OpenGLRenderer.cpp revision b254c242d98f4a9d98055726446351e52bece2c6 
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                // Workaround for some GL drivers. When reading pixels lying outside
886                // of the window we should get undefined values for those pixels.
887                // Unfortunately some drivers will turn the entire target texture black
888                // when reading outside of the window.
889                glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, layer->getWidth(), layer->getHeight(),
890                        0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
891                layer->setEmpty(false);
892            }
893
894            glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, bounds.left,
895                    mSnapshot->height - bounds.bottom, bounds.getWidth(), bounds.getHeight());
896
897            // Enqueue the buffer coordinates to clear the corresponding region later
898            mLayers.push(new Rect(bounds));
899        }
900    }
901
902    return true;
903}
904
905bool OpenGLRenderer::createFboLayer(Layer* layer, Rect& bounds, Rect& clip, GLuint previousFbo) {
906    layer->clipRect.set(clip);
907    layer->setFbo(mCaches.fboCache.get());
908
909    mSnapshot->region = &mSnapshot->layer->region;
910    mSnapshot->flags |= Snapshot::kFlagFboTarget | Snapshot::kFlagIsFboLayer |
911            Snapshot::kFlagDirtyOrtho;
912    mSnapshot->fbo = layer->getFbo();
913    mSnapshot->resetTransform(-bounds.left, -bounds.top, 0.0f);
914    mSnapshot->resetClip(clip.left, clip.top, clip.right, clip.bottom);
915    mSnapshot->viewport.set(0.0f, 0.0f, bounds.getWidth(), bounds.getHeight());
916    mSnapshot->height = bounds.getHeight();
917    mSnapshot->orthoMatrix.load(mOrthoMatrix);
918
919    endTiling();
920    debugOverdraw(false, false);
921    // Bind texture to FBO
922    glBindFramebuffer(GL_FRAMEBUFFER, layer->getFbo());
923    layer->bindTexture();
924
925    // Initialize the texture if needed
926    if (layer->isEmpty()) {
927        layer->allocateTexture();
928        layer->setEmpty(false);
929    }
930
931    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
932            layer->getTexture(), 0);
933
934    startTiling(mSnapshot, true);
935
936    // Clear the FBO, expand the clear region by 1 to get nice bilinear filtering
937    mCaches.enableScissor();
938    mCaches.setScissor(clip.left - 1.0f, bounds.getHeight() - clip.bottom - 1.0f,
939            clip.getWidth() + 2.0f, clip.getHeight() + 2.0f);
940    glClear(GL_COLOR_BUFFER_BIT);
941
942    dirtyClip();
943
944    // Change the ortho projection
945    glViewport(0, 0, bounds.getWidth(), bounds.getHeight());
946    mOrthoMatrix.loadOrtho(0.0f, bounds.getWidth(), bounds.getHeight(), 0.0f, -1.0f, 1.0f);
947
948    return true;
949}
950
951/**
952 * Read the documentation of createLayer() before doing anything in this method.
953 */
954void OpenGLRenderer::composeLayer(sp<Snapshot> current, sp<Snapshot> previous) {
955    if (!current->layer) {
956        ALOGE("Attempting to compose a layer that does not exist");
957        return;
958    }
959
960    Layer* layer = current->layer;
961    const Rect& rect = layer->layer;
962    const bool fboLayer = current->flags & Snapshot::kFlagIsFboLayer;
963
964    if (fboLayer) {
965        endTiling();
966
967        // Detach the texture from the FBO
968        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 0, 0);
969
970        layer->removeFbo(false);
971
972        // Unbind current FBO and restore previous one
973        glBindFramebuffer(GL_FRAMEBUFFER, previous->fbo);
974        debugOverdraw(true, false);
975
976        startTiling(previous);
977    }
978
979    if (!fboLayer && layer->getAlpha() < 255) {
980        drawColorRect(rect.left, rect.top, rect.right, rect.bottom,
981                layer->getAlpha() << 24, SkXfermode::kDstIn_Mode, true);
982        // Required below, composeLayerRect() will divide by 255
983        layer->setAlpha(255);
984    }
985
986    mCaches.unbindMeshBuffer();
987
988    mCaches.activeTexture(0);
989
990    // When the layer is stored in an FBO, we can save a bit of fillrate by
991    // drawing only the dirty region
992    if (fboLayer) {
993        dirtyLayer(rect.left, rect.top, rect.right, rect.bottom, *previous->transform);
994        if (layer->getColorFilter()) {
995            setupColorFilter(layer->getColorFilter());
996        }
997        composeLayerRegion(layer, rect);
998        if (layer->getColorFilter()) {
999            resetColorFilter();
1000        }
1001    } else if (!rect.isEmpty()) {
1002        dirtyLayer(rect.left, rect.top, rect.right, rect.bottom);
1003        composeLayerRect(layer, rect, true);
1004    }
1005
1006    dirtyClip();
1007
1008    // Failing to add the layer to the cache should happen only if the layer is too large
1009    if (!mCaches.layerCache.put(layer)) {
1010        LAYER_LOGD("Deleting layer");
1011        Caches::getInstance().resourceCache.decrementRefcount(layer);
1012    }
1013}
1014
1015void OpenGLRenderer::drawTextureLayer(Layer* layer, const Rect& rect) {
1016    float alpha = layer->getAlpha() / 255.0f * mSnapshot->alpha;
1017
1018    setupDraw();
1019    if (layer->getRenderTarget() == GL_TEXTURE_2D) {
1020        setupDrawWithTexture();
1021    } else {
1022        setupDrawWithExternalTexture();
1023    }
1024    setupDrawTextureTransform();
1025    setupDrawColor(alpha, alpha, alpha, alpha);
1026    setupDrawColorFilter();
1027    setupDrawBlending(layer->isBlend() || alpha < 1.0f, layer->getMode());
1028    setupDrawProgram();
1029    setupDrawPureColorUniforms();
1030    setupDrawColorFilterUniforms();
1031    if (layer->getRenderTarget() == GL_TEXTURE_2D) {
1032        setupDrawTexture(layer->getTexture());
1033    } else {
1034        setupDrawExternalTexture(layer->getTexture());
1035    }
1036    if (currentTransform().isPureTranslate() &&
1037            layer->getWidth() == (uint32_t) rect.getWidth() &&
1038            layer->getHeight() == (uint32_t) rect.getHeight()) {
1039        const float x = (int) floorf(rect.left + currentTransform().getTranslateX() + 0.5f);
1040        const float y = (int) floorf(rect.top + currentTransform().getTranslateY() + 0.5f);
1041
1042        layer->setFilter(GL_NEAREST);
1043        setupDrawModelView(x, y, x + rect.getWidth(), y + rect.getHeight(), true);
1044    } else {
1045        layer->setFilter(GL_LINEAR);
1046        setupDrawModelView(rect.left, rect.top, rect.right, rect.bottom);
1047    }
1048    setupDrawTextureTransformUniforms(layer->getTexTransform());
1049    setupDrawMesh(&mMeshVertices[0].position[0], &mMeshVertices[0].texture[0]);
1050
1051    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
1052
1053    finishDrawTexture();
1054}
1055
1056void OpenGLRenderer::composeLayerRect(Layer* layer, const Rect& rect, bool swap) {
1057    if (!layer->isTextureLayer()) {
1058        const Rect& texCoords = layer->texCoords;
1059        resetDrawTextureTexCoords(texCoords.left, texCoords.top,
1060                texCoords.right, texCoords.bottom);
1061
1062        float x = rect.left;
1063        float y = rect.top;
1064        bool simpleTransform = currentTransform().isPureTranslate() &&
1065                layer->getWidth() == (uint32_t) rect.getWidth() &&
1066                layer->getHeight() == (uint32_t) rect.getHeight();
1067
1068        if (simpleTransform) {
1069            // When we're swapping, the layer is already in screen coordinates
1070            if (!swap) {
1071                x = (int) floorf(rect.left + currentTransform().getTranslateX() + 0.5f);
1072                y = (int) floorf(rect.top + currentTransform().getTranslateY() + 0.5f);
1073            }
1074
1075            layer->setFilter(GL_NEAREST, true);
1076        } else {
1077            layer->setFilter(GL_LINEAR, true);
1078        }
1079
1080        float alpha = getLayerAlpha(layer);
1081        bool blend = layer->isBlend() || alpha < 1.0f;
1082        drawTextureMesh(x, y, x + rect.getWidth(), y + rect.getHeight(),
1083                layer->getTexture(), alpha, layer->getMode(), blend,
1084                &mMeshVertices[0].position[0], &mMeshVertices[0].texture[0],
1085                GL_TRIANGLE_STRIP, gMeshCount, swap, swap || simpleTransform);
1086
1087        resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
1088    } else {
1089        resetDrawTextureTexCoords(0.0f, 1.0f, 1.0f, 0.0f);
1090        drawTextureLayer(layer, rect);
1091        resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
1092    }
1093}
1094
1095/**
1096 * Issues the command X, and if we're composing a save layer to the fbo or drawing a newly updated
1097 * hardware layer with overdraw debug on, draws again to the stencil only, so that these draw
1098 * operations are correctly counted twice for overdraw. NOTE: assumes composeLayerRegion only used
1099 * by saveLayer's restore
1100 */
1101#define DRAW_DOUBLE_STENCIL_IF(COND, DRAW_COMMAND) {                             \
1102        DRAW_COMMAND;                                                            \
1103        if (CC_UNLIKELY(mCaches.debugOverdraw && getTargetFbo() == 0 && COND)) { \
1104            glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);                 \
1105            DRAW_COMMAND;                                                        \
1106            glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);                     \
1107        }                                                                        \
1108    }
1109
1110#define DRAW_DOUBLE_STENCIL(DRAW_COMMAND) DRAW_DOUBLE_STENCIL_IF(true, DRAW_COMMAND)
1111
1112void OpenGLRenderer::composeLayerRegion(Layer* layer, const Rect& rect) {
1113    if (layer->region.isRect()) {
1114        layer->setRegionAsRect();
1115
1116        DRAW_DOUBLE_STENCIL(composeLayerRect(layer, layer->regionRect));
1117
1118        layer->region.clear();
1119        return;
1120    }
1121
1122    // TODO: See LayerRenderer.cpp::generateMesh() for important
1123    //       information about this implementation
1124    if (CC_LIKELY(!layer->region.isEmpty())) {
1125        size_t count;
1126        const android::Rect* rects;
1127        Region safeRegion;
1128        if (CC_LIKELY(hasRectToRectTransform())) {
1129            rects = layer->region.getArray(&count);
1130        } else {
1131            safeRegion = Region::createTJunctionFreeRegion(layer->region);
1132            rects = safeRegion.getArray(&count);
1133        }
1134
1135        const float alpha = getLayerAlpha(layer);
1136        const float texX = 1.0f / float(layer->getWidth());
1137        const float texY = 1.0f / float(layer->getHeight());
1138        const float height = rect.getHeight();
1139
1140        setupDraw();
1141
1142        // We must get (and therefore bind) the region mesh buffer
1143        // after we setup drawing in case we need to mess with the
1144        // stencil buffer in setupDraw()
1145        TextureVertex* mesh = mCaches.getRegionMesh();
1146        GLsizei numQuads = 0;
1147
1148        setupDrawWithTexture();
1149        setupDrawColor(alpha, alpha, alpha, alpha);
1150        setupDrawColorFilter();
1151        setupDrawBlending(layer->isBlend() || alpha < 1.0f, layer->getMode(), false);
1152        setupDrawProgram();
1153        setupDrawDirtyRegionsDisabled();
1154        setupDrawPureColorUniforms();
1155        setupDrawColorFilterUniforms();
1156        setupDrawTexture(layer->getTexture());
1157        if (currentTransform().isPureTranslate()) {
1158            const float x = (int) floorf(rect.left + currentTransform().getTranslateX() + 0.5f);
1159            const float y = (int) floorf(rect.top + currentTransform().getTranslateY() + 0.5f);
1160
1161            layer->setFilter(GL_NEAREST);
1162            setupDrawModelViewTranslate(x, y, x + rect.getWidth(), y + rect.getHeight(), true);
1163        } else {
1164            layer->setFilter(GL_LINEAR);
