OpenGLRenderer.cpp revision f2fc460a9512500d9d5749fbaada88903d8e3b22 
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 <private/hwui/DrawGlInfo.h>
30
31#include <ui/Rect.h>
32
33#include "OpenGLRenderer.h"
34#include "DisplayListRenderer.h"
35#include "Vector.h"
36
37namespace android {
38namespace uirenderer {
39
40///////////////////////////////////////////////////////////////////////////////
41// Defines
42///////////////////////////////////////////////////////////////////////////////
43
44#define RAD_TO_DEG (180.0f / 3.14159265f)
45#define MIN_ANGLE 0.001f
46
47// TODO: This should be set in properties
48#define ALPHA_THRESHOLD (0x7f / PANEL_BIT_DEPTH)
49
50///////////////////////////////////////////////////////////////////////////////
51// Globals
52///////////////////////////////////////////////////////////////////////////////
53
54/**
55 * Structure mapping Skia xfermodes to OpenGL blending factors.
56 */
57struct Blender {
58    SkXfermode::Mode mode;
59    GLenum src;
60    GLenum dst;
61}; // struct Blender
62
63// In this array, the index of each Blender equals the value of the first
64// entry. For instance, gBlends[1] == gBlends[SkXfermode::kSrc_Mode]
65static const Blender gBlends[] = {
66    { SkXfermode::kClear_Mode,   GL_ZERO,                 GL_ONE_MINUS_SRC_ALPHA },
67    { SkXfermode::kSrc_Mode,     GL_ONE,                  GL_ZERO },
68    { SkXfermode::kDst_Mode,     GL_ZERO,                 GL_ONE },
69    { SkXfermode::kSrcOver_Mode, GL_ONE,                  GL_ONE_MINUS_SRC_ALPHA },
70    { SkXfermode::kDstOver_Mode, GL_ONE_MINUS_DST_ALPHA,  GL_ONE },
71    { SkXfermode::kSrcIn_Mode,   GL_DST_ALPHA,            GL_ZERO },
72    { SkXfermode::kDstIn_Mode,   GL_ZERO,                 GL_SRC_ALPHA },
73    { SkXfermode::kSrcOut_Mode,  GL_ONE_MINUS_DST_ALPHA,  GL_ZERO },
74    { SkXfermode::kDstOut_Mode,  GL_ZERO,                 GL_ONE_MINUS_SRC_ALPHA },
75    { SkXfermode::kSrcATop_Mode, GL_DST_ALPHA,            GL_ONE_MINUS_SRC_ALPHA },
76    { SkXfermode::kDstATop_Mode, GL_ONE_MINUS_DST_ALPHA,  GL_SRC_ALPHA },
77    { SkXfermode::kXor_Mode,     GL_ONE_MINUS_DST_ALPHA,  GL_ONE_MINUS_SRC_ALPHA }
78};
79
80// This array contains the swapped version of each SkXfermode. For instance
81// this array's SrcOver blending mode is actually DstOver. You can refer to
82// createLayer() for more information on the purpose of this array.
83static const Blender gBlendsSwap[] = {
84    { SkXfermode::kClear_Mode,   GL_ONE_MINUS_DST_ALPHA,  GL_ZERO },
85    { SkXfermode::kSrc_Mode,     GL_ZERO,                 GL_ONE },
86    { SkXfermode::kDst_Mode,     GL_ONE,                  GL_ZERO },
87    { SkXfermode::kSrcOver_Mode, GL_ONE_MINUS_DST_ALPHA,  GL_ONE },
88    { SkXfermode::kDstOver_Mode, GL_ONE,                  GL_ONE_MINUS_SRC_ALPHA },
89    { SkXfermode::kSrcIn_Mode,   GL_ZERO,                 GL_SRC_ALPHA },
90    { SkXfermode::kDstIn_Mode,   GL_DST_ALPHA,            GL_ZERO },
91    { SkXfermode::kSrcOut_Mode,  GL_ZERO,                 GL_ONE_MINUS_SRC_ALPHA },
92    { SkXfermode::kDstOut_Mode,  GL_ONE_MINUS_DST_ALPHA,  GL_ZERO },
93    { SkXfermode::kSrcATop_Mode, GL_ONE_MINUS_DST_ALPHA,  GL_SRC_ALPHA },
94    { SkXfermode::kDstATop_Mode, GL_DST_ALPHA,            GL_ONE_MINUS_SRC_ALPHA },
95    { SkXfermode::kXor_Mode,     GL_ONE_MINUS_DST_ALPHA,  GL_ONE_MINUS_SRC_ALPHA }
96};
97
98static const GLenum gTextureUnits[] = {
99    GL_TEXTURE0,
100    GL_TEXTURE1,
101    GL_TEXTURE2
102};
103
104///////////////////////////////////////////////////////////////////////////////
105// Constructors/destructor
106///////////////////////////////////////////////////////////////////////////////
107
108OpenGLRenderer::OpenGLRenderer(): mCaches(Caches::getInstance()) {
109    mShader = NULL;
110    mColorFilter = NULL;
111    mHasShadow = false;
112
113    memcpy(mMeshVertices, gMeshVertices, sizeof(gMeshVertices));
114
115    mFirstSnapshot = new Snapshot;
116}
117
118OpenGLRenderer::~OpenGLRenderer() {
119    // The context has already been destroyed at this point, do not call
120    // GL APIs. All GL state should be kept in Caches.h
121}
122
123///////////////////////////////////////////////////////////////////////////////
124// Setup
125///////////////////////////////////////////////////////////////////////////////
126
127void OpenGLRenderer::setViewport(int width, int height) {
128    glDisable(GL_DITHER);
129    glViewport(0, 0, width, height);
130    mOrthoMatrix.loadOrtho(0, width, height, 0, -1, 1);
131
132    mWidth = width;
133    mHeight = height;
134
135    mFirstSnapshot->height = height;
136    mFirstSnapshot->viewport.set(0, 0, width, height);
137
138    mDirtyClip = false;
139}
140
141void OpenGLRenderer::prepare(bool opaque) {
142    prepareDirty(0.0f, 0.0f, mWidth, mHeight, opaque);
143}
144
145void OpenGLRenderer::prepareDirty(float left, float top, float right, float bottom, bool opaque) {
146    mCaches.clearGarbage();
147
148    mSnapshot = new Snapshot(mFirstSnapshot,
149            SkCanvas::kMatrix_SaveFlag | SkCanvas::kClip_SaveFlag);
150    mSnapshot->fbo = getTargetFbo();
151
152    mSaveCount = 1;
153
154    glViewport(0, 0, mWidth, mHeight);
155
156    glEnable(GL_SCISSOR_TEST);
157    glScissor(left, mSnapshot->height - bottom, right - left, bottom - top);
158    mSnapshot->setClip(left, top, right, bottom);
159
160    if (!opaque) {
161        glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
162        glClear(GL_COLOR_BUFFER_BIT);
163    }
164}
165
166void OpenGLRenderer::finish() {
167#if DEBUG_OPENGL
168    GLenum status = GL_NO_ERROR;
169    while ((status = glGetError()) != GL_NO_ERROR) {
170        LOGD("GL error from OpenGLRenderer: 0x%x", status);
171        switch (status) {
172            case GL_OUT_OF_MEMORY:
173                LOGE("  OpenGLRenderer is out of memory!");
174                break;
175        }
176    }
177#endif
178#if DEBUG_MEMORY_USAGE
179    mCaches.dumpMemoryUsage();
180#else
181    if (mCaches.getDebugLevel() & kDebugMemory) {
182        mCaches.dumpMemoryUsage();
183    }
184#endif
185}
186
187void OpenGLRenderer::interrupt() {
188    if (mCaches.currentProgram) {
189        if (mCaches.currentProgram->isInUse()) {
190            mCaches.currentProgram->remove();
191            mCaches.currentProgram = NULL;
192        }
193    }
194    mCaches.unbindMeshBuffer();
195}
196
197void OpenGLRenderer::resume() {
198    glViewport(0, 0, mSnapshot->viewport.getWidth(), mSnapshot->viewport.getHeight());
199
200    glEnable(GL_SCISSOR_TEST);
201    dirtyClip();
202
203    glDisable(GL_DITHER);
204
205    glBindFramebuffer(GL_FRAMEBUFFER, getTargetFbo());
206    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
207
208    mCaches.blend = true;
209    glEnable(GL_BLEND);
210    glBlendFunc(mCaches.lastSrcMode, mCaches.lastDstMode);
211    glBlendEquation(GL_FUNC_ADD);
212}
213
214bool OpenGLRenderer::callDrawGLFunction(Functor *functor, Rect& dirty) {
215    interrupt();
216    if (mDirtyClip) {
217        setScissorFromClip();
218    }
219
