OpenGLRenderer.cpp revision 44eb2c00861098dd3e2950d923646814b4cc57c2 
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 "OpenGLRenderer.h"
20
21#include "DeferredDisplayList.h"
22#include "DisplayListRenderer.h"
23#include "Fence.h"
24#include "GammaFontRenderer.h"
25#include "Patch.h"
26#include "PathTessellator.h"
27#include "Properties.h"
28#include "RenderNode.h"
29#include "renderstate/RenderState.h"
30#include "ShadowTessellator.h"
31#include "SkiaShader.h"
32#include "Vector.h"
33#include "VertexBuffer.h"
34#include "utils/GLUtils.h"
35#include "utils/PaintUtils.h"
36#include "utils/TraceUtils.h"
37
38#include <stdlib.h>
39#include <stdint.h>
40#include <sys/types.h>
41
42#include <SkCanvas.h>
43#include <SkColor.h>
44#include <SkShader.h>
45#include <SkTypeface.h>
46
47#include <utils/Log.h>
48#include <utils/StopWatch.h>
49
50#include <private/hwui/DrawGlInfo.h>
51
52#include <ui/Rect.h>
53
54#if DEBUG_DETAILED_EVENTS
55    #define EVENT_LOGD(...) eventMarkDEBUG(__VA_ARGS__)
56#else
57    #define EVENT_LOGD(...)
58#endif
59
60namespace android {
61namespace uirenderer {
62
63static GLenum getFilter(const SkPaint* paint) {
64    if (!paint || paint->getFilterLevel() != SkPaint::kNone_FilterLevel) {
65        return GL_LINEAR;
66    }
67    return GL_NEAREST;
68}
69
70///////////////////////////////////////////////////////////////////////////////
71// Globals
72///////////////////////////////////////////////////////////////////////////////
73
74
75///////////////////////////////////////////////////////////////////////////////
76// Functions
77///////////////////////////////////////////////////////////////////////////////
78
79template<typename T>
80static inline T min(T a, T b) {
81    return a < b ? a : b;
82}
83
84///////////////////////////////////////////////////////////////////////////////
85// Constructors/destructor
86///////////////////////////////////////////////////////////////////////////////
87
88OpenGLRenderer::OpenGLRenderer(RenderState& renderState)
89        : mState(*this)
90        , mCaches(Caches::getInstance())
91        , mExtensions(Extensions::getInstance())
92        , mRenderState(renderState)
93        , mFrameStarted(false)
94        , mScissorOptimizationDisabled(false)
95        , mSuppressTiling(false)
96        , mFirstFrameAfterResize(true)
97        , mDirty(false)
98        , mLightCenter((Vector3){FLT_MIN, FLT_MIN, FLT_MIN})
99        , mLightRadius(FLT_MIN)
100        , mAmbientShadowAlpha(0)
101        , mSpotShadowAlpha(0) {
102    // *set* draw modifiers to be 0
103    memset(&mDrawModifiers, 0, sizeof(mDrawModifiers));
104    mDrawModifiers.mOverrideLayerAlpha = 1.0f;
105
106    memcpy(mMeshVertices, kMeshVertices, sizeof(kMeshVertices));
107}
108
109OpenGLRenderer::~OpenGLRenderer() {
110    // The context has already been destroyed at this point, do not call
111    // GL APIs. All GL state should be kept in Caches.h
112}
113
114void OpenGLRenderer::initProperties() {
115    char property[PROPERTY_VALUE_MAX];
116    if (property_get(PROPERTY_DISABLE_SCISSOR_OPTIMIZATION, property, "false")) {
117        mScissorOptimizationDisabled = !strcasecmp(property, "true");
118        INIT_LOGD("  Scissor optimization %s",
119                mScissorOptimizationDisabled ? "disabled" : "enabled");
120    } else {
121        INIT_LOGD("  Scissor optimization enabled");
122    }
123}
124
125void OpenGLRenderer::initLight(const Vector3& lightCenter, float lightRadius,
126        uint8_t ambientShadowAlpha, uint8_t spotShadowAlpha) {
127    mLightCenter = lightCenter;
128    mLightRadius = lightRadius;
129    mAmbientShadowAlpha = ambientShadowAlpha;
130    mSpotShadowAlpha = spotShadowAlpha;
131}
132
133///////////////////////////////////////////////////////////////////////////////
134// Setup
135///////////////////////////////////////////////////////////////////////////////
136
137void OpenGLRenderer::onViewportInitialized() {
138    glDisable(GL_DITHER);
139    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
140
141    glEnableVertexAttribArray(Program::kBindingPosition);
142    mFirstFrameAfterResize = true;
143}
144
145void OpenGLRenderer::setupFrameState(float left, float top,
146        float right, float bottom, bool opaque) {
147    mCaches.clearGarbage();
148    mState.initializeSaveStack(left, top, right, bottom, mLightCenter);
149    mOpaque = opaque;
150    mTilingClip.set(left, top, right, bottom);
151}
152
153void OpenGLRenderer::startFrame() {
154    if (mFrameStarted) return;
155    mFrameStarted = true;
156
157    mState.setDirtyClip(true);
158
159    discardFramebuffer(mTilingClip.left, mTilingClip.top, mTilingClip.right, mTilingClip.bottom);
160
161    mRenderState.setViewport(mState.getWidth(), mState.getHeight());
162
163    // Functors break the tiling extension in pretty spectacular ways
164    // This ensures we don't use tiling when a functor is going to be
165    // invoked during the frame
166    mSuppressTiling = mCaches.hasRegisteredFunctors()
167            || mFirstFrameAfterResize;
168    mFirstFrameAfterResize = false;
169
170    startTilingCurrentClip(true);
171
172    debugOverdraw(true, true);
173
174    clear(mTilingClip.left, mTilingClip.top,
175            mTilingClip.right, mTilingClip.bottom, mOpaque);
176}
177
178void OpenGLRenderer::prepareDirty(float left, float top,
179        float right, float bottom, bool opaque) {
180
181    setupFrameState(left, top, right, bottom, opaque);
182
183    // Layer renderers will start the frame immediately
184    // The framebuffer renderer will first defer the display list
185    // for each layer and wait until the first drawing command
186    // to start the frame
187    if (currentSnapshot()->fbo == 0) {
188        mRenderState.blend().syncEnabled();
189        updateLayers();
190    } else {
191        startFrame();
192    }
193}
194
195void OpenGLRenderer::discardFramebuffer(float left, float top, float right, float bottom) {
196    // If we know that we are going to redraw the entire framebuffer,
197    // perform a discard to let the driver know we don't need to preserve
198    // the back buffer for this frame.
199    if (mExtensions.hasDiscardFramebuffer() &&
200            left <= 0.0f && top <= 0.0f && right >= mState.getWidth() && bottom >= mState.getHeight()) {
201        const bool isFbo = onGetTargetFbo() == 0;
202        const GLenum attachments[] = {
203                isFbo ? (const GLenum) GL_COLOR_EXT : (const GLenum) GL_COLOR_ATTACHMENT0,
204                isFbo ? (const GLenum) GL_STENCIL_EXT : (const GLenum) GL_STENCIL_ATTACHMENT };
205        glDiscardFramebufferEXT(GL_FRAMEBUFFER, 1, attachments);
206    }
207}
208
209void OpenGLRenderer::clear(float left, float top, float right, float bottom, bool opaque) {
210    if (!opaque) {
211        mRenderState.scissor().setEnabled(true);
212        mRenderState.scissor().set(left, getViewportHeight() - bottom, right - left, bottom - top);
213        glClear(GL_COLOR_BUFFER_BIT);
214        mDirty = true;
215        return;
216    }
217
218    mRenderState.scissor().reset();
219}
220
221void OpenGLRenderer::startTilingCurrentClip(bool opaque, bool expand) {
222    if (!mSuppressTiling) {
223        const Snapshot* snapshot = currentSnapshot();
224
225        const Rect* clip = &mTilingClip;
226        if (snapshot->flags & Snapshot::kFlagFboTarget) {
227            clip = &(snapshot->layer->clipRect);
228        }
229
230        startTiling(*clip, getViewportHeight(), opaque, expand);
231    }
232}
233
234void OpenGLRenderer::startTiling(const Rect& clip, int windowHeight, bool opaque, bool expand) {
235    if (!mSuppressTiling) {
236        if(expand) {
237            // Expand the startTiling region by 1
238            int leftNotZero = (clip.left > 0) ? 1 : 0;
239            int topNotZero = (windowHeight - clip.bottom > 0) ? 1 : 0;
240
241            mCaches.startTiling(
242                clip.left - leftNotZero,
243                windowHeight - clip.bottom - topNotZero,
244                clip.right - clip.left + leftNotZero + 1,
245                clip.bottom - clip.top + topNotZero + 1,
246                opaque);
247        } else {
248            mCaches.startTiling(clip.left, windowHeight - clip.bottom,
249                clip.right - clip.left, clip.bottom - clip.top, opaque);
250        }
251    }
252}
253
254void OpenGLRenderer::endTiling() {
255    if (!mSuppressTiling) mCaches.endTiling();
256}
257
258bool OpenGLRenderer::finish() {
259    renderOverdraw();
260    endTiling();
261    mTempPaths.clear();
262
263    // When finish() is invoked on FBO 0 we've reached the end
264    // of the current frame
265    if (onGetTargetFbo() == 0) {
266        mCaches.pathCache.trim();
267        mCaches.tessellationCache.trim();
268    }
269
270    if (!suppressErrorChecks()) {
271#if DEBUG_OPENGL
272        GLUtils::dumpGLErrors();
273#endif
274
275#if DEBUG_MEMORY_USAGE
276        mCaches.dumpMemoryUsage();
277#else
278        if (mCaches.getDebugLevel() & kDebugMemory) {
279            mCaches.dumpMemoryUsage();
280        }
281#endif
282    }
283
284    mFrameStarted = false;
285
286    return reportAndClearDirty();
287}
288
289void OpenGLRenderer::resumeAfterLayer() {
290    mRenderState.setViewport(getViewportWidth(), getViewportHeight());
291    mRenderState.bindFramebuffer(currentSnapshot()->fbo);
292    debugOverdraw(true, false);
293
294    mRenderState.scissor().reset();
295    dirtyClip();
296}
297
298void OpenGLRenderer::callDrawGLFunction(Functor* functor, Rect& dirty) {
299    if (mState.currentlyIgnored()) return;
300
301    Rect clip(mState.currentClipRect());
302    clip.snapToPixelBoundaries();
303
304    // Since we don't know what the functor will draw, let's dirty
305    // the entire clip region
306    if (hasLayer()) {
307        dirtyLayerUnchecked(clip, getRegion());
308    }
309
310    DrawGlInfo info;
311    info.clipLeft = clip.left;
312    info.clipTop = clip.top;
313    info.clipRight = clip.right;
314    info.clipBottom = clip.bottom;
315    info.isLayer = hasLayer();
316    info.width = getViewportWidth();
317    info.height = getViewportHeight();
318    currentTransform()->copyTo(&info.transform[0]);
319
320    bool prevDirtyClip = mState.getDirtyClip();
321    // setup GL state for functor
322    if (mState.getDirtyClip()) {
323        setStencilFromClip(); // can issue draws, so must precede enableScissor()/interrupt()
324    }
325    if (mRenderState.scissor().setEnabled(true) || prevDirtyClip) {
326        setScissorFromClip();
327    }
328
329    mRenderState.invokeFunctor(functor, DrawGlInfo::kModeDraw, &info);
330    // Scissor may have been modified, reset dirty clip
331    dirtyClip();
332
333    mDirty = true;
334}
335
336///////////////////////////////////////////////////////////////////////////////
337// Debug
338///////////////////////////////////////////////////////////////////////////////
339
340void OpenGLRenderer::eventMarkDEBUG(const char* fmt, ...) const {
341#if DEBUG_DETAILED_EVENTS
342    const int BUFFER_SIZE = 256;
343    va_list ap;
344    char buf[BUFFER_SIZE];
345
346    va_start(ap, fmt);
347    vsnprintf(buf, BUFFER_SIZE, fmt, ap);
348    va_end(ap);
349
350    eventMark(buf);
351#endif
352}
353
354
355void OpenGLRenderer::eventMark(const char* name) const {
356    mCaches.eventMark(0, name);
357}
358
359void OpenGLRenderer::startMark(const char* name) const {
360    mCaches.startMark(0, name);
361}
362
363void OpenGLRenderer::endMark() const {
364    mCaches.endMark();
365}
366
367void OpenGLRenderer::debugOverdraw(bool enable, bool clear) {
368    mRenderState.debugOverdraw(enable, clear);
369}
370
371void OpenGLRenderer::renderOverdraw() {
372    if (mCaches.debugOverdraw && onGetTargetFbo() == 0) {
373        const Rect* clip = &mTilingClip;
374
375        mRenderState.scissor().setEnabled(true);
376        mRenderState.scissor().set(clip->left,
377                mState.firstSnapshot()->getViewportHeight() - clip->bottom,
378                clip->right - clip->left,
379                clip->bottom - clip->top);
380
381        // 1x overdraw
382        mRenderState.stencil().enableDebugTest(2);
383        drawColor(mCaches.getOverdrawColor(1), SkXfermode::kSrcOver_Mode);
384
385        // 2x overdraw
386        mRenderState.stencil().enableDebugTest(3);
387        drawColor(mCaches.getOverdrawColor(2), SkXfermode::kSrcOver_Mode);
388
389        // 3x overdraw
390        mRenderState.stencil().enableDebugTest(4);
391        drawColor(mCaches.getOverdrawColor(3), SkXfermode::kSrcOver_Mode);
392
393        // 4x overdraw and higher
394        mRenderState.stencil().enableDebugTest(4, true);
395        drawColor(mCaches.getOverdrawColor(4), SkXfermode::kSrcOver_Mode);
396
397        mRenderState.stencil().disable();
398    }
399}
400
401///////////////////////////////////////////////////////////////////////////////
402// Layers
403///////////////////////////////////////////////////////////////////////////////
404
405bool OpenGLRenderer::updateLayer(Layer* layer, bool inFrame) {
406    if (layer->deferredUpdateScheduled && layer->renderer
407            && layer->renderNode.get() && layer->renderNode->isRenderable()) {
408
409        if (inFrame) {
410            endTiling();
411            debugOverdraw(false, false);
412        }
413
414        if (CC_UNLIKELY(inFrame || mCaches.drawDeferDisabled)) {
415            layer->render(*this);
416        } else {
417            layer->defer(*this);
418        }
419
420        if (inFrame) {
421            resumeAfterLayer();
422            startTilingCurrentClip();
423        }
424
425        layer->debugDrawUpdate = mCaches.debugLayersUpdates;
426        layer->hasDrawnSinceUpdate = false;
427
428        return true;
429    }
430
431    return false;
432}
433
434void OpenGLRenderer::updateLayers() {
435    // If draw deferring is enabled this method will simply defer
436    // the display list of each individual layer. The layers remain
437    // in the layer updates list which will be cleared by flushLayers().
438    int count = mLayerUpdates.size();
439    if (count > 0) {
440        if (CC_UNLIKELY(mCaches.drawDeferDisabled)) {
441            startMark("Layer Updates");
442        } else {
443            startMark("Defer Layer Updates");
444        }
445
446        // Note: it is very important to update the layers in order
447        for (int i = 0; i < count; i++) {
448            Layer* layer = mLayerUpdates.itemAt(i).get();
449            updateLayer(layer, false);
450        }
451
452        if (CC_UNLIKELY(mCaches.drawDeferDisabled)) {
453            mLayerUpdates.clear();
454            mRenderState.bindFramebuffer(onGetTargetFbo());
455        }
456        endMark();
457    }
458}
459
460void OpenGLRenderer::flushLayers() {
461    int count = mLayerUpdates.size();
462    if (count > 0) {
463        startMark("Apply Layer Updates");
464
465        // Note: it is very important to update the layers in order
466        for (int i = 0; i < count; i++) {
467            mLayerUpdates.itemAt(i)->flush();
468        }
469
470        mLayerUpdates.clear();
471        mRenderState.bindFramebuffer(onGetTargetFbo());
472
473        endMark();
474    }
475}
476
477void OpenGLRenderer::pushLayerUpdate(Layer* layer) {
478    if (layer) {
479        // Make sure we don't introduce duplicates.
