OpenGLRenderer.cpp revision 34416eaa1c07b3d7a139e780cea8f8d73219650e 
1/*
2 * Copyright (C) 2010 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#define LOG_TAG "OpenGLRenderer"
18
19#include <stdlib.h>
20#include <stdint.h>
21#include <sys/types.h>
22
23#include <SkCanvas.h>
24#include <SkPathMeasure.h>
25#include <SkTypeface.h>
26
27#include <utils/Log.h>
28#include <utils/StopWatch.h>
29
30#include <private/hwui/DrawGlInfo.h>
31
32#include <ui/Rect.h>
33
34#include "OpenGLRenderer.h"
35#include "DeferredDisplayList.h"
36#include "DisplayListRenderer.h"
37#include "PathTessellator.h"
38#include "Properties.h"
39#include "Vector.h"
40
41namespace android {
42namespace uirenderer {
43
44///////////////////////////////////////////////////////////////////////////////
45// Defines
46///////////////////////////////////////////////////////////////////////////////
47
48#define RAD_TO_DEG (180.0f / 3.14159265f)
49#define MIN_ANGLE 0.001f
50
51#define ALPHA_THRESHOLD 0
52
53#define FILTER(paint) (!paint || paint->isFilterBitmap() ? GL_LINEAR : GL_NEAREST)
54
55///////////////////////////////////////////////////////////////////////////////
56// Globals
57///////////////////////////////////////////////////////////////////////////////
58
59/**
60 * Structure mapping Skia xfermodes to OpenGL blending factors.
61 */
62struct Blender {
63    SkXfermode::Mode mode;
64    GLenum src;
65    GLenum dst;
66}; // struct Blender
67
68// In this array, the index of each Blender equals the value of the first
69// entry. For instance, gBlends[1] == gBlends[SkXfermode::kSrc_Mode]
70static const Blender gBlends[] = {
71    { SkXfermode::kClear_Mode,    GL_ZERO,                GL_ONE_MINUS_SRC_ALPHA },
72    { SkXfermode::kSrc_Mode,      GL_ONE,                 GL_ZERO },
73    { SkXfermode::kDst_Mode,      GL_ZERO,                GL_ONE },
74    { SkXfermode::kSrcOver_Mode,  GL_ONE,                 GL_ONE_MINUS_SRC_ALPHA },
75    { SkXfermode::kDstOver_Mode,  GL_ONE_MINUS_DST_ALPHA, GL_ONE },
76    { SkXfermode::kSrcIn_Mode,    GL_DST_ALPHA,           GL_ZERO },
77    { SkXfermode::kDstIn_Mode,    GL_ZERO,                GL_SRC_ALPHA },
78    { SkXfermode::kSrcOut_Mode,   GL_ONE_MINUS_DST_ALPHA, GL_ZERO },
79    { SkXfermode::kDstOut_Mode,   GL_ZERO,                GL_ONE_MINUS_SRC_ALPHA },
80    { SkXfermode::kSrcATop_Mode,  GL_DST_ALPHA,           GL_ONE_MINUS_SRC_ALPHA },
81    { SkXfermode::kDstATop_Mode,  GL_ONE_MINUS_DST_ALPHA, GL_SRC_ALPHA },
82    { SkXfermode::kXor_Mode,      GL_ONE_MINUS_DST_ALPHA, GL_ONE_MINUS_SRC_ALPHA },
83    { SkXfermode::kPlus_Mode,     GL_ONE,                 GL_ONE },
84    { SkXfermode::kModulate_Mode, GL_ZERO,                GL_SRC_COLOR },
85    { SkXfermode::kScreen_Mode,   GL_ONE,                 GL_ONE_MINUS_SRC_COLOR }
86};
87
88// This array contains the swapped version of each SkXfermode. For instance
89// this array's SrcOver blending mode is actually DstOver. You can refer to
90// createLayer() for more information on the purpose of this array.
91static const Blender gBlendsSwap[] = {
92    { SkXfermode::kClear_Mode,    GL_ONE_MINUS_DST_ALPHA, GL_ZERO },
93    { SkXfermode::kSrc_Mode,      GL_ZERO,                GL_ONE },
94    { SkXfermode::kDst_Mode,      GL_ONE,                 GL_ZERO },
95    { SkXfermode::kSrcOver_Mode,  GL_ONE_MINUS_DST_ALPHA, GL_ONE },
96    { SkXfermode::kDstOver_Mode,  GL_ONE,                 GL_ONE_MINUS_SRC_ALPHA },
97    { SkXfermode::kSrcIn_Mode,    GL_ZERO,                GL_SRC_ALPHA },
98    { SkXfermode::kDstIn_Mode,    GL_DST_ALPHA,           GL_ZERO },
99    { SkXfermode::kSrcOut_Mode,   GL_ZERO,                GL_ONE_MINUS_SRC_ALPHA },
100    { SkXfermode::kDstOut_Mode,   GL_ONE_MINUS_DST_ALPHA, GL_ZERO },
101    { SkXfermode::kSrcATop_Mode,  GL_ONE_MINUS_DST_ALPHA, GL_SRC_ALPHA },
102    { SkXfermode::kDstATop_Mode,  GL_DST_ALPHA,           GL_ONE_MINUS_SRC_ALPHA },
103    { SkXfermode::kXor_Mode,      GL_ONE_MINUS_DST_ALPHA, GL_ONE_MINUS_SRC_ALPHA },
104    { SkXfermode::kPlus_Mode,     GL_ONE,                 GL_ONE },
105    { SkXfermode::kModulate_Mode, GL_DST_COLOR,           GL_ZERO },
106    { SkXfermode::kScreen_Mode,   GL_ONE_MINUS_DST_COLOR, GL_ONE }
107};
108
109///////////////////////////////////////////////////////////////////////////////
110// Constructors/destructor
111///////////////////////////////////////////////////////////////////////////////
112
113OpenGLRenderer::OpenGLRenderer():
114        mCaches(Caches::getInstance()), mExtensions(Extensions::getInstance()) {
115    // *set* draw modifiers to be 0
116    memset(&mDrawModifiers, 0, sizeof(mDrawModifiers));
117    mDrawModifiers.mOverrideLayerAlpha = 1.0f;
118
119    memcpy(mMeshVertices, gMeshVertices, sizeof(gMeshVertices));
120
121    mFirstSnapshot = new Snapshot;
122    mFrameStarted = false;
123
124    mScissorOptimizationDisabled = false;
125}
126
127OpenGLRenderer::~OpenGLRenderer() {
128    // The context has already been destroyed at this point, do not call
129    // GL APIs. All GL state should be kept in Caches.h
130}
131
132void OpenGLRenderer::initProperties() {
133    char property[PROPERTY_VALUE_MAX];
134    if (property_get(PROPERTY_DISABLE_SCISSOR_OPTIMIZATION, property, "false")) {
135        mScissorOptimizationDisabled = !strcasecmp(property, "true");
136        INIT_LOGD("  Scissor optimization %s",
137                mScissorOptimizationDisabled ? "disabled" : "enabled");
138    } else {
139        INIT_LOGD("  Scissor optimization enabled");
140    }
141}
142
143///////////////////////////////////////////////////////////////////////////////
144// Setup
145///////////////////////////////////////////////////////////////////////////////
146
147void OpenGLRenderer::setName(const char* name) {
148    if (name) {
149        mName.setTo(name);
150    } else {
151        mName.clear();
152    }
153}
154
155const char* OpenGLRenderer::getName() const {
156    return mName.string();
157}
158
159bool OpenGLRenderer::isDeferred() {
160    return false;
161}
162
163void OpenGLRenderer::setViewport(int width, int height) {
164    initViewport(width, height);
165
166    glDisable(GL_DITHER);
167    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
168
169    glEnableVertexAttribArray(Program::kBindingPosition);
170}
171
172void OpenGLRenderer::initViewport(int width, int height) {
173    mOrthoMatrix.loadOrtho(0, width, height, 0, -1, 1);
174
175    mWidth = width;
176    mHeight = height;
177
178    mFirstSnapshot->height = height;
179    mFirstSnapshot->viewport.set(0, 0, width, height);
180}
181
182void OpenGLRenderer::setupFrameState(float left, float top,
183        float right, float bottom, bool opaque) {
184    mCaches.clearGarbage();
185
186    mOpaque = opaque;
187    mSnapshot = new Snapshot(mFirstSnapshot,
188            SkCanvas::kMatrix_SaveFlag | SkCanvas::kClip_SaveFlag);
189    mSnapshot->fbo = getTargetFbo();
190    mSaveCount = 1;
191
192    mSnapshot->setClip(left, top, right, bottom);
193    mTilingClip.set(left, top, right, bottom);
194}
195
196status_t OpenGLRenderer::startFrame() {
197    if (mFrameStarted) return DrawGlInfo::kStatusDone;
198    mFrameStarted = true;
199
200    mDirtyClip = true;
201
202    discardFramebuffer(mTilingClip.left, mTilingClip.top, mTilingClip.right, mTilingClip.bottom);
203
204    glViewport(0, 0, mWidth, mHeight);
205
206    // Functors break the tiling extension in pretty spectacular ways
207    // This ensures we don't use tiling when a functor is going to be
208    // invoked during the frame
209    mSuppressTiling = mCaches.hasRegisteredFunctors();
210
211    startTiling(mSnapshot, true);
212
213    debugOverdraw(true, true);
214
215    return clear(mTilingClip.left, mTilingClip.top,
216            mTilingClip.right, mTilingClip.bottom, mOpaque);
217}
218
219status_t OpenGLRenderer::prepare(bool opaque) {
220    return prepareDirty(0.0f, 0.0f, mWidth, mHeight, opaque);
221}
222
223status_t OpenGLRenderer::prepareDirty(float left, float top,
224        float right, float bottom, bool opaque) {
225    setupFrameState(left, top, right, bottom, opaque);
226
227    // Layer renderers will start the frame immediately
228    // The framebuffer renderer will first defer the display list
229    // for each layer and wait until the first drawing command
230    // to start the frame
231    if (mSnapshot->fbo == 0) {
232        syncState();
233        updateLayers();
234    } else {
235        return startFrame();
236    }
237
238    return DrawGlInfo::kStatusDone;
239}
240
241void OpenGLRenderer::discardFramebuffer(float left, float top, float right, float bottom) {
242    // If we know that we are going to redraw the entire framebuffer,
243    // perform a discard to let the driver know we don't need to preserve
244    // the back buffer for this frame.
245    if (mExtensions.hasDiscardFramebuffer() &&
246            left <= 0.0f && top <= 0.0f && right >= mWidth && bottom >= mHeight) {
247        const bool isFbo = getTargetFbo() == 0;
248        const GLenum attachments[] = {
249                isFbo ? (const GLenum) GL_COLOR_EXT : (const GLenum) GL_COLOR_ATTACHMENT0,
250                isFbo ? (const GLenum) GL_STENCIL_EXT : (const GLenum) GL_STENCIL_ATTACHMENT };
251        glDiscardFramebufferEXT(GL_FRAMEBUFFER, 1, attachments);
252    }
253}
254
255status_t OpenGLRenderer::clear(float left, float top, float right, float bottom, bool opaque) {
256    if (!opaque) {
257        mCaches.enableScissor();
258        mCaches.setScissor(left, mSnapshot->height - bottom, right - left, bottom - top);
259        glClear(GL_COLOR_BUFFER_BIT);
260        return DrawGlInfo::kStatusDrew;
261    }
262
263    mCaches.resetScissor();
264    return DrawGlInfo::kStatusDone;
265}
266
267void OpenGLRenderer::syncState() {
268    if (mCaches.blend) {
269        glEnable(GL_BLEND);
270    } else {
271        glDisable(GL_BLEND);
272    }
273}
274
275void OpenGLRenderer::startTiling(const sp<Snapshot>& s, bool opaque) {
276    if (!mSuppressTiling) {
277        Rect* clip = &mTilingClip;
278        if (s->flags & Snapshot::kFlagFboTarget) {
279            clip = &(s->layer->clipRect);
280        }
281
282        startTiling(*clip, s->height, opaque);
283    }
284}
285
286void OpenGLRenderer::startTiling(const Rect& clip, int windowHeight, bool opaque) {
287    if (!mSuppressTiling) {
288        mCaches.startTiling(clip.left, windowHeight - clip.bottom,
289                clip.right - clip.left, clip.bottom - clip.top, opaque);
290    }
291}
292
293void OpenGLRenderer::endTiling() {
294    if (!mSuppressTiling) mCaches.endTiling();
295}
296
297void OpenGLRenderer::finish() {
298    renderOverdraw();
299    endTiling();
300
301    // When finish() is invoked on FBO 0 we've reached the end
302    // of the current frame
303    if (getTargetFbo() == 0) {
304        mCaches.pathCache.trim();
305    }
306
307    if (!suppressErrorChecks()) {
308#if DEBUG_OPENGL
309        GLenum status = GL_NO_ERROR;
310        while ((status = glGetError()) != GL_NO_ERROR) {
311            ALOGD("GL error from OpenGLRenderer: 0x%x", status);
312            switch (status) {
313                case GL_INVALID_ENUM:
314                    ALOGE("  GL_INVALID_ENUM");
315                    break;
316                case GL_INVALID_VALUE:
317                    ALOGE("  GL_INVALID_VALUE");
318                    break;
319                case GL_INVALID_OPERATION:
320                    ALOGE("  GL_INVALID_OPERATION");
321                    break;
322                case GL_OUT_OF_MEMORY:
323                    ALOGE("  Out of memory!");
324                    break;
325            }
326        }
327#endif
328
329#if DEBUG_MEMORY_USAGE
330        mCaches.dumpMemoryUsage();
331#else
332        if (mCaches.getDebugLevel() & kDebugMemory) {
333            mCaches.dumpMemoryUsage();
334        }
335#endif
336    }
337
338    mFrameStarted = false;
339}
340
341void OpenGLRenderer::interrupt() {
342    if (mCaches.currentProgram) {
343        if (mCaches.currentProgram->isInUse()) {
344            mCaches.currentProgram->remove();
345            mCaches.currentProgram = NULL;
346        }
347    }
348    mCaches.unbindMeshBuffer();
349    mCaches.unbindIndicesBuffer();
350    mCaches.resetVertexPointers();
351    mCaches.disableTexCoordsVertexArray();
352    debugOverdraw(false, false);
353}
354
355void OpenGLRenderer::resume() {
356    sp<Snapshot> snapshot = (mSnapshot != NULL) ? mSnapshot : mFirstSnapshot;
357    glViewport(0, 0, snapshot->viewport.getWidth(), snapshot->viewport.getHeight());
358    glBindFramebuffer(GL_FRAMEBUFFER, snapshot->fbo);
359    debugOverdraw(true, false);
360
361    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
362
363    mCaches.scissorEnabled = glIsEnabled(GL_SCISSOR_TEST);
364    mCaches.enableScissor();
365    mCaches.resetScissor();
366    dirtyClip();
367
368    mCaches.activeTexture(0);
369
370    mCaches.blend = true;
371    glEnable(GL_BLEND);
372    glBlendFunc(mCaches.lastSrcMode, mCaches.lastDstMode);
373    glBlendEquation(GL_FUNC_ADD);
374}
375
376void OpenGLRenderer::resumeAfterLayer() {
377    sp<Snapshot> snapshot = (mSnapshot != NULL) ? mSnapshot : mFirstSnapshot;
378    glViewport(0, 0, snapshot->viewport.getWidth(), snapshot->viewport.getHeight());
379    glBindFramebuffer(GL_FRAMEBUFFER, snapshot->fbo);
380    debugOverdraw(true, false);
381
382    mCaches.resetScissor();
383    dirtyClip();
384}
385
386void OpenGLRenderer::detachFunctor(Functor* functor) {
387    mFunctors.remove(functor);
388}
389
390void OpenGLRenderer::attachFunctor(Functor* functor) {
391    mFunctors.add(functor);
392}
393
394status_t OpenGLRenderer::invokeFunctors(Rect& dirty) {
395    status_t result = DrawGlInfo::kStatusDone;
396    size_t count = mFunctors.size();
397
398    if (count > 0) {
399        interrupt();
400        SortedVector<Functor*> functors(mFunctors);
401        mFunctors.clear();
402
403        DrawGlInfo info;
404        info.clipLeft = 0;
405        info.clipTop = 0;
406        info.clipRight = 0;
407        info.clipBottom = 0;
408        info.isLayer = false;
409        info.width = 0;
410        info.height = 0;
411        memset(info.transform, 0, sizeof(float) * 16);
412
413        for (size_t i = 0; i < count; i++) {
414            Functor* f = functors.itemAt(i);
415            result |= (*f)(DrawGlInfo::kModeProcess, &info);
416
417            if (result & DrawGlInfo::kStatusDraw) {
418                Rect localDirty(info.dirtyLeft, info.dirtyTop, info.dirtyRight, info.dirtyBottom);
419                dirty.unionWith(localDirty);
420            }
421
422            if (result & DrawGlInfo::kStatusInvoke) {
423                mFunctors.add(f);
424            }
425        }
426        resume();
427    }
428
429    return result;
430}
431
432status_t OpenGLRenderer::callDrawGLFunction(Functor* functor, Rect& dirty) {
433    if (mSnapshot->isIgnored()) return DrawGlInfo::kStatusDone;
434
435    interrupt();
436    detachFunctor(functor);
437
438    mCaches.enableScissor();
439    if (mDirtyClip) {
440        setScissorFromClip();
441    }
442
443    Rect clip(*mSnapshot->clipRect);
444    clip.snapToPixelBoundaries();
445
446    // Since we don't know what the functor will draw, let's dirty
447    // tne entire clip region
448    if (hasLayer()) {
449        dirtyLayerUnchecked(clip, getRegion());
450    }
451
452    DrawGlInfo info;
453    info.clipLeft = clip.left;
454    info.clipTop = clip.top;
455    info.clipRight = clip.right;
456    info.clipBottom = clip.bottom;
457    info.isLayer = hasLayer();
458    info.width = getSnapshot()->viewport.getWidth();
459    info.height = getSnapshot()->height;
460    getSnapshot()->transform->copyTo(&info.transform[0]);
461
462    status_t result = (*functor)(DrawGlInfo::kModeDraw, &info) | DrawGlInfo::kStatusDrew;
463
464    if (result != DrawGlInfo::kStatusDone) {
465        Rect localDirty(info.dirtyLeft, info.dirtyTop, info.dirtyRight, info.dirtyBottom);
466        dirty.unionWith(localDirty);
467
468        if (result & DrawGlInfo::kStatusInvoke) {
469            mFunctors.add(functor);
470        }
471    }
472
473    resume();
474    return result;
475}
476
477///////////////////////////////////////////////////////////////////////////////
478// Debug
479///////////////////////////////////////////////////////////////////////////////
480
481void OpenGLRenderer::eventMark(const char* name) const {
482    mCaches.eventMark(0, name);
483}
484
485void OpenGLRenderer::startMark(const char* name) const {
486    mCaches.startMark(0, name);
487}
488
489void OpenGLRenderer::endMark() const {
490    mCaches.endMark();
491}
492
493void OpenGLRenderer::debugOverdraw(bool enable, bool clear) {
494    if (mCaches.debugOverdraw && getTargetFbo() == 0) {
495        if (clear) {
496            mCaches.disableScissor();
497            mCaches.stencil.clear();
498        }
499        if (enable) {
500            mCaches.stencil.enableDebugWrite();
501        } else {
502            mCaches.stencil.disable();
503        }
504    }
505}
506
507void OpenGLRenderer::renderOverdraw() {
508    if (mCaches.debugOverdraw && getTargetFbo() == 0) {
509        const Rect* clip = &mTilingClip;
510
511        mCaches.enableScissor();
512        mCaches.setScissor(clip->left, mFirstSnapshot->height - clip->bottom,
513                clip->right - clip->left, clip->bottom - clip->top);
514
515        mCaches.stencil.enableDebugTest(2);
516        drawColor(0x2f0000ff, SkXfermode::kSrcOver_Mode);
517        mCaches.stencil.enableDebugTest(3);
518        drawColor(0x2f00ff00, SkXfermode::kSrcOver_Mode);
519        mCaches.stencil.enableDebugTest(4);
520        drawColor(0x3fff0000, SkXfermode::kSrcOver_Mode);
521        mCaches.stencil.enableDebugTest(4, true);
522        drawColor(0x7fff0000, SkXfermode::kSrcOver_Mode);
523        mCaches.stencil.disable();
524    }
525}
526
527///////////////////////////////////////////////////////////////////////////////
528// Layers
529///////////////////////////////////////////////////////////////////////////////
530
531bool OpenGLRenderer::updateLayer(Layer* layer, bool inFrame) {
532    if (layer->deferredUpdateScheduled && layer->renderer &&
533            layer->displayList && layer->displayList->isRenderable()) {
534        Rect& dirty = layer->dirtyRect;
535
536        if (inFrame) {
537            endTiling();
538            debugOverdraw(false, false);
539        }
540
541        if (CC_UNLIKELY(inFrame || mCaches.drawDeferDisabled)) {
542            layer->render();
543        } else {
544            layer->defer();
545        }
546
547        if (inFrame) {
548            resumeAfterLayer();
549            startTiling(mSnapshot);
550        }
551
552        layer->debugDrawUpdate = mCaches.debugLayersUpdates;
553        layer->hasDrawnSinceUpdate = false;
554
555        return true;
556    }
557
558    return false;
559}
560
561void OpenGLRenderer::updateLayers() {
562    // If draw deferring is enabled this method will simply defer
563    // the display list of each individual layer. The layers remain
564    // in the layer updates list which will be cleared by flushLayers().