220    Rect clip(*mSnapshot->clipRect);
221    clip.snapToPixelBoundaries();
222
223#if RENDER_LAYERS_AS_REGIONS
224    // Since we don't know what the functor will draw, let's dirty
225    // tne entire clip region
226    if (hasLayer()) {
227        dirtyLayerUnchecked(clip, getRegion());
228    }
229#endif
230
231    DrawGlInfo info;
232    info.clipLeft = clip.left;
233    info.clipTop = clip.top;
234    info.clipRight = clip.right;
235    info.clipBottom = clip.bottom;
236    info.isLayer = hasLayer();
237    getSnapshot()->transform->copyTo(&info.transform[0]);
238
239    status_t result = (*functor)(0, &info);
240
241    if (result != 0) {
242        Rect localDirty(info.dirtyLeft, info.dirtyTop, info.dirtyRight, info.dirtyBottom);
243        dirty.unionWith(localDirty);
244    }
245
246    resume();
247    return result != 0;
248}
249
250///////////////////////////////////////////////////////////////////////////////
251// State management
252///////////////////////////////////////////////////////////////////////////////
253
254int OpenGLRenderer::getSaveCount() const {
255    return mSaveCount;
256}
257
258int OpenGLRenderer::save(int flags) {
259    return saveSnapshot(flags);
260}
261
262void OpenGLRenderer::restore() {
263    if (mSaveCount > 1) {
264        restoreSnapshot();
265    }
266}
267
268void OpenGLRenderer::restoreToCount(int saveCount) {
269    if (saveCount < 1) saveCount = 1;
270
271    while (mSaveCount > saveCount) {
272        restoreSnapshot();
273    }
274}
275
276int OpenGLRenderer::saveSnapshot(int flags) {
277    mSnapshot = new Snapshot(mSnapshot, flags);
278    return mSaveCount++;
279}
280
281bool OpenGLRenderer::restoreSnapshot() {
282    bool restoreClip = mSnapshot->flags & Snapshot::kFlagClipSet;
283    bool restoreLayer = mSnapshot->flags & Snapshot::kFlagIsLayer;
284    bool restoreOrtho = mSnapshot->flags & Snapshot::kFlagDirtyOrtho;
285
286    sp<Snapshot> current = mSnapshot;
287    sp<Snapshot> previous = mSnapshot->previous;
288
289    if (restoreOrtho) {
290        Rect& r = previous->viewport;
291        glViewport(r.left, r.top, r.right, r.bottom);
292        mOrthoMatrix.load(current->orthoMatrix);
293    }
294
295    mSaveCount--;
296    mSnapshot = previous;
297
298    if (restoreClip) {
299        dirtyClip();
300    }
301
302    if (restoreLayer) {
303        composeLayer(current, previous);
304    }
305
306    return restoreClip;
307}
308
309///////////////////////////////////////////////////////////////////////////////
310// Layers
311///////////////////////////////////////////////////////////////////////////////
312
313int OpenGLRenderer::saveLayer(float left, float top, float right, float bottom,
314        SkPaint* p, int flags) {
315    const GLuint previousFbo = mSnapshot->fbo;
316    const int count = saveSnapshot(flags);
317
318    if (!mSnapshot->isIgnored()) {
319        int alpha = 255;
320        SkXfermode::Mode mode;
321
322        if (p) {
323            alpha = p->getAlpha();
324            if (!mCaches.extensions.hasFramebufferFetch()) {
325                const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode);
326                if (!isMode) {
327                    // Assume SRC_OVER
328                    mode = SkXfermode::kSrcOver_Mode;
329                }
330            } else {
331                mode = getXfermode(p->getXfermode());
332            }
333        } else {
334            mode = SkXfermode::kSrcOver_Mode;
335        }
336
337        createLayer(mSnapshot, left, top, right, bottom, alpha, mode, flags, previousFbo);
338    }
339
340    return count;
341}
342
343int OpenGLRenderer::saveLayerAlpha(float left, float top, float right, float bottom,
344        int alpha, int flags) {
345    if (alpha >= 255 - ALPHA_THRESHOLD) {
346        return saveLayer(left, top, right, bottom, NULL, flags);
347    } else {
348        SkPaint paint;
349        paint.setAlpha(alpha);
350        return saveLayer(left, top, right, bottom, &paint, flags);
351    }
352}
353
354/**
355 * Layers are viewed by Skia are slightly different than layers in image editing
356 * programs (for instance.) When a layer is created, previously created layers
357 * and the frame buffer still receive every drawing command. For instance, if a
358 * layer is created and a shape intersecting the bounds of the layers and the
359 * framebuffer is draw, the shape will be drawn on both (unless the layer was
360 * created with the SkCanvas::kClipToLayer_SaveFlag flag.)
361 *
362 * A way to implement layers is to create an FBO for each layer, backed by an RGBA
363 * texture. Unfortunately, this is inefficient as it requires every primitive to
364 * be drawn n + 1 times, where n is the number of active layers. In practice this
365 * means, for every primitive:
366 *   - Switch active frame buffer
367 *   - Change viewport, clip and projection matrix
368 *   - Issue the drawing
369 *
370 * Switching rendering target n + 1 times per drawn primitive is extremely costly.
371 * To avoid this, layers are implemented in a different way here, at least in the
372 * general case. FBOs are used, as an optimization, when the "clip to layer" flag
373 * is set. When this flag is set we can redirect all drawing operations into a
374 * single FBO.
375 *
376 * This implementation relies on the frame buffer being at least RGBA 8888. When
377 * a layer is created, only a texture is created, not an FBO. The content of the
378 * frame buffer contained within the layer's bounds is copied into this texture
379 * using glCopyTexImage2D(). The layer's region is then cleared(1) in the frame
380 * buffer and drawing continues as normal. This technique therefore treats the
381 * frame buffer as a scratch buffer for the layers.
382 *
383 * To compose the layers back onto the frame buffer, each layer texture
384 * (containing the original frame buffer data) is drawn as a simple quad over
385 * the frame buffer. The trick is that the quad is set as the composition
386 * destination in the blending equation, and the frame buffer becomes the source
387 * of the composition.
388 *
389 * Drawing layers with an alpha value requires an extra step before composition.
390 * An empty quad is drawn over the layer's region in the frame buffer. This quad
391 * is drawn with the rgba color (0,0,0,alpha). The alpha value offered by the
392 * quad is used to multiply the colors in the frame buffer. This is achieved by
393 * changing the GL blend functions for the GL_FUNC_ADD blend equation to
394 * GL_ZERO, GL_SRC_ALPHA.
395 *
396 * Because glCopyTexImage2D() can be slow, an alternative implementation might
397 * be use to draw a single clipped layer. The implementation described above
398 * is correct in every case.
399 *
400 * (1) The frame buffer is actually not cleared right away. To allow the GPU
401 *     to potentially optimize series of calls to glCopyTexImage2D, the frame
402 *     buffer is left untouched until the first drawing operation. Only when
403 *     something actually gets drawn are the layers regions cleared.