480        // SortedVector would do this automatically but we need to respect
481        // the insertion order. The linear search is not an issue since
482        // this list is usually very short (typically one item, at most a few)
483        for (int i = mLayerUpdates.size() - 1; i >= 0; i--) {
484            if (mLayerUpdates.itemAt(i) == layer) {
485                return;
486            }
487        }
488        mLayerUpdates.push_back(layer);
489    }
490}
491
492void OpenGLRenderer::cancelLayerUpdate(Layer* layer) {
493    if (layer) {
494        for (int i = mLayerUpdates.size() - 1; i >= 0; i--) {
495            if (mLayerUpdates.itemAt(i) == layer) {
496                mLayerUpdates.removeAt(i);
497                break;
498            }
499        }
500    }
501}
502
503void OpenGLRenderer::flushLayerUpdates() {
504    ATRACE_NAME("Update HW Layers");
505    mRenderState.blend().syncEnabled();
506    updateLayers();
507    flushLayers();
508    // Wait for all the layer updates to be executed
509    AutoFence fence;
510}
511
512void OpenGLRenderer::markLayersAsBuildLayers() {
513    for (size_t i = 0; i < mLayerUpdates.size(); i++) {
514        mLayerUpdates[i]->wasBuildLayered = true;
515    }
516}
517
518///////////////////////////////////////////////////////////////////////////////
519// State management
520///////////////////////////////////////////////////////////////////////////////
521
522void OpenGLRenderer::onSnapshotRestored(const Snapshot& removed, const Snapshot& restored) {
523    bool restoreViewport = removed.flags & Snapshot::kFlagIsFboLayer;
524    bool restoreClip = removed.flags & Snapshot::kFlagClipSet;
525    bool restoreLayer = removed.flags & Snapshot::kFlagIsLayer;
526
527    if (restoreViewport) {
528        mRenderState.setViewport(getViewportWidth(), getViewportHeight());
529    }
530
531    if (restoreClip) {
532        dirtyClip();
533    }
534
535    if (restoreLayer) {
536        endMark(); // Savelayer
537        ATRACE_END(); // SaveLayer
538        startMark("ComposeLayer");
539        composeLayer(removed, restored);
540        endMark();
541    }
542}
543
544///////////////////////////////////////////////////////////////////////////////
545// Layers
546///////////////////////////////////////////////////////////////////////////////
547
548int OpenGLRenderer::saveLayer(float left, float top, float right, float bottom,
549        const SkPaint* paint, int flags, const SkPath* convexMask) {
550    // force matrix/clip isolation for layer
551    flags |= SkCanvas::kClip_SaveFlag | SkCanvas::kMatrix_SaveFlag;
552
553    const int count = mState.saveSnapshot(flags);
554
555    if (!mState.currentlyIgnored()) {
556        createLayer(left, top, right, bottom, paint, flags, convexMask);
557    }
558
559    return count;
560}
561
562void OpenGLRenderer::calculateLayerBoundsAndClip(Rect& bounds, Rect& clip, bool fboLayer) {
563    const Rect untransformedBounds(bounds);
564
565    currentTransform()->mapRect(bounds);
566
567    // Layers only make sense if they are in the framebuffer's bounds
568    if (bounds.intersect(mState.currentClipRect())) {
569        // We cannot work with sub-pixels in this case
570        bounds.snapToPixelBoundaries();
571
572        // When the layer is not an FBO, we may use glCopyTexImage so we
573        // need to make sure the layer does not extend outside the bounds
574        // of the framebuffer
575        const Snapshot& previous = *(currentSnapshot()->previous);
576        Rect previousViewport(0, 0, previous.getViewportWidth(), previous.getViewportHeight());
577        if (!bounds.intersect(previousViewport)) {
578            bounds.setEmpty();
579        } else if (fboLayer) {
580            clip.set(bounds);
581            mat4 inverse;
582            inverse.loadInverse(*currentTransform());
583            inverse.mapRect(clip);
584            clip.snapToPixelBoundaries();
585            if (clip.intersect(untransformedBounds)) {
586                clip.translate(-untransformedBounds.left, -untransformedBounds.top);
587                bounds.set(untransformedBounds);
588            } else {
589                clip.setEmpty();
590            }
591        }
592    } else {
593        bounds.setEmpty();
594    }
595}
596
597void OpenGLRenderer::updateSnapshotIgnoreForLayer(const Rect& bounds, const Rect& clip,
598        bool fboLayer, int alpha) {
599    if (bounds.isEmpty() || bounds.getWidth() > mCaches.maxTextureSize ||
600            bounds.getHeight() > mCaches.maxTextureSize ||
601            (fboLayer && clip.isEmpty())) {
602        writableSnapshot()->empty = fboLayer;
603    } else {
604        writableSnapshot()->invisible = writableSnapshot()->invisible || (alpha <= 0 && fboLayer);
605    }
606}
607
608int OpenGLRenderer::saveLayerDeferred(float left, float top, float right, float bottom,
609        const SkPaint* paint, int flags) {
610    const int count = mState.saveSnapshot(flags);
611
612    if (!mState.currentlyIgnored() && (flags & SkCanvas::kClipToLayer_SaveFlag)) {
613        // initialize the snapshot as though it almost represents an FBO layer so deferred draw
614        // operations will be able to store and restore the current clip and transform info, and
615        // quick rejection will be correct (for display lists)
616
617        Rect bounds(left, top, right, bottom);
618        Rect clip;
619        calculateLayerBoundsAndClip(bounds, clip, true);
620        updateSnapshotIgnoreForLayer(bounds, clip, true, getAlphaDirect(paint));
621
622        if (!mState.currentlyIgnored()) {
623            writableSnapshot()->resetTransform(-bounds.left, -bounds.top, 0.0f);
624            writableSnapshot()->resetClip(clip.left, clip.top, clip.right, clip.bottom);
625            writableSnapshot()->initializeViewport(bounds.getWidth(), bounds.getHeight());
626            writableSnapshot()->roundRectClipState = nullptr;
627        }
628    }
629
630    return count;
631}
632
633/**
634 * Layers are viewed by Skia are slightly different than layers in image editing
635 * programs (for instance.) When a layer is created, previously created layers
636 * and the frame buffer still receive every drawing command. For instance, if a
637 * layer is created and a shape intersecting the bounds of the layers and the
638 * framebuffer is draw, the shape will be drawn on both (unless the layer was
639 * created with the SkCanvas::kClipToLayer_SaveFlag flag.)
640 *
641 * A way to implement layers is to create an FBO for each layer, backed by an RGBA
642 * texture. Unfortunately, this is inefficient as it requires every primitive to
643 * be drawn n + 1 times, where n is the number of active layers. In practice this
644 * means, for every primitive:
645 *   - Switch active frame buffer
646 *   - Change viewport, clip and projection matrix
647 *   - Issue the drawing
648 *
649 * Switching rendering target n + 1 times per drawn primitive is extremely costly.
650 * To avoid this, layers are implemented in a different way here, at least in the
651 * general case. FBOs are used, as an optimization, when the "clip to layer" flag
652 * is set. When this flag is set we can redirect all drawing operations into a
653 * single FBO.
654 *
655 * This implementation relies on the frame buffer being at least RGBA 8888. When
656 * a layer is created, only a texture is created, not an FBO. The content of the
657 * frame buffer contained within the layer's bounds is copied into this texture
658 * using glCopyTexImage2D(). The layer's region is then cleared(1) in the frame
659 * buffer and drawing continues as normal. This technique therefore treats the
660 * frame buffer as a scratch buffer for the layers.
661 *
662 * To compose the layers back onto the frame buffer, each layer texture
663 * (containing the original frame buffer data) is drawn as a simple quad over
664 * the frame buffer. The trick is that the quad is set as the composition
665 * destination in the blending equation, and the frame buffer becomes the source
666 * of the composition.
667 *
668 * Drawing layers with an alpha value requires an extra step before composition.
669 * An empty quad is drawn over the layer's region in the frame buffer. This quad
670 * is drawn with the rgba color (0,0,0,alpha). The alpha value offered by the
671 * quad is used to multiply the colors in the frame buffer. This is achieved by
672 * changing the GL blend functions for the GL_FUNC_ADD blend equation to
673 * GL_ZERO, GL_SRC_ALPHA.
674 *
675 * Because glCopyTexImage2D() can be slow, an alternative implementation might
676 * be use to draw a single clipped layer. The implementation described above
677 * is correct in every case.
678 *
679 * (1) The frame buffer is actually not cleared right away. To allow the GPU
680 *     to potentially optimize series of calls to glCopyTexImage2D, the frame
681 *     buffer is left untouched until the first drawing operation. Only when
682 *     something actually gets drawn are the layers regions cleared.
683 */
684bool OpenGLRenderer::createLayer(float left, float top, float right, float bottom,
685        const SkPaint* paint, int flags, const SkPath* convexMask) {
686    LAYER_LOGD("Requesting layer %.2fx%.2f", right - left, bottom - top);
687    LAYER_LOGD("Layer cache size = %d", mCaches.layerCache.getSize());
688
689    const bool fboLayer = flags & SkCanvas::kClipToLayer_SaveFlag;
690
691    // Window coordinates of the layer
692    Rect clip;
693    Rect bounds(left, top, right, bottom);
694    calculateLayerBoundsAndClip(bounds, clip, fboLayer);
695    updateSnapshotIgnoreForLayer(bounds, clip, fboLayer, getAlphaDirect(paint));
696
697    // Bail out if we won't draw in this snapshot
698    if (mState.currentlyIgnored()) {
699        return false;
700    }
701
702    mCaches.textureState().activateTexture(0);
703    Layer* layer = mCaches.layerCache.get(mRenderState, bounds.getWidth(), bounds.getHeight());
704    if (!layer) {
705        return false;
706    }
707
708    layer->setPaint(paint);
709    layer->layer.set(bounds);
710    layer->texCoords.set(0.0f, bounds.getHeight() / float(layer->getHeight()),
711            bounds.getWidth() / float(layer->getWidth()), 0.0f);
712
713    layer->setBlend(true);
714    layer->setDirty(false);
715    layer->setConvexMask(convexMask); // note: the mask must be cleared before returning to the cache
716
717    // Save the layer in the snapshot
718    writableSnapshot()->flags |= Snapshot::kFlagIsLayer;
719    writableSnapshot()->layer = layer;
720
721    ATRACE_FORMAT_BEGIN("%ssaveLayer %ux%u",
722            fboLayer ? "" : "unclipped ",
723            layer->getWidth(), layer->getHeight());
724    startMark("SaveLayer");
725    if (fboLayer) {
726        return createFboLayer(layer, bounds, clip);
727    } else {
728        // Copy the framebuffer into the layer
729        layer->bindTexture();
730        if (!bounds.isEmpty()) {
731            if (layer->isEmpty()) {
732                // Workaround for some GL drivers. When reading pixels lying outside
733                // of the window we should get undefined values for those pixels.
734                // Unfortunately some drivers will turn the entire target texture black
735                // when reading outside of the window.
736                glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, layer->getWidth(), layer->getHeight(),
737                        0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
738                layer->setEmpty(false);
739            }
740
741            glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0,
742                    bounds.left, getViewportHeight() - bounds.bottom,
743                    bounds.getWidth(), bounds.getHeight());
744
745            // Enqueue the buffer coordinates to clear the corresponding region later
746            mLayers.push_back(Rect(bounds));
747        }
748    }
749
750    return true;
751}
752
753bool OpenGLRenderer::createFboLayer(Layer* layer, Rect& bounds, Rect& clip) {
754    layer->clipRect.set(clip);
755    layer->setFbo(mCaches.fboCache.get());
756
757    writableSnapshot()->region = &writableSnapshot()->layer->region;
758    writableSnapshot()->flags |= Snapshot::kFlagFboTarget | Snapshot::kFlagIsFboLayer;
759    writableSnapshot()->fbo = layer->getFbo();
760    writableSnapshot()->resetTransform(-bounds.left, -bounds.top, 0.0f);
761    writableSnapshot()->resetClip(clip.left, clip.top, clip.right, clip.bottom);
762    writableSnapshot()->initializeViewport(bounds.getWidth(), bounds.getHeight());
763    writableSnapshot()->roundRectClipState = nullptr;
764
765    endTiling();
766    debugOverdraw(false, false);
767    // Bind texture to FBO
768    mRenderState.bindFramebuffer(layer->getFbo());
769    layer->bindTexture();
770
771    // Initialize the texture if needed
772    if (layer->isEmpty()) {
773        layer->allocateTexture();
774        layer->setEmpty(false);
775    }
776
777    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
778            layer->getTexture(), 0);
779
780    // Expand the startTiling region by 1
781    startTilingCurrentClip(true, true);
782
783    // Clear the FBO, expand the clear region by 1 to get nice bilinear filtering
784    mRenderState.scissor().setEnabled(true);
785    mRenderState.scissor().set(clip.left - 1.0f, bounds.getHeight() - clip.bottom - 1.0f,
786            clip.getWidth() + 2.0f, clip.getHeight() + 2.0f);
787    glClear(GL_COLOR_BUFFER_BIT);
788
789    dirtyClip();
790
791    // Change the ortho projection
792    mRenderState.setViewport(bounds.getWidth(), bounds.getHeight());
793    return true;
794}
795
796/**
797 * Read the documentation of createLayer() before doing anything in this method.
798 */
799void OpenGLRenderer::composeLayer(const Snapshot& removed, const Snapshot& restored) {
800    if (!removed.layer) {
801        ALOGE("Attempting to compose a layer that does not exist");
802        return;
803    }
804
805    Layer* layer = removed.layer;
806    const Rect& rect = layer->layer;
807    const bool fboLayer = removed.flags & Snapshot::kFlagIsFboLayer;
808
809    bool clipRequired = false;
810    mState.calculateQuickRejectForScissor(rect.left, rect.top, rect.right, rect.bottom,
811            &clipRequired, nullptr, false); // safely ignore return, should never be rejected
812    mRenderState.scissor().setEnabled(mScissorOptimizationDisabled || clipRequired);
813
814    if (fboLayer) {
815        endTiling();
816
817        // Detach the texture from the FBO
818        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 0, 0);
819
820        layer->removeFbo(false);
821
822        // Unbind current FBO and restore previous one
823        mRenderState.bindFramebuffer(restored.fbo);
824        debugOverdraw(true, false);
825
826        startTilingCurrentClip();
827    }
828
829    if (!fboLayer && layer->getAlpha() < 255) {
830        SkPaint layerPaint;
831        layerPaint.setAlpha(layer->getAlpha());
832        layerPaint.setXfermodeMode(SkXfermode::kDstIn_Mode);
833        layerPaint.setColorFilter(layer->getColorFilter());
834
835        drawColorRect(rect.left, rect.top, rect.right, rect.bottom, &layerPaint, true);
836        // Required below, composeLayerRect() will divide by 255
837        layer->setAlpha(255);
838    }
839
840    mRenderState.meshState().unbindMeshBuffer();
841
842    mCaches.textureState().activateTexture(0);
843
844    // When the layer is stored in an FBO, we can save a bit of fillrate by
845    // drawing only the dirty region
846    if (fboLayer) {
847        dirtyLayer(rect.left, rect.top, rect.right, rect.bottom, *restored.transform);
848        composeLayerRegion(layer, rect);
849    } else if (!rect.isEmpty()) {
850        dirtyLayer(rect.left, rect.top, rect.right, rect.bottom);
851
852        save(0);
853        // the layer contains screen buffer content that shouldn't be alpha modulated
854        // (and any necessary alpha modulation was handled drawing into the layer)
855        writableSnapshot()->alpha = 1.0f;
856        composeLayerRect(layer, rect, true);
857        restore();
858    }
859
860    dirtyClip();
861
862    // Failing to add the layer to the cache should happen only if the layer is too large
863    layer->setConvexMask(nullptr);
864    if (!mCaches.layerCache.put(layer)) {
865        LAYER_LOGD("Deleting layer");
866        layer->decStrong(nullptr);
867    }
868}
869
870void OpenGLRenderer::drawTextureLayer(Layer* layer, const Rect& rect) {
871    float alpha = getLayerAlpha(layer);
872
873    setupDraw();
874    if (layer->getRenderTarget() == GL_TEXTURE_2D) {
875        setupDrawWithTexture();
876    } else {
877        setupDrawWithExternalTexture();
878    }
879    setupDrawTextureTransform();
880    setupDrawColor(alpha, alpha, alpha, alpha);
881    setupDrawColorFilter(layer->getColorFilter());
882    setupDrawBlending(layer);
883    setupDrawProgram();
884    setupDrawPureColorUniforms();
885    setupDrawColorFilterUniforms(layer->getColorFilter());
886    if (layer->getRenderTarget() == GL_TEXTURE_2D) {
887        setupDrawTexture(layer->getTexture());
888    } else {
889        setupDrawExternalTexture(layer->getTexture());
890    }
891    if (currentTransform()->isPureTranslate() &&
892            !layer->getForceFilter() &&
893            layer->getWidth() == (uint32_t) rect.getWidth() &&
894            layer->getHeight() == (uint32_t) rect.getHeight()) {
895        const float x = (int) floorf(rect.left + currentTransform()->getTranslateX() + 0.5f);
896        const float y = (int) floorf(rect.top + currentTransform()->getTranslateY() + 0.5f);
897
898        layer->setFilter(GL_NEAREST);
899        setupDrawModelView(kModelViewMode_TranslateAndScale, false,
900                x, y, x + rect.getWidth(), y + rect.getHeight(), true);
901    } else {
902        layer->setFilter(GL_LINEAR);
903        setupDrawModelView(kModelViewMode_TranslateAndScale, false,
904                rect.left, rect.top, rect.right, rect.bottom);
905    }
906    setupDrawTextureTransformUniforms(layer->getTexTransform());
907    setupDrawMesh(&mMeshVertices[0].x, &mMeshVertices[0].u);
908
909    glDrawArrays(GL_TRIANGLE_STRIP, 0, kMeshCount);
910}
911
912void OpenGLRenderer::composeLayerRect(Layer* layer, const Rect& rect, bool swap) {
913    if (layer->isTextureLayer()) {
914        EVENT_LOGD("composeTextureLayerRect");
915        resetDrawTextureTexCoords(0.0f, 1.0f, 1.0f, 0.0f);
916        drawTextureLayer(layer, rect);
917        resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
918    } else {
919        EVENT_LOGD("composeHardwareLayerRect");
920        const Rect& texCoords = layer->texCoords;
921        resetDrawTextureTexCoords(texCoords.left, texCoords.top,
922                texCoords.right, texCoords.bottom);
923
924        float x = rect.left;
925        float y = rect.top;
926        bool simpleTransform = currentTransform()->isPureTranslate() &&
927                layer->getWidth() == (uint32_t) rect.getWidth() &&
928                layer->getHeight() == (uint32_t) rect.getHeight();
929
930        if (simpleTransform) {
931            // When we're swapping, the layer is already in screen coordinates
932            if (!swap) {
933                x = (int) floorf(rect.left + currentTransform()->getTranslateX() + 0.5f);
934                y = (int) floorf(rect.top + currentTransform()->getTranslateY() + 0.5f);
935            }
936
937            layer->setFilter(GL_NEAREST, true);
938        } else {
939            layer->setFilter(GL_LINEAR, true);
940        }
941
942        SkPaint layerPaint;
943        layerPaint.setAlpha(getLayerAlpha(layer) * 255);
944        layerPaint.setXfermodeMode(layer->getMode());
945        layerPaint.setColorFilter(layer->getColorFilter());
946
947        bool blend = layer->isBlend() || getLayerAlpha(layer) < 1.0f;
948        drawTextureMesh(x, y, x + rect.getWidth(), y + rect.getHeight(),
949                layer->getTexture(), &layerPaint, blend,
950                &mMeshVertices[0].x, &mMeshVertices[0].u,
951                GL_TRIANGLE_STRIP, kMeshCount, swap, swap || simpleTransform);
952
953        resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
954    }
955}
956
957/**
958 * Issues the command X, and if we're composing a save layer to the fbo or drawing a newly updated
959 * hardware layer with overdraw debug on, draws again to the stencil only, so that these draw
960 * operations are correctly counted twice for overdraw. NOTE: assumes composeLayerRegion only used
961 * by saveLayer's restore
962 */
963#define DRAW_DOUBLE_STENCIL_IF(COND, DRAW_COMMAND) {                               \
964        DRAW_COMMAND;                                                              \
965        if (CC_UNLIKELY(mCaches.debugOverdraw && onGetTargetFbo() == 0 && COND)) { \
966            glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);                   \
967            DRAW_COMMAND;                                                          \
968            glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);                       \
969        }                                                                          \
970    }
971
972#define DRAW_DOUBLE_STENCIL(DRAW_COMMAND) DRAW_DOUBLE_STENCIL_IF(true, DRAW_COMMAND)
973
974// This class is purely for inspection. It inherits from SkShader, but Skia does not know how to
975// use it. The OpenGLRenderer will look at it to find its Layer and whether it is opaque.