1165            setupDrawModelViewTranslate(rect.left, rect.top, rect.right, rect.bottom);
1166        }
1167        setupDrawMeshIndices(&mesh[0].position[0], &mesh[0].texture[0]);
1168
1169        for (size_t i = 0; i < count; i++) {
1170            const android::Rect* r = &rects[i];
1171
1172            const float u1 = r->left * texX;
1173            const float v1 = (height - r->top) * texY;
1174            const float u2 = r->right * texX;
1175            const float v2 = (height - r->bottom) * texY;
1176
1177            // TODO: Reject quads outside of the clip
1178            TextureVertex::set(mesh++, r->left, r->top, u1, v1);
1179            TextureVertex::set(mesh++, r->right, r->top, u2, v1);
1180            TextureVertex::set(mesh++, r->left, r->bottom, u1, v2);
1181            TextureVertex::set(mesh++, r->right, r->bottom, u2, v2);
1182
1183            numQuads++;
1184
1185            if (numQuads >= REGION_MESH_QUAD_COUNT) {
1186                DRAW_DOUBLE_STENCIL(glDrawElements(GL_TRIANGLES, numQuads * 6,
1187                                GL_UNSIGNED_SHORT, NULL));
1188                numQuads = 0;
1189                mesh = mCaches.getRegionMesh();
1190            }
1191        }
1192
1193        if (numQuads > 0) {
1194            DRAW_DOUBLE_STENCIL(glDrawElements(GL_TRIANGLES, numQuads * 6,
1195                            GL_UNSIGNED_SHORT, NULL));
1196        }
1197
1198        finishDrawTexture();
1199
1200#if DEBUG_LAYERS_AS_REGIONS
1201        drawRegionRects(layer->region);
1202#endif
1203
1204        layer->region.clear();
1205    }
1206}
1207
1208void OpenGLRenderer::drawRegionRects(const Region& region) {
1209#if DEBUG_LAYERS_AS_REGIONS
1210    size_t count;
1211    const android::Rect* rects = region.getArray(&count);
1212
1213    uint32_t colors[] = {
1214            0x7fff0000, 0x7f00ff00,
1215            0x7f0000ff, 0x7fff00ff,
1216    };
1217
1218    int offset = 0;
1219    int32_t top = rects[0].top;
1220
1221    for (size_t i = 0; i < count; i++) {
1222        if (top != rects[i].top) {
1223            offset ^= 0x2;
1224            top = rects[i].top;
1225        }
1226
1227        Rect r(rects[i].left, rects[i].top, rects[i].right, rects[i].bottom);
1228        drawColorRect(r.left, r.top, r.right, r.bottom, colors[offset + (i & 0x1)],
1229                SkXfermode::kSrcOver_Mode);
1230    }
1231#endif
1232}
1233
1234void OpenGLRenderer::drawRegionRects(const SkRegion& region, int color,
1235        SkXfermode::Mode mode, bool dirty) {
1236    int count = 0;
1237    Vector<float> rects;
1238
1239    SkRegion::Iterator it(region);
1240    while (!it.done()) {
1241        const SkIRect& r = it.rect();
1242        rects.push(r.fLeft);
1243        rects.push(r.fTop);
1244        rects.push(r.fRight);
1245        rects.push(r.fBottom);
1246        count += 4;
1247        it.next();
1248    }
1249
1250    drawColorRects(rects.array(), count, color, mode, true, dirty, false);
1251}
1252
1253void OpenGLRenderer::dirtyLayer(const float left, const float top,
1254        const float right, const float bottom, const mat4 transform) {
1255    if (hasLayer()) {
1256        Rect bounds(left, top, right, bottom);
1257        transform.mapRect(bounds);
1258        dirtyLayerUnchecked(bounds, getRegion());
1259    }
1260}
1261
1262void OpenGLRenderer::dirtyLayer(const float left, const float top,
1263        const float right, const float bottom) {
1264    if (hasLayer()) {
1265        Rect bounds(left, top, right, bottom);
1266        dirtyLayerUnchecked(bounds, getRegion());
1267    }
1268}
1269
1270void OpenGLRenderer::dirtyLayerUnchecked(Rect& bounds, Region* region) {
1271    if (bounds.intersect(*mSnapshot->clipRect)) {
1272        bounds.snapToPixelBoundaries();
1273        android::Rect dirty(bounds.left, bounds.top, bounds.right, bounds.bottom);
1274        if (!dirty.isEmpty()) {
1275            region->orSelf(dirty);
1276        }
1277    }
1278}
1279
1280void OpenGLRenderer::clearLayerRegions() {
1281    const size_t count = mLayers.size();
1282    if (count == 0) return;
1283
1284    if (!mSnapshot->isIgnored()) {
1285        // Doing several glScissor/glClear here can negatively impact
1286        // GPUs with a tiler architecture, instead we draw quads with
1287        // the Clear blending mode
1288
1289        // The list contains bounds that have already been clipped
1290        // against their initial clip rect, and the current clip
1291        // is likely different so we need to disable clipping here
1292        bool scissorChanged = mCaches.disableScissor();
1293
1294        Vertex mesh[count * 6];
1295        Vertex* vertex = mesh;
1296
1297        for (uint32_t i = 0; i < count; i++) {
1298            Rect* bounds = mLayers.itemAt(i);
1299
1300            Vertex::set(vertex++, bounds->left, bounds->bottom);
1301            Vertex::set(vertex++, bounds->left, bounds->top);
1302            Vertex::set(vertex++, bounds->right, bounds->top);
1303            Vertex::set(vertex++, bounds->left, bounds->bottom);
1304            Vertex::set(vertex++, bounds->right, bounds->top);
1305            Vertex::set(vertex++, bounds->right, bounds->bottom);
1306
1307            delete bounds;
1308        }
1309        // We must clear the list of dirty rects before we
1310        // call setupDraw() to prevent stencil setup to do
1311        // the same thing again
1312        mLayers.clear();
1313
1314        setupDraw(false);
1315        setupDrawColor(0.0f, 0.0f, 0.0f, 1.0f);
1316        setupDrawBlending(true, SkXfermode::kClear_Mode);
1317        setupDrawProgram();
1318        setupDrawPureColorUniforms();
1319        setupDrawModelViewTranslate(0.0f, 0.0f, 0.0f, 0.0f, true);
1320        setupDrawVertices(&mesh[0].position[0]);
1321
1322        glDrawArrays(GL_TRIANGLES, 0, count * 6);
1323
1324        if (scissorChanged) mCaches.enableScissor();
1325    } else {
1326        for (uint32_t i = 0; i < count; i++) {
1327            delete mLayers.itemAt(i);
1328        }
1329        mLayers.clear();
1330    }
1331}
1332
1333///////////////////////////////////////////////////////////////////////////////
1334// State Deferral
1335///////////////////////////////////////////////////////////////////////////////
1336
1337bool OpenGLRenderer::storeDisplayState(DeferredDisplayState& state, int stateDeferFlags) {
1338    const Rect& currentClip = *(mSnapshot->clipRect);
1339    const mat4& currentMatrix = *(mSnapshot->transform);
1340
1341    if (stateDeferFlags & kStateDeferFlag_Draw) {
1342        // state has bounds initialized in local coordinates
1343        if (!state.mBounds.isEmpty()) {
1344            currentMatrix.mapRect(state.mBounds);
1345            if (!state.mBounds.intersect(currentClip)) {
1346                // quick rejected
1347                return true;
1348            }
1349        } else {
1350            state.mBounds.set(currentClip);
1351        }
1352    }
1353
1354    state.mClipValid = (stateDeferFlags & kStateDeferFlag_Clip);
1355    if (state.mClipValid) {
1356        state.mClip.set(currentClip);
1357    }
1358
1359    // Transform, drawModifiers, and alpha always deferred, since they are used by state operations
1360    // (Note: saveLayer/restore use colorFilter and alpha, so we just save restore everything)
1361    state.mMatrix.load(currentMatrix);
1362    state.mDrawModifiers = mDrawModifiers;
1363    state.mAlpha = mSnapshot->alpha;
1364    return false;
1365}
1366
1367void OpenGLRenderer::restoreDisplayState(const DeferredDisplayState& state, bool skipClipRestore) {
1368    currentTransform().load(state.mMatrix);
1369    mDrawModifiers = state.mDrawModifiers;
1370    mSnapshot->alpha = state.mAlpha;
1371
1372    if (state.mClipValid && !skipClipRestore) {
1373        mSnapshot->setClip(state.mClip.left, state.mClip.top, state.mClip.right, state.mClip.bottom);
1374        dirtyClip();
1375    }
1376}
1377
1378void OpenGLRenderer::setFullScreenClip() {
1379    mSnapshot->setClip(0, 0, mWidth, mHeight);
1380    dirtyClip();
1381}
1382
1383///////////////////////////////////////////////////////////////////////////////
1384// Transforms
1385///////////////////////////////////////////////////////////////////////////////
1386
1387void OpenGLRenderer::translate(float dx, float dy) {
1388    currentTransform().translate(dx, dy, 0.0f);
1389}
1390
1391void OpenGLRenderer::rotate(float degrees) {
1392    currentTransform().rotate(degrees, 0.0f, 0.0f, 1.0f);
1393}
1394
1395void OpenGLRenderer::scale(float sx, float sy) {
1396    currentTransform().scale(sx, sy, 1.0f);
1397}
1398
1399void OpenGLRenderer::skew(float sx, float sy) {
1400    currentTransform().skew(sx, sy);
1401}
1402
1403void OpenGLRenderer::setMatrix(SkMatrix* matrix) {
1404    if (matrix) {
1405        currentTransform().load(*matrix);
1406    } else {
1407        currentTransform().loadIdentity();
1408    }
1409}
1410
1411bool OpenGLRenderer::hasRectToRectTransform() {
1412    return CC_LIKELY(currentTransform().rectToRect());
1413}
1414
1415void OpenGLRenderer::getMatrix(SkMatrix* matrix) {
1416    currentTransform().copyTo(*matrix);
1417}
1418
1419void OpenGLRenderer::concatMatrix(SkMatrix* matrix) {
1420    SkMatrix transform;
1421    currentTransform().copyTo(transform);
1422    transform.preConcat(*matrix);
1423    currentTransform().load(transform);
1424}
1425
1426///////////////////////////////////////////////////////////////////////////////
1427// Clipping
1428///////////////////////////////////////////////////////////////////////////////
1429
1430void OpenGLRenderer::setScissorFromClip() {
1431    Rect clip(*mSnapshot->clipRect);
1432    clip.snapToPixelBoundaries();
1433
1434    if (mCaches.setScissor(clip.left, mSnapshot->height - clip.bottom,
1435            clip.getWidth(), clip.getHeight())) {
1436        mDirtyClip = false;
1437    }
1438}
1439
1440void OpenGLRenderer::ensureStencilBuffer() {
1441    // Thanks to the mismatch between EGL and OpenGL ES FBO we
1442    // cannot attach a stencil buffer to fbo0 dynamically. Let's
1443    // just hope we have one when hasLayer() returns false.
1444    if (hasLayer()) {
1445        attachStencilBufferToLayer(mSnapshot->layer);
1446    }
1447}
1448
1449void OpenGLRenderer::attachStencilBufferToLayer(Layer* layer) {
1450    // The layer's FBO is already bound when we reach this stage
1451    if (!layer->getStencilRenderBuffer()) {
1452        // GL_QCOM_tiled_rendering doesn't like it if a renderbuffer
1453        // is attached after we initiated tiling. We must turn it off,
1454        // attach the new render buffer then turn tiling back on
1455        endTiling();
1456
1457        RenderBuffer* buffer = mCaches.renderBufferCache.get(
1458                Stencil::getSmallestStencilFormat(), layer->getWidth(), layer->getHeight());
1459        layer->setStencilRenderBuffer(buffer);
1460
1461        startTiling(layer->clipRect, layer->layer.getHeight());
1462    }
1463}
1464
1465void OpenGLRenderer::setStencilFromClip() {
1466    if (!mCaches.debugOverdraw) {
1467        if (!mSnapshot->clipRegion->isEmpty()) {
1468            // NOTE: The order here is important, we must set dirtyClip to false
1469            //       before any draw call to avoid calling back into this method
1470            mDirtyClip = false;
1471
1472            ensureStencilBuffer();
1473
1474            mCaches.stencil.enableWrite();
1475
1476            // Clear the stencil but first make sure we restrict drawing
1477            // to the region's bounds
1478            bool resetScissor = mCaches.enableScissor();
1479            if (resetScissor) {
1480                // The scissor was not set so we now need to update it
1481                setScissorFromClip();
1482            }
1483            mCaches.stencil.clear();
1484            if (resetScissor) mCaches.disableScissor();
1485
1486            // NOTE: We could use the region contour path to generate a smaller mesh
1487            //       Since we are using the stencil we could use the red book path
1488            //       drawing technique. It might increase bandwidth usage though.