404 */
405bool OpenGLRenderer::createLayer(sp<Snapshot> snapshot, float left, float top,
406        float right, float bottom, int alpha, SkXfermode::Mode mode,
407        int flags, GLuint previousFbo) {
408    LAYER_LOGD("Requesting layer %.2fx%.2f", right - left, bottom - top);
409    LAYER_LOGD("Layer cache size = %d", mCaches.layerCache.getSize());
410
411    const bool fboLayer = flags & SkCanvas::kClipToLayer_SaveFlag;
412
413    // Window coordinates of the layer
414    Rect bounds(left, top, right, bottom);
415    if (!fboLayer) {
416        mSnapshot->transform->mapRect(bounds);
417
418        // Layers only make sense if they are in the framebuffer's bounds
419        if (bounds.intersect(*snapshot->clipRect)) {
420            // We cannot work with sub-pixels in this case
421            bounds.snapToPixelBoundaries();
422
423            // When the layer is not an FBO, we may use glCopyTexImage so we
424            // need to make sure the layer does not extend outside the bounds
425            // of the framebuffer
426            if (!bounds.intersect(snapshot->previous->viewport)) {
427                bounds.setEmpty();
428            }
429        } else {
430            bounds.setEmpty();
431        }
432    }
433
434    if (bounds.isEmpty() || bounds.getWidth() > mCaches.maxTextureSize ||
435            bounds.getHeight() > mCaches.maxTextureSize) {
436        snapshot->empty = fboLayer;
437    } else {
438        snapshot->invisible = snapshot->invisible || (alpha <= ALPHA_THRESHOLD && fboLayer);
439    }
440
441    // Bail out if we won't draw in this snapshot
442    if (snapshot->invisible || snapshot->empty) {
443        return false;
444    }
445
446    glActiveTexture(gTextureUnits[0]);
447    Layer* layer = mCaches.layerCache.get(bounds.getWidth(), bounds.getHeight());
448    if (!layer) {
449        return false;
450    }
451
452    layer->setAlpha(alpha, mode);
453    layer->layer.set(bounds);
454    layer->texCoords.set(0.0f, bounds.getHeight() / float(layer->getHeight()),
455            bounds.getWidth() / float(layer->getWidth()), 0.0f);
456    layer->setColorFilter(mColorFilter);
457
458    // Save the layer in the snapshot
459    snapshot->flags |= Snapshot::kFlagIsLayer;
460    snapshot->layer = layer;
461
462    if (fboLayer) {
463        return createFboLayer(layer, bounds, snapshot, previousFbo);
464    } else {
465        // Copy the framebuffer into the layer
466        layer->bindTexture();
467        if (!bounds.isEmpty()) {
468            if (layer->isEmpty()) {
469                glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA,
470                        bounds.left, snapshot->height - bounds.bottom,
471                        layer->getWidth(), layer->getHeight(), 0);
472                layer->setEmpty(false);
473            } else {
474                glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, bounds.left,
475                        snapshot->height - bounds.bottom, bounds.getWidth(), bounds.getHeight());
476            }
477
478            // Enqueue the buffer coordinates to clear the corresponding region later
479            mLayers.push(new Rect(bounds));
480        }
481    }
482
483    return true;
484}
485
486bool OpenGLRenderer::createFboLayer(Layer* layer, Rect& bounds, sp<Snapshot> snapshot,
487        GLuint previousFbo) {
488    layer->setFbo(mCaches.fboCache.get());
489
490#if RENDER_LAYERS_AS_REGIONS
491    snapshot->region = &snapshot->layer->region;
492    snapshot->flags |= Snapshot::kFlagFboTarget;
493#endif
494
495    Rect clip(bounds);
496    snapshot->transform->mapRect(clip);
497    clip.intersect(*snapshot->clipRect);
498    clip.snapToPixelBoundaries();
499    clip.intersect(snapshot->previous->viewport);
500
501    mat4 inverse;
502    inverse.loadInverse(*mSnapshot->transform);
503
504    inverse.mapRect(clip);
505    clip.snapToPixelBoundaries();
506    clip.intersect(bounds);
507    clip.translate(-bounds.left, -bounds.top);
508
509    snapshot->flags |= Snapshot::kFlagIsFboLayer;
510    snapshot->fbo = layer->getFbo();
511    snapshot->resetTransform(-bounds.left, -bounds.top, 0.0f);
512    snapshot->resetClip(clip.left, clip.top, clip.right, clip.bottom);
513    snapshot->viewport.set(0.0f, 0.0f, bounds.getWidth(), bounds.getHeight());
514    snapshot->height = bounds.getHeight();
515    snapshot->flags |= Snapshot::kFlagDirtyOrtho;
516    snapshot->orthoMatrix.load(mOrthoMatrix);
517
518    // Bind texture to FBO
519    glBindFramebuffer(GL_FRAMEBUFFER, layer->getFbo());
520    layer->bindTexture();
521
522    // Initialize the texture if needed
523    if (layer->isEmpty()) {
524        layer->allocateTexture(GL_RGBA, GL_UNSIGNED_BYTE);
525        layer->setEmpty(false);
526    }
527
528    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
529            layer->getTexture(), 0);
530
531#if DEBUG_LAYERS_AS_REGIONS
532    GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
533    if (status != GL_FRAMEBUFFER_COMPLETE) {
534        LOGE("Framebuffer incomplete (GL error code 0x%x)", status);
535
536        glBindFramebuffer(GL_FRAMEBUFFER, previousFbo);
537        layer->deleteTexture();
538        mCaches.fboCache.put(layer->getFbo());
539
540        delete layer;
541
542        return false;
543    }
544#endif
545
546    // Clear the FBO, expand the clear region by 1 to get nice bilinear filtering
547    glScissor(clip.left - 1.0f, bounds.getHeight() - clip.bottom - 1.0f,
548            clip.getWidth() + 2.0f, clip.getHeight() + 2.0f);
549    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
550    glClear(GL_COLOR_BUFFER_BIT);
551
552    dirtyClip();
553
554    // Change the ortho projection
555    glViewport(0, 0, bounds.getWidth(), bounds.getHeight());
556    mOrthoMatrix.loadOrtho(0.0f, bounds.getWidth(), bounds.getHeight(), 0.0f, -1.0f, 1.0f);
557
558    return true;
559}
560
561/**
562 * Read the documentation of createLayer() before doing anything in this method.
563 */
564void OpenGLRenderer::composeLayer(sp<Snapshot> current, sp<Snapshot> previous) {
565    if (!current->layer) {
566        LOGE("Attempting to compose a layer that does not exist");
567        return;
568    }
569
570    const bool fboLayer = current->flags & Snapshot::kFlagIsFboLayer;
571
572    if (fboLayer) {
573        // Unbind current FBO and restore previous one
574        glBindFramebuffer(GL_FRAMEBUFFER, previous->fbo);
575    }
576
577    Layer* layer = current->layer;
578    const Rect& rect = layer->layer;
579
580    if (!fboLayer && layer->getAlpha() < 255) {
581        drawColorRect(rect.left, rect.top, rect.right, rect.bottom,
582                layer->getAlpha() << 24, SkXfermode::kDstIn_Mode, true);
583        // Required below, composeLayerRect() will divide by 255
584        layer->setAlpha(255);
585    }
586
587    mCaches.unbindMeshBuffer();
588
589    glActiveTexture(gTextureUnits[0]);
590
591    // When the layer is stored in an FBO, we can save a bit of fillrate by
592    // drawing only the dirty region
593    if (fboLayer) {
594        dirtyLayer(rect.left, rect.top, rect.right, rect.bottom, *previous->transform);
595        if (layer->getColorFilter()) {
596            setupColorFilter(layer->getColorFilter());
597        }
598        composeLayerRegion(layer, rect);
599        if (layer->getColorFilter()) {
600            resetColorFilter();
601        }
602    } else if (!rect.isEmpty()) {
603        dirtyLayer(rect.left, rect.top, rect.right, rect.bottom);
604        composeLayerRect(layer, rect, true);
605    }
606
607    if (fboLayer) {
608        // Detach the texture from the FBO
609        glBindFramebuffer(GL_FRAMEBUFFER, current->fbo);
610        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 0, 0);
611        glBindFramebuffer(GL_FRAMEBUFFER, previous->fbo);
612
613        // Put the FBO name back in the cache, if it doesn't fit, it will be destroyed
614        mCaches.fboCache.put(current->fbo);
615    }
616
617    dirtyClip();
618
619    // Failing to add the layer to the cache should happen only if the layer is too large
620    if (!mCaches.layerCache.put(layer)) {
621        LAYER_LOGD("Deleting layer");
622        layer->deleteTexture();
623        delete layer;
624    }
625}
626
627void OpenGLRenderer::drawTextureLayer(Layer* layer, const Rect& rect) {
628    float alpha = layer->getAlpha() / 255.0f;
629
630    setupDraw();
631    if (layer->getRenderTarget() == GL_TEXTURE_2D) {
632        setupDrawWithTexture();
633    } else {
634        setupDrawWithExternalTexture();
635    }
636    setupDrawTextureTransform();
637    setupDrawColor(alpha, alpha, alpha, alpha);
638    setupDrawColorFilter();
639    setupDrawBlending(layer->isBlend() || alpha < 1.0f, layer->getMode());
640    setupDrawProgram();
641    setupDrawPureColorUniforms();
642    setupDrawColorFilterUniforms();
643    if (layer->getRenderTarget() == GL_TEXTURE_2D) {
644        setupDrawTexture(layer->getTexture());
645    } else {
646        setupDrawExternalTexture(layer->getTexture());
647    }