565    int count = mLayerUpdates.size();
566    if (count > 0) {
567        if (CC_UNLIKELY(mCaches.drawDeferDisabled)) {
568            startMark("Layer Updates");
569        } else {
570            startMark("Defer Layer Updates");
571        }
572
573        // Note: it is very important to update the layers in order
574        for (int i = 0; i < count; i++) {
575            Layer* layer = mLayerUpdates.itemAt(i);
576            updateLayer(layer, false);
577            if (CC_UNLIKELY(mCaches.drawDeferDisabled)) {
578                mCaches.resourceCache.decrementRefcount(layer);
579            }
580        }
581
582        if (CC_UNLIKELY(mCaches.drawDeferDisabled)) {
583            mLayerUpdates.clear();
584            glBindFramebuffer(GL_FRAMEBUFFER, getTargetFbo());
585        }
586        endMark();
587    }
588}
589
590void OpenGLRenderer::flushLayers() {
591    int count = mLayerUpdates.size();
592    if (count > 0) {
593        startMark("Apply Layer Updates");
594        char layerName[12];
595
596        // Note: it is very important to update the layers in order
597        for (int i = 0; i < count; i++) {
598            sprintf(layerName, "Layer #%d", i);
599            startMark(layerName);
600
601            Layer* layer = mLayerUpdates.itemAt(i);
602            layer->flush();
603            mCaches.resourceCache.decrementRefcount(layer);
604
605            endMark();
606        }
607
608        mLayerUpdates.clear();
609        glBindFramebuffer(GL_FRAMEBUFFER, getTargetFbo());
610
611        endMark();
612    }
613}
614
615void OpenGLRenderer::pushLayerUpdate(Layer* layer) {
616    if (layer) {
617        // Make sure we don't introduce duplicates.
618        // SortedVector would do this automatically but we need to respect
619        // the insertion order. The linear search is not an issue since
620        // this list is usually very short (typically one item, at most a few)
621        for (int i = mLayerUpdates.size() - 1; i >= 0; i--) {
622            if (mLayerUpdates.itemAt(i) == layer) {
623                return;
624            }
625        }
626        mLayerUpdates.push_back(layer);
627        mCaches.resourceCache.incrementRefcount(layer);
628    }
629}
630
631void OpenGLRenderer::clearLayerUpdates() {
632    size_t count = mLayerUpdates.size();
633    if (count > 0) {
634        mCaches.resourceCache.lock();
635        for (size_t i = 0; i < count; i++) {
636            mCaches.resourceCache.decrementRefcountLocked(mLayerUpdates.itemAt(i));
637        }
638        mCaches.resourceCache.unlock();
639        mLayerUpdates.clear();
640    }
641}
642
643///////////////////////////////////////////////////////////////////////////////
644// State management
645///////////////////////////////////////////////////////////////////////////////
646
647int OpenGLRenderer::getSaveCount() const {
648    return mSaveCount;
649}
650
651int OpenGLRenderer::save(int flags) {
652    return saveSnapshot(flags);
653}
654
655void OpenGLRenderer::restore() {
656    if (mSaveCount > 1) {
657        restoreSnapshot();
658    }
659}
660
661void OpenGLRenderer::restoreToCount(int saveCount) {
662    if (saveCount < 1) saveCount = 1;
663
664    while (mSaveCount > saveCount) {
665        restoreSnapshot();
666    }
667}
668
669int OpenGLRenderer::saveSnapshot(int flags) {
670    mSnapshot = new Snapshot(mSnapshot, flags);
671    return mSaveCount++;
672}
673
674bool OpenGLRenderer::restoreSnapshot() {
675    bool restoreClip = mSnapshot->flags & Snapshot::kFlagClipSet;
676    bool restoreLayer = mSnapshot->flags & Snapshot::kFlagIsLayer;
677    bool restoreOrtho = mSnapshot->flags & Snapshot::kFlagDirtyOrtho;
678
679    sp<Snapshot> current = mSnapshot;
680    sp<Snapshot> previous = mSnapshot->previous;
681
682    if (restoreOrtho) {
683        Rect& r = previous->viewport;
684        glViewport(r.left, r.top, r.right, r.bottom);
685        mOrthoMatrix.load(current->orthoMatrix);
686    }
687
688    mSaveCount--;
689    mSnapshot = previous;
690
691    if (restoreClip) {
692        dirtyClip();
693    }
694
695    if (restoreLayer) {
696        endMark(); // Savelayer
697        startMark("ComposeLayer");
698        composeLayer(current, previous);
699        endMark();
700    }
701
702    return restoreClip;
703}
704
705///////////////////////////////////////////////////////////////////////////////
706// Layers
707///////////////////////////////////////////////////////////////////////////////
708
709int OpenGLRenderer::saveLayer(float left, float top, float right, float bottom,
710        int alpha, SkXfermode::Mode mode, int flags) {
711    const GLuint previousFbo = mSnapshot->fbo;
712    const int count = saveSnapshot(flags);
713
714    if (!mSnapshot->isIgnored()) {
715        createLayer(left, top, right, bottom, alpha, mode, flags, previousFbo);
716    }
717
718    return count;
719}
720
721void OpenGLRenderer::calculateLayerBoundsAndClip(Rect& bounds, Rect& clip, bool fboLayer) {
722    const Rect untransformedBounds(bounds);
723
724    currentTransform().mapRect(bounds);
725
726    // Layers only make sense if they are in the framebuffer's bounds
727    if (bounds.intersect(*mSnapshot->clipRect)) {
728        // We cannot work with sub-pixels in this case
729        bounds.snapToPixelBoundaries();
730
731        // When the layer is not an FBO, we may use glCopyTexImage so we
732        // need to make sure the layer does not extend outside the bounds
733        // of the framebuffer
734        if (!bounds.intersect(mSnapshot->previous->viewport)) {
735            bounds.setEmpty();
736        } else if (fboLayer) {
737            clip.set(bounds);
738            mat4 inverse;
739            inverse.loadInverse(currentTransform());
740            inverse.mapRect(clip);
741            clip.snapToPixelBoundaries();
742            if (clip.intersect(untransformedBounds)) {
743                clip.translate(-untransformedBounds.left, -untransformedBounds.top);
744                bounds.set(untransformedBounds);
745            } else {
746                clip.setEmpty();
747            }
748        }
749    } else {
750        bounds.setEmpty();
751    }
752}
753
754void OpenGLRenderer::updateSnapshotIgnoreForLayer(const Rect& bounds, const Rect& clip,
755        bool fboLayer, int alpha) {
756    if (bounds.isEmpty() || bounds.getWidth() > mCaches.maxTextureSize ||
757            bounds.getHeight() > mCaches.maxTextureSize ||
758            (fboLayer && clip.isEmpty())) {
759        mSnapshot->empty = fboLayer;
760    } else {
761        mSnapshot->invisible = mSnapshot->invisible || (alpha <= ALPHA_THRESHOLD && fboLayer);
762    }
763}
764
765int OpenGLRenderer::saveLayerDeferred(float left, float top, float right, float bottom,
766        int alpha, SkXfermode::Mode mode, int flags) {
767    const GLuint previousFbo = mSnapshot->fbo;
768    const int count = saveSnapshot(flags);
769
770    if (!mSnapshot->isIgnored() && (flags & SkCanvas::kClipToLayer_SaveFlag)) {
771        // initialize the snapshot as though it almost represents an FBO layer so deferred draw
772        // operations will be able to store and restore the current clip and transform info, and
773        // quick rejection will be correct (for display lists)
774
775        Rect bounds(left, top, right, bottom);
776        Rect clip;
777        calculateLayerBoundsAndClip(bounds, clip, true);
778        updateSnapshotIgnoreForLayer(bounds, clip, true, alpha);
779
780        if (!mSnapshot->isIgnored()) {
781            mSnapshot->resetTransform(-bounds.left, -bounds.top, 0.0f);
782            mSnapshot->resetClip(clip.left, clip.top, clip.right, clip.bottom);
783        }
784    }
785
786    return count;
787}
788
789
790/**
791 * Layers are viewed by Skia are slightly different than layers in image editing
792 * programs (for instance.) When a layer is created, previously created layers
793 * and the frame buffer still receive every drawing command. For instance, if a
794 * layer is created and a shape intersecting the bounds of the layers and the
795 * framebuffer is draw, the shape will be drawn on both (unless the layer was
796 * created with the SkCanvas::kClipToLayer_SaveFlag flag.)
797 *
798 * A way to implement layers is to create an FBO for each layer, backed by an RGBA
799 * texture. Unfortunately, this is inefficient as it requires every primitive to
800 * be drawn n + 1 times, where n is the number of active layers. In practice this
801 * means, for every primitive:
802 *   - Switch active frame buffer
803 *   - Change viewport, clip and projection matrix
804 *   - Issue the drawing
805 *
806 * Switching rendering target n + 1 times per drawn primitive is extremely costly.
807 * To avoid this, layers are implemented in a different way here, at least in the
808 * general case. FBOs are used, as an optimization, when the "clip to layer" flag
809 * is set. When this flag is set we can redirect all drawing operations into a
810 * single FBO.
811 *
812 * This implementation relies on the frame buffer being at least RGBA 8888. When
813 * a layer is created, only a texture is created, not an FBO. The content of the
814 * frame buffer contained within the layer's bounds is copied into this texture
815 * using glCopyTexImage2D(). The layer's region is then cleared(1) in the frame
816 * buffer and drawing continues as normal. This technique therefore treats the
817 * frame buffer as a scratch buffer for the layers.
818 *
819 * To compose the layers back onto the frame buffer, each layer texture
820 * (containing the original frame buffer data) is drawn as a simple quad over
821 * the frame buffer. The trick is that the quad is set as the composition
822 * destination in the blending equation, and the frame buffer becomes the source
823 * of the composition.
824 *
825 * Drawing layers with an alpha value requires an extra step before composition.
826 * An empty quad is drawn over the layer's region in the frame buffer. This quad
827 * is drawn with the rgba color (0,0,0,alpha). The alpha value offered by the
828 * quad is used to multiply the colors in the frame buffer. This is achieved by
829 * changing the GL blend functions for the GL_FUNC_ADD blend equation to
830 * GL_ZERO, GL_SRC_ALPHA.
831 *
832 * Because glCopyTexImage2D() can be slow, an alternative implementation might
833 * be use to draw a single clipped layer. The implementation described above
834 * is correct in every case.
835 *
836 * (1) The frame buffer is actually not cleared right away. To allow the GPU
837 *     to potentially optimize series of calls to glCopyTexImage2D, the frame
838 *     buffer is left untouched until the first drawing operation. Only when
839 *     something actually gets drawn are the layers regions cleared.
840 */
841bool OpenGLRenderer::createLayer(float left, float top, float right, float bottom,
842        int alpha, SkXfermode::Mode mode, int flags, GLuint previousFbo) {
843    LAYER_LOGD("Requesting layer %.2fx%.2f", right - left, bottom - top);
844    LAYER_LOGD("Layer cache size = %d", mCaches.layerCache.getSize());
845
846    const bool fboLayer = flags & SkCanvas::kClipToLayer_SaveFlag;
847
848    // Window coordinates of the layer
849    Rect clip;
850    Rect bounds(left, top, right, bottom);
851    calculateLayerBoundsAndClip(bounds, clip, fboLayer);
852    updateSnapshotIgnoreForLayer(bounds, clip, fboLayer, alpha);
853
854    // Bail out if we won't draw in this snapshot
855    if (mSnapshot->isIgnored()) {
856        return false;
857    }
858
859    mCaches.activeTexture(0);
860    Layer* layer = mCaches.layerCache.get(bounds.getWidth(), bounds.getHeight());
861    if (!layer) {
862        return false;
863    }
864
865    layer->setAlpha(alpha, mode);
866    layer->layer.set(bounds);
867    layer->texCoords.set(0.0f, bounds.getHeight() / float(layer->getHeight()),
868            bounds.getWidth() / float(layer->getWidth()), 0.0f);
869    layer->setColorFilter(mDrawModifiers.mColorFilter);
870    layer->setBlend(true);
871    layer->setDirty(false);
872
873    // Save the layer in the snapshot
874    mSnapshot->flags |= Snapshot::kFlagIsLayer;
875    mSnapshot->layer = layer;
876
877    startMark("SaveLayer");
878    if (fboLayer) {
879        return createFboLayer(layer, bounds, clip, previousFbo);
880    } else {
881        // Copy the framebuffer into the layer
882        layer->bindTexture();
883        if (!bounds.isEmpty()) {
884            if (layer->isEmpty()) {
885                glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA,
886                        bounds.left, mSnapshot->height - bounds.bottom,
887                        layer->getWidth(), layer->getHeight(), 0);
888                layer->setEmpty(false);
889            } else {
890                glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, bounds.left,
891                        mSnapshot->height - bounds.bottom, bounds.getWidth(), bounds.getHeight());
892            }
893
894            // Enqueue the buffer coordinates to clear the corresponding region later
895            mLayers.push(new Rect(bounds));
896        }
897    }
898
899    return true;
900}
901
902bool OpenGLRenderer::createFboLayer(Layer* layer, Rect& bounds, Rect& clip, GLuint previousFbo) {
903    layer->clipRect.set(clip);
904    layer->setFbo(mCaches.fboCache.get());
905
906    mSnapshot->region = &mSnapshot->layer->region;
907    mSnapshot->flags |= Snapshot::kFlagFboTarget | Snapshot::kFlagIsFboLayer |
908            Snapshot::kFlagDirtyOrtho;
909    mSnapshot->fbo = layer->getFbo();
910    mSnapshot->resetTransform(-bounds.left, -bounds.top, 0.0f);
911    mSnapshot->resetClip(clip.left, clip.top, clip.right, clip.bottom);
912    mSnapshot->viewport.set(0.0f, 0.0f, bounds.getWidth(), bounds.getHeight());
913    mSnapshot->height = bounds.getHeight();
914    mSnapshot->orthoMatrix.load(mOrthoMatrix);
915
916    endTiling();
917    debugOverdraw(false, false);
918    // Bind texture to FBO
919    glBindFramebuffer(GL_FRAMEBUFFER, layer->getFbo());
920    layer->bindTexture();
921
922    // Initialize the texture if needed
923    if (layer->isEmpty()) {
924        layer->allocateTexture();
925        layer->setEmpty(false);
926    }
927
928    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
929            layer->getTexture(), 0);
930
931    startTiling(mSnapshot, true);
932
933    // Clear the FBO, expand the clear region by 1 to get nice bilinear filtering
934    mCaches.enableScissor();
935    mCaches.setScissor(clip.left - 1.0f, bounds.getHeight() - clip.bottom - 1.0f,
936            clip.getWidth() + 2.0f, clip.getHeight() + 2.0f);
937    glClear(GL_COLOR_BUFFER_BIT);
938
939    dirtyClip();
940
941    // Change the ortho projection
942    glViewport(0, 0, bounds.getWidth(), bounds.getHeight());
943    mOrthoMatrix.loadOrtho(0.0f, bounds.getWidth(), bounds.getHeight(), 0.0f, -1.0f, 1.0f);
944
945    return true;
946}
947
948/**
949 * Read the documentation of createLayer() before doing anything in this method.