976class LayerShader : public SkShader {
977public:
978    LayerShader(Layer* layer, const SkMatrix* localMatrix)
979    : INHERITED(localMatrix)
980    , mLayer(layer) {
981    }
982
983    virtual bool asACustomShader(void** data) const override {
984        if (data) {
985            *data = static_cast<void*>(mLayer);
986        }
987        return true;
988    }
989
990    virtual bool isOpaque() const override {
991        return !mLayer->isBlend();
992    }
993
994protected:
995    virtual void shadeSpan(int x, int y, SkPMColor[], int count) {
996        LOG_ALWAYS_FATAL("LayerShader should never be drawn with raster backend.");
997    }
998
999    virtual void flatten(SkWriteBuffer&) const override {
1000        LOG_ALWAYS_FATAL("LayerShader should never be flattened.");
1001    }
1002
1003    virtual Factory getFactory() const override {
1004        LOG_ALWAYS_FATAL("LayerShader should never be created from a stream.");
1005        return nullptr;
1006    }
1007private:
1008    // Unowned.
1009    Layer* mLayer;
1010    typedef SkShader INHERITED;
1011};
1012
1013void OpenGLRenderer::composeLayerRegion(Layer* layer, const Rect& rect) {
1014    if (CC_UNLIKELY(layer->region.isEmpty())) return; // nothing to draw
1015
1016    if (layer->getConvexMask()) {
1017        save(SkCanvas::kClip_SaveFlag | SkCanvas::kMatrix_SaveFlag);
1018
1019        // clip to the area of the layer the mask can be larger
1020        clipRect(rect.left, rect.top, rect.right, rect.bottom, SkRegion::kIntersect_Op);
1021
1022        SkPaint paint;
1023        paint.setAntiAlias(true);
1024        paint.setColor(SkColorSetARGB(int(getLayerAlpha(layer) * 255), 0, 0, 0));
1025
1026        // create LayerShader to map SaveLayer content into subsequent draw
1027        SkMatrix shaderMatrix;
1028        shaderMatrix.setTranslate(rect.left, rect.bottom);
1029        shaderMatrix.preScale(1, -1);
1030        LayerShader layerShader(layer, &shaderMatrix);
1031        paint.setShader(&layerShader);
1032
1033        // Since the drawing primitive is defined in local drawing space,
1034        // we don't need to modify the draw matrix
1035        const SkPath* maskPath = layer->getConvexMask();
1036        DRAW_DOUBLE_STENCIL(drawConvexPath(*maskPath, &paint));
1037
1038        paint.setShader(nullptr);
1039        restore();
1040
1041        return;
1042    }
1043
1044    if (layer->region.isRect()) {
1045        layer->setRegionAsRect();
1046
1047        DRAW_DOUBLE_STENCIL(composeLayerRect(layer, layer->regionRect));
1048
1049        layer->region.clear();
1050        return;
1051    }
1052
1053    EVENT_LOGD("composeLayerRegion");
1054    // standard Region based draw
1055    size_t count;
1056    const android::Rect* rects;
1057    Region safeRegion;
1058    if (CC_LIKELY(hasRectToRectTransform())) {
1059        rects = layer->region.getArray(&count);
1060    } else {
1061        safeRegion = Region::createTJunctionFreeRegion(layer->region);
1062        rects = safeRegion.getArray(&count);
1063    }
1064
1065    const float alpha = getLayerAlpha(layer);
1066    const float texX = 1.0f / float(layer->getWidth());
1067    const float texY = 1.0f / float(layer->getHeight());
1068    const float height = rect.getHeight();
1069
1070    setupDraw();
1071
1072    // We must get (and therefore bind) the region mesh buffer
1073    // after we setup drawing in case we need to mess with the
1074    // stencil buffer in setupDraw()
1075    TextureVertex* mesh = mCaches.getRegionMesh();
1076    uint32_t numQuads = 0;
1077
1078    setupDrawWithTexture();
1079    setupDrawColor(alpha, alpha, alpha, alpha);
1080    setupDrawColorFilter(layer->getColorFilter());
1081    setupDrawBlending(layer);
1082    setupDrawProgram();
1083    setupDrawDirtyRegionsDisabled();
1084    setupDrawPureColorUniforms();
1085    setupDrawColorFilterUniforms(layer->getColorFilter());
1086    setupDrawTexture(layer->getTexture());
1087    if (currentTransform()->isPureTranslate()) {
1088        const float x = (int) floorf(rect.left + currentTransform()->getTranslateX() + 0.5f);
1089        const float y = (int) floorf(rect.top + currentTransform()->getTranslateY() + 0.5f);
1090
1091        layer->setFilter(GL_NEAREST);
1092        setupDrawModelView(kModelViewMode_Translate, false,
1093                x, y, x + rect.getWidth(), y + rect.getHeight(), true);
1094    } else {
1095        layer->setFilter(GL_LINEAR);
1096        setupDrawModelView(kModelViewMode_Translate, false,
1097                rect.left, rect.top, rect.right, rect.bottom);
1098    }
1099    setupDrawMeshIndices(&mesh[0].x, &mesh[0].u);
1100
1101    for (size_t i = 0; i < count; i++) {
1102        const android::Rect* r = &rects[i];
1103
1104        const float u1 = r->left * texX;
1105        const float v1 = (height - r->top) * texY;
1106        const float u2 = r->right * texX;
1107        const float v2 = (height - r->bottom) * texY;
1108
1109        // TODO: Reject quads outside of the clip
1110        TextureVertex::set(mesh++, r->left, r->top, u1, v1);
1111        TextureVertex::set(mesh++, r->right, r->top, u2, v1);
1112        TextureVertex::set(mesh++, r->left, r->bottom, u1, v2);
1113        TextureVertex::set(mesh++, r->right, r->bottom, u2, v2);
1114
1115        numQuads++;
1116
1117        if (numQuads >= kMaxNumberOfQuads) {
1118            DRAW_DOUBLE_STENCIL(glDrawElements(GL_TRIANGLES, numQuads * 6,
1119                    GL_UNSIGNED_SHORT, nullptr));
1120            numQuads = 0;
1121            mesh = mCaches.getRegionMesh();
1122        }
1123    }
1124
1125    if (numQuads > 0) {
1126        DRAW_DOUBLE_STENCIL(glDrawElements(GL_TRIANGLES, numQuads * 6,
1127                GL_UNSIGNED_SHORT, nullptr));
1128    }
1129
1130#if DEBUG_LAYERS_AS_REGIONS
1131    drawRegionRectsDebug(layer->region);
1132#endif
1133
1134    layer->region.clear();
1135}
1136
1137#if DEBUG_LAYERS_AS_REGIONS
1138void OpenGLRenderer::drawRegionRectsDebug(const Region& region) {
1139    size_t count;
1140    const android::Rect* rects = region.getArray(&count);
1141
1142    uint32_t colors[] = {
1143            0x7fff0000, 0x7f00ff00,
1144            0x7f0000ff, 0x7fff00ff,
1145    };
1146
1147    int offset = 0;
1148    int32_t top = rects[0].top;
1149
1150    for (size_t i = 0; i < count; i++) {
1151        if (top != rects[i].top) {
1152            offset ^= 0x2;
1153            top = rects[i].top;
1154        }
1155
1156        SkPaint paint;
1157        paint.setColor(colors[offset + (i & 0x1)]);
1158        Rect r(rects[i].left, rects[i].top, rects[i].right, rects[i].bottom);
1159        drawColorRect(r.left, r.top, r.right, r.bottom, paint);
1160    }
1161}
1162#endif
1163
1164void OpenGLRenderer::drawRegionRects(const SkRegion& region, const SkPaint& paint, bool dirty) {
1165    Vector<float> rects;
1166
1167    SkRegion::Iterator it(region);
1168    while (!it.done()) {
1169        const SkIRect& r = it.rect();
1170        rects.push(r.fLeft);
1171        rects.push(r.fTop);
1172        rects.push(r.fRight);
1173        rects.push(r.fBottom);
1174        it.next();
1175    }
1176
1177    drawColorRects(rects.array(), rects.size(), &paint, true, dirty, false);
1178}
1179
1180void OpenGLRenderer::dirtyLayer(const float left, const float top,
1181        const float right, const float bottom, const mat4 transform) {
1182    if (hasLayer()) {
1183        Rect bounds(left, top, right, bottom);
1184        transform.mapRect(bounds);
1185        dirtyLayerUnchecked(bounds, getRegion());
1186    }
1187}
1188
1189void OpenGLRenderer::dirtyLayer(const float left, const float top,
1190        const float right, const float bottom) {
1191    if (hasLayer()) {
1192        Rect bounds(left, top, right, bottom);
1193        dirtyLayerUnchecked(bounds, getRegion());
1194    }
1195}
1196
1197void OpenGLRenderer::dirtyLayerUnchecked(Rect& bounds, Region* region) {
1198    if (bounds.intersect(mState.currentClipRect())) {
1199        bounds.snapToPixelBoundaries();
1200        android::Rect dirty(bounds.left, bounds.top, bounds.right, bounds.bottom);
1201        if (!dirty.isEmpty()) {
1202            region->orSelf(dirty);
1203        }
1204    }
1205}
1206
1207void OpenGLRenderer::issueIndexedQuadDraw(Vertex* mesh, GLsizei quadsCount) {
1208    GLsizei elementsCount = quadsCount * 6;
1209    while (elementsCount > 0) {
1210        GLsizei drawCount = min(elementsCount, (GLsizei) kMaxNumberOfQuads * 6);
1211
1212        setupDrawIndexedVertices(&mesh[0].x);
1213        glDrawElements(GL_TRIANGLES, drawCount, GL_UNSIGNED_SHORT, nullptr);
1214
1215        elementsCount -= drawCount;
1216        // Though there are 4 vertices in a quad, we use 6 indices per
1217        // quad to draw with GL_TRIANGLES
1218        mesh += (drawCount / 6) * 4;
1219    }
1220}
1221
1222void OpenGLRenderer::clearLayerRegions() {
1223    const size_t count = mLayers.size();
1224    if (count == 0) return;
1225
1226    if (!mState.currentlyIgnored()) {
1227        EVENT_LOGD("clearLayerRegions");
1228        // Doing several glScissor/glClear here can negatively impact
1229        // GPUs with a tiler architecture, instead we draw quads with
1230        // the Clear blending mode
1231
1232        // The list contains bounds that have already been clipped
1233        // against their initial clip rect, and the current clip
1234        // is likely different so we need to disable clipping here
1235        bool scissorChanged = mRenderState.scissor().setEnabled(false);
1236
1237        Vertex mesh[count * 4];
1238        Vertex* vertex = mesh;
1239
1240        for (uint32_t i = 0; i < count; i++) {
1241            const Rect& bounds = mLayers[i];
1242
1243            Vertex::set(vertex++, bounds.left, bounds.top);
1244            Vertex::set(vertex++, bounds.right, bounds.top);
1245            Vertex::set(vertex++, bounds.left, bounds.bottom);
1246            Vertex::set(vertex++, bounds.right, bounds.bottom);
1247        }
1248        // We must clear the list of dirty rects before we
1249        // call setupDraw() to prevent stencil setup to do
1250        // the same thing again
1251        mLayers.clear();
1252
1253        SkPaint clearPaint;
1254        clearPaint.setXfermodeMode(SkXfermode::kClear_Mode);
1255
1256        setupDraw(false);
1257        setupDrawColor(0.0f, 0.0f, 0.0f, 1.0f);
1258        setupDrawBlending(&clearPaint, true);
1259        setupDrawProgram();
1260        setupDrawPureColorUniforms();
1261        setupDrawModelView(kModelViewMode_Translate, false,
1262                0.0f, 0.0f, 0.0f, 0.0f, true);
1263
1264        issueIndexedQuadDraw(&mesh[0], count);
1265
1266        if (scissorChanged) mRenderState.scissor().setEnabled(true);
1267    } else {
1268        mLayers.clear();
1269    }
1270}
1271
1272///////////////////////////////////////////////////////////////////////////////
1273// State Deferral
1274///////////////////////////////////////////////////////////////////////////////
1275
1276bool OpenGLRenderer::storeDisplayState(DeferredDisplayState& state, int stateDeferFlags) {
1277    const Rect& currentClip = mState.currentClipRect();
1278    const mat4* currentMatrix = currentTransform();
1279
1280    if (stateDeferFlags & kStateDeferFlag_Draw) {
1281        // state has bounds initialized in local coordinates
1282        if (!state.mBounds.isEmpty()) {
1283            currentMatrix->mapRect(state.mBounds);
1284            Rect clippedBounds(state.mBounds);
1285            // NOTE: if we ever want to use this clipping info to drive whether the scissor
1286            // is used, it should more closely duplicate the quickReject logic (in how it uses
1287            // snapToPixelBoundaries)
1288
1289            if (!clippedBounds.intersect(currentClip)) {
1290                // quick rejected
1291                return true;
1292            }
1293
1294            state.mClipSideFlags = kClipSide_None;
1295            if (!currentClip.contains(state.mBounds)) {
1296                int& flags = state.mClipSideFlags;
1297                // op partially clipped, so record which sides are clipped for clip-aware merging
1298                if (currentClip.left > state.mBounds.left) flags |= kClipSide_Left;
1299                if (currentClip.top > state.mBounds.top) flags |= kClipSide_Top;
1300                if (currentClip.right < state.mBounds.right) flags |= kClipSide_Right;
1301                if (currentClip.bottom < state.mBounds.bottom) flags |= kClipSide_Bottom;
1302            }
1303            state.mBounds.set(clippedBounds);
1304        } else {
1305            // Empty bounds implies size unknown. Label op as conservatively clipped to disable
1306            // overdraw avoidance (since we don't know what it overlaps)
1307            state.mClipSideFlags = kClipSide_ConservativeFull;
1308            state.mBounds.set(currentClip);
1309        }
1310    }
1311
1312    state.mClipValid = (stateDeferFlags & kStateDeferFlag_Clip);
1313    if (state.mClipValid) {
1314        state.mClip.set(currentClip);
1315    }
1316
1317    // Transform, drawModifiers, and alpha always deferred, since they are used by state operations
1318    // (Note: saveLayer/restore use colorFilter and alpha, so we just save restore everything)
1319    state.mMatrix.load(*currentMatrix);
1320    state.mDrawModifiers = mDrawModifiers;
1321    state.mAlpha = currentSnapshot()->alpha;
1322
1323    // always store/restore, since it's just a pointer
1324    state.mRoundRectClipState = currentSnapshot()->roundRectClipState;
1325    return false;
1326}
1327
1328void OpenGLRenderer::restoreDisplayState(const DeferredDisplayState& state, bool skipClipRestore) {
1329    setMatrix(state.mMatrix);
1330    writableSnapshot()->alpha = state.mAlpha;
1331    mDrawModifiers = state.mDrawModifiers;
1332    writableSnapshot()->roundRectClipState = state.mRoundRectClipState;
1333
1334    if (state.mClipValid && !skipClipRestore) {
1335        writableSnapshot()->setClip(state.mClip.left, state.mClip.top,
1336                state.mClip.right, state.mClip.bottom);
1337        dirtyClip();
1338    }
1339}
1340
1341/**
1342 * Merged multidraw (such as in drawText and drawBitmaps rely on the fact that no clipping is done
1343 * in the draw path. Instead, clipping is done ahead of time - either as a single clip rect (when at
1344 * least one op is clipped), or disabled entirely (because no merged op is clipped)
1345 *
1346 * This method should be called when restoreDisplayState() won't be restoring the clip
1347 */
1348void OpenGLRenderer::setupMergedMultiDraw(const Rect* clipRect) {
1349    if (clipRect != nullptr) {
1350        writableSnapshot()->setClip(clipRect->left, clipRect->top, clipRect->right, clipRect->bottom);
1351    } else {
1352        writableSnapshot()->setClip(0, 0, mState.getWidth(), mState.getHeight());
1353    }
1354    dirtyClip();
1355    bool enableScissor = (clipRect != nullptr) || mScissorOptimizationDisabled;
1356    mRenderState.scissor().setEnabled(enableScissor);
1357}
1358
1359///////////////////////////////////////////////////////////////////////////////
1360// Clipping
1361///////////////////////////////////////////////////////////////////////////////
1362
1363void OpenGLRenderer::setScissorFromClip() {
1364    Rect clip(mState.currentClipRect());
1365    clip.snapToPixelBoundaries();
1366
1367    if (mRenderState.scissor().set(clip.left, getViewportHeight() - clip.bottom,
1368            clip.getWidth(), clip.getHeight())) {
1369        mState.setDirtyClip(false);
1370    }
1371}
1372
1373void OpenGLRenderer::ensureStencilBuffer() {
1374    // Thanks to the mismatch between EGL and OpenGL ES FBO we
1375    // cannot attach a stencil buffer to fbo0 dynamically. Let's
1376    // just hope we have one when hasLayer() returns false.
