OpenGLRenderer.cpp revision 84962f2fe6ce779c583cc54b11a9de2b6a568117 
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) {
214    interrupt();
215    if (mDirtyClip) {
216        setScissorFromClip();
217    }
218
219#if RENDER_LAYERS_AS_REGIONS
220    // Since we don't know what the functor will draw, let's dirty
221    // tne entire clip region
222    if (hasLayer()) {
223        Rect clip(*mSnapshot->clipRect);
224        clip.snapToPixelBoundaries();
225        dirtyLayerUnchecked(clip, getRegion());
226    }
227#endif
228
229    status_t result = (*functor)();
230    resume();
231    return (result == 0) ? false : true;
232}
233
234///////////////////////////////////////////////////////////////////////////////
235// State management
236///////////////////////////////////////////////////////////////////////////////
237
238int OpenGLRenderer::getSaveCount() const {
239    return mSaveCount;
240}
241
242int OpenGLRenderer::save(int flags) {
243    return saveSnapshot(flags);
244}
245
246void OpenGLRenderer::restore() {
247    if (mSaveCount > 1) {
248        restoreSnapshot();
249    }
250}
251
252void OpenGLRenderer::restoreToCount(int saveCount) {
253    if (saveCount < 1) saveCount = 1;
254
255    while (mSaveCount > saveCount) {
256        restoreSnapshot();
257    }
258}
259
260int OpenGLRenderer::saveSnapshot(int flags) {
261    mSnapshot = new Snapshot(mSnapshot, flags);
262    return mSaveCount++;
263}
264
265bool OpenGLRenderer::restoreSnapshot() {
266    bool restoreClip = mSnapshot->flags & Snapshot::kFlagClipSet;
267    bool restoreLayer = mSnapshot->flags & Snapshot::kFlagIsLayer;
268    bool restoreOrtho = mSnapshot->flags & Snapshot::kFlagDirtyOrtho;
269
270    sp<Snapshot> current = mSnapshot;
271    sp<Snapshot> previous = mSnapshot->previous;
272
273    if (restoreOrtho) {
274        Rect& r = previous->viewport;
275        glViewport(r.left, r.top, r.right, r.bottom);
276        mOrthoMatrix.load(current->orthoMatrix);
277    }
278
279    mSaveCount--;
280    mSnapshot = previous;
281
282    if (restoreClip) {
283        dirtyClip();
284    }
285
286    if (restoreLayer) {
287        composeLayer(current, previous);
288    }
289
290    return restoreClip;
291}
292
293///////////////////////////////////////////////////////////////////////////////
294// Layers
295///////////////////////////////////////////////////////////////////////////////
296
297int OpenGLRenderer::saveLayer(float left, float top, float right, float bottom,
298        SkPaint* p, int flags) {
299    const GLuint previousFbo = mSnapshot->fbo;
300    const int count = saveSnapshot(flags);
301
302    if (!mSnapshot->isIgnored()) {
303        int alpha = 255;
304        SkXfermode::Mode mode;
305
306        if (p) {
307            alpha = p->getAlpha();
308            if (!mCaches.extensions.hasFramebufferFetch()) {
309                const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode);
310                if (!isMode) {
311                    // Assume SRC_OVER
312                    mode = SkXfermode::kSrcOver_Mode;
313                }
314            } else {
315                mode = getXfermode(p->getXfermode());
316            }
317        } else {
318            mode = SkXfermode::kSrcOver_Mode;
319        }
320
321        createLayer(mSnapshot, left, top, right, bottom, alpha, mode, flags, previousFbo);
322    }
323
324    return count;
325}
326
327int OpenGLRenderer::saveLayerAlpha(float left, float top, float right, float bottom,
328        int alpha, int flags) {
329    if (alpha >= 255 - ALPHA_THRESHOLD) {
330        return saveLayer(left, top, right, bottom, NULL, flags);
331    } else {
332        SkPaint paint;
333        paint.setAlpha(alpha);
334        return saveLayer(left, top, right, bottom, &paint, flags);
335    }
336}
337
338/**
339 * Layers are viewed by Skia are slightly different than layers in image editing
340 * programs (for instance.) When a layer is created, previously created layers
341 * and the frame buffer still receive every drawing command. For instance, if a
342 * layer is created and a shape intersecting the bounds of the layers and the
343 * framebuffer is draw, the shape will be drawn on both (unless the layer was
344 * created with the SkCanvas::kClipToLayer_SaveFlag flag.)
345 *
346 * A way to implement layers is to create an FBO for each layer, backed by an RGBA
347 * texture. Unfortunately, this is inefficient as it requires every primitive to
348 * be drawn n + 1 times, where n is the number of active layers. In practice this
349 * means, for every primitive:
350 *   - Switch active frame buffer
351 *   - Change viewport, clip and projection matrix
352 *   - Issue the drawing
353 *
354 * Switching rendering target n + 1 times per drawn primitive is extremely costly.
355 * To avoid this, layers are implemented in a different way here, at least in the
356 * general case. FBOs are used, as an optimization, when the "clip to layer" flag
357 * is set. When this flag is set we can redirect all drawing operations into a
358 * single FBO.
359 *
360 * This implementation relies on the frame buffer being at least RGBA 8888. When
361 * a layer is created, only a texture is created, not an FBO. The content of the
362 * frame buffer contained within the layer's bounds is copied into this texture
363 * using glCopyTexImage2D(). The layer's region is then cleared(1) in the frame
364 * buffer and drawing continues as normal. This technique therefore treats the
365 * frame buffer as a scratch buffer for the layers.
366 *
367 * To compose the layers back onto the frame buffer, each layer texture
368 * (containing the original frame buffer data) is drawn as a simple quad over
369 * the frame buffer. The trick is that the quad is set as the composition
370 * destination in the blending equation, and the frame buffer becomes the source
371 * of the composition.
372 *
373 * Drawing layers with an alpha value requires an extra step before composition.
374 * An empty quad is drawn over the layer's region in the frame buffer. This quad
375 * is drawn with the rgba color (0,0,0,alpha). The alpha value offered by the
376 * quad is used to multiply the colors in the frame buffer. This is achieved by
377 * changing the GL blend functions for the GL_FUNC_ADD blend equation to
378 * GL_ZERO, GL_SRC_ALPHA.
379 *
380 * Because glCopyTexImage2D() can be slow, an alternative implementation might
381 * be use to draw a single clipped layer. The implementation described above
382 * is correct in every case.
383 *
384 * (1) The frame buffer is actually not cleared right away. To allow the GPU
385 *     to potentially optimize series of calls to glCopyTexImage2D, the frame
386 *     buffer is left untouched until the first drawing operation. Only when
387 *     something actually gets drawn are the layers regions cleared.