950 */
951void OpenGLRenderer::composeLayer(sp<Snapshot> current, sp<Snapshot> previous) {
952    if (!current->layer) {
953        ALOGE("Attempting to compose a layer that does not exist");
954        return;
955    }
956
957    Layer* layer = current->layer;
958    const Rect& rect = layer->layer;
959    const bool fboLayer = current->flags & Snapshot::kFlagIsFboLayer;
960
961    if (fboLayer) {
962        endTiling();
963
964        // Detach the texture from the FBO
965        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 0, 0);
966
967        layer->removeFbo(false);
968
969        // Unbind current FBO and restore previous one
970        glBindFramebuffer(GL_FRAMEBUFFER, previous->fbo);
971        debugOverdraw(true, false);
972
973        startTiling(previous);
974    }
975
976    if (!fboLayer && layer->getAlpha() < 255) {
977        drawColorRect(rect.left, rect.top, rect.right, rect.bottom,
978                layer->getAlpha() << 24, SkXfermode::kDstIn_Mode, true);
979        // Required below, composeLayerRect() will divide by 255
980        layer->setAlpha(255);
981    }
982
983    mCaches.unbindMeshBuffer();
984
985    mCaches.activeTexture(0);
986
987    // When the layer is stored in an FBO, we can save a bit of fillrate by
988    // drawing only the dirty region
989    if (fboLayer) {
990        dirtyLayer(rect.left, rect.top, rect.right, rect.bottom, *previous->transform);
991        if (layer->getColorFilter()) {
992            setupColorFilter(layer->getColorFilter());
993        }
994        composeLayerRegion(layer, rect);
995        if (layer->getColorFilter()) {
996            resetColorFilter();
997        }
998    } else if (!rect.isEmpty()) {
999        dirtyLayer(rect.left, rect.top, rect.right, rect.bottom);
1000        composeLayerRect(layer, rect, true);
1001    }
1002
1003    dirtyClip();
1004
1005    // Failing to add the layer to the cache should happen only if the layer is too large
1006    if (!mCaches.layerCache.put(layer)) {
1007        LAYER_LOGD("Deleting layer");
1008        Caches::getInstance().resourceCache.decrementRefcount(layer);
1009    }
1010}
1011
1012void OpenGLRenderer::drawTextureLayer(Layer* layer, const Rect& rect) {
1013    float alpha = layer->getAlpha() / 255.0f * mSnapshot->alpha;
1014
1015    setupDraw();
1016    if (layer->getRenderTarget() == GL_TEXTURE_2D) {
1017        setupDrawWithTexture();
1018    } else {
1019        setupDrawWithExternalTexture();
1020    }
1021    setupDrawTextureTransform();
1022    setupDrawColor(alpha, alpha, alpha, alpha);
1023    setupDrawColorFilter();
1024    setupDrawBlending(layer->isBlend() || alpha < 1.0f, layer->getMode());
1025    setupDrawProgram();
1026    setupDrawPureColorUniforms();
1027    setupDrawColorFilterUniforms();
1028    if (layer->getRenderTarget() == GL_TEXTURE_2D) {
1029        setupDrawTexture(layer->getTexture());
1030    } else {
1031        setupDrawExternalTexture(layer->getTexture());
1032    }
1033    if (currentTransform().isPureTranslate() &&
1034            layer->getWidth() == (uint32_t) rect.getWidth() &&
1035            layer->getHeight() == (uint32_t) rect.getHeight()) {
1036        const float x = (int) floorf(rect.left + currentTransform().getTranslateX() + 0.5f);
1037        const float y = (int) floorf(rect.top + currentTransform().getTranslateY() + 0.5f);
1038
1039        layer->setFilter(GL_NEAREST);
1040        setupDrawModelView(x, y, x + rect.getWidth(), y + rect.getHeight(), true);
1041    } else {
1042        layer->setFilter(GL_LINEAR);
1043        setupDrawModelView(rect.left, rect.top, rect.right, rect.bottom);
1044    }
1045    setupDrawTextureTransformUniforms(layer->getTexTransform());
1046    setupDrawMesh(&mMeshVertices[0].position[0], &mMeshVertices[0].texture[0]);
1047
1048    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
1049
1050    finishDrawTexture();
1051}
1052
1053void OpenGLRenderer::composeLayerRect(Layer* layer, const Rect& rect, bool swap) {
1054    if (!layer->isTextureLayer()) {
1055        const Rect& texCoords = layer->texCoords;
1056        resetDrawTextureTexCoords(texCoords.left, texCoords.top,
1057                texCoords.right, texCoords.bottom);
1058
1059        float x = rect.left;
1060        float y = rect.top;
1061        bool simpleTransform = currentTransform().isPureTranslate() &&
1062                layer->getWidth() == (uint32_t) rect.getWidth() &&
1063                layer->getHeight() == (uint32_t) rect.getHeight();
1064
1065        if (simpleTransform) {
1066            // When we're swapping, the layer is already in screen coordinates
1067            if (!swap) {
1068                x = (int) floorf(rect.left + currentTransform().getTranslateX() + 0.5f);
1069                y = (int) floorf(rect.top + currentTransform().getTranslateY() + 0.5f);
1070            }
1071
1072            layer->setFilter(GL_NEAREST, true);
1073        } else {
1074            layer->setFilter(GL_LINEAR, true);
1075        }
1076
1077        float alpha = getLayerAlpha(layer);
1078        bool blend = layer->isBlend() || alpha < 1.0f;
1079        drawTextureMesh(x, y, x + rect.getWidth(), y + rect.getHeight(),
1080                layer->getTexture(), alpha, layer->getMode(), blend,
1081                &mMeshVertices[0].position[0], &mMeshVertices[0].texture[0],
1082                GL_TRIANGLE_STRIP, gMeshCount, swap, swap || simpleTransform);
1083
1084        resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
1085    } else {
1086        resetDrawTextureTexCoords(0.0f, 1.0f, 1.0f, 0.0f);
1087        drawTextureLayer(layer, rect);
1088        resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
1089    }
1090}
1091
1092/**
1093 * Issues the command X, and if we're composing a save layer to the fbo or drawing a newly updated
1094 * hardware layer with overdraw debug on, draws again to the stencil only, so that these draw
1095 * operations are correctly counted twice for overdraw. NOTE: assumes composeLayerRegion only used
1096 * by saveLayer's restore
1097 */
1098#define DRAW_DOUBLE_STENCIL_IF(COND, DRAW_COMMAND) {                             \
1099        DRAW_COMMAND;                                                            \
1100        if (CC_UNLIKELY(mCaches.debugOverdraw && getTargetFbo() == 0 && COND)) { \
1101            glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);                 \
1102            DRAW_COMMAND;                                                        \
1103            glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);                     \
1104        }                                                                        \
1105    }
1106
1107#define DRAW_DOUBLE_STENCIL(DRAW_COMMAND) DRAW_DOUBLE_STENCIL_IF(true, DRAW_COMMAND)
1108
1109void OpenGLRenderer::composeLayerRegion(Layer* layer, const Rect& rect) {
1110    if (layer->region.isRect()) {
1111        layer->setRegionAsRect();
1112
1113        DRAW_DOUBLE_STENCIL(composeLayerRect(layer, layer->regionRect));
1114
1115        layer->region.clear();
1116        return;
1117    }
1118
1119    // TODO: See LayerRenderer.cpp::generateMesh() for important
1120    //       information about this implementation
1121    if (CC_LIKELY(!layer->region.isEmpty())) {
1122        size_t count;
1123        const android::Rect* rects;
1124        Region safeRegion;
1125        if (CC_LIKELY(hasRectToRectTransform())) {
1126            rects = layer->region.getArray(&count);
1127        } else {
1128            safeRegion = Region::createTJunctionFreeRegion(layer->region);
1129            rects = safeRegion.getArray(&count);
1130        }
1131
1132        const float alpha = getLayerAlpha(layer);
1133        const float texX = 1.0f / float(layer->getWidth());
1134        const float texY = 1.0f / float(layer->getHeight());
1135        const float height = rect.getHeight();
1136
1137        setupDraw();
1138
1139        // We must get (and therefore bind) the region mesh buffer
1140        // after we setup drawing in case we need to mess with the
1141        // stencil buffer in setupDraw()
1142        TextureVertex* mesh = mCaches.getRegionMesh();
1143        GLsizei numQuads = 0;
1144
1145        setupDrawWithTexture();
1146        setupDrawColor(alpha, alpha, alpha, alpha);
1147        setupDrawColorFilter();
1148        setupDrawBlending(layer->isBlend() || alpha < 1.0f, layer->getMode(), false);
1149        setupDrawProgram();
1150        setupDrawDirtyRegionsDisabled();
1151        setupDrawPureColorUniforms();
1152        setupDrawColorFilterUniforms();
1153        setupDrawTexture(layer->getTexture());
1154        if (currentTransform().isPureTranslate()) {
1155            const float x = (int) floorf(rect.left + currentTransform().getTranslateX() + 0.5f);
1156            const float y = (int) floorf(rect.top + currentTransform().getTranslateY() + 0.5f);
1157
1158            layer->setFilter(GL_NEAREST);
1159            setupDrawModelViewTranslate(x, y, x + rect.getWidth(), y + rect.getHeight(), true);
1160        } else {
1161            layer->setFilter(GL_LINEAR);
1162            setupDrawModelViewTranslate(rect.left, rect.top, rect.right, rect.bottom);
1163        }
1164        setupDrawMeshIndices(&mesh[0].position[0], &mesh[0].texture[0]);
1165
1166        for (size_t i = 0; i < count; i++) {
1167            const android::Rect* r = &rects[i];
1168
1169            const float u1 = r->left * texX;
1170            const float v1 = (height - r->top) * texY;
1171            const float u2 = r->right * texX;
1172            const float v2 = (height - r->bottom) * texY;
1173
1174            // TODO: Reject quads outside of the clip
1175            TextureVertex::set(mesh++, r->left, r->top, u1, v1);
1176            TextureVertex::set(mesh++, r->right, r->top, u2, v1);
1177            TextureVertex::set(mesh++, r->left, r->bottom, u1, v2);
1178            TextureVertex::set(mesh++, r->right, r->bottom, u2, v2);
1179
1180            numQuads++;
1181
1182            if (numQuads >= REGION_MESH_QUAD_COUNT) {
1183                DRAW_DOUBLE_STENCIL(glDrawElements(GL_TRIANGLES, numQuads * 6,
1184                                GL_UNSIGNED_SHORT, NULL));
1185                numQuads = 0;
1186                mesh = mCaches.getRegionMesh();
1187            }
1188        }
1189
1190        if (numQuads > 0) {
1191            DRAW_DOUBLE_STENCIL(glDrawElements(GL_TRIANGLES, numQuads * 6,
1192                            GL_UNSIGNED_SHORT, NULL));
1193        }
1194
1195        finishDrawTexture();
1196
1197#if DEBUG_LAYERS_AS_REGIONS
1198        drawRegionRects(layer->region);
1199#endif
1200
1201        layer->region.clear();
1202    }
1203}
1204
1205void OpenGLRenderer::drawRegionRects(const Region& region) {
1206#if DEBUG_LAYERS_AS_REGIONS
1207    size_t count;
1208    const android::Rect* rects = region.getArray(&count);
1209
1210    uint32_t colors[] = {
1211            0x7fff0000, 0x7f00ff00,
1212            0x7f0000ff, 0x7fff00ff,
1213    };
1214
1215    int offset = 0;
1216    int32_t top = rects[0].top;
1217
1218    for (size_t i = 0; i < count; i++) {
1219        if (top != rects[i].top) {
1220            offset ^= 0x2;
1221            top = rects[i].top;
1222        }
1223
1224        Rect r(rects[i].left, rects[i].top, rects[i].right, rects[i].bottom);
1225        drawColorRect(r.left, r.top, r.right, r.bottom, colors[offset + (i & 0x1)],
1226                SkXfermode::kSrcOver_Mode);
1227    }
1228#endif
1229}
1230
1231void OpenGLRenderer::drawRegionRects(const SkRegion& region, int color,
1232        SkXfermode::Mode mode, bool dirty) {
1233    int count = 0;
1234    Vector<float> rects;
1235
1236    SkRegion::Iterator it(region);
1237    while (!it.done()) {
1238        const SkIRect& r = it.rect();
1239        rects.push(r.fLeft);
1240        rects.push(r.fTop);
1241        rects.push(r.fRight);
1242        rects.push(r.fBottom);
1243        count += 4;
1244        it.next();
1245    }
1246
1247    drawColorRects(rects.array(), count, color, mode, true, dirty, false);
1248}
1249
1250void OpenGLRenderer::dirtyLayer(const float left, const float top,
1251        const float right, const float bottom, const mat4 transform) {
1252    if (hasLayer()) {
1253        Rect bounds(left, top, right, bottom);
1254        transform.mapRect(bounds);
1255        dirtyLayerUnchecked(bounds, getRegion());
1256    }
1257}
1258
1259void OpenGLRenderer::dirtyLayer(const float left, const float top,
1260        const float right, const float bottom) {
1261    if (hasLayer()) {
1262        Rect bounds(left, top, right, bottom);
1263        dirtyLayerUnchecked(bounds, getRegion());
1264    }
1265}
1266
1267void OpenGLRenderer::dirtyLayerUnchecked(Rect& bounds, Region* region) {
1268    if (bounds.intersect(*mSnapshot->clipRect)) {
1269        bounds.snapToPixelBoundaries();
1270        android::Rect dirty(bounds.left, bounds.top, bounds.right, bounds.bottom);
1271        if (!dirty.isEmpty()) {
1272            region->orSelf(dirty);
1273        }
1274    }
1275}
1276
1277void OpenGLRenderer::clearLayerRegions() {
1278    const size_t count = mLayers.size();
1279    if (count == 0) return;
1280
1281    if (!mSnapshot->isIgnored()) {
1282        // Doing several glScissor/glClear here can negatively impact
1283        // GPUs with a tiler architecture, instead we draw quads with
1284        // the Clear blending mode
1285
1286        // The list contains bounds that have already been clipped
1287        // against their initial clip rect, and the current clip
1288        // is likely different so we need to disable clipping here
1289        bool scissorChanged = mCaches.disableScissor();
1290
1291        Vertex mesh[count * 6];
1292        Vertex* vertex = mesh;
1293
1294        for (uint32_t i = 0; i < count; i++) {
1295            Rect* bounds = mLayers.itemAt(i);
1296
1297            Vertex::set(vertex++, bounds->left, bounds->bottom);
1298            Vertex::set(vertex++, bounds->left, bounds->top);
1299            Vertex::set(vertex++, bounds->right, bounds->top);
1300            Vertex::set(vertex++, bounds->left, bounds->bottom);
1301            Vertex::set(vertex++, bounds->right, bounds->top);
1302            Vertex::set(vertex++, bounds->right, bounds->bottom);
1303
1304            delete bounds;
1305        }
1306        // We must clear the list of dirty rects before we
1307        // call setupDraw() to prevent stencil setup to do
1308        // the same thing again
1309        mLayers.clear();
1310
1311        setupDraw(false);
1312        setupDrawColor(0.0f, 0.0f, 0.0f, 1.0f);
1313        setupDrawBlending(true, SkXfermode::kClear_Mode);
1314        setupDrawProgram();
1315        setupDrawPureColorUniforms();
1316        setupDrawModelViewTranslate(0.0f, 0.0f, 0.0f, 0.0f, true);
1317        setupDrawVertices(&mesh[0].position[0]);
1318
1319        glDrawArrays(GL_TRIANGLES, 0, count * 6);
1320
1321        if (scissorChanged) mCaches.enableScissor();
1322    } else {
1323        for (uint32_t i = 0; i < count; i++) {
1324            delete mLayers.itemAt(i);
1325        }
1326        mLayers.clear();
1327    }
1328}
1329
1330///////////////////////////////////////////////////////////////////////////////
1331// State Deferral
1332///////////////////////////////////////////////////////////////////////////////
1333
1334bool OpenGLRenderer::storeDisplayState(DeferredDisplayState& state, int stateDeferFlags) {
1335    const Rect& currentClip = *(mSnapshot->clipRect);
1336    const mat4& currentMatrix = *(mSnapshot->transform);
1337
1338    if (stateDeferFlags & kStateDeferFlag_Draw) {
1339        // state has bounds initialized in local coordinates
1340        if (!state.mBounds.isEmpty()) {
1341            currentMatrix.mapRect(state.mBounds);
1342            if (!state.mBounds.intersect(currentClip)) {
1343                // quick rejected
1344                return true;
1345            }
1346        } else {
1347            state.mBounds.set(currentClip);
1348        }
1349    }
1350
1351    state.mClipValid = (stateDeferFlags & kStateDeferFlag_Clip);
1352    if (state.mClipValid) {
1353        state.mClip.set(currentClip);
1354    }
1355
1356    // Transform, drawModifiers, and alpha always deferred, since they are used by state operations
1357    // (Note: saveLayer/restore use colorFilter and alpha, so we just save restore everything)
1358    state.mMatrix.load(currentMatrix);
1359    state.mDrawModifiers = mDrawModifiers;
1360    state.mAlpha = mSnapshot->alpha;
1361    return false;
1362}
1363
1364void OpenGLRenderer::restoreDisplayState(const DeferredDisplayState& state, bool skipClipRestore) {
1365    currentTransform().load(state.mMatrix);
1366    mDrawModifiers = state.mDrawModifiers;
1367    mSnapshot->alpha = state.mAlpha;
1368
1369    if (state.mClipValid && !skipClipRestore) {
1370        mSnapshot->setClip(state.mClip.left, state.mClip.top, state.mClip.right, state.mClip.bottom);
1371        dirtyClip();
1372    }
1373}
1374
1375void OpenGLRenderer::setFullScreenClip() {
1376    mSnapshot->setClip(0, 0, mWidth, mHeight);
1377    dirtyClip();
1378}
1379
1380///////////////////////////////////////////////////////////////////////////////
1381// Transforms
1382///////////////////////////////////////////////////////////////////////////////
1383
1384void OpenGLRenderer::translate(float dx, float dy) {
1385    currentTransform().translate(dx, dy, 0.0f);
1386}
1387
1388void OpenGLRenderer::rotate(float degrees) {
1389    currentTransform().rotate(degrees, 0.0f, 0.0f, 1.0f);
1390}
1391
1392void OpenGLRenderer::scale(float sx, float sy) {
1393    currentTransform().scale(sx, sy, 1.0f);
1394}
1395
1396void OpenGLRenderer::skew(float sx, float sy) {
1397    currentTransform().skew(sx, sy);
1398}
1399
1400void OpenGLRenderer::setMatrix(SkMatrix* matrix) {
1401    if (matrix) {
1402        currentTransform().load(*matrix);
1403    } else {
1404        currentTransform().loadIdentity();
1405    }
1406}
1407
1408bool OpenGLRenderer::hasRectToRectTransform() {
1409    return CC_LIKELY(currentTransform().rectToRect());
1410}
1411
1412void OpenGLRenderer::getMatrix(SkMatrix* matrix) {
1413    currentTransform().copyTo(*matrix);
1414}
1415
1416void OpenGLRenderer::concatMatrix(SkMatrix* matrix) {
1417    SkMatrix transform;
1418    currentTransform().copyTo(transform);
1419    transform.preConcat(*matrix);
1420    currentTransform().load(transform);
1421}
1422
1423///////////////////////////////////////////////////////////////////////////////
1424// Clipping
1425///////////////////////////////////////////////////////////////////////////////
1426
1427void OpenGLRenderer::setScissorFromClip() {
1428    Rect clip(*mSnapshot->clipRect);
1429    clip.snapToPixelBoundaries();
1430
1431    if (mCaches.setScissor(clip.left, mSnapshot->height - clip.bottom,
1432            clip.getWidth(), clip.getHeight())) {
1433        mDirtyClip = false;
1434    }
1435}
1436
1437void OpenGLRenderer::ensureStencilBuffer() {
1438    // Thanks to the mismatch between EGL and OpenGL ES FBO we
1439    // cannot attach a stencil buffer to fbo0 dynamically. Let's
1440    // just hope we have one when hasLayer() returns false.