1377    if (hasLayer()) {
1378        attachStencilBufferToLayer(currentSnapshot()->layer);
1379    }
1380}
1381
1382void OpenGLRenderer::attachStencilBufferToLayer(Layer* layer) {
1383    // The layer's FBO is already bound when we reach this stage
1384    if (!layer->getStencilRenderBuffer()) {
1385        // GL_QCOM_tiled_rendering doesn't like it if a renderbuffer
1386        // is attached after we initiated tiling. We must turn it off,
1387        // attach the new render buffer then turn tiling back on
1388        endTiling();
1389
1390        RenderBuffer* buffer = mCaches.renderBufferCache.get(
1391                Stencil::getSmallestStencilFormat(), layer->getWidth(), layer->getHeight());
1392        layer->setStencilRenderBuffer(buffer);
1393
1394        startTiling(layer->clipRect, layer->layer.getHeight());
1395    }
1396}
1397
1398static void handlePoint(std::vector<Vertex>& rectangleVertices, const Matrix4& transform,
1399        float x, float y) {
1400    Vertex v;
1401    v.x = x;
1402    v.y = y;
1403    transform.mapPoint(v.x, v.y);
1404    rectangleVertices.push_back(v);
1405}
1406
1407static void handlePointNoTransform(std::vector<Vertex>& rectangleVertices, float x, float y) {
1408    Vertex v;
1409    v.x = x;
1410    v.y = y;
1411    rectangleVertices.push_back(v);
1412}
1413
1414void OpenGLRenderer::drawRectangleList(const RectangleList& rectangleList) {
1415    int count = rectangleList.getTransformedRectanglesCount();
1416    std::vector<Vertex> rectangleVertices(count * 4);
1417    Rect scissorBox = rectangleList.calculateBounds();
1418    scissorBox.snapToPixelBoundaries();
1419    for (int i = 0; i < count; ++i) {
1420        const TransformedRectangle& tr(rectangleList.getTransformedRectangle(i));
1421        const Matrix4& transform = tr.getTransform();
1422        Rect bounds = tr.getBounds();
1423        if (transform.rectToRect()) {
1424            transform.mapRect(bounds);
1425            if (!bounds.intersect(scissorBox)) {
1426                bounds.setEmpty();
1427            } else {
1428                handlePointNoTransform(rectangleVertices, bounds.left, bounds.top);
1429                handlePointNoTransform(rectangleVertices, bounds.right, bounds.top);
1430                handlePointNoTransform(rectangleVertices, bounds.left, bounds.bottom);
1431                handlePointNoTransform(rectangleVertices, bounds.right, bounds.bottom);
1432            }
1433        } else {
1434            handlePoint(rectangleVertices, transform, bounds.left, bounds.top);
1435            handlePoint(rectangleVertices, transform, bounds.right, bounds.top);
1436            handlePoint(rectangleVertices, transform, bounds.left, bounds.bottom);
1437            handlePoint(rectangleVertices, transform, bounds.right, bounds.bottom);
1438        }
1439    }
1440
1441    mRenderState.scissor().set(scissorBox.left, getViewportHeight() - scissorBox.bottom,
1442            scissorBox.getWidth(), scissorBox.getHeight());
1443
1444    const SkPaint* paint = nullptr;
1445    setupDraw();
1446    setupDrawNoTexture();
1447    setupDrawColor(0, 0xff * currentSnapshot()->alpha);
1448    setupDrawShader(getShader(paint));
1449    setupDrawColorFilter(getColorFilter(paint));
1450    setupDrawBlending(paint);
1451    setupDrawProgram();
1452    setupDrawDirtyRegionsDisabled();
1453    setupDrawModelView(kModelViewMode_Translate, false,
1454            0.0f, 0.0f, 0.0f, 0.0f, true);
1455    setupDrawColorUniforms(getShader(paint));
1456    setupDrawShaderUniforms(getShader(paint));
1457    setupDrawColorFilterUniforms(getColorFilter(paint));
1458
1459    issueIndexedQuadDraw(&rectangleVertices[0], rectangleVertices.size() / 4);
1460}
1461
1462void OpenGLRenderer::setStencilFromClip() {
1463    if (!mCaches.debugOverdraw) {
1464        if (!currentSnapshot()->clipIsSimple()) {
1465            int incrementThreshold;
1466            EVENT_LOGD("setStencilFromClip - enabling");
1467
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            mState.setDirtyClip(false);
1471
1472            ensureStencilBuffer();
1473
1474            const ClipArea& clipArea = currentSnapshot()->getClipArea();
1475
1476            bool isRectangleList = clipArea.isRectangleList();
1477            if (isRectangleList) {
1478                incrementThreshold = clipArea.getRectangleList().getTransformedRectanglesCount();
1479            } else {
1480                incrementThreshold = 0;
1481            }
1482
1483            mRenderState.stencil().enableWrite(incrementThreshold);
1484
1485            // Clean and update the stencil, but first make sure we restrict drawing
1486            // to the region's bounds
1487            bool resetScissor = mRenderState.scissor().setEnabled(true);
1488            if (resetScissor) {
1489                // The scissor was not set so we now need to update it
1490                setScissorFromClip();
1491            }
1492
1493            mRenderState.stencil().clear();
1494
1495            // stash and disable the outline clip state, since stencil doesn't account for outline
1496            bool storedSkipOutlineClip = mSkipOutlineClip;
1497            mSkipOutlineClip = true;
1498
1499            SkPaint paint;
1500            paint.setColor(SK_ColorBLACK);
1501            paint.setXfermodeMode(SkXfermode::kSrc_Mode);
1502
1503            if (isRectangleList) {
1504                drawRectangleList(clipArea.getRectangleList());
1505            } else {
1506                // NOTE: We could use the region contour path to generate a smaller mesh
1507                //       Since we are using the stencil we could use the red book path
1508                //       drawing technique. It might increase bandwidth usage though.
1509
1510                // The last parameter is important: we are not drawing in the color buffer
1511                // so we don't want to dirty the current layer, if any
1512                drawRegionRects(clipArea.getClipRegion(), paint, false);
1513            }
1514            if (resetScissor) mRenderState.scissor().setEnabled(false);
1515            mSkipOutlineClip = storedSkipOutlineClip;
1516
1517            mRenderState.stencil().enableTest(incrementThreshold);
1518
1519            // Draw the region used to generate the stencil if the appropriate debug
1520            // mode is enabled
1521            // TODO: Implement for rectangle list clip areas
1522            if (mCaches.debugStencilClip == Caches::kStencilShowRegion &&
1523                    !clipArea.isRectangleList()) {
1524                paint.setColor(0x7f0000ff);
1525                paint.setXfermodeMode(SkXfermode::kSrcOver_Mode);
1526                drawRegionRects(currentSnapshot()->getClipRegion(), paint);
1527            }
1528        } else {
1529            EVENT_LOGD("setStencilFromClip - disabling");
1530            mRenderState.stencil().disable();
1531        }
1532    }
1533}
1534
1535/**
1536 * Returns false and sets scissor enable based upon bounds if drawing won't be clipped out.
1537 *
1538 * @param paint if not null, the bounds will be expanded to account for stroke depending on paint
1539 *         style, and tessellated AA ramp
1540 */
1541bool OpenGLRenderer::quickRejectSetupScissor(float left, float top, float right, float bottom,
1542        const SkPaint* paint) {
1543    bool snapOut = paint && paint->isAntiAlias();
1544
1545    if (paint && paint->getStyle() != SkPaint::kFill_Style) {
1546        float outset = paint->getStrokeWidth() * 0.5f;
1547        left -= outset;
1548        top -= outset;
1549        right += outset;
1550        bottom += outset;
1551    }
1552
1553    bool clipRequired = false;
1554    bool roundRectClipRequired = false;
1555    if (mState.calculateQuickRejectForScissor(left, top, right, bottom,
1556            &clipRequired, &roundRectClipRequired, snapOut)) {
1557        return true;
1558    }
1559
1560    // not quick rejected, so enable the scissor if clipRequired
1561    mRenderState.scissor().setEnabled(mScissorOptimizationDisabled || clipRequired);
1562    mSkipOutlineClip = !roundRectClipRequired;
1563    return false;
1564}
1565
1566void OpenGLRenderer::debugClip() {
1567#if DEBUG_CLIP_REGIONS
1568    if (!currentSnapshot()->clipRegion->isEmpty()) {
1569        SkPaint paint;
1570        paint.setColor(0x7f00ff00);
1571        drawRegionRects(*(currentSnapshot()->clipRegion, paint);
1572
1573    }
1574#endif
1575}
1576
1577///////////////////////////////////////////////////////////////////////////////
1578// Drawing commands
1579///////////////////////////////////////////////////////////////////////////////
1580
1581void OpenGLRenderer::setupDraw(bool clearLayer) {
1582    // TODO: It would be best if we could do this before quickRejectSetupScissor()
1583    //       changes the scissor test state
1584    if (clearLayer) clearLayerRegions();
1585    // Make sure setScissor & setStencil happen at the beginning of
1586    // this method
1587    if (mState.getDirtyClip()) {
1588        if (mRenderState.scissor().isEnabled()) {
1589            setScissorFromClip();
1590        }
1591
1592        setStencilFromClip();
1593    }
1594
1595    mDescription.reset();
1596
1597    mSetShaderColor = false;
1598    mColorSet = false;
1599    mColorA = mColorR = mColorG = mColorB = 0.0f;
1600    mTextureUnit = 0;
1601    mTrackDirtyRegions = true;
1602
1603    // Enable debug highlight when what we're about to draw is tested against
1604    // the stencil buffer and if stencil highlight debugging is on
1605    mDescription.hasDebugHighlight = !mCaches.debugOverdraw &&
1606            mCaches.debugStencilClip == Caches::kStencilShowHighlight &&
1607            mRenderState.stencil().isTestEnabled();
1608}
1609
1610void OpenGLRenderer::setupDrawWithTexture(bool isAlpha8) {
1611    mDescription.hasTexture = true;
1612    mDescription.hasAlpha8Texture = isAlpha8;
1613}
1614
1615void OpenGLRenderer::setupDrawWithTextureAndColor(bool isAlpha8) {
1616    mDescription.hasTexture = true;
1617    mDescription.hasColors = true;
1618    mDescription.hasAlpha8Texture = isAlpha8;
1619}
1620
1621void OpenGLRenderer::setupDrawWithExternalTexture() {
1622    mDescription.hasExternalTexture = true;
1623}
1624
1625void OpenGLRenderer::setupDrawNoTexture() {
1626    mRenderState.meshState().disableTexCoordsVertexArray();
1627}
1628
1629void OpenGLRenderer::setupDrawVertexAlpha(bool useShadowAlphaInterp) {
1630    mDescription.hasVertexAlpha = true;
1631    mDescription.useShadowAlphaInterp = useShadowAlphaInterp;
1632}
1633
1634void OpenGLRenderer::setupDrawColor(int color, int alpha) {
1635    mColorA = alpha / 255.0f;
1636    mColorR = mColorA * ((color >> 16) & 0xFF) / 255.0f;
1637    mColorG = mColorA * ((color >>  8) & 0xFF) / 255.0f;
1638    mColorB = mColorA * ((color      ) & 0xFF) / 255.0f;
1639    mColorSet = true;
1640    mSetShaderColor = mDescription.setColorModulate(mColorA);
1641}
1642
1643void OpenGLRenderer::setupDrawAlpha8Color(int color, int alpha) {
1644    mColorA = alpha / 255.0f;
1645    mColorR = mColorA * ((color >> 16) & 0xFF) / 255.0f;
1646    mColorG = mColorA * ((color >>  8) & 0xFF) / 255.0f;
1647    mColorB = mColorA * ((color      ) & 0xFF) / 255.0f;
1648    mColorSet = true;
1649    mSetShaderColor = mDescription.setAlpha8ColorModulate(mColorR, mColorG, mColorB, mColorA);
1650}
1651
1652void OpenGLRenderer::setupDrawTextGamma(const SkPaint* paint) {
1653    mCaches.fontRenderer->describe(mDescription, paint);
1654}
1655
1656void OpenGLRenderer::setupDrawColor(float r, float g, float b, float a) {
1657    mColorA = a;
1658    mColorR = r;
1659    mColorG = g;
1660    mColorB = b;
1661    mColorSet = true;
1662    mSetShaderColor = mDescription.setColorModulate(a);
1663}
1664
1665void OpenGLRenderer::setupDrawShader(const SkShader* shader) {
1666    if (shader != nullptr) {
1667        SkiaShader::describe(&mCaches, mDescription, mExtensions, *shader);
1668    }
1669}
1670
1671void OpenGLRenderer::setupDrawColorFilter(const SkColorFilter* filter) {
1672    if (filter == nullptr) {
1673        return;
1674    }
1675
1676    SkXfermode::Mode mode;
1677    if (filter->asColorMode(nullptr, &mode)) {
1678        mDescription.colorOp = ProgramDescription::kColorBlend;
1679        mDescription.colorMode = mode;
1680    } else if (filter->asColorMatrix(nullptr)) {
1681        mDescription.colorOp = ProgramDescription::kColorMatrix;
1682    }
1683}
1684
1685void OpenGLRenderer::accountForClear(SkXfermode::Mode mode) {
1686    if (mColorSet && mode == SkXfermode::kClear_Mode) {
1687        mColorA = 1.0f;
1688        mColorR = mColorG = mColorB = 0.0f;
1689        mSetShaderColor = mDescription.modulate = true;
1690    }
1691}
1692
1693void OpenGLRenderer::setupDrawBlending(const Layer* layer, bool swapSrcDst) {
1694    SkXfermode::Mode mode = layer->getMode();
1695    // When the blending mode is kClear_Mode, we need to use a modulate color
1696    // argb=1,0,0,0
1697    accountForClear(mode);
1698    // TODO: check shader blending, once we have shader drawing support for layers.
1699    bool blend = layer->isBlend()
1700            || getLayerAlpha(layer) < 1.0f
1701            || (mColorSet && mColorA < 1.0f)
1702            || PaintUtils::isBlendedColorFilter(layer->getColorFilter());
1703    chooseBlending(blend, mode, mDescription, swapSrcDst);
1704}
1705
1706void OpenGLRenderer::setupDrawBlending(const SkPaint* paint, bool blend, bool swapSrcDst) {
1707    SkXfermode::Mode mode = getXfermodeDirect(paint);
1708    // When the blending mode is kClear_Mode, we need to use a modulate color
1709    // argb=1,0,0,0
1710    accountForClear(mode);
1711    blend |= (mColorSet && mColorA < 1.0f) ||
1712            (getShader(paint) && !getShader(paint)->isOpaque()) ||
1713            PaintUtils::isBlendedColorFilter(getColorFilter(paint));
1714    chooseBlending(blend, mode, mDescription, swapSrcDst);
1715}
1716
1717void OpenGLRenderer::setupDrawProgram() {
1718    useProgram(mCaches.programCache.get(mDescription));
1719    if (mDescription.hasRoundRectClip) {
1720        // TODO: avoid doing this repeatedly, stashing state pointer in program
1721        const RoundRectClipState* state = writableSnapshot()->roundRectClipState;
1722        const Rect& innerRect = state->innerRect;
1723        glUniform4f(mCaches.currentProgram->getUniform("roundRectInnerRectLTRB"),
1724                innerRect.left, innerRect.top,
1725                innerRect.right, innerRect.bottom);
1726        glUniformMatrix4fv(mCaches.currentProgram->getUniform("roundRectInvTransform"),
1727                1, GL_FALSE, &state->matrix.data[0]);
1728
1729        // add half pixel to round out integer rect space to cover pixel centers
1730        float roundedOutRadius = state->radius + 0.5f;
1731        glUniform1f(mCaches.currentProgram->getUniform("roundRectRadius"),
1732                roundedOutRadius);
1733    }
1734}
1735
1736void OpenGLRenderer::setupDrawDirtyRegionsDisabled() {
1737    mTrackDirtyRegions = false;
1738}
1739
1740void OpenGLRenderer::setupDrawModelView(ModelViewMode mode, bool offset,
1741        float left, float top, float right, float bottom, bool ignoreTransform) {
1742    mModelViewMatrix.loadTranslate(left, top, 0.0f);
1743    if (mode == kModelViewMode_TranslateAndScale) {
1744        mModelViewMatrix.scale(right - left, bottom - top, 1.0f);
1745    }
1746
1747    bool dirty = right - left > 0.0f && bottom - top > 0.0f;
1748    const Matrix4& transformMatrix = ignoreTransform ? Matrix4::identity() : *currentTransform();
1749    mCaches.currentProgram->set(writableSnapshot()->getOrthoMatrix(),
1750            mModelViewMatrix, transformMatrix, offset);
1751    if (dirty && mTrackDirtyRegions) {
1752        if (!ignoreTransform) {
1753            dirtyLayer(left, top, right, bottom, *currentTransform());
1754        } else {
1755            dirtyLayer(left, top, right, bottom);
1756        }
1757    }
1758}
1759
1760void OpenGLRenderer::setupDrawColorUniforms(bool hasShader) {
1761    if ((mColorSet && !hasShader) || (hasShader && mSetShaderColor)) {
1762        mCaches.currentProgram->setColor(mColorR, mColorG, mColorB, mColorA);
1763    }
1764}
1765
1766void OpenGLRenderer::setupDrawPureColorUniforms() {
1767    if (mSetShaderColor) {
1768        mCaches.currentProgram->setColor(mColorR, mColorG, mColorB, mColorA);
1769    }
1770}
1771
1772void OpenGLRenderer::setupDrawShaderUniforms(const SkShader* shader, bool ignoreTransform) {
1773    if (shader == nullptr) {
1774        return;
1775    }
1776
1777    if (ignoreTransform) {
1778        // if ignoreTransform=true was passed to setupDrawModelView, undo currentTransform()
1779        // because it was built into modelView / the geometry, and the description needs to
1780        // compensate.