388 */
389bool OpenGLRenderer::createLayer(sp<Snapshot> snapshot, float left, float top,
390        float right, float bottom, int alpha, SkXfermode::Mode mode,
391        int flags, GLuint previousFbo) {
392    LAYER_LOGD("Requesting layer %.2fx%.2f", right - left, bottom - top);
393    LAYER_LOGD("Layer cache size = %d", mCaches.layerCache.getSize());
394
395    const bool fboLayer = flags & SkCanvas::kClipToLayer_SaveFlag;
396
397    // Window coordinates of the layer
398    Rect bounds(left, top, right, bottom);
399    if (fboLayer) {
400        // Clear the previous layer regions before we change the viewport
401        clearLayerRegions();
402    } else {
403        mSnapshot->transform->mapRect(bounds);
404
405        // Layers only make sense if they are in the framebuffer's bounds
406        bounds.intersect(*snapshot->clipRect);
407
408        // We cannot work with sub-pixels in this case
409        bounds.snapToPixelBoundaries();
410
411        // When the layer is not an FBO, we may use glCopyTexImage so we
412        // need to make sure the layer does not extend outside the bounds
413        // of the framebuffer
414        bounds.intersect(snapshot->previous->viewport);
415    }
416
417    if (bounds.isEmpty() || bounds.getWidth() > mCaches.maxTextureSize ||
418            bounds.getHeight() > mCaches.maxTextureSize) {
419        snapshot->empty = fboLayer;
420    } else {
421        snapshot->invisible = snapshot->invisible || (alpha <= ALPHA_THRESHOLD && fboLayer);
422    }
423
424    // Bail out if we won't draw in this snapshot
425    if (snapshot->invisible || snapshot->empty) {
426        return false;
427    }
428
429    glActiveTexture(gTextureUnits[0]);
430    Layer* layer = mCaches.layerCache.get(bounds.getWidth(), bounds.getHeight());
431    if (!layer) {
432        return false;
433    }
434
435    layer->mode = mode;
436    layer->alpha = alpha;
437    layer->layer.set(bounds);
438    layer->texCoords.set(0.0f, bounds.getHeight() / float(layer->height),
439            bounds.getWidth() / float(layer->width), 0.0f);
440    layer->colorFilter = mColorFilter;
441
442    // Save the layer in the snapshot
443    snapshot->flags |= Snapshot::kFlagIsLayer;
444    snapshot->layer = layer;
445
446    if (fboLayer) {
447        return createFboLayer(layer, bounds, snapshot, previousFbo);
448    } else {
449        // Copy the framebuffer into the layer
450        glBindTexture(GL_TEXTURE_2D, layer->texture);
451        if (!bounds.isEmpty()) {
452            if (layer->empty) {
453                glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, bounds.left,
454                        snapshot->height - bounds.bottom, layer->width, layer->height, 0);
455                layer->empty = false;
456            } else {
457                glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, bounds.left,
458                        snapshot->height - bounds.bottom, bounds.getWidth(), bounds.getHeight());
459            }
460            // Enqueue the buffer coordinates to clear the corresponding region later
461            mLayers.push(new Rect(bounds));
462        }
463    }
464
465    return true;
466}
467
468bool OpenGLRenderer::createFboLayer(Layer* layer, Rect& bounds, sp<Snapshot> snapshot,
469        GLuint previousFbo) {
470    layer->fbo = mCaches.fboCache.get();
471
472#if RENDER_LAYERS_AS_REGIONS
473    snapshot->region = &snapshot->layer->region;
474    snapshot->flags |= Snapshot::kFlagFboTarget;
475#endif
476
477    Rect clip(bounds);
478    snapshot->transform->mapRect(clip);
479    clip.intersect(*snapshot->clipRect);
480    clip.snapToPixelBoundaries();
481    clip.intersect(snapshot->previous->viewport);
482
483    mat4 inverse;
484    inverse.loadInverse(*mSnapshot->transform);
485
486    inverse.mapRect(clip);
487    clip.snapToPixelBoundaries();
488    clip.intersect(bounds);
489    clip.translate(-bounds.left, -bounds.top);
490
491    snapshot->flags |= Snapshot::kFlagIsFboLayer;
492    snapshot->fbo = layer->fbo;
493    snapshot->resetTransform(-bounds.left, -bounds.top, 0.0f);
494    snapshot->resetClip(clip.left, clip.top, clip.right, clip.bottom);
495    snapshot->viewport.set(0.0f, 0.0f, bounds.getWidth(), bounds.getHeight());
496    snapshot->height = bounds.getHeight();
497    snapshot->flags |= Snapshot::kFlagDirtyOrtho;
498    snapshot->orthoMatrix.load(mOrthoMatrix);
499
500    // Bind texture to FBO
501    glBindFramebuffer(GL_FRAMEBUFFER, layer->fbo);
502    glBindTexture(GL_TEXTURE_2D, layer->texture);
503
504    // Initialize the texture if needed
505    if (layer->empty) {
506        layer->empty = false;
507        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, layer->width, layer->height, 0,
508                GL_RGBA, GL_UNSIGNED_BYTE, NULL);
509    }
510
511    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
512            layer->texture, 0);
513
514#if DEBUG_LAYERS_AS_REGIONS
515    GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
516    if (status != GL_FRAMEBUFFER_COMPLETE) {
517        LOGE("Framebuffer incomplete (GL error code 0x%x)", status);
518
519        glBindFramebuffer(GL_FRAMEBUFFER, previousFbo);
520        glDeleteTextures(1, &layer->texture);
521        mCaches.fboCache.put(layer->fbo);
522
523        delete layer;
524
525        return false;
526    }
527#endif
528
529    // Clear the FBO, expand the clear region by 1 to get nice bilinear filtering
530    glScissor(clip.left - 1.0f, bounds.getHeight() - clip.bottom - 1.0f,
531            clip.getWidth() + 2.0f, clip.getHeight() + 2.0f);
532    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
533    glClear(GL_COLOR_BUFFER_BIT);
534
535    dirtyClip();
536
537    // Change the ortho projection
538    glViewport(0, 0, bounds.getWidth(), bounds.getHeight());
539    mOrthoMatrix.loadOrtho(0.0f, bounds.getWidth(), bounds.getHeight(), 0.0f, -1.0f, 1.0f);
540
541    return true;
542}
543
544/**
545 * Read the documentation of createLayer() before doing anything in this method.
546 */
547void OpenGLRenderer::composeLayer(sp<Snapshot> current, sp<Snapshot> previous) {
548    if (!current->layer) {
549        LOGE("Attempting to compose a layer that does not exist");
550        return;
551    }
552
553    const bool fboLayer = current->flags & Snapshot::kFlagIsFboLayer;
554
555    if (fboLayer) {
556        // Unbind current FBO and restore previous one
557        glBindFramebuffer(GL_FRAMEBUFFER, previous->fbo);
558    }
559
560    Layer* layer = current->layer;
561    const Rect& rect = layer->layer;
562
563    if (!fboLayer && layer->alpha < 255) {
564        drawColorRect(rect.left, rect.top, rect.right, rect.bottom,
565                layer->alpha << 24, SkXfermode::kDstIn_Mode, true);
566        // Required below, composeLayerRect() will divide by 255
567        layer->alpha = 255;
568    }
569
570    mCaches.unbindMeshBuffer();
571
572    glActiveTexture(gTextureUnits[0]);
573
574    // When the layer is stored in an FBO, we can save a bit of fillrate by
575    // drawing only the dirty region
576    if (fboLayer) {
577        dirtyLayer(rect.left, rect.top, rect.right, rect.bottom, *previous->transform);
578        if (layer->colorFilter) {
579            setupColorFilter(layer->colorFilter);
580        }
581        composeLayerRegion(layer, rect);
582        if (layer->colorFilter) {
583            resetColorFilter();
584        }
585    } else {
586        if (!rect.isEmpty()) {
587            dirtyLayer(rect.left, rect.top, rect.right, rect.bottom);
588            composeLayerRect(layer, rect, true);
589        }
590    }
591
592    if (fboLayer) {
593        // Detach the texture from the FBO
594        glBindFramebuffer(GL_FRAMEBUFFER, current->fbo);
595        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 0, 0);
596        glBindFramebuffer(GL_FRAMEBUFFER, previous->fbo);
597
598        // Put the FBO name back in the cache, if it doesn't fit, it will be destroyed
599        mCaches.fboCache.put(current->fbo);
600    }
601
602    dirtyClip();
603
604    // Failing to add the layer to the cache should happen only if the layer is too large
605    if (!mCaches.layerCache.put(layer)) {
606        LAYER_LOGD("Deleting layer");
607        glDeleteTextures(1, &layer->texture);
608        delete layer;
609    }
610}
611
612void OpenGLRenderer::composeLayerRect(Layer* layer, const Rect& rect, bool swap) {