1441    if (hasLayer()) {
1442        attachStencilBufferToLayer(mSnapshot->layer);
1443    }
1444}
1445
1446void OpenGLRenderer::attachStencilBufferToLayer(Layer* layer) {
1447    // The layer's FBO is already bound when we reach this stage
1448    if (!layer->getStencilRenderBuffer()) {
1449        // GL_QCOM_tiled_rendering doesn't like it if a renderbuffer
1450        // is attached after we initiated tiling. We must turn it off,
1451        // attach the new render buffer then turn tiling back on
1452        endTiling();
1453
1454        RenderBuffer* buffer = mCaches.renderBufferCache.get(
1455                Stencil::getSmallestStencilFormat(), layer->getWidth(), layer->getHeight());
1456        layer->setStencilRenderBuffer(buffer);
1457
1458        startTiling(layer->clipRect, layer->layer.getHeight());
1459    }
1460}
1461
1462void OpenGLRenderer::setStencilFromClip() {
1463    if (!mCaches.debugOverdraw) {
1464        if (!mSnapshot->clipRegion->isEmpty()) {
1465            // NOTE: The order here is important, we must set dirtyClip to false
1466            //       before any draw call to avoid calling back into this method
1467            mDirtyClip = false;
1468
1469            ensureStencilBuffer();
1470
1471            mCaches.stencil.enableWrite();
1472
1473            // Clear the stencil but first make sure we restrict drawing
1474            // to the region's bounds
1475            bool resetScissor = mCaches.enableScissor();
1476            if (resetScissor) {
1477                // The scissor was not set so we now need to update it
1478                setScissorFromClip();
1479            }
1480            mCaches.stencil.clear();
1481            if (resetScissor) mCaches.disableScissor();
1482
1483            // NOTE: We could use the region contour path to generate a smaller mesh
1484            //       Since we are using the stencil we could use the red book path
1485            //       drawing technique. It might increase bandwidth usage though.
1486
1487            // The last parameter is important: we are not drawing in the color buffer
1488            // so we don't want to dirty the current layer, if any
1489            drawRegionRects(*mSnapshot->clipRegion, 0xff000000, SkXfermode::kSrc_Mode, false);
1490
1491            mCaches.stencil.enableTest();
1492
1493            // Draw the region used to generate the stencil if the appropriate debug
1494            // mode is enabled
1495            if (mCaches.debugStencilClip == Caches::kStencilShowRegion) {
1496                drawRegionRects(*mSnapshot->clipRegion, 0x7f0000ff, SkXfermode::kSrcOver_Mode);
1497            }
1498        } else {
1499            mCaches.stencil.disable();
1500        }
1501    }
1502}
1503
1504const Rect& OpenGLRenderer::getClipBounds() {
1505    return mSnapshot->getLocalClip();
1506}
1507
1508bool OpenGLRenderer::quickRejectNoScissor(float left, float top, float right, float bottom) {
1509    if (mSnapshot->isIgnored()) {
1510        return true;
1511    }
1512
1513    Rect r(left, top, right, bottom);
1514    currentTransform().mapRect(r);
1515    r.snapToPixelBoundaries();
1516
1517    Rect clipRect(*mSnapshot->clipRect);
1518    clipRect.snapToPixelBoundaries();
1519
1520    return !clipRect.intersects(r);
1521}
1522
1523bool OpenGLRenderer::quickRejectNoScissor(float left, float top, float right, float bottom,
1524        Rect& transformed, Rect& clip) {
1525    if (mSnapshot->isIgnored()) {
1526        return true;
1527    }
1528
1529    transformed.set(left, top, right, bottom);
1530    currentTransform().mapRect(transformed);
1531    transformed.snapToPixelBoundaries();
1532
1533    clip.set(*mSnapshot->clipRect);
1534    clip.snapToPixelBoundaries();
1535
1536    return !clip.intersects(transformed);
1537}
1538
1539bool OpenGLRenderer::quickRejectPreStroke(float left, float top, float right, float bottom,
1540        SkPaint* paint) {
1541    if (paint->getStyle() != SkPaint::kFill_Style) {
1542        float outset = paint->getStrokeWidth() * 0.5f;
1543        return quickReject(left - outset, top - outset, right + outset, bottom + outset);
1544    } else {
1545        return quickReject(left, top, right, bottom);
1546    }
1547}
1548
1549bool OpenGLRenderer::quickReject(float left, float top, float right, float bottom) {
1550    if (mSnapshot->isIgnored() || bottom <= top || right <= left) {
1551        return true;
1552    }
1553
1554    Rect r(left, top, right, bottom);
1555    currentTransform().mapRect(r);
1556    r.snapToPixelBoundaries();
1557
1558    Rect clipRect(*mSnapshot->clipRect);
1559    clipRect.snapToPixelBoundaries();
1560
1561    bool rejected = !clipRect.intersects(r);
1562    if (!isDeferred() && !rejected) {
1563        mCaches.setScissorEnabled(mScissorOptimizationDisabled || !clipRect.contains(r));
1564    }
1565
1566    return rejected;
1567}
1568
1569void OpenGLRenderer::debugClip() {
1570#if DEBUG_CLIP_REGIONS
1571    if (!isDeferred() && !mSnapshot->clipRegion->isEmpty()) {
1572        drawRegionRects(*mSnapshot->clipRegion, 0x7f00ff00, SkXfermode::kSrcOver_Mode);
1573    }
1574#endif
1575}
1576
1577bool OpenGLRenderer::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {
1578    if (CC_LIKELY(currentTransform().rectToRect())) {
1579        bool clipped = mSnapshot->clip(left, top, right, bottom, op);
1580        if (clipped) {
1581            dirtyClip();
1582        }
1583        return !mSnapshot->clipRect->isEmpty();
1584    }
1585
1586    SkPath path;
1587    path.addRect(left, top, right, bottom);
1588
1589    return clipPath(&path, op);
1590}
1591
1592bool OpenGLRenderer::clipPath(SkPath* path, SkRegion::Op op) {
1593    SkMatrix transform;
1594    currentTransform().copyTo(transform);
1595
1596    SkPath transformed;
1597    path->transform(transform, &transformed);
1598
1599    SkRegion clip;
1600    if (!mSnapshot->clipRegion->isEmpty()) {
1601        clip.setRegion(*mSnapshot->clipRegion);
1602    } else {
1603        Rect* bounds = mSnapshot->clipRect;
1604        clip.setRect(bounds->left, bounds->top, bounds->right, bounds->bottom);
1605    }
1606
1607    SkRegion region;
1608    region.setPath(transformed, clip);
1609
1610    bool clipped = mSnapshot->clipRegionTransformed(region, op);
1611    if (clipped) {
1612        dirtyClip();
1613    }
1614    return !mSnapshot->clipRect->isEmpty();
1615}
1616
1617bool OpenGLRenderer::clipRegion(SkRegion* region, SkRegion::Op op) {
1618    bool clipped = mSnapshot->clipRegionTransformed(*region, op);
1619    if (clipped) {
1620        dirtyClip();
1621    }
1622    return !mSnapshot->clipRect->isEmpty();
1623}
1624
1625Rect* OpenGLRenderer::getClipRect() {
1626    return mSnapshot->clipRect;
1627}
1628
1629///////////////////////////////////////////////////////////////////////////////
1630// Drawing commands
1631///////////////////////////////////////////////////////////////////////////////
1632
1633void OpenGLRenderer::setupDraw(bool clear) {
1634    // TODO: It would be best if we could do this before quickReject()
1635    //       changes the scissor test state
1636    if (clear) clearLayerRegions();
1637    // Make sure setScissor & setStencil happen at the beginning of
1638    // this method
1639    if (mDirtyClip) {
1640        if (mCaches.scissorEnabled) {
1641            setScissorFromClip();
1642        }
1643        setStencilFromClip();
1644    }
1645
1646    mDescription.reset();
1647
1648    mSetShaderColor = false;
1649    mColorSet = false;
1650    mColorA = mColorR = mColorG = mColorB = 0.0f;
1651    mTextureUnit = 0;
1652    mTrackDirtyRegions = true;
1653
1654    // Enable debug highlight when what we're about to draw is tested against
1655    // the stencil buffer and if stencil highlight debugging is on
1656    mDescription.hasDebugHighlight = !mCaches.debugOverdraw &&
1657            mCaches.debugStencilClip == Caches::kStencilShowHighlight &&
1658            mCaches.stencil.isTestEnabled();
1659}
1660
1661void OpenGLRenderer::setupDrawWithTexture(bool isAlpha8) {
1662    mDescription.hasTexture = true;
1663    mDescription.hasAlpha8Texture = isAlpha8;
1664}
1665
1666void OpenGLRenderer::setupDrawWithTextureAndColor(bool isAlpha8) {
1667    mDescription.hasTexture = true;
1668    mDescription.hasColors = true;
1669    mDescription.hasAlpha8Texture = isAlpha8;
1670}
1671
1672void OpenGLRenderer::setupDrawWithExternalTexture() {
1673    mDescription.hasExternalTexture = true;
1674}
1675
1676void OpenGLRenderer::setupDrawNoTexture() {
1677    mCaches.disableTexCoordsVertexArray();
1678}
1679
1680void OpenGLRenderer::setupDrawAA() {
1681    mDescription.isAA = true;
1682}
1683
1684void OpenGLRenderer::setupDrawPoint(float pointSize) {
1685    mDescription.isPoint = true;
1686    mDescription.pointSize = pointSize;
1687}
1688
1689void OpenGLRenderer::setupDrawColor(int color, int alpha) {
1690    mColorA = alpha / 255.0f;
1691    mColorR = mColorA * ((color >> 16) & 0xFF) / 255.0f;
1692    mColorG = mColorA * ((color >>  8) & 0xFF) / 255.0f;
1693    mColorB = mColorA * ((color      ) & 0xFF) / 255.0f;
1694    mColorSet = true;
1695    mSetShaderColor = mDescription.setColor(mColorR, mColorG, mColorB, mColorA);
1696}
1697
1698void OpenGLRenderer::setupDrawAlpha8Color(int color, int alpha) {
1699    mColorA = alpha / 255.0f;
1700    mColorR = mColorA * ((color >> 16) & 0xFF) / 255.0f;
1701    mColorG = mColorA * ((color >>  8) & 0xFF) / 255.0f;
1702    mColorB = mColorA * ((color      ) & 0xFF) / 255.0f;
1703    mColorSet = true;
1704    mSetShaderColor = mDescription.setAlpha8Color(mColorR, mColorG, mColorB, mColorA);
1705}
1706
1707void OpenGLRenderer::setupDrawTextGamma(const SkPaint* paint) {
1708    mCaches.fontRenderer->describe(mDescription, paint);
1709}
1710
1711void OpenGLRenderer::setupDrawColor(float r, float g, float b, float a) {
1712    mColorA = a;
1713    mColorR = r;
1714    mColorG = g;
1715    mColorB = b;
1716    mColorSet = true;
1717    mSetShaderColor = mDescription.setColor(r, g, b, a);
1718}
1719
1720void OpenGLRenderer::setupDrawShader() {
1721    if (mDrawModifiers.mShader) {
1722        mDrawModifiers.mShader->describe(mDescription, mExtensions);
1723    }
1724}
1725
1726void OpenGLRenderer::setupDrawColorFilter() {
1727    if (mDrawModifiers.mColorFilter) {
1728        mDrawModifiers.mColorFilter->describe(mDescription, mExtensions);
1729    }
1730}
1731
1732void OpenGLRenderer::accountForClear(SkXfermode::Mode mode) {
1733    if (mColorSet && mode == SkXfermode::kClear_Mode) {
1734        mColorA = 1.0f;
1735        mColorR = mColorG = mColorB = 0.0f;
1736        mSetShaderColor = mDescription.modulate = true;
1737    }
1738}
1739
1740void OpenGLRenderer::setupDrawBlending(SkXfermode::Mode mode, bool swapSrcDst) {
1741    // When the blending mode is kClear_Mode, we need to use a modulate color
1742    // argb=1,0,0,0
1743    accountForClear(mode);
1744    bool blend = (mColorSet && mColorA < 1.0f) ||
1745            (mDrawModifiers.mShader && mDrawModifiers.mShader->blend());
1746    chooseBlending(blend, mode, mDescription, swapSrcDst);
1747}
1748
1749void OpenGLRenderer::setupDrawBlending(bool blend, SkXfermode::Mode mode, bool swapSrcDst) {
1750    // When the blending mode is kClear_Mode, we need to use a modulate color
1751    // argb=1,0,0,0
1752    accountForClear(mode);
1753    blend |= (mColorSet && mColorA < 1.0f) ||
1754            (mDrawModifiers.mShader && mDrawModifiers.mShader->blend()) ||
1755            (mDrawModifiers.mColorFilter && mDrawModifiers.mColorFilter->blend());
1756    chooseBlending(blend, mode, mDescription, swapSrcDst);
1757}
1758
1759void OpenGLRenderer::setupDrawProgram() {
1760    useProgram(mCaches.programCache.get(mDescription));
1761}
1762
1763void OpenGLRenderer::setupDrawDirtyRegionsDisabled() {
1764    mTrackDirtyRegions = false;
1765}
1766
1767void OpenGLRenderer::setupDrawModelViewTranslate(float left, float top, float right, float bottom,
1768        bool ignoreTransform) {
1769    mModelView.loadTranslate(left, top, 0.0f);
1770    if (!ignoreTransform) {
1771        mCaches.currentProgram->set(mOrthoMatrix, mModelView, currentTransform());
1772        if (mTrackDirtyRegions) dirtyLayer(left, top, right, bottom, currentTransform());
1773    } else {
1774        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mat4::identity());
1775        if (mTrackDirtyRegions) dirtyLayer(left, top, right, bottom);
1776    }
1777}
1778
1779void OpenGLRenderer::setupDrawModelViewIdentity(bool offset) {
1780    mCaches.currentProgram->set(mOrthoMatrix, mat4::identity(), currentTransform(), offset);
1781}
1782
1783void OpenGLRenderer::setupDrawModelView(float left, float top, float right, float bottom,
1784        bool ignoreTransform, bool ignoreModelView) {
1785    if (!ignoreModelView) {
1786        mModelView.loadTranslate(left, top, 0.0f);
1787        mModelView.scale(right - left, bottom - top, 1.0f);
1788    } else {
1789        mModelView.loadIdentity();
1790    }
1791    bool dirty = right - left > 0.0f && bottom - top > 0.0f;
1792    if (!ignoreTransform) {
1793        mCaches.currentProgram->set(mOrthoMatrix, mModelView, currentTransform());
1794        if (mTrackDirtyRegions && dirty) {
1795            dirtyLayer(left, top, right, bottom, currentTransform());
1796        }
1797    } else {
1798        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mat4::identity());
1799        if (mTrackDirtyRegions && dirty) dirtyLayer(left, top, right, bottom);
1800    }
1801}
1802
1803void OpenGLRenderer::setupDrawPointUniforms() {
1804    int slot = mCaches.currentProgram->getUniform("pointSize");
1805    glUniform1f(slot, mDescription.pointSize);
1806}
1807
1808void OpenGLRenderer::setupDrawColorUniforms() {
1809    if ((mColorSet && !mDrawModifiers.mShader) || (mDrawModifiers.mShader && mSetShaderColor)) {
1810        mCaches.currentProgram->setColor(mColorR, mColorG, mColorB, mColorA);
1811    }
1812}
1813
1814void OpenGLRenderer::setupDrawPureColorUniforms() {
1815    if (mSetShaderColor) {
1816        mCaches.currentProgram->setColor(mColorR, mColorG, mColorB, mColorA);
1817    }
1818}
1819
1820void OpenGLRenderer::setupDrawShaderUniforms(bool ignoreTransform) {
1821    if (mDrawModifiers.mShader) {
1822        if (ignoreTransform) {
1823            mModelView.loadInverse(currentTransform());
1824        }
1825        mDrawModifiers.mShader->setupProgram(mCaches.currentProgram,
1826                mModelView, *mSnapshot, &mTextureUnit);
1827    }
1828}
1829
1830void OpenGLRenderer::setupDrawShaderIdentityUniforms() {
1831    if (mDrawModifiers.mShader) {
1832        mDrawModifiers.mShader->setupProgram(mCaches.currentProgram,
1833                mat4::identity(), *mSnapshot, &mTextureUnit);
1834    }
1835}
1836
1837void OpenGLRenderer::setupDrawColorFilterUniforms() {
1838    if (mDrawModifiers.mColorFilter) {
1839        mDrawModifiers.mColorFilter->setupProgram(mCaches.currentProgram);
1840    }
1841}
1842
1843void OpenGLRenderer::setupDrawTextGammaUniforms() {
1844    mCaches.fontRenderer->setupProgram(mDescription, mCaches.currentProgram);
1845}
1846
1847void OpenGLRenderer::setupDrawSimpleMesh() {
1848    bool force = mCaches.bindMeshBuffer();
1849    mCaches.bindPositionVertexPointer(force, 0);
1850    mCaches.unbindIndicesBuffer();
1851}
1852
1853void OpenGLRenderer::setupDrawTexture(GLuint texture) {
1854    if (texture) bindTexture(texture);
1855    mTextureUnit++;
1856    mCaches.enableTexCoordsVertexArray();
1857}
1858
1859void OpenGLRenderer::setupDrawExternalTexture(GLuint texture) {
1860    bindExternalTexture(texture);
1861    mTextureUnit++;
1862    mCaches.enableTexCoordsVertexArray();
1863}
1864
1865void OpenGLRenderer::setupDrawTextureTransform() {
1866    mDescription.hasTextureTransform = true;
1867}
1868
1869void OpenGLRenderer::setupDrawTextureTransformUniforms(mat4& transform) {
1870    glUniformMatrix4fv(mCaches.currentProgram->getUniform("mainTextureTransform"), 1,
1871            GL_FALSE, &transform.data[0]);
1872}
1873
1874void OpenGLRenderer::setupDrawMesh(GLvoid* vertices, GLvoid* texCoords, GLuint vbo) {
1875    bool force = false;
1876    if (!vertices) {
1877        force = mCaches.bindMeshBuffer(vbo == 0 ? mCaches.meshBuffer : vbo);
1878    } else {
1879        force = mCaches.unbindMeshBuffer();
1880    }
1881
1882    mCaches.bindPositionVertexPointer(force, vertices);
1883    if (mCaches.currentProgram->texCoords >= 0) {
1884        mCaches.bindTexCoordsVertexPointer(force, texCoords);
1885    }
1886
1887    mCaches.unbindIndicesBuffer();
1888}
1889
1890void OpenGLRenderer::setupDrawMesh(GLvoid* vertices, GLvoid* texCoords, GLvoid* colors) {
1891    bool force = mCaches.unbindMeshBuffer();
1892    GLsizei stride = sizeof(ColorTextureVertex);
1893
1894    mCaches.bindPositionVertexPointer(force, vertices, stride);
1895    if (mCaches.currentProgram->texCoords >= 0) {
1896        mCaches.bindTexCoordsVertexPointer(force, texCoords, stride);
1897    }
1898    int slot = mCaches.currentProgram->getAttrib("colors");
1899    if (slot >= 0) {
1900        glEnableVertexAttribArray(slot);
1901        glVertexAttribPointer(slot, 4, GL_FLOAT, GL_FALSE, stride, colors);
1902    }
1903
1904    mCaches.unbindIndicesBuffer();
1905}
1906
1907void OpenGLRenderer::setupDrawMeshIndices(GLvoid* vertices, GLvoid* texCoords) {
1908    bool force = mCaches.unbindMeshBuffer();
1909    mCaches.bindPositionVertexPointer(force, vertices);
1910    if (mCaches.currentProgram->texCoords >= 0) {
1911        mCaches.bindTexCoordsVertexPointer(force, texCoords);
1912    }
1913}
1914
1915void OpenGLRenderer::setupDrawVertices(GLvoid* vertices) {
1916    bool force = mCaches.unbindMeshBuffer();
1917    mCaches.bindPositionVertexPointer(force, vertices, gVertexStride);
1918    mCaches.unbindIndicesBuffer();
1919}
1920
1921void OpenGLRenderer::finishDrawTexture() {
1922}
1923
1924///////////////////////////////////////////////////////////////////////////////
1925// Drawing
1926///////////////////////////////////////////////////////////////////////////////
1927
1928status_t OpenGLRenderer::drawDisplayList(DisplayList* displayList, Rect& dirty,
1929        int32_t replayFlags) {
1930    status_t status;
1931    // All the usual checks and setup operations (quickReject, setupDraw, etc.)