1781        mat4 modelViewWithoutTransform;
1782        modelViewWithoutTransform.loadInverse(*currentTransform());
1783        modelViewWithoutTransform.multiply(mModelViewMatrix);
1784        mModelViewMatrix.load(modelViewWithoutTransform);
1785    }
1786
1787    SkiaShader::setupProgram(&mCaches, mModelViewMatrix, &mTextureUnit, mExtensions, *shader);
1788}
1789
1790void OpenGLRenderer::setupDrawColorFilterUniforms(const SkColorFilter* filter) {
1791    if (nullptr == filter) {
1792        return;
1793    }
1794
1795    SkColor color;
1796    SkXfermode::Mode mode;
1797    if (filter->asColorMode(&color, &mode)) {
1798        const int alpha = SkColorGetA(color);
1799        const GLfloat a = alpha / 255.0f;
1800        const GLfloat r = a * SkColorGetR(color) / 255.0f;
1801        const GLfloat g = a * SkColorGetG(color) / 255.0f;
1802        const GLfloat b = a * SkColorGetB(color) / 255.0f;
1803        glUniform4f(mCaches.currentProgram->getUniform("colorBlend"), r, g, b, a);
1804        return;
1805    }
1806
1807    SkScalar srcColorMatrix[20];
1808    if (filter->asColorMatrix(srcColorMatrix)) {
1809
1810        float colorMatrix[16];
1811        memcpy(colorMatrix, srcColorMatrix, 4 * sizeof(float));
1812        memcpy(&colorMatrix[4], &srcColorMatrix[5], 4 * sizeof(float));
1813        memcpy(&colorMatrix[8], &srcColorMatrix[10], 4 * sizeof(float));
1814        memcpy(&colorMatrix[12], &srcColorMatrix[15], 4 * sizeof(float));
1815
1816        // Skia uses the range [0..255] for the addition vector, but we need
1817        // the [0..1] range to apply the vector in GLSL
1818        float colorVector[4];
1819        colorVector[0] = srcColorMatrix[4] / 255.0f;
1820        colorVector[1] = srcColorMatrix[9] / 255.0f;
1821        colorVector[2] = srcColorMatrix[14] / 255.0f;
1822        colorVector[3] = srcColorMatrix[19] / 255.0f;
1823
1824        glUniformMatrix4fv(mCaches.currentProgram->getUniform("colorMatrix"), 1,
1825                GL_FALSE, colorMatrix);
1826        glUniform4fv(mCaches.currentProgram->getUniform("colorMatrixVector"), 1, colorVector);
1827        return;
1828    }
1829
1830    // it is an error if we ever get here
1831}
1832
1833void OpenGLRenderer::setupDrawTextGammaUniforms() {
1834    mCaches.fontRenderer->setupProgram(mDescription, mCaches.currentProgram);
1835}
1836
1837void OpenGLRenderer::setupDrawSimpleMesh() {
1838    bool force = mRenderState.meshState().bindMeshBuffer();
1839    mRenderState.meshState().bindPositionVertexPointer(mCaches.currentProgram, force, nullptr);
1840    mRenderState.meshState().unbindIndicesBuffer();
1841}
1842
1843void OpenGLRenderer::setupDrawTexture(GLuint texture) {
1844    if (texture) mCaches.textureState().bindTexture(texture);
1845    mTextureUnit++;
1846    mRenderState.meshState().enableTexCoordsVertexArray();
1847}
1848
1849void OpenGLRenderer::setupDrawExternalTexture(GLuint texture) {
1850    mCaches.textureState().bindTexture(GL_TEXTURE_EXTERNAL_OES, texture);
1851    mTextureUnit++;
1852    mRenderState.meshState().enableTexCoordsVertexArray();
1853}
1854
1855void OpenGLRenderer::setupDrawTextureTransform() {
1856    mDescription.hasTextureTransform = true;
1857}
1858
1859void OpenGLRenderer::setupDrawTextureTransformUniforms(mat4& transform) {
1860    glUniformMatrix4fv(mCaches.currentProgram->getUniform("mainTextureTransform"), 1,
1861            GL_FALSE, &transform.data[0]);
1862}
1863
1864void OpenGLRenderer::setupDrawMesh(const GLvoid* vertices,
1865        const GLvoid* texCoords, GLuint vbo) {
1866    bool force = false;
1867    if (!vertices || vbo) {
1868        force = mRenderState.meshState().bindMeshBuffer(vbo);
1869    } else {
1870        force = mRenderState.meshState().unbindMeshBuffer();
1871    }
1872
1873    mRenderState.meshState().bindPositionVertexPointer(mCaches.currentProgram, force, vertices);
1874    if (mCaches.currentProgram->texCoords >= 0) {
1875        mRenderState.meshState().bindTexCoordsVertexPointer(mCaches.currentProgram, force, texCoords);
1876    }
1877
1878    mRenderState.meshState().unbindIndicesBuffer();
1879}
1880
1881void OpenGLRenderer::setupDrawMesh(const GLvoid* vertices,
1882        const GLvoid* texCoords, const GLvoid* colors) {
1883    bool force = mRenderState.meshState().unbindMeshBuffer();
1884    GLsizei stride = sizeof(ColorTextureVertex);
1885
1886    mRenderState.meshState().bindPositionVertexPointer(mCaches.currentProgram, force,
1887            vertices, stride);
1888    if (mCaches.currentProgram->texCoords >= 0) {
1889        mRenderState.meshState().bindTexCoordsVertexPointer(mCaches.currentProgram, force,
1890                texCoords, stride);
1891    }
1892    int slot = mCaches.currentProgram->getAttrib("colors");
1893    if (slot >= 0) {
1894        glEnableVertexAttribArray(slot);
1895        glVertexAttribPointer(slot, 4, GL_FLOAT, GL_FALSE, stride, colors);
1896    }
1897
1898    mRenderState.meshState().unbindIndicesBuffer();
1899}
1900
1901void OpenGLRenderer::setupDrawMeshIndices(const GLvoid* vertices,
1902        const GLvoid* texCoords, GLuint vbo) {
1903    bool force = false;
1904    // If vbo is != 0 we want to treat the vertices parameter as an offset inside
1905    // a VBO. However, if vertices is set to NULL and vbo == 0 then we want to
1906    // use the default VBO found in RenderState
1907    if (!vertices || vbo) {
1908        force = mRenderState.meshState().bindMeshBuffer(vbo);
1909    } else {
1910        force = mRenderState.meshState().unbindMeshBuffer();
1911    }
1912    mRenderState.meshState().bindQuadIndicesBuffer();
1913
1914    mRenderState.meshState().bindPositionVertexPointer(mCaches.currentProgram, force, vertices);
1915    if (mCaches.currentProgram->texCoords >= 0) {
1916        mRenderState.meshState().bindTexCoordsVertexPointer(mCaches.currentProgram,
1917                force, texCoords);
1918    }
1919}
1920
1921void OpenGLRenderer::setupDrawIndexedVertices(GLvoid* vertices) {
1922    bool force = mRenderState.meshState().unbindMeshBuffer();
1923    mRenderState.meshState().bindQuadIndicesBuffer();
1924    mRenderState.meshState().bindPositionVertexPointer(mCaches.currentProgram, force,
1925            vertices, kVertexStride);
1926}
1927
1928///////////////////////////////////////////////////////////////////////////////
1929// Drawing
1930///////////////////////////////////////////////////////////////////////////////
1931
1932void OpenGLRenderer::drawRenderNode(RenderNode* renderNode, Rect& dirty, int32_t replayFlags) {
1933    // All the usual checks and setup operations (quickReject, setupDraw, etc.)
1934    // will be performed by the display list itself
1935    if (renderNode && renderNode->isRenderable()) {
1936        // compute 3d ordering
1937        renderNode->computeOrdering();
1938        if (CC_UNLIKELY(mCaches.drawDeferDisabled)) {
1939            startFrame();
1940            ReplayStateStruct replayStruct(*this, dirty, replayFlags);
1941            renderNode->replay(replayStruct, 0);
1942            return;
1943        }
1944
1945        // Don't avoid overdraw when visualizing, since that makes it harder to
1946        // debug where it's coming from, and when the problem occurs.
1947        bool avoidOverdraw = !mCaches.debugOverdraw;
1948        DeferredDisplayList deferredList(mState.currentClipRect(), avoidOverdraw);
1949        DeferStateStruct deferStruct(deferredList, *this, replayFlags);
1950        renderNode->defer(deferStruct, 0);
1951
1952        flushLayers();
1953        startFrame();
1954
1955        deferredList.flush(*this, dirty);
1956    } else {
1957        // Even if there is no drawing command(Ex: invisible),
1958        // it still needs startFrame to clear buffer and start tiling.
1959        startFrame();
1960    }
1961}
1962
1963void OpenGLRenderer::drawAlphaBitmap(Texture* texture, float left, float top,
1964        const SkPaint* paint) {
1965    float x = left;
1966    float y = top;
1967
1968    texture->setWrap(GL_CLAMP_TO_EDGE, true);
1969
1970    bool ignoreTransform = false;
1971    if (currentTransform()->isPureTranslate()) {
1972        x = (int) floorf(left + currentTransform()->getTranslateX() + 0.5f);
1973        y = (int) floorf(top + currentTransform()->getTranslateY() + 0.5f);
1974        ignoreTransform = true;
1975
1976        texture->setFilter(GL_NEAREST, true);
1977    } else {
1978        texture->setFilter(getFilter(paint), true);
1979    }
1980
1981    // No need to check for a UV mapper on the texture object, only ARGB_8888
1982    // bitmaps get packed in the atlas
1983    drawAlpha8TextureMesh(x, y, x + texture->width, y + texture->height, texture->id,
1984            paint, (GLvoid*) nullptr, (GLvoid*) kMeshTextureOffset,
1985            GL_TRIANGLE_STRIP, kMeshCount, ignoreTransform);
1986}
1987
1988/**
1989 * Important note: this method is intended to draw batches of bitmaps and
1990 * will not set the scissor enable or dirty the current layer, if any.
1991 * The caller is responsible for properly dirtying the current layer.
1992 */
1993void OpenGLRenderer::drawBitmaps(const SkBitmap* bitmap, AssetAtlas::Entry* entry,
1994        int bitmapCount, TextureVertex* vertices, bool pureTranslate,
1995        const Rect& bounds, const SkPaint* paint) {
1996    mCaches.textureState().activateTexture(0);
1997    Texture* texture = entry ? entry->texture : mCaches.textureCache.get(bitmap);
1998    if (!texture) return;
1999
2000    const AutoTexture autoCleanup(texture);
2001
2002    texture->setWrap(GL_CLAMP_TO_EDGE, true);
2003    texture->setFilter(pureTranslate ? GL_NEAREST : getFilter(paint), true);
2004
2005    const float x = (int) floorf(bounds.left + 0.5f);
2006    const float y = (int) floorf(bounds.top + 0.5f);
2007    if (CC_UNLIKELY(bitmap->colorType() == kAlpha_8_SkColorType)) {
2008        drawAlpha8TextureMesh(x, y, x + bounds.getWidth(), y + bounds.getHeight(),
2009                texture->id, paint, &vertices[0].x, &vertices[0].u,
2010                GL_TRIANGLES, bitmapCount * 6, true,
2011                kModelViewMode_Translate, false);
2012    } else {
2013        drawTextureMesh(x, y, x + bounds.getWidth(), y + bounds.getHeight(),
2014                texture->id, paint, texture->blend, &vertices[0].x, &vertices[0].u,
2015                GL_TRIANGLES, bitmapCount * 6, false, true, 0,
2016                kModelViewMode_Translate, false);
2017    }
2018
2019    mDirty = true;
2020}
2021
2022void OpenGLRenderer::drawBitmap(const SkBitmap* bitmap, const SkPaint* paint) {
2023    if (quickRejectSetupScissor(0, 0, bitmap->width(), bitmap->height())) {
2024        return;
2025    }
2026
2027    mCaches.textureState().activateTexture(0);
2028    Texture* texture = getTexture(bitmap);
2029    if (!texture) return;
2030    const AutoTexture autoCleanup(texture);
2031
2032    if (CC_UNLIKELY(bitmap->colorType() == kAlpha_8_SkColorType)) {
2033        drawAlphaBitmap(texture, 0, 0, paint);
2034    } else {
2035        drawTextureRect(0, 0, bitmap->width(), bitmap->height(), texture, paint);
2036    }
2037
2038    mDirty = true;
2039}
2040
2041void OpenGLRenderer::drawBitmapMesh(const SkBitmap* bitmap, int meshWidth, int meshHeight,
2042        const float* vertices, const int* colors, const SkPaint* paint) {
2043    if (!vertices || mState.currentlyIgnored()) {
2044        return;
2045    }
2046
2047    // TODO: use quickReject on bounds from vertices
2048    mRenderState.scissor().setEnabled(true);
2049
2050    float left = FLT_MAX;
2051    float top = FLT_MAX;
2052    float right = FLT_MIN;
2053    float bottom = FLT_MIN;
2054
2055    const uint32_t count = meshWidth * meshHeight * 6;
2056
2057    std::unique_ptr<ColorTextureVertex[]> mesh(new ColorTextureVertex[count]);
2058    ColorTextureVertex* vertex = &mesh[0];
2059
2060    std::unique_ptr<int[]> tempColors;
2061    if (!colors) {
2062        uint32_t colorsCount = (meshWidth + 1) * (meshHeight + 1);
2063        tempColors.reset(new int[colorsCount]);
2064        memset(tempColors.get(), 0xff, colorsCount * sizeof(int));
2065        colors = tempColors.get();
2066    }
2067
2068    mCaches.textureState().activateTexture(0);
2069    Texture* texture = mRenderState.assetAtlas().getEntryTexture(bitmap);
2070    const UvMapper& mapper(getMapper(texture));
2071
2072    for (int32_t y = 0; y < meshHeight; y++) {
2073        for (int32_t x = 0; x < meshWidth; x++) {
2074            uint32_t i = (y * (meshWidth + 1) + x) * 2;
2075
2076            float u1 = float(x) / meshWidth;
2077            float u2 = float(x + 1) / meshWidth;
2078            float v1 = float(y) / meshHeight;
2079            float v2 = float(y + 1) / meshHeight;
2080
2081            mapper.map(u1, v1, u2, v2);
2082
2083            int ax = i + (meshWidth + 1) * 2;
2084            int ay = ax + 1;
2085            int bx = i;
2086            int by = bx + 1;
2087            int cx = i + 2;
2088            int cy = cx + 1;
2089            int dx = i + (meshWidth + 1) * 2 + 2;
2090            int dy = dx + 1;
2091
2092            ColorTextureVertex::set(vertex++, vertices[dx], vertices[dy], u2, v2, colors[dx / 2]);
2093            ColorTextureVertex::set(vertex++, vertices[ax], vertices[ay], u1, v2, colors[ax / 2]);
2094            ColorTextureVertex::set(vertex++, vertices[bx], vertices[by], u1, v1, colors[bx / 2]);
2095
2096            ColorTextureVertex::set(vertex++, vertices[dx], vertices[dy], u2, v2, colors[dx / 2]);
2097            ColorTextureVertex::set(vertex++, vertices[bx], vertices[by], u1, v1, colors[bx / 2]);
2098            ColorTextureVertex::set(vertex++, vertices[cx], vertices[cy], u2, v1, colors[cx / 2]);
2099
2100            left = fminf(left, fminf(vertices[ax], fminf(vertices[bx], vertices[cx])));
2101            top = fminf(top, fminf(vertices[ay], fminf(vertices[by], vertices[cy])));
2102            right = fmaxf(right, fmaxf(vertices[ax], fmaxf(vertices[bx], vertices[cx])));
2103            bottom = fmaxf(bottom, fmaxf(vertices[ay], fmaxf(vertices[by], vertices[cy])));
2104        }
2105    }
2106
2107    if (quickRejectSetupScissor(left, top, right, bottom)) {
2108        return;
2109    }
2110
2111    if (!texture) {
2112        texture = mCaches.textureCache.get(bitmap);
2113        if (!texture) {
2114            return;
2115        }
2116    }
2117    const AutoTexture autoCleanup(texture);
2118
2119    texture->setWrap(GL_CLAMP_TO_EDGE, true);
2120    texture->setFilter(getFilter(paint), true);
2121
2122    int alpha;
2123    SkXfermode::Mode mode;
2124    getAlphaAndMode(paint, &alpha, &mode);
2125
2126    float a = alpha / 255.0f;
2127
2128    if (hasLayer()) {
2129        dirtyLayer(left, top, right, bottom, *currentTransform());
2130    }
2131
2132    setupDraw();
2133    setupDrawWithTextureAndColor();
2134    setupDrawColor(a, a, a, a);
2135    setupDrawColorFilter(getColorFilter(paint));
2136    setupDrawBlending(paint, true);
2137    setupDrawProgram();
2138    setupDrawDirtyRegionsDisabled();
2139    setupDrawModelView(kModelViewMode_TranslateAndScale, false, 0.0f, 0.0f, 1.0f, 1.0f);
2140    setupDrawTexture(texture->id);
2141    setupDrawPureColorUniforms();
2142    setupDrawColorFilterUniforms(getColorFilter(paint));
2143    setupDrawMesh(&mesh[0].x, &mesh[0].u, &mesh[0].r);
2144
2145    glDrawArrays(GL_TRIANGLES, 0, count);
2146
2147    int slot = mCaches.currentProgram->getAttrib("colors");
2148    if (slot >= 0) {
2149        glDisableVertexAttribArray(slot);
2150    }
2151
2152    mDirty = true;
2153}
2154
2155void OpenGLRenderer::drawBitmap(const SkBitmap* bitmap,
2156         float srcLeft, float srcTop, float srcRight, float srcBottom,
2157         float dstLeft, float dstTop, float dstRight, float dstBottom,
2158         const SkPaint* paint) {
2159    if (quickRejectSetupScissor(dstLeft, dstTop, dstRight, dstBottom)) {
2160        return;
2161    }
2162
2163    mCaches.textureState().activateTexture(0);
2164    Texture* texture = getTexture(bitmap);
2165    if (!texture) return;
2166    const AutoTexture autoCleanup(texture);
2167
2168    const float width = texture->width;
2169    const float height = texture->height;
2170
2171    float u1 = fmax(0.0f, srcLeft / width);
2172    float v1 = fmax(0.0f, srcTop / height);
2173    float u2 = fmin(1.0f, srcRight / width);
2174    float v2 = fmin(1.0f, srcBottom / height);
2175
2176    getMapper(texture).map(u1, v1, u2, v2);
2177
2178    mRenderState.meshState().unbindMeshBuffer();
2179    resetDrawTextureTexCoords(u1, v1, u2, v2);
2180
2181    texture->setWrap(GL_CLAMP_TO_EDGE, true);
2182
2183    float scaleX = (dstRight - dstLeft) / (srcRight - srcLeft);
2184    float scaleY = (dstBottom - dstTop) / (srcBottom - srcTop);
2185
2186    bool scaled = scaleX != 1.0f || scaleY != 1.0f;
2187    // Apply a scale transform on the canvas only when a shader is in use
2188    // Skia handles the ratio between the dst and src rects as a scale factor
2189    // when a shader is set
2190    bool useScaleTransform = getShader(paint) && scaled;
2191    bool ignoreTransform = false;
2192
2193    if (CC_LIKELY(currentTransform()->isPureTranslate() && !useScaleTransform)) {
2194        float x = (int) floorf(dstLeft + currentTransform()->getTranslateX() + 0.5f);
2195        float y = (int) floorf(dstTop + currentTransform()->getTranslateY() + 0.5f);
2196
2197        dstRight = x + (dstRight - dstLeft);
2198        dstBottom = y + (dstBottom - dstTop);
2199
2200        dstLeft = x;
2201        dstTop = y;
2202
2203        texture->setFilter(scaled ? getFilter(paint) : GL_NEAREST, true);
2204        ignoreTransform = true;
2205    } else {
2206        texture->setFilter(getFilter(paint), true);
2207    }
2208
2209    if (CC_UNLIKELY(useScaleTransform)) {
2210        save(SkCanvas::kMatrix_SaveFlag);
2211        translate(dstLeft, dstTop);
2212        scale(scaleX, scaleY);
2213
2214        dstLeft = 0.0f;
2215        dstTop = 0.0f;
2216
2217        dstRight = srcRight - srcLeft;
2218        dstBottom = srcBottom - srcTop;
2219    }
2220
2221    if (CC_UNLIKELY(bitmap->colorType() == kAlpha_8_SkColorType)) {
2222        drawAlpha8TextureMesh(dstLeft, dstTop, dstRight, dstBottom,
2223                texture->id, paint,
2224                &mMeshVertices[0].x, &mMeshVertices[0].u,
2225                GL_TRIANGLE_STRIP, kMeshCount, ignoreTransform);
2226    } else {
2227        drawTextureMesh(dstLeft, dstTop, dstRight, dstBottom,
2228                texture->id, paint, texture->blend,
2229                &mMeshVertices[0].x, &mMeshVertices[0].u,
2230                GL_TRIANGLE_STRIP, kMeshCount, false, ignoreTransform);
2231    }
2232
2233    if (CC_UNLIKELY(useScaleTransform)) {
2234        restore();
2235    }
2236
2237    resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
2238
2239    mDirty = true;
2240}
2241
2242void OpenGLRenderer::drawPatch(const SkBitmap* bitmap, const Res_png_9patch* patch,
2243        float left, float top, float right, float bottom, const SkPaint* paint) {
2244    if (quickRejectSetupScissor(left, top, right, bottom)) {
2245        return;
2246    }
2247
2248    AssetAtlas::Entry* entry = mRenderState.assetAtlas().getEntry(bitmap);
2249    const Patch* mesh = mCaches.patchCache.get(entry, bitmap->width(), bitmap->height(),
2250            right - left, bottom - top, patch);
2251
2252    drawPatch(bitmap, mesh, entry, left, top, right, bottom, paint);
2253}
2254
2255void OpenGLRenderer::drawPatch(const SkBitmap* bitmap, const Patch* mesh,
2256        AssetAtlas::Entry* entry, float left, float top, float right, float bottom,
2257        const SkPaint* paint) {
2258    if (quickRejectSetupScissor(left, top, right, bottom)) {
2259        return;
2260    }
2261
2262    if (CC_LIKELY(mesh && mesh->verticesCount > 0)) {
2263        mCaches.textureState().activateTexture(0);
2264        Texture* texture = entry ? entry->texture : mCaches.textureCache.get(bitmap);
2265        if (!texture) return;
2266        const AutoTexture autoCleanup(texture);
2267
2268        texture->setWrap(GL_CLAMP_TO_EDGE, true);
2269        texture->setFilter(GL_LINEAR, true);
2270
2271        const bool pureTranslate = currentTransform()->isPureTranslate();
2272        // Mark the current layer dirty where we are going to draw the patch
2273        if (hasLayer() && mesh->hasEmptyQuads) {
2274            const float offsetX = left + currentTransform()->getTranslateX();
2275            const float offsetY = top + currentTransform()->getTranslateY();
2276            const size_t count = mesh->quads.size();
2277            for (size_t i = 0; i < count; i++) {
2278                const Rect& bounds = mesh->quads.itemAt(i);
2279                if (CC_LIKELY(pureTranslate)) {
2280                    const float x = (int) floorf(bounds.left + offsetX + 0.5f);
2281                    const float y = (int) floorf(bounds.top + offsetY + 0.5f);
2282                    dirtyLayer(x, y, x + bounds.getWidth(), y + bounds.getHeight());
2283                } else {
2284                    dirtyLayer(left + bounds.left, top + bounds.top,
2285                            left + bounds.right, top + bounds.bottom, *currentTransform());
2286                }
2287            }
2288        }
2289
2290        bool ignoreTransform = false;
2291        if (CC_LIKELY(pureTranslate)) {
2292            const float x = (int) floorf(left + currentTransform()->getTranslateX() + 0.5f);
2293            const float y = (int) floorf(top + currentTransform()->getTranslateY() + 0.5f);
2294
2295            right = x + right - left;
2296            bottom = y + bottom - top;
2297            left = x;
2298            top = y;
2299            ignoreTransform = true;
2300        }
2301        drawIndexedTextureMesh(left, top, right, bottom, texture->id, paint,
2302                texture->blend, (GLvoid*) mesh->offset, (GLvoid*) mesh->textureOffset,
2303                GL_TRIANGLES, mesh->indexCount, false, ignoreTransform,
2304                mCaches.patchCache.getMeshBuffer(), kModelViewMode_Translate, !mesh->hasEmptyQuads);
2305    }
2306
2307    mDirty = true;
2308}
2309
2310/**
2311 * Important note: this method is intended to draw batches of 9-patch objects and
2312 * will not set the scissor enable or dirty the current layer, if any.