648    if (mSnapshot->transform->isPureTranslate() &&
649            layer->getWidth() == (uint32_t) rect.getWidth() &&
650            layer->getHeight() == (uint32_t) rect.getHeight()) {
651        const float x = (int) floorf(rect.left + mSnapshot->transform->getTranslateX() + 0.5f);
652        const float y = (int) floorf(rect.top + mSnapshot->transform->getTranslateY() + 0.5f);
653
654        layer->setFilter(GL_NEAREST, GL_NEAREST);
655        setupDrawModelView(x, y, x + rect.getWidth(), y + rect.getHeight(), true);
656    } else {
657        layer->setFilter(GL_LINEAR, GL_LINEAR);
658        setupDrawModelView(rect.left, rect.top, rect.right, rect.bottom);
659    }
660    setupDrawTextureTransformUniforms(layer->getTexTransform());
661    setupDrawMesh(&mMeshVertices[0].position[0], &mMeshVertices[0].texture[0]);
662
663    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
664
665    finishDrawTexture();
666}
667
668void OpenGLRenderer::composeLayerRect(Layer* layer, const Rect& rect, bool swap) {
669    if (!layer->isTextureLayer()) {
670        const Rect& texCoords = layer->texCoords;
671        resetDrawTextureTexCoords(texCoords.left, texCoords.top,
672                texCoords.right, texCoords.bottom);
673
674        float x = rect.left;
675        float y = rect.top;
676        bool simpleTransform = mSnapshot->transform->isPureTranslate() &&
677                layer->getWidth() == (uint32_t) rect.getWidth() &&
678                layer->getHeight() == (uint32_t) rect.getHeight();
679
680        if (simpleTransform) {
681            // When we're swapping, the layer is already in screen coordinates
682            if (!swap) {
683                x = (int) floorf(rect.left + mSnapshot->transform->getTranslateX() + 0.5f);
684                y = (int) floorf(rect.top + mSnapshot->transform->getTranslateY() + 0.5f);
685            }
686
687            layer->setFilter(GL_NEAREST, GL_NEAREST, true);
688        } else {
689            layer->setFilter(GL_LINEAR, GL_LINEAR, true);
690        }
691
692        drawTextureMesh(x, y, x + rect.getWidth(), y + rect.getHeight(),
693                layer->getTexture(), layer->getAlpha() / 255.0f,
694                layer->getMode(), layer->isBlend(),
695                &mMeshVertices[0].position[0], &mMeshVertices[0].texture[0],
696                GL_TRIANGLE_STRIP, gMeshCount, swap, swap || simpleTransform);
697
698        resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
699    } else {
700        resetDrawTextureTexCoords(0.0f, 1.0f, 1.0f, 0.0f);
701        drawTextureLayer(layer, rect);
702        resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
703    }
704}
705
706void OpenGLRenderer::composeLayerRegion(Layer* layer, const Rect& rect) {
707#if RENDER_LAYERS_AS_REGIONS
708    if (layer->region.isRect()) {
709        layer->setRegionAsRect();
710
711        composeLayerRect(layer, layer->regionRect);
712
713        layer->region.clear();
714        return;
715    }
716
717    if (!layer->region.isEmpty()) {
718        size_t count;
719        const android::Rect* rects = layer->region.getArray(&count);
720
721        const float alpha = layer->getAlpha() / 255.0f;
722        const float texX = 1.0f / float(layer->getWidth());
723        const float texY = 1.0f / float(layer->getHeight());
724        const float height = rect.getHeight();
725
726        TextureVertex* mesh = mCaches.getRegionMesh();
727        GLsizei numQuads = 0;
728
729        setupDraw();
730        setupDrawWithTexture();
731        setupDrawColor(alpha, alpha, alpha, alpha);
732        setupDrawColorFilter();
733        setupDrawBlending(layer->isBlend() || alpha < 1.0f, layer->getMode(), false);
734        setupDrawProgram();
735        setupDrawDirtyRegionsDisabled();
736        setupDrawPureColorUniforms();
737        setupDrawColorFilterUniforms();
738        setupDrawTexture(layer->getTexture());
739        if (mSnapshot->transform->isPureTranslate()) {
740            const float x = (int) floorf(rect.left + mSnapshot->transform->getTranslateX() + 0.5f);
741            const float y = (int) floorf(rect.top + mSnapshot->transform->getTranslateY() + 0.5f);
742
743            layer->setFilter(GL_NEAREST, GL_NEAREST);
744            setupDrawModelViewTranslate(x, y, x + rect.getWidth(), y + rect.getHeight(), true);
745        } else {
746            layer->setFilter(GL_LINEAR, GL_LINEAR);
747            setupDrawModelViewTranslate(rect.left, rect.top, rect.right, rect.bottom);
748        }
749        setupDrawMesh(&mesh[0].position[0], &mesh[0].texture[0]);
750
751        for (size_t i = 0; i < count; i++) {
752            const android::Rect* r = &rects[i];
753
754            const float u1 = r->left * texX;
755            const float v1 = (height - r->top) * texY;
756            const float u2 = r->right * texX;
757            const float v2 = (height - r->bottom) * texY;
758
759            // TODO: Reject quads outside of the clip
760            TextureVertex::set(mesh++, r->left, r->top, u1, v1);
761            TextureVertex::set(mesh++, r->right, r->top, u2, v1);
762            TextureVertex::set(mesh++, r->left, r->bottom, u1, v2);
763            TextureVertex::set(mesh++, r->right, r->bottom, u2, v2);
764
765            numQuads++;
766
767            if (numQuads >= REGION_MESH_QUAD_COUNT) {
768                glDrawElements(GL_TRIANGLES, numQuads * 6, GL_UNSIGNED_SHORT, NULL);
769                numQuads = 0;
770                mesh = mCaches.getRegionMesh();
771            }
772        }
773
774        if (numQuads > 0) {
775            glDrawElements(GL_TRIANGLES, numQuads * 6, GL_UNSIGNED_SHORT, NULL);
776        }
777
778        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
779        finishDrawTexture();
780
781#if DEBUG_LAYERS_AS_REGIONS
782        drawRegionRects(layer->region);
783#endif
784
785        layer->region.clear();
786    }
787#else
788    composeLayerRect(layer, rect);
789#endif
790}
791
792void OpenGLRenderer::drawRegionRects(const Region& region) {
793#if DEBUG_LAYERS_AS_REGIONS
794    size_t count;
795    const android::Rect* rects = region.getArray(&count);
796
797    uint32_t colors[] = {
798            0x7fff0000, 0x7f00ff00,
799            0x7f0000ff, 0x7fff00ff,
800    };
801
802    int offset = 0;
803    int32_t top = rects[0].top;
804
805    for (size_t i = 0; i < count; i++) {
806        if (top != rects[i].top) {
807            offset ^= 0x2;
808            top = rects[i].top;
809        }
810
811        Rect r(rects[i].left, rects[i].top, rects[i].right, rects[i].bottom);
812        drawColorRect(r.left, r.top, r.right, r.bottom, colors[offset + (i & 0x1)],
813                SkXfermode::kSrcOver_Mode);
814    }
815#endif
816}
817
818void OpenGLRenderer::dirtyLayer(const float left, const float top,
819        const float right, const float bottom, const mat4 transform) {
820#if RENDER_LAYERS_AS_REGIONS
821    if (hasLayer()) {
822        Rect bounds(left, top, right, bottom);
823        transform.mapRect(bounds);
824        dirtyLayerUnchecked(bounds, getRegion());
825    }
826#endif
827}
828
829void OpenGLRenderer::dirtyLayer(const float left, const float top,
830        const float right, const float bottom) {
831#if RENDER_LAYERS_AS_REGIONS
832    if (hasLayer()) {
833        Rect bounds(left, top, right, bottom);
834        dirtyLayerUnchecked(bounds, getRegion());
835    }
836#endif
837}
838
839void OpenGLRenderer::dirtyLayerUnchecked(Rect& bounds, Region* region) {
840#if RENDER_LAYERS_AS_REGIONS
841    if (bounds.intersect(*mSnapshot->clipRect)) {
842        bounds.snapToPixelBoundaries();
843        android::Rect dirty(bounds.left, bounds.top, bounds.right, bounds.bottom);
844        if (!dirty.isEmpty()) {
845            region->orSelf(dirty);
846        }
847    }
848#endif
849}
850
851void OpenGLRenderer::clearLayerRegions() {
852    const size_t count = mLayers.size();
853    if (count == 0) return;
854
855    if (!mSnapshot->isIgnored()) {
856        // Doing several glScissor/glClear here can negatively impact
857        // GPUs with a tiler architecture, instead we draw quads with
858        // the Clear blending mode
859
860        // The list contains bounds that have already been clipped
861        // against their initial clip rect, and the current clip
862        // is likely different so we need to disable clipping here
863        glDisable(GL_SCISSOR_TEST);
864
865        Vertex mesh[count * 6];
866        Vertex* vertex = mesh;
867
868        for (uint32_t i = 0; i < count; i++) {
869            Rect* bounds = mLayers.itemAt(i);
870
871            Vertex::set(vertex++, bounds->left, bounds->bottom);
872            Vertex::set(vertex++, bounds->left, bounds->top);
873            Vertex::set(vertex++, bounds->right, bounds->top);
874            Vertex::set(vertex++, bounds->left, bounds->bottom);
875            Vertex::set(vertex++, bounds->right, bounds->top);
876            Vertex::set(vertex++, bounds->right, bounds->bottom);
877
878            delete bounds;
879        }
880
881        setupDraw(false);