1932    // will be performed by the display list itself
1933    if (displayList && displayList->isRenderable()) {
1934        if (CC_UNLIKELY(mCaches.drawDeferDisabled)) {
1935            status = startFrame();
1936            ReplayStateStruct replayStruct(*this, dirty, replayFlags);
1937            displayList->replay(replayStruct, 0);
1938            return status | replayStruct.mDrawGlStatus;
1939        }
1940
1941        DeferredDisplayList deferredList;
1942        DeferStateStruct deferStruct(deferredList, *this, replayFlags);
1943        displayList->defer(deferStruct, 0);
1944
1945        flushLayers();
1946        status = startFrame();
1947
1948        return status | deferredList.flush(*this, dirty);
1949    }
1950
1951    return DrawGlInfo::kStatusDone;
1952}
1953
1954void OpenGLRenderer::outputDisplayList(DisplayList* displayList) {
1955    if (displayList) {
1956        displayList->output(1);
1957    }
1958}
1959
1960void OpenGLRenderer::drawAlphaBitmap(Texture* texture, float left, float top, SkPaint* paint) {
1961    int alpha;
1962    SkXfermode::Mode mode;
1963    getAlphaAndMode(paint, &alpha, &mode);
1964
1965    int color = paint != NULL ? paint->getColor() : 0;
1966
1967    float x = left;
1968    float y = top;
1969
1970    texture->setWrap(GL_CLAMP_TO_EDGE, true);
1971
1972    bool ignoreTransform = false;
1973    if (currentTransform().isPureTranslate()) {
1974        x = (int) floorf(left + currentTransform().getTranslateX() + 0.5f);
1975        y = (int) floorf(top + currentTransform().getTranslateY() + 0.5f);
1976        ignoreTransform = true;
1977
1978        texture->setFilter(GL_NEAREST, true);
1979    } else {
1980        texture->setFilter(FILTER(paint), true);
1981    }
1982
1983    drawAlpha8TextureMesh(x, y, x + texture->width, y + texture->height, texture->id,
1984            paint != NULL, color, alpha, mode, (GLvoid*) NULL,
1985            (GLvoid*) gMeshTextureOffset, GL_TRIANGLE_STRIP, gMeshCount, ignoreTransform);
1986}
1987
1988status_t OpenGLRenderer::drawBitmaps(SkBitmap* bitmap, int bitmapCount, TextureVertex* vertices,
1989        const Rect& bounds, SkPaint* paint) {
1990
1991    // merged draw operations don't need scissor, but clip should still be valid
1992    mCaches.setScissorEnabled(mScissorOptimizationDisabled);
1993
1994    mCaches.activeTexture(0);
1995    Texture* texture = mCaches.textureCache.get(bitmap);
1996    if (!texture) return DrawGlInfo::kStatusDone;
1997    const AutoTexture autoCleanup(texture);
1998
1999    int alpha;
2000    SkXfermode::Mode mode;
2001    getAlphaAndMode(paint, &alpha, &mode);
2002
2003    texture->setWrap(GL_CLAMP_TO_EDGE, true);
2004    texture->setFilter(GL_NEAREST, true); // merged ops are always pure-translation for now
2005
2006    const float x = (int) floorf(bounds.left + 0.5f);
2007    const float y = (int) floorf(bounds.top + 0.5f);
2008    if (CC_UNLIKELY(bitmap->getConfig() == SkBitmap::kA8_Config)) {
2009        int color = paint != NULL ? paint->getColor() : 0;
2010        drawAlpha8TextureMesh(x, y, x + bounds.getWidth(), y + bounds.getHeight(),
2011                texture->id, paint != NULL, color, alpha, mode,
2012                &vertices[0].position[0], &vertices[0].texture[0],
2013                GL_TRIANGLES, bitmapCount * 6, true, true);
2014    } else {
2015        drawTextureMesh(x, y, x + bounds.getWidth(), y + bounds.getHeight(),
2016                texture->id, alpha / 255.0f, mode, texture->blend,
2017                &vertices[0].position[0], &vertices[0].texture[0],
2018                GL_TRIANGLES, bitmapCount * 6, false, true, 0, true);
2019    }
2020
2021    return DrawGlInfo::kStatusDrew;
2022}
2023
2024status_t OpenGLRenderer::drawBitmap(SkBitmap* bitmap, float left, float top, SkPaint* paint) {
2025    const float right = left + bitmap->width();
2026    const float bottom = top + bitmap->height();
2027
2028    if (quickReject(left, top, right, bottom)) {
2029        return DrawGlInfo::kStatusDone;
2030    }
2031
2032    mCaches.activeTexture(0);
2033    Texture* texture = mCaches.textureCache.get(bitmap);
2034    if (!texture) return DrawGlInfo::kStatusDone;
2035    const AutoTexture autoCleanup(texture);
2036
2037    if (CC_UNLIKELY(bitmap->getConfig() == SkBitmap::kA8_Config)) {
2038        drawAlphaBitmap(texture, left, top, paint);
2039    } else {
2040        drawTextureRect(left, top, right, bottom, texture, paint);
2041    }
2042
2043    return DrawGlInfo::kStatusDrew;
2044}
2045
2046status_t OpenGLRenderer::drawBitmap(SkBitmap* bitmap, SkMatrix* matrix, SkPaint* paint) {
2047    Rect r(0.0f, 0.0f, bitmap->width(), bitmap->height());
2048    const mat4 transform(*matrix);
2049    transform.mapRect(r);
2050
2051    if (quickReject(r.left, r.top, r.right, r.bottom)) {
2052        return DrawGlInfo::kStatusDone;
2053    }
2054
2055    mCaches.activeTexture(0);
2056    Texture* texture = mCaches.textureCache.get(bitmap);
2057    if (!texture) return DrawGlInfo::kStatusDone;
2058    const AutoTexture autoCleanup(texture);
2059
2060    // This could be done in a cheaper way, all we need is pass the matrix
2061    // to the vertex shader. The save/restore is a bit overkill.
2062    save(SkCanvas::kMatrix_SaveFlag);
2063    concatMatrix(matrix);
2064    if (CC_UNLIKELY(bitmap->getConfig() == SkBitmap::kA8_Config)) {
2065        drawAlphaBitmap(texture, 0.0f, 0.0f, paint);
2066    } else {
2067        drawTextureRect(0.0f, 0.0f, bitmap->width(), bitmap->height(), texture, paint);
2068    }
2069    restore();
2070
2071    return DrawGlInfo::kStatusDrew;
2072}
2073
2074status_t OpenGLRenderer::drawBitmapData(SkBitmap* bitmap, float left, float top, SkPaint* paint) {
2075    const float right = left + bitmap->width();
2076    const float bottom = top + bitmap->height();
2077
2078    if (quickReject(left, top, right, bottom)) {
2079        return DrawGlInfo::kStatusDone;
2080    }
2081
2082    mCaches.activeTexture(0);
2083    Texture* texture = mCaches.textureCache.getTransient(bitmap);
2084    const AutoTexture autoCleanup(texture);
2085
2086    if (CC_UNLIKELY(bitmap->getConfig() == SkBitmap::kA8_Config)) {
2087        drawAlphaBitmap(texture, left, top, paint);
2088    } else {
2089        drawTextureRect(left, top, right, bottom, texture, paint);
2090    }
2091
2092    return DrawGlInfo::kStatusDrew;
2093}
2094
2095status_t OpenGLRenderer::drawBitmapMesh(SkBitmap* bitmap, int meshWidth, int meshHeight,
2096        float* vertices, int* colors, SkPaint* paint) {
2097    if (!vertices || mSnapshot->isIgnored()) {
2098        return DrawGlInfo::kStatusDone;
2099    }
2100
2101    float left = FLT_MAX;
2102    float top = FLT_MAX;
2103    float right = FLT_MIN;
2104    float bottom = FLT_MIN;
2105
2106    const uint32_t count = meshWidth * meshHeight * 6;
2107
2108    ColorTextureVertex mesh[count];
2109    ColorTextureVertex* vertex = mesh;
2110
2111    bool cleanupColors = false;
2112    if (!colors) {
2113        uint32_t colorsCount = (meshWidth + 1) * (meshHeight + 1);
2114        colors = new int[colorsCount];
2115        memset(colors, 0xff, colorsCount * sizeof(int));
2116        cleanupColors = true;
2117    }
2118
2119    for (int32_t y = 0; y < meshHeight; y++) {
2120        for (int32_t x = 0; x < meshWidth; x++) {
2121            uint32_t i = (y * (meshWidth + 1) + x) * 2;
2122
2123            float u1 = float(x) / meshWidth;
2124            float u2 = float(x + 1) / meshWidth;
2125            float v1 = float(y) / meshHeight;
2126            float v2 = float(y + 1) / meshHeight;
2127
2128            int ax = i + (meshWidth + 1) * 2;
2129            int ay = ax + 1;
2130            int bx = i;
2131            int by = bx + 1;
2132            int cx = i + 2;
2133            int cy = cx + 1;
2134            int dx = i + (meshWidth + 1) * 2 + 2;
2135            int dy = dx + 1;
2136
2137            ColorTextureVertex::set(vertex++, vertices[dx], vertices[dy], u2, v2, colors[dx / 2]);
2138            ColorTextureVertex::set(vertex++, vertices[ax], vertices[ay], u1, v2, colors[ax / 2]);
2139            ColorTextureVertex::set(vertex++, vertices[bx], vertices[by], u1, v1, colors[bx / 2]);
2140
2141            ColorTextureVertex::set(vertex++, vertices[dx], vertices[dy], u2, v2, colors[dx / 2]);
2142            ColorTextureVertex::set(vertex++, vertices[bx], vertices[by], u1, v1, colors[bx / 2]);
2143            ColorTextureVertex::set(vertex++, vertices[cx], vertices[cy], u2, v1, colors[cx / 2]);
2144
2145            left = fminf(left, fminf(vertices[ax], fminf(vertices[bx], vertices[cx])));
2146            top = fminf(top, fminf(vertices[ay], fminf(vertices[by], vertices[cy])));
2147            right = fmaxf(right, fmaxf(vertices[ax], fmaxf(vertices[bx], vertices[cx])));
2148            bottom = fmaxf(bottom, fmaxf(vertices[ay], fmaxf(vertices[by], vertices[cy])));
2149        }
2150    }
2151
2152    if (quickReject(left, top, right, bottom)) {
2153        if (cleanupColors) delete[] colors;
2154        return DrawGlInfo::kStatusDone;
2155    }
2156
2157    mCaches.activeTexture(0);
2158    Texture* texture = mCaches.textureCache.get(bitmap);
2159    if (!texture) {
2160        if (cleanupColors) delete[] colors;
2161        return DrawGlInfo::kStatusDone;
2162    }
2163    const AutoTexture autoCleanup(texture);
2164
2165    texture->setWrap(GL_CLAMP_TO_EDGE, true);
2166    texture->setFilter(FILTER(paint), true);
2167
2168    int alpha;
2169    SkXfermode::Mode mode;
2170    getAlphaAndMode(paint, &alpha, &mode);
2171
2172    float a = alpha / 255.0f;
2173
2174    if (hasLayer()) {
2175        dirtyLayer(left, top, right, bottom, currentTransform());
2176    }
2177
2178    setupDraw();
2179    setupDrawWithTextureAndColor();
2180    setupDrawColor(a, a, a, a);
2181    setupDrawColorFilter();
2182    setupDrawBlending(true, mode, false);
2183    setupDrawProgram();
2184    setupDrawDirtyRegionsDisabled();
2185    setupDrawModelView(0.0f, 0.0f, 1.0f, 1.0f, false);
2186    setupDrawTexture(texture->id);
2187    setupDrawPureColorUniforms();
2188    setupDrawColorFilterUniforms();
2189    setupDrawMesh(&mesh[0].position[0], &mesh[0].texture[0], &mesh[0].color[0]);
2190
2191    glDrawArrays(GL_TRIANGLES, 0, count);
2192
2193    finishDrawTexture();
2194
2195    int slot = mCaches.currentProgram->getAttrib("colors");
2196    if (slot >= 0) {
2197        glDisableVertexAttribArray(slot);
2198    }
2199
2200    if (cleanupColors) delete[] colors;
2201
2202    return DrawGlInfo::kStatusDrew;
2203}
2204
2205status_t OpenGLRenderer::drawBitmap(SkBitmap* bitmap,
2206         float srcLeft, float srcTop, float srcRight, float srcBottom,
2207         float dstLeft, float dstTop, float dstRight, float dstBottom,
2208         SkPaint* paint) {
2209    if (quickReject(dstLeft, dstTop, dstRight, dstBottom)) {
2210        return DrawGlInfo::kStatusDone;
2211    }
2212
2213    mCaches.activeTexture(0);
2214    Texture* texture = mCaches.textureCache.get(bitmap);
2215    if (!texture) return DrawGlInfo::kStatusDone;
2216    const AutoTexture autoCleanup(texture);
2217
2218    const float width = texture->width;
2219    const float height = texture->height;
2220
2221    const float u1 = fmax(0.0f, srcLeft / width);
2222    const float v1 = fmax(0.0f, srcTop / height);
2223    const float u2 = fmin(1.0f, srcRight / width);
2224    const float v2 = fmin(1.0f, srcBottom / height);
2225
2226    mCaches.unbindMeshBuffer();
2227    resetDrawTextureTexCoords(u1, v1, u2, v2);
2228
2229    int alpha;
2230    SkXfermode::Mode mode;
2231    getAlphaAndMode(paint, &alpha, &mode);
2232
2233    texture->setWrap(GL_CLAMP_TO_EDGE, true);
2234
2235    float scaleX = (dstRight - dstLeft) / (srcRight - srcLeft);
2236    float scaleY = (dstBottom - dstTop) / (srcBottom - srcTop);
2237
2238    bool scaled = scaleX != 1.0f || scaleY != 1.0f;
2239    // Apply a scale transform on the canvas only when a shader is in use
2240    // Skia handles the ratio between the dst and src rects as a scale factor
2241    // when a shader is set
2242    bool useScaleTransform = mDrawModifiers.mShader && scaled;
2243    bool ignoreTransform = false;
2244
2245    if (CC_LIKELY(currentTransform().isPureTranslate() && !useScaleTransform)) {
2246        float x = (int) floorf(dstLeft + currentTransform().getTranslateX() + 0.5f);
2247        float y = (int) floorf(dstTop + currentTransform().getTranslateY() + 0.5f);
2248
2249        dstRight = x + (dstRight - dstLeft);
2250        dstBottom = y + (dstBottom - dstTop);
2251
2252        dstLeft = x;
2253        dstTop = y;
2254
2255        texture->setFilter(scaled ? FILTER(paint) : GL_NEAREST, true);
2256        ignoreTransform = true;
2257    } else {
2258        texture->setFilter(FILTER(paint), true);
2259    }
2260
2261    if (CC_UNLIKELY(useScaleTransform)) {
2262        save(SkCanvas::kMatrix_SaveFlag);
2263        translate(dstLeft, dstTop);
2264        scale(scaleX, scaleY);
2265
2266        dstLeft = 0.0f;
2267        dstTop = 0.0f;
2268
2269        dstRight = srcRight - srcLeft;
2270        dstBottom = srcBottom - srcTop;
2271    }
2272
2273    if (CC_UNLIKELY(bitmap->getConfig() == SkBitmap::kA8_Config)) {
2274        int color = paint ? paint->getColor() : 0;
2275        drawAlpha8TextureMesh(dstLeft, dstTop, dstRight, dstBottom,
2276                texture->id, paint != NULL, color, alpha, mode,
2277                &mMeshVertices[0].position[0], &mMeshVertices[0].texture[0],
2278                GL_TRIANGLE_STRIP, gMeshCount, ignoreTransform);
2279    } else {
2280        drawTextureMesh(dstLeft, dstTop, dstRight, dstBottom,
2281                texture->id, alpha / 255.0f, mode, texture->blend,
2282                &mMeshVertices[0].position[0], &mMeshVertices[0].texture[0],
2283                GL_TRIANGLE_STRIP, gMeshCount, false, ignoreTransform);
2284    }
2285
2286    if (CC_UNLIKELY(useScaleTransform)) {
2287        restore();
2288    }
2289
2290    resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
2291
2292    return DrawGlInfo::kStatusDrew;
2293}
2294
2295status_t OpenGLRenderer::drawPatch(SkBitmap* bitmap, const int32_t* xDivs, const int32_t* yDivs,
2296        const uint32_t* colors, uint32_t width, uint32_t height, int8_t numColors,
2297        float left, float top, float right, float bottom, SkPaint* paint) {
2298    int alpha;
2299    SkXfermode::Mode mode;
2300    getAlphaAndMode(paint, &alpha, &mode);
2301
2302    return drawPatch(bitmap, xDivs, yDivs, colors, width, height, numColors,
2303            left, top, right, bottom, alpha, mode);
2304}
2305
2306status_t OpenGLRenderer::drawPatch(SkBitmap* bitmap, const int32_t* xDivs, const int32_t* yDivs,
2307        const uint32_t* colors, uint32_t width, uint32_t height, int8_t numColors,
2308        float left, float top, float right, float bottom, int alpha, SkXfermode::Mode mode) {
2309    if (quickReject(left, top, right, bottom)) {
2310        return DrawGlInfo::kStatusDone;
2311    }
2312
2313    alpha *= mSnapshot->alpha;
2314
2315    const Patch* mesh = mCaches.patchCache.get(bitmap->width(), bitmap->height(),
2316            right - left, bottom - top, xDivs, yDivs, colors, width, height, numColors);
2317
2318    if (CC_LIKELY(mesh && mesh->verticesCount > 0)) {
2319        mCaches.activeTexture(0);
2320        Texture* texture = mCaches.textureCache.get(bitmap);
2321        if (!texture) return DrawGlInfo::kStatusDone;
2322        const AutoTexture autoCleanup(texture);
2323        texture->setWrap(GL_CLAMP_TO_EDGE, true);
2324        texture->setFilter(GL_LINEAR, true);
2325
2326        const bool pureTranslate = currentTransform().isPureTranslate();
2327        // Mark the current layer dirty where we are going to draw the patch
2328        if (hasLayer() && mesh->hasEmptyQuads) {
2329            const float offsetX = left + currentTransform().getTranslateX();
2330            const float offsetY = top + currentTransform().getTranslateY();
2331            const size_t count = mesh->quads.size();
2332            for (size_t i = 0; i < count; i++) {
2333                const Rect& bounds = mesh->quads.itemAt(i);
2334                if (CC_LIKELY(pureTranslate)) {
2335                    const float x = (int) floorf(bounds.left + offsetX + 0.5f);