613    const Rect& texCoords = layer->texCoords;
614    resetDrawTextureTexCoords(texCoords.left, texCoords.top, texCoords.right, texCoords.bottom);
615
616    drawTextureMesh(rect.left, rect.top, rect.right, rect.bottom, layer->texture,
617            layer->alpha / 255.0f, layer->mode, layer->blend, &mMeshVertices[0].position[0],
618            &mMeshVertices[0].texture[0], GL_TRIANGLE_STRIP, gMeshCount, swap, swap);
619
620    resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
621}
622
623void OpenGLRenderer::composeLayerRegion(Layer* layer, const Rect& rect) {
624#if RENDER_LAYERS_AS_REGIONS
625    if (layer->region.isRect()) {
626        composeLayerRect(layer, rect);
627        layer->region.clear();
628        return;
629    }
630
631    if (!layer->region.isEmpty()) {
632        size_t count;
633        const android::Rect* rects = layer->region.getArray(&count);
634
635        const float alpha = layer->alpha / 255.0f;
636        const float texX = 1.0f / float(layer->width);
637        const float texY = 1.0f / float(layer->height);
638        const float height = rect.getHeight();
639
640        TextureVertex* mesh = mCaches.getRegionMesh();
641        GLsizei numQuads = 0;
642
643        setupDraw();
644        setupDrawWithTexture();
645        setupDrawColor(alpha, alpha, alpha, alpha);
646        setupDrawColorFilter();
647        setupDrawBlending(layer->blend || layer->alpha < 255, layer->mode, false);
648        setupDrawProgram();
649        setupDrawDirtyRegionsDisabled();
650        setupDrawPureColorUniforms();
651        setupDrawColorFilterUniforms();
652        setupDrawTexture(layer->texture);
653        setupDrawModelViewTranslate(rect.left, rect.top, rect.right, rect.bottom);
654        setupDrawMesh(&mesh[0].position[0], &mesh[0].texture[0]);
655
656        for (size_t i = 0; i < count; i++) {
657            const android::Rect* r = &rects[i];
658
659            const float u1 = r->left * texX;
660            const float v1 = (height - r->top) * texY;
661            const float u2 = r->right * texX;
662            const float v2 = (height - r->bottom) * texY;
663
664            // TODO: Reject quads outside of the clip
665            TextureVertex::set(mesh++, r->left, r->top, u1, v1);
666            TextureVertex::set(mesh++, r->right, r->top, u2, v1);
667            TextureVertex::set(mesh++, r->left, r->bottom, u1, v2);
668            TextureVertex::set(mesh++, r->right, r->bottom, u2, v2);
669
670            numQuads++;
671
672            if (numQuads >= REGION_MESH_QUAD_COUNT) {
673                glDrawElements(GL_TRIANGLES, numQuads * 6, GL_UNSIGNED_SHORT, NULL);
674                numQuads = 0;
675                mesh = mCaches.getRegionMesh();
676            }
677        }
678
679        if (numQuads > 0) {
680            glDrawElements(GL_TRIANGLES, numQuads * 6, GL_UNSIGNED_SHORT, NULL);
681        }
682
683        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
684        finishDrawTexture();
685
686#if DEBUG_LAYERS_AS_REGIONS
687        drawRegionRects(layer->region);
688#endif
689
690        layer->region.clear();
691    }
692#else
693    composeLayerRect(layer, rect);
694#endif
695}
696
697void OpenGLRenderer::drawRegionRects(const Region& region) {
698#if DEBUG_LAYERS_AS_REGIONS
699    size_t count;
700    const android::Rect* rects = region.getArray(&count);
701
702    uint32_t colors[] = {
703            0x7fff0000, 0x7f00ff00,
704            0x7f0000ff, 0x7fff00ff,
705    };
706
707    int offset = 0;
708    int32_t top = rects[0].top;
709
710    for (size_t i = 0; i < count; i++) {
711        if (top != rects[i].top) {
712            offset ^= 0x2;
713            top = rects[i].top;
714        }
715
716        Rect r(rects[i].left, rects[i].top, rects[i].right, rects[i].bottom);
717        drawColorRect(r.left, r.top, r.right, r.bottom, colors[offset + (i & 0x1)],
718                SkXfermode::kSrcOver_Mode);
719    }
720#endif
721}
722
723void OpenGLRenderer::dirtyLayer(const float left, const float top,
724        const float right, const float bottom, const mat4 transform) {
725#if RENDER_LAYERS_AS_REGIONS
726    if (hasLayer()) {
727        Rect bounds(left, top, right, bottom);
728        transform.mapRect(bounds);
729        dirtyLayerUnchecked(bounds, getRegion());
730    }
731#endif
732}
733
734void OpenGLRenderer::dirtyLayer(const float left, const float top,
735        const float right, const float bottom) {
736#if RENDER_LAYERS_AS_REGIONS
737    if (hasLayer()) {
738        Rect bounds(left, top, right, bottom);
739        dirtyLayerUnchecked(bounds, getRegion());
740    }
741#endif
742}
743
744void OpenGLRenderer::dirtyLayerUnchecked(Rect& bounds, Region* region) {
745#if RENDER_LAYERS_AS_REGIONS
746    if (bounds.intersect(*mSnapshot->clipRect)) {
747        bounds.snapToPixelBoundaries();
748        android::Rect dirty(bounds.left, bounds.top, bounds.right, bounds.bottom);
749        if (!dirty.isEmpty()) {
750            region->orSelf(dirty);
751        }
752    }
753#endif
754}
755
756void OpenGLRenderer::clearLayerRegions() {
757    if (mLayers.size() == 0 || mSnapshot->isIgnored()) return;
758
759    Rect clipRect(*mSnapshot->clipRect);
760    clipRect.snapToPixelBoundaries();
761
762    for (uint32_t i = 0; i < mLayers.size(); i++) {
763        Rect* bounds = mLayers.itemAt(i);
764        if (clipRect.intersects(*bounds)) {
765            // Clear the framebuffer where the layer will draw
766            glScissor(bounds->left, mSnapshot->height - bounds->bottom,
767                    bounds->getWidth(), bounds->getHeight());
768            glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
769            glClear(GL_COLOR_BUFFER_BIT);
770
771            // Restore the clip
772            dirtyClip();
773        }
774
775        delete bounds;
776    }
777
778    mLayers.clear();
779}
780
781///////////////////////////////////////////////////////////////////////////////
782// Transforms
783///////////////////////////////////////////////////////////////////////////////
784
785void OpenGLRenderer::translate(float dx, float dy) {
786    mSnapshot->transform->translate(dx, dy, 0.0f);
787}
788
789void OpenGLRenderer::rotate(float degrees) {
790    mSnapshot->transform->rotate(degrees, 0.0f, 0.0f, 1.0f);
791}
792
793void OpenGLRenderer::scale(float sx, float sy) {
794    mSnapshot->transform->scale(sx, sy, 1.0f);
795}
796
797void OpenGLRenderer::skew(float sx, float sy) {
798    mSnapshot->transform->skew(sx, sy);
799}
800
801void OpenGLRenderer::setMatrix(SkMatrix* matrix) {
802    mSnapshot->transform->load(*matrix);
803}
804
805const float* OpenGLRenderer::getMatrix() const {
806    if (mSnapshot->fbo != 0) {
807        return &mSnapshot->transform->data[0];
808    }
809    return &mIdentity.data[0];
810}
811
812void OpenGLRenderer::getMatrix(SkMatrix* matrix) {
813    mSnapshot->transform->copyTo(*matrix);
814}
815
816void OpenGLRenderer::concatMatrix(SkMatrix* matrix) {
817    SkMatrix transform;
818    mSnapshot->transform->copyTo(transform);
819    transform.preConcat(*matrix);
820    mSnapshot->transform->load(transform);
821}
822
823///////////////////////////////////////////////////////////////////////////////
824// Clipping
825///////////////////////////////////////////////////////////////////////////////
826
827void OpenGLRenderer::setScissorFromClip() {
828    Rect clip(*mSnapshot->clipRect);
829    clip.snapToPixelBoundaries();
830    glScissor(clip.left, mSnapshot->height - clip.bottom, clip.getWidth(), clip.getHeight());
831    mDirtyClip = false;
832}
833
834const Rect& OpenGLRenderer::getClipBounds() {
835    return mSnapshot->getLocalClip();
836}
837
838bool OpenGLRenderer::quickReject(float left, float top, float right, float bottom) {
839    if (mSnapshot->isIgnored()) {
840        return true;
841    }
842
843    Rect r(left, top, right, bottom);
844    mSnapshot->transform->mapRect(r);
845    r.snapToPixelBoundaries();
846
847    Rect clipRect(*mSnapshot->clipRect);
848    clipRect.snapToPixelBoundaries();
849
850    return !clipRect.intersects(r);
851}
852
853bool OpenGLRenderer::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {
854    bool clipped = mSnapshot->clip(left, top, right, bottom, op);
855    if (clipped) {
856        dirtyClip();
857    }
858    return !mSnapshot->clipRect->isEmpty();
859}
860
861///////////////////////////////////////////////////////////////////////////////