1489
1490            // The last parameter is important: we are not drawing in the color buffer
1491            // so we don't want to dirty the current layer, if any
1492            drawRegionRects(*mSnapshot->clipRegion, 0xff000000, SkXfermode::kSrc_Mode, false);
1493
1494            mCaches.stencil.enableTest();
1495
1496            // Draw the region used to generate the stencil if the appropriate debug
1497            // mode is enabled
1498            if (mCaches.debugStencilClip == Caches::kStencilShowRegion) {
1499                drawRegionRects(*mSnapshot->clipRegion, 0x7f0000ff, SkXfermode::kSrcOver_Mode);
1500            }
1501        } else {
1502            mCaches.stencil.disable();
1503        }
1504    }
1505}
1506
1507const Rect& OpenGLRenderer::getClipBounds() {
1508    return mSnapshot->getLocalClip();
1509}
1510
1511bool OpenGLRenderer::quickRejectNoScissor(float left, float top, float right, float bottom) {
1512    if (mSnapshot->isIgnored()) {
1513        return true;
1514    }
1515
1516    Rect r(left, top, right, bottom);
1517    currentTransform().mapRect(r);
1518    r.snapToPixelBoundaries();
1519
1520    Rect clipRect(*mSnapshot->clipRect);
1521    clipRect.snapToPixelBoundaries();
1522
1523    return !clipRect.intersects(r);
1524}
1525
1526bool OpenGLRenderer::quickRejectNoScissor(float left, float top, float right, float bottom,
1527        Rect& transformed, Rect& clip) {
1528    if (mSnapshot->isIgnored()) {
1529        return true;
1530    }
1531
1532    transformed.set(left, top, right, bottom);
1533    currentTransform().mapRect(transformed);
1534    transformed.snapToPixelBoundaries();
1535
1536    clip.set(*mSnapshot->clipRect);
1537    clip.snapToPixelBoundaries();
1538
1539    return !clip.intersects(transformed);
1540}
1541
1542bool OpenGLRenderer::quickRejectPreStroke(float left, float top, float right, float bottom,
1543        SkPaint* paint) {
1544    if (paint->getStyle() != SkPaint::kFill_Style) {
1545        float outset = paint->getStrokeWidth() * 0.5f;
1546        return quickReject(left - outset, top - outset, right + outset, bottom + outset);
1547    } else {
1548        return quickReject(left, top, right, bottom);
1549    }
1550}
1551
1552bool OpenGLRenderer::quickReject(float left, float top, float right, float bottom) {
1553    if (mSnapshot->isIgnored() || bottom <= top || right <= left) {
1554        return true;
1555    }
1556
1557    Rect r(left, top, right, bottom);
1558    currentTransform().mapRect(r);
1559    r.snapToPixelBoundaries();
1560
1561    Rect clipRect(*mSnapshot->clipRect);
1562    clipRect.snapToPixelBoundaries();
1563
1564    bool rejected = !clipRect.intersects(r);
1565    if (!isDeferred() && !rejected) {
1566        mCaches.setScissorEnabled(mScissorOptimizationDisabled || !clipRect.contains(r));
1567    }
1568
1569    return rejected;
1570}
1571
1572void OpenGLRenderer::debugClip() {
1573#if DEBUG_CLIP_REGIONS
1574    if (!isDeferred() && !mSnapshot->clipRegion->isEmpty()) {
1575        drawRegionRects(*mSnapshot->clipRegion, 0x7f00ff00, SkXfermode::kSrcOver_Mode);
1576    }
1577#endif
1578}
1579
1580bool OpenGLRenderer::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {
1581    if (CC_LIKELY(currentTransform().rectToRect())) {
1582        bool clipped = mSnapshot->clip(left, top, right, bottom, op);
1583        if (clipped) {
1584            dirtyClip();
1585        }
1586        return !mSnapshot->clipRect->isEmpty();
1587    }
1588
1589    SkPath path;
1590    path.addRect(left, top, right, bottom);
1591
1592    return clipPath(&path, op);
1593}
1594
1595bool OpenGLRenderer::clipPath(SkPath* path, SkRegion::Op op) {
1596    SkMatrix transform;
1597    currentTransform().copyTo(transform);
1598
1599    SkPath transformed;
1600    path->transform(transform, &transformed);
1601
1602    SkRegion clip;
1603    if (!mSnapshot->clipRegion->isEmpty()) {
1604        clip.setRegion(*mSnapshot->clipRegion);
1605    } else {
1606        Rect* bounds = mSnapshot->clipRect;
1607        clip.setRect(bounds->left, bounds->top, bounds->right, bounds->bottom);
1608    }
1609
1610    SkRegion region;
1611    region.setPath(transformed, clip);
1612
1613    bool clipped = mSnapshot->clipRegionTransformed(region, op);
1614    if (clipped) {
1615        dirtyClip();
1616    }
1617    return !mSnapshot->clipRect->isEmpty();
1618}
1619
1620bool OpenGLRenderer::clipRegion(SkRegion* region, SkRegion::Op op) {
1621    bool clipped = mSnapshot->clipRegionTransformed(*region, op);
1622    if (clipped) {
1623        dirtyClip();
1624    }
1625    return !mSnapshot->clipRect->isEmpty();
1626}
1627
1628Rect* OpenGLRenderer::getClipRect() {
1629    return mSnapshot->clipRect;
1630}
1631
1632///////////////////////////////////////////////////////////////////////////////
1633// Drawing commands
1634///////////////////////////////////////////////////////////////////////////////
1635
1636void OpenGLRenderer::setupDraw(bool clear) {
1637    // TODO: It would be best if we could do this before quickReject()
1638    //       changes the scissor test state
1639    if (clear) clearLayerRegions();
1640    // Make sure setScissor & setStencil happen at the beginning of
1641    // this method
1642    if (mDirtyClip) {
1643        if (mCaches.scissorEnabled) {
1644            setScissorFromClip();
1645        }
1646        setStencilFromClip();
1647    }
1648
1649    mDescription.reset();
1650
1651    mSetShaderColor = false;
1652    mColorSet = false;
1653    mColorA = mColorR = mColorG = mColorB = 0.0f;
1654    mTextureUnit = 0;
1655    mTrackDirtyRegions = true;
1656
1657    // Enable debug highlight when what we're about to draw is tested against
1658    // the stencil buffer and if stencil highlight debugging is on
1659    mDescription.hasDebugHighlight = !mCaches.debugOverdraw &&
1660            mCaches.debugStencilClip == Caches::kStencilShowHighlight &&
1661            mCaches.stencil.isTestEnabled();
1662}
1663
1664void OpenGLRenderer::setupDrawWithTexture(bool isAlpha8) {
1665    mDescription.hasTexture = true;
1666    mDescription.hasAlpha8Texture = isAlpha8;
1667}
1668
1669void OpenGLRenderer::setupDrawWithTextureAndColor(bool isAlpha8) {
1670    mDescription.hasTexture = true;
1671    mDescription.hasColors = true;
1672    mDescription.hasAlpha8Texture = isAlpha8;
1673}
1674
1675void OpenGLRenderer::setupDrawWithExternalTexture() {
1676    mDescription.hasExternalTexture = true;
1677}
1678
1679void OpenGLRenderer::setupDrawNoTexture() {
1680    mCaches.disableTexCoordsVertexArray();
1681}
1682
1683void OpenGLRenderer::setupDrawAA() {
1684    mDescription.isAA = true;
1685}
1686
1687void OpenGLRenderer::setupDrawPoint(float pointSize) {
1688    mDescription.isPoint = true;
1689    mDescription.pointSize = pointSize;
1690}
1691
1692void OpenGLRenderer::setupDrawColor(int color, int alpha) {
1693    mColorA = alpha / 255.0f;
1694    mColorR = mColorA * ((color >> 16) & 0xFF) / 255.0f;
1695    mColorG = mColorA * ((color >>  8) & 0xFF) / 255.0f;
1696    mColorB = mColorA * ((color      ) & 0xFF) / 255.0f;
1697    mColorSet = true;
1698    mSetShaderColor = mDescription.setColor(mColorR, mColorG, mColorB, mColorA);
1699}
1700
1701void OpenGLRenderer::setupDrawAlpha8Color(int color, int alpha) {
1702    mColorA = alpha / 255.0f;
1703    mColorR = mColorA * ((color >> 16) & 0xFF) / 255.0f;
1704    mColorG = mColorA * ((color >>  8) & 0xFF) / 255.0f;
1705    mColorB = mColorA * ((color      ) & 0xFF) / 255.0f;
1706    mColorSet = true;
1707    mSetShaderColor = mDescription.setAlpha8Color(mColorR, mColorG, mColorB, mColorA);
1708}
1709
1710void OpenGLRenderer::setupDrawTextGamma(const SkPaint* paint) {
1711    mCaches.fontRenderer->describe(mDescription, paint);
1712}
1713
1714void OpenGLRenderer::setupDrawColor(float r, float g, float b, float a) {
1715    mColorA = a;
1716    mColorR = r;
1717    mColorG = g;
1718    mColorB = b;
1719    mColorSet = true;
1720    mSetShaderColor = mDescription.setColor(r, g, b, a);
1721}
1722
1723void OpenGLRenderer::setupDrawShader() {
1724    if (mDrawModifiers.mShader) {
1725        mDrawModifiers.mShader->describe(mDescription, mExtensions);
1726    }
1727}
1728
1729void OpenGLRenderer::setupDrawColorFilter() {
1730    if (mDrawModifiers.mColorFilter) {
1731        mDrawModifiers.mColorFilter->describe(mDescription, mExtensions);
1732    }
1733}
1734
1735void OpenGLRenderer::accountForClear(SkXfermode::Mode mode) {
1736    if (mColorSet && mode == SkXfermode::kClear_Mode) {
1737        mColorA = 1.0f;
1738        mColorR = mColorG = mColorB = 0.0f;
1739        mSetShaderColor = mDescription.modulate = true;
1740    }
1741}
1742
1743void OpenGLRenderer::setupDrawBlending(SkXfermode::Mode mode, bool swapSrcDst) {
1744    // When the blending mode is kClear_Mode, we need to use a modulate color
1745    // argb=1,0,0,0
1746    accountForClear(mode);
1747    bool blend = (mColorSet && mColorA < 1.0f) ||
1748            (mDrawModifiers.mShader && mDrawModifiers.mShader->blend());
1749    chooseBlending(blend, mode, mDescription, swapSrcDst);
1750}
1751
1752void OpenGLRenderer::setupDrawBlending(bool blend, SkXfermode::Mode mode, bool swapSrcDst) {
1753    // When the blending mode is kClear_Mode, we need to use a modulate color
1754    // argb=1,0,0,0
1755    accountForClear(mode);
1756    blend |= (mColorSet && mColorA < 1.0f) ||
1757            (mDrawModifiers.mShader && mDrawModifiers.mShader->blend()) ||
1758            (mDrawModifiers.mColorFilter && mDrawModifiers.mColorFilter->blend());
1759    chooseBlending(blend, mode, mDescription, swapSrcDst);
1760}
1761
1762void OpenGLRenderer::setupDrawProgram() {
1763    useProgram(mCaches.programCache.get(mDescription));
1764}
1765
1766void OpenGLRenderer::setupDrawDirtyRegionsDisabled() {
1767    mTrackDirtyRegions = false;
1768}
1769
1770void OpenGLRenderer::setupDrawModelViewTranslate(float left, float top, float right, float bottom,
1771        bool ignoreTransform) {
1772    mModelView.loadTranslate(left, top, 0.0f);
1773    if (!ignoreTransform) {
1774        mCaches.currentProgram->set(mOrthoMatrix, mModelView, currentTransform());
1775        if (mTrackDirtyRegions) dirtyLayer(left, top, right, bottom, currentTransform());
1776    } else {
1777        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mat4::identity());
1778        if (mTrackDirtyRegions) dirtyLayer(left, top, right, bottom);
1779    }
1780}
1781
1782void OpenGLRenderer::setupDrawModelViewIdentity(bool offset) {
1783    mCaches.currentProgram->set(mOrthoMatrix, mat4::identity(), currentTransform(), offset);
1784}
1785
1786void OpenGLRenderer::setupDrawModelView(float left, float top, float right, float bottom,
1787        bool ignoreTransform, bool ignoreModelView) {
1788    if (!ignoreModelView) {
1789        mModelView.loadTranslate(left, top, 0.0f);
1790        mModelView.scale(right - left, bottom - top, 1.0f);
1791    } else {
1792        mModelView.loadIdentity();
1793    }
1794    bool dirty = right - left > 0.0f && bottom - top > 0.0f;
1795    if (!ignoreTransform) {
1796        mCaches.currentProgram->set(mOrthoMatrix, mModelView, currentTransform());
1797        if (mTrackDirtyRegions && dirty) {
1798            dirtyLayer(left, top, right, bottom, currentTransform());
1799        }
1800    } else {
1801        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mat4::identity());
1802        if (mTrackDirtyRegions && dirty) dirtyLayer(left, top, right, bottom);
1803    }
1804}
1805
1806void OpenGLRenderer::setupDrawPointUniforms() {
1807    int slot = mCaches.currentProgram->getUniform("pointSize");
1808    glUniform1f(slot, mDescription.pointSize);
1809}
1810
1811void OpenGLRenderer::setupDrawColorUniforms() {
1812    if ((mColorSet && !mDrawModifiers.mShader) || (mDrawModifiers.mShader && mSetShaderColor)) {
1813        mCaches.currentProgram->setColor(mColorR, mColorG, mColorB, mColorA);
1814    }
1815}
1816
1817void OpenGLRenderer::setupDrawPureColorUniforms() {
1818    if (mSetShaderColor) {
1819        mCaches.currentProgram->setColor(mColorR, mColorG, mColorB, mColorA);
1820    }
1821}
1822
1823void OpenGLRenderer::setupDrawShaderUniforms(bool ignoreTransform) {
1824    if (mDrawModifiers.mShader) {
1825        if (ignoreTransform) {
1826            mModelView.loadInverse(currentTransform());
1827        }
1828        mDrawModifiers.mShader->setupProgram(mCaches.currentProgram,
1829                mModelView, *mSnapshot, &mTextureUnit);
1830    }
1831}
1832
1833void OpenGLRenderer::setupDrawShaderIdentityUniforms() {
1834    if (mDrawModifiers.mShader) {
1835        mDrawModifiers.mShader->setupProgram(mCaches.currentProgram,
1836                mat4::identity(), *mSnapshot, &mTextureUnit);
1837    }
1838}
1839
1840void OpenGLRenderer::setupDrawColorFilterUniforms() {
1841    if (mDrawModifiers.mColorFilter) {
1842        mDrawModifiers.mColorFilter->setupProgram(mCaches.currentProgram);
1843    }
1844}
1845
1846void OpenGLRenderer::setupDrawTextGammaUniforms() {
1847    mCaches.fontRenderer->setupProgram(mDescription, mCaches.currentProgram);
1848}
1849
1850void OpenGLRenderer::setupDrawSimpleMesh() {
1851    bool force = mCaches.bindMeshBuffer();
1852    mCaches.bindPositionVertexPointer(force, 0);
1853    mCaches.unbindIndicesBuffer();
1854}
1855
1856void OpenGLRenderer::setupDrawTexture(GLuint texture) {
1857    if (texture) bindTexture(texture);
1858    mTextureUnit++;
1859    mCaches.enableTexCoordsVertexArray();
1860}
1861
1862void OpenGLRenderer::setupDrawExternalTexture(GLuint texture) {
1863    bindExternalTexture(texture);
1864    mTextureUnit++;
1865    mCaches.enableTexCoordsVertexArray();
1866}
1867
1868void OpenGLRenderer::setupDrawTextureTransform() {
1869    mDescription.hasTextureTransform = true;
1870}
1871
1872void OpenGLRenderer::setupDrawTextureTransformUniforms(mat4& transform) {
1873    glUniformMatrix4fv(mCaches.currentProgram->getUniform("mainTextureTransform"), 1,
1874            GL_FALSE, &transform.data[0]);
1875}
1876
1877void OpenGLRenderer::setupDrawMesh(GLvoid* vertices, GLvoid* texCoords, GLuint vbo) {
1878    bool force = false;
1879    if (!vertices) {
1880        force = mCaches.bindMeshBuffer(vbo == 0 ? mCaches.meshBuffer : vbo);
1881    } else {
1882        force = mCaches.unbindMeshBuffer();
1883    }
1884
1885    mCaches.bindPositionVertexPointer(force, vertices);
1886    if (mCaches.currentProgram->texCoords >= 0) {
1887        mCaches.bindTexCoordsVertexPointer(force, texCoords);
1888    }
1889
1890    mCaches.unbindIndicesBuffer();
1891}
1892
1893void OpenGLRenderer::setupDrawMesh(GLvoid* vertices, GLvoid* texCoords, GLvoid* colors) {
1894    bool force = mCaches.unbindMeshBuffer();
1895    GLsizei stride = sizeof(ColorTextureVertex);
1896
1897    mCaches.bindPositionVertexPointer(force, vertices, stride);
1898    if (mCaches.currentProgram->texCoords >= 0) {
1899        mCaches.bindTexCoordsVertexPointer(force, texCoords, stride);
1900    }
1901    int slot = mCaches.currentProgram->getAttrib("colors");
1902    if (slot >= 0) {
1903        glEnableVertexAttribArray(slot);
1904        glVertexAttribPointer(slot, 4, GL_FLOAT, GL_FALSE, stride, colors);
1905    }
1906
1907    mCaches.unbindIndicesBuffer();
1908}
1909
1910void OpenGLRenderer::setupDrawMeshIndices(GLvoid* vertices, GLvoid* texCoords) {
1911    bool force = mCaches.unbindMeshBuffer();
1912    mCaches.bindPositionVertexPointer(force, vertices);
1913    if (mCaches.currentProgram->texCoords >= 0) {
1914        mCaches.bindTexCoordsVertexPointer(force, texCoords);
1915    }
1916}
1917
1918void OpenGLRenderer::setupDrawVertices(GLvoid* vertices) {
1919    bool force = mCaches.unbindMeshBuffer();
1920    mCaches.bindPositionVertexPointer(force, vertices, gVertexStride);
1921    mCaches.unbindIndicesBuffer();
1922}
1923
1924void OpenGLRenderer::finishDrawTexture() {
1925}
1926
1927///////////////////////////////////////////////////////////////////////////////
1928// Drawing
1929///////////////////////////////////////////////////////////////////////////////
1930
1931status_t OpenGLRenderer::drawDisplayList(DisplayList* displayList, Rect& dirty,
1932        int32_t replayFlags) {
1933    status_t status;
1934    // All the usual checks and setup operations (quickReject, setupDraw, etc.)