2336                    const float y = (int) floorf(bounds.top + offsetY + 0.5f);
2337                    dirtyLayer(x, y, x + bounds.getWidth(), y + bounds.getHeight());
2338                } else {
2339                    dirtyLayer(left + bounds.left, top + bounds.top,
2340                            left + bounds.right, top + bounds.bottom, currentTransform());
2341                }
2342            }
2343        }
2344
2345        if (CC_LIKELY(pureTranslate)) {
2346            const float x = (int) floorf(left + currentTransform().getTranslateX() + 0.5f);
2347            const float y = (int) floorf(top + currentTransform().getTranslateY() + 0.5f);
2348
2349            drawTextureMesh(x, y, x + right - left, y + bottom - top, texture->id, alpha / 255.0f,
2350                    mode, texture->blend, (GLvoid*) 0, (GLvoid*) gMeshTextureOffset,
2351                    GL_TRIANGLES, mesh->verticesCount, false, true, mesh->meshBuffer,
2352                    true, !mesh->hasEmptyQuads);
2353        } else {
2354            drawTextureMesh(left, top, right, bottom, texture->id, alpha / 255.0f,
2355                    mode, texture->blend, (GLvoid*) 0, (GLvoid*) gMeshTextureOffset,
2356                    GL_TRIANGLES, mesh->verticesCount, false, false, mesh->meshBuffer,
2357                    true, !mesh->hasEmptyQuads);
2358        }
2359    }
2360
2361    return DrawGlInfo::kStatusDrew;
2362}
2363
2364status_t OpenGLRenderer::drawVertexBuffer(const VertexBuffer& vertexBuffer, SkPaint* paint,
2365        bool useOffset) {
2366    if (!vertexBuffer.getSize()) {
2367        // no vertices to draw
2368        return DrawGlInfo::kStatusDone;
2369    }
2370
2371    int color = paint->getColor();
2372    SkXfermode::Mode mode = getXfermode(paint->getXfermode());
2373    bool isAA = paint->isAntiAlias();
2374
2375    setupDraw();
2376    setupDrawNoTexture();
2377    if (isAA) setupDrawAA();
2378    setupDrawColor(color, ((color >> 24) & 0xFF) * mSnapshot->alpha);
2379    setupDrawColorFilter();
2380    setupDrawShader();
2381    setupDrawBlending(isAA, mode);
2382    setupDrawProgram();
2383    setupDrawModelViewIdentity(useOffset);
2384    setupDrawColorUniforms();
2385    setupDrawColorFilterUniforms();
2386    setupDrawShaderIdentityUniforms();
2387
2388    void* vertices = vertexBuffer.getBuffer();
2389    bool force = mCaches.unbindMeshBuffer();
2390    mCaches.bindPositionVertexPointer(true, vertices, isAA ? gAlphaVertexStride : gVertexStride);
2391    mCaches.resetTexCoordsVertexPointer();
2392    mCaches.unbindIndicesBuffer();
2393
2394    int alphaSlot = -1;
2395    if (isAA) {
2396        void* alphaCoords = ((GLbyte*) vertices) + gVertexAlphaOffset;
2397        alphaSlot = mCaches.currentProgram->getAttrib("vtxAlpha");
2398
2399        // TODO: avoid enable/disable in back to back uses of the alpha attribute
2400        glEnableVertexAttribArray(alphaSlot);
2401        glVertexAttribPointer(alphaSlot, 1, GL_FLOAT, GL_FALSE, gAlphaVertexStride, alphaCoords);
2402    }
2403
2404    glDrawArrays(GL_TRIANGLE_STRIP, 0, vertexBuffer.getSize());
2405
2406    if (isAA) {
2407        glDisableVertexAttribArray(alphaSlot);
2408    }
2409
2410    return DrawGlInfo::kStatusDrew;
2411}
2412
2413/**
2414 * Renders a convex path via tessellation. For AA paths, this function uses a similar approach to
2415 * that of AA lines in the drawLines() function.  We expand the convex path by a half pixel in
2416 * screen space in all directions. However, instead of using a fragment shader to compute the
2417 * translucency of the color from its position, we simply use a varying parameter to define how far
2418 * a given pixel is from the edge. For non-AA paths, the expansion and alpha varying are not used.
2419 *
2420 * Doesn't yet support joins, caps, or path effects.
2421 */
2422status_t OpenGLRenderer::drawConvexPath(const SkPath& path, SkPaint* paint) {
2423    VertexBuffer vertexBuffer;
2424    // TODO: try clipping large paths to viewport
2425    PathTessellator::tessellatePath(path, paint, mSnapshot->transform, vertexBuffer);
2426
2427    if (hasLayer()) {
2428        SkRect bounds = path.getBounds();
2429        PathTessellator::expandBoundsForStroke(bounds, paint, false);
2430        dirtyLayer(bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom, currentTransform());
2431    }
2432
2433    return drawVertexBuffer(vertexBuffer, paint);
2434}
2435
2436/**
2437 * We create tristrips for the lines much like shape stroke tessellation, using a per-vertex alpha
2438 * and additional geometry for defining an alpha slope perimeter.
2439 *
2440 * Using GL_LINES can be difficult because the rasterization rules for those lines produces some
2441 * unexpected results, and may vary between hardware devices. Previously we used a varying-base
2442 * in-shader alpha region, but found it to be taxing on some GPUs.
2443 *
2444 * TODO: try using a fixed input buffer for non-capped lines as in text rendering. this may reduce
2445 * memory transfer by removing need for degenerate vertices.
2446 */
2447status_t OpenGLRenderer::drawLines(float* points, int count, SkPaint* paint) {
2448    if (mSnapshot->isIgnored() || count < 4) return DrawGlInfo::kStatusDone;
2449
2450    count &= ~0x3; // round down to nearest four
2451
2452    VertexBuffer buffer;
2453    SkRect bounds;
2454    PathTessellator::tessellateLines(points, count, paint, mSnapshot->transform, bounds, buffer);
2455
2456    if (quickReject(bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom)) {
2457        return DrawGlInfo::kStatusDone;
2458    }
2459
2460    dirtyLayer(bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom, currentTransform());
2461
2462    bool useOffset = !paint->isAntiAlias();
2463    return drawVertexBuffer(buffer, paint, useOffset);
2464}
2465
2466status_t OpenGLRenderer::drawPoints(float* points, int count, SkPaint* paint) {
2467    if (mSnapshot->isIgnored()) return DrawGlInfo::kStatusDone;
2468
2469    // TODO: The paint's cap style defines whether the points are square or circular
2470    // TODO: Handle AA for round points
2471
2472    // A stroke width of 0 has a special meaning in Skia:
2473    // it draws an unscaled 1px point
2474    float strokeWidth = paint->getStrokeWidth();
2475    const bool isHairLine = paint->getStrokeWidth() == 0.0f;
2476    if (isHairLine) {
2477        // Now that we know it's hairline, we can set the effective width, to be used later
2478        strokeWidth = 1.0f;
2479    }
2480    const float halfWidth = strokeWidth / 2;
2481
2482    int alpha;
2483    SkXfermode::Mode mode;
2484    getAlphaAndMode(paint, &alpha, &mode);
2485
2486    int verticesCount = count >> 1;
2487    int generatedVerticesCount = 0;
2488
2489    TextureVertex pointsData[verticesCount];
2490    TextureVertex* vertex = &pointsData[0];
2491
2492    // TODO: We should optimize this method to not generate vertices for points
2493    // that lie outside of the clip.
2494    mCaches.enableScissor();
2495
2496    setupDraw();
2497    setupDrawNoTexture();
2498    setupDrawPoint(strokeWidth);
2499    setupDrawColor(paint->getColor(), alpha);
2500    setupDrawColorFilter();
2501    setupDrawShader();
2502    setupDrawBlending(mode);
2503    setupDrawProgram();
2504    setupDrawModelViewIdentity(true);
2505    setupDrawColorUniforms();
2506    setupDrawColorFilterUniforms();
2507    setupDrawPointUniforms();
2508    setupDrawShaderIdentityUniforms();
2509    setupDrawMesh(vertex);
2510
2511    for (int i = 0; i < count; i += 2) {
2512        TextureVertex::set(vertex++, points[i], points[i + 1], 0.0f, 0.0f);
2513        generatedVerticesCount++;
2514
2515        float left = points[i] - halfWidth;
2516        float right = points[i] + halfWidth;
2517        float top = points[i + 1] - halfWidth;
2518        float bottom = points [i + 1] + halfWidth;
2519
2520        dirtyLayer(left, top, right, bottom, currentTransform());
2521    }
2522
2523    glDrawArrays(GL_POINTS, 0, generatedVerticesCount);
2524
2525    return DrawGlInfo::kStatusDrew;
2526}
2527
2528status_t OpenGLRenderer::drawColor(int color, SkXfermode::Mode mode) {
2529    // No need to check against the clip, we fill the clip region
2530    if (mSnapshot->isIgnored()) return DrawGlInfo::kStatusDone;
2531
2532    Rect& clip(*mSnapshot->clipRect);
2533    clip.snapToPixelBoundaries();
2534
2535    drawColorRect(clip.left, clip.top, clip.right, clip.bottom, color, mode, true);
2536
2537    return DrawGlInfo::kStatusDrew;
2538}
2539
2540status_t OpenGLRenderer::drawShape(float left, float top, const PathTexture* texture,
2541        SkPaint* paint) {
2542    if (!texture) return DrawGlInfo::kStatusDone;
2543    const AutoTexture autoCleanup(texture);
2544
2545    const float x = left + texture->left - texture->offset;
2546    const float y = top + texture->top - texture->offset;
2547
2548    drawPathTexture(texture, x, y, paint);
2549
2550    return DrawGlInfo::kStatusDrew;
2551}
2552
2553status_t OpenGLRenderer::drawRoundRect(float left, float top, float right, float bottom,
2554        float rx, float ry, SkPaint* p) {
2555    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p) ||
2556            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
2557        return DrawGlInfo::kStatusDone;
2558    }
2559
2560    if (p->getPathEffect() != 0) {
2561        mCaches.activeTexture(0);
2562        const PathTexture* texture = mCaches.pathCache.getRoundRect(
2563                right - left, bottom - top, rx, ry, p);
2564        return drawShape(left, top, texture, p);
2565    }
2566
2567    SkPath path;
2568    SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
2569    if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2570        float outset = p->getStrokeWidth() / 2;
2571        rect.outset(outset, outset);
2572        rx += outset;
2573        ry += outset;
2574    }
2575    path.addRoundRect(rect, rx, ry);
2576    return drawConvexPath(path, p);
2577}
2578
2579status_t OpenGLRenderer::drawCircle(float x, float y, float radius, SkPaint* p) {
2580    if (mSnapshot->isIgnored() || quickRejectPreStroke(x - radius, y - radius,
2581            x + radius, y + radius, p) ||
2582            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
2583        return DrawGlInfo::kStatusDone;
2584    }
2585    if (p->getPathEffect() != 0) {
2586        mCaches.activeTexture(0);
2587        const PathTexture* texture = mCaches.pathCache.getCircle(radius, p);
2588        return drawShape(x - radius, y - radius, texture, p);
2589    }
2590
2591    SkPath path;
2592    if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2593        path.addCircle(x, y, radius + p->getStrokeWidth() / 2);
2594    } else {
2595        path.addCircle(x, y, radius);
2596    }
2597    return drawConvexPath(path, p);
2598}
2599
2600status_t OpenGLRenderer::drawOval(float left, float top, float right, float bottom,
2601        SkPaint* p) {
2602    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p) ||
2603            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
2604        return DrawGlInfo::kStatusDone;
2605    }
2606
2607    if (p->getPathEffect() != 0) {
2608        mCaches.activeTexture(0);
2609        const PathTexture* texture = mCaches.pathCache.getOval(right - left, bottom - top, p);
2610        return drawShape(left, top, texture, p);
2611    }
2612
2613    SkPath path;
2614    SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
2615    if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2616        rect.outset(p->getStrokeWidth() / 2, p->getStrokeWidth() / 2);
2617    }
2618    path.addOval(rect);
2619    return drawConvexPath(path, p);
2620}
2621
2622status_t OpenGLRenderer::drawArc(float left, float top, float right, float bottom,
2623        float startAngle, float sweepAngle, bool useCenter, SkPaint* p) {
2624    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p) ||
2625            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
2626        return DrawGlInfo::kStatusDone;
2627    }
2628
2629    if (fabs(sweepAngle) >= 360.0f) {
2630        return drawOval(left, top, right, bottom, p);
2631    }
2632
2633    // TODO: support fills (accounting for concavity if useCenter && sweepAngle > 180)
2634    if (p->getStyle() != SkPaint::kStroke_Style || p->getPathEffect() != 0 || useCenter) {
2635        mCaches.activeTexture(0);
2636        const PathTexture* texture = mCaches.pathCache.getArc(right - left, bottom - top,
2637                startAngle, sweepAngle, useCenter, p);
2638        return drawShape(left, top, texture, p);
2639    }
2640
2641    SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
2642    if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2643        rect.outset(p->getStrokeWidth() / 2, p->getStrokeWidth() / 2);
2644    }
2645
2646    SkPath path;
2647    if (useCenter) {
2648        path.moveTo(rect.centerX(), rect.centerY());
2649    }
2650    path.arcTo(rect, startAngle, sweepAngle, !useCenter);
2651    if (useCenter) {
2652        path.close();
2653    }
2654    return drawConvexPath(path, p);
2655}
2656
2657// See SkPaintDefaults.h
2658#define SkPaintDefaults_MiterLimit SkIntToScalar(4)
2659
2660status_t OpenGLRenderer::drawRect(float left, float top, float right, float bottom, SkPaint* p) {
2661    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p) ||
2662            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
2663        return DrawGlInfo::kStatusDone;
2664    }
2665
2666    if (p->getStyle() != SkPaint::kFill_Style) {
2667        // only fill style is supported by drawConvexPath, since others have to handle joins
2668        if (p->getPathEffect() != 0 || p->getStrokeJoin() != SkPaint::kMiter_Join ||
2669                p->getStrokeMiter() != SkPaintDefaults_MiterLimit) {
2670            mCaches.activeTexture(0);
2671            const PathTexture* texture =
2672                    mCaches.pathCache.getRect(right - left, bottom - top, p);
2673            return drawShape(left, top, texture, p);
2674        }
2675
2676        SkPath path;
2677        SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
2678        if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2679            rect.outset(p->getStrokeWidth() / 2, p->getStrokeWidth() / 2);
2680        }
2681        path.addRect(rect);
2682        return drawConvexPath(path, p);
2683    }
2684
2685    if (p->isAntiAlias() && !currentTransform().isSimple()) {
2686        SkPath path;
2687        path.addRect(left, top, right, bottom);
2688        return drawConvexPath(path, p);
2689    } else {
2690        drawColorRect(left, top, right, bottom, p->getColor(), getXfermode(p->getXfermode()));
2691        return DrawGlInfo::kStatusDrew;
2692    }
2693}
2694
2695void OpenGLRenderer::drawTextShadow(SkPaint* paint, const char* text, int bytesCount, int count,
2696        const float* positions, FontRenderer& fontRenderer, int alpha, SkXfermode::Mode mode,
2697        float x, float y) {
2698    mCaches.activeTexture(0);
2699
2700    // NOTE: The drop shadow will not perform gamma correction
2701    //       if shader-based correction is enabled
2702    mCaches.dropShadowCache.setFontRenderer(fontRenderer);
2703    const ShadowTexture* shadow = mCaches.dropShadowCache.get(
2704            paint, text, bytesCount, count, mDrawModifiers.mShadowRadius, positions);
2705    // If the drop shadow exceeds the max texture size or couldn't be
2706    // allocated, skip drawing
2707    if (!shadow) return;
2708    const AutoTexture autoCleanup(shadow);
2709
2710    const float sx = x - shadow->left + mDrawModifiers.mShadowDx;
2711    const float sy = y - shadow->top + mDrawModifiers.mShadowDy;
2712
2713    const int shadowAlpha = ((mDrawModifiers.mShadowColor >> 24) & 0xFF) * mSnapshot->alpha;
2714    int shadowColor = mDrawModifiers.mShadowColor;
2715    if (mDrawModifiers.mShader) {
2716        shadowColor = 0xffffffff;
2717    }
2718
2719    setupDraw();
2720    setupDrawWithTexture(true);
2721    setupDrawAlpha8Color(shadowColor, shadowAlpha < 255 ? shadowAlpha : alpha);
2722    setupDrawColorFilter();
2723    setupDrawShader();
2724    setupDrawBlending(true, mode);