862// Drawing commands
863///////////////////////////////////////////////////////////////////////////////
864
865void OpenGLRenderer::setupDraw() {
866    clearLayerRegions();
867    if (mDirtyClip) {
868        setScissorFromClip();
869    }
870    mDescription.reset();
871    mSetShaderColor = false;
872    mColorSet = false;
873    mColorA = mColorR = mColorG = mColorB = 0.0f;
874    mTextureUnit = 0;
875    mTrackDirtyRegions = true;
876    mTexCoordsSlot = -1;
877}
878
879void OpenGLRenderer::setupDrawWithTexture(bool isAlpha8) {
880    mDescription.hasTexture = true;
881    mDescription.hasAlpha8Texture = isAlpha8;
882}
883
884void OpenGLRenderer::setupDrawColor(int color) {
885    setupDrawColor(color, (color >> 24) & 0xFF);
886}
887
888void OpenGLRenderer::setupDrawColor(int color, int alpha) {
889    mColorA = alpha / 255.0f;
890    const float a = mColorA / 255.0f;
891    mColorR = a * ((color >> 16) & 0xFF);
892    mColorG = a * ((color >>  8) & 0xFF);
893    mColorB = a * ((color      ) & 0xFF);
894    mColorSet = true;
895    mSetShaderColor = mDescription.setColor(mColorR, mColorG, mColorB, mColorA);
896}
897
898void OpenGLRenderer::setupDrawAlpha8Color(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.setAlpha8Color(mColorR, mColorG, mColorB, mColorA);
906}
907
908void OpenGLRenderer::setupDrawColor(float r, float g, float b, float a) {
909    mColorA = a;
910    mColorR = r;
911    mColorG = g;
912    mColorB = b;
913    mColorSet = true;
914    mSetShaderColor = mDescription.setColor(r, g, b, a);
915}
916
917void OpenGLRenderer::setupDrawAlpha8Color(float r, float g, float b, float a) {
918    mColorA = a;
919    mColorR = r;
920    mColorG = g;
921    mColorB = b;
922    mColorSet = true;
923    mSetShaderColor = mDescription.setAlpha8Color(r, g, b, a);
924}
925
926void OpenGLRenderer::setupDrawShader() {
927    if (mShader) {
928        mShader->describe(mDescription, mCaches.extensions);
929    }
930}
931
932void OpenGLRenderer::setupDrawColorFilter() {
933    if (mColorFilter) {
934        mColorFilter->describe(mDescription, mCaches.extensions);
935    }
936}
937
938void OpenGLRenderer::setupDrawBlending(SkXfermode::Mode mode, bool swapSrcDst) {
939    chooseBlending((mColorSet && mColorA < 1.0f) || (mShader && mShader->blend()), mode,
940            mDescription, swapSrcDst);
941}
942
943void OpenGLRenderer::setupDrawBlending(bool blend, SkXfermode::Mode mode, bool swapSrcDst) {
944    chooseBlending(blend || (mColorSet && mColorA < 1.0f) || (mShader && mShader->blend()), mode,
945            mDescription, swapSrcDst);
946}
947
948void OpenGLRenderer::setupDrawProgram() {
949    useProgram(mCaches.programCache.get(mDescription));
950}
951
952void OpenGLRenderer::setupDrawDirtyRegionsDisabled() {
953    mTrackDirtyRegions = false;
954}
955
956void OpenGLRenderer::setupDrawModelViewTranslate(float left, float top, float right, float bottom,
957        bool ignoreTransform) {
958    mModelView.loadTranslate(left, top, 0.0f);
959    if (!ignoreTransform) {
960        mCaches.currentProgram->set(mOrthoMatrix, mModelView, *mSnapshot->transform);
961        if (mTrackDirtyRegions) dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
962    } else {
963        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mIdentity);
964        if (mTrackDirtyRegions) dirtyLayer(left, top, right, bottom);
965    }
966}
967
968void OpenGLRenderer::setupDrawModelViewIdentity() {
969    mCaches.currentProgram->set(mOrthoMatrix, mIdentity, *mSnapshot->transform);
970}
971
972void OpenGLRenderer::setupDrawModelView(float left, float top, float right, float bottom,
973        bool ignoreTransform, bool ignoreModelView) {
974    if (!ignoreModelView) {
975        mModelView.loadTranslate(left, top, 0.0f);
976        mModelView.scale(right - left, bottom - top, 1.0f);
977    } else {
978        mModelView.loadIdentity();
979    }
980    bool dirty = right - left > 0.0f && bottom - top > 0.0f;
981    if (!ignoreTransform) {
982        mCaches.currentProgram->set(mOrthoMatrix, mModelView, *mSnapshot->transform);
983        if (mTrackDirtyRegions && dirty) {
984            dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
985        }
986    } else {
987        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mIdentity);
988        if (mTrackDirtyRegions && dirty) dirtyLayer(left, top, right, bottom);
989    }
990}
991
992void OpenGLRenderer::setupDrawColorUniforms() {
993    if (mColorSet || (mShader && mSetShaderColor)) {
994        mCaches.currentProgram->setColor(mColorR, mColorG, mColorB, mColorA);
995    }
996}
997
998void OpenGLRenderer::setupDrawPureColorUniforms() {
999    if (mSetShaderColor) {
1000        mCaches.currentProgram->setColor(mColorR, mColorG, mColorB, mColorA);
1001    }
1002}
1003
1004void OpenGLRenderer::setupDrawShaderUniforms(bool ignoreTransform) {
1005    if (mShader) {
1006        if (ignoreTransform) {
1007            mModelView.loadInverse(*mSnapshot->transform);
1008        }
1009        mShader->setupProgram(mCaches.currentProgram, mModelView, *mSnapshot, &mTextureUnit);
1010    }
1011}
1012
1013void OpenGLRenderer::setupDrawShaderIdentityUniforms() {
1014    if (mShader) {
1015        mShader->setupProgram(mCaches.currentProgram, mIdentity, *mSnapshot, &mTextureUnit);
1016    }
1017}
1018
1019void OpenGLRenderer::setupDrawColorFilterUniforms() {
1020    if (mColorFilter) {
1021        mColorFilter->setupProgram(mCaches.currentProgram);
1022    }
1023}
1024
1025void OpenGLRenderer::setupDrawSimpleMesh() {
1026    mCaches.bindMeshBuffer();
1027    glVertexAttribPointer(mCaches.currentProgram->position, 2, GL_FLOAT, GL_FALSE,
1028            gMeshStride, 0);
1029}
1030
1031void OpenGLRenderer::setupDrawTexture(GLuint texture) {
1032    bindTexture(texture);
1033    glUniform1i(mCaches.currentProgram->getUniform("sampler"), mTextureUnit++);
1034
1035    mTexCoordsSlot = mCaches.currentProgram->getAttrib("texCoords");
1036    glEnableVertexAttribArray(mTexCoordsSlot);
1037}
1038
1039void OpenGLRenderer::setupDrawMesh(GLvoid* vertices, GLvoid* texCoords, GLuint vbo) {
1040    if (!vertices) {
1041        mCaches.bindMeshBuffer(vbo == 0 ? mCaches.meshBuffer : vbo);
1042    } else {
1043        mCaches.unbindMeshBuffer();
1044    }
1045    glVertexAttribPointer(mCaches.currentProgram->position, 2, GL_FLOAT, GL_FALSE,
1046            gMeshStride, vertices);
1047    if (mTexCoordsSlot >= 0) {
1048        glVertexAttribPointer(mTexCoordsSlot, 2, GL_FLOAT, GL_FALSE, gMeshStride, texCoords);
1049    }
1050}
1051
1052void OpenGLRenderer::finishDrawTexture() {
1053    glDisableVertexAttribArray(mTexCoordsSlot);
1054}
1055
1056///////////////////////////////////////////////////////////////////////////////
1057// Drawing
1058///////////////////////////////////////////////////////////////////////////////
1059
1060bool OpenGLRenderer::drawDisplayList(DisplayList* displayList, uint32_t level) {
1061    // All the usual checks and setup operations (quickReject, setupDraw, etc.)
1062    // will be performed by the display list itself
1063    if (displayList) {
1064        return displayList->replay(*this, level);
1065    }
1066    return false;
1067}
1068
1069void OpenGLRenderer::drawBitmap(SkBitmap* bitmap, float left, float top, SkPaint* paint) {
1070    const float right = left + bitmap->width();
1071    const float bottom = top + bitmap->height();
1072
1073    if (quickReject(left, top, right, bottom)) {
1074        return;
1075    }
1076
1077    glActiveTexture(gTextureUnits[0]);
1078    Texture* texture = mCaches.textureCache.get(bitmap);
1079    if (!texture) return;
1080    const AutoTexture autoCleanup(texture);
1081
1082    drawTextureRect(left, top, right, bottom, texture, paint);
1083}
1084
1085void OpenGLRenderer::drawBitmap(SkBitmap* bitmap, SkMatrix* matrix, SkPaint* paint) {
1086    Rect r(0.0f, 0.0f, bitmap->width(), bitmap->height());
1087    const mat4 transform(*matrix);
1088    transform.mapRect(r);
1089
1090    if (quickReject(r.left, r.top, r.right, r.bottom)) {
1091        return;
1092    }
1093
1094    glActiveTexture(gTextureUnits[0]);
1095    Texture* texture = mCaches.textureCache.get(bitmap);
1096    if (!texture) return;
1097    const AutoTexture autoCleanup(texture);
1098
1099    // This could be done in a cheaper way, all we need is pass the matrix
1100    // to the vertex shader. The save/restore is a bit overkill.