1935    // will be performed by the display list itself
1936    if (displayList && displayList->isRenderable()) {
1937        if (CC_UNLIKELY(mCaches.drawDeferDisabled)) {
1938            status = startFrame();
1939            ReplayStateStruct replayStruct(*this, dirty, replayFlags);
1940            displayList->replay(replayStruct, 0);
1941            return status | replayStruct.mDrawGlStatus;
1942        }
1943
1944        DeferredDisplayList deferredList;
1945        DeferStateStruct deferStruct(deferredList, *this, replayFlags);
1946        displayList->defer(deferStruct, 0);
1947
1948        flushLayers();
1949        status = startFrame();
1950
1951        return status | deferredList.flush(*this, dirty);
1952    }
1953
1954    return DrawGlInfo::kStatusDone;
1955}
1956
1957void OpenGLRenderer::outputDisplayList(DisplayList* displayList) {
1958    if (displayList) {
1959        displayList->output(1);
1960    }
1961}
1962
1963void OpenGLRenderer::drawAlphaBitmap(Texture* texture, float left, float top, SkPaint* paint) {
1964    int alpha;
1965    SkXfermode::Mode mode;
1966    getAlphaAndMode(paint, &alpha, &mode);
1967
1968    int color = paint != NULL ? paint->getColor() : 0;
1969
1970    float x = left;
1971    float y = top;
1972
1973    texture->setWrap(GL_CLAMP_TO_EDGE, true);
1974
1975    bool ignoreTransform = false;
1976    if (currentTransform().isPureTranslate()) {
1977        x = (int) floorf(left + currentTransform().getTranslateX() + 0.5f);
1978        y = (int) floorf(top + currentTransform().getTranslateY() + 0.5f);
1979        ignoreTransform = true;
1980
1981        texture->setFilter(GL_NEAREST, true);
1982    } else {
1983        texture->setFilter(FILTER(paint), true);
1984    }
1985
1986    drawAlpha8TextureMesh(x, y, x + texture->width, y + texture->height, texture->id,
1987            paint != NULL, color, alpha, mode, (GLvoid*) NULL,
1988            (GLvoid*) gMeshTextureOffset, GL_TRIANGLE_STRIP, gMeshCount, ignoreTransform);
1989}
1990
1991status_t OpenGLRenderer::drawBitmaps(SkBitmap* bitmap, int bitmapCount, TextureVertex* vertices,
1992        const Rect& bounds, SkPaint* paint) {
1993
1994    // merged draw operations don't need scissor, but clip should still be valid
1995    mCaches.setScissorEnabled(mScissorOptimizationDisabled);
1996
1997    mCaches.activeTexture(0);
1998    Texture* texture = mCaches.textureCache.get(bitmap);
1999    if (!texture) return DrawGlInfo::kStatusDone;
2000    const AutoTexture autoCleanup(texture);
2001
2002    int alpha;
2003    SkXfermode::Mode mode;
2004    getAlphaAndMode(paint, &alpha, &mode);
2005
2006    texture->setWrap(GL_CLAMP_TO_EDGE, true);
2007    texture->setFilter(GL_NEAREST, true); // merged ops are always pure-translation for now
2008
2009    const float x = (int) floorf(bounds.left + 0.5f);
2010    const float y = (int) floorf(bounds.top + 0.5f);
2011    if (CC_UNLIKELY(bitmap->getConfig() == SkBitmap::kA8_Config)) {
2012        int color = paint != NULL ? paint->getColor() : 0;
2013        drawAlpha8TextureMesh(x, y, x + bounds.getWidth(), y + bounds.getHeight(),
2014                texture->id, paint != NULL, color, alpha, mode,
2015                &vertices[0].position[0], &vertices[0].texture[0],
2016                GL_TRIANGLES, bitmapCount * 6, true, true);
2017    } else {
2018        drawTextureMesh(x, y, x + bounds.getWidth(), y + bounds.getHeight(),
2019                texture->id, alpha / 255.0f, mode, texture->blend,
2020                &vertices[0].position[0], &vertices[0].texture[0],
2021                GL_TRIANGLES, bitmapCount * 6, false, true, 0, true);
2022    }
2023
2024    return DrawGlInfo::kStatusDrew;
2025}
2026
2027status_t OpenGLRenderer::drawBitmap(SkBitmap* bitmap, float left, float top, SkPaint* paint) {
2028    const float right = left + bitmap->width();
2029    const float bottom = top + bitmap->height();
2030
2031    if (quickReject(left, top, right, bottom)) {
2032        return DrawGlInfo::kStatusDone;
2033    }
2034
2035    mCaches.activeTexture(0);
2036    Texture* texture = mCaches.textureCache.get(bitmap);
2037    if (!texture) return DrawGlInfo::kStatusDone;
2038    const AutoTexture autoCleanup(texture);
2039
2040    if (CC_UNLIKELY(bitmap->getConfig() == SkBitmap::kA8_Config)) {
2041        drawAlphaBitmap(texture, left, top, paint);
2042    } else {
2043        drawTextureRect(left, top, right, bottom, texture, paint);
2044    }
2045
2046    return DrawGlInfo::kStatusDrew;
2047}
2048
2049status_t OpenGLRenderer::drawBitmap(SkBitmap* bitmap, SkMatrix* matrix, SkPaint* paint) {
2050    Rect r(0.0f, 0.0f, bitmap->width(), bitmap->height());
2051    const mat4 transform(*matrix);
2052    transform.mapRect(r);
2053
2054    if (quickReject(r.left, r.top, r.right, r.bottom)) {
2055        return DrawGlInfo::kStatusDone;
2056    }
2057
2058    mCaches.activeTexture(0);
2059    Texture* texture = mCaches.textureCache.get(bitmap);
2060    if (!texture) return DrawGlInfo::kStatusDone;
2061    const AutoTexture autoCleanup(texture);
2062
2063    // This could be done in a cheaper way, all we need is pass the matrix
2064    // to the vertex shader. The save/restore is a bit overkill.
2065    save(SkCanvas::kMatrix_SaveFlag);
2066    concatMatrix(matrix);
2067    if (CC_UNLIKELY(bitmap->getConfig() == SkBitmap::kA8_Config)) {
2068        drawAlphaBitmap(texture, 0.0f, 0.0f, paint);
2069    } else {
2070        drawTextureRect(0.0f, 0.0f, bitmap->width(), bitmap->height(), texture, paint);
2071    }
2072    restore();
2073
2074    return DrawGlInfo::kStatusDrew;
2075}
2076
2077status_t OpenGLRenderer::drawBitmapData(SkBitmap* bitmap, float left, float top, SkPaint* paint) {
2078    const float right = left + bitmap->width();
2079    const float bottom = top + bitmap->height();
2080
2081    if (quickReject(left, top, right, bottom)) {
2082        return DrawGlInfo::kStatusDone;
2083    }
2084
2085    mCaches.activeTexture(0);
2086    Texture* texture = mCaches.textureCache.getTransient(bitmap);
2087    const AutoTexture autoCleanup(texture);
2088
2089    if (CC_UNLIKELY(bitmap->getConfig() == SkBitmap::kA8_Config)) {
2090        drawAlphaBitmap(texture, left, top, paint);
2091    } else {
2092        drawTextureRect(left, top, right, bottom, texture, paint);
2093    }
2094
2095    return DrawGlInfo::kStatusDrew;
2096}
2097
2098status_t OpenGLRenderer::drawBitmapMesh(SkBitmap* bitmap, int meshWidth, int meshHeight,
2099        float* vertices, int* colors, SkPaint* paint) {
2100    if (!vertices || mSnapshot->isIgnored()) {
2101        return DrawGlInfo::kStatusDone;
2102    }
2103
2104    float left = FLT_MAX;
2105    float top = FLT_MAX;
2106    float right = FLT_MIN;
2107    float bottom = FLT_MIN;
2108
2109    const uint32_t count = meshWidth * meshHeight * 6;
2110
2111    ColorTextureVertex mesh[count];
2112    ColorTextureVertex* vertex = mesh;
2113
2114    bool cleanupColors = false;
2115    if (!colors) {
2116        uint32_t colorsCount = (meshWidth + 1) * (meshHeight + 1);
2117        colors = new int[colorsCount];
2118        memset(colors, 0xff, colorsCount * sizeof(int));
2119        cleanupColors = true;
2120    }
2121
2122    for (int32_t y = 0; y < meshHeight; y++) {
2123        for (int32_t x = 0; x < meshWidth; x++) {
2124            uint32_t i = (y * (meshWidth + 1) + x) * 2;
2125
2126            float u1 = float(x) / meshWidth;
2127            float u2 = float(x + 1) / meshWidth;
2128            float v1 = float(y) / meshHeight;
2129            float v2 = float(y + 1) / meshHeight;
2130
2131            int ax = i + (meshWidth + 1) * 2;
2132            int ay = ax + 1;
2133            int bx = i;
2134            int by = bx + 1;
2135            int cx = i + 2;
2136            int cy = cx + 1;
2137            int dx = i + (meshWidth + 1) * 2 + 2;
2138            int dy = dx + 1;
2139
2140            ColorTextureVertex::set(vertex++, vertices[dx], vertices[dy], u2, v2, colors[dx / 2]);
2141            ColorTextureVertex::set(vertex++, vertices[ax], vertices[ay], u1, v2, colors[ax / 2]);
2142            ColorTextureVertex::set(vertex++, vertices[bx], vertices[by], u1, v1, colors[bx / 2]);
2143
2144            ColorTextureVertex::set(vertex++, vertices[dx], vertices[dy], u2, v2, colors[dx / 2]);
2145            ColorTextureVertex::set(vertex++, vertices[bx], vertices[by], u1, v1, colors[bx / 2]);
2146            ColorTextureVertex::set(vertex++, vertices[cx], vertices[cy], u2, v1, colors[cx / 2]);
2147
2148            left = fminf(left, fminf(vertices[ax], fminf(vertices[bx], vertices[cx])));
2149            top = fminf(top, fminf(vertices[ay], fminf(vertices[by], vertices[cy])));
2150            right = fmaxf(right, fmaxf(vertices[ax], fmaxf(vertices[bx], vertices[cx])));
2151            bottom = fmaxf(bottom, fmaxf(vertices[ay], fmaxf(vertices[by], vertices[cy])));
2152        }
2153    }
2154
2155    if (quickReject(left, top, right, bottom)) {
2156        if (cleanupColors) delete[] colors;
2157        return DrawGlInfo::kStatusDone;
2158    }
2159
2160    mCaches.activeTexture(0);
2161    Texture* texture = mCaches.textureCache.get(bitmap);
2162    if (!texture) {
2163        if (cleanupColors) delete[] colors;
2164        return DrawGlInfo::kStatusDone;
2165    }
2166    const AutoTexture autoCleanup(texture);
2167
2168    texture->setWrap(GL_CLAMP_TO_EDGE, true);
2169    texture->setFilter(FILTER(paint), true);
2170
2171    int alpha;
2172    SkXfermode::Mode mode;
2173    getAlphaAndMode(paint, &alpha, &mode);
2174
2175    float a = alpha / 255.0f;
2176
2177    if (hasLayer()) {
2178        dirtyLayer(left, top, right, bottom, currentTransform());
2179    }
2180
2181    setupDraw();
2182    setupDrawWithTextureAndColor();
2183    setupDrawColor(a, a, a, a);
2184    setupDrawColorFilter();
2185    setupDrawBlending(true, mode, false);
2186    setupDrawProgram();
2187    setupDrawDirtyRegionsDisabled();
2188    setupDrawModelView(0.0f, 0.0f, 1.0f, 1.0f, false);
2189    setupDrawTexture(texture->id);
2190    setupDrawPureColorUniforms();
2191    setupDrawColorFilterUniforms();
2192    setupDrawMesh(&mesh[0].position[0], &mesh[0].texture[0], &mesh[0].color[0]);
2193
2194    glDrawArrays(GL_TRIANGLES, 0, count);
2195
2196    finishDrawTexture();
2197
2198    int slot = mCaches.currentProgram->getAttrib("colors");
2199    if (slot >= 0) {
2200        glDisableVertexAttribArray(slot);
2201    }
2202
2203    if (cleanupColors) delete[] colors;
2204
2205    return DrawGlInfo::kStatusDrew;
2206}
2207
2208status_t OpenGLRenderer::drawBitmap(SkBitmap* bitmap,
2209         float srcLeft, float srcTop, float srcRight, float srcBottom,
2210         float dstLeft, float dstTop, float dstRight, float dstBottom,
2211         SkPaint* paint) {
2212    if (quickReject(dstLeft, dstTop, dstRight, dstBottom)) {
2213        return DrawGlInfo::kStatusDone;
2214    }
2215
2216    mCaches.activeTexture(0);
2217    Texture* texture = mCaches.textureCache.get(bitmap);
2218    if (!texture) return DrawGlInfo::kStatusDone;
2219    const AutoTexture autoCleanup(texture);
2220
2221    const float width = texture->width;
2222    const float height = texture->height;
2223
2224    const float u1 = fmax(0.0f, srcLeft / width);
2225    const float v1 = fmax(0.0f, srcTop / height);
2226    const float u2 = fmin(1.0f, srcRight / width);
2227    const float v2 = fmin(1.0f, srcBottom / height);
2228
2229    mCaches.unbindMeshBuffer();
2230    resetDrawTextureTexCoords(u1, v1, u2, v2);
2231
2232    int alpha;
2233    SkXfermode::Mode mode;
2234    getAlphaAndMode(paint, &alpha, &mode);
2235