2313 * The caller is responsible for properly dirtying the current layer.
2314 */
2315void OpenGLRenderer::drawPatches(const SkBitmap* bitmap, AssetAtlas::Entry* entry,
2316        TextureVertex* vertices, uint32_t indexCount, const SkPaint* paint) {
2317    mCaches.textureState().activateTexture(0);
2318    Texture* texture = entry ? entry->texture : mCaches.textureCache.get(bitmap);
2319    if (!texture) return;
2320    const AutoTexture autoCleanup(texture);
2321
2322    texture->setWrap(GL_CLAMP_TO_EDGE, true);
2323    texture->setFilter(GL_LINEAR, true);
2324
2325    drawIndexedTextureMesh(0.0f, 0.0f, 1.0f, 1.0f, texture->id, paint,
2326            texture->blend, &vertices[0].x, &vertices[0].u,
2327            GL_TRIANGLES, indexCount, false, true, 0, kModelViewMode_Translate, false);
2328
2329    mDirty = true;
2330}
2331
2332void OpenGLRenderer::drawVertexBuffer(float translateX, float translateY,
2333        const VertexBuffer& vertexBuffer, const SkPaint* paint, int displayFlags) {
2334    // not missing call to quickReject/dirtyLayer, always done at a higher level
2335    if (!vertexBuffer.getVertexCount()) {
2336        // no vertices to draw
2337        return;
2338    }
2339
2340    Rect bounds(vertexBuffer.getBounds());
2341    bounds.translate(translateX, translateY);
2342    dirtyLayer(bounds.left, bounds.top, bounds.right, bounds.bottom, *currentTransform());
2343
2344    int color = paint->getColor();
2345    bool isAA = paint->isAntiAlias();
2346
2347    setupDraw();
2348    setupDrawNoTexture();
2349    if (isAA) setupDrawVertexAlpha((displayFlags & kVertexBuffer_ShadowInterp));
2350    setupDrawColor(color, ((color >> 24) & 0xFF) * writableSnapshot()->alpha);
2351    setupDrawColorFilter(getColorFilter(paint));
2352    setupDrawShader(getShader(paint));
2353    setupDrawBlending(paint, isAA);
2354    setupDrawProgram();
2355    setupDrawModelView(kModelViewMode_Translate, (displayFlags & kVertexBuffer_Offset),
2356            translateX, translateY, 0, 0);
2357    setupDrawColorUniforms(getShader(paint));
2358    setupDrawColorFilterUniforms(getColorFilter(paint));
2359    setupDrawShaderUniforms(getShader(paint));
2360
2361    const void* vertices = vertexBuffer.getBuffer();
2362    mRenderState.meshState().unbindMeshBuffer();
2363    mRenderState.meshState().bindPositionVertexPointer(mCaches.currentProgram,
2364            true, vertices, isAA ? kAlphaVertexStride : kVertexStride);
2365    mRenderState.meshState().resetTexCoordsVertexPointer();
2366
2367    int alphaSlot = -1;
2368    if (isAA) {
2369        void* alphaCoords = ((GLbyte*) vertices) + kVertexAlphaOffset;
2370        alphaSlot = mCaches.currentProgram->getAttrib("vtxAlpha");
2371        // TODO: avoid enable/disable in back to back uses of the alpha attribute
2372        glEnableVertexAttribArray(alphaSlot);
2373        glVertexAttribPointer(alphaSlot, 1, GL_FLOAT, GL_FALSE, kAlphaVertexStride, alphaCoords);
2374    }
2375
2376    const VertexBuffer::Mode mode = vertexBuffer.getMode();
2377    if (mode == VertexBuffer::kStandard) {
2378        mRenderState.meshState().unbindIndicesBuffer();
2379        glDrawArrays(GL_TRIANGLE_STRIP, 0, vertexBuffer.getVertexCount());
2380    } else if (mode == VertexBuffer::kOnePolyRingShadow) {
2381        mRenderState.meshState().bindShadowIndicesBuffer();
2382        glDrawElements(GL_TRIANGLE_STRIP, ONE_POLY_RING_SHADOW_INDEX_COUNT,
2383                GL_UNSIGNED_SHORT, nullptr);
2384    } else if (mode == VertexBuffer::kTwoPolyRingShadow) {
2385        mRenderState.meshState().bindShadowIndicesBuffer();
2386        glDrawElements(GL_TRIANGLE_STRIP, TWO_POLY_RING_SHADOW_INDEX_COUNT,
2387                GL_UNSIGNED_SHORT, nullptr);
2388    } else if (mode == VertexBuffer::kIndices) {
2389        mRenderState.meshState().unbindIndicesBuffer();
2390        glDrawElements(GL_TRIANGLE_STRIP, vertexBuffer.getIndexCount(),
2391                GL_UNSIGNED_SHORT, vertexBuffer.getIndices());
2392    }
2393
2394    if (isAA) {
2395        glDisableVertexAttribArray(alphaSlot);
2396    }
2397
2398    mDirty = true;
2399}
2400
2401/**
2402 * Renders a convex path via tessellation. For AA paths, this function uses a similar approach to
2403 * that of AA lines in the drawLines() function.  We expand the convex path by a half pixel in
2404 * screen space in all directions. However, instead of using a fragment shader to compute the
2405 * translucency of the color from its position, we simply use a varying parameter to define how far
2406 * a given pixel is from the edge. For non-AA paths, the expansion and alpha varying are not used.
2407 *
2408 * Doesn't yet support joins, caps, or path effects.
2409 */
2410void OpenGLRenderer::drawConvexPath(const SkPath& path, const SkPaint* paint) {
2411    VertexBuffer vertexBuffer;
2412    // TODO: try clipping large paths to viewport
2413    PathTessellator::tessellatePath(path, paint, *currentTransform(), vertexBuffer);
2414    drawVertexBuffer(vertexBuffer, paint);
2415}
2416
2417/**
2418 * We create tristrips for the lines much like shape stroke tessellation, using a per-vertex alpha
2419 * and additional geometry for defining an alpha slope perimeter.
2420 *
2421 * Using GL_LINES can be difficult because the rasterization rules for those lines produces some
2422 * unexpected results, and may vary between hardware devices. Previously we used a varying-base
2423 * in-shader alpha region, but found it to be taxing on some GPUs.
2424 *
2425 * TODO: try using a fixed input buffer for non-capped lines as in text rendering. this may reduce
2426 * memory transfer by removing need for degenerate vertices.
2427 */
2428void OpenGLRenderer::drawLines(const float* points, int count, const SkPaint* paint) {
2429    if (mState.currentlyIgnored() || count < 4) return;
2430
2431    count &= ~0x3; // round down to nearest four
2432
2433    VertexBuffer buffer;
2434    PathTessellator::tessellateLines(points, count, paint, *currentTransform(), buffer);
2435    const Rect& bounds = buffer.getBounds();
2436
2437    if (quickRejectSetupScissor(bounds.left, bounds.top, bounds.right, bounds.bottom)) {
2438        return;
2439    }
2440
2441    int displayFlags = paint->isAntiAlias() ? 0 : kVertexBuffer_Offset;
2442    drawVertexBuffer(buffer, paint, displayFlags);
2443}
2444
2445void OpenGLRenderer::drawPoints(const float* points, int count, const SkPaint* paint) {
2446    if (mState.currentlyIgnored() || count < 2) return;
2447
2448    count &= ~0x1; // round down to nearest two
2449
2450    VertexBuffer buffer;
2451    PathTessellator::tessellatePoints(points, count, paint, *currentTransform(), buffer);
2452
2453    const Rect& bounds = buffer.getBounds();
2454    if (quickRejectSetupScissor(bounds.left, bounds.top, bounds.right, bounds.bottom)) {
2455        return;
2456    }
2457
2458    int displayFlags = paint->isAntiAlias() ? 0 : kVertexBuffer_Offset;
2459    drawVertexBuffer(buffer, paint, displayFlags);
2460
2461    mDirty = true;
2462}
2463
2464void OpenGLRenderer::drawColor(int color, SkXfermode::Mode mode) {
2465    // No need to check against the clip, we fill the clip region
2466    if (mState.currentlyIgnored()) return;
2467
2468    Rect clip(mState.currentClipRect());
2469    clip.snapToPixelBoundaries();
2470
2471    SkPaint paint;
2472    paint.setColor(color);
2473    paint.setXfermodeMode(mode);
2474
2475    drawColorRect(clip.left, clip.top, clip.right, clip.bottom, &paint, true);
2476
2477    mDirty = true;
2478}
2479
2480void OpenGLRenderer::drawShape(float left, float top, const PathTexture* texture,
2481        const SkPaint* paint) {
2482    if (!texture) return;
2483    const AutoTexture autoCleanup(texture);
2484
2485    const float x = left + texture->left - texture->offset;
2486    const float y = top + texture->top - texture->offset;
2487
2488    drawPathTexture(texture, x, y, paint);
2489
2490    mDirty = true;
2491}
2492
2493void OpenGLRenderer::drawRoundRect(float left, float top, float right, float bottom,
2494        float rx, float ry, const SkPaint* p) {
2495    if (mState.currentlyIgnored()
2496            || quickRejectSetupScissor(left, top, right, bottom, p)
2497            || PaintUtils::paintWillNotDraw(*p)) {
2498        return;
2499    }
2500
2501    if (p->getPathEffect() != nullptr) {
2502        mCaches.textureState().activateTexture(0);
2503        const PathTexture* texture = mCaches.pathCache.getRoundRect(
2504                right - left, bottom - top, rx, ry, p);
2505        drawShape(left, top, texture, p);
2506    } else {
2507        const VertexBuffer* vertexBuffer = mCaches.tessellationCache.getRoundRect(
2508                *currentTransform(), *p, right - left, bottom - top, rx, ry);
2509        drawVertexBuffer(left, top, *vertexBuffer, p);
2510    }
2511}
2512
2513void OpenGLRenderer::drawCircle(float x, float y, float radius, const SkPaint* p) {
2514    if (mState.currentlyIgnored()
2515            || quickRejectSetupScissor(x - radius, y - radius, x + radius, y + radius, p)
2516            || PaintUtils::paintWillNotDraw(*p)) {
2517        return;
2518    }
2519    if (p->getPathEffect() != nullptr) {
2520        mCaches.textureState().activateTexture(0);
2521        const PathTexture* texture = mCaches.pathCache.getCircle(radius, p);
2522        drawShape(x - radius, y - radius, texture, p);
2523    } else {
2524        SkPath path;
2525        if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2526            path.addCircle(x, y, radius + p->getStrokeWidth() / 2);
2527        } else {
2528            path.addCircle(x, y, radius);
2529        }
2530        drawConvexPath(path, p);
2531    }
2532}
2533
2534void OpenGLRenderer::drawOval(float left, float top, float right, float bottom,
2535        const SkPaint* p) {
2536    if (mState.currentlyIgnored()
2537            || quickRejectSetupScissor(left, top, right, bottom, p)
2538            || PaintUtils::paintWillNotDraw(*p)) {
2539        return;
2540    }
2541
2542    if (p->getPathEffect() != nullptr) {
2543        mCaches.textureState().activateTexture(0);
2544        const PathTexture* texture = mCaches.pathCache.getOval(right - left, bottom - top, p);
2545        drawShape(left, top, texture, p);
2546    } else {
2547        SkPath path;
2548        SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
2549        if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2550            rect.outset(p->getStrokeWidth() / 2, p->getStrokeWidth() / 2);
2551        }
2552        path.addOval(rect);
2553        drawConvexPath(path, p);
2554    }
2555}
2556
2557void OpenGLRenderer::drawArc(float left, float top, float right, float bottom,
2558        float startAngle, float sweepAngle, bool useCenter, const SkPaint* p) {
2559    if (mState.currentlyIgnored()
2560            || quickRejectSetupScissor(left, top, right, bottom, p)
2561            || PaintUtils::paintWillNotDraw(*p)) {
2562        return;
2563    }
2564
2565    // TODO: support fills (accounting for concavity if useCenter && sweepAngle > 180)
2566    if (p->getStyle() != SkPaint::kStroke_Style || p->getPathEffect() != nullptr || useCenter) {
2567        mCaches.textureState().activateTexture(0);
2568        const PathTexture* texture = mCaches.pathCache.getArc(right - left, bottom - top,
2569                startAngle, sweepAngle, useCenter, p);
2570        drawShape(left, top, texture, p);
2571        return;
2572    }
2573    SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
2574    if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2575        rect.outset(p->getStrokeWidth() / 2, p->getStrokeWidth() / 2);
2576    }
2577
2578    SkPath path;
2579    if (useCenter) {
2580        path.moveTo(rect.centerX(), rect.centerY());
2581    }
2582    path.arcTo(rect, startAngle, sweepAngle, !useCenter);
2583    if (useCenter) {
2584        path.close();
2585    }
2586    drawConvexPath(path, p);
2587}
2588
2589// See SkPaintDefaults.h
2590#define SkPaintDefaults_MiterLimit SkIntToScalar(4)
2591
2592void OpenGLRenderer::drawRect(float left, float top, float right, float bottom,
2593        const SkPaint* p) {
2594    if (mState.currentlyIgnored()
2595            || quickRejectSetupScissor(left, top, right, bottom, p)
2596            || PaintUtils::paintWillNotDraw(*p)) {
2597        return;
2598    }
2599
2600    if (p->getStyle() != SkPaint::kFill_Style) {
2601        // only fill style is supported by drawConvexPath, since others have to handle joins
2602        if (p->getPathEffect() != nullptr || p->getStrokeJoin() != SkPaint::kMiter_Join ||
2603                p->getStrokeMiter() != SkPaintDefaults_MiterLimit) {
2604            mCaches.textureState().activateTexture(0);
2605            const PathTexture* texture =
2606                    mCaches.pathCache.getRect(right - left, bottom - top, p);
2607            drawShape(left, top, texture, p);
2608        } else {
2609            SkPath path;
2610            SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
2611            if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
2612                rect.outset(p->getStrokeWidth() / 2, p->getStrokeWidth() / 2);
2613            }
2614            path.addRect(rect);
2615            drawConvexPath(path, p);
2616        }
2617    } else {
2618        if (p->isAntiAlias() && !currentTransform()->isSimple()) {
2619            SkPath path;
2620            path.addRect(left, top, right, bottom);
2621            drawConvexPath(path, p);
2622        } else {
2623            drawColorRect(left, top, right, bottom, p);
2624
2625            mDirty = true;
2626        }
2627    }
2628}
2629
2630void OpenGLRenderer::drawTextShadow(const SkPaint* paint, const char* text,
2631        int bytesCount, int count, const float* positions,
2632        FontRenderer& fontRenderer, int alpha, float x, float y) {
2633    mCaches.textureState().activateTexture(0);
2634
2635    TextShadow textShadow;
2636    if (!getTextShadow(paint, &textShadow)) {
2637        LOG_ALWAYS_FATAL("failed to query shadow attributes");
2638    }
2639
2640    // NOTE: The drop shadow will not perform gamma correction
2641    //       if shader-based correction is enabled
2642    mCaches.dropShadowCache.setFontRenderer(fontRenderer);
2643    const ShadowTexture* shadow = mCaches.dropShadowCache.get(
2644            paint, text, bytesCount, count, textShadow.radius, positions);
2645    // If the drop shadow exceeds the max texture size or couldn't be
2646    // allocated, skip drawing
2647    if (!shadow) return;
2648    const AutoTexture autoCleanup(shadow);
2649
2650    const float sx = x - shadow->left + textShadow.dx;
2651    const float sy = y - shadow->top + textShadow.dy;
2652
2653    const int shadowAlpha = ((textShadow.color >> 24) & 0xFF) * writableSnapshot()->alpha;
2654    if (getShader(paint)) {
2655        textShadow.color = SK_ColorWHITE;
2656    }
2657
2658    setupDraw();
2659    setupDrawWithTexture(true);
2660    setupDrawAlpha8Color(textShadow.color, shadowAlpha < 255 ? shadowAlpha : alpha);
2661    setupDrawColorFilter(getColorFilter(paint));
2662    setupDrawShader(getShader(paint));
2663    setupDrawBlending(paint, true);
2664    setupDrawProgram();
2665    setupDrawModelView(kModelViewMode_TranslateAndScale, false,
2666            sx, sy, sx + shadow->width, sy + shadow->height);
2667    setupDrawTexture(shadow->id);
2668    setupDrawPureColorUniforms();
2669    setupDrawColorFilterUniforms(getColorFilter(paint));
2670    setupDrawShaderUniforms(getShader(paint));
2671    setupDrawMesh(nullptr, (GLvoid*) kMeshTextureOffset);
2672
2673    glDrawArrays(GL_TRIANGLE_STRIP, 0, kMeshCount);
2674}
2675
2676bool OpenGLRenderer::canSkipText(const SkPaint* paint) const {
2677    float alpha = (hasTextShadow(paint) ? 1.0f : paint->getAlpha()) * currentSnapshot()->alpha;
2678    return MathUtils::isZero(alpha)
2679            && PaintUtils::getXfermode(paint->getXfermode()) == SkXfermode::kSrcOver_Mode;
2680}
2681
2682void OpenGLRenderer::drawPosText(const char* text, int bytesCount, int count,
2683        const float* positions, const SkPaint* paint) {
2684    if (text == nullptr || count == 0 || mState.currentlyIgnored() || canSkipText(paint)) {
2685        return;
2686    }
2687
2688    // NOTE: Skia does not support perspective transform on drawPosText yet
2689    if (!currentTransform()->isSimple()) {
2690        return;
2691    }
2692
2693    mRenderState.scissor().setEnabled(true);
2694
2695    float x = 0.0f;
2696    float y = 0.0f;
2697    const bool pureTranslate = currentTransform()->isPureTranslate();
2698    if (pureTranslate) {
2699        x = (int) floorf(x + currentTransform()->getTranslateX() + 0.5f);
2700        y = (int) floorf(y + currentTransform()->getTranslateY() + 0.5f);
2701    }
2702
2703    FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
2704    fontRenderer.setFont(paint, SkMatrix::I());
2705
2706    int alpha;
2707    SkXfermode::Mode mode;
2708    getAlphaAndMode(paint, &alpha, &mode);
2709
2710    if (CC_UNLIKELY(hasTextShadow(paint))) {
2711        drawTextShadow(paint, text, bytesCount, count, positions, fontRenderer,
2712                alpha, 0.0f, 0.0f);
2713    }
2714
2715    // Pick the appropriate texture filtering
2716    bool linearFilter = currentTransform()->changesBounds();
2717    if (pureTranslate && !linearFilter) {
2718        linearFilter = fabs(y - (int) y) > 0.0f || fabs(x - (int) x) > 0.0f;
2719    }
2720    fontRenderer.setTextureFiltering(linearFilter);
2721
2722    const Rect& clip(pureTranslate ? writableSnapshot()->getClipRect() : writableSnapshot()->getLocalClip());
2723    Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
2724
2725    const bool hasActiveLayer = hasLayer();
2726
2727    TextSetupFunctor functor(this, x, y, pureTranslate, alpha, mode, paint);
2728    if (fontRenderer.renderPosText(paint, &clip, text, 0, bytesCount, count, x, y,
2729            positions, hasActiveLayer ? &bounds : nullptr, &functor)) {
2730        if (hasActiveLayer) {
2731            if (!pureTranslate) {
2732                currentTransform()->mapRect(bounds);
2733            }
2734            dirtyLayerUnchecked(bounds, getRegion());
2735        }
2736    }
2737
2738    mDirty = true;
2739}
2740
2741bool OpenGLRenderer::findBestFontTransform(const mat4& transform, SkMatrix* outMatrix) const {
2742    if (CC_LIKELY(transform.isPureTranslate())) {
2743        outMatrix->setIdentity();
2744        return false;
2745    } else if (CC_UNLIKELY(transform.isPerspective())) {
2746        outMatrix->setIdentity();
2747        return true;
2748    }
2749
2750    /**
2751     * Input is a non-perspective, scaling transform. Generate a scale-only transform,
2752     * with values rounded to the nearest int.
2753     */
2754    float sx, sy;
2755    transform.decomposeScale(sx, sy);
2756    outMatrix->setScale(
2757            roundf(fmaxf(1.0f, sx)),
2758            roundf(fmaxf(1.0f, sy)));
2759    return true;
2760}
2761
2762int OpenGLRenderer::getSaveCount() const {
2763    return mState.getSaveCount();
2764}
2765
2766int OpenGLRenderer::save(int flags) {
2767    return mState.save(flags);
2768}
2769
2770void OpenGLRenderer::restore() {
2771    return mState.restore();
2772}
2773
2774void OpenGLRenderer::restoreToCount(int saveCount) {
2775    return mState.restoreToCount(saveCount);
2776}
2777
2778void OpenGLRenderer::translate(float dx, float dy, float dz) {
2779    return mState.translate(dx, dy, dz);
2780}
2781
2782void OpenGLRenderer::rotate(float degrees) {
2783    return mState.rotate(degrees);
2784}
2785
2786void OpenGLRenderer::scale(float sx, float sy) {
2787    return mState.scale(sx, sy);
2788}
2789
2790void OpenGLRenderer::skew(float sx, float sy) {
2791    return mState.skew(sx, sy);
2792}
2793
2794void OpenGLRenderer::setMatrix(const Matrix4& matrix) {
2795    mState.setMatrix(matrix);
2796}
2797
2798void OpenGLRenderer::concatMatrix(const Matrix4& matrix) {
2799    mState.concatMatrix(matrix);
2800}
2801
2802bool OpenGLRenderer::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {
2803    return mState.clipRect(left, top, right, bottom, op);
2804}
2805
2806bool OpenGLRenderer::clipPath(const SkPath* path, SkRegion::Op op) {
2807    return mState.clipPath(path, op);
2808}
2809
2810bool OpenGLRenderer::clipRegion(const SkRegion* region, SkRegion::Op op) {
2811    return mState.clipRegion(region, op);
2812}
2813
2814void OpenGLRenderer::setClippingOutline(LinearAllocator& allocator, const Outline* outline) {
2815    mState.setClippingOutline(allocator, outline);
2816}
2817
2818void OpenGLRenderer::setClippingRoundRect(LinearAllocator& allocator,
2819        const Rect& rect, float radius, bool highPriority) {
2820    mState.setClippingRoundRect(allocator, rect, radius, highPriority);
2821}
2822
2823void OpenGLRenderer::drawText(const char* text, int bytesCount, int count, float x, float y,
2824        const float* positions, const SkPaint* paint, float totalAdvance, const Rect& bounds,
2825        DrawOpMode drawOpMode) {
2826
2827    if (drawOpMode == kDrawOpMode_Immediate) {
2828        // The checks for corner-case ignorable text and quick rejection is only done for immediate
2829        // drawing as ops from DeferredDisplayList are already filtered for these
2830        if (text == nullptr || count == 0 || mState.currentlyIgnored() || canSkipText(paint) ||
2831                quickRejectSetupScissor(bounds)) {
2832            return;
2833        }
2834    }
2835
2836    const float oldX = x;
2837    const float oldY = y;
2838
2839    const mat4& transform = *currentTransform();
2840    const bool pureTranslate = transform.isPureTranslate();
2841
2842    if (CC_LIKELY(pureTranslate)) {
2843        x = (int) floorf(x + transform.getTranslateX() + 0.5f);
2844        y = (int) floorf(y + transform.getTranslateY() + 0.5f);
2845    }
2846
2847    int alpha;
2848    SkXfermode::Mode mode;
2849    getAlphaAndMode(paint, &alpha, &mode);
2850
2851    FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
2852
2853    if (CC_UNLIKELY(hasTextShadow(paint))) {
2854        fontRenderer.setFont(paint, SkMatrix::I());
2855        drawTextShadow(paint, text, bytesCount, count, positions, fontRenderer,
2856                alpha, oldX, oldY);
2857    }
2858
2859    const bool hasActiveLayer = hasLayer();
2860
2861    // We only pass a partial transform to the font renderer. That partial
2862    // matrix defines how glyphs are rasterized. Typically we want glyphs
2863    // to be rasterized at their final size on screen, which means the partial
2864    // matrix needs to take the scale factor into account.
2865    // When a partial matrix is used to transform glyphs during rasterization,
2866    // the mesh is generated with the inverse transform (in the case of scale,
2867    // the mesh is generated at 1.0 / scale for instance.) This allows us to
2868    // apply the full transform matrix at draw time in the vertex shader.
2869    // Applying the full matrix in the shader is the easiest way to handle
2870    // rotation and perspective and allows us to always generated quads in the
2871    // font renderer which greatly simplifies the code, clipping in particular.
2872    SkMatrix fontTransform;
2873    bool linearFilter = findBestFontTransform(transform, &fontTransform)
2874            || fabs(y - (int) y) > 0.0f
2875            || fabs(x - (int) x) > 0.0f;
2876    fontRenderer.setFont(paint, fontTransform);
2877    fontRenderer.setTextureFiltering(linearFilter);
2878
2879    // TODO: Implement better clipping for scaled/rotated text
2880    const Rect* clip = !pureTranslate ? nullptr : &mState.currentClipRect();
2881    Rect layerBounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
2882
2883    bool status;
2884    TextSetupFunctor functor(this, x, y, pureTranslate, alpha, mode, paint);
2885
2886    // don't call issuedrawcommand, do it at end of batch
2887    bool forceFinish = (drawOpMode != kDrawOpMode_Defer);
2888    if (CC_UNLIKELY(paint->getTextAlign() != SkPaint::kLeft_Align)) {
2889        SkPaint paintCopy(*paint);
2890        paintCopy.setTextAlign(SkPaint::kLeft_Align);
2891        status = fontRenderer.renderPosText(&paintCopy, clip, text, 0, bytesCount, count, x, y,
2892                positions, hasActiveLayer ? &layerBounds : nullptr, &functor, forceFinish);
2893    } else {
2894        status = fontRenderer.renderPosText(paint, clip, text, 0, bytesCount, count, x, y,
2895                positions, hasActiveLayer ? &layerBounds : nullptr, &functor, forceFinish);
2896    }
2897
2898    if ((status || drawOpMode != kDrawOpMode_Immediate) && hasActiveLayer) {
2899        if (!pureTranslate) {
2900            transform.mapRect(layerBounds);
2901        }
2902        dirtyLayerUnchecked(layerBounds, getRegion());
2903    }
2904
2905    drawTextDecorations(totalAdvance, oldX, oldY, paint);
2906
2907    mDirty = true;
2908}
2909
2910void OpenGLRenderer::drawTextOnPath(const char* text, int bytesCount, int count,
2911        const SkPath* path, float hOffset, float vOffset, const SkPaint* paint) {
2912    if (text == nullptr || count == 0 || mState.currentlyIgnored() || canSkipText(paint)) {
2913        return;
2914    }
2915
2916    // TODO: avoid scissor by calculating maximum bounds using path bounds + font metrics
2917    mRenderState.scissor().setEnabled(true);
2918
2919    FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
2920    fontRenderer.setFont(paint, SkMatrix::I());
2921    fontRenderer.setTextureFiltering(true);
2922
2923    int alpha;
2924    SkXfermode::Mode mode;
2925    getAlphaAndMode(paint, &alpha, &mode);
2926    TextSetupFunctor functor(this, 0.0f, 0.0f, false, alpha, mode, paint);
2927
2928    const Rect* clip = &writableSnapshot()->getLocalClip();
2929    Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
2930
2931    const bool hasActiveLayer = hasLayer();
2932
2933    if (fontRenderer.renderTextOnPath(paint, clip, text, 0, bytesCount, count, path,
2934            hOffset, vOffset, hasActiveLayer ? &bounds : nullptr, &functor)) {
2935        if (hasActiveLayer) {
2936            currentTransform()->mapRect(bounds);
2937            dirtyLayerUnchecked(bounds, getRegion());
2938        }
2939    }
2940
2941    mDirty = true;
2942}
2943
2944void OpenGLRenderer::drawPath(const SkPath* path, const SkPaint* paint) {
2945    if (mState.currentlyIgnored()) return;
2946
2947    mCaches.textureState().activateTexture(0);
2948
2949    const PathTexture* texture = mCaches.pathCache.get(path, paint);
2950    if (!texture) return;
2951    const AutoTexture autoCleanup(texture);
2952
2953    const float x = texture->left - texture->offset;
2954    const float y = texture->top - texture->offset;
2955
2956    drawPathTexture(texture, x, y, paint);
2957    mDirty = true;
2958}
2959
2960void OpenGLRenderer::drawLayer(Layer* layer, float x, float y) {
2961    if (!layer) {
2962        return;
2963    }
2964
2965    mat4* transform = nullptr;
2966    if (layer->isTextureLayer()) {
2967        transform = &layer->getTransform();
2968        if (!transform->isIdentity()) {
2969            save(SkCanvas::kMatrix_SaveFlag);
2970            concatMatrix(*transform);
2971        }
2972    }
2973
2974    bool clipRequired = false;
2975    const bool rejected = mState.calculateQuickRejectForScissor(
2976            x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight(),
2977            &clipRequired, nullptr, false);
2978
2979    if (rejected) {
2980        if (transform && !transform->isIdentity()) {
2981            restore();
2982        }
2983        return;
2984    }
2985
2986    EVENT_LOGD("drawLayer," RECT_STRING ", clipRequired %d", x, y,
2987            x + layer->layer.getWidth(), y + layer->layer.getHeight(), clipRequired);
2988
2989    updateLayer(layer, true);
2990
2991    mRenderState.scissor().setEnabled(mScissorOptimizationDisabled || clipRequired);
2992    mCaches.textureState().activateTexture(0);
2993
2994    if (CC_LIKELY(!layer->region.isEmpty())) {
2995        if (layer->region.isRect()) {
2996            DRAW_DOUBLE_STENCIL_IF(!layer->hasDrawnSinceUpdate,
2997                    composeLayerRect(layer, layer->regionRect));
2998        } else if (layer->mesh) {
2999
3000            const float a = getLayerAlpha(layer);
3001            setupDraw();
3002            setupDrawWithTexture();
3003            setupDrawColor(a, a, a, a);
3004            setupDrawColorFilter(layer->getColorFilter());
3005            setupDrawBlending(layer);
3006            setupDrawProgram();
3007            setupDrawPureColorUniforms();
3008            setupDrawColorFilterUniforms(layer->getColorFilter());
3009            setupDrawTexture(layer->getTexture());
3010            if (CC_LIKELY(currentTransform()->isPureTranslate())) {
3011                int tx = (int) floorf(x + currentTransform()->getTranslateX() + 0.5f);
3012                int ty = (int) floorf(y + currentTransform()->getTranslateY() + 0.5f);
3013
3014                layer->setFilter(GL_NEAREST);
3015                setupDrawModelView(kModelViewMode_Translate, false, tx, ty,
3016                        tx + layer->layer.getWidth(), ty + layer->layer.getHeight(), true);
3017            } else {
3018                layer->setFilter(GL_LINEAR);
3019                setupDrawModelView(kModelViewMode_Translate, false, x, y,
3020                        x + layer->layer.getWidth(), y + layer->layer.getHeight());
3021            }
3022
3023            TextureVertex* mesh = &layer->mesh[0];
3024            GLsizei elementsCount = layer->meshElementCount;
3025
3026            while (elementsCount > 0) {
3027                GLsizei drawCount = min(elementsCount, (GLsizei) kMaxNumberOfQuads * 6);
3028
3029                setupDrawMeshIndices(&mesh[0].x, &mesh[0].u);
3030                DRAW_DOUBLE_STENCIL_IF(!layer->hasDrawnSinceUpdate,
3031                        glDrawElements(GL_TRIANGLES, drawCount, GL_UNSIGNED_SHORT, nullptr));
3032
3033                elementsCount -= drawCount;
3034                // Though there are 4 vertices in a quad, we use 6 indices per
3035                // quad to draw with GL_TRIANGLES
3036                mesh += (drawCount / 6) * 4;
3037            }
3038
3039#if DEBUG_LAYERS_AS_REGIONS
3040            drawRegionRectsDebug(layer->region);
3041#endif
3042        }
3043
3044        if (layer->debugDrawUpdate) {
3045            layer->debugDrawUpdate = false;
3046
3047            SkPaint paint;
3048            paint.setColor(0x7f00ff00);
3049            drawColorRect(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight(), &paint);
3050        }
3051    }
3052    layer->hasDrawnSinceUpdate = true;
3053
3054    if (transform && !transform->isIdentity()) {
3055        restore();
3056    }
3057
3058    mDirty = true;
3059}
3060
3061///////////////////////////////////////////////////////////////////////////////
3062// Draw filters
3063///////////////////////////////////////////////////////////////////////////////
3064void OpenGLRenderer::setDrawFilter(SkDrawFilter* filter) {
3065    // We should never get here since we apply the draw filter when stashing
3066    // the paints in the DisplayList.
3067    LOG_ALWAYS_FATAL("OpenGLRenderer does not directly support DrawFilters");
3068}
3069
3070///////////////////////////////////////////////////////////////////////////////
3071// Drawing implementation
3072///////////////////////////////////////////////////////////////////////////////
3073
3074Texture* OpenGLRenderer::getTexture(const SkBitmap* bitmap) {
3075    Texture* texture = mRenderState.assetAtlas().getEntryTexture(bitmap);
3076    if (!texture) {
3077        return mCaches.textureCache.get(bitmap);
3078    }
3079    return texture;
3080}
3081
3082void OpenGLRenderer::drawPathTexture(const PathTexture* texture,
3083        float x, float y, const SkPaint* paint) {
3084    if (quickRejectSetupScissor(x, y, x + texture->width, y + texture->height)) {
3085        return;
3086    }
3087
3088    int alpha;
3089    SkXfermode::Mode mode;
3090    getAlphaAndMode(paint, &alpha, &mode);
3091
3092    setupDraw();
3093    setupDrawWithTexture(true);
3094    setupDrawAlpha8Color(paint->getColor(), alpha);
3095    setupDrawColorFilter(getColorFilter(paint));
3096    setupDrawShader(getShader(paint));
3097    setupDrawBlending(paint, true);
3098    setupDrawProgram();
3099    setupDrawModelView(kModelViewMode_TranslateAndScale, false,
3100            x, y, x + texture->width, y + texture->height);
3101    setupDrawTexture(texture->id);
3102    setupDrawPureColorUniforms();
3103    setupDrawColorFilterUniforms(getColorFilter(paint));
3104    setupDrawShaderUniforms(getShader(paint));
3105    setupDrawMesh(nullptr, (GLvoid*) kMeshTextureOffset);
3106
3107    glDrawArrays(GL_TRIANGLE_STRIP, 0, kMeshCount);
3108}
3109
3110// Same values used by Skia
3111#define kStdStrikeThru_Offset   (-6.0f / 21.0f)
3112#define kStdUnderline_Offset    (1.0f / 9.0f)
3113#define kStdUnderline_Thickness (1.0f / 18.0f)
3114
3115void OpenGLRenderer::drawTextDecorations(float underlineWidth, float x, float y,
3116        const SkPaint* paint) {
3117    // Handle underline and strike-through
3118    uint32_t flags = paint->getFlags();
3119    if (flags & (SkPaint::kUnderlineText_Flag | SkPaint::kStrikeThruText_Flag)) {
3120        SkPaint paintCopy(*paint);
3121
3122        if (CC_LIKELY(underlineWidth > 0.0f)) {
3123            const float textSize = paintCopy.getTextSize();
3124            const float strokeWidth = fmax(textSize * kStdUnderline_Thickness, 1.0f);
3125
3126            const float left = x;
3127            float top = 0.0f;
3128
3129            int linesCount = 0;
3130            if (flags & SkPaint::kUnderlineText_Flag) linesCount++;
3131            if (flags & SkPaint::kStrikeThruText_Flag) linesCount++;
3132
3133            const int pointsCount = 4 * linesCount;
3134            float points[pointsCount];
3135            int currentPoint = 0;
3136
3137            if (flags & SkPaint::kUnderlineText_Flag) {
3138                top = y + textSize * kStdUnderline_Offset;
3139                points[currentPoint++] = left;
3140                points[currentPoint++] = top;
3141                points[currentPoint++] = left + underlineWidth;
3142                points[currentPoint++] = top;
3143            }
3144
3145            if (flags & SkPaint::kStrikeThruText_Flag) {
3146                top = y + textSize * kStdStrikeThru_Offset;
3147                points[currentPoint++] = left;
3148                points[currentPoint++] = top;
3149                points[currentPoint++] = left + underlineWidth;
3150                points[currentPoint++] = top;
3151            }
3152
3153            paintCopy.setStrokeWidth(strokeWidth);
3154
3155            drawLines(&points[0], pointsCount, &paintCopy);
3156        }
3157    }
3158}
3159
3160void OpenGLRenderer::drawRects(const float* rects, int count, const SkPaint* paint) {
3161    if (mState.currentlyIgnored()) {
3162        return;
3163    }
3164
3165    drawColorRects(rects, count, paint, false, true, true);
3166}
3167
3168void OpenGLRenderer::drawShadow(float casterAlpha,
3169        const VertexBuffer* ambientShadowVertexBuffer, const VertexBuffer* spotShadowVertexBuffer) {
3170    if (mState.currentlyIgnored()) return;
3171
3172    // TODO: use quickRejectWithScissor. For now, always force enable scissor.
3173    mRenderState.scissor().setEnabled(true);
3174
3175    SkPaint paint;
3176    paint.setAntiAlias(true); // want to use AlphaVertex
3177
3178    // The caller has made sure casterAlpha > 0.
3179    float ambientShadowAlpha = mAmbientShadowAlpha;
3180    if (CC_UNLIKELY(mCaches.propertyAmbientShadowStrength >= 0)) {
3181        ambientShadowAlpha = mCaches.propertyAmbientShadowStrength;
3182    }
3183    if (ambientShadowVertexBuffer && ambientShadowAlpha > 0) {
3184        paint.setARGB(casterAlpha * ambientShadowAlpha, 0, 0, 0);
3185        drawVertexBuffer(*ambientShadowVertexBuffer, &paint, kVertexBuffer_ShadowInterp);
3186    }
3187
3188    float spotShadowAlpha = mSpotShadowAlpha;
3189    if (CC_UNLIKELY(mCaches.propertySpotShadowStrength >= 0)) {
3190        spotShadowAlpha = mCaches.propertySpotShadowStrength;
3191    }
3192    if (spotShadowVertexBuffer && spotShadowAlpha > 0) {
3193        paint.setARGB(casterAlpha * spotShadowAlpha, 0, 0, 0);
3194        drawVertexBuffer(*spotShadowVertexBuffer, &paint, kVertexBuffer_ShadowInterp);
3195    }
3196
3197    mDirty=true;
3198}
3199
3200void OpenGLRenderer::drawColorRects(const float* rects, int count, const SkPaint* paint,
3201        bool ignoreTransform, bool dirty, bool clip) {
3202    if (count == 0) {
3203        return;
3204    }
3205
3206    int color = paint->getColor();
3207    // If a shader is set, preserve only the alpha
3208    if (getShader(paint)) {
3209        color |= 0x00ffffff;
3210    }
3211
3212    float left = FLT_MAX;
3213    float top = FLT_MAX;
3214    float right = FLT_MIN;
3215    float bottom = FLT_MIN;
3216
3217    Vertex mesh[count];
3218    Vertex* vertex = mesh;
3219
3220    for (int index = 0; index < count; index += 4) {
3221        float l = rects[index + 0];
3222        float t = rects[index + 1];
3223        float r = rects[index + 2];
3224        float b = rects[index + 3];
3225
3226        Vertex::set(vertex++, l, t);
3227        Vertex::set(vertex++, r, t);
3228        Vertex::set(vertex++, l, b);
3229        Vertex::set(vertex++, r, b);
3230
3231        left = fminf(left, l);
3232        top = fminf(top, t);
3233        right = fmaxf(right, r);
3234        bottom = fmaxf(bottom, b);
3235    }
3236
3237    if (clip && quickRejectSetupScissor(left, top, right, bottom)) {
3238        return;
3239    }
3240
3241    setupDraw();
3242    setupDrawNoTexture();
3243    setupDrawColor(color, ((color >> 24) & 0xFF) * currentSnapshot()->alpha);
3244    setupDrawShader(getShader(paint));
3245    setupDrawColorFilter(getColorFilter(paint));
3246    setupDrawBlending(paint);
3247    setupDrawProgram();
3248    setupDrawDirtyRegionsDisabled();
3249    setupDrawModelView(kModelViewMode_Translate, false,
3250            0.0f, 0.0f, 0.0f, 0.0f, ignoreTransform);
3251    setupDrawColorUniforms(getShader(paint));
3252    setupDrawShaderUniforms(getShader(paint));
3253    setupDrawColorFilterUniforms(getColorFilter(paint));
3254
3255    if (dirty && hasLayer()) {
3256        dirtyLayer(left, top, right, bottom, *currentTransform());
3257    }
3258
3259    issueIndexedQuadDraw(&mesh[0], count / 4);
3260
3261    mDirty = true;
3262}
3263
3264void OpenGLRenderer::drawColorRect(float left, float top, float right, float bottom,
3265        const SkPaint* paint, bool ignoreTransform) {
3266    int color = paint->getColor();
3267    // If a shader is set, preserve only the alpha
3268    if (getShader(paint)) {
3269        color |= 0x00ffffff;
3270    }
3271
3272    setupDraw();
3273    setupDrawNoTexture();
3274    setupDrawColor(color, ((color >> 24) & 0xFF) * currentSnapshot()->alpha);
3275    setupDrawShader(getShader(paint));
3276    setupDrawColorFilter(getColorFilter(paint));
3277    setupDrawBlending(paint);
3278    setupDrawProgram();
3279    setupDrawModelView(kModelViewMode_TranslateAndScale, false,
3280            left, top, right, bottom, ignoreTransform);
3281    setupDrawColorUniforms(getShader(paint));
3282    setupDrawShaderUniforms(getShader(paint), ignoreTransform);
3283    setupDrawColorFilterUniforms(getColorFilter(paint));
3284    setupDrawSimpleMesh();
3285
3286    glDrawArrays(GL_TRIANGLE_STRIP, 0, kMeshCount);
3287}
3288
3289void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom,
3290        Texture* texture, const SkPaint* paint) {
3291    texture->setWrap(GL_CLAMP_TO_EDGE, true);
3292
3293    GLvoid* vertices = (GLvoid*) nullptr;
3294    GLvoid* texCoords = (GLvoid*) kMeshTextureOffset;
3295
3296    if (texture->uvMapper) {
3297        vertices = &mMeshVertices[0].x;
3298        texCoords = &mMeshVertices[0].u;
3299
3300        Rect uvs(0.0f, 0.0f, 1.0f, 1.0f);
3301        texture->uvMapper->map(uvs);
3302
3303        resetDrawTextureTexCoords(uvs.left, uvs.top, uvs.right, uvs.bottom);
3304    }
3305
3306    if (CC_LIKELY(currentTransform()->isPureTranslate())) {
3307        const float x = (int) floorf(left + currentTransform()->getTranslateX() + 0.5f);
3308        const float y = (int) floorf(top + currentTransform()->getTranslateY() + 0.5f);
3309
3310        texture->setFilter(GL_NEAREST, true);
3311        drawTextureMesh(x, y, x + texture->width, y + texture->height, texture->id,
3312                paint, texture->blend, vertices, texCoords,
3313                GL_TRIANGLE_STRIP, kMeshCount, false, true);
3314    } else {
3315        texture->setFilter(getFilter(paint), true);
3316        drawTextureMesh(left, top, right, bottom, texture->id, paint,
3317                texture->blend, vertices, texCoords, GL_TRIANGLE_STRIP, kMeshCount);
3318    }
3319
3320    if (texture->uvMapper) {
3321        resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
3322    }
3323}
3324
3325void OpenGLRenderer::drawTextureMesh(float left, float top, float right, float bottom,
3326        GLuint texture, const SkPaint* paint, bool blend,
3327        GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
3328        bool swapSrcDst, bool ignoreTransform, GLuint vbo,
3329        ModelViewMode modelViewMode, bool dirty) {
3330
3331    int a;
3332    SkXfermode::Mode mode;
3333    getAlphaAndMode(paint, &a, &mode);
3334    const float alpha = a / 255.0f;
3335
3336    setupDraw();
3337    setupDrawWithTexture();
3338    setupDrawColor(alpha, alpha, alpha, alpha);
3339    setupDrawColorFilter(getColorFilter(paint));
3340    setupDrawBlending(paint, blend, swapSrcDst);
3341    setupDrawProgram();
3342    if (!dirty) setupDrawDirtyRegionsDisabled();
3343    setupDrawModelView(modelViewMode, false, left, top, right, bottom, ignoreTransform);
3344    setupDrawTexture(texture);
3345    setupDrawPureColorUniforms();
3346    setupDrawColorFilterUniforms(getColorFilter(paint));
3347    setupDrawMesh(vertices, texCoords, vbo);
3348
3349    glDrawArrays(drawMode, 0, elementsCount);
3350}
3351
3352void OpenGLRenderer::drawIndexedTextureMesh(float left, float top, float right, float bottom,
3353        GLuint texture, const SkPaint* paint, bool blend,
3354        GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
3355        bool swapSrcDst, bool ignoreTransform, GLuint vbo,
3356        ModelViewMode modelViewMode, bool dirty) {
3357
3358    int a;
3359    SkXfermode::Mode mode;
3360    getAlphaAndMode(paint, &a, &mode);
3361    const float alpha = a / 255.0f;
3362
3363    setupDraw();
3364    setupDrawWithTexture();
3365    setupDrawColor(alpha, alpha, alpha, alpha);
3366    setupDrawColorFilter(getColorFilter(paint));
3367    setupDrawBlending(paint, blend, swapSrcDst);
3368    setupDrawProgram();
3369    if (!dirty) setupDrawDirtyRegionsDisabled();
3370    setupDrawModelView(modelViewMode, false, left, top, right, bottom, ignoreTransform);
3371    setupDrawTexture(texture);
3372    setupDrawPureColorUniforms();
3373    setupDrawColorFilterUniforms(getColorFilter(paint));
3374    setupDrawMeshIndices(vertices, texCoords, vbo);
3375
3376    glDrawElements(drawMode, elementsCount, GL_UNSIGNED_SHORT, nullptr);
3377}
3378
3379void OpenGLRenderer::drawAlpha8TextureMesh(float left, float top, float right, float bottom,
3380        GLuint texture, const SkPaint* paint,
3381        GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
3382        bool ignoreTransform, ModelViewMode modelViewMode, bool dirty) {
3383
3384    int color = paint != nullptr ? paint->getColor() : 0;
3385    int alpha;
3386    SkXfermode::Mode mode;
3387    getAlphaAndMode(paint, &alpha, &mode);
3388
3389    setupDraw();
3390    setupDrawWithTexture(true);
3391    if (paint != nullptr) {
3392        setupDrawAlpha8Color(color, alpha);
3393    }
3394    setupDrawColorFilter(getColorFilter(paint));
3395    setupDrawShader(getShader(paint));
3396    setupDrawBlending(paint, true);
3397    setupDrawProgram();
3398    if (!dirty) setupDrawDirtyRegionsDisabled();
3399    setupDrawModelView(modelViewMode, false, left, top, right, bottom, ignoreTransform);
3400    setupDrawTexture(texture);
3401    setupDrawPureColorUniforms();
3402    setupDrawColorFilterUniforms(getColorFilter(paint));
3403    setupDrawShaderUniforms(getShader(paint), ignoreTransform);
3404    setupDrawMesh(vertices, texCoords);
3405
3406    glDrawArrays(drawMode, 0, elementsCount);
3407}
3408
3409void OpenGLRenderer::chooseBlending(bool blend, SkXfermode::Mode mode,
3410        ProgramDescription& description, bool swapSrcDst) {
3411
3412    if (writableSnapshot()->roundRectClipState != nullptr /*&& !mSkipOutlineClip*/) {
3413        blend = true;
3414        mDescription.hasRoundRectClip = true;
3415    }
3416    mSkipOutlineClip = true;
3417
3418    blend = blend || mode != SkXfermode::kSrcOver_Mode;
3419
3420    if (blend) {
3421        // These blend modes are not supported by OpenGL directly and have
3422        // to be implemented using shaders. Since the shader will perform
3423        // the blending, turn blending off here
3424        // If the blend mode cannot be implemented using shaders, fall
3425        // back to the default SrcOver blend mode instead
3426        if (CC_UNLIKELY(mode > SkXfermode::kScreen_Mode)) {
3427            if (CC_UNLIKELY(mExtensions.hasFramebufferFetch())) {
3428                description.framebufferMode = mode;
3429                description.swapSrcDst = swapSrcDst;
3430
3431                mRenderState.blend().disable();
3432                return;
3433            } else {
3434                mode = SkXfermode::kSrcOver_Mode;
3435            }
3436        }
3437        mRenderState.blend().enable(mode, swapSrcDst);
3438    } else {
3439        mRenderState.blend().disable();
3440    }
3441}
3442
3443bool OpenGLRenderer::useProgram(Program* program) {
3444    if (!program->isInUse()) {
3445        if (mCaches.currentProgram != nullptr) mCaches.currentProgram->remove();
3446        program->use();
3447        mCaches.currentProgram = program;
3448        return false;
3449    }
3450    return true;
3451}
3452
3453void OpenGLRenderer::resetDrawTextureTexCoords(float u1, float v1, float u2, float v2) {
3454    TextureVertex* v = &mMeshVertices[0];
3455    TextureVertex::setUV(v++, u1, v1);
3456    TextureVertex::setUV(v++, u2, v1);
3457    TextureVertex::setUV(v++, u1, v2);
3458    TextureVertex::setUV(v++, u2, v2);
3459}
3460
3461void OpenGLRenderer::getAlphaAndMode(const SkPaint* paint, int* alpha,
3462        SkXfermode::Mode* mode) const {
3463    getAlphaAndModeDirect(paint, alpha,  mode);
3464    if (mDrawModifiers.mOverrideLayerAlpha < 1.0f) {
3465        // if drawing a layer, ignore the paint's alpha
3466        *alpha = mDrawModifiers.mOverrideLayerAlpha * 255;
3467    }
3468    *alpha *= currentSnapshot()->alpha;
3469}
3470
3471float OpenGLRenderer::getLayerAlpha(const Layer* layer) const {
3472    float alpha;
3473    if (mDrawModifiers.mOverrideLayerAlpha < 1.0f) {
3474        alpha = mDrawModifiers.mOverrideLayerAlpha;
3475    } else {
3476        alpha = layer->getAlpha() / 255.0f;
3477    }
3478    return alpha * currentSnapshot()->alpha;
3479}
3480
3481}; // namespace uirenderer
3482}; // namespace android
3483