1101    save(SkCanvas::kMatrix_SaveFlag);
1102    concatMatrix(matrix);
1103    drawTextureRect(0.0f, 0.0f, bitmap->width(), bitmap->height(), texture, paint);
1104    restore();
1105}
1106
1107void OpenGLRenderer::drawBitmapMesh(SkBitmap* bitmap, int meshWidth, int meshHeight,
1108        float* vertices, int* colors, SkPaint* paint) {
1109    // TODO: Do a quickReject
1110    if (!vertices || mSnapshot->isIgnored()) {
1111        return;
1112    }
1113
1114    glActiveTexture(gTextureUnits[0]);
1115    Texture* texture = mCaches.textureCache.get(bitmap);
1116    if (!texture) return;
1117    const AutoTexture autoCleanup(texture);
1118    setTextureWrapModes(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
1119
1120    int alpha;
1121    SkXfermode::Mode mode;
1122    getAlphaAndMode(paint, &alpha, &mode);
1123
1124    const uint32_t count = meshWidth * meshHeight * 6;
1125
1126    float left = FLT_MAX;
1127    float top = FLT_MAX;
1128    float right = FLT_MIN;
1129    float bottom = FLT_MIN;
1130
1131#if RENDER_LAYERS_AS_REGIONS
1132    bool hasActiveLayer = hasLayer();
1133#else
1134    bool hasActiveLayer = false;
1135#endif
1136
1137    // TODO: Support the colors array
1138    TextureVertex mesh[count];
1139    TextureVertex* vertex = mesh;
1140    for (int32_t y = 0; y < meshHeight; y++) {
1141        for (int32_t x = 0; x < meshWidth; x++) {
1142            uint32_t i = (y * (meshWidth + 1) + x) * 2;
1143
1144            float u1 = float(x) / meshWidth;
1145            float u2 = float(x + 1) / meshWidth;
1146            float v1 = float(y) / meshHeight;
1147            float v2 = float(y + 1) / meshHeight;
1148
1149            int ax = i + (meshWidth + 1) * 2;
1150            int ay = ax + 1;
1151            int bx = i;
1152            int by = bx + 1;
1153            int cx = i + 2;
1154            int cy = cx + 1;
1155            int dx = i + (meshWidth + 1) * 2 + 2;
1156            int dy = dx + 1;
1157
1158            TextureVertex::set(vertex++, vertices[ax], vertices[ay], u1, v2);
1159            TextureVertex::set(vertex++, vertices[bx], vertices[by], u1, v1);
1160            TextureVertex::set(vertex++, vertices[cx], vertices[cy], u2, v1);
1161
1162            TextureVertex::set(vertex++, vertices[ax], vertices[ay], u1, v2);
1163            TextureVertex::set(vertex++, vertices[cx], vertices[cy], u2, v1);
1164            TextureVertex::set(vertex++, vertices[dx], vertices[dy], u2, v2);
1165
1166#if RENDER_LAYERS_AS_REGIONS
1167            if (hasActiveLayer) {
1168                // TODO: This could be optimized to avoid unnecessary ops
1169                left = fminf(left, fminf(vertices[ax], fminf(vertices[bx], vertices[cx])));
1170                top = fminf(top, fminf(vertices[ay], fminf(vertices[by], vertices[cy])));
1171                right = fmaxf(right, fmaxf(vertices[ax], fmaxf(vertices[bx], vertices[cx])));
1172                bottom = fmaxf(bottom, fmaxf(vertices[ay], fmaxf(vertices[by], vertices[cy])));
1173            }
1174#endif
1175        }
1176    }
1177
1178#if RENDER_LAYERS_AS_REGIONS
1179    if (hasActiveLayer) {
1180        dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
1181    }
1182#endif
1183
1184    drawTextureMesh(0.0f, 0.0f, 1.0f, 1.0f, texture->id, alpha / 255.0f,
1185            mode, texture->blend, &mesh[0].position[0], &mesh[0].texture[0],
1186            GL_TRIANGLES, count, false, false, 0, false, false);
1187}
1188
1189void OpenGLRenderer::drawBitmap(SkBitmap* bitmap,
1190         float srcLeft, float srcTop, float srcRight, float srcBottom,
1191         float dstLeft, float dstTop, float dstRight, float dstBottom,
1192         SkPaint* paint) {
1193    if (quickReject(dstLeft, dstTop, dstRight, dstBottom)) {
1194        return;
1195    }
1196
1197    glActiveTexture(gTextureUnits[0]);
1198    Texture* texture = mCaches.textureCache.get(bitmap);
1199    if (!texture) return;
1200    const AutoTexture autoCleanup(texture);
1201    setTextureWrapModes(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
1202
1203    const float width = texture->width;
1204    const float height = texture->height;
1205
1206    const float u1 = srcLeft / width;
1207    const float v1 = srcTop / height;
1208    const float u2 = srcRight / width;
1209    const float v2 = srcBottom / height;
1210
1211    mCaches.unbindMeshBuffer();
1212    resetDrawTextureTexCoords(u1, v1, u2, v2);
1213
1214    int alpha;
1215    SkXfermode::Mode mode;
1216    getAlphaAndMode(paint, &alpha, &mode);
1217
1218    if (mSnapshot->transform->isPureTranslate()) {
1219        const float x = (int) floorf(dstLeft + mSnapshot->transform->getTranslateX() + 0.5f);
1220        const float y = (int) floorf(dstTop + mSnapshot->transform->getTranslateY() + 0.5f);
1221
1222        drawTextureMesh(x, y, x + (dstRight - dstLeft), y + (dstBottom - dstTop),
1223                texture->id, alpha / 255.0f, mode, texture->blend,
1224                &mMeshVertices[0].position[0], &mMeshVertices[0].texture[0],
1225                GL_TRIANGLE_STRIP, gMeshCount, false, true);
1226    } else {
1227        drawTextureMesh(dstLeft, dstTop, dstRight, dstBottom, texture->id, alpha / 255.0f,
1228                mode, texture->blend, &mMeshVertices[0].position[0], &mMeshVertices[0].texture[0],
1229                GL_TRIANGLE_STRIP, gMeshCount);
1230    }
1231
1232    resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
1233}
1234
1235void OpenGLRenderer::drawPatch(SkBitmap* bitmap, const int32_t* xDivs, const int32_t* yDivs,
1236        const uint32_t* colors, uint32_t width, uint32_t height, int8_t numColors,
1237        float left, float top, float right, float bottom, SkPaint* paint) {
1238    if (quickReject(left, top, right, bottom)) {
1239        return;
1240    }
1241
1242    glActiveTexture(gTextureUnits[0]);
1243    Texture* texture = mCaches.textureCache.get(bitmap);
1244    if (!texture) return;
1245    const AutoTexture autoCleanup(texture);
1246    setTextureWrapModes(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
1247
1248    int alpha;
1249    SkXfermode::Mode mode;
1250    getAlphaAndMode(paint, &alpha, &mode);
1251
1252    const Patch* mesh = mCaches.patchCache.get(bitmap->width(), bitmap->height(),
1253            right - left, bottom - top, xDivs, yDivs, colors, width, height, numColors);
1254
1255    if (mesh && mesh->verticesCount > 0) {
1256        const bool pureTranslate = mSnapshot->transform->isPureTranslate();
1257#if RENDER_LAYERS_AS_REGIONS
1258        // Mark the current layer dirty where we are going to draw the patch
1259        if (hasLayer() && mesh->hasEmptyQuads) {
1260            const float offsetX = left + mSnapshot->transform->getTranslateX();
1261            const float offsetY = top + mSnapshot->transform->getTranslateY();
1262            const size_t count = mesh->quads.size();
1263            for (size_t i = 0; i < count; i++) {
1264                const Rect& bounds = mesh->quads.itemAt(i);
1265                if (pureTranslate) {
1266                    const float x = (int) floorf(bounds.left + offsetX + 0.5f);
1267                    const float y = (int) floorf(bounds.top + offsetY + 0.5f);
1268                    dirtyLayer(x, y, x + bounds.getWidth(), y + bounds.getHeight());
1269                } else {
1270                    dirtyLayer(left + bounds.left, top + bounds.top,
1271                            left + bounds.right, top + bounds.bottom, *mSnapshot->transform);
1272                }
1273            }
1274        }
1275#endif
1276
1277        if (pureTranslate) {
1278            const float x = (int) floorf(left + mSnapshot->transform->getTranslateX() + 0.5f);
1279            const float y = (int) floorf(top + mSnapshot->transform->getTranslateY() + 0.5f);
1280
1281            drawTextureMesh(x, y, x + right - left, y + bottom - top, texture->id, alpha / 255.0f,
1282                    mode, texture->blend, (GLvoid*) 0, (GLvoid*) gMeshTextureOffset,
1283                    GL_TRIANGLES, mesh->verticesCount, false, true, mesh->meshBuffer,
1284                    true, !mesh->hasEmptyQuads);
1285        } else {
1286            drawTextureMesh(left, top, right, bottom, texture->id, alpha / 255.0f,
1287                    mode, texture->blend, (GLvoid*) 0, (GLvoid*) gMeshTextureOffset,
1288                    GL_TRIANGLES, mesh->verticesCount, false, false, mesh->meshBuffer,
1289                    true, !mesh->hasEmptyQuads);
1290        }
1291    }
1292}
1293
1294void OpenGLRenderer::drawLines(float* points, int count, SkPaint* paint) {
1295    if (mSnapshot->isIgnored()) return;
1296
1297    const bool isAA = paint->isAntiAlias();
1298    const float strokeWidth = paint->getStrokeWidth() * 0.5f;
1299    // A stroke width of 0 has a special meaningin Skia:
1300    // it draws an unscaled 1px wide line
1301    const bool isHairLine = paint->getStrokeWidth() == 0.0f;
1302
1303    int alpha;
1304    SkXfermode::Mode mode;
1305    getAlphaAndMode(paint, &alpha, &mode);
1306
1307    int verticesCount = count >> 2;
1308    int generatedVerticesCount = 0;
1309    if (!isHairLine) {
1310        // TODO: AA needs more vertices
1311        verticesCount *= 6;