2236    texture->setWrap(GL_CLAMP_TO_EDGE, true);
2237
2238    float scaleX = (dstRight - dstLeft) / (srcRight - srcLeft);
2239    float scaleY = (dstBottom - dstTop) / (srcBottom - srcTop);
2240
2241    bool scaled = scaleX != 1.0f || scaleY != 1.0f;
2242    // Apply a scale transform on the canvas only when a shader is in use
2243    // Skia handles the ratio between the dst and src rects as a scale factor
2244    // when a shader is set
2245    bool useScaleTransform = mDrawModifiers.mShader && scaled;
2246    bool ignoreTransform = false;
2247
2248    if (CC_LIKELY(currentTransform().isPureTranslate() && !useScaleTransform)) {
2249        float x = (int) floorf(dstLeft + currentTransform().getTranslateX() + 0.5f);
2250        float y = (int) floorf(dstTop + currentTransform().getTranslateY() + 0.5f);
2251
2252        dstRight = x + (dstRight - dstLeft);
2253        dstBottom = y + (dstBottom - dstTop);
2254
2255        dstLeft = x;
2256        dstTop = y;
2257
2258        texture->setFilter(scaled ? FILTER(paint) : GL_NEAREST, true);
2259        ignoreTransform = true;
2260    } else {
2261        texture->setFilter(FILTER(paint), true);
2262    }
2263
2264    if (CC_UNLIKELY(useScaleTransform)) {
2265        save(SkCanvas::kMatrix_SaveFlag);
2266        translate(dstLeft, dstTop);
2267        scale(scaleX, scaleY);
2268
2269        dstLeft = 0.0f;
2270        dstTop = 0.0f;
2271
2272        dstRight = srcRight - srcLeft;
2273        dstBottom = srcBottom - srcTop;
2274    }
2275
2276    if (CC_UNLIKELY(bitmap->getConfig() == SkBitmap::kA8_Config)) {
2277        int color = paint ? paint->getColor() : 0;
2278        drawAlpha8TextureMesh(dstLeft, dstTop, dstRight, dstBottom,
2279                texture->id, paint != NULL, color, alpha, mode,
2280                &mMeshVertices[0].position[0], &mMeshVertices[0].texture[0],
2281                GL_TRIANGLE_STRIP, gMeshCount, ignoreTransform);
2282    } else {
2283        drawTextureMesh(dstLeft, dstTop, dstRight, dstBottom,
2284                texture->id, alpha / 255.0f, mode, texture->blend,
2285                &mMeshVertices[0].position[0], &mMeshVertices[0].texture[0],
2286                GL_TRIANGLE_STRIP, gMeshCount, false, ignoreTransform);
2287    }
2288
2289    if (CC_UNLIKELY(useScaleTransform)) {
2290        restore();
2291    }
2292
2293    resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
2294
2295    return DrawGlInfo::kStatusDrew;
2296}
2297
2298status_t OpenGLRenderer::drawPatch(SkBitmap* bitmap, const int32_t* xDivs, const int32_t* yDivs,
2299        const uint32_t* colors, uint32_t width, uint32_t height, int8_t numColors,
2300        float left, float top, float right, float bottom, SkPaint* paint) {
2301    int alpha;
2302    SkXfermode::Mode mode;
2303    getAlphaAndMode(paint, &alpha, &mode);
2304
2305    return drawPatch(bitmap, xDivs, yDivs, colors, width, height, numColors,
2306            left, top, right, bottom, alpha, mode);
2307}
2308
2309status_t OpenGLRenderer::drawPatch(SkBitmap* bitmap, const int32_t* xDivs, const int32_t* yDivs,
2310        const uint32_t* colors, uint32_t width, uint32_t height, int8_t numColors,
2311        float left, float top, float right, float bottom, int alpha, SkXfermode::Mode mode) {
2312    if (quickReject(left, top, right, bottom)) {
2313        return DrawGlInfo::kStatusDone;
2314    }
2315
2316    alpha *= mSnapshot->alpha;
2317
2318    const Patch* mesh = mCaches.patchCache.get(bitmap->width(), bitmap->height(),
2319            right - left, bottom - top, xDivs, yDivs, colors, width, height, numColors);
2320
2321    if (CC_LIKELY(mesh && mesh->verticesCount > 0)) {
2322        mCaches.activeTexture(0);
2323        Texture* texture = mCaches.textureCache.get(bitmap);
2324        if (!texture) return DrawGlInfo::kStatusDone;
2325        const AutoTexture autoCleanup(texture);
2326        texture->setWrap(GL_CLAMP_TO_EDGE, true);
2327        texture->setFilter(GL_LINEAR, true);
2328
2329        const bool pureTranslate = currentTransform().isPureTranslate();
2330        // Mark the current layer dirty where we are going to draw the patch
2331        if (hasLayer() && mesh->hasEmptyQuads) {
2332            const float offsetX = left + currentTransform().getTranslateX();
2333            const float offsetY = top + currentTransform().getTranslateY();
2334            const size_t count = mesh->quads.size();
2335            for (size_t i = 0; i < count; i++) {
2336                const Rect& bounds = mesh->quads.itemAt(i);
2337                if (CC_LIKELY(pureTranslate)) {
2338                    const float x = (int) floorf(bounds.left + offsetX + 0.5f);
2339                    const float y = (int) floorf(bounds.top + offsetY + 0.5f);
2340                    dirtyLayer(x, y, x + bounds.getWidth(), y + bounds.getHeight());
2341                } else {
2342                    dirtyLayer(left + bounds.left, top + bounds.top,
2343                            left + bounds.right, top + bounds.bottom, currentTransform());
2344                }
2345            }
2346        }
2347
2348        if (CC_LIKELY(pureTranslate)) {
2349            const float x = (int) floorf(left + currentTransform().getTranslateX() + 0.5f);
2350            const float y = (int) floorf(top + currentTransform().getTranslateY() + 0.5f);
2351
2352            drawTextureMesh(x, y, x + right - left, y + bottom - top, texture->id, alpha / 255.0f,
2353                    mode, texture->blend, (GLvoid*) 0, (GLvoid*) gMeshTextureOffset,
2354                    GL_TRIANGLES, mesh->verticesCount, false, true, mesh->meshBuffer,
2355                    true, !mesh->hasEmptyQuads);
2356        } else {
2357            drawTextureMesh(left, top, right, bottom, texture->id, alpha / 255.0f,
2358                    mode, texture->blend, (GLvoid*) 0, (GLvoid*) gMeshTextureOffset,
2359                    GL_TRIANGLES, mesh->verticesCount, false, false, mesh->meshBuffer,
2360                    true, !mesh->hasEmptyQuads);
2361        }
2362    }
2363
2364    return DrawGlInfo::kStatusDrew;
2365}
2366
2367status_t OpenGLRenderer::drawVertexBuffer(const VertexBuffer& vertexBuffer, SkPaint* paint,
2368        bool useOffset) {
2369    if (!vertexBuffer.getSize()) {
2370        // no vertices to draw
2371        return DrawGlInfo::kStatusDone;
2372    }
2373
2374    int color = paint->getColor();
2375    SkXfermode::Mode mode = getXfermode(paint->getXfermode());
2376    bool isAA = paint->isAntiAlias();
2377
2378    setupDraw();
2379    setupDrawNoTexture();
2380    if (isAA) setupDrawAA();
2381    setupDrawColor(color, ((color >> 24) & 0xFF) * mSnapshot->alpha);
2382    setupDrawColorFilter();
2383    setupDrawShader();
2384    setupDrawBlending(isAA, mode);
2385    setupDrawProgram();
2386    setupDrawModelViewIdentity(useOffset);
2387    setupDrawColorUniforms();
2388    setupDrawColorFilterUniforms();
2389    setupDrawShaderIdentityUniforms();
2390
2391    void* vertices = vertexBuffer.getBuffer();
2392    bool force = mCaches.unbindMeshBuffer();
2393    mCaches.bindPositionVertexPointer(true, vertices, isAA ? gAlphaVertexStride : gVertexStride);
2394    mCaches.resetTexCoordsVertexPointer();
2395    mCaches.unbindIndicesBuffer();
2396
2397    int alphaSlot = -1;
2398    if (isAA) {
2399        void* alphaCoords = ((GLbyte*) vertices) + gVertexAlphaOffset;
2400        alphaSlot = mCaches.currentProgram->getAttrib("vtxAlpha");
2401
2402        // TODO: avoid enable/disable in back to back uses of the alpha attribute
2403        glEnableVertexAttribArray(alphaSlot);
2404        glVertexAttribPointer(alphaSlot, 1, GL_FLOAT, GL_FALSE, gAlphaVertexStride, alphaCoords);
2405    }
2406
2407    glDrawArrays(GL_TRIANGLE_STRIP, 0, vertexBuffer.getSize());
2408
2409    if (isAA) {
2410        glDisableVertexAttribArray(alphaSlot);
2411    }
2412
2413    return DrawGlInfo::kStatusDrew;
2414}
2415
2416/**
2417 * Renders a convex path via tessellation. For AA paths, this function uses a similar approach to
2418 * that of AA lines in the drawLines() function.  We expand the convex path by a half pixel in
2419 * screen space in all directions. However, instead of using a fragment shader to compute the
2420 * translucency of the color from its position, we simply use a varying parameter to define how far
2421 * a given pixel is from the edge. For non-AA paths, the expansion and alpha varying are not used.
2422 *
2423 * Doesn't yet support joins, caps, or path effects.
2424 */
2425status_t OpenGLRenderer::drawConvexPath(const SkPath& path, SkPaint* paint) {
2426    VertexBuffer vertexBuffer;
2427    // TODO: try clipping large paths to viewport
2428    PathTessellator::tessellatePath(path, paint, mSnapshot->transform, vertexBuffer);
2429
2430    if (hasLayer()) {
2431        SkRect bounds = path.getBounds();
2432        PathTessellator::expandBoundsForStroke(bounds, paint, false);
2433        dirtyLayer(bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom, currentTransform());
2434    }
2435
2436    return drawVertexBuffer(vertexBuffer, paint);
2437}
2438
2439/**
2440 * We create tristrips for the lines much like shape stroke tessellation, using a per-vertex alpha
2441 * and additional geometry for defining an alpha slope perimeter.
2442 *
2443 * Using GL_LINES can be difficult because the rasterization rules for those lines produces some
2444 * unexpected results, and may vary between hardware devices. Previously we used a varying-base
2445 * in-shader alpha region, but found it to be taxing on some GPUs.
2446 *
2447 * TODO: try using a fixed input buffer for non-capped lines as in text rendering. this may reduce
2448 * memory transfer by removing need for degenerate vertices.
2449 */
2450status_t OpenGLRenderer::drawLines(float* points, int count, SkPaint* paint) {
2451    if (mSnapshot->isIgnored() || count < 4) return DrawGlInfo::kStatusDone;
2452
2453    count &= ~0x3; // round down to nearest four
2454
2455    VertexBuffer buffer;
2456    SkRect bounds;
2457    PathTessellator::tessellateLines(points, count, paint, mSnapshot->transform, bounds, buffer);
2458
2459    if (quickReject(bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom)) {
2460        return DrawGlInfo::kStatusDone;
2461    }
2462
2463    dirtyLayer(bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom, currentTransform());
2464
2465    bool useOffset = !paint->isAntiAlias();
2466    return drawVertexBuffer(buffer, paint, useOffset);
2467}
2468
2469status_t OpenGLRenderer::drawPoints(float* points, int count, SkPaint* paint) {
2470    if (mSnapshot->isIgnored()) return DrawGlInfo::kStatusDone;
2471
2472    // TODO: The paint's cap style defines whether the points are square or circular
2473    // TODO: Handle AA for round points
2474
2475    // A stroke width of 0 has a special meaning in Skia:
2476    // it draws an unscaled 1px point
2477    float strokeWidth = paint->getStrokeWidth();
2478    const bool isHairLine = paint->getStrokeWidth() == 0.0f;
2479    if (isHairLine) {
2480        // Now that we know it's hairline, we can set the effective width, to be used later
2481        strokeWidth = 1.0f;
2482    }
2483    const float halfWidth = strokeWidth / 2;
2484
2485    int alpha;
2486    SkXfermode::Mode mode;
2487    getAlphaAndMode(paint, &alpha, &mode);
2488
2489    int verticesCount = count >> 1;
2490    int generatedVerticesCount = 0;
2491
2492    TextureVertex pointsData[verticesCount];
2493    TextureVertex* vertex = &pointsData[0];
2494
2495    // TODO: We should optimize this method to not generate vertices for points
2496    // that lie outside of the clip.