2725    setupDrawProgram();
2726    setupDrawModelView(sx, sy, sx + shadow->width, sy + shadow->height);
2727    setupDrawTexture(shadow->id);
2728    setupDrawPureColorUniforms();
2729    setupDrawColorFilterUniforms();
2730    setupDrawShaderUniforms();
2731    setupDrawMesh(NULL, (GLvoid*) gMeshTextureOffset);
2732
2733    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
2734}
2735
2736bool OpenGLRenderer::canSkipText(const SkPaint* paint) const {
2737    float alpha = (mDrawModifiers.mHasShadow ? 1.0f : paint->getAlpha()) * mSnapshot->alpha;
2738    return alpha == 0.0f && getXfermode(paint->getXfermode()) == SkXfermode::kSrcOver_Mode;
2739}
2740
2741class TextSetupFunctor: public Functor {
2742public:
2743    TextSetupFunctor(OpenGLRenderer& renderer, float x, float y, bool pureTranslate,
2744            int alpha, SkXfermode::Mode mode, SkPaint* paint): Functor(),
2745            renderer(renderer), x(x), y(y), pureTranslate(pureTranslate),
2746            alpha(alpha), mode(mode), paint(paint) {
2747    }
2748    ~TextSetupFunctor() { }
2749
2750    status_t operator ()(int what, void* data) {
2751        renderer.setupDraw();
2752        renderer.setupDrawTextGamma(paint);
2753        renderer.setupDrawDirtyRegionsDisabled();
2754        renderer.setupDrawWithTexture(true);
2755        renderer.setupDrawAlpha8Color(paint->getColor(), alpha);
2756        renderer.setupDrawColorFilter();
2757        renderer.setupDrawShader();
2758        renderer.setupDrawBlending(true, mode);
2759        renderer.setupDrawProgram();
2760        renderer.setupDrawModelView(x, y, x, y, pureTranslate, true);
2761        // Calling setupDrawTexture with the name 0 will enable the
2762        // uv attributes and increase the texture unit count
2763        // texture binding will be performed by the font renderer as
2764        // needed
2765        renderer.setupDrawTexture(0);
2766        renderer.setupDrawPureColorUniforms();
2767        renderer.setupDrawColorFilterUniforms();
2768        renderer.setupDrawShaderUniforms(pureTranslate);
2769        renderer.setupDrawTextGammaUniforms();
2770
2771        return NO_ERROR;
2772    }
2773
2774    OpenGLRenderer& renderer;
2775    float x;
2776    float y;
2777    bool pureTranslate;
2778    int alpha;
2779    SkXfermode::Mode mode;
2780    SkPaint* paint;
2781};
2782
2783status_t OpenGLRenderer::drawPosText(const char* text, int bytesCount, int count,
2784        const float* positions, SkPaint* paint) {
2785    if (text == NULL || count == 0 || mSnapshot->isIgnored() || canSkipText(paint)) {
2786        return DrawGlInfo::kStatusDone;
2787    }
2788
2789    // NOTE: Skia does not support perspective transform on drawPosText yet
2790    if (!currentTransform().isSimple()) {
2791        return DrawGlInfo::kStatusDone;
2792    }
2793
2794    float x = 0.0f;
2795    float y = 0.0f;
2796    const bool pureTranslate = currentTransform().isPureTranslate();
2797    if (pureTranslate) {
2798        x = (int) floorf(x + currentTransform().getTranslateX() + 0.5f);
2799        y = (int) floorf(y + currentTransform().getTranslateY() + 0.5f);
2800    }
2801
2802    FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
2803    fontRenderer.setFont(paint, mat4::identity());
2804
2805    int alpha;
2806    SkXfermode::Mode mode;
2807    getAlphaAndMode(paint, &alpha, &mode);
2808
2809    if (CC_UNLIKELY(mDrawModifiers.mHasShadow)) {
2810        drawTextShadow(paint, text, bytesCount, count, positions, fontRenderer,
2811                alpha, mode, 0.0f, 0.0f);
2812    }
2813
2814    // Pick the appropriate texture filtering
2815    bool linearFilter = currentTransform().changesBounds();
2816    if (pureTranslate && !linearFilter) {
2817        linearFilter = fabs(y - (int) y) > 0.0f || fabs(x - (int) x) > 0.0f;
2818    }
2819    fontRenderer.setTextureFiltering(linearFilter);
2820
2821    const Rect* clip = pureTranslate ? mSnapshot->clipRect : &mSnapshot->getLocalClip();
2822    Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
2823
2824    const bool hasActiveLayer = hasLayer();
2825
2826    TextSetupFunctor functor(*this, x, y, pureTranslate, alpha, mode, paint);
2827    if (fontRenderer.renderPosText(paint, clip, text, 0, bytesCount, count, x, y,
2828            positions, hasActiveLayer ? &bounds : NULL, &functor)) {
2829        if (hasActiveLayer) {
2830            if (!pureTranslate) {
2831                currentTransform().mapRect(bounds);
2832            }
2833            dirtyLayerUnchecked(bounds, getRegion());
2834        }
2835    }
2836
2837    return DrawGlInfo::kStatusDrew;
2838}
2839
2840mat4 OpenGLRenderer::findBestFontTransform(const mat4& transform) const {
2841    mat4 fontTransform;
2842    if (CC_LIKELY(transform.isPureTranslate())) {
2843        fontTransform = mat4::identity();
2844    } else {
2845        if (CC_UNLIKELY(transform.isPerspective())) {
2846            fontTransform = mat4::identity();
2847        } else {
2848            float sx, sy;
2849            currentTransform().decomposeScale(sx, sy);
2850            fontTransform.loadScale(sx, sy, 1.0f);
2851        }
2852    }
2853    return fontTransform;
2854}
2855
2856status_t OpenGLRenderer::drawText(const char* text, int bytesCount, int count,
2857        float x, float y, const float* positions, SkPaint* paint, float length,
2858        DrawOpMode drawOpMode) {
2859
2860    if (drawOpMode == kDrawOpMode_Immediate &&
2861            (text == NULL || count == 0 || mSnapshot->isIgnored() || canSkipText(paint))) {
2862        return DrawGlInfo::kStatusDone;
2863    }
2864
2865    if (length < 0.0f) length = paint->measureText(text, bytesCount);
2866    switch (paint->getTextAlign()) {
2867        case SkPaint::kCenter_Align:
2868            x -= length / 2.0f;
2869            break;
2870        case SkPaint::kRight_Align:
2871            x -= length;
2872            break;
2873        default:
2874            break;
2875    }
2876
2877    SkPaint::FontMetrics metrics;
2878    paint->getFontMetrics(&metrics, 0.0f);
2879    if (drawOpMode == kDrawOpMode_Immediate) {
2880        if (quickReject(x, y + metrics.fTop, x + length, y + metrics.fBottom)) {
2881            return DrawGlInfo::kStatusDone;
2882        }
2883    } else {
2884        // merged draw operations don't need scissor, but clip should still be valid
2885        mCaches.setScissorEnabled(mScissorOptimizationDisabled);
2886    }
2887
2888    const float oldX = x;
2889    const float oldY = y;
2890
2891    const mat4& transform = currentTransform();
2892    const bool pureTranslate = transform.isPureTranslate();
2893
2894    if (CC_LIKELY(pureTranslate)) {
2895        x = (int) floorf(x + transform.getTranslateX() + 0.5f);
2896        y = (int) floorf(y + transform.getTranslateY() + 0.5f);
2897    }
2898
2899    int alpha;
2900    SkXfermode::Mode mode;
2901    getAlphaAndMode(paint, &alpha, &mode);
2902
2903    FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
2904
2905    if (CC_UNLIKELY(mDrawModifiers.mHasShadow)) {
2906        fontRenderer.setFont(paint, mat4::identity());
2907        drawTextShadow(paint, text, bytesCount, count, positions, fontRenderer,
2908                alpha, mode, oldX, oldY);
2909    }
2910
2911    const bool hasActiveLayer = hasLayer();
2912
2913    // We only pass a partial transform to the font renderer. That partial
2914    // matrix defines how glyphs are rasterized. Typically we want glyphs
2915    // to be rasterized at their final size on screen, which means the partial
2916    // matrix needs to take the scale factor into account.
2917    // When a partial matrix is used to transform glyphs during rasterization,
2918    // the mesh is generated with the inverse transform (in the case of scale,
2919    // the mesh is generated at 1.0 / scale for instance.) This allows us to
2920    // apply the full transform matrix at draw time in the vertex shader.
2921    // Applying the full matrix in the shader is the easiest way to handle
2922    // rotation and perspective and allows us to always generated quads in the
2923    // font renderer which greatly simplifies the code, clipping in particular.
2924    mat4 fontTransform = findBestFontTransform(transform);
2925    fontRenderer.setFont(paint, fontTransform);
2926
2927    // Pick the appropriate texture filtering
2928    bool linearFilter = !pureTranslate || fabs(y - (int) y) > 0.0f || fabs(x - (int) x) > 0.0f;
2929    fontRenderer.setTextureFiltering(linearFilter);
2930
2931    // TODO: Implement better clipping for scaled/rotated text
2932    const Rect* clip = !pureTranslate ? NULL : mSnapshot->clipRect;
2933    Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
2934
2935    bool status;
2936    TextSetupFunctor functor(*this, x, y, pureTranslate, alpha, mode, paint);
2937
2938    // don't call issuedrawcommand, do it at end of batch
2939    bool forceFinish = (drawOpMode != kDrawOpMode_Defer);
2940    if (CC_UNLIKELY(paint->getTextAlign() != SkPaint::kLeft_Align)) {
2941        SkPaint paintCopy(*paint);
2942        paintCopy.setTextAlign(SkPaint::kLeft_Align);
2943        status = fontRenderer.renderPosText(&paintCopy, clip, text, 0, bytesCount, count, x, y,
2944                positions, hasActiveLayer ? &bounds : NULL, &functor, forceFinish);
2945    } else {
2946        status = fontRenderer.renderPosText(paint, clip, text, 0, bytesCount, count, x, y,
2947                positions, hasActiveLayer ? &bounds : NULL, &functor, forceFinish);
2948    }
2949
2950    if ((status || drawOpMode != kDrawOpMode_Immediate) && hasActiveLayer) {
2951        if (!pureTranslate) {
2952            transform.mapRect(bounds);
2953        }
2954        dirtyLayerUnchecked(bounds, getRegion());
2955    }
2956
2957    drawTextDecorations(text, bytesCount, length, oldX, oldY, paint);
2958
2959    return DrawGlInfo::kStatusDrew;
2960}
2961
2962status_t OpenGLRenderer::drawTextOnPath(const char* text, int bytesCount, int count, SkPath* path,
2963        float hOffset, float vOffset, SkPaint* paint) {
2964    if (text == NULL || count == 0 || mSnapshot->isIgnored() || canSkipText(paint)) {
2965        return DrawGlInfo::kStatusDone;
2966    }
2967
2968    FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
2969    fontRenderer.setFont(paint, mat4::identity());
2970    fontRenderer.setTextureFiltering(true);
2971
2972    int alpha;
2973    SkXfermode::Mode mode;
2974    getAlphaAndMode(paint, &alpha, &mode);
2975
2976    setupDraw();
2977    setupDrawTextGamma(paint);
2978    setupDrawDirtyRegionsDisabled();
2979    setupDrawWithTexture(true);
2980    setupDrawAlpha8Color(paint->getColor(), alpha);
2981    setupDrawColorFilter();
2982    setupDrawShader();
2983    setupDrawBlending(true, mode);
2984    setupDrawProgram();
2985    setupDrawModelView(0.0f, 0.0f, 0.0f, 0.0f, false, true);
2986    // Calling setupDrawTexture with the name 0 will enable the
2987    // uv attributes and increase the texture unit count
2988    // texture binding will be performed by the font renderer as
2989    // needed
2990    setupDrawTexture(0);
2991    setupDrawPureColorUniforms();
2992    setupDrawColorFilterUniforms();
2993    setupDrawShaderUniforms(false);
2994    setupDrawTextGammaUniforms();
2995
2996    const Rect* clip = &mSnapshot->getLocalClip();
2997    Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
2998
2999    const bool hasActiveLayer = hasLayer();
3000
3001    if (fontRenderer.renderTextOnPath(paint, clip, text, 0, bytesCount, count, path,
3002            hOffset, vOffset, hasActiveLayer ? &bounds : NULL)) {
3003        if (hasActiveLayer) {
3004            currentTransform().mapRect(bounds);
3005            dirtyLayerUnchecked(bounds, getRegion());
3006        }
3007    }
3008
3009    return DrawGlInfo::kStatusDrew;
3010}
3011
3012status_t OpenGLRenderer::drawPath(SkPath* path, SkPaint* paint) {
3013    if (mSnapshot->isIgnored()) return DrawGlInfo::kStatusDone;
3014
3015    mCaches.activeTexture(0);
3016
3017    const PathTexture* texture = mCaches.pathCache.get(path, paint);
3018    if (!texture) return DrawGlInfo::kStatusDone;
3019    const AutoTexture autoCleanup(texture);
3020
3021    const float x = texture->left - texture->offset;
3022    const float y = texture->top - texture->offset;
3023
3024    drawPathTexture(texture, x, y, paint);
3025
3026    return DrawGlInfo::kStatusDrew;
3027}
3028
3029status_t OpenGLRenderer::drawLayer(Layer* layer, float x, float y) {
3030    if (!layer) {
3031        return DrawGlInfo::kStatusDone;
3032    }
3033
3034    mat4* transform = NULL;
3035    if (layer->isTextureLayer()) {
3036        transform = &layer->getTransform();
3037        if (!transform->isIdentity()) {
3038            save(0);
3039            currentTransform().multiply(*transform);
3040        }
3041    }
3042
3043    Rect transformed;
3044    Rect clip;
3045    const bool rejected = quickRejectNoScissor(x, y,
3046            x + layer->layer.getWidth(), y + layer->layer.getHeight(), transformed, clip);
3047
3048    if (rejected) {
3049        if (transform && !transform->isIdentity()) {
3050            restore();
3051        }
3052        return DrawGlInfo::kStatusDone;
3053    }
3054
3055    updateLayer(layer, true);
3056
3057    mCaches.setScissorEnabled(mScissorOptimizationDisabled || !clip.contains(transformed));
3058    mCaches.activeTexture(0);
3059
3060    if (CC_LIKELY(!layer->region.isEmpty())) {
3061        SkiaColorFilter* oldFilter = mDrawModifiers.mColorFilter;
3062        mDrawModifiers.mColorFilter = layer->getColorFilter();
3063
3064        if (layer->region.isRect()) {
3065            DRAW_DOUBLE_STENCIL_IF(!layer->hasDrawnSinceUpdate,
3066                    composeLayerRect(layer, layer->regionRect));
3067        } else if (layer->mesh) {
3068            const float a = getLayerAlpha(layer);
3069            setupDraw();
3070            setupDrawWithTexture();
3071            setupDrawColor(a, a, a, a);
3072            setupDrawColorFilter();
3073            setupDrawBlending(layer->isBlend() || a < 1.0f, layer->getMode(), false);
3074            setupDrawProgram();
3075            setupDrawPureColorUniforms();
3076            setupDrawColorFilterUniforms();
3077            setupDrawTexture(layer->getTexture());
3078            if (CC_LIKELY(currentTransform().isPureTranslate())) {
3079                int tx = (int) floorf(x + currentTransform().getTranslateX() + 0.5f);
3080                int ty = (int) floorf(y + currentTransform().getTranslateY() + 0.5f);
3081
3082                layer->setFilter(GL_NEAREST);
3083                setupDrawModelViewTranslate(tx, ty,
3084                        tx + layer->layer.getWidth(), ty + layer->layer.getHeight(), true);
3085            } else {
3086                layer->setFilter(GL_LINEAR);
3087                setupDrawModelViewTranslate(x, y,
3088                        x + layer->layer.getWidth(), y + layer->layer.getHeight());
3089            }
3090            setupDrawMesh(&layer->mesh[0].position[0], &layer->mesh[0].texture[0]);
3091
3092            DRAW_DOUBLE_STENCIL_IF(!layer->hasDrawnSinceUpdate,
3093                    glDrawElements(GL_TRIANGLES, layer->meshElementCount,
3094                            GL_UNSIGNED_SHORT, layer->meshIndices));
3095
3096            finishDrawTexture();
3097
3098#if DEBUG_LAYERS_AS_REGIONS
3099            drawRegionRects(layer->region);
3100#endif
3101        }
3102
3103        mDrawModifiers.mColorFilter = oldFilter;
3104
3105        if (layer->debugDrawUpdate) {
3106            layer->debugDrawUpdate = false;
3107            drawColorRect(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight(),
3108                    0x7f00ff00, SkXfermode::kSrcOver_Mode);
3109        }
3110    }
3111    layer->hasDrawnSinceUpdate = true;
3112
3113    if (transform && !transform->isIdentity()) {
3114        restore();
3115    }
3116
3117    return DrawGlInfo::kStatusDrew;
3118}
3119
3120///////////////////////////////////////////////////////////////////////////////
3121// Shaders
3122///////////////////////////////////////////////////////////////////////////////
3123
3124void OpenGLRenderer::resetShader() {
3125    mDrawModifiers.mShader = NULL;
3126}
3127