1312    } else {
1313        // TODO: AA will be different
1314        verticesCount *= 2;
1315    }
1316
1317    TextureVertex lines[verticesCount];
1318    TextureVertex* vertex = &lines[0];
1319
1320    setupDraw();
1321    setupDrawColor(paint->getColor(), alpha);
1322    setupDrawColorFilter();
1323    setupDrawShader();
1324    setupDrawBlending(mode);
1325    setupDrawProgram();
1326    setupDrawModelViewIdentity();
1327    setupDrawColorUniforms();
1328    setupDrawColorFilterUniforms();
1329    setupDrawShaderIdentityUniforms();
1330    setupDrawMesh(vertex);
1331
1332    if (!isHairLine) {
1333        // TODO: Handle the AA case
1334        for (int i = 0; i < count; i += 4) {
1335            // a = start point, b = end point
1336            vec2 a(points[i], points[i + 1]);
1337            vec2 b(points[i + 2], points[i + 3]);
1338
1339            // Bias to snap to the same pixels as Skia
1340            a += 0.375;
1341            b += 0.375;
1342
1343            // Find the normal to the line
1344            vec2 n = (b - a).copyNormalized() * strokeWidth;
1345            float x = n.x;
1346            n.x = -n.y;
1347            n.y = x;
1348
1349            // Four corners of the rectangle defining a thick line
1350            vec2 p1 = a - n;
1351            vec2 p2 = a + n;
1352            vec2 p3 = b + n;
1353            vec2 p4 = b - n;
1354
1355            const float left = fmin(p1.x, fmin(p2.x, fmin(p3.x, p4.x)));
1356            const float right = fmax(p1.x, fmax(p2.x, fmax(p3.x, p4.x)));
1357            const float top = fmin(p1.y, fmin(p2.y, fmin(p3.y, p4.y)));
1358            const float bottom = fmax(p1.y, fmax(p2.y, fmax(p3.y, p4.y)));
1359
1360            if (!quickReject(left, top, right, bottom)) {
1361                // Draw the line as 2 triangles, could be optimized
1362                // by using only 4 vertices and the correct indices
1363                // Also we should probably used non textured vertices
1364                // when line AA is disabled to save on bandwidth
1365                TextureVertex::set(vertex++, p1.x, p1.y, 0.0f, 0.0f);
1366                TextureVertex::set(vertex++, p2.x, p2.y, 0.0f, 0.0f);
1367                TextureVertex::set(vertex++, p3.x, p3.y, 0.0f, 0.0f);
1368                TextureVertex::set(vertex++, p1.x, p1.y, 0.0f, 0.0f);
1369                TextureVertex::set(vertex++, p3.x, p3.y, 0.0f, 0.0f);
1370                TextureVertex::set(vertex++, p4.x, p4.y, 0.0f, 0.0f);
1371
1372                generatedVerticesCount += 6;
1373
1374                dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
1375            }
1376        }
1377
1378        if (generatedVerticesCount > 0) {
1379            // GL_LINE does not give the result we want to match Skia
1380            glDrawArrays(GL_TRIANGLES, 0, generatedVerticesCount);
1381        }
1382    } else {
1383        // TODO: Handle the AA case
1384        for (int i = 0; i < count; i += 4) {
1385            const float left = fmin(points[i], points[i + 1]);
1386            const float right = fmax(points[i], points[i + 1]);
1387            const float top = fmin(points[i + 2], points[i + 3]);
1388            const float bottom = fmax(points[i + 2], points[i + 3]);
1389
1390            if (!quickReject(left, top, right, bottom)) {
1391                TextureVertex::set(vertex++, points[i], points[i + 1], 0.0f, 0.0f);
1392                TextureVertex::set(vertex++, points[i + 2], points[i + 3], 0.0f, 0.0f);
1393
1394                generatedVerticesCount += 2;
1395
1396                dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
1397            }
1398        }
1399
1400        if (generatedVerticesCount > 0) {
1401            glLineWidth(1.0f);
1402            glDrawArrays(GL_LINES, 0, generatedVerticesCount);
1403        }
1404    }
1405}
1406
1407void OpenGLRenderer::drawColor(int color, SkXfermode::Mode mode) {
1408    // No need to check against the clip, we fill the clip region
1409    if (mSnapshot->isIgnored()) return;
1410
1411    Rect& clip(*mSnapshot->clipRect);
1412    clip.snapToPixelBoundaries();
1413
1414    drawColorRect(clip.left, clip.top, clip.right, clip.bottom, color, mode, true);
1415}
1416
1417void OpenGLRenderer::drawShape(float left, float top, const PathTexture* texture, SkPaint* paint) {
1418    if (!texture) return;
1419    const AutoTexture autoCleanup(texture);
1420
1421    const float x = left + texture->left - texture->offset;
1422    const float y = top + texture->top - texture->offset;
1423
1424    drawPathTexture(texture, x, y, paint);
1425}
1426
1427void OpenGLRenderer::drawRoundRect(float left, float top, float right, float bottom,
1428        float rx, float ry, SkPaint* paint) {
1429    if (mSnapshot->isIgnored()) return;
1430
1431    glActiveTexture(gTextureUnits[0]);
1432    const PathTexture* texture = mCaches.roundRectShapeCache.getRoundRect(
1433            right - left, bottom - top, rx, ry, paint);
1434    drawShape(left, top, texture, paint);
1435}
1436
1437void OpenGLRenderer::drawCircle(float x, float y, float radius, SkPaint* paint) {
1438    if (mSnapshot->isIgnored()) return;
1439
1440    glActiveTexture(gTextureUnits[0]);
1441    const PathTexture* texture = mCaches.circleShapeCache.getCircle(radius, paint);
1442    drawShape(x - radius, y - radius, texture, paint);
1443}
1444
1445void OpenGLRenderer::drawOval(float left, float top, float right, float bottom, SkPaint* paint) {
1446    if (mSnapshot->isIgnored()) return;
1447
1448    glActiveTexture(gTextureUnits[0]);
1449    const PathTexture* texture = mCaches.ovalShapeCache.getOval(right - left, bottom - top, paint);
1450    drawShape(left, top, texture, paint);
1451}
1452
1453void OpenGLRenderer::drawArc(float left, float top, float right, float bottom,
1454        float startAngle, float sweepAngle, bool useCenter, SkPaint* paint) {
1455    if (mSnapshot->isIgnored()) return;
1456
1457    if (fabs(sweepAngle) >= 360.0f) {
1458        drawOval(left, top, right, bottom, paint);
1459        return;
1460    }
1461
1462    glActiveTexture(gTextureUnits[0]);
1463    const PathTexture* texture = mCaches.arcShapeCache.getArc(right - left, bottom - top,
1464            startAngle, sweepAngle, useCenter, paint);
1465    drawShape(left, top, texture, paint);
1466}
1467
1468void OpenGLRenderer::drawRectAsShape(float left, float top, float right, float bottom,
1469        SkPaint* paint) {
1470    if (mSnapshot->isIgnored()) return;
1471
1472    glActiveTexture(gTextureUnits[0]);
1473    const PathTexture* texture = mCaches.rectShapeCache.getRect(right - left, bottom - top, paint);
1474    drawShape(left, top, texture, paint);
1475}
1476
1477void OpenGLRenderer::drawRect(float left, float top, float right, float bottom, SkPaint* p) {
1478    if (p->getStyle() != SkPaint::kFill_Style) {
1479        drawRectAsShape(left, top, right, bottom, p);
1480        return;
1481    }
1482
1483    if (quickReject(left, top, right, bottom)) {
1484        return;
1485    }
1486
1487    SkXfermode::Mode mode;
1488    if (!mCaches.extensions.hasFramebufferFetch()) {
1489        const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode);
1490        if (!isMode) {
1491            // Assume SRC_OVER
1492            mode = SkXfermode::kSrcOver_Mode;
1493        }
1494    } else {
1495        mode = getXfermode(p->getXfermode());
1496    }
1497
1498    int color = p->getColor();
1499    drawColorRect(left, top, right, bottom, color, mode);
1500}
1501
1502void OpenGLRenderer::drawText(const char* text, int bytesCount, int count,
1503        float x, float y, SkPaint* paint) {
1504    if (text == NULL || count == 0) {
1505        return;
1506    }
1507    if (mSnapshot->isIgnored()) return;
1508
1509    paint->setAntiAlias(true);
1510
1511    float length = -1.0f;
1512    switch (paint->getTextAlign()) {
1513        case SkPaint::kCenter_Align:
1514            length = paint->measureText(text, bytesCount);
1515            x -= length / 2.0f;
1516            break;
1517        case SkPaint::kRight_Align:
1518            length = paint->measureText(text, bytesCount);
1519            x -= length;
1520            break;
1521        default:
1522            break;
1523    }
1524
1525    // TODO: Handle paint->getTextScaleX()
1526    const float oldX = x;
1527    const float oldY = y;
1528    const bool pureTranslate = mSnapshot->transform->isPureTranslate();
1529    if (pureTranslate) {
1530        x = (int) floorf(x + mSnapshot->transform->getTranslateX() + 0.5f);
1531        y = (int) floorf(y + mSnapshot->transform->getTranslateY() + 0.5f);
1532    }
1533
1534    FontRenderer& fontRenderer = mCaches.fontRenderer.getFontRenderer(paint);
1535    fontRenderer.setFont(paint, SkTypeface::UniqueID(paint->getTypeface()),
1536            paint->getTextSize());
1537
1538    int alpha;
1539    SkXfermode::Mode mode;
1540    getAlphaAndMode(paint, &alpha, &mode);
1541
1542    if (mHasShadow) {
1543        mCaches.dropShadowCache.setFontRenderer(fontRenderer);
1544        const ShadowTexture* shadow = mCaches.dropShadowCache.get(paint, text, bytesCount,
1545                count, mShadowRadius);