2497    mCaches.enableScissor();
2498
2499    setupDraw();
2500    setupDrawNoTexture();
2501    setupDrawPoint(strokeWidth);
2502    setupDrawColor(paint->getColor(), alpha);
2503    setupDrawColorFilter();
2504    setupDrawShader();
2505    setupDrawBlending(mode);
2506    setupDrawProgram();
2507    setupDrawModelViewIdentity(true);
2508    setupDrawColorUniforms();
2509    setupDrawColorFilterUniforms();
2510    setupDrawPointUniforms();
2511    setupDrawShaderIdentityUniforms();
2512    setupDrawMesh(vertex);
2513
2514    for (int i = 0; i < count; i += 2) {
2515        TextureVertex::set(vertex++, points[i], points[i + 1], 0.0f, 0.0f);
2516        generatedVerticesCount++;
2517
2518        float left = points[i] - halfWidth;
2519        float right = points[i] + halfWidth;
2520        float top = points[i + 1] - halfWidth;
2521        float bottom = points [i + 1] + halfWidth;
2522
2523        dirtyLayer(left, top, right, bottom, currentTransform());
2524    }
2525
2526    glDrawArrays(GL_POINTS, 0, generatedVerticesCount);
2527
2528    return DrawGlInfo::kStatusDrew;
2529}
2530
2531status_t OpenGLRenderer::drawColor(int color, SkXfermode::Mode mode) {
2532    // No need to check against the clip, we fill the clip region
2533    if (mSnapshot->isIgnored()) return DrawGlInfo::kStatusDone;
2534
2535    Rect& clip(*mSnapshot->clipRect);
2536    clip.snapToPixelBoundaries();
2537
2538    drawColorRect(clip.left, clip.top, clip.right, clip.bottom, color, mode, true);
2539
2540    return DrawGlInfo::kStatusDrew;
2541}
2542
2543status_t OpenGLRenderer::drawShape(float left, float top, const PathTexture* texture,
2544        SkPaint* paint) {
2545    if (!texture) return DrawGlInfo::kStatusDone;
2546    const AutoTexture autoCleanup(texture);
2547
2548    const float x = left + texture->left - texture->offset;
2549    const float y = top + texture->top - texture->offset;
2550
2551    drawPathTexture(texture, x, y, paint);
2552
2553    return DrawGlInfo::kStatusDrew;
2554}
2555
2556status_t OpenGLRenderer::drawRoundRect(float left, float top, float right, float bottom,
2557        float rx, float ry, SkPaint* p) {
2558    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p) ||
2559            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
2560        return DrawGlInfo::kStatusDone;
2561    }
2562
2563    if (p->getPathEffect() != 0) {
2564        mCaches.activeTexture(0);
2565        const PathTexture* texture = mCaches.pathCache.getRoundRect(
2566                right - left, bottom - top, rx, ry, p);
2567        return drawShape(left, top, texture, p);
2568    }
2569
2570    SkPath path;
2571    SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
2572    if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2573        float outset = p->getStrokeWidth() / 2;
2574        rect.outset(outset, outset);
2575        rx += outset;
2576        ry += outset;
2577    }
2578    path.addRoundRect(rect, rx, ry);
2579    return drawConvexPath(path, p);
2580}
2581
2582status_t OpenGLRenderer::drawCircle(float x, float y, float radius, SkPaint* p) {
2583    if (mSnapshot->isIgnored() || quickRejectPreStroke(x - radius, y - radius,
2584            x + radius, y + radius, p) ||
2585            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
2586        return DrawGlInfo::kStatusDone;
2587    }
2588    if (p->getPathEffect() != 0) {
2589        mCaches.activeTexture(0);
2590        const PathTexture* texture = mCaches.pathCache.getCircle(radius, p);
2591        return drawShape(x - radius, y - radius, texture, p);
2592    }
2593
2594    SkPath path;
2595    if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2596        path.addCircle(x, y, radius + p->getStrokeWidth() / 2);
2597    } else {
2598        path.addCircle(x, y, radius);
2599    }
2600    return drawConvexPath(path, p);
2601}
2602
2603status_t OpenGLRenderer::drawOval(float left, float top, float right, float bottom,
2604        SkPaint* p) {
2605    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p) ||
2606            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
2607        return DrawGlInfo::kStatusDone;
2608    }
2609
2610    if (p->getPathEffect() != 0) {
2611        mCaches.activeTexture(0);
2612        const PathTexture* texture = mCaches.pathCache.getOval(right - left, bottom - top, p);
2613        return drawShape(left, top, texture, p);
2614    }
2615
2616    SkPath path;
2617    SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
2618    if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2619        rect.outset(p->getStrokeWidth() / 2, p->getStrokeWidth() / 2);
2620    }
2621    path.addOval(rect);
2622    return drawConvexPath(path, p);
2623}
2624
2625status_t OpenGLRenderer::drawArc(float left, float top, float right, float bottom,
2626        float startAngle, float sweepAngle, bool useCenter, SkPaint* p) {
2627    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p) ||
2628            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
2629        return DrawGlInfo::kStatusDone;
2630    }
2631
2632    if (fabs(sweepAngle) >= 360.0f) {
2633        return drawOval(left, top, right, bottom, p);
2634    }
2635
2636    // TODO: support fills (accounting for concavity if useCenter && sweepAngle > 180)
2637    if (p->getStyle() != SkPaint::kStroke_Style || p->getPathEffect() != 0 || useCenter) {
2638        mCaches.activeTexture(0);
2639        const PathTexture* texture = mCaches.pathCache.getArc(right - left, bottom - top,
2640                startAngle, sweepAngle, useCenter, p);
2641        return drawShape(left, top, texture, p);
2642    }
2643
2644    SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
2645    if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2646        rect.outset(p->getStrokeWidth() / 2, p->getStrokeWidth() / 2);
2647    }
2648
2649    SkPath path;
2650    if (useCenter) {
2651        path.moveTo(rect.centerX(), rect.centerY());
2652    }
2653    path.arcTo(rect, startAngle, sweepAngle, !useCenter);
2654    if (useCenter) {
2655        path.close();
2656    }
2657    return drawConvexPath(path, p);
2658}
2659
2660// See SkPaintDefaults.h
2661#define SkPaintDefaults_MiterLimit SkIntToScalar(4)
2662
2663status_t OpenGLRenderer::drawRect(float left, float top, float right, float bottom, SkPaint* p) {
2664    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p) ||
2665            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
2666        return DrawGlInfo::kStatusDone;
2667    }
2668
2669    if (p->getStyle() != SkPaint::kFill_Style) {
2670        // only fill style is supported by drawConvexPath, since others have to handle joins
2671        if (p->getPathEffect() != 0 || p->getStrokeJoin() != SkPaint::kMiter_Join ||
2672                p->getStrokeMiter() != SkPaintDefaults_MiterLimit) {
2673            mCaches.activeTexture(0);
2674            const PathTexture* texture =
2675                    mCaches.pathCache.getRect(right - left, bottom - top, p);
2676            return drawShape(left, top, texture, p);
2677        }
2678
2679        SkPath path;
2680        SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
2681        if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2682            rect.outset(p->getStrokeWidth() / 2, p->getStrokeWidth() / 2);
2683        }
2684        path.addRect(rect);
2685        return drawConvexPath(path, p);
2686    }
2687
2688    if (p->isAntiAlias() && !currentTransform().isSimple()) {
2689        SkPath path;
2690        path.addRect(left, top, right, bottom);
2691        return drawConvexPath(path, p);
2692    } else {
2693        drawColorRect(left, top, right, bottom, p->getColor(), getXfermode(p->getXfermode()));
2694        return DrawGlInfo::kStatusDrew;
2695    }
2696}
2697
2698void OpenGLRenderer::drawTextShadow(SkPaint* paint, const char* text, int bytesCount, int count,
2699        const float* positions, FontRenderer& fontRenderer, int alpha, SkXfermode::Mode mode,
2700        float x, float y) {
2701    mCaches.activeTexture(0);
2702
2703    // NOTE: The drop shadow will not perform gamma correction
2704    //       if shader-based correction is enabled
2705    mCaches.dropShadowCache.setFontRenderer(fontRenderer);
2706    const ShadowTexture* shadow = mCaches.dropShadowCache.get(
2707            paint, text, bytesCount, count, mDrawModifiers.mShadowRadius, positions);
2708    // If the drop shadow exceeds the max texture size or couldn't be
2709    // allocated, skip drawing
2710    if (!shadow) return;
2711    const AutoTexture autoCleanup(shadow);
2712
2713    const float sx = x - shadow->left + mDrawModifiers.mShadowDx;
2714    const float sy = y - shadow->top + mDrawModifiers.mShadowDy;
2715
2716    const int shadowAlpha = ((mDrawModifiers.mShadowColor >> 24) & 0xFF) * mSnapshot->alpha;
2717    int shadowColor = mDrawModifiers.mShadowColor;
2718    if (mDrawModifiers.mShader) {
2719        shadowColor = 0xffffffff;
2720    }
2721
2722    setupDraw();
2723    setupDrawWithTexture(true);
2724    setupDrawAlpha8Color(shadowColor, shadowAlpha < 255 ? shadowAlpha : alpha);
2725    setupDrawColorFilter();
2726    setupDrawShader();
2727    setupDrawBlending(true, mode);
2728    setupDrawProgram();
2729    setupDrawModelView(sx, sy, sx + shadow->width, sy + shadow->height);
2730    setupDrawTexture(shadow->id);
2731    setupDrawPureColorUniforms();
2732    setupDrawColorFilterUniforms();
2733    setupDrawShaderUniforms();
2734    setupDrawMesh(NULL, (GLvoid*) gMeshTextureOffset);
2735
2736    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
2737}
2738
2739bool OpenGLRenderer::canSkipText(const SkPaint* paint) const {
2740    float alpha = (mDrawModifiers.mHasShadow ? 1.0f : paint->getAlpha()) * mSnapshot->alpha;
2741    return alpha == 0.0f && getXfermode(paint->getXfermode()) == SkXfermode::kSrcOver_Mode;
2742}
2743
2744class TextSetupFunctor: public Functor {
2745public:
2746    TextSetupFunctor(OpenGLRenderer& renderer, float x, float y, bool pureTranslate,
2747            int alpha, SkXfermode::Mode mode, SkPaint* paint): Functor(),
2748            renderer(renderer), x(x), y(y), pureTranslate(pureTranslate),
2749            alpha(alpha), mode(mode), paint(paint) {
2750    }
2751    ~TextSetupFunctor() { }
2752
2753    status_t operator ()(int what, void* data) {
2754        renderer.setupDraw();
2755        renderer.setupDrawTextGamma(paint);
2756        renderer.setupDrawDirtyRegionsDisabled();
2757        renderer.setupDrawWithTexture(true);
2758        renderer.setupDrawAlpha8Color(paint->getColor(), alpha);
2759        renderer.setupDrawColorFilter();
2760        renderer.setupDrawShader();
2761        renderer.setupDrawBlending(true, mode);
2762        renderer.setupDrawProgram();
2763        renderer.setupDrawModelView(x, y, x, y, pureTranslate, true);
2764        // Calling setupDrawTexture with the name 0 will enable the
2765        // uv attributes and increase the texture unit count
2766        // texture binding will be performed by the font renderer as
2767        // needed
2768        renderer.setupDrawTexture(0);
2769        renderer.setupDrawPureColorUniforms();
2770        renderer.setupDrawColorFilterUniforms();
2771        renderer.setupDrawShaderUniforms(pureTranslate);
2772        renderer.setupDrawTextGammaUniforms();
2773
2774        return NO_ERROR;
2775    }
2776
2777    OpenGLRenderer& renderer;
2778    float x;
2779    float y;
2780    bool pureTranslate;
2781    int alpha;
2782    SkXfermode::Mode mode;
2783    SkPaint* paint;
2784};
2785
2786status_t OpenGLRenderer::drawPosText(const char* text, int bytesCount, int count,
2787        const float* positions, SkPaint* paint) {
2788    if (text == NULL || count == 0 || mSnapshot->isIgnored() || canSkipText(paint)) {
2789        return DrawGlInfo::kStatusDone;
2790    }
2791
2792    // NOTE: Skia does not support perspective transform on drawPosText yet
2793    if (!currentTransform().isSimple()) {
2794        return DrawGlInfo::kStatusDone;
2795    }
2796
2797    float x = 0.0f;
2798    float y = 0.0f;
2799    const bool pureTranslate = currentTransform().isPureTranslate();
2800    if (pureTranslate) {
2801        x = (int) floorf(x + currentTransform().getTranslateX() + 0.5f);
2802        y = (int) floorf(y + currentTransform().getTranslateY() + 0.5f);
2803    }
2804
2805    FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
2806    fontRenderer.setFont(paint, mat4::identity());
2807
2808    int alpha;
2809    SkXfermode::Mode mode;
2810    getAlphaAndMode(paint, &alpha, &mode);
2811
2812    if (CC_UNLIKELY(mDrawModifiers.mHasShadow)) {
2813        drawTextShadow(paint, text, bytesCount, count, positions, fontRenderer,
2814                alpha, mode, 0.0f, 0.0f);
2815    }
2816
2817    // Pick the appropriate texture filtering
2818    bool linearFilter = currentTransform().changesBounds();
2819    if (pureTranslate && !linearFilter) {
2820        linearFilter = fabs(y - (int) y) > 0.0f || fabs(x - (int) x) > 0.0f;
2821    }
2822    fontRenderer.setTextureFiltering(linearFilter);
2823
2824    const Rect* clip = pureTranslate ? mSnapshot->clipRect : &mSnapshot->getLocalClip();
2825    Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
2826
2827    const bool hasActiveLayer = hasLayer();
2828
2829    TextSetupFunctor functor(*this, x, y, pureTranslate, alpha, mode, paint);
2830    if (fontRenderer.renderPosText(paint, clip, text, 0, bytesCount, count, x, y,
2831            positions, hasActiveLayer ? &bounds : NULL, &functor)) {
2832        if (hasActiveLayer) {
2833            if (!pureTranslate) {
2834                currentTransform().mapRect(bounds);
2835            }
2836            dirtyLayerUnchecked(bounds, getRegion());
2837        }
2838    }
2839
2840    return DrawGlInfo::kStatusDrew;
2841}
2842
2843mat4 OpenGLRenderer::findBestFontTransform(const mat4& transform) const {
2844    mat4 fontTransform;
2845    if (CC_LIKELY(transform.isPureTranslate())) {
2846        fontTransform = mat4::identity();
2847    } else {
2848        if (CC_UNLIKELY(transform.isPerspective())) {
2849            fontTransform = mat4::identity();
2850        } else {
2851            float sx, sy;
2852            currentTransform().decomposeScale(sx, sy);
2853            fontTransform.loadScale(sx, sy, 1.0f);
2854        }
2855    }
2856    return fontTransform;
2857}
2858
2859status_t OpenGLRenderer::drawText(const char* text, int bytesCount, int count,
2860        float x, float y, const float* positions, SkPaint* paint, float length,
2861        DrawOpMode drawOpMode) {
2862
2863    if (drawOpMode == kDrawOpMode_Immediate &&
2864            (text == NULL || count == 0 || mSnapshot->isIgnored() || canSkipText(paint))) {
2865        return DrawGlInfo::kStatusDone;
2866    }
2867
2868    if (length < 0.0f) length = paint->measureText(text, bytesCount);
2869    switch (paint->getTextAlign()) {
2870        case SkPaint::kCenter_Align:
2871            x -= length / 2.0f;
2872            break;
2873        case SkPaint::kRight_Align:
2874            x -= length;
2875            break;
2876        default:
2877            break;
2878    }
2879
2880    SkPaint::FontMetrics metrics;
2881    paint->getFontMetrics(&metrics, 0.0f);
2882    if (drawOpMode == kDrawOpMode_Immediate) {
2883        if (quickReject(x, y + metrics.fTop, x + length, y + metrics.fBottom)) {
2884            return DrawGlInfo::kStatusDone;
2885        }
2886    } else {
2887        // merged draw operations don't need scissor, but clip should still be valid
2888        mCaches.setScissorEnabled(mScissorOptimizationDisabled);
2889    }
2890
2891    const float oldX = x;
2892    const float oldY = y;
2893
2894    const mat4& transform = currentTransform();
2895    const bool pureTranslate = transform.isPureTranslate();
2896
2897    if (CC_LIKELY(pureTranslate)) {
2898        x = (int) floorf(x + transform.getTranslateX() + 0.5f);
2899        y = (int) floorf(y + transform.getTranslateY() + 0.5f);
2900    }
2901
2902    int alpha;
2903    SkXfermode::Mode mode;
2904    getAlphaAndMode(paint, &alpha, &mode);
2905
2906    FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
2907
2908    if (CC_UNLIKELY(mDrawModifiers.mHasShadow)) {
2909        fontRenderer.setFont(paint, mat4::identity());
2910        drawTextShadow(paint, text, bytesCount, count, positions, fontRenderer,
2911                alpha, mode, oldX, oldY);
2912    }
2913
2914    const bool hasActiveLayer = hasLayer();
2915
2916    // We only pass a partial transform to the font renderer. That partial
2917    // matrix defines how glyphs are rasterized. Typically we want glyphs
2918    // to be rasterized at their final size on screen, which means the partial
2919    // matrix needs to take the scale factor into account.