882        setupDrawColor(0.0f, 0.0f, 0.0f, 1.0f);
883        setupDrawBlending(true, SkXfermode::kClear_Mode);
884        setupDrawProgram();
885        setupDrawPureColorUniforms();
886        setupDrawModelViewTranslate(0.0f, 0.0f, 0.0f, 0.0f, true);
887
888        mCaches.unbindMeshBuffer();
889        glVertexAttribPointer(mCaches.currentProgram->position, 2, GL_FLOAT, GL_FALSE,
890                gVertexStride, &mesh[0].position[0]);
891        glDrawArrays(GL_TRIANGLES, 0, count * 6);
892
893        glEnable(GL_SCISSOR_TEST);
894    } else {
895        for (uint32_t i = 0; i < count; i++) {
896            delete mLayers.itemAt(i);
897        }
898    }
899
900    mLayers.clear();
901}
902
903///////////////////////////////////////////////////////////////////////////////
904// Transforms
905///////////////////////////////////////////////////////////////////////////////
906
907void OpenGLRenderer::translate(float dx, float dy) {
908    mSnapshot->transform->translate(dx, dy, 0.0f);
909}
910
911void OpenGLRenderer::rotate(float degrees) {
912    mSnapshot->transform->rotate(degrees, 0.0f, 0.0f, 1.0f);
913}
914
915void OpenGLRenderer::scale(float sx, float sy) {
916    mSnapshot->transform->scale(sx, sy, 1.0f);
917}
918
919void OpenGLRenderer::skew(float sx, float sy) {
920    mSnapshot->transform->skew(sx, sy);
921}
922
923void OpenGLRenderer::setMatrix(SkMatrix* matrix) {
924    mSnapshot->transform->load(*matrix);
925}
926
927const float* OpenGLRenderer::getMatrix() const {
928    if (mSnapshot->fbo != 0) {
929        return &mSnapshot->transform->data[0];
930    }
931    return &mIdentity.data[0];
932}
933
934void OpenGLRenderer::getMatrix(SkMatrix* matrix) {
935    mSnapshot->transform->copyTo(*matrix);
936}
937
938void OpenGLRenderer::concatMatrix(SkMatrix* matrix) {
939    SkMatrix transform;
940    mSnapshot->transform->copyTo(transform);
941    transform.preConcat(*matrix);
942    mSnapshot->transform->load(transform);
943}
944
945///////////////////////////////////////////////////////////////////////////////
946// Clipping
947///////////////////////////////////////////////////////////////////////////////
948
949void OpenGLRenderer::setScissorFromClip() {
950    Rect clip(*mSnapshot->clipRect);
951    clip.snapToPixelBoundaries();
952    glScissor(clip.left, mSnapshot->height - clip.bottom, clip.getWidth(), clip.getHeight());
953    mDirtyClip = false;
954}
955
956const Rect& OpenGLRenderer::getClipBounds() {
957    return mSnapshot->getLocalClip();
958}
959
960bool OpenGLRenderer::quickReject(float left, float top, float right, float bottom) {
961    if (mSnapshot->isIgnored()) {
962        return true;
963    }
964
965    Rect r(left, top, right, bottom);
966    mSnapshot->transform->mapRect(r);
967    r.snapToPixelBoundaries();
968
969    Rect clipRect(*mSnapshot->clipRect);
970    clipRect.snapToPixelBoundaries();
971
972    return !clipRect.intersects(r);
973}
974
975bool OpenGLRenderer::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {
976    bool clipped = mSnapshot->clip(left, top, right, bottom, op);
977    if (clipped) {
978        dirtyClip();
979    }
980    return !mSnapshot->clipRect->isEmpty();
981}
982
983///////////////////////////////////////////////////////////////////////////////
984// Drawing commands
985///////////////////////////////////////////////////////////////////////////////
986
987void OpenGLRenderer::setupDraw(bool clear) {
988    if (clear) clearLayerRegions();
989    if (mDirtyClip) {
990        setScissorFromClip();
991    }
992    mDescription.reset();
993    mSetShaderColor = false;
994    mColorSet = false;
995    mColorA = mColorR = mColorG = mColorB = 0.0f;
996    mTextureUnit = 0;
997    mTrackDirtyRegions = true;
998    mTexCoordsSlot = -1;
999}
1000
1001void OpenGLRenderer::setupDrawWithTexture(bool isAlpha8) {
1002    mDescription.hasTexture = true;
1003    mDescription.hasAlpha8Texture = isAlpha8;
1004}
1005
1006void OpenGLRenderer::setupDrawWithExternalTexture() {
1007    mDescription.hasExternalTexture = true;
1008}
1009
1010void OpenGLRenderer::setupDrawAALine() {
1011    mDescription.isAA = true;
1012}
1013
1014void OpenGLRenderer::setupDrawPoint(float pointSize) {
1015    mDescription.isPoint = true;
1016    mDescription.pointSize = pointSize;
1017}
1018
1019void OpenGLRenderer::setupDrawColor(int color) {
1020    setupDrawColor(color, (color >> 24) & 0xFF);
1021}
1022
1023void OpenGLRenderer::setupDrawColor(int color, int alpha) {
1024    mColorA = alpha / 255.0f;
1025    // Second divide of a by 255 is an optimization, allowing us to simply multiply
1026    // the rgb values by a instead of also dividing by 255
1027    const float a = mColorA / 255.0f;
1028    mColorR = a * ((color >> 16) & 0xFF);
1029    mColorG = a * ((color >>  8) & 0xFF);
1030    mColorB = a * ((color      ) & 0xFF);
1031    mColorSet = true;
1032    mSetShaderColor = mDescription.setColor(mColorR, mColorG, mColorB, mColorA);
1033}
1034
1035void OpenGLRenderer::setupDrawAlpha8Color(int color, int alpha) {
1036    mColorA = alpha / 255.0f;
1037    // Double-divide of a by 255 is an optimization, allowing us to simply multiply
1038    // the rgb values by a instead of also dividing by 255
1039    const float a = mColorA / 255.0f;
1040    mColorR = a * ((color >> 16) & 0xFF);
1041    mColorG = a * ((color >>  8) & 0xFF);
1042    mColorB = a * ((color      ) & 0xFF);
1043    mColorSet = true;
1044    mSetShaderColor = mDescription.setAlpha8Color(mColorR, mColorG, mColorB, mColorA);
1045}
1046
1047void OpenGLRenderer::setupDrawColor(float r, float g, float b, float a) {
1048    mColorA = a;
1049    mColorR = r;
1050    mColorG = g;
1051    mColorB = b;
1052    mColorSet = true;
1053    mSetShaderColor = mDescription.setColor(r, g, b, a);
1054}
1055
1056void OpenGLRenderer::setupDrawAlpha8Color(float r, float g, float b, float a) {
1057    mColorA = a;
1058    mColorR = r;
1059    mColorG = g;
1060    mColorB = b;
1061    mColorSet = true;
1062    mSetShaderColor = mDescription.setAlpha8Color(r, g, b, a);
1063}
1064
1065void OpenGLRenderer::setupDrawShader() {
1066    if (mShader) {
1067        mShader->describe(mDescription, mCaches.extensions);
1068    }
1069}
1070
1071void OpenGLRenderer::setupDrawColorFilter() {
1072    if (mColorFilter) {
1073        mColorFilter->describe(mDescription, mCaches.extensions);
1074    }
1075}
1076
1077void OpenGLRenderer::accountForClear(SkXfermode::Mode mode) {
1078    if (mColorSet && mode == SkXfermode::kClear_Mode) {
1079        mColorA = 1.0f;
1080        mColorR = mColorG = mColorB = 0.0f;
1081        mSetShaderColor = mDescription.modulate = true;
1082    }
1083}
1084
1085void OpenGLRenderer::setupDrawBlending(SkXfermode::Mode mode, bool swapSrcDst) {
1086    // When the blending mode is kClear_Mode, we need to use a modulate color
1087    // argb=1,0,0,0
1088    accountForClear(mode);
1089    chooseBlending((mColorSet && mColorA < 1.0f) || (mShader && mShader->blend()), mode,
1090            mDescription, swapSrcDst);
1091}
1092
1093void OpenGLRenderer::setupDrawBlending(bool blend, SkXfermode::Mode mode, bool swapSrcDst) {
1094    // When the blending mode is kClear_Mode, we need to use a modulate color
1095    // argb=1,0,0,0
1096    accountForClear(mode);
1097    chooseBlending(blend || (mColorSet && mColorA < 1.0f) || (mShader && mShader->blend()), mode,
1098            mDescription, swapSrcDst);
1099}
1100
1101void OpenGLRenderer::setupDrawProgram() {
1102    useProgram(mCaches.programCache.get(mDescription));
1103}
1104
1105void OpenGLRenderer::setupDrawDirtyRegionsDisabled() {
1106    mTrackDirtyRegions = false;
1107}
1108
1109void OpenGLRenderer::setupDrawModelViewTranslate(float left, float top, float right, float bottom,
1110        bool ignoreTransform) {
1111    mModelView.loadTranslate(left, top, 0.0f);
1112    if (!ignoreTransform) {
1113        mCaches.currentProgram->set(mOrthoMatrix, mModelView, *mSnapshot->transform);
1114        if (mTrackDirtyRegions) dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
1115    } else {
1116        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mIdentity);
1117        if (mTrackDirtyRegions) dirtyLayer(left, top, right, bottom);
1118    }
1119}
1120
1121void OpenGLRenderer::setupDrawModelViewIdentity(bool offset) {
1122    mCaches.currentProgram->set(mOrthoMatrix, mIdentity, *mSnapshot->transform, offset);
1123}
1124
1125void OpenGLRenderer::setupDrawModelView(float left, float top, float right, float bottom,
1126        bool ignoreTransform, bool ignoreModelView) {
1127    if (!ignoreModelView) {
1128        mModelView.loadTranslate(left, top, 0.0f);
1129        mModelView.scale(right - left, bottom - top, 1.0f);
1130    } else {
1131        mModelView.loadIdentity();
1132    }
1133    bool dirty = right - left > 0.0f && bottom - top > 0.0f;
1134    if (!ignoreTransform) {
1135        mCaches.currentProgram->set(mOrthoMatrix, mModelView, *mSnapshot->transform);
1136        if (mTrackDirtyRegions && dirty) {
1137            dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
1138        }
1139    } else {
1140        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mIdentity);
1141        if (mTrackDirtyRegions && dirty) dirtyLayer(left, top, right, bottom);
1142    }
1143}
1144
1145void OpenGLRenderer::setupDrawPointUniforms() {
1146    int slot = mCaches.currentProgram->getUniform("pointSize");
1147    glUniform1f(slot, mDescription.pointSize);
1148}
1149
1150void OpenGLRenderer::setupDrawColorUniforms() {
1151    if (mColorSet || (mShader && mSetShaderColor)) {
1152        mCaches.currentProgram->setColor(mColorR, mColorG, mColorB, mColorA);
1153    }
1154}
1155
1156void OpenGLRenderer::setupDrawPureColorUniforms() {
1157    if (mSetShaderColor) {
1158        mCaches.currentProgram->setColor(mColorR, mColorG, mColorB, mColorA);
1159    }
1160}
1161
1162void OpenGLRenderer::setupDrawShaderUniforms(bool ignoreTransform) {
1163    if (mShader) {
1164        if (ignoreTransform) {
1165            mModelView.loadInverse(*mSnapshot->transform);
1166        }
1167        mShader->setupProgram(mCaches.currentProgram, mModelView, *mSnapshot, &mTextureUnit);
1168    }
1169}
1170
1171void OpenGLRenderer::setupDrawShaderIdentityUniforms() {
1172    if (mShader) {
1173        mShader->setupProgram(mCaches.currentProgram, mIdentity, *mSnapshot, &mTextureUnit);
1174    }
1175}
1176
1177void OpenGLRenderer::setupDrawColorFilterUniforms() {
1178    if (mColorFilter) {
1179        mColorFilter->setupProgram(mCaches.currentProgram);
1180    }
1181}
1182
1183void OpenGLRenderer::setupDrawSimpleMesh() {
1184    mCaches.bindMeshBuffer();
1185    glVertexAttribPointer(mCaches.currentProgram->position, 2, GL_FLOAT, GL_FALSE,
1186            gMeshStride, 0);
1187}
1188
1189void OpenGLRenderer::setupDrawTexture(GLuint texture) {
1190    bindTexture(texture);
1191    glUniform1i(mCaches.currentProgram->getUniform("sampler"), mTextureUnit++);
1192
1193    mTexCoordsSlot = mCaches.currentProgram->getAttrib("texCoords");
1194    glEnableVertexAttribArray(mTexCoordsSlot);
1195}
1196
1197void OpenGLRenderer::setupDrawExternalTexture(GLuint texture) {
1198    bindExternalTexture(texture);
1199    glUniform1i(mCaches.currentProgram->getUniform("sampler"), mTextureUnit++);
1200
1201    mTexCoordsSlot = mCaches.currentProgram->getAttrib("texCoords");
1202    glEnableVertexAttribArray(mTexCoordsSlot);
1203}
1204
1205void OpenGLRenderer::setupDrawTextureTransform() {
1206    mDescription.hasTextureTransform = true;
1207}
1208
1209void OpenGLRenderer::setupDrawTextureTransformUniforms(mat4& transform) {
1210    glUniformMatrix4fv(mCaches.currentProgram->getUniform("mainTextureTransform"), 1,
1211            GL_FALSE, &transform.data[0]);
1212}
1213
1214void OpenGLRenderer::setupDrawMesh(GLvoid* vertices, GLvoid* texCoords, GLuint vbo) {
1215    if (!vertices) {
1216        mCaches.bindMeshBuffer(vbo == 0 ? mCaches.meshBuffer : vbo);
1217    } else {
1218        mCaches.unbindMeshBuffer();
1219    }
1220    glVertexAttribPointer(mCaches.currentProgram->position, 2, GL_FLOAT, GL_FALSE,
1221            gMeshStride, vertices);
1222    if (mTexCoordsSlot >= 0) {
1223        glVertexAttribPointer(mTexCoordsSlot, 2, GL_FLOAT, GL_FALSE, gMeshStride, texCoords);
1224    }
1225}
1226
1227void OpenGLRenderer::setupDrawVertices(GLvoid* vertices) {
1228    mCaches.unbindMeshBuffer();
1229    glVertexAttribPointer(mCaches.currentProgram->position, 2, GL_FLOAT, GL_FALSE,
1230            gVertexStride, vertices);
1231}
1232
1233/**
1234 * Sets up the shader to draw an AA line. We draw AA lines with quads, where there is an
1235 * outer boundary that fades out to 0. The variables set in the shader define the proportion of
1236 * the width and length of the primitive occupied by the AA region. The vtxWidth and vtxLength
1237 * attributes (one per vertex) are values from zero to one that tells the fragment
1238 * shader where the fragment is in relation to the line width/length overall; these values are
1239 * then used to compute the proper color, based on whether the fragment lies in the fading AA
1240 * region of the line.
1241 * Note that we only pass down the width values in this setup function. The length coordinates
1242 * are set up for each individual segment.
1243 */
1244void OpenGLRenderer::setupDrawAALine(GLvoid* vertices, GLvoid* widthCoords,
1245        GLvoid* lengthCoords, float boundaryWidthProportion) {
1246    mCaches.unbindMeshBuffer();
1247    glVertexAttribPointer(mCaches.currentProgram->position, 2, GL_FLOAT, GL_FALSE,
1248            gAAVertexStride, vertices);
1249    int widthSlot = mCaches.currentProgram->getAttrib("vtxWidth");
1250    glEnableVertexAttribArray(widthSlot);
1251    glVertexAttribPointer(widthSlot, 1, GL_FLOAT, GL_FALSE, gAAVertexStride, widthCoords);
1252    int lengthSlot = mCaches.currentProgram->getAttrib("vtxLength");
1253    glEnableVertexAttribArray(lengthSlot);
1254    glVertexAttribPointer(lengthSlot, 1, GL_FLOAT, GL_FALSE, gAAVertexStride, lengthCoords);
1255    int boundaryWidthSlot = mCaches.currentProgram->getUniform("boundaryWidth");
1256    glUniform1f(boundaryWidthSlot, boundaryWidthProportion);
1257    // Setting the inverse value saves computations per-fragment in the shader
1258    int inverseBoundaryWidthSlot = mCaches.currentProgram->getUniform("inverseBoundaryWidth");
1259    glUniform1f(inverseBoundaryWidthSlot, (1 / boundaryWidthProportion));
1260}
1261
1262void OpenGLRenderer::finishDrawTexture() {
1263    glDisableVertexAttribArray(mTexCoordsSlot);
1264}
1265
1266///////////////////////////////////////////////////////////////////////////////
1267// Drawing
1268///////////////////////////////////////////////////////////////////////////////
1269
1270bool OpenGLRenderer::drawDisplayList(DisplayList* displayList, uint32_t width, uint32_t height,
1271        Rect& dirty, uint32_t level) {
1272    if (quickReject(0.0f, 0.0f, width, height)) {
1273        return false;
1274    }
1275
1276    // All the usual checks and setup operations (quickReject, setupDraw, etc.)
1277    // will be performed by the display list itself
1278    if (displayList) {
1279        return displayList->replay(*this, dirty, level);
1280    }
1281
1282    return false;
1283}
1284
1285void OpenGLRenderer::outputDisplayList(DisplayList* displayList, uint32_t level) {
1286    if (displayList) {
1287        displayList->output(*this, level);
1288    }
1289}
1290
1291void OpenGLRenderer::drawAlphaBitmap(Texture* texture, float left, float top, SkPaint* paint) {
1292    int alpha;
1293    SkXfermode::Mode mode;
1294    getAlphaAndMode(paint, &alpha, &mode);
1295
1296    setTextureWrapModes(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
1297
1298    float x = left;
1299    float y = top;
1300
1301    bool ignoreTransform = false;
1302    if (mSnapshot->transform->isPureTranslate()) {
1303        x = (int) floorf(left + mSnapshot->transform->getTranslateX() + 0.5f);
1304        y = (int) floorf(top + mSnapshot->transform->getTranslateY() + 0.5f);
1305        ignoreTransform = true;
1306    }
1307
1308    setupDraw();
1309    setupDrawWithTexture(true);
1310    if (paint) {
1311        setupDrawAlpha8Color(paint->getColor(), alpha);
1312    }
1313    setupDrawColorFilter();
1314    setupDrawShader();
1315    setupDrawBlending(true, mode);
1316    setupDrawProgram();
1317    setupDrawModelView(x, y, x + texture->width, y + texture->height, ignoreTransform);
1318    setupDrawTexture(texture->id);
1319    setupDrawPureColorUniforms();
1320    setupDrawColorFilterUniforms();
1321    setupDrawShaderUniforms();
1322    setupDrawMesh(NULL, (GLvoid*) gMeshTextureOffset);
1323
1324    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
1325
1326    finishDrawTexture();
1327}
1328
1329void OpenGLRenderer::drawBitmap(SkBitmap* bitmap, float left, float top, SkPaint* paint) {
1330    const float right = left + bitmap->width();
1331    const float bottom = top + bitmap->height();
1332
1333    if (quickReject(left, top, right, bottom)) {
1334        return;
1335    }
1336
1337    glActiveTexture(gTextureUnits[0]);
1338    Texture* texture = mCaches.textureCache.get(bitmap);
1339    if (!texture) return;
1340    const AutoTexture autoCleanup(texture);
1341
1342    if (bitmap->getConfig() == SkBitmap::kA8_Config) {
1343        drawAlphaBitmap(texture, left, top, paint);
1344    } else {
1345        drawTextureRect(left, top, right, bottom, texture, paint);
1346    }
1347}
1348
1349void OpenGLRenderer::drawBitmap(SkBitmap* bitmap, SkMatrix* matrix, SkPaint* paint) {
1350    Rect r(0.0f, 0.0f, bitmap->width(), bitmap->height());
1351    const mat4 transform(*matrix);
1352    transform.mapRect(r);
1353
1354    if (quickReject(r.left, r.top, r.right, r.bottom)) {
1355        return;
1356    }
1357
1358    glActiveTexture(gTextureUnits[0]);
1359    Texture* texture = mCaches.textureCache.get(bitmap);
1360    if (!texture) return;
1361    const AutoTexture autoCleanup(texture);
1362
1363    // This could be done in a cheaper way, all we need is pass the matrix
1364    // to the vertex shader. The save/restore is a bit overkill.
1365    save(SkCanvas::kMatrix_SaveFlag);
1366    concatMatrix(matrix);
1367    drawTextureRect(0.0f, 0.0f, bitmap->width(), bitmap->height(), texture, paint);
1368    restore();
1369}
1370
1371void OpenGLRenderer::drawBitmapMesh(SkBitmap* bitmap, int meshWidth, int meshHeight,
1372        float* vertices, int* colors, SkPaint* paint) {
1373    // TODO: Do a quickReject
1374    if (!vertices || mSnapshot->isIgnored()) {
1375        return;
1376    }
1377
1378    glActiveTexture(gTextureUnits[0]);
1379    Texture* texture = mCaches.textureCache.get(bitmap);
1380    if (!texture) return;
1381    const AutoTexture autoCleanup(texture);
1382    setTextureWrapModes(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
1383
1384    int alpha;
1385    SkXfermode::Mode mode;
1386    getAlphaAndMode(paint, &alpha, &mode);
1387
1388    const uint32_t count = meshWidth * meshHeight * 6;
1389
1390    float left = FLT_MAX;
1391    float top = FLT_MAX;
1392    float right = FLT_MIN;
1393    float bottom = FLT_MIN;
1394
1395#if RENDER_LAYERS_AS_REGIONS
1396    bool hasActiveLayer = hasLayer();
1397#else
1398    bool hasActiveLayer = false;
1399#endif
1400
1401    // TODO: Support the colors array
1402    TextureVertex mesh[count];
1403    TextureVertex* vertex = mesh;
1404    for (int32_t y = 0; y < meshHeight; y++) {
1405        for (int32_t x = 0; x < meshWidth; x++) {
1406            uint32_t i = (y * (meshWidth + 1) + x) * 2;
1407
1408            float u1 = float(x) / meshWidth;
1409            float u2 = float(x + 1) / meshWidth;
1410            float v1 = float(y) / meshHeight;
1411            float v2 = float(y + 1) / meshHeight;
1412
1413            int ax = i + (meshWidth + 1) * 2;
1414            int ay = ax + 1;
1415            int bx = i;
1416            int by = bx + 1;
1417            int cx = i + 2;
1418            int cy = cx + 1;
1419            int dx = i + (meshWidth + 1) * 2 + 2;
1420            int dy = dx + 1;
1421
1422            TextureVertex::set(vertex++, vertices[ax], vertices[ay], u1, v2);
1423            TextureVertex::set(vertex++, vertices[bx], vertices[by], u1, v1);
1424            TextureVertex::set(vertex++, vertices[cx], vertices[cy], u2, v1);
1425
1426            TextureVertex::set(vertex++, vertices[ax], vertices[ay], u1, v2);
1427            TextureVertex::set(vertex++, vertices[cx], vertices[cy], u2, v1);
1428            TextureVertex::set(vertex++, vertices[dx], vertices[dy], u2, v2);
1429
1430#if RENDER_LAYERS_AS_REGIONS
1431            if (hasActiveLayer) {
1432                // TODO: This could be optimized to avoid unnecessary ops
1433                left = fminf(left, fminf(vertices[ax], fminf(vertices[bx], vertices[cx])));
1434                top = fminf(top, fminf(vertices[ay], fminf(vertices[by], vertices[cy])));
1435                right = fmaxf(right, fmaxf(vertices[ax], fmaxf(vertices[bx], vertices[cx])));
1436                bottom = fmaxf(bottom, fmaxf(vertices[ay], fmaxf(vertices[by], vertices[cy])));
1437            }
1438#endif
1439        }
1440    }
1441
1442#if RENDER_LAYERS_AS_REGIONS
1443    if (hasActiveLayer) {
1444        dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
1445    }
1446#endif
1447
1448    drawTextureMesh(0.0f, 0.0f, 1.0f, 1.0f, texture->id, alpha / 255.0f,
1449            mode, texture->blend, &mesh[0].position[0], &mesh[0].texture[0],
1450            GL_TRIANGLES, count, false, false, 0, false, false);
1451}
1452
1453void OpenGLRenderer::drawBitmap(SkBitmap* bitmap,
1454         float srcLeft, float srcTop, float srcRight, float srcBottom,
1455         float dstLeft, float dstTop, float dstRight, float dstBottom,
1456         SkPaint* paint) {
1457    if (quickReject(dstLeft, dstTop, dstRight, dstBottom)) {
1458        return;
1459    }
1460
1461    glActiveTexture(gTextureUnits[0]);
1462    Texture* texture = mCaches.textureCache.get(bitmap);
1463    if (!texture) return;
1464    const AutoTexture autoCleanup(texture);
1465    setTextureWrapModes(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
1466
1467    const float width = texture->width;
1468    const float height = texture->height;
1469
1470    const float u1 = (srcLeft + 0.5f) / width;
1471    const float v1 = (srcTop + 0.5f)  / height;
1472    const float u2 = (srcRight - 0.5f) / width;
1473    const float v2 = (srcBottom - 0.5f) / height;
1474
1475    mCaches.unbindMeshBuffer();
1476    resetDrawTextureTexCoords(u1, v1, u2, v2);
1477
1478    int alpha;
1479    SkXfermode::Mode mode;
1480    getAlphaAndMode(paint, &alpha, &mode);
1481
1482    if (mSnapshot->transform->isPureTranslate()) {
1483        const float x = (int) floorf(dstLeft + mSnapshot->transform->getTranslateX() + 0.5f);
1484        const float y = (int) floorf(dstTop + mSnapshot->transform->getTranslateY() + 0.5f);
1485
1486        drawTextureMesh(x, y, x + (dstRight - dstLeft), y + (dstBottom - dstTop),
1487                texture->id, alpha / 255.0f, mode, texture->blend,
1488                &mMeshVertices[0].position[0], &mMeshVertices[0].texture[0],
1489                GL_TRIANGLE_STRIP, gMeshCount, false, true);
1490    } else {
1491        drawTextureMesh(dstLeft, dstTop, dstRight, dstBottom, texture->id, alpha / 255.0f,
1492                mode, texture->blend, &mMeshVertices[0].position[0], &mMeshVertices[0].texture[0],
1493                GL_TRIANGLE_STRIP, gMeshCount);
1494    }
1495
1496    resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
1497}
1498
1499void OpenGLRenderer::drawPatch(SkBitmap* bitmap, const int32_t* xDivs, const int32_t* yDivs,
1500        const uint32_t* colors, uint32_t width, uint32_t height, int8_t numColors,
1501        float left, float top, float right, float bottom, SkPaint* paint) {
1502    if (quickReject(left, top, right, bottom)) {
1503        return;
1504    }
1505
1506    glActiveTexture(gTextureUnits[0]);
1507    Texture* texture = mCaches.textureCache.get(bitmap);
1508    if (!texture) return;
1509    const AutoTexture autoCleanup(texture);
1510    setTextureWrapModes(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
1511
1512    int alpha;
1513    SkXfermode::Mode mode;
1514    getAlphaAndMode(paint, &alpha, &mode);
1515
1516    const Patch* mesh = mCaches.patchCache.get(bitmap->width(), bitmap->height(),
1517            right - left, bottom - top, xDivs, yDivs, colors, width, height, numColors);
1518
1519    if (mesh && mesh->verticesCount > 0) {
1520        const bool pureTranslate = mSnapshot->transform->isPureTranslate();
1521#if RENDER_LAYERS_AS_REGIONS
1522        // Mark the current layer dirty where we are going to draw the patch
1523        if (hasLayer() && mesh->hasEmptyQuads) {
1524            const float offsetX = left + mSnapshot->transform->getTranslateX();
1525            const float offsetY = top + mSnapshot->transform->getTranslateY();
1526            const size_t count = mesh->quads.size();
1527            for (size_t i = 0; i < count; i++) {
1528                const Rect& bounds = mesh->quads.itemAt(i);
1529                if (pureTranslate) {
1530                    const float x = (int) floorf(bounds.left + offsetX + 0.5f);
1531                    const float y = (int) floorf(bounds.top + offsetY + 0.5f);
1532                    dirtyLayer(x, y, x + bounds.getWidth(), y + bounds.getHeight());
1533                } else {
1534                    dirtyLayer(left + bounds.left, top + bounds.top,
1535                            left + bounds.right, top + bounds.bottom, *mSnapshot->transform);
1536                }
1537            }
1538        }
1539#endif
1540
1541        if (pureTranslate) {
1542            const float x = (int) floorf(left + mSnapshot->transform->getTranslateX() + 0.5f);
1543            const float y = (int) floorf(top + mSnapshot->transform->getTranslateY() + 0.5f);
1544
1545            drawTextureMesh(x, y, x + right - left, y + bottom - top, texture->id, alpha / 255.0f,
1546                    mode, texture->blend, (GLvoid*) 0, (GLvoid*) gMeshTextureOffset,
1547                    GL_TRIANGLES, mesh->verticesCount, false, true, mesh->meshBuffer,
1548                    true, !mesh->hasEmptyQuads);
1549        } else {
1550            drawTextureMesh(left, top, right, bottom, texture->id, alpha / 255.0f,
1551                    mode, texture->blend, (GLvoid*) 0, (GLvoid*) gMeshTextureOffset,
1552                    GL_TRIANGLES, mesh->verticesCount, false, false, mesh->meshBuffer,
1553                    true, !mesh->hasEmptyQuads);
1554        }
1555    }
1556}
1557
1558/**
1559 * This function uses a similar approach to that of AA lines in the drawLines() function.
1560 * We expand the rectangle by a half pixel in screen space on all sides, and use a fragment
1561 * shader to compute the translucency of the color, determined by whether a given pixel is
1562 * within that boundary region and how far into the region it is.
1563 */
1564void OpenGLRenderer::drawAARect(float left, float top, float right, float bottom,
1565        int color, SkXfermode::Mode mode) {
1566    float inverseScaleX = 1.0f;
1567    float inverseScaleY = 1.0f;
1568    // The quad that we use needs to account for scaling.
1569    if (!mSnapshot->transform->isPureTranslate()) {
1570        Matrix4 *mat = mSnapshot->transform;
1571        float m00 = mat->data[Matrix4::kScaleX];
1572        float m01 = mat->data[Matrix4::kSkewY];
1573        float m02 = mat->data[2];
1574        float m10 = mat->data[Matrix4::kSkewX];
1575        float m11 = mat->data[Matrix4::kScaleX];
1576        float m12 = mat->data[6];
1577        float scaleX = sqrt(m00 * m00 + m01 * m01);
1578        float scaleY = sqrt(m10 * m10 + m11 * m11);
1579        inverseScaleX = (scaleX != 0) ? (inverseScaleX / scaleX) : 0;
1580        inverseScaleY = (scaleY != 0) ? (inverseScaleY / scaleY) : 0;
1581    }
1582
1583    setupDraw();
1584    setupDrawAALine();
1585    setupDrawColor(color);
1586    setupDrawColorFilter();
1587    setupDrawShader();
1588    setupDrawBlending(true, mode);
1589    setupDrawProgram();
1590    setupDrawModelViewIdentity(true);
1591    setupDrawColorUniforms();
1592    setupDrawColorFilterUniforms();
1593    setupDrawShaderIdentityUniforms();
1594
1595    AAVertex rects[4];
1596    AAVertex* aaVertices = &rects[0];
1597    void* widthCoords = ((GLbyte*) aaVertices) + gVertexAAWidthOffset;
1598    void* lengthCoords = ((GLbyte*) aaVertices) + gVertexAALengthOffset;
1599
1600    float boundarySizeX = .5 * inverseScaleX;
1601    float boundarySizeY = .5 * inverseScaleY;
1602
1603    // Adjust the rect by the AA boundary padding
1604    left -= boundarySizeX;
1605    right += boundarySizeX;
1606    top -= boundarySizeY;
1607    bottom += boundarySizeY;
1608
1609    float width = right - left;
1610    float height = bottom - top;
1611
1612    float boundaryWidthProportion = (width != 0) ? (2 * boundarySizeX) / width : 0;
1613    float boundaryHeightProportion = (height != 0) ? (2 * boundarySizeY) / height : 0;
1614    setupDrawAALine((void*) aaVertices, widthCoords, lengthCoords, boundaryWidthProportion);
1615    int boundaryLengthSlot = mCaches.currentProgram->getUniform("boundaryLength");
1616    int inverseBoundaryLengthSlot = mCaches.currentProgram->getUniform("inverseBoundaryLength");
1617    glUniform1f(boundaryLengthSlot, boundaryHeightProportion);
1618    glUniform1f(inverseBoundaryLengthSlot, (1 / boundaryHeightProportion));
1619
1620    if (!quickReject(left, top, right, bottom)) {
1621        AAVertex::set(aaVertices++, left, bottom, 1, 1);
1622        AAVertex::set(aaVertices++, left, top, 1, 0);
1623        AAVertex::set(aaVertices++, right, bottom, 0, 1);
1624        AAVertex::set(aaVertices++, right, top, 0, 0);
1625        dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
1626        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
1627    }
1628}
1629
1630/**
1631 * We draw lines as quads (tristrips). Using GL_LINES can be difficult because the rasterization
1632 * rules for those lines produces some unexpected results, and may vary between hardware devices.
1633 * The basics of lines-as-quads is easy; we simply find the normal to the line and position the
1634 * corners of the quads on either side of each line endpoint, separated by the strokeWidth
1635 * of the line. Hairlines are more involved because we need to account for transform scaling
1636 * to end up with a one-pixel-wide line in screen space..
1637 * Anti-aliased lines add another factor to the approach. We use a specialized fragment shader
1638 * in combination with values that we calculate and pass down in this method. The basic approach
1639 * is that the quad we create contains both the core line area plus a bounding area in which
1640 * the translucent/AA pixels are drawn. The values we calculate tell the shader what
1641 * proportion of the width and the length of a given segment is represented by the boundary
1642 * region. The quad ends up being exactly .5 pixel larger in all directions than the non-AA quad.
1643 * The bounding region is actually 1 pixel wide on all sides (half pixel on the outside, half pixel
1644 * on the inside). This ends up giving the result we want, with pixels that are completely
1645 * 'inside' the line area being filled opaquely and the other pixels being filled according to
1646 * how far into the boundary region they are, which is determined by shader interpolation.
1647 */
1648void OpenGLRenderer::drawLines(float* points, int count, SkPaint* paint) {
1649    if (mSnapshot->isIgnored()) return;
1650
1651    const bool isAA = paint->isAntiAlias();
1652    // We use half the stroke width here because we're going to position the quad
1653    // corner vertices half of the width away from the line endpoints
1654    float halfStrokeWidth = paint->getStrokeWidth() * 0.5f;
1655    // A stroke width of 0 has a special meaning in Skia:
1656    // it draws a line 1 px wide regardless of current transform
1657    bool isHairLine = paint->getStrokeWidth() == 0.0f;
1658    float inverseScaleX = 1.0f;
1659    float inverseScaleY = 1.0f;
1660    bool scaled = false;
1661    int alpha;
1662    SkXfermode::Mode mode;
1663    int generatedVerticesCount = 0;
1664    int verticesCount = count;
1665    if (count > 4) {
1666        // Polyline: account for extra vertices needed for continuous tri-strip
1667        verticesCount += (count - 4);
1668    }
1669
1670    if (isHairLine || isAA) {
1671        // The quad that we use for AA and hairlines needs to account for scaling. For hairlines
1672        // the line on the screen should always be one pixel wide regardless of scale. For
1673        // AA lines, we only want one pixel of translucent boundary around the quad.
1674        if (!mSnapshot->transform->isPureTranslate()) {
1675            Matrix4 *mat = mSnapshot->transform;
1676            float m00 = mat->data[Matrix4::kScaleX];
1677            float m01 = mat->data[Matrix4::kSkewY];
1678            float m02 = mat->data[2];
1679            float m10 = mat->data[Matrix4::kSkewX];
1680            float m11 = mat->data[Matrix4::kScaleX];
1681            float m12 = mat->data[6];
1682            float scaleX = sqrt(m00*m00 + m01*m01);
1683            float scaleY = sqrt(m10*m10 + m11*m11);
1684            inverseScaleX = (scaleX != 0) ? (inverseScaleX / scaleX) : 0;
1685            inverseScaleY = (scaleY != 0) ? (inverseScaleY / scaleY) : 0;
1686            if (inverseScaleX != 1.0f || inverseScaleY != 1.0f) {
1687                scaled = true;
1688            }
1689        }
1690    }
1691
1692    getAlphaAndMode(paint, &alpha, &mode);
1693    setupDraw();
1694    if (isAA) {
1695        setupDrawAALine();
1696    }
1697    setupDrawColor(paint->getColor(), alpha);
1698    setupDrawColorFilter();
1699    setupDrawShader();
1700    if (isAA) {
1701        setupDrawBlending(true, mode);
1702    } else {
1703        setupDrawBlending(mode);
1704    }
1705    setupDrawProgram();
1706    setupDrawModelViewIdentity(true);
1707    setupDrawColorUniforms();
1708    setupDrawColorFilterUniforms();
1709    setupDrawShaderIdentityUniforms();
1710
1711    if (isHairLine) {
1712        // Set a real stroke width to be used in quad construction
1713        halfStrokeWidth = isAA? 1 : .5;
1714    } else if (isAA && !scaled) {
1715        // Expand boundary to enable AA calculations on the quad border
1716        halfStrokeWidth += .5f;
1717    }
1718    Vertex lines[verticesCount];
1719    Vertex* vertices = &lines[0];
1720    AAVertex wLines[verticesCount];
1721    AAVertex* aaVertices = &wLines[0];
1722    if (!isAA) {
1723        setupDrawVertices(vertices);
1724    } else {
1725        void* widthCoords = ((GLbyte*) aaVertices) + gVertexAAWidthOffset;
1726        void* lengthCoords = ((