1546        const AutoTexture autoCleanup(shadow);
1547
1548        const float sx = x - shadow->left + mShadowDx;
1549        const float sy = y - shadow->top + mShadowDy;
1550
1551        const int shadowAlpha = ((mShadowColor >> 24) & 0xFF);
1552
1553        glActiveTexture(gTextureUnits[0]);
1554        setupDraw();
1555        setupDrawWithTexture(true);
1556        setupDrawAlpha8Color(mShadowColor, shadowAlpha < 255 ? shadowAlpha : alpha);
1557        setupDrawBlending(true, mode);
1558        setupDrawProgram();
1559        setupDrawModelView(sx, sy, sx + shadow->width, sy + shadow->height, pureTranslate);
1560        setupDrawTexture(shadow->id);
1561        setupDrawPureColorUniforms();
1562        setupDrawMesh(NULL, (GLvoid*) gMeshTextureOffset);
1563
1564        glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
1565        finishDrawTexture();
1566    }
1567
1568    if (paint->getAlpha() == 0 && paint->getXfermode() == NULL) {
1569        return;
1570    }
1571
1572    // Pick the appropriate texture filtering
1573    bool linearFilter = mSnapshot->transform->changesBounds();
1574    if (pureTranslate && !linearFilter) {
1575        linearFilter = fabs(y - (int) y) > 0.0f || fabs(x - (int) x) > 0.0f;
1576    }
1577
1578    glActiveTexture(gTextureUnits[0]);
1579    setupDraw();
1580    setupDrawDirtyRegionsDisabled();
1581    setupDrawWithTexture(true);
1582    setupDrawAlpha8Color(paint->getColor(), alpha);
1583    setupDrawColorFilter();
1584    setupDrawShader();
1585    setupDrawBlending(true, mode);
1586    setupDrawProgram();
1587    setupDrawModelView(x, y, x, y, pureTranslate, true);
1588    setupDrawTexture(fontRenderer.getTexture(linearFilter));
1589    setupDrawPureColorUniforms();
1590    setupDrawColorFilterUniforms();
1591    setupDrawShaderUniforms(pureTranslate);
1592
1593    const Rect* clip = pureTranslate ? mSnapshot->clipRect : &mSnapshot->getLocalClip();
1594    Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
1595
1596#if RENDER_LAYERS_AS_REGIONS
1597    bool hasActiveLayer = hasLayer();
1598#else
1599    bool hasActiveLayer = false;
1600#endif
1601    mCaches.unbindMeshBuffer();
1602
1603    // Tell font renderer the locations of position and texture coord
1604    // attributes so it can bind its data properly
1605    int positionSlot = mCaches.currentProgram->position;
1606    fontRenderer.setAttributeBindingSlots(positionSlot, mTexCoordsSlot);
1607    if (fontRenderer.renderText(paint, clip, text, 0, bytesCount, count, x, y,
1608            hasActiveLayer ? &bounds : NULL)) {
1609#if RENDER_LAYERS_AS_REGIONS
1610        if (hasActiveLayer) {
1611            if (!pureTranslate) {
1612                mSnapshot->transform->mapRect(bounds);
1613            }
1614            dirtyLayerUnchecked(bounds, getRegion());
1615        }
1616#endif
1617    }
1618
1619    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
1620    glDisableVertexAttribArray(mCaches.currentProgram->getAttrib("texCoords"));
1621
1622    drawTextDecorations(text, bytesCount, length, oldX, oldY, paint);
1623}
1624
1625void OpenGLRenderer::drawPath(SkPath* path, SkPaint* paint) {
1626    if (mSnapshot->isIgnored()) return;
1627
1628    glActiveTexture(gTextureUnits[0]);
1629
1630    const PathTexture* texture = mCaches.pathCache.get(path, paint);
1631    if (!texture) return;
1632    const AutoTexture autoCleanup(texture);
1633
1634    const float x = texture->left - texture->offset;
1635    const float y = texture->top - texture->offset;
1636
1637    drawPathTexture(texture, x, y, paint);
1638}
1639
1640void OpenGLRenderer::drawLayer(Layer* layer, float x, float y, SkPaint* paint) {
1641    if (!layer || quickReject(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight())) {
1642        return;
1643    }
1644
1645    glActiveTexture(gTextureUnits[0]);
1646
1647    int alpha;
1648    SkXfermode::Mode mode;
1649    getAlphaAndMode(paint, &alpha, &mode);
1650
1651    layer->alpha = alpha;
1652    layer->mode = mode;
1653
1654#if RENDER_LAYERS_AS_REGIONS
1655    if (!layer->region.isEmpty()) {
1656        if (layer->region.isRect()) {
1657            const Rect r(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight());
1658            composeLayerRect(layer, r);
1659        } else if (layer->mesh) {
1660            const float a = alpha / 255.0f;
1661            const Rect& rect = layer->layer;
1662
1663            setupDraw();
1664            setupDrawWithTexture();
1665            setupDrawColor(a, a, a, a);
1666            setupDrawColorFilter();
1667            setupDrawBlending(layer->blend || layer->alpha < 255, layer->mode, false);
1668            setupDrawProgram();
1669            setupDrawPureColorUniforms();
1670            setupDrawColorFilterUniforms();
1671            setupDrawTexture(layer->texture);
1672            // TODO: The current layer, if any, will be dirtied with the bounding box
1673            //       of the layer we are drawing. Since the layer we are drawing has
1674            //       a mesh, we know the dirty region, we should use it instead
1675            setupDrawModelViewTranslate(rect.left, rect.top, rect.right, rect.bottom);
1676            setupDrawMesh(&layer->mesh[0].position[0], &layer->mesh[0].texture[0]);
1677
1678            glDrawElements(GL_TRIANGLES, layer->meshElementCount,
1679                    GL_UNSIGNED_SHORT, layer->meshIndices);
1680
1681            finishDrawTexture();
1682
1683#if DEBUG_LAYERS_AS_REGIONS
1684            drawRegionRects(layer->region);
1685#endif
1686        }
1687    }
1688#else
1689    const Rect r(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight());
1690    composeLayerRect(layer, r);
1691#endif
1692}
1693
1694///////////////////////////////////////////////////////////////////////////////
1695// Shaders
1696///////////////////////////////////////////////////////////////////////////////
1697
1698void OpenGLRenderer::resetShader() {
1699    mShader = NULL;
1700}
1701
1702void OpenGLRenderer::setupShader(SkiaShader* shader) {
1703    mShader = shader;
1704    if (mShader) {
1705        mShader->set(&mCaches.textureCache, &mCaches.gradientCache);
1706    }
1707}
1708
1709///////////////////////////////////////////////////////////////////////////////
1710// Color filters
1711///////////////////////////////////////////////////////////////////////////////
1712
1713void OpenGLRenderer::resetColorFilter() {
1714    mColorFilter = NULL;
1715}
1716
1717void OpenGLRenderer::setupColorFilter(SkiaColorFilter* filter) {
1718    mColorFilter = filter;
1719}
1720
1721///////////////////////////////////////////////////////////////////////////////
1722// Drop shadow
1723///////////////////////////////////////////////////////////////////////////////
1724
1725void OpenGLRenderer::resetShadow() {
1726    mHasShadow = false;
1727}
1728
1729void OpenGLRenderer::setupShadow(float radius, float dx, float dy, int color) {
1730    mHasShadow = true;
1731    mShadowRadius = radius;
1732    mShadowDx = dx;
1733    mShadowDy = dy;
1734    mShadowColor = color;
1735}
1736
1737///////////////////////////////////////////////////////////////////////////////
1738// Drawing implementation
1739///////////////////////////////////////////////////////////////////////////////
1740
1741void OpenGLRenderer::drawPathTexture(const PathTexture* texture,
1742        float x, float y, SkPaint* paint) {
1743    if (quickReject(x, y, x + texture->width, y + texture->height)) {
1744        return;
1745    }
1746
1747    int alpha;
1748    SkXfermode::Mode mode;
1749    getAlphaAndMode(paint, &alpha, &mode);
1750
1751    setupDraw();
1752    setupDrawWithTexture(true);
1753    setupDrawAlpha8Color(paint->getColor(), alpha);
1754    setupDrawColorFilter();
1755    setupDrawShader();
1756    setupDrawBlending(true, mode);
1757    setupDrawProgram();
1758    setupDrawModelView(x, y, x + texture->width, y + texture->height);
1759    setupDrawTexture(texture->id);
1760    setupDrawPureColorUniforms();
1761    setupDrawColorFilterUniforms();
1762    setupDrawShaderUniforms();
1763    setupDrawMesh(NULL, (GLvoid*) gMeshTextureOffset);
1764
1765    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
1766
1767    finishDrawTexture();
1768}
1769
1770// Same values used by Skia
1771#define kStdStrikeThru_Offset   (-6.0f / 21.0f)
1772#define kStdUnderline_Offset    (1.0f / 9.0f)
1773#define kStdUnderline_Thickness (1.0f / 18.0f)
1774
1775void OpenGLRenderer::drawTextDecorations(const char* text, int bytesCount, float length,
1776        float x, float y, SkPaint* paint) {
1777    // Handle underline and strike-through
1778    uint32_t flags = paint->getFlags();
1779    if (flags & (SkPaint::kUnderlineText_Flag | SkPaint::kStrikeThruText_Flag)) {
1780        float underlineWidth = length;
1781        // If length is > 0.0f, we already measured the text for the text alignment
1782        if (length <= 0.0f) {
1783            underlineWidth = paint->measureText(text, bytesCount);
1784        }
1785
1786        float offsetX = 0;
1787        switch (paint->getTextAlign()) {
1788            case SkPaint::kCenter_Align:
1789                offsetX = underlineWidth * 0.5f;
1790                break;