2920    // When a partial matrix is used to transform glyphs during rasterization,
2921    // the mesh is generated with the inverse transform (in the case of scale,
2922    // the mesh is generated at 1.0 / scale for instance.) This allows us to
2923    // apply the full transform matrix at draw time in the vertex shader.
2924    // Applying the full matrix in the shader is the easiest way to handle
2925    // rotation and perspective and allows us to always generated quads in the
2926    // font renderer which greatly simplifies the code, clipping in particular.
2927    mat4 fontTransform = findBestFontTransform(transform);
2928    fontRenderer.setFont(paint, fontTransform);
2929
2930    // Pick the appropriate texture filtering
2931    bool linearFilter = !pureTranslate || fabs(y - (int) y) > 0.0f || fabs(x - (int) x) > 0.0f;
2932    fontRenderer.setTextureFiltering(linearFilter);
2933
2934    // TODO: Implement better clipping for scaled/rotated text
2935    const Rect* clip = !pureTranslate ? NULL : mSnapshot->clipRect;
2936    Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
2937
2938    bool status;
2939    TextSetupFunctor functor(*this, x, y, pureTranslate, alpha, mode, paint);
2940
2941    // don't call issuedrawcommand, do it at end of batch
2942    bool forceFinish = (drawOpMode != kDrawOpMode_Defer);
2943    if (CC_UNLIKELY(paint->getTextAlign() != SkPaint::kLeft_Align)) {
2944        SkPaint paintCopy(*paint);
2945        paintCopy.setTextAlign(SkPaint::kLeft_Align);
2946        status = fontRenderer.renderPosText(&paintCopy, clip, text, 0, bytesCount, count, x, y,
2947                positions, hasActiveLayer ? &bounds : NULL, &functor, forceFinish);
2948    } else {
2949        status = fontRenderer.renderPosText(paint, clip, text, 0, bytesCount, count, x, y,
2950                positions, hasActiveLayer ? &bounds : NULL, &functor, forceFinish);
2951    }
2952
2953    if ((status || drawOpMode != kDrawOpMode_Immediate) && hasActiveLayer) {
2954        if (!pureTranslate) {
2955            transform.mapRect(bounds);
2956        }
2957        dirtyLayerUnchecked(bounds, getRegion());
2958    }
2959
2960    drawTextDecorations(text, bytesCount, length, oldX, oldY, paint);
2961
2962    return DrawGlInfo::kStatusDrew;
2963}
2964
2965status_t OpenGLRenderer::drawTextOnPath(const char* text, int bytesCount, int count, SkPath* path,
2966        float hOffset, float vOffset, SkPaint* paint) {
2967    if (text == NULL || count == 0 || mSnapshot->isIgnored() || canSkipText(paint)) {
2968        return DrawGlInfo::kStatusDone;
2969    }
2970
2971    FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
2972    fontRenderer.setFont(paint, mat4::identity());
2973    fontRenderer.setTextureFiltering(true);
2974
2975    int alpha;
2976    SkXfermode::Mode mode;
2977    getAlphaAndMode(paint, &alpha, &mode);
2978
2979    setupDraw();
2980    setupDrawTextGamma(paint);
2981    setupDrawDirtyRegionsDisabled();
2982    setupDrawWithTexture(true);
2983    setupDrawAlpha8Color(paint->getColor(), alpha);
2984    setupDrawColorFilter();
2985    setupDrawShader();
2986    setupDrawBlending(true, mode);
2987    setupDrawProgram();
2988    setupDrawModelView(0.0f, 0.0f, 0.0f, 0.0f, false, true);
2989    // Calling setupDrawTexture with the name 0 will enable the
2990    // uv attributes and increase the texture unit count
2991    // texture binding will be performed by the font renderer as
2992    // needed
2993    setupDrawTexture(0);
2994    setupDrawPureColorUniforms();
2995    setupDrawColorFilterUniforms();
2996    setupDrawShaderUniforms(false);
2997    setupDrawTextGammaUniforms();
2998
2999    const Rect* clip = &mSnapshot->getLocalClip();
3000    Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
3001
3002    const bool hasActiveLayer = hasLayer();
3003
3004    if (fontRenderer.renderTextOnPath(paint, clip, text, 0, bytesCount, count, path,
3005            hOffset, vOffset, hasActiveLayer ? &bounds : NULL)) {
3006        if (hasActiveLayer) {
3007            currentTransform().mapRect(bounds);
3008            dirtyLayerUnchecked(bounds, getRegion());
3009        }
3010    }
3011
3012    return DrawGlInfo::kStatusDrew;
3013}
3014
3015status_t OpenGLRenderer::drawPath(SkPath* path, SkPaint* paint) {
3016    if (mSnapshot->isIgnored()) return DrawGlInfo::kStatusDone;
3017
3018    mCaches.activeTexture(0);
3019
3020    const PathTexture* texture = mCaches.pathCache.get(path, paint);
3021    if (!texture) return DrawGlInfo::kStatusDone;
3022    const AutoTexture autoCleanup(texture);
3023
3024    const float x = texture->left - texture->offset;
3025    const float y = texture->top - texture->offset;
3026
3027    drawPathTexture(texture, x, y, paint);
3028
3029    return DrawGlInfo::kStatusDrew;
3030}
3031
3032status_t OpenGLRenderer::drawLayer(Layer* layer, float x, float y) {
3033    if (!layer) {
3034        return DrawGlInfo::kStatusDone;
3035    }
3036
3037    mat4* transform = NULL;
3038    if (layer->isTextureLayer()) {
3039        transform = &layer->getTransform();
3040        if (!transform->isIdentity()) {
3041            save(0);
3042            currentTransform().multiply(*transform);
3043        }
3044    }
3045
3046    Rect transformed;
3047    Rect clip;
3048    const bool rejected = quickRejectNoScissor(x, y,
3049            x + layer->layer.getWidth(), y + layer->layer.getHeight(), transformed, clip);
3050
3051    if (rejected) {
3052        if (transform && !transform->isIdentity()) {
3053            restore();
3054        }
3055        return DrawGlInfo::kStatusDone;
3056    }
3057
3058    updateLayer(layer, true);
3059
3060    mCaches.setScissorEnabled(mScissorOptimizationDisabled || !clip.contains(transformed));
3061    mCaches.activeTexture(0);
3062
3063    if (CC_LIKELY(!layer->region.isEmpty())) {
3064        SkiaColorFilter* oldFilter = mDrawModifiers.mColorFilter;
3065        mDrawModifiers.mColorFilter = layer->getColorFilter();
3066
3067        if (layer->region.isRect()) {
3068            DRAW_DOUBLE_STENCIL_IF(!layer->hasDrawnSinceUpdate,
3069                    composeLayerRect(layer, layer->regionRect));
3070        } else if (layer->mesh) {
3071            const float a = getLayerAlpha(layer);
3072            setupDraw();
3073            setupDrawWithTexture();
3074            setupDrawColor(a, a, a, a);
3075            setupDrawColorFilter();
3076            setupDrawBlending(layer->isBlend() || a < 1.0f, layer->getMode(), false);
3077            setupDrawProgram();
3078            setupDrawPureColorUniforms();
3079            setupDrawColorFilterUniforms();
3080            setupDrawTexture(layer->getTexture());
3081            if (CC_LIKELY(currentTransform().isPureTranslate())) {
3082                int tx = (int) floorf(x + currentTransform().getTranslateX() + 0.5f);
3083                int ty = (int) floorf(y + currentTransform().getTranslateY() + 0.5f);
3084
3085                layer->setFilter(GL_NEAREST);
3086                setupDrawModelViewTranslate(tx, ty,
3087                        tx + layer->layer.getWidth(), ty + layer->layer.getHeight(), true);
3088            } else {
3089                layer->setFilter(GL_LINEAR);
3090                setupDrawModelViewTranslate(x, y,
3091                        x + layer->layer.getWidth(), y + layer->layer.getHeight());
3092            }
3093            setupDrawMesh(&layer->mesh[0].position[0], &layer->mesh[0].texture[0]);
3094
3095            DRAW_DOUBLE_STENCIL_IF(!layer->hasDrawnSinceUpdate,
3096                    glDrawElements(GL_TRIANGLES, layer->meshElementCount,
3097                            GL_UNSIGNED_SHORT, layer->meshIndices));
3098
3099            finishDrawTexture();
3100
3101#if DEBUG_LAYERS_AS_REGIONS
3102            drawRegionRects(layer->region);
3103#endif
3104        }
3105
3106        mDrawModifiers.mColorFilter = oldFilter;
3107
3108        if (layer->debugDrawUpdate) {
3109            layer->debugDrawUpdate = false;
3110            drawColorRect(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight(),
3111                    0x7f00ff00, SkXfermode::kSrcOver_Mode);
3112        }
3113    }
3114    layer->hasDrawnSinceUpdate = true;
3115
3116    if (transform && !transform->isIdentity()) {
3117        restore();
3118    }
3119
3120    return DrawGlInfo::kStatusDrew;
3121}
3122
3123///////////////////////////////////////////////////////////////////////////////
3124// Shaders
3125///////////////////////////////////////////////////////////////////////////////
3126
3127void OpenGLRenderer::resetShader() {
3128    mDrawModifiers.mShader = NULL;
3129}
3130
3131void OpenGLRenderer::setupShader(SkiaShader* shader) {
3132    mDrawModifiers.mShader = shader;
3133    if (mDrawModifiers.mShader) {
3134        mDrawModifiers.mShader->set(&mCaches.textureCache, &mCaches.gradientCache);
3135    }
3136}
3137
3138///////////////////////////////////////////////////////////////////////////////
3139// Color filters
3140///////////////////////////////////////////////////////////////////////////////
3141
3142void OpenGLRenderer::resetColorFilter() {
3143    mDrawModifiers.mColorFilter = NULL;
3144}
3145
3146void OpenGLRenderer::setupColorFilter(SkiaColorFilter* filter) {
3147    mDrawModifiers.mColorFilter = filter;
3148}
3149
3150///////////////////////////////////////////////////////////////////////////////
3151// Drop shadow
3152///////////////////////////////////////////////////////////////////////////////
3153
3154void OpenGLRenderer::resetShadow() {
3155    mDrawModifiers.mHasShadow = false;
3156}
3157
3158void OpenGLRenderer::setupShadow(float radius, float dx, float dy, int color) {
3159    mDrawModifiers.mHasShadow = true;
3160    mDrawModifiers.mShadowRadius = radius;
3161    mDrawModifiers.mShadowDx = dx;
3162    mDrawModifiers.mShadowDy = dy;
3163    mDrawModifiers.mShadowColor = color;
3164}
3165
3166///////////////////////////////////////////////////////////////////////////////
3167// Draw filters
3168///////////////////////////////////////////////////////////////////////////////
3169
3170void OpenGLRenderer::resetPaintFilter() {
3171    // when clearing the PaintFilter, the masks should also be cleared for simple DrawModifier
3172    // comparison, see MergingDrawBatch::canMergeWith
3173    mDrawModifiers.mHasDrawFilter = false;
3174    mDrawModifiers.mPaintFilterClearBits = 0;
3175    mDrawModifiers.mPaintFilterSetBits = 0;
3176}
3177
3178void OpenGLRenderer::setupPaintFilter(int clearBits, int setBits) {
3179    mDrawModifiers.mHasDrawFilter = true;
3180    mDrawModifiers.mPaintFilterClearBits = clearBits & SkPaint::kAllFlags;
3181    mDrawModifiers.mPaintFilterSetBits = setBits & SkPaint::kAllFlags;
3182}
3183
3184SkPaint* OpenGLRenderer::filterPaint(SkPaint* paint) {
3185    if (CC_LIKELY(!mDrawModifiers.mHasDrawFilter || !paint)) {
3186        return paint;
3187    }
3188
3189    uint32_t flags = paint->getFlags();
3190
3191    mFilteredPaint = *paint;
3192    mFilteredPaint.setFlags((flags & ~mDrawModifiers.mPaintFilterClearBits) |
3193            mDrawModifiers.mPaintFilterSetBits);
3194
3195    return &mFilteredPaint;
3196}
3197
3198///////////////////////////////////////////////////////////////////////////////
3199// Drawing implementation
3200///////////////////////////////////////////////////////////////////////////////
3201
3202void OpenGLRenderer::drawPathTexture(const PathTexture* texture,
3203        float x, float y, SkPaint* paint) {
3204    if (quickReject(x, y, x + texture->width, y + texture->height)) {
3205        return;
3206    }
3207
3208    int alpha;
3209    SkXfermode::Mode mode;
3210    getAlphaAndMode(paint, &alpha, &mode);
3211
3212    setupDraw();
3213    setupDrawWithTexture(true);
3214    setupDrawAlpha8Color(paint->getColor(), alpha);
3215    setupDrawColorFilter();
3216    setupDrawShader();
3217    setupDrawBlending(true, mode);
3218    setupDrawProgram();
3219    setupDrawModelView(x, y, x + texture->width, y + texture->height);
3220    setupDrawTexture(texture->id);
3221    setupDrawPureColorUniforms();
3222    setupDrawColorFilterUniforms();
3223    setupDrawShaderUniforms();
3224    setupDrawMesh(NULL, (GLvoid*) gMeshTextureOffset);
3225
3226    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
3227
3228    finishDrawTexture();
3229}
3230
3231// Same values used by Skia
3232#define kStdStrikeThru_Offset   (-6.0f / 21.0f)
3233#define kStdUnderline_Offset    (1.0f / 9.0f)