3128void OpenGLRenderer::setupShader(SkiaShader* shader) {
3129    mDrawModifiers.mShader = shader;
3130    if (mDrawModifiers.mShader) {
3131        mDrawModifiers.mShader->set(&mCaches.textureCache, &mCaches.gradientCache);
3132    }
3133}
3134
3135///////////////////////////////////////////////////////////////////////////////
3136// Color filters
3137///////////////////////////////////////////////////////////////////////////////
3138
3139void OpenGLRenderer::resetColorFilter() {
3140    mDrawModifiers.mColorFilter = NULL;
3141}
3142
3143void OpenGLRenderer::setupColorFilter(SkiaColorFilter* filter) {
3144    mDrawModifiers.mColorFilter = filter;
3145}
3146
3147///////////////////////////////////////////////////////////////////////////////
3148// Drop shadow
3149///////////////////////////////////////////////////////////////////////////////
3150
3151void OpenGLRenderer::resetShadow() {
3152    mDrawModifiers.mHasShadow = false;
3153}
3154
3155void OpenGLRenderer::setupShadow(float radius, float dx, float dy, int color) {
3156    mDrawModifiers.mHasShadow = true;
3157    mDrawModifiers.mShadowRadius = radius;
3158    mDrawModifiers.mShadowDx = dx;
3159    mDrawModifiers.mShadowDy = dy;
3160    mDrawModifiers.mShadowColor = color;
3161}
3162
3163///////////////////////////////////////////////////////////////////////////////
3164// Draw filters
3165///////////////////////////////////////////////////////////////////////////////
3166
3167void OpenGLRenderer::resetPaintFilter() {
3168    // when clearing the PaintFilter, the masks should also be cleared for simple DrawModifier
3169    // comparison, see MergingDrawBatch::canMergeWith
3170    mDrawModifiers.mHasDrawFilter = false;
3171    mDrawModifiers.mPaintFilterClearBits = 0;
3172    mDrawModifiers.mPaintFilterSetBits = 0;
3173}
3174
3175void OpenGLRenderer::setupPaintFilter(int clearBits, int setBits) {
3176    mDrawModifiers.mHasDrawFilter = true;
3177    mDrawModifiers.mPaintFilterClearBits = clearBits & SkPaint::kAllFlags;
3178    mDrawModifiers.mPaintFilterSetBits = setBits & SkPaint::kAllFlags;
3179}
3180
3181SkPaint* OpenGLRenderer::filterPaint(SkPaint* paint) {
3182    if (CC_LIKELY(!mDrawModifiers.mHasDrawFilter || !paint)) {
3183        return paint;
3184    }
3185
3186    uint32_t flags = paint->getFlags();
3187
3188    mFilteredPaint = *paint;
3189    mFilteredPaint.setFlags((flags & ~mDrawModifiers.mPaintFilterClearBits) |
3190            mDrawModifiers.mPaintFilterSetBits);
3191
3192    return &mFilteredPaint;
3193}
3194
3195///////////////////////////////////////////////////////////////////////////////
3196// Drawing implementation
3197///////////////////////////////////////////////////////////////////////////////
3198
3199void OpenGLRenderer::drawPathTexture(const PathTexture* texture,
3200        float x, float y, SkPaint* paint) {
3201    if (quickReject(x, y, x + texture->width, y + texture->height)) {
3202        return;
3203    }
3204
3205    int alpha;
3206    SkXfermode::Mode mode;
3207    getAlphaAndMode(paint, &alpha, &mode);
3208
3209    setupDraw();
3210    setupDrawWithTexture(true);
3211    setupDrawAlpha8Color(paint->getColor(), alpha);
3212    setupDrawColorFilter();
3213    setupDrawShader();
3214    setupDrawBlending(true, mode);
3215    setupDrawProgram();
3216    setupDrawModelView(x, y, x + texture->width, y + texture->height);
3217    setupDrawTexture(texture->id);
3218    setupDrawPureColorUniforms();
3219    setupDrawColorFilterUniforms();
3220    setupDrawShaderUniforms();
3221    setupDrawMesh(NULL, (GLvoid*) gMeshTextureOffset);
3222
3223    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
3224
3225    finishDrawTexture();
3226}
3227
3228// Same values used by Skia
3229#define kStdStrikeThru_Offset   (-6.0f / 21.0f)
3230#define kStdUnderline_Offset    (1.0f / 9.0f)
3231#define kStdUnderline_Thickness (1.0f / 18.0f)
3232
3233void OpenGLRenderer::drawTextDecorations(const char* text, int bytesCount, float length,
3234        float x, float y, SkPaint* paint) {
3235    // Handle underline and strike-through
3236    uint32_t flags = paint->getFlags();
3237    if (flags & (SkPaint::kUnderlineText_Flag | SkPaint::kStrikeThruText_Flag)) {
3238        SkPaint paintCopy(*paint);
3239        float underlineWidth = length;
3240        // If length is > 0.0f, we already measured the text for the text alignment
3241        if (length <= 0.0f) {
3242            underlineWidth = paintCopy.measureText(text, bytesCount);
3243        }
3244
3245        if (CC_LIKELY(underlineWidth > 0.0f)) {
3246            const float textSize = paintCopy.getTextSize();
3247            const float strokeWidth = fmax(textSize * kStdUnderline_Thickness, 1.0f);
3248
3249            const float left = x;
3250            float top = 0.0f;
3251
3252            int linesCount = 0;
3253            if (flags & SkPaint::kUnderlineText_Flag) linesCount++;
3254            if (flags & SkPaint::kStrikeThruText_Flag) linesCount++;
3255
3256            const int pointsCount = 4 * linesCount;
3257            float points[pointsCount];
3258            int currentPoint = 0;
3259
3260            if (flags & SkPaint::kUnderlineText_Flag) {
3261                top = y + textSize * kStdUnderline_Offset;
3262                points[currentPoint++] = left;
3263                points[currentPoint++] = top;
3264                points[currentPoint++] = left + underlineWidth;
3265                points[currentPoint++] = top;
3266            }
3267
3268            if (flags & SkPaint::kStrikeThruText_Flag) {
3269                top = y + textSize * kStdStrikeThru_Offset;
3270                points[currentPoint++] = left;
3271                points[currentPoint++] = top;
3272                points[currentPoint++] = left + underlineWidth;
3273                points[currentPoint++] = top;
3274            }
3275
3276            paintCopy.setStrokeWidth(strokeWidth);
3277
3278            drawLines(&points[0], pointsCount, &paintCopy);
3279        }
3280    }
3281}
3282
3283status_t OpenGLRenderer::drawRects(const float* rects, int count, SkPaint* paint) {
3284    if (mSnapshot->isIgnored()) {
3285        return DrawGlInfo::kStatusDone;
3286    }
3287
3288    int color = paint->getColor();
3289    // If a shader is set, preserve only the alpha
3290    if (mDrawModifiers.mShader) {
3291        color |= 0x00ffffff;
3292    }
3293    SkXfermode::Mode mode = getXfermode(paint->getXfermode());
3294
3295    return drawColorRects(rects, count, color, mode);
3296}
3297
3298status_t OpenGLRenderer::drawColorRects(const float* rects, int count, int color,
3299        SkXfermode::Mode mode, bool ignoreTransform, bool dirty, bool clip) {
3300    if (count == 0) {
3301        return DrawGlInfo::kStatusDone;
3302    }
3303
3304    float left = FLT_MAX;
3305    float top = FLT_MAX;
3306    float right = FLT_MIN;
3307    float bottom = FLT_MIN;
3308
3309    int vertexCount = 0;
3310    Vertex mesh[count * 6];
3311    Vertex* vertex = mesh;
3312
3313    for (int index = 0; index < count; index += 4) {
3314        float l = rects[index + 0];
3315        float t = rects[index + 1];
3316        float r = rects[index + 2];
3317        float b = rects[index + 3];
3318
3319        Vertex::set(vertex++, l, b);
3320        Vertex::set(vertex++, l, t);
3321        Vertex::set(vertex++, r, t);
3322        Vertex::set(vertex++, l, b);
3323        Vertex::set(vertex++, r, t);
3324        Vertex::set(vertex++, r, b);
3325
3326        vertexCount += 6;
3327
3328        left = fminf(left, l);
3329        top = fminf(top, t);
3330        right = fmaxf(right, r);
3331        bottom = fmaxf(bottom, b);
3332    }
3333
3334    if (clip && quickReject(left, top, right, bottom)) {
3335        return DrawGlInfo::kStatusDone;
3336    }
3337
3338    setupDraw();
3339    setupDrawNoTexture();
3340    setupDrawColor(color, ((color >> 24) & 0xFF) * mSnapshot->alpha);
3341    setupDrawShader();
3342    setupDrawColorFilter();
3343    setupDrawBlending(mode);
3344    setupDrawProgram();
3345    setupDrawDirtyRegionsDisabled();
3346    setupDrawModelView(0.0f, 0.0f, 1.0f, 1.0f, ignoreTransform, true);
3347    setupDrawColorUniforms();
3348    setupDrawShaderUniforms();
3349    setupDrawColorFilterUniforms();
3350    setupDrawVertices((GLvoid*) &mesh[0].position[0]);
3351
3352    if (dirty && hasLayer()) {
3353        dirtyLayer(left, top, right, bottom, currentTransform());
3354    }
3355
3356    glDrawArrays(GL_TRIANGLES, 0, vertexCount);
3357
3358    return DrawGlInfo::kStatusDrew;
3359}
3360
3361void OpenGLRenderer::drawColorRect(float left, float top, float right, float bottom,
3362        int color, SkXfermode::Mode mode, bool ignoreTransform) {
3363    // If a shader is set, preserve only the alpha
3364    if (mDrawModifiers.mShader) {
3365        color |= 0x00ffffff;
3366    }
3367
3368    setupDraw();
3369    setupDrawNoTexture();
3370    setupDrawColor(color, ((color >> 24) & 0xFF) * mSnapshot->alpha);
3371    setupDrawShader();
3372    setupDrawColorFilter();
3373    setupDrawBlending(mode);
3374    setupDrawProgram();
3375    setupDrawModelView(left, top, right, bottom, ignoreTransform);
3376    setupDrawColorUniforms();
3377    setupDrawShaderUniforms(ignoreTransform);
3378    setupDrawColorFilterUniforms();
3379    setupDrawSimpleMesh();
3380
3381    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
3382}
3383
3384void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom,
3385        Texture* texture, SkPaint* paint) {
3386    int alpha;
3387    SkXfermode::Mode mode;
3388    getAlphaAndMode(paint, &alpha, &mode);
3389
3390    texture->setWrap(GL_CLAMP_TO_EDGE, true);
3391
3392    if (CC_LIKELY(currentTransform().isPureTranslate())) {
3393        const float x = (int) floorf(left + currentTransform().getTranslateX() + 0.5f);
3394        const float y = (int) floorf(top + currentTransform().getTranslateY() + 0.5f);
3395
3396        texture->setFilter(GL_NEAREST, true);
3397        drawTextureMesh(x, y, x + texture->width, y + texture->height, texture->id,
3398                alpha / 255.0f, mode, texture->blend, (GLvoid*) NULL,
3399                (GLvoid*) gMeshTextureOffset, GL_TRIANGLE_STRIP, gMeshCount, false, true);
3400    } else {
3401        texture->setFilter(FILTER(paint), true);
3402        drawTextureMesh(left, top, right, bottom, texture->id, alpha / 255.0f, mode,
3403                texture->blend, (GLvoid*) NULL, (GLvoid*) gMeshTextureOffset,
3404                GL_TRIANGLE_STRIP, gMeshCount);
3405    }
3406}
3407
3408void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom,
3409        GLuint texture, float alpha, SkXfermode::Mode mode, bool blend) {
3410    drawTextureMesh(left, top, right, bottom, texture, alpha, mode, blend,
3411            (GLvoid*) NULL, (GLvoid*) gMeshTextureOffset, GL_TRIANGLE_STRIP, gMeshCount);
3412}
3413
3414void OpenGLRenderer::drawTextureMesh(float left, float top, float right, float bottom,
3415        GLuint texture, float alpha, SkXfermode::Mode mode, bool blend,
3416        GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
3417        bool swapSrcDst, bool ignoreTransform, GLuint vbo, bool ignoreScale, bool dirty) {
3418
3419    setupDraw();
3420    setupDrawWithTexture();
3421    setupDrawColor(alpha, alpha, alpha, alpha);
3422    setupDrawColorFilter();
3423    setupDrawBlending(blend, mode, swapSrcDst);
3424    setupDrawProgram();
3425    if (!dirty) setupDrawDirtyRegionsDisabled();
3426    if (!ignoreScale) {
3427        setupDrawModelView(left, top, right, bottom, ignoreTransform);
3428    } else {
3429        setupDrawModelViewTranslate(left, top, right, bottom, ignoreTransform);
3430    }
3431    setupDrawTexture(texture);
3432    setupDrawPureColorUniforms();
3433    setupDrawColorFilterUniforms();
3434    setupDrawMesh(vertices, texCoords, vbo);
3435
3436    glDrawArrays(drawMode, 0, elementsCount);
3437
3438    finishDrawTexture();
3439}
3440
3441void OpenGLRenderer::drawAlpha8TextureMesh(float left, float top, float right, float bottom,
3442        GLuint texture, bool hasColor, int color, int alpha, SkXfermode::Mode mode,
3443        GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
3444        bool ignoreTransform, bool ignoreScale, bool dirty) {
3445
3446    setupDraw();
3447    setupDrawWithTexture(true);
3448    if (hasColor) {
3449        setupDrawAlpha8Color(color, alpha);
3450    }
3451    setupDrawColorFilter();
3452    setupDrawShader();
3453    setupDrawBlending(true, mode);
3454    setupDrawProgram();
3455    if (!dirty) setupDrawDirtyRegionsDisabled();
3456    if (!ignoreScale) {
3457        setupDrawModelView(left, top, right, bottom, ignoreTransform);
3458    } else {
3459        setupDrawModelViewTranslate(left, top, right, bottom, ignoreTransform);
3460    }
3461    setupDrawTexture(texture);
3462    setupDrawPureColorUniforms();
3463    setupDrawColorFilterUniforms();
3464    setupDrawShaderUniforms();
3465    setupDrawMesh(vertices, texCoords);
3466
3467    glDrawArrays(drawMode, 0, elementsCount);
3468
3469    finishDrawTexture();
3470}
3471
3472void OpenGLRenderer::chooseBlending(bool blend, SkXfermode::Mode mode,
3473        ProgramDescription& description, bool swapSrcDst) {
3474    blend = blend || mode != SkXfermode::kSrcOver_Mode;
3475
3476    if (blend) {
3477        // These blend modes are not supported by OpenGL directly and have
3478        // to be implemented using shaders. Since the shader will perform
3479        // the blending, turn blending off here
3480        // If the blend mode cannot be implemented using shaders, fall
3481        // back to the default SrcOver blend mode instead
3482        if (CC_UNLIKELY(mode > SkXfermode::kScreen_Mode)) {
3483            if (CC_UNLIKELY(mExtensions.hasFramebufferFetch())) {
3484                description.framebufferMode = mode;
3485                description.swapSrcDst = swapSrcDst;
3486
3487                if (mCaches.blend) {
3488                    glDisable(GL_BLEND);
3489                    mCaches.blend = false;
3490                }
3491
3492                return;
3493            } else {
3494                mode = SkXfermode::kSrcOver_Mode;
3495            }
3496        }
3497
3498        if (!mCaches.blend) {
3499            glEnable(GL_BLEND);
3500        }
3501
3502        GLenum sourceMode = swapSrcDst ? gBlendsSwap[mode].src : gBlends[mode].src;
3503        GLenum destMode = swapSrcDst ? gBlendsSwap[mode].dst : gBlends[mode].dst;
3504
3505        if (sourceMode != mCaches.lastSrcMode || destMode != mCaches.lastDstMode) {
3506            glBlendFunc(sourceMode, destMode);
3507            mCaches.lastSrcMode = sourceMode;
3508            mCaches.lastDstMode = destMode;
3509        }
3510    } else if (mCaches.blend) {
3511        glDisable(GL_BLEND);
3512    }
3513    mCaches.blend = blend;
3514}
3515
3516bool OpenGLRenderer::useProgram(Program* program) {
3517    if (!program->isInUse()) {
3518        if (mCaches.currentProgram != NULL) mCaches.currentProgram->remove();
3519        program->use();
3520        mCaches.currentProgram = program;
3521        return false;
3522    }
3523    return true;
3524}
3525
3526void OpenGLRenderer::resetDrawTextureTexCoords(float u1, float v1, float u2, float v2) {
3527    TextureVertex* v = &mMeshVertices[0];
3528    TextureVertex::setUV(v++, u1, v1);
3529    TextureVertex::setUV(v++, u2, v1);
3530    TextureVertex::setUV(v++, u1, v2);
3531    TextureVertex::setUV(v++, u2, v2);
3532}
3533
3534void OpenGLRenderer::getAlphaAndMode(SkPaint* paint, int* alpha, SkXfermode::Mode* mode) const {
3535    getAlphaAndModeDirect(paint, alpha,  mode);
3536    if (mDrawModifiers.mOverrideLayerAlpha < 1.0f) {
3537        // if drawing a layer, ignore the paint's alpha
3538        *alpha = mDrawModifiers.mOverrideLayerAlpha;
3539    }
3540    *alpha *= mSnapshot->alpha;
3541}
3542
3543float OpenGLRenderer::getLayerAlpha(Layer* layer) const {
3544    float alpha;
3545    if (mDrawModifiers.mOverrideLayerAlpha < 1.0f) {
3546        alpha = mDrawModifiers.mOverrideLayerAlpha;
3547    } else {
3548        alpha = layer->getAlpha() / 255.0f;
3549    }
3550    return alpha * mSnapshot->alpha;
3551}
3552
3553}; // namespace uirenderer
3554}; // namespace android
3555