1791            case SkPaint::kRight_Align:
1792                offsetX = underlineWidth;
1793                break;
1794            default:
1795                break;
1796        }
1797
1798        if (underlineWidth > 0.0f) {
1799            const float textSize = paint->getTextSize();
1800            // TODO: Support stroke width < 1.0f when we have AA lines
1801            const float strokeWidth = fmax(textSize * kStdUnderline_Thickness, 1.0f);
1802
1803            const float left = x - offsetX;
1804            float top = 0.0f;
1805
1806            int linesCount = 0;
1807            if (flags & SkPaint::kUnderlineText_Flag) linesCount++;
1808            if (flags & SkPaint::kStrikeThruText_Flag) linesCount++;
1809
1810            const int pointsCount = 4 * linesCount;
1811            float points[pointsCount];
1812            int currentPoint = 0;
1813
1814            if (flags & SkPaint::kUnderlineText_Flag) {
1815                top = y + textSize * kStdUnderline_Offset;
1816                points[currentPoint++] = left;
1817                points[currentPoint++] = top;
1818                points[currentPoint++] = left + underlineWidth;
1819                points[currentPoint++] = top;
1820            }
1821
1822            if (flags & SkPaint::kStrikeThruText_Flag) {
1823                top = y + textSize * kStdStrikeThru_Offset;
1824                points[currentPoint++] = left;
1825                points[currentPoint++] = top;
1826                points[currentPoint++] = left + underlineWidth;
1827                points[currentPoint++] = top;
1828            }
1829
1830            SkPaint linesPaint(*paint);
1831            linesPaint.setStrokeWidth(strokeWidth);
1832
1833            drawLines(&points[0], pointsCount, &linesPaint);
1834        }
1835    }
1836}
1837
1838void OpenGLRenderer::drawColorRect(float left, float top, float right, float bottom,
1839        int color, SkXfermode::Mode mode, bool ignoreTransform) {
1840    // If a shader is set, preserve only the alpha
1841    if (mShader) {
1842        color |= 0x00ffffff;
1843    }
1844
1845    setupDraw();
1846    setupDrawColor(color);
1847    setupDrawShader();
1848    setupDrawColorFilter();
1849    setupDrawBlending(mode);
1850    setupDrawProgram();
1851    setupDrawModelView(left, top, right, bottom, ignoreTransform);
1852    setupDrawColorUniforms();
1853    setupDrawShaderUniforms(ignoreTransform);
1854    setupDrawColorFilterUniforms();
1855    setupDrawSimpleMesh();
1856
1857    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
1858}
1859
1860void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom,
1861        Texture* texture, SkPaint* paint) {
1862    int alpha;
1863    SkXfermode::Mode mode;
1864    getAlphaAndMode(paint, &alpha, &mode);
1865
1866    setTextureWrapModes(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
1867
1868    if (mSnapshot->transform->isPureTranslate()) {
1869        const float x = (int) floorf(left + mSnapshot->transform->getTranslateX() + 0.5f);
1870        const float y = (int) floorf(top + mSnapshot->transform->getTranslateY() + 0.5f);
1871
1872        drawTextureMesh(x, y, x + texture->width, y + texture->height, texture->id,
1873                alpha / 255.0f, mode, texture->blend, (GLvoid*) NULL,
1874                (GLvoid*) gMeshTextureOffset, GL_TRIANGLE_STRIP, gMeshCount, false, true);
1875    } else {
1876        drawTextureMesh(left, top, right, bottom, texture->id, alpha / 255.0f, mode,
1877                texture->blend, (GLvoid*) NULL, (GLvoid*) gMeshTextureOffset,
1878                GL_TRIANGLE_STRIP, gMeshCount);
1879    }
1880}
1881
1882void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom,
1883        GLuint texture, float alpha, SkXfermode::Mode mode, bool blend) {
1884    drawTextureMesh(left, top, right, bottom, texture, alpha, mode, blend,
1885            (GLvoid*) NULL, (GLvoid*) gMeshTextureOffset, GL_TRIANGLE_STRIP, gMeshCount);
1886}
1887
1888void OpenGLRenderer::drawTextureMesh(float left, float top, float right, float bottom,
1889        GLuint texture, float alpha, SkXfermode::Mode mode, bool blend,
1890        GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
1891        bool swapSrcDst, bool ignoreTransform, GLuint vbo, bool ignoreScale, bool dirty) {
1892
1893    setupDraw();
1894    setupDrawWithTexture();
1895    setupDrawColor(alpha, alpha, alpha, alpha);
1896    setupDrawColorFilter();
1897    setupDrawBlending(blend, mode, swapSrcDst);
1898    setupDrawProgram();
1899    if (!dirty) {
1900        setupDrawDirtyRegionsDisabled();
1901    }
1902    if (!ignoreScale) {
1903        setupDrawModelView(left, top, right, bottom, ignoreTransform);
1904    } else {
1905        setupDrawModelViewTranslate(left, top, right, bottom, ignoreTransform);
1906    }
1907    setupDrawPureColorUniforms();
1908    setupDrawColorFilterUniforms();
1909    setupDrawTexture(texture);
1910    setupDrawMesh(vertices, texCoords, vbo);
1911
1912    glDrawArrays(drawMode, 0, elementsCount);
1913
1914    finishDrawTexture();
1915}
1916
1917void OpenGLRenderer::chooseBlending(bool blend, SkXfermode::Mode mode,
1918        ProgramDescription& description, bool swapSrcDst) {
1919    blend = blend || mode != SkXfermode::kSrcOver_Mode;
1920    if (blend) {
1921        if (mode < SkXfermode::kPlus_Mode) {
1922            if (!mCaches.blend) {
1923                glEnable(GL_BLEND);
1924            }
1925
1926            GLenum sourceMode = swapSrcDst ? gBlendsSwap[mode].src : gBlends[mode].src;
1927            GLenum destMode = swapSrcDst ? gBlendsSwap[mode].dst : gBlends[mode].dst;
1928
1929            if (sourceMode != mCaches.lastSrcMode || destMode != mCaches.lastDstMode) {
1930                glBlendFunc(sourceMode, destMode);
1931                mCaches.lastSrcMode = sourceMode;
1932                mCaches.lastDstMode = destMode;
1933            }
1934        } else {
1935            // These blend modes are not supported by OpenGL directly and have
1936            // to be implemented using shaders. Since the shader will perform
1937            // the blending, turn blending off here
1938            if (mCaches.extensions.hasFramebufferFetch()) {
1939                description.framebufferMode = mode;
1940                description.swapSrcDst = swapSrcDst;
1941            }
1942
1943            if (mCaches.blend) {
1944                glDisable(GL_BLEND);
1945            }
1946            blend = false;
1947        }
1948    } else if (mCaches.blend) {
1949        glDisable(GL_BLEND);
1950    }
1951    mCaches.blend = blend;
1952}
1953
1954bool OpenGLRenderer::useProgram(Program* program) {
1955    if (!program->isInUse()) {
1956        if (mCaches.currentProgram != NULL) mCaches.currentProgram->remove();
1957        program->use();
1958        mCaches.currentProgram = program;
1959        return false;
1960    }
1961    return true;
1962}
1963
1964void OpenGLRenderer::resetDrawTextureTexCoords(float u1, float v1, float u2, float v2) {
1965    TextureVertex* v = &mMeshVertices[0];
1966    TextureVertex::setUV(v++, u1, v1);
1967    TextureVertex::setUV(v++, u2, v1);
1968    TextureVertex::setUV(v++, u1, v2);
1969    TextureVertex::setUV(v++, u2, v2);
1970}
1971
1972void OpenGLRenderer::getAlphaAndMode(SkPaint* paint, int* alpha, SkXfermode::Mode* mode) {
1973    if (paint) {
1974        if (!mCaches.extensions.hasFramebufferFetch()) {
1975            const bool isMode = SkXfermode::IsMode(paint->getXfermode(), mode);
1976            if (!isMode) {
1977                // Assume SRC_OVER
1978                *mode = SkXfermode::kSrcOver_Mode;
1979            }
1980        } else {
1981            *mode = getXfermode(paint->getXfermode());
1982        }
1983
1984        // Skia draws using the color's alpha channel if < 255
1985        // Otherwise, it uses the paint's alpha
1986        int color = paint->getColor();
1987        *alpha = (color >> 24) & 0xFF;
1988        if (*alpha == 255) {
1989            *alpha = paint->getAlpha();
1990        }
1991    } else {
1992        *mode = SkXfermode::kSrcOver_Mode;
1993        *alpha = 255;
1994    }
1995}
1996
1997SkXfermode::Mode OpenGLRenderer::getXfermode(SkXfermode* mode) {
1998    // In the future we should look at unifying the Porter-Duff modes and
1999    // SkXferModes so that we can use SkXfermode::IsMode(xfer, &mode).
2000    if (mode == NULL) {
2001        return SkXfermode::kSrcOver_Mode;
2002    }
2003    return mode->fMode;
2004}
2005
2006void OpenGLRenderer::setTextureWrapModes(Texture* texture, GLenum wrapS, GLenum wrapT) {
2007    bool bound = false;
2008    if (wrapS != texture->wrapS) {
2009        glBindTexture(GL_TEXTURE_2D, texture->id);
2010        bound = true;
2011        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrapS);
2012        texture->wrapS = wrapS;
2013    }
2014    if (wrapT != texture->wrapT) {
2015        if (!bound) {
2016            glBindTexture(GL_TEXTURE_2D, texture->id);
2017        }
2018        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrapT);
2019        texture->wrapT = wrapT;
2020    }
2021}
2022
2023}; // namespace uirenderer
2024}; // namespace android
2025