3234#define kStdUnderline_Thickness (1.0f / 18.0f)
3235
3236void OpenGLRenderer::drawTextDecorations(const char* text, int bytesCount, float length,
3237        float x, float y, SkPaint* paint) {
3238    // Handle underline and strike-through
3239    uint32_t flags = paint->getFlags();
3240    if (flags & (SkPaint::kUnderlineText_Flag | SkPaint::kStrikeThruText_Flag)) {
3241        SkPaint paintCopy(*paint);
3242        float underlineWidth = length;
3243        // If length is > 0.0f, we already measured the text for the text alignment
3244        if (length <= 0.0f) {
3245            underlineWidth = paintCopy.measureText(text, bytesCount);
3246        }
3247
3248        if (CC_LIKELY(underlineWidth > 0.0f)) {
3249            const float textSize = paintCopy.getTextSize();
3250            const float strokeWidth = fmax(textSize * kStdUnderline_Thickness, 1.0f);
3251
3252            const float left = x;
3253            float top = 0.0f;
3254
3255            int linesCount = 0;
3256            if (flags & SkPaint::kUnderlineText_Flag) linesCount++;
3257            if (flags & SkPaint::kStrikeThruText_Flag) linesCount++;
3258
3259            const int pointsCount = 4 * linesCount;
3260            float points[pointsCount];
3261            int currentPoint = 0;
3262
3263            if (flags & SkPaint::kUnderlineText_Flag) {
3264                top = y + textSize * kStdUnderline_Offset;
3265                points[currentPoint++] = left;
3266                points[currentPoint++] = top;
3267                points[currentPoint++] = left + underlineWidth;
3268                points[currentPoint++] = top;
3269            }
3270
3271            if (flags & SkPaint::kStrikeThruText_Flag) {
3272                top = y + textSize * kStdStrikeThru_Offset;
3273                points[currentPoint++] = left;
3274                points[currentPoint++] = top;
3275                points[currentPoint++] = left + underlineWidth;
3276                points[currentPoint++] = top;
3277            }
3278
3279            paintCopy.setStrokeWidth(strokeWidth);
3280
3281            drawLines(&points[0], pointsCount, &paintCopy);
3282        }
3283    }
3284}
3285
3286status_t OpenGLRenderer::drawRects(const float* rects, int count, SkPaint* paint) {
3287    if (mSnapshot->isIgnored()) {
3288        return DrawGlInfo::kStatusDone;
3289    }
3290
3291    int color = paint->getColor();
3292    // If a shader is set, preserve only the alpha
3293    if (mDrawModifiers.mShader) {
3294        color |= 0x00ffffff;
3295    }
3296    SkXfermode::Mode mode = getXfermode(paint->getXfermode());
3297
3298    return drawColorRects(rects, count, color, mode);
3299}
3300
3301status_t OpenGLRenderer::drawColorRects(const float* rects, int count, int color,
3302        SkXfermode::Mode mode, bool ignoreTransform, bool dirty, bool clip) {
3303    if (count == 0) {
3304        return DrawGlInfo::kStatusDone;
3305    }
3306
3307    float left = FLT_MAX;
3308    float top = FLT_MAX;
3309    float right = FLT_MIN;
3310    float bottom = FLT_MIN;
3311
3312    int vertexCount = 0;
3313    Vertex mesh[count * 6];
3314    Vertex* vertex = mesh;
3315
3316    for (int index = 0; index < count; index += 4) {
3317        float l = rects[index + 0];
3318        float t = rects[index + 1];
3319        float r = rects[index + 2];
3320        float b = rects[index + 3];
3321
3322        Vertex::set(vertex++, l, b);
3323        Vertex::set(vertex++, l, t);
3324        Vertex::set(vertex++, r, t);
3325        Vertex::set(vertex++, l, b);
3326        Vertex::set(vertex++, r, t);
3327        Vertex::set(vertex++, r, b);
3328
3329        vertexCount += 6;
3330
3331        left = fminf(left, l);
3332        top = fminf(top, t);
3333        right = fmaxf(right, r);
3334        bottom = fmaxf(bottom, b);
3335    }
3336
3337    if (clip && quickReject(left, top, right, bottom)) {
3338        return DrawGlInfo::kStatusDone;
3339    }
3340
3341    setupDraw();
3342    setupDrawNoTexture();
3343    setupDrawColor(color, ((color >> 24) & 0xFF) * mSnapshot->alpha);
3344    setupDrawShader();
3345    setupDrawColorFilter();
3346    setupDrawBlending(mode);
3347    setupDrawProgram();
3348    setupDrawDirtyRegionsDisabled();
3349    setupDrawModelView(0.0f, 0.0f, 1.0f, 1.0f, ignoreTransform, true);
3350    setupDrawColorUniforms();
3351    setupDrawShaderUniforms();
3352    setupDrawColorFilterUniforms();
3353    setupDrawVertices((GLvoid*) &mesh[0].position[0]);
3354
3355    if (dirty && hasLayer()) {
3356        dirtyLayer(left, top, right, bottom, currentTransform());
3357    }
3358
3359    glDrawArrays(GL_TRIANGLES, 0, vertexCount);
3360
3361    return DrawGlInfo::kStatusDrew;
3362}
3363
3364void OpenGLRenderer::drawColorRect(float left, float top, float right, float bottom,
3365        int color, SkXfermode::Mode mode, bool ignoreTransform) {
3366    // If a shader is set, preserve only the alpha
3367    if (mDrawModifiers.mShader) {
3368        color |= 0x00ffffff;
3369    }
3370
3371    setupDraw();
3372    setupDrawNoTexture();
3373    setupDrawColor(color, ((color >> 24) & 0xFF) * mSnapshot->alpha);
3374    setupDrawShader();
3375    setupDrawColorFilter();
3376    setupDrawBlending(mode);
3377    setupDrawProgram();
3378    setupDrawModelView(left, top, right, bottom, ignoreTransform);
3379    setupDrawColorUniforms();
3380    setupDrawShaderUniforms(ignoreTransform);
3381    setupDrawColorFilterUniforms();
3382    setupDrawSimpleMesh();
3383
3384    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
3385}
3386
3387void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom,
3388        Texture* texture, SkPaint* paint) {
3389    int alpha;
3390    SkXfermode::Mode mode;
3391    getAlphaAndMode(paint, &alpha, &mode);
3392
3393    texture->setWrap(GL_CLAMP_TO_EDGE, true);
3394
3395    if (CC_LIKELY(currentTransform().isPureTranslate())) {
3396        const float x = (int) floorf(left + currentTransform().getTranslateX() + 0.5f);
3397        const float y = (int) floorf(top + currentTransform().getTranslateY() + 0.5f);
3398
3399        texture->setFilter(GL_NEAREST, true);
3400        drawTextureMesh(x, y, x + texture->width, y + texture->height, texture->id,
3401                alpha / 255.0f, mode, texture->blend, (GLvoid*) NULL,
3402                (GLvoid*) gMeshTextureOffset, GL_TRIANGLE_STRIP, gMeshCount, false, true);
3403    } else {
3404        texture->setFilter(FILTER(paint), true);
3405        drawTextureMesh(left, top, right, bottom, texture->id, alpha / 255.0f, mode,
3406                texture->blend, (GLvoid*) NULL, (GLvoid*) gMeshTextureOffset,
3407                GL_TRIANGLE_STRIP, gMeshCount);
3408    }
3409}
3410
3411void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom,
3412        GLuint texture, float alpha, SkXfermode::Mode mode, bool blend) {
3413    drawTextureMesh(left, top, right, bottom, texture, alpha, mode, blend,
3414            (GLvoid*) NULL, (GLvoid*) gMeshTextureOffset, GL_TRIANGLE_STRIP, gMeshCount);
3415}
3416
3417void OpenGLRenderer::drawTextureMesh(float left, float top, float right, float bottom,
3418        GLuint texture, float alpha, SkXfermode::Mode mode, bool blend,
3419        GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
3420        bool swapSrcDst, bool ignoreTransform, GLuint vbo, bool ignoreScale, bool dirty) {
3421
3422    setupDraw();
3423    setupDrawWithTexture();
3424    setupDrawColor(alpha, alpha, alpha, alpha);
3425    setupDrawColorFilter();
3426    setupDrawBlending(blend, mode, swapSrcDst);
3427    setupDrawProgram();
3428    if (!dirty) setupDrawDirtyRegionsDisabled();
3429    if (!ignoreScale) {
3430        setupDrawModelView(left, top, right, bottom, ignoreTransform);
3431    } else {
3432        setupDrawModelViewTranslate(left, top, right, bottom, ignoreTransform);
3433    }
3434    setupDrawTexture(texture);
3435    setupDrawPureColorUniforms();
3436    setupDrawColorFilterUniforms();
3437    setupDrawMesh(vertices, texCoords, vbo);
3438
3439    glDrawArrays(drawMode, 0, elementsCount);
3440
3441    finishDrawTexture();
3442}
3443
3444void OpenGLRenderer::drawAlpha8TextureMesh(float left, float top, float right, float bottom,
3445        GLuint texture, bool hasColor, int color, int alpha, SkXfermode::Mode mode,
3446        GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
3447        bool ignoreTransform, bool ignoreScale, bool dirty) {
3448
3449    setupDraw();
3450    setupDrawWithTexture(true);
3451    if (hasColor) {
3452        setupDrawAlpha8Color(color, alpha);
3453    }
3454    setupDrawColorFilter();
3455    setupDrawShader();
3456    setupDrawBlending(true, mode);
3457    setupDrawProgram();
3458    if (!dirty) setupDrawDirtyRegionsDisabled();
3459    if (!ignoreScale) {
3460        setupDrawModelView(left, top, right, bottom, ignoreTransform);
3461    } else {
3462        setupDrawModelViewTranslate(left, top, right, bottom, ignoreTransform);
3463    }
3464    setupDrawTexture(texture);
3465    setupDrawPureColorUniforms();
3466    setupDrawColorFilterUniforms();
3467    setupDrawShaderUniforms();
3468    setupDrawMesh(vertices, texCoords);
3469
3470    glDrawArrays(drawMode, 0, elementsCount);
3471
3472    finishDrawTexture();
3473}
3474
3475void OpenGLRenderer::chooseBlending(bool blend, SkXfermode::Mode mode,
3476        ProgramDescription& description, bool swapSrcDst) {
3477    blend = blend || mode != SkXfermode::kSrcOver_Mode;
3478
3479    if (blend) {
3480        // These blend modes are not supported by OpenGL directly and have
3481        // to be implemented using shaders. Since the shader will perform
3482        // the blending, turn blending off here
3483        // If the blend mode cannot be implemented using shaders, fall
3484        // back to the default SrcOver blend mode instead
3485        if (CC_UNLIKELY(mode > SkXfermode::kScreen_Mode)) {
3486            if (CC_UNLIKELY(mExtensions.hasFramebufferFetch())) {
3487                description.framebufferMode = mode;
3488                description.swapSrcDst = swapSrcDst;
3489
3490                if (mCaches.blend) {
3491                    glDisable(GL_BLEND);
3492                    mCaches.blend = false;
3493                }
3494
3495                return;
3496            } else {
3497                mode = SkXfermode::kSrcOver_Mode;
3498            }
3499        }
3500
3501        if (!mCaches.blend) {
3502            glEnable(GL_BLEND);
3503        }
3504
3505        GLenum sourceMode = swapSrcDst ? gBlendsSwap[mode].src : gBlends[mode].src;
3506        GLenum destMode = swapSrcDst ? gBlendsSwap[mode].dst : gBlends[mode].dst;
3507
3508        if (sourceMode != mCaches.lastSrcMode || destMode != mCaches.lastDstMode) {
3509            glBlendFunc(sourceMode, destMode);
3510            mCaches.lastSrcMode = sourceMode;
3511            mCaches.lastDstMode = destMode;
3512        }
3513    } else if (mCaches.blend) {
3514        glDisable(GL_BLEND);
3515    }
3516    mCaches.blend = blend;
3517}
3518
3519bool OpenGLRenderer::useProgram(Program* program) {
3520    if (!program->isInUse()) {
3521        if (mCaches.currentProgram != NULL) mCaches.currentProgram->remove();
3522        program->use();
3523        mCaches.currentProgram = program;
3524        return false;
3525    }
3526    return true;
3527}
3528
3529void OpenGLRenderer::resetDrawTextureTexCoords(float u1, float v1, float u2, float v2) {
3530    TextureVertex* v = &mMeshVertices[0];
3531    TextureVertex::setUV(v++, u1, v1);
3532    TextureVertex::setUV(v++, u2, v1);
3533    TextureVertex::setUV(v++, u1, v2);
3534    TextureVertex::setUV(v++, u2, v2);
3535}
3536
3537void OpenGLRenderer::getAlphaAndMode(SkPaint* paint, int* alpha, SkXfermode::Mode* mode) const {
3538    getAlphaAndModeDirect(paint, alpha,  mode);
3539    if (mDrawModifiers.mOverrideLayerAlpha < 1.0f) {
3540        // if drawing a layer, ignore the paint's alpha
3541        *alpha = mDrawModifiers.mOverrideLayerAlpha * 255;
3542    }
3543    *alpha *= mSnapshot->alpha;
3544}
3545
3546float OpenGLRenderer::getLayerAlpha(Layer* layer) const {
3547    float alpha;
3548    if (mDrawModifiers.mOverrideLayerAlpha < 1.0f) {
3549        alpha = mDrawModifiers.mOverrideLayerAlpha;
3550    } else {
3551        alpha = layer->getAlpha() / 255.0f;
3552    }
3553    return alpha * mSnapshot->alpha;
3554}
3555
3556}; // namespace uirenderer
3557}; // namespace android
3558