRect;
1843        srcTexture = dstTexture;
1844        SkTSwap(dstTexture, tempTexture);
1845    }
1846
1847    SkIRect srcIRect;
1848    srcRect.roundOut(&srcIRect);
1849
1850    if (sigmaX > 0.0f) {
1851        if (scaleFactorX > 1) {
1852            // Clear out a radius to the right of the srcRect to prevent the
1853            // X convolution from reading garbage.
1854            clearRect = SkIRect::MakeXYWH(srcIRect.fRight, srcIRect.fTop,
1855                                          radiusX, srcIRect.height());
1856            this->clear(&clearRect, 0x0);
1857        }
1858
1859        this->setRenderTarget(dstTexture->asRenderTarget());
1860        GrDrawTarget* target = this->prepareToDraw(NULL, DEFAULT_BUFFERING);
1861        convolve_gaussian(target, srcTexture, srcRect, sigmaX, radiusX,
1862                          Gr1DKernelEffect::kX_Direction);
1863        srcTexture = dstTexture;
1864        SkTSwap(dstTexture, tempTexture);
1865    }
1866
1867    if (sigmaY > 0.0f) {
1868        if (scaleFactorY > 1 || sigmaX > 0.0f) {
1869            // Clear out a radius below the srcRect to prevent the Y
1870            // convolution from reading garbage.
1871            clearRect = SkIRect::MakeXYWH(srcIRect.fLeft, srcIRect.fBottom,
1872                                          srcIRect.width(), radiusY);
1873            this->clear(&clearRect, 0x0);
1874        }
1875
1876        this->setRenderTarget(dstTexture->asRenderTarget());
1877        GrDrawTarget* target = this->prepareToDraw(NULL, DEFAULT_BUFFERING);
1878        convolve_gaussian(target, srcTexture, srcRect, sigmaY, radiusY,
1879                          Gr1DKernelEffect::kY_Direction);
1880        srcTexture = dstTexture;
1881        SkTSwap(dstTexture, tempTexture);
1882    }
1883
1884    if (scaleFactorX > 1 || scaleFactorY > 1) {
1885        // Clear one pixel to the right and below, to accommodate bilinear
1886        // upsampling.
1887        clearRect = SkIRect::MakeXYWH(srcIRect.fLeft, srcIRect.fBottom,
1888                                      srcIRect.width() + 1, 1);
1889        this->clear(&clearRect, 0x0);
1890        clearRect = SkIRect::MakeXYWH(srcIRect.fRight, srcIRect.fTop,
1891                                      1, srcIRect.height());
1892        this->clear(&clearRect, 0x0);
1893        // FIXME:  This should be mitchell, not bilinear.
1894        paint.colorSampler(0)->matrix()->setIDiv(srcTexture->width(),
1895                                                   srcTexture->height());
1896        this->setRenderTarget(dstTexture->asRenderTarget());
1897        paint.colorSampler(0)->setCustomStage(SkNEW_ARGS(GrSingleTextureEffect,
1898                                                           (srcTexture, true)))->unref();
1899        SkRect dstRect(srcRect);
1900        scale_rect(&dstRect, (float) scaleFactorX, (float) scaleFactorY);
1901        this->drawRectToRect(paint, dstRect, srcRect);
1902        srcRect = dstRect;
1903        srcTexture = dstTexture;
1904        SkTSwap(dstTexture, tempTexture);
1905    }
1906    if (srcTexture == temp1.texture()) {
1907        return temp1.detach();
1908    } else if (srcTexture == temp2.texture()) {
1909        return temp2.detach();
1910    } else {
1911        srcTexture->ref();
1912        return srcTexture;
1913    }
1914}
1915
1916///////////////////////////////////////////////////////////////////////////////
1917#if GR_CACHE_STATS
1918void GrContext::printCacheStats() const {
1919    fTextureCache->printStats();
1920}
1921#endif
1922