OpenGLRenderer.cpp revision 80911b851764b073310fd0bffdf4a7db0d8fdd0b 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define LOG_TAG "OpenGLRenderer"
18
19#include <stdlib.h>
20#include <stdint.h>
21#include <sys/types.h>
22
23#include <SkCanvas.h>
24#include <SkTypeface.h>
25
26#include <utils/Log.h>
27#include <utils/StopWatch.h>
28
29#include <ui/Rect.h>
30
31#include "OpenGLRenderer.h"
32#include "DisplayListRenderer.h"
33#include "Vector.h"
34
35namespace android {
36namespace uirenderer {
37
38///////////////////////////////////////////////////////////////////////////////
39// Defines
40///////////////////////////////////////////////////////////////////////////////
41
42#define RAD_TO_DEG (180.0f / 3.14159265f)
43#define MIN_ANGLE 0.001f
44
45// TODO: This should be set in properties
46#define ALPHA_THRESHOLD (0x7f / PANEL_BIT_DEPTH)
47
48///////////////////////////////////////////////////////////////////////////////
49// Globals
50///////////////////////////////////////////////////////////////////////////////
51
52/**
53 * Structure mapping Skia xfermodes to OpenGL blending factors.
54 */
55struct Blender {
56    SkXfermode::Mode mode;
57    GLenum src;
58    GLenum dst;
59}; // struct Blender
60
61// In this array, the index of each Blender equals the value of the first
62// entry. For instance, gBlends[1] == gBlends[SkXfermode::kSrc_Mode]
63static const Blender gBlends[] = {
64    { SkXfermode::kClear_Mode,   GL_ZERO,                 GL_ZERO },
65    { SkXfermode::kSrc_Mode,     GL_ONE,                  GL_ZERO },
66    { SkXfermode::kDst_Mode,     GL_ZERO,                 GL_ONE },
67    { SkXfermode::kSrcOver_Mode, GL_ONE,                  GL_ONE_MINUS_SRC_ALPHA },
68    { SkXfermode::kDstOver_Mode, GL_ONE_MINUS_DST_ALPHA,  GL_ONE },
69    { SkXfermode::kSrcIn_Mode,   GL_DST_ALPHA,            GL_ZERO },
70    { SkXfermode::kDstIn_Mode,   GL_ZERO,                 GL_SRC_ALPHA },
71    { SkXfermode::kSrcOut_Mode,  GL_ONE_MINUS_DST_ALPHA,  GL_ZERO },
72    { SkXfermode::kDstOut_Mode,  GL_ZERO,                 GL_ONE_MINUS_SRC_ALPHA },
73    { SkXfermode::kSrcATop_Mode, GL_DST_ALPHA,            GL_ONE_MINUS_SRC_ALPHA },
74    { SkXfermode::kDstATop_Mode, GL_ONE_MINUS_DST_ALPHA,  GL_SRC_ALPHA },
75    { SkXfermode::kXor_Mode,     GL_ONE_MINUS_DST_ALPHA,  GL_ONE_MINUS_SRC_ALPHA }
76};
77
78// This array contains the swapped version of each SkXfermode. For instance
79// this array's SrcOver blending mode is actually DstOver. You can refer to
80// createLayer() for more information on the purpose of this array.
81static const Blender gBlendsSwap[] = {
82    { SkXfermode::kClear_Mode,   GL_ZERO,                 GL_ZERO },
83    { SkXfermode::kSrc_Mode,     GL_ZERO,                 GL_ONE },
84    { SkXfermode::kDst_Mode,     GL_ONE,                  GL_ZERO },
85    { SkXfermode::kSrcOver_Mode, GL_ONE_MINUS_DST_ALPHA,  GL_ONE },
86    { SkXfermode::kDstOver_Mode, GL_ONE,                  GL_ONE_MINUS_SRC_ALPHA },
87    { SkXfermode::kSrcIn_Mode,   GL_ZERO,                 GL_SRC_ALPHA },
88    { SkXfermode::kDstIn_Mode,   GL_DST_ALPHA,            GL_ZERO },
89    { SkXfermode::kSrcOut_Mode,  GL_ZERO,                 GL_ONE_MINUS_SRC_ALPHA },
90    { SkXfermode::kDstOut_Mode,  GL_ONE_MINUS_DST_ALPHA,  GL_ZERO },
91    { SkXfermode::kSrcATop_Mode, GL_ONE_MINUS_DST_ALPHA,  GL_SRC_ALPHA },
92    { SkXfermode::kDstATop_Mode, GL_DST_ALPHA,            GL_ONE_MINUS_SRC_ALPHA },
93    { SkXfermode::kXor_Mode,     GL_ONE_MINUS_DST_ALPHA,  GL_ONE_MINUS_SRC_ALPHA }
94};
95
96static const GLenum gTextureUnits[] = {
97    GL_TEXTURE0,
98    GL_TEXTURE1,
99    GL_TEXTURE2
100};
101
102///////////////////////////////////////////////////////////////////////////////
103// Constructors/destructor
104///////////////////////////////////////////////////////////////////////////////
105
106OpenGLRenderer::OpenGLRenderer(): mCaches(Caches::getInstance()) {
107    mShader = NULL;
108    mColorFilter = NULL;
109    mHasShadow = false;
110
111    memcpy(mMeshVertices, gMeshVertices, sizeof(gMeshVertices));
112
113    mFirstSnapshot = new Snapshot;
114}
115
116OpenGLRenderer::~OpenGLRenderer() {
117    // The context has already been destroyed at this point, do not call
118    // GL APIs. All GL state should be kept in Caches.h
119}
120
121///////////////////////////////////////////////////////////////////////////////
122// Setup
123///////////////////////////////////////////////////////////////////////////////
124
125void OpenGLRenderer::setViewport(int width, int height) {
126    glViewport(0, 0, width, height);
127    mOrthoMatrix.loadOrtho(0, width, height, 0, -1, 1);
128
129    mWidth = width;
130    mHeight = height;
131
132    mFirstSnapshot->height = height;
133    mFirstSnapshot->viewport.set(0, 0, width, height);
134
135    mDirtyClip = false;
136}
137
138void OpenGLRenderer::prepare(bool opaque) {
139    prepareDirty(0.0f, 0.0f, mWidth, mHeight, opaque);
140}
141
142void OpenGLRenderer::prepareDirty(float left, float top, float right, float bottom, bool opaque) {
143    mCaches.clearGarbage();
144
145    mSnapshot = new Snapshot(mFirstSnapshot,
146            SkCanvas::kMatrix_SaveFlag | SkCanvas::kClip_SaveFlag);
147    mSnapshot->fbo = getTargetFbo();
148
149    mSaveCount = 1;
150
151    glViewport(0, 0, mWidth, mHeight);
152
153    glDisable(GL_DITHER);
154
155    glEnable(GL_SCISSOR_TEST);
156    glScissor(left, mSnapshot->height - bottom, right - left, bottom - top);
157    mSnapshot->setClip(left, top, right, bottom);
158
159    if (!opaque) {
160        glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
161        glClear(GL_COLOR_BUFFER_BIT);
162    }
163}
164
165void OpenGLRenderer::finish() {
166#if DEBUG_OPENGL
167    GLenum status = GL_NO_ERROR;
168    while ((status = glGetError()) != GL_NO_ERROR) {
169        LOGD("GL error from OpenGLRenderer: 0x%x", status);
170        switch (status) {
171            case GL_OUT_OF_MEMORY:
172                LOGE("  OpenGLRenderer is out of memory!");
173                break;
174        }
175    }
176#endif
177#if DEBUG_MEMORY_USAGE
178    mCaches.dumpMemoryUsage();
179#else
180    if (mCaches.getDebugLevel() & kDebugMemory) {
181        mCaches.dumpMemoryUsage();
182    }
183#endif
184}
185
186void OpenGLRenderer::interrupt() {
187    if (mCaches.currentProgram) {
188        if (mCaches.currentProgram->isInUse()) {
189            mCaches.currentProgram->remove();
190            mCaches.currentProgram = NULL;
191        }
192    }
193    mCaches.unbindMeshBuffer();
194}
195
196void OpenGLRenderer::resume() {
197    glViewport(0, 0, mSnapshot->viewport.getWidth(), mSnapshot->viewport.getHeight());
198
199    glEnable(GL_SCISSOR_TEST);
200    dirtyClip();
201
202    glDisable(GL_DITHER);
203
204    glBindFramebuffer(GL_FRAMEBUFFER, getTargetFbo());
205    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
206
207    mCaches.blend = true;
208    glEnable(GL_BLEND);
209    glBlendFunc(mCaches.lastSrcMode, mCaches.lastDstMode);
210    glBlendEquation(GL_FUNC_ADD);
211}
212
213bool OpenGLRenderer::callDrawGLFunction(Functor *functor, Rect& dirty) {
214    interrupt();
215    if (mDirtyClip) {
216        setScissorFromClip();
217    }
218
219    Rect clip(*mSnapshot->clipRect);
220    clip.snapToPixelBoundaries();
221
222#if RENDER_LAYERS_AS_REGIONS
223    // Since we don't know what the functor will draw, let's dirty
224    // tne entire clip region
225    if (hasLayer()) {
226        dirtyLayerUnchecked(clip, getRegion());
227    }
228#endif
229
230    struct {
231        // Input: current clip rect
232        int clipLeft;
233        int clipTop;
234        int clipRight;
235        int clipBottom;
236
237        // Output: dirty region to redraw
238        float dirtyLeft;
239        float dirtyTop;
240        float dirtyRight;
241        float dirtyBottom;
242    } constraints;
243
244    constraints.clipLeft = clip.left;
245    constraints.clipTop = clip.top;
246    constraints.clipRight = clip.right;
247    constraints.clipBottom = clip.bottom;
248
249    status_t result = (*functor)(0, &constraints);
250
251    if (result != 0) {
252        Rect localDirty(constraints.dirtyLeft, constraints.dirtyTop,
253                constraints.dirtyRight, constraints.dirtyBottom);
254        dirty.unionWith(localDirty);
255    }
256
257    resume();
258    return result != 0;
259}
260
261///////////////////////////////////////////////////////////////////////////////
262// State management
263///////////////////////////////////////////////////////////////////////////////
264
265int OpenGLRenderer::getSaveCount() const {
266    return mSaveCount;
267}
268
269int OpenGLRenderer::save(int flags) {
270    return saveSnapshot(flags);
271}
272
273void OpenGLRenderer::restore() {
274    if (mSaveCount > 1) {
275        restoreSnapshot();
276    }
277}
278
279void OpenGLRenderer::restoreToCount(int saveCount) {
280    if (saveCount < 1) saveCount = 1;
281
282    while (mSaveCount > saveCount) {
283        restoreSnapshot();
284    }
285}
286
287int OpenGLRenderer::saveSnapshot(int flags) {
288    mSnapshot = new Snapshot(mSnapshot, flags);
289    return mSaveCount++;
290}
291
292bool OpenGLRenderer::restoreSnapshot() {
293    bool restoreClip = mSnapshot->flags & Snapshot::kFlagClipSet;
294    bool restoreLayer = mSnapshot->flags & Snapshot::kFlagIsLayer;
295    bool restoreOrtho = mSnapshot->flags & Snapshot::kFlagDirtyOrtho;
296
297    sp<Snapshot> current = mSnapshot;
298    sp<Snapshot> previous = mSnapshot->previous;
299
300    if (restoreOrtho) {
301        Rect& r = previous->viewport;
302        glViewport(r.left, r.top, r.right, r.bottom);
303        mOrthoMatrix.load(current->orthoMatrix);
304    }
305
306    mSaveCount--;
307    mSnapshot = previous;
308
309    if (restoreClip) {
310        dirtyClip();
311    }
312
313    if (restoreLayer) {
314        composeLayer(current, previous);
315    }
316
317    return restoreClip;
318}
319
320///////////////////////////////////////////////////////////////////////////////
321// Layers
322///////////////////////////////////////////////////////////////////////////////
323
324int OpenGLRenderer::saveLayer(float left, float top, float right, float bottom,
325        SkPaint* p, int flags) {
326    const GLuint previousFbo = mSnapshot->fbo;
327    const int count = saveSnapshot(flags);
328
329    if (!mSnapshot->isIgnored()) {
330        int alpha = 255;
331        SkXfermode::Mode mode;
332
333        if (p) {
334            alpha = p->getAlpha();
335            if (!mCaches.extensions.hasFramebufferFetch()) {
336                const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode);
337                if (!isMode) {
338                    // Assume SRC_OVER
339                    mode = SkXfermode::kSrcOver_Mode;
340                }
341            } else {
342                mode = getXfermode(p->getXfermode());
343            }
344        } else {
345            mode = SkXfermode::kSrcOver_Mode;
346        }
347
348        createLayer(mSnapshot, left, top, right, bottom, alpha, mode, flags, previousFbo);
349    }
350
351    return count;
352}
353
354int OpenGLRenderer::saveLayerAlpha(float left, float top, float right, float bottom,
355        int alpha, int flags) {
356    if (alpha >= 255 - ALPHA_THRESHOLD) {
357        return saveLayer(left, top, right, bottom, NULL, flags);
358    } else {
359        SkPaint paint;
360        paint.setAlpha(alpha);
361        return saveLayer(left, top, right, bottom, &paint, flags);
362    }
363}
364
365/**
366 * Layers are viewed by Skia are slightly different than layers in image editing
367 * programs (for instance.) When a layer is created, previously created layers
368 * and the frame buffer still receive every drawing command. For instance, if a
369 * layer is created and a shape intersecting the bounds of the layers and the
370 * framebuffer is draw, the shape will be drawn on both (unless the layer was
371 * created with the SkCanvas::kClipToLayer_SaveFlag flag.)
372 *
373 * A way to implement layers is to create an FBO for each layer, backed by an RGBA
374 * texture. Unfortunately, this is inefficient as it requires every primitive to
375 * be drawn n + 1 times, where n is the number of active layers. In practice this
376 * means, for every primitive:
377 *   - Switch active frame buffer
378 *   - Change viewport, clip and projection matrix
379 *   - Issue the drawing
380 *
381 * Switching rendering target n + 1 times per drawn primitive is extremely costly.
382 * To avoid this, layers are implemented in a different way here, at least in the
383 * general case. FBOs are used, as an optimization, when the "clip to layer" flag
384 * is set. When this flag is set we can redirect all drawing operations into a
385 * single FBO.
386 *
387 * This implementation relies on the frame buffer being at least RGBA 8888. When
388 * a layer is created, only a texture is created, not an FBO. The content of the
389 * frame buffer contained within the layer's bounds is copied into this texture
390 * using glCopyTexImage2D(). The layer's region is then cleared(1) in the frame
391 * buffer and drawing continues as normal. This technique therefore treats the
392 * frame buffer as a scratch buffer for the layers.
393 *
394 * To compose the layers back onto the frame buffer, each layer texture
395 * (containing the original frame buffer data) is drawn as a simple quad over
396 * the frame buffer. The trick is that the quad is set as the composition
397 * destination in the blending equation, and the frame buffer becomes the source
398 * of the composition.
399 *
400 * Drawing layers with an alpha value requires an extra step before composition.
401 * An empty quad is drawn over the layer's region in the frame buffer. This quad
402 * is drawn with the rgba color (0,0,0,alpha). The alpha value offered by the
403 * quad is used to multiply the colors in the frame buffer. This is achieved by
404 * changing the GL blend functions for the GL_FUNC_ADD blend equation to
405 * GL_ZERO, GL_SRC_ALPHA.
406 *
407 * Because glCopyTexImage2D() can be slow, an alternative implementation might
408 * be use to draw a single clipped layer. The implementation described above
409 * is correct in every case.
410 *
411 * (1) The frame buffer is actually not cleared right away. To allow the GPU
412 *     to potentially optimize series of calls to glCopyTexImage2D, the frame
413 *     buffer is left untouched until the first drawing operation. Only when
414 *     something actually gets drawn are the layers regions cleared.
415 */
416bool OpenGLRenderer::createLayer(sp<Snapshot> snapshot, float left, float top,
417        float right, float bottom, int alpha, SkXfermode::Mode mode,
418        int flags, GLuint previousFbo) {
419    LAYER_LOGD("Requesting layer %.2fx%.2f", right - left, bottom - top);
420    LAYER_LOGD("Layer cache size = %d", mCaches.layerCache.getSize());
421
422    const bool fboLayer = flags & SkCanvas::kClipToLayer_SaveFlag;
423
424    // Window coordinates of the layer
425    Rect bounds(left, top, right, bottom);
426    if (!fboLayer) {
427        mSnapshot->transform->mapRect(bounds);
428
429        // Layers only make sense if they are in the framebuffer's bounds
430        if (bounds.intersect(*snapshot->clipRect)) {
431            // We cannot work with sub-pixels in this case
432            bounds.snapToPixelBoundaries();
433
434            // When the layer is not an FBO, we may use glCopyTexImage so we
435            // need to make sure the layer does not extend outside the bounds
436            // of the framebuffer
437            if (!bounds.intersect(snapshot->previous->viewport)) {
438                bounds.setEmpty();
439            }
440        } else {
441            bounds.setEmpty();
442        }
443    }
444
445    if (bounds.isEmpty() || bounds.getWidth() > mCaches.maxTextureSize ||
446            bounds.getHeight() > mCaches.maxTextureSize) {
447        snapshot->empty = fboLayer;
448    } else {
449        snapshot->invisible = snapshot->invisible || (alpha <= ALPHA_THRESHOLD && fboLayer);
450    }
451
452    // Bail out if we won't draw in this snapshot
453    if (snapshot->invisible || snapshot->empty) {
454        return false;
455    }
456
457    glActiveTexture(gTextureUnits[0]);
458    Layer* layer = mCaches.layerCache.get(bounds.getWidth(), bounds.getHeight());
459    if (!layer) {
460        return false;
461    }
462
463    layer->mode = mode;
464    layer->alpha = alpha;
465    layer->layer.set(bounds);
466    layer->texCoords.set(0.0f, bounds.getHeight() / float(layer->height),
467            bounds.getWidth() / float(layer->width), 0.0f);
468    layer->colorFilter = mColorFilter;
469
470    // Save the layer in the snapshot
471    snapshot->flags |= Snapshot::kFlagIsLayer;
472    snapshot->layer = layer;
473
474    if (fboLayer) {
475        return createFboLayer(layer, bounds, snapshot, previousFbo);
476    } else {
477        // Copy the framebuffer into the layer
478        glBindTexture(GL_TEXTURE_2D, layer->texture);
479        if (!bounds.isEmpty()) {
480            if (layer->empty) {
481                glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, bounds.left,
482                        snapshot->height - bounds.bottom, layer->width, layer->height, 0);
483                layer->empty = false;
484            } else {
485                glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, bounds.left,
486                        snapshot->height - bounds.bottom, bounds.getWidth(), bounds.getHeight());
487            }
488
489            // Clear the framebuffer where the layer will draw
490            glScissor(bounds.left, mSnapshot->height - bounds.bottom,
491                    bounds.getWidth(), bounds.getHeight());
492            glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
493            glClear(GL_COLOR_BUFFER_BIT);
494
495            dirtyClip();
496        }
497    }
498
499    return true;
500}
501
502bool OpenGLRenderer::createFboLayer(Layer* layer, Rect& bounds, sp<Snapshot> snapshot,
503        GLuint previousFbo) {
504    layer->fbo = mCaches.fboCache.get();
505
506#if RENDER_LAYERS_AS_REGIONS
507    snapshot->region = &snapshot->layer->region;
508    snapshot->flags |= Snapshot::kFlagFboTarget;
509#endif
510
511    Rect clip(bounds);
512    snapshot->transform->mapRect(clip);
513    clip.intersect(*snapshot->clipRect);
514    clip.snapToPixelBoundaries();
515    clip.intersect(snapshot->previous->viewport);
516
517    mat4 inverse;
518    inverse.loadInverse(*mSnapshot->transform);
519
520    inverse.mapRect(clip);
521    clip.snapToPixelBoundaries();
522    clip.intersect(bounds);
523    clip.translate(-bounds.left, -bounds.top);
524
525    snapshot->flags |= Snapshot::kFlagIsFboLayer;
526    snapshot->fbo = layer->fbo;
527    snapshot->resetTransform(-bounds.left, -bounds.top, 0.0f);
528    snapshot->resetClip(clip.left, clip.top, clip.right, clip.bottom);
529    snapshot->viewport.set(0.0f, 0.0f, bounds.getWidth(), bounds.getHeight());
530    snapshot->height = bounds.getHeight();
531    snapshot->flags |= Snapshot::kFlagDirtyOrtho;
532    snapshot->orthoMatrix.load(mOrthoMatrix);
533
534    // Bind texture to FBO
535    glBindFramebuffer(GL_FRAMEBUFFER, layer->fbo);
536    glBindTexture(GL_TEXTURE_2D, layer->texture);
537
538    // Initialize the texture if needed
539    if (layer->empty) {
540        layer->empty = false;
541        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, layer->width, layer->height, 0,
542                GL_RGBA, GL_UNSIGNED_BYTE, NULL);
543    }
544
545    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
546            layer->texture, 0);
547
548#if DEBUG_LAYERS_AS_REGIONS
549    GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
550    if (status != GL_FRAMEBUFFER_COMPLETE) {
551        LOGE("Framebuffer incomplete (GL error code 0x%x)", status);
552
553        glBindFramebuffer(GL_FRAMEBUFFER, previousFbo);
554        glDeleteTextures(1, &layer->texture);
555        mCaches.fboCache.put(layer->fbo);
556
557        delete layer;
558
559        return false;
560    }
561#endif
562
563    // Clear the FBO, expand the clear region by 1 to get nice bilinear filtering
564    glScissor(clip.left - 1.0f, bounds.getHeight() - clip.bottom - 1.0f,
565            clip.getWidth() + 2.0f, clip.getHeight() + 2.0f);
566    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
567    glClear(GL_COLOR_BUFFER_BIT);
568
569    dirtyClip();
570
571    // Change the ortho projection
572    glViewport(0, 0, bounds.getWidth(), bounds.getHeight());
573    mOrthoMatrix.loadOrtho(0.0f, bounds.getWidth(), bounds.getHeight(), 0.0f, -1.0f, 1.0f);
574
575    return true;
576}
577
578/**
579 * Read the documentation of createLayer() before doing anything in this method.
580 */
581void OpenGLRenderer::composeLayer(sp<Snapshot> current, sp<Snapshot> previous) {
582    if (!current->layer) {
583        LOGE("Attempting to compose a layer that does not exist");
584        return;
585    }
586
587    const bool fboLayer = current->flags & Snapshot::kFlagIsFboLayer;
588
589    if (fboLayer) {
590        // Unbind current FBO and restore previous one
591        glBindFramebuffer(GL_FRAMEBUFFER, previous->fbo);
592    }
593
594    Layer* layer = current->layer;
595    const Rect& rect = layer->layer;
596
597    if (!fboLayer && layer->alpha < 255) {
598        drawColorRect(rect.left, rect.top, rect.right, rect.bottom,
599                layer->alpha << 24, SkXfermode::kDstIn_Mode, true);
600        // Required below, composeLayerRect() will divide by 255
601        layer->alpha = 255;
602    }
603
604    mCaches.unbindMeshBuffer();
605
606    glActiveTexture(gTextureUnits[0]);
607
608    // When the layer is stored in an FBO, we can save a bit of fillrate by
609    // drawing only the dirty region
610    if (fboLayer) {
611        dirtyLayer(rect.left, rect.top, rect.right, rect.bottom, *previous->transform);
612        if (layer->colorFilter) {
613            setupColorFilter(layer->colorFilter);
614        }
615        composeLayerRegion(layer, rect);
616        if (layer->colorFilter) {
617            resetColorFilter();
618        }
619    } else {
620        if (!rect.isEmpty()) {
621            dirtyLayer(rect.left, rect.top, rect.right, rect.bottom);
622            composeLayerRect(layer, rect, true);
623        }
624    }
625
626    if (fboLayer) {
627        // Detach the texture from the FBO
628        glBindFramebuffer(GL_FRAMEBUFFER, current->fbo);
629        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 0, 0);
630        glBindFramebuffer(GL_FRAMEBUFFER, previous->fbo);
631
632        // Put the FBO name back in the cache, if it doesn't fit, it will be destroyed
633        mCaches.fboCache.put(current->fbo);
634    }
635
636    dirtyClip();
637
638    // Failing to add the layer to the cache should happen only if the layer is too large
639    if (!mCaches.layerCache.put(layer)) {
640        LAYER_LOGD("Deleting layer");
641        glDeleteTextures(1, &layer->texture);
642        delete layer;
643    }
644}
645
646void OpenGLRenderer::composeLayerRect(Layer* layer, const Rect& rect, bool swap) {
647    const Rect& texCoords = layer->texCoords;
648    resetDrawTextureTexCoords(texCoords.left, texCoords.top, texCoords.right, texCoords.bottom);
649
650    drawTextureMesh(rect.left, rect.top, rect.right, rect.bottom, layer->texture,
651            layer->alpha / 255.0f, layer->mode, layer->blend, &mMeshVertices[0].position[0],
652            &mMeshVertices[0].texture[0], GL_TRIANGLE_STRIP, gMeshCount, swap, swap);
653
654    resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
655}
656
657void OpenGLRenderer::composeLayerRegion(Layer* layer, const Rect& rect) {
658#if RENDER_LAYERS_AS_REGIONS
659#if RENDER_LAYERS_RECT_AS_RECT
660    if (layer->region.isRect()) {
661        composeLayerRect(layer, rect);
662        layer->region.clear();
663        return;
664    }
665#endif
666
667    if (!layer->region.isEmpty()) {
668        size_t count;
669        const android::Rect* rects = layer->region.getArray(&count);
670
671        const float alpha = layer->alpha / 255.0f;
672        const float texX = 1.0f / float(layer->width);
673        const float texY = 1.0f / float(layer->height);
674        const float height = rect.getHeight();
675
676        TextureVertex* mesh = mCaches.getRegionMesh();
677        GLsizei numQuads = 0;
678
679        setupDraw();
680        setupDrawWithTexture();
681        setupDrawColor(alpha, alpha, alpha, alpha);
682        setupDrawColorFilter();
683        setupDrawBlending(layer->blend || layer->alpha < 255, layer->mode, false);
684        setupDrawProgram();
685        setupDrawDirtyRegionsDisabled();
686        setupDrawPureColorUniforms();
687        setupDrawColorFilterUniforms();
688        setupDrawTexture(layer->texture);
689        setupDrawModelViewTranslate(rect.left, rect.top, rect.right, rect.bottom);
690        setupDrawMesh(&mesh[0].position[0], &mesh[0].texture[0]);
691
692        for (size_t i = 0; i < count; i++) {
693            const android::Rect* r = &rects[i];
694
695            const float u1 = r->left * texX;
696            const float v1 = (height - r->top) * texY;
697            const float u2 = r->right * texX;
698            const float v2 = (height - r->bottom) * texY;
699
700            // TODO: Reject quads outside of the clip
701            TextureVertex::set(mesh++, r->left, r->top, u1, v1);
702            TextureVertex::set(mesh++, r->right, r->top, u2, v1);
703            TextureVertex::set(mesh++, r->left, r->bottom, u1, v2);
704            TextureVertex::set(mesh++, r->right, r->bottom, u2, v2);
705
706            numQuads++;
707
708            if (numQuads >= REGION_MESH_QUAD_COUNT) {
709                glDrawElements(GL_TRIANGLES, numQuads * 6, GL_UNSIGNED_SHORT, NULL);
710                numQuads = 0;
711                mesh = mCaches.getRegionMesh();
712            }
713        }
714
715        if (numQuads > 0) {
716            glDrawElements(GL_TRIANGLES, numQuads * 6, GL_UNSIGNED_SHORT, NULL);
717        }
718
719        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
720        finishDrawTexture();
721
722#if DEBUG_LAYERS_AS_REGIONS
723        drawRegionRects(layer->region);
724#endif
725
726        layer->region.clear();
727    }
728#else
729    composeLayerRect(layer, rect);
730#endif
731}
732
733void OpenGLRenderer::drawRegionRects(const Region& region) {
734#if DEBUG_LAYERS_AS_REGIONS
735    size_t count;
736    const android::Rect* rects = region.getArray(&count);
737
738    uint32_t colors[] = {
739            0x7fff0000, 0x7f00ff00,
740            0x7f0000ff, 0x7fff00ff,
741    };
742
743    int offset = 0;
744    int32_t top = rects[0].top;
745
746    for (size_t i = 0; i < count; i++) {
747        if (top != rects[i].top) {
748            offset ^= 0x2;
749            top = rects[i].top;
750        }
751
752        Rect r(rects[i].left, rects[i].top, rects[i].right, rects[i].bottom);
753        drawColorRect(r.left, r.top, r.right, r.bottom, colors[offset + (i & 0x1)],
754                SkXfermode::kSrcOver_Mode);
755    }
756#endif
757}
758
759void OpenGLRenderer::dirtyLayer(const float left, const float top,
760        const float right, const float bottom, const mat4 transform) {
761#if RENDER_LAYERS_AS_REGIONS
762    if (hasLayer()) {
763        Rect bounds(left, top, right, bottom);
764        transform.mapRect(bounds);
765        dirtyLayerUnchecked(bounds, getRegion());
766    }
767#endif
768}
769
770void OpenGLRenderer::dirtyLayer(const float left, const float top,
771        const float right, const float bottom) {
772#if RENDER_LAYERS_AS_REGIONS
773    if (hasLayer()) {
774        Rect bounds(left, top, right, bottom);
775        dirtyLayerUnchecked(bounds, getRegion());
776    }
777#endif
778}
779
780void OpenGLRenderer::dirtyLayerUnchecked(Rect& bounds, Region* region) {
781#if RENDER_LAYERS_AS_REGIONS
782    if (bounds.intersect(*mSnapshot->clipRect)) {
783        bounds.snapToPixelBoundaries();
784        android::Rect dirty(bounds.left, bounds.top, bounds.right, bounds.bottom);
785        if (!dirty.isEmpty()) {
786            region->orSelf(dirty);
787        }
788    }
789#endif
790}
791
792///////////////////////////////////////////////////////////////////////////////
793// Transforms
794///////////////////////////////////////////////////////////////////////////////
795
796void OpenGLRenderer::translate(float dx, float dy) {
797    mSnapshot->transform->translate(dx, dy, 0.0f);
798}
799
800void OpenGLRenderer::rotate(float degrees) {
801    mSnapshot->transform->rotate(degrees, 0.0f, 0.0f, 1.0f);
802}
803
804void OpenGLRenderer::scale(float sx, float sy) {
805    mSnapshot->transform->scale(sx, sy, 1.0f);
806}
807
808void OpenGLRenderer::skew(float sx, float sy) {
809    mSnapshot->transform->skew(sx, sy);
810}
811
812void OpenGLRenderer::setMatrix(SkMatrix* matrix) {
813    mSnapshot->transform->load(*matrix);
814}
815
816const float* OpenGLRenderer::getMatrix() const {
817    if (mSnapshot->fbo != 0) {
818        return &mSnapshot->transform->data[0];
819    }
820    return &mIdentity.data[0];
821}
822
823void OpenGLRenderer::getMatrix(SkMatrix* matrix) {
824    mSnapshot->transform->copyTo(*matrix);
825}
826
827void OpenGLRenderer::concatMatrix(SkMatrix* matrix) {
828    SkMatrix transform;
829    mSnapshot->transform->copyTo(transform);
830    transform.preConcat(*matrix);
831    mSnapshot->transform->load(transform);
832}
833
834///////////////////////////////////////////////////////////////////////////////
835// Clipping
836///////////////////////////////////////////////////////////////////////////////
837
838void OpenGLRenderer::setScissorFromClip() {
839    Rect clip(*mSnapshot->clipRect);
840    clip.snapToPixelBoundaries();
841    glScissor(clip.left, mSnapshot->height - clip.bottom, clip.getWidth(), clip.getHeight());
842    mDirtyClip = false;
843}
844
845const Rect& OpenGLRenderer::getClipBounds() {
846    return mSnapshot->getLocalClip();
847}
848
849bool OpenGLRenderer::quickReject(float left, float top, float right, float bottom) {
850    if (mSnapshot->isIgnored()) {
851        return true;
852    }
853
854    Rect r(left, top, right, bottom);
855    mSnapshot->transform->mapRect(r);
856    r.snapToPixelBoundaries();
857
858    Rect clipRect(*mSnapshot->clipRect);
859    clipRect.snapToPixelBoundaries();
860
861    return !clipRect.intersects(r);
862}
863
864bool OpenGLRenderer::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {
865    bool clipped = mSnapshot->clip(left, top, right, bottom, op);
866    if (clipped) {
867        dirtyClip();
868    }
869    return !mSnapshot->clipRect->isEmpty();
870}
871
872///////////////////////////////////////////////////////////////////////////////
873// Drawing commands
874///////////////////////////////////////////////////////////////////////////////
875
876void OpenGLRenderer::setupDraw() {
877    if (mDirtyClip) {
878        setScissorFromClip();
879    }
880    mDescription.reset();
881    mSetShaderColor = false;
882    mColorSet = false;
883    mColorA = mColorR = mColorG = mColorB = 0.0f;
884    mTextureUnit = 0;
885    mTrackDirtyRegions = true;
886    mTexCoordsSlot = -1;
887}
888
889void OpenGLRenderer::setupDrawWithTexture(bool isAlpha8) {
890    mDescription.hasTexture = true;
891    mDescription.hasAlpha8Texture = isAlpha8;
892}
893
894void OpenGLRenderer::setupDrawColor(int color) {
895    setupDrawColor(color, (color >> 24) & 0xFF);
896}
897
898void OpenGLRenderer::setupDrawColor(int color, int alpha) {
899    mColorA = alpha / 255.0f;
900    const float a = mColorA / 255.0f;
901    mColorR = a * ((color >> 16) & 0xFF);
902    mColorG = a * ((color >>  8) & 0xFF);
903    mColorB = a * ((color      ) & 0xFF);
904    mColorSet = true;
905    mSetShaderColor = mDescription.setColor(mColorR, mColorG, mColorB, mColorA);
906}
907
908void OpenGLRenderer::setupDrawAlpha8Color(int color, int alpha) {
909    mColorA = alpha / 255.0f;
910    const float a = mColorA / 255.0f;
911    mColorR = a * ((color >> 16) & 0xFF);
912    mColorG = a * ((color >>  8) & 0xFF);
913    mColorB = a * ((color      ) & 0xFF);
914    mColorSet = true;
915    mSetShaderColor = mDescription.setAlpha8Color(mColorR, mColorG, mColorB, mColorA);
916}
917
918void OpenGLRenderer::setupDrawColor(float r, float g, float b, float a) {
919    mColorA = a;
920    mColorR = r;
921    mColorG = g;
922    mColorB = b;
923    mColorSet = true;
924    mSetShaderColor = mDescription.setColor(r, g, b, a);
925}
926
927void OpenGLRenderer::setupDrawAlpha8Color(float r, float g, float b, float a) {
928    mColorA = a;
929    mColorR = r;
930    mColorG = g;
931    mColorB = b;
932    mColorSet = true;
933    mSetShaderColor = mDescription.setAlpha8Color(r, g, b, a);
934}
935
936void OpenGLRenderer::setupDrawShader() {
937    if (mShader) {
938        mShader->describe(mDescription, mCaches.extensions);
939    }
940}
941
942void OpenGLRenderer::setupDrawColorFilter() {
943    if (mColorFilter) {
944        mColorFilter->describe(mDescription, mCaches.extensions);
945    }
946}
947
948void OpenGLRenderer::setupDrawBlending(SkXfermode::Mode mode, bool swapSrcDst) {
949    chooseBlending((mColorSet && mColorA < 1.0f) || (mShader && mShader->blend()), mode,
950            mDescription, swapSrcDst);
951}
952
953void OpenGLRenderer::setupDrawBlending(bool blend, SkXfermode::Mode mode, bool swapSrcDst) {
954    chooseBlending(blend || (mColorSet && mColorA < 1.0f) || (mShader && mShader->blend()), mode,
955            mDescription, swapSrcDst);
956}
957
958void OpenGLRenderer::setupDrawProgram() {
959    useProgram(mCaches.programCache.get(mDescription));
960}
961
962void OpenGLRenderer::setupDrawDirtyRegionsDisabled() {
963    mTrackDirtyRegions = false;
964}
965
966void OpenGLRenderer::setupDrawModelViewTranslate(float left, float top, float right, float bottom,
967        bool ignoreTransform) {
968    mModelView.loadTranslate(left, top, 0.0f);
969    if (!ignoreTransform) {
970        mCaches.currentProgram->set(mOrthoMatrix, mModelView, *mSnapshot->transform);
971        if (mTrackDirtyRegions) dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
972    } else {
973        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mIdentity);
974        if (mTrackDirtyRegions) dirtyLayer(left, top, right, bottom);
975    }
976}
977
978void OpenGLRenderer::setupDrawModelViewIdentity() {
979    mCaches.currentProgram->set(mOrthoMatrix, mIdentity, *mSnapshot->transform);
980}
981
982void OpenGLRenderer::setupDrawModelView(float left, float top, float right, float bottom,
983        bool ignoreTransform, bool ignoreModelView) {
984    if (!ignoreModelView) {
985        mModelView.loadTranslate(left, top, 0.0f);
986        mModelView.scale(right - left, bottom - top, 1.0f);
987    } else {
988        mModelView.loadIdentity();
989    }
990    bool dirty = right - left > 0.0f && bottom - top > 0.0f;
991    if (!ignoreTransform) {
992        mCaches.currentProgram->set(mOrthoMatrix, mModelView, *mSnapshot->transform);
993        if (mTrackDirtyRegions && dirty) {
994            dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
995        }
996    } else {
997        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mIdentity);
998        if (mTrackDirtyRegions && dirty) dirtyLayer(left, top, right, bottom);
999    }
1000}
1001
1002void OpenGLRenderer::setupDrawColorUniforms() {
1003    if (mColorSet || (mShader && mSetShaderColor)) {
1004        mCaches.currentProgram->setColor(mColorR, mColorG, mColorB, mColorA);
1005    }
1006}
1007
1008void OpenGLRenderer::setupDrawPureColorUniforms() {
1009    if (mSetShaderColor) {
1010        mCaches.currentProgram->setColor(mColorR, mColorG, mColorB, mColorA);
1011    }
1012}
1013
1014void OpenGLRenderer::setupDrawShaderUniforms(bool ignoreTransform) {
1015    if (mShader) {
1016        if (ignoreTransform) {
1017            mModelView.loadInverse(*mSnapshot->transform);
1018        }
1019        mShader->setupProgram(mCaches.currentProgram, mModelView, *mSnapshot, &mTextureUnit);
1020    }
1021}
1022
1023void OpenGLRenderer::setupDrawShaderIdentityUniforms() {
1024    if (mShader) {
1025        mShader->setupProgram(mCaches.currentProgram, mIdentity, *mSnapshot, &mTextureUnit);
1026    }
1027}
1028
1029void OpenGLRenderer::setupDrawColorFilterUniforms() {
1030    if (mColorFilter) {
1031        mColorFilter->setupProgram(mCaches.currentProgram);
1032    }
1033}
1034
1035void OpenGLRenderer::setupDrawSimpleMesh() {
1036    mCaches.bindMeshBuffer();
1037    glVertexAttribPointer(mCaches.currentProgram->position, 2, GL_FLOAT, GL_FALSE,
1038            gMeshStride, 0);
1039}
1040
1041void OpenGLRenderer::setupDrawTexture(GLuint texture) {
1042    bindTexture(texture);
1043    glUniform1i(mCaches.currentProgram->getUniform("sampler"), mTextureUnit++);
1044
1045    mTexCoordsSlot = mCaches.currentProgram->getAttrib("texCoords");
1046    glEnableVertexAttribArray(mTexCoordsSlot);
1047}
1048
1049void OpenGLRenderer::setupDrawMesh(GLvoid* vertices, GLvoid* texCoords, GLuint vbo) {
1050    if (!vertices) {
1051        mCaches.bindMeshBuffer(vbo == 0 ? mCaches.meshBuffer : vbo);
1052    } else {
1053        mCaches.unbindMeshBuffer();
1054    }
1055    glVertexAttribPointer(mCaches.currentProgram->position, 2, GL_FLOAT, GL_FALSE,
1056            gMeshStride, vertices);
1057    if (mTexCoordsSlot >= 0) {
1058        glVertexAttribPointer(mTexCoordsSlot, 2, GL_FLOAT, GL_FALSE, gMeshStride, texCoords);
1059    }
1060}
1061
1062void OpenGLRenderer::finishDrawTexture() {
1063    glDisableVertexAttribArray(mTexCoordsSlot);
1064}
1065
1066///////////////////////////////////////////////////////////////////////////////
1067// Drawing
1068///////////////////////////////////////////////////////////////////////////////
1069
1070bool OpenGLRenderer::drawDisplayList(DisplayList* displayList, uint32_t width, uint32_t height,
1071        Rect& dirty, uint32_t level) {
1072    if (quickReject(0.0f, 0.0f, width, height)) {
1073        return false;
1074    }
1075
1076    // All the usual checks and setup operations (quickReject, setupDraw, etc.)
1077    // will be performed by the display list itself
1078    if (displayList) {
1079        return displayList->replay(*this, dirty, level);
1080    }
1081
1082    return false;
1083}
1084
1085void OpenGLRenderer::drawBitmap(SkBitmap* bitmap, float left, float top, SkPaint* paint) {
1086    const float right = left + bitmap->width();
1087    const float bottom = top + bitmap->height();
1088
1089    if (quickReject(left, top, right, bottom)) {
1090        return;
1091    }
1092
1093    glActiveTexture(gTextureUnits[0]);
1094    Texture* texture = mCaches.textureCache.get(bitmap);
1095    if (!texture) return;
1096    const AutoTexture autoCleanup(texture);
1097
1098    drawTextureRect(left, top, right, bottom, texture, paint);
1099}
1100
1101void OpenGLRenderer::drawBitmap(SkBitmap* bitmap, SkMatrix* matrix, SkPaint* paint) {
1102    Rect r(0.0f, 0.0f, bitmap->width(), bitmap->height());
1103    const mat4 transform(*matrix);
1104    transform.mapRect(r);
1105
1106    if (quickReject(r.left, r.top, r.right, r.bottom)) {
1107        return;
1108    }
1109
1110    glActiveTexture(gTextureUnits[0]);
1111    Texture* texture = mCaches.textureCache.get(bitmap);
1112    if (!texture) return;
1113    const AutoTexture autoCleanup(texture);
1114
1115    // This could be done in a cheaper way, all we need is pass the matrix
1116    // to the vertex shader. The save/restore is a bit overkill.
1117    save(SkCanvas::kMatrix_SaveFlag);
1118    concatMatrix(matrix);
1119    drawTextureRect(0.0f, 0.0f, bitmap->width(), bitmap->height(), texture, paint);
1120    restore();
1121}
1122
1123void OpenGLRenderer::drawBitmapMesh(SkBitmap* bitmap, int meshWidth, int meshHeight,
1124        float* vertices, int* colors, SkPaint* paint) {
1125    // TODO: Do a quickReject
1126    if (!vertices || mSnapshot->isIgnored()) {
1127        return;
1128    }
1129
1130    glActiveTexture(gTextureUnits[0]);
1131    Texture* texture = mCaches.textureCache.get(bitmap);
1132    if (!texture) return;
1133    const AutoTexture autoCleanup(texture);
1134    setTextureWrapModes(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
1135
1136    int alpha;
1137    SkXfermode::Mode mode;
1138    getAlphaAndMode(paint, &alpha, &mode);
1139
1140    const uint32_t count = meshWidth * meshHeight * 6;
1141
1142    float left = FLT_MAX;
1143    float top = FLT_MAX;
1144    float right = FLT_MIN;
1145    float bottom = FLT_MIN;
1146
1147#if RENDER_LAYERS_AS_REGIONS
1148    bool hasActiveLayer = hasLayer();
1149#else
1150    bool hasActiveLayer = false;
1151#endif
1152
1153    // TODO: Support the colors array
1154    TextureVertex mesh[count];
1155    TextureVertex* vertex = mesh;
1156    for (int32_t y = 0; y < meshHeight; y++) {
1157        for (int32_t x = 0; x < meshWidth; x++) {
1158            uint32_t i = (y * (meshWidth + 1) + x) * 2;
1159
1160            float u1 = float(x) / meshWidth;
1161            float u2 = float(x + 1) / meshWidth;
1162            float v1 = float(y) / meshHeight;
1163            float v2 = float(y + 1) / meshHeight;
1164
1165            int ax = i + (meshWidth + 1) * 2;
1166            int ay = ax + 1;
1167            int bx = i;
1168            int by = bx + 1;
1169            int cx = i + 2;
1170            int cy = cx + 1;
1171            int dx = i + (meshWidth + 1) * 2 + 2;
1172            int dy = dx + 1;
1173
1174            TextureVertex::set(vertex++, vertices[ax], vertices[ay], u1, v2);
1175            TextureVertex::set(vertex++, vertices[bx], vertices[by], u1, v1);
1176            TextureVertex::set(vertex++, vertices[cx], vertices[cy], u2, v1);
1177
1178            TextureVertex::set(vertex++, vertices[ax], vertices[ay], u1, v2);
1179            TextureVertex::set(vertex++, vertices[cx], vertices[cy], u2, v1);
1180            TextureVertex::set(vertex++, vertices[dx], vertices[dy], u2, v2);
1181
1182#if RENDER_LAYERS_AS_REGIONS
1183            if (hasActiveLayer) {
1184                // TODO: This could be optimized to avoid unnecessary ops
1185                left = fminf(left, fminf(vertices[ax], fminf(vertices[bx], vertices[cx])));
1186                top = fminf(top, fminf(vertices[ay], fminf(vertices[by], vertices[cy])));
1187                right = fmaxf(right, fmaxf(vertices[ax], fmaxf(vertices[bx], vertices[cx])));
1188                bottom = fmaxf(bottom, fmaxf(vertices[ay], fmaxf(vertices[by], vertices[cy])));
1189            }
1190#endif
1191        }
1192    }
1193
1194#if RENDER_LAYERS_AS_REGIONS
1195    if (hasActiveLayer) {
1196        dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
1197    }
1198#endif
1199
1200    drawTextureMesh(0.0f, 0.0f, 1.0f, 1.0f, texture->id, alpha / 255.0f,
1201            mode, texture->blend, &mesh[0].position[0], &mesh[0].texture[0],
1202            GL_TRIANGLES, count, false, false, 0, false, false);
1203}
1204
1205void OpenGLRenderer::drawBitmap(SkBitmap* bitmap,
1206         float srcLeft, float srcTop, float srcRight, float srcBottom,
1207         float dstLeft, float dstTop, float dstRight, float dstBottom,
1208         SkPaint* paint) {
1209    if (quickReject(dstLeft, dstTop, dstRight, dstBottom)) {
1210        return;
1211    }
1212
1213    glActiveTexture(gTextureUnits[0]);
1214    Texture* texture = mCaches.textureCache.get(bitmap);
1215    if (!texture) return;
1216    const AutoTexture autoCleanup(texture);
1217    setTextureWrapModes(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
1218
1219    const float width = texture->width;
1220    const float height = texture->height;
1221
1222    const float u1 = srcLeft / width;
1223    const float v1 = srcTop / height;
1224    const float u2 = srcRight / width;
1225    const float v2 = srcBottom / height;
1226
1227    mCaches.unbindMeshBuffer();
1228    resetDrawTextureTexCoords(u1, v1, u2, v2);
1229
1230    int alpha;
1231    SkXfermode::Mode mode;
1232    getAlphaAndMode(paint, &alpha, &mode);
1233
1234    if (mSnapshot->transform->isPureTranslate()) {
1235        const float x = (int) floorf(dstLeft + mSnapshot->transform->getTranslateX() + 0.5f);
1236        const float y = (int) floorf(dstTop + mSnapshot->transform->getTranslateY() + 0.5f);
1237
1238        drawTextureMesh(x, y, x + (dstRight - dstLeft), y + (dstBottom - dstTop),
1239                texture->id, alpha / 255.0f, mode, texture->blend,
1240                &mMeshVertices[0].position[0], &mMeshVertices[0].texture[0],
1241                GL_TRIANGLE_STRIP, gMeshCount, false, true);
1242    } else {
1243        drawTextureMesh(dstLeft, dstTop, dstRight, dstBottom, texture->id, alpha / 255.0f,
1244                mode, texture->blend, &mMeshVertices[0].position[0], &mMeshVertices[0].texture[0],
1245                GL_TRIANGLE_STRIP, gMeshCount);
1246    }
1247
1248    resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
1249}
1250
1251void OpenGLRenderer::drawPatch(SkBitmap* bitmap, const int32_t* xDivs, const int32_t* yDivs,
1252        const uint32_t* colors, uint32_t width, uint32_t height, int8_t numColors,
1253        float left, float top, float right, float bottom, SkPaint* paint) {
1254    if (quickReject(left, top, right, bottom)) {
1255        return;
1256    }
1257
1258    glActiveTexture(gTextureUnits[0]);
1259    Texture* texture = mCaches.textureCache.get(bitmap);
1260    if (!texture) return;
1261    const AutoTexture autoCleanup(texture);
1262    setTextureWrapModes(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
1263
1264    int alpha;
1265    SkXfermode::Mode mode;
1266    getAlphaAndMode(paint, &alpha, &mode);
1267
1268    const Patch* mesh = mCaches.patchCache.get(bitmap->width(), bitmap->height(),
1269            right - left, bottom - top, xDivs, yDivs, colors, width, height, numColors);
1270
1271    if (mesh && mesh->verticesCount > 0) {
1272        const bool pureTranslate = mSnapshot->transform->isPureTranslate();
1273#if RENDER_LAYERS_AS_REGIONS
1274        // Mark the current layer dirty where we are going to draw the patch
1275        if (hasLayer() && mesh->hasEmptyQuads) {
1276            const float offsetX = left + mSnapshot->transform->getTranslateX();
1277            const float offsetY = top + mSnapshot->transform->getTranslateY();
1278            const size_t count = mesh->quads.size();
1279            for (size_t i = 0; i < count; i++) {
1280                const Rect& bounds = mesh->quads.itemAt(i);
1281                if (pureTranslate) {
1282                    const float x = (int) floorf(bounds.left + offsetX + 0.5f);
1283                    const float y = (int) floorf(bounds.top + offsetY + 0.5f);
1284                    dirtyLayer(x, y, x + bounds.getWidth(), y + bounds.getHeight());
1285                } else {
1286                    dirtyLayer(left + bounds.left, top + bounds.top,
1287                            left + bounds.right, top + bounds.bottom, *mSnapshot->transform);
1288                }
1289            }
1290        }
1291#endif
1292
1293        if (pureTranslate) {
1294            const float x = (int) floorf(left + mSnapshot->transform->getTranslateX() + 0.5f);
1295            const float y = (int) floorf(top + mSnapshot->transform->getTranslateY() + 0.5f);
1296
1297            drawTextureMesh(x, y, x + right - left, y + bottom - top, texture->id, alpha / 255.0f,
1298                    mode, texture->blend, (GLvoid*) 0, (GLvoid*) gMeshTextureOffset,
1299                    GL_TRIANGLES, mesh->verticesCount, false, true, mesh->meshBuffer,
1300                    true, !mesh->hasEmptyQuads);
1301        } else {
1302            drawTextureMesh(left, top, right, bottom, texture->id, alpha / 255.0f,
1303                    mode, texture->blend, (GLvoid*) 0, (GLvoid*) gMeshTextureOffset,
1304                    GL_TRIANGLES, mesh->verticesCount, false, false, mesh->meshBuffer,
1305                    true, !mesh->hasEmptyQuads);
1306        }
1307    }
1308}
1309
1310void OpenGLRenderer::drawLines(float* points, int count, SkPaint* paint) {
1311    if (mSnapshot->isIgnored()) return;
1312
1313    const bool isAA = paint->isAntiAlias();
1314    const float strokeWidth = paint->getStrokeWidth() * 0.5f;
1315    // A stroke width of 0 has a special meaningin Skia:
1316    // it draws an unscaled 1px wide line
1317    const bool isHairLine = paint->getStrokeWidth() == 0.0f;
1318
1319    int alpha;
1320    SkXfermode::Mode mode;
1321    getAlphaAndMode(paint, &alpha, &mode);
1322
1323    int verticesCount = count >> 2;
1324    int generatedVerticesCount = 0;
1325    if (!isHairLine) {
1326        // TODO: AA needs more vertices
1327        verticesCount *= 6;
1328    } else {
1329        // TODO: AA will be different
1330        verticesCount *= 2;
1331    }
1332
1333    TextureVertex lines[verticesCount];
1334    TextureVertex* vertex = &lines[0];
1335
1336    setupDraw();
1337    setupDrawColor(paint->getColor(), alpha);
1338    setupDrawColorFilter();
1339    setupDrawShader();
1340    setupDrawBlending(mode);
1341    setupDrawProgram();
1342    setupDrawModelViewIdentity();
1343    setupDrawColorUniforms();
1344    setupDrawColorFilterUniforms();
1345    setupDrawShaderIdentityUniforms();
1346    setupDrawMesh(vertex);
1347
1348    if (!isHairLine) {
1349        // TODO: Handle the AA case
1350        for (int i = 0; i < count; i += 4) {
1351            // a = start point, b = end point
1352            vec2 a(points[i], points[i + 1]);
1353            vec2 b(points[i + 2], points[i + 3]);
1354
1355            // Bias to snap to the same pixels as Skia
1356            a += 0.375;
1357            b += 0.375;
1358
1359            // Find the normal to the line
1360            vec2 n = (b - a).copyNormalized() * strokeWidth;
1361            float x = n.x;
1362            n.x = -n.y;
1363            n.y = x;
1364
1365            // Four corners of the rectangle defining a thick line
1366            vec2 p1 = a - n;
1367            vec2 p2 = a + n;
1368            vec2 p3 = b + n;
1369            vec2 p4 = b - n;
1370
1371            const float left = fmin(p1.x, fmin(p2.x, fmin(p3.x, p4.x)));
1372            const float right = fmax(p1.x, fmax(p2.x, fmax(p3.x, p4.x)));
1373            const float top = fmin(p1.y, fmin(p2.y, fmin(p3.y, p4.y)));
1374            const float bottom = fmax(p1.y, fmax(p2.y, fmax(p3.y, p4.y)));
1375
1376            if (!quickReject(left, top, right, bottom)) {
1377                // Draw the line as 2 triangles, could be optimized
1378                // by using only 4 vertices and the correct indices
1379                // Also we should probably used non textured vertices
1380                // when line AA is disabled to save on bandwidth
1381                TextureVertex::set(vertex++, p1.x, p1.y, 0.0f, 0.0f);
1382                TextureVertex::set(vertex++, p2.x, p2.y, 0.0f, 0.0f);
1383                TextureVertex::set(vertex++, p3.x, p3.y, 0.0f, 0.0f);
1384                TextureVertex::set(vertex++, p1.x, p1.y, 0.0f, 0.0f);
1385                TextureVertex::set(vertex++, p3.x, p3.y, 0.0f, 0.0f);
1386                TextureVertex::set(vertex++, p4.x, p4.y, 0.0f, 0.0f);
1387
1388                generatedVerticesCount += 6;
1389
1390                dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
1391            }
1392        }
1393
1394        if (generatedVerticesCount > 0) {
1395            // GL_LINE does not give the result we want to match Skia
1396            glDrawArrays(GL_TRIANGLES, 0, generatedVerticesCount);
1397        }
1398    } else {
1399        // TODO: Handle the AA case
1400        for (int i = 0; i < count; i += 4) {
1401            const float left = fmin(points[i], points[i + 1]);
1402            const float right = fmax(points[i], points[i + 1]);
1403            const float top = fmin(points[i + 2], points[i + 3]);
1404            const float bottom = fmax(points[i + 2], points[i + 3]);
1405
1406            if (!quickReject(left, top, right, bottom)) {
1407                TextureVertex::set(vertex++, points[i], points[i + 1], 0.0f, 0.0f);
1408                TextureVertex::set(vertex++, points[i + 2], points[i + 3], 0.0f, 0.0f);
1409
1410                generatedVerticesCount += 2;
1411
1412                dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
1413            }
1414        }
1415
1416        if (generatedVerticesCount > 0) {
1417            glLineWidth(1.0f);
1418            glDrawArrays(GL_LINES, 0, generatedVerticesCount);
1419        }
1420    }
1421}
1422
1423void OpenGLRenderer::drawColor(int color, SkXfermode::Mode mode) {
1424    // No need to check against the clip, we fill the clip region
1425    if (mSnapshot->isIgnored()) return;
1426
1427    Rect& clip(*mSnapshot->clipRect);
1428    clip.snapToPixelBoundaries();
1429
1430    drawColorRect(clip.left, clip.top, clip.right, clip.bottom, color, mode, true);
1431}
1432
1433void OpenGLRenderer::drawShape(float left, float top, const PathTexture* texture, SkPaint* paint) {
1434    if (!texture) return;
1435    const AutoTexture autoCleanup(texture);
1436
1437    const float x = left + texture->left - texture->offset;
1438    const float y = top + texture->top - texture->offset;
1439
1440    drawPathTexture(texture, x, y, paint);
1441}
1442
1443void OpenGLRenderer::drawRoundRect(float left, float top, float right, float bottom,
1444        float rx, float ry, SkPaint* paint) {
1445    if (mSnapshot->isIgnored()) return;
1446
1447    glActiveTexture(gTextureUnits[0]);
1448    const PathTexture* texture = mCaches.roundRectShapeCache.getRoundRect(
1449            right - left, bottom - top, rx, ry, paint);
1450    drawShape(left, top, texture, paint);
1451}
1452
1453void OpenGLRenderer::drawCircle(float x, float y, float radius, SkPaint* paint) {
1454    if (mSnapshot->isIgnored()) return;
1455
1456    glActiveTexture(gTextureUnits[0]);
1457    const PathTexture* texture = mCaches.circleShapeCache.getCircle(radius, paint);
1458    drawShape(x - radius, y - radius, texture, paint);
1459}
1460
1461void OpenGLRenderer::drawOval(float left, float top, float right, float bottom, SkPaint* paint) {
1462    if (mSnapshot->isIgnored()) return;
1463
1464    glActiveTexture(gTextureUnits[0]);
1465    const PathTexture* texture = mCaches.ovalShapeCache.getOval(right - left, bottom - top, paint);
1466    drawShape(left, top, texture, paint);
1467}
1468
1469void OpenGLRenderer::drawArc(float left, float top, float right, float bottom,
1470        float startAngle, float sweepAngle, bool useCenter, SkPaint* paint) {
1471    if (mSnapshot->isIgnored()) return;
1472
1473    if (fabs(sweepAngle) >= 360.0f) {
1474        drawOval(left, top, right, bottom, paint);
1475        return;
1476    }
1477
1478    glActiveTexture(gTextureUnits[0]);
1479    const PathTexture* texture = mCaches.arcShapeCache.getArc(right - left, bottom - top,
1480            startAngle, sweepAngle, useCenter, paint);
1481    drawShape(left, top, texture, paint);
1482}
1483
1484void OpenGLRenderer::drawRectAsShape(float left, float top, float right, float bottom,
1485        SkPaint* paint) {
1486    if (mSnapshot->isIgnored()) return;
1487
1488    glActiveTexture(gTextureUnits[0]);
1489    const PathTexture* texture = mCaches.rectShapeCache.getRect(right - left, bottom - top, paint);
1490    drawShape(left, top, texture, paint);
1491}
1492
1493void OpenGLRenderer::drawRect(float left, float top, float right, float bottom, SkPaint* p) {
1494    if (p->getStyle() != SkPaint::kFill_Style) {
1495        drawRectAsShape(left, top, right, bottom, p);
1496        return;
1497    }
1498
1499    if (quickReject(left, top, right, bottom)) {
1500        return;
1501    }
1502
1503    SkXfermode::Mode mode;
1504    if (!mCaches.extensions.hasFramebufferFetch()) {
1505        const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode);
1506        if (!isMode) {
1507            // Assume SRC_OVER
1508            mode = SkXfermode::kSrcOver_Mode;
1509        }
1510    } else {
1511        mode = getXfermode(p->getXfermode());
1512    }
1513
1514    int color = p->getColor();
1515    drawColorRect(left, top, right, bottom, color, mode);
1516}
1517
1518void OpenGLRenderer::drawText(const char* text, int bytesCount, int count,
1519        float x, float y, SkPaint* paint) {
1520    if (text == NULL || count == 0) {
1521        return;
1522    }
1523    if (mSnapshot->isIgnored()) return;
1524
1525    paint->setAntiAlias(true);
1526
1527    float length = -1.0f;
1528    switch (paint->getTextAlign()) {
1529        case SkPaint::kCenter_Align:
1530            length = paint->measureText(text, bytesCount);
1531            x -= length / 2.0f;
1532            break;
1533        case SkPaint::kRight_Align:
1534            length = paint->measureText(text, bytesCount);
1535            x -= length;
1536            break;
1537        default:
1538            break;
1539    }
1540
1541    const float oldX = x;
1542    const float oldY = y;
1543    const bool pureTranslate = mSnapshot->transform->isPureTranslate();
1544    if (pureTranslate) {
1545        x = (int) floorf(x + mSnapshot->transform->getTranslateX() + 0.5f);
1546        y = (int) floorf(y + mSnapshot->transform->getTranslateY() + 0.5f);
1547    }
1548
1549    FontRenderer& fontRenderer = mCaches.fontRenderer.getFontRenderer(paint);
1550    fontRenderer.setFont(paint, SkTypeface::UniqueID(paint->getTypeface()),
1551            paint->getTextSize());
1552
1553    int alpha;
1554    SkXfermode::Mode mode;
1555    getAlphaAndMode(paint, &alpha, &mode);
1556
1557    if (mHasShadow) {
1558        mCaches.dropShadowCache.setFontRenderer(fontRenderer);
1559        const ShadowTexture* shadow = mCaches.dropShadowCache.get(paint, text, bytesCount,
1560                count, mShadowRadius);
1561        const AutoTexture autoCleanup(shadow);
1562
1563        const float sx = x - shadow->left + mShadowDx;
1564        const float sy = y - shadow->top + mShadowDy;
1565
1566        const int shadowAlpha = ((mShadowColor >> 24) & 0xFF);
1567
1568        glActiveTexture(gTextureUnits[0]);
1569        setupDraw();
1570        setupDrawWithTexture(true);
1571        setupDrawAlpha8Color(mShadowColor, shadowAlpha < 255 ? shadowAlpha : alpha);
1572        setupDrawBlending(true, mode);
1573        setupDrawProgram();
1574        setupDrawModelView(sx, sy, sx + shadow->width, sy + shadow->height, pureTranslate);
1575        setupDrawTexture(shadow->id);
1576        setupDrawPureColorUniforms();
1577        setupDrawMesh(NULL, (GLvoid*) gMeshTextureOffset);
1578
1579        glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
1580        finishDrawTexture();
1581    }
1582
1583    if (paint->getAlpha() == 0 && paint->getXfermode() == NULL) {
1584        return;
1585    }
1586
1587    // Pick the appropriate texture filtering
1588    bool linearFilter = mSnapshot->transform->changesBounds();
1589    if (pureTranslate && !linearFilter) {
1590        linearFilter = fabs(y - (int) y) > 0.0f || fabs(x - (int) x) > 0.0f;
1591    }
1592
1593    glActiveTexture(gTextureUnits[0]);
1594    setupDraw();
1595    setupDrawDirtyRegionsDisabled();
1596    setupDrawWithTexture(true);
1597    setupDrawAlpha8Color(paint->getColor(), alpha);
1598    setupDrawColorFilter();
1599    setupDrawShader();
1600    setupDrawBlending(true, mode);
1601    setupDrawProgram();
1602    setupDrawModelView(x, y, x, y, pureTranslate, true);
1603    setupDrawTexture(fontRenderer.getTexture(linearFilter));
1604    setupDrawPureColorUniforms();
1605    setupDrawColorFilterUniforms();
1606    setupDrawShaderUniforms(pureTranslate);
1607
1608    const Rect* clip = pureTranslate ? mSnapshot->clipRect : &mSnapshot->getLocalClip();
1609    Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
1610
1611#if RENDER_LAYERS_AS_REGIONS
1612    bool hasActiveLayer = hasLayer();
1613#else
1614    bool hasActiveLayer = false;
1615#endif
1616    mCaches.unbindMeshBuffer();
1617
1618    // Tell font renderer the locations of position and texture coord
1619    // attributes so it can bind its data properly
1620    int positionSlot = mCaches.currentProgram->position;
1621    fontRenderer.setAttributeBindingSlots(positionSlot, mTexCoordsSlot);
1622    if (fontRenderer.renderText(paint, clip, text, 0, bytesCount, count, x, y,
1623            hasActiveLayer ? &bounds : NULL)) {
1624#if RENDER_LAYERS_AS_REGIONS
1625        if (hasActiveLayer) {
1626            if (!pureTranslate) {
1627                mSnapshot->transform->mapRect(bounds);
1628            }
1629            dirtyLayerUnchecked(bounds, getRegion());
1630        }
1631#endif
1632    }
1633
1634    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
1635    glDisableVertexAttribArray(mCaches.currentProgram->getAttrib("texCoords"));
1636
1637    drawTextDecorations(text, bytesCount, length, oldX, oldY, paint);
1638}
1639
1640void OpenGLRenderer::drawPath(SkPath* path, SkPaint* paint) {
1641    if (mSnapshot->isIgnored()) return;
1642
1643    glActiveTexture(gTextureUnits[0]);
1644
1645    const PathTexture* texture = mCaches.pathCache.get(path, paint);
1646    if (!texture) return;
1647    const AutoTexture autoCleanup(texture);
1648
1649    const float x = texture->left - texture->offset;
1650    const float y = texture->top - texture->offset;
1651
1652    drawPathTexture(texture, x, y, paint);
1653}
1654
1655void OpenGLRenderer::drawLayer(Layer* layer, float x, float y, SkPaint* paint) {
1656    if (!layer || quickReject(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight())) {
1657        return;
1658    }
1659
1660    glActiveTexture(gTextureUnits[0]);
1661
1662    int alpha;
1663    SkXfermode::Mode mode;
1664    getAlphaAndMode(paint, &alpha, &mode);
1665
1666    layer->alpha = alpha;
1667    layer->mode = mode;
1668
1669#if RENDER_LAYERS_AS_REGIONS
1670    if (!layer->region.isEmpty()) {
1671#if RENDER_LAYERS_RECT_AS_RECT
1672        if (layer->region.isRect()) {
1673            const Rect r(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight());
1674            composeLayerRect(layer, r);
1675        } else if (layer->mesh) {
1676#else
1677        if (layer->mesh) {
1678#endif
1679            const float a = alpha / 255.0f;
1680            const Rect& rect = layer->layer;
1681
1682            setupDraw();
1683            setupDrawWithTexture();
1684            setupDrawColor(a, a, a, a);
1685            setupDrawColorFilter();
1686            setupDrawBlending(layer->blend || layer->alpha < 255, layer->mode, false);
1687            setupDrawProgram();
1688            setupDrawPureColorUniforms();
1689            setupDrawColorFilterUniforms();
1690            setupDrawTexture(layer->texture);
1691            // TODO: The current layer, if any, will be dirtied with the bounding box
1692            //       of the layer we are drawing. Since the layer we are drawing has
1693            //       a mesh, we know the dirty region, we should use it instead
1694            setupDrawModelViewTranslate(rect.left, rect.top, rect.right, rect.bottom);
1695            setupDrawMesh(&layer->mesh[0].position[0], &layer->mesh[0].texture[0]);
1696
1697            glDrawElements(GL_TRIANGLES, layer->meshElementCount,
1698                    GL_UNSIGNED_SHORT, layer->meshIndices);
1699
1700            finishDrawTexture();
1701
1702#if DEBUG_LAYERS_AS_REGIONS
1703            drawRegionRects(layer->region);
1704#endif
1705        }
1706    }
1707#else
1708    const Rect r(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight());
1709    composeLayerRect(layer, r);
1710#endif
1711}
1712
1713///////////////////////////////////////////////////////////////////////////////
1714// Shaders
1715///////////////////////////////////////////////////////////////////////////////
1716
1717void OpenGLRenderer::resetShader() {
1718    mShader = NULL;
1719}
1720
1721void OpenGLRenderer::setupShader(SkiaShader* shader) {
1722    mShader = shader;
1723    if (mShader) {
1724        mShader->set(&mCaches.textureCache, &mCaches.gradientCache);
1725    }
1726}
1727
1728///////////////////////////////////////////////////////////////////////////////
1729// Color filters
1730///////////////////////////////////////////////////////////////////////////////
1731
1732void OpenGLRenderer::resetColorFilter() {
1733    mColorFilter = NULL;
1734}
1735
1736void OpenGLRenderer::setupColorFilter(SkiaColorFilter* filter) {
1737    mColorFilter = filter;
1738}
1739
1740///////////////////////////////////////////////////////////////////////////////
1741// Drop shadow
1742///////////////////////////////////////////////////////////////////////////////
1743
1744void OpenGLRenderer::resetShadow() {
1745    mHasShadow = false;
1746}
1747
1748void OpenGLRenderer::setupShadow(float radius, float dx, float dy, int color) {
1749    mHasShadow = true;
1750    mShadowRadius = radius;
1751    mShadowDx = dx;
1752    mShadowDy = dy;
1753    mShadowColor = color;
1754}
1755
1756///////////////////////////////////////////////////////////////////////////////
1757// Drawing implementation
1758///////////////////////////////////////////////////////////////////////////////
1759
1760void OpenGLRenderer::drawPathTexture(const PathTexture* texture,
1761        float x, float y, SkPaint* paint) {
1762    if (quickReject(x, y, x + texture->width, y + texture->height)) {
1763        return;
1764    }
1765
1766    int alpha;
1767    SkXfermode::Mode mode;
1768    getAlphaAndMode(paint, &alpha, &mode);
1769
1770    setupDraw();
1771    setupDrawWithTexture(true);
1772    setupDrawAlpha8Color(paint->getColor(), alpha);
1773    setupDrawColorFilter();
1774    setupDrawShader();
1775    setupDrawBlending(true, mode);
1776    setupDrawProgram();
1777    setupDrawModelView(x, y, x + texture->width, y + texture->height);
1778    setupDrawTexture(texture->id);
1779    setupDrawPureColorUniforms();
1780    setupDrawColorFilterUniforms();
1781    setupDrawShaderUniforms();
1782    setupDrawMesh(NULL, (GLvoid*) gMeshTextureOffset);
1783
1784    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
1785
1786    finishDrawTexture();
1787}
1788
1789// Same values used by Skia
1790#define kStdStrikeThru_Offset   (-6.0f / 21.0f)
1791#define kStdUnderline_Offset    (1.0f / 9.0f)
1792#define kStdUnderline_Thickness (1.0f / 18.0f)
1793
1794void OpenGLRenderer::drawTextDecorations(const char* text, int bytesCount, float length,
1795        float x, float y, SkPaint* paint) {
1796    // Handle underline and strike-through
1797    uint32_t flags = paint->getFlags();
1798    if (flags & (SkPaint::kUnderlineText_Flag | SkPaint::kStrikeThruText_Flag)) {
1799        float underlineWidth = length;
1800        // If length is > 0.0f, we already measured the text for the text alignment
1801        if (length <= 0.0f) {
1802            underlineWidth = paint->measureText(text, bytesCount);
1803        }
1804
1805        float offsetX = 0;
1806        switch (paint->getTextAlign()) {
1807            case SkPaint::kCenter_Align:
1808                offsetX = underlineWidth * 0.5f;
1809                break;
1810            case SkPaint::kRight_Align:
1811                offsetX = underlineWidth;
1812                break;
1813            default:
1814                break;
1815        }
1816
1817        if (underlineWidth > 0.0f) {
1818            const float textSize = paint->getTextSize();
1819            // TODO: Support stroke width < 1.0f when we have AA lines
1820            const float strokeWidth = fmax(textSize * kStdUnderline_Thickness, 1.0f);
1821
1822            const float left = x - offsetX;
1823            float top = 0.0f;
1824
1825            int linesCount = 0;
1826            if (flags & SkPaint::kUnderlineText_Flag) linesCount++;
1827            if (flags & SkPaint::kStrikeThruText_Flag) linesCount++;
1828
1829            const int pointsCount = 4 * linesCount;
1830            float points[pointsCount];
1831            int currentPoint = 0;
1832
1833            if (flags & SkPaint::kUnderlineText_Flag) {
1834                top = y + textSize * kStdUnderline_Offset;
1835                points[currentPoint++] = left;
1836                points[currentPoint++] = top;
1837                points[currentPoint++] = left + underlineWidth;
1838                points[currentPoint++] = top;
1839            }
1840
1841            if (flags & SkPaint::kStrikeThruText_Flag) {
1842                top = y + textSize * kStdStrikeThru_Offset;
1843                points[currentPoint++] = left;
1844                points[currentPoint++] = top;
1845                points[currentPoint++] = left + underlineWidth;
1846                points[currentPoint++] = top;
1847            }
1848
1849            SkPaint linesPaint(*paint);
1850            linesPaint.setStrokeWidth(strokeWidth);
1851
1852            drawLines(&points[0], pointsCount, &linesPaint);
1853        }
1854    }
1855}
1856
1857void OpenGLRenderer::drawColorRect(float left, float top, float right, float bottom,
1858        int color, SkXfermode::Mode mode, bool ignoreTransform) {
1859    // If a shader is set, preserve only the alpha
1860    if (mShader) {
1861        color |= 0x00ffffff;
1862    }
1863
1864    setupDraw();
1865    setupDrawColor(color);
1866    setupDrawShader();
1867    setupDrawColorFilter();
1868    setupDrawBlending(mode);
1869    setupDrawProgram();
1870    setupDrawModelView(left, top, right, bottom, ignoreTransform);
1871    setupDrawColorUniforms();
1872    setupDrawShaderUniforms(ignoreTransform);
1873    setupDrawColorFilterUniforms();
1874    setupDrawSimpleMesh();
1875
1876    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
1877}
1878
1879void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom,
1880        Texture* texture, SkPaint* paint) {
1881    int alpha;
1882    SkXfermode::Mode mode;
1883    getAlphaAndMode(paint, &alpha, &mode);
1884
1885    setTextureWrapModes(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
1886
1887    if (mSnapshot->transform->isPureTranslate()) {
1888        const float x = (int) floorf(left + mSnapshot->transform->getTranslateX() + 0.5f);
1889        const float y = (int) floorf(top + mSnapshot->transform->getTranslateY() + 0.5f);
1890
1891        drawTextureMesh(x, y, x + texture->width, y + texture->height, texture->id,
1892                alpha / 255.0f, mode, texture->blend, (GLvoid*) NULL,
1893                (GLvoid*) gMeshTextureOffset, GL_TRIANGLE_STRIP, gMeshCount, false, true);
1894    } else {
1895        drawTextureMesh(left, top, right, bottom, texture->id, alpha / 255.0f, mode,
1896                texture->blend, (GLvoid*) NULL, (GLvoid*) gMeshTextureOffset,
1897                GL_TRIANGLE_STRIP, gMeshCount);
1898    }
1899}
1900
1901void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom,
1902        GLuint texture, float alpha, SkXfermode::Mode mode, bool blend) {
1903    drawTextureMesh(left, top, right, bottom, texture, alpha, mode, blend,
1904            (GLvoid*) NULL, (GLvoid*) gMeshTextureOffset, GL_TRIANGLE_STRIP, gMeshCount);
1905}
1906
1907void OpenGLRenderer::drawTextureMesh(float left, float top, float right, float bottom,
1908        GLuint texture, float alpha, SkXfermode::Mode mode, bool blend,
1909        GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
1910        bool swapSrcDst, bool ignoreTransform, GLuint vbo, bool ignoreScale, bool dirty) {
1911
1912    setupDraw();
1913    setupDrawWithTexture();
1914    setupDrawColor(alpha, alpha, alpha, alpha);
1915    setupDrawColorFilter();
1916    setupDrawBlending(blend, mode, swapSrcDst);
1917    setupDrawProgram();
1918    if (!dirty) {
1919        setupDrawDirtyRegionsDisabled();
1920    }
1921    if (!ignoreScale) {
1922        setupDrawModelView(left, top, right, bottom, ignoreTransform);
1923    } else {
1924        setupDrawModelViewTranslate(left, top, right, bottom, ignoreTransform);
1925    }
1926    setupDrawPureColorUniforms();
1927    setupDrawColorFilterUniforms();
1928    setupDrawTexture(texture);
1929    setupDrawMesh(vertices, texCoords, vbo);
1930
1931    glDrawArrays(drawMode, 0, elementsCount);
1932
1933    finishDrawTexture();
1934}
1935
1936void OpenGLRenderer::chooseBlending(bool blend, SkXfermode::Mode mode,
1937        ProgramDescription& description, bool swapSrcDst) {
1938    blend = blend || mode != SkXfermode::kSrcOver_Mode;
1939    if (blend) {
1940        if (mode < SkXfermode::kPlus_Mode) {
1941            if (!mCaches.blend) {
1942                glEnable(GL_BLEND);
1943            }
1944
1945            GLenum sourceMode = swapSrcDst ? gBlendsSwap[mode].src : gBlends[mode].src;
1946            GLenum destMode = swapSrcDst ? gBlendsSwap[mode].dst : gBlends[mode].dst;
1947
1948            if (sourceMode != mCaches.lastSrcMode || destMode != mCaches.lastDstMode) {
1949                glBlendFunc(sourceMode, destMode);
1950                mCaches.lastSrcMode = sourceMode;
1951                mCaches.lastDstMode = destMode;
1952            }
1953        } else {
1954            // These blend modes are not supported by OpenGL directly and have
1955            // to be implemented using shaders. Since the shader will perform
1956            // the blending, turn blending off here
1957            if (mCaches.extensions.hasFramebufferFetch()) {
1958                description.framebufferMode = mode;
1959                description.swapSrcDst = swapSrcDst;
1960            }
1961
1962            if (mCaches.blend) {
1963                glDisable(GL_BLEND);
1964            }
1965            blend = false;
1966        }
1967    } else if (mCaches.blend) {
1968        glDisable(GL_BLEND);
1969    }
1970    mCaches.blend = blend;
1971}
1972
1973bool OpenGLRenderer::useProgram(Program* program) {
1974    if (!program->isInUse()) {
1975        if (mCaches.currentProgram != NULL) mCaches.currentProgram->remove();
1976        program->use();
1977        mCaches.currentProgram = program;
1978        return false;
1979    }
1980    return true;
1981}
1982
1983void OpenGLRenderer::resetDrawTextureTexCoords(float u1, float v1, float u2, float v2) {
1984    TextureVertex* v = &mMeshVertices[0];
1985    TextureVertex::setUV(v++, u1, v1);
1986    TextureVertex::setUV(v++, u2, v1);
1987    TextureVertex::setUV(v++, u1, v2);
1988    TextureVertex::setUV(v++, u2, v2);
1989}
1990
1991void OpenGLRenderer::getAlphaAndMode(SkPaint* paint, int* alpha, SkXfermode::Mode* mode) {
1992    if (paint) {
1993        if (!mCaches.extensions.hasFramebufferFetch()) {
1994            const bool isMode = SkXfermode::IsMode(paint->getXfermode(), mode);
1995            if (!isMode) {
1996                // Assume SRC_OVER
1997                *mode = SkXfermode::kSrcOver_Mode;
1998            }
1999        } else {
2000            *mode = getXfermode(paint->getXfermode());
2001        }
2002
2003        // Skia draws using the color's alpha channel if < 255
2004        // Otherwise, it uses the paint's alpha
2005        int color = paint->getColor();
2006        *alpha = (color >> 24) & 0xFF;
2007        if (*alpha == 255) {
2008            *alpha = paint->getAlpha();
2009        }
2010    } else {
2011        *mode = SkXfermode::kSrcOver_Mode;
2012        *alpha = 255;
2013    }
2014}
2015
2016SkXfermode::Mode OpenGLRenderer::getXfermode(SkXfermode* mode) {
2017    // In the future we should look at unifying the Porter-Duff modes and
2018    // SkXferModes so that we can use SkXfermode::IsMode(xfer, &mode).
2019    if (mode == NULL) {
2020        return SkXfermode::kSrcOver_Mode;
2021    }
2022    return mode->fMode;
2023}
2024
2025void OpenGLRenderer::setTextureWrapModes(Texture* texture, GLenum wrapS, GLenum wrapT) {
2026    bool bound = false;
2027    if (wrapS != texture->wrapS) {
2028        glBindTexture(GL_TEXTURE_2D, texture->id);
2029        bound = true;
2030        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrapS);
2031        texture->wrapS = wrapS;
2032    }
2033    if (wrapT != texture->wrapT) {
2034        if (!bound) {
2035            glBindTexture(GL_TEXTURE_2D, texture->id);
2036        }
2037        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrapT);
2038        texture->wrapT = wrapT;
2039    }
2040}
2041
2042}; // namespace uirenderer
2043}; // namespace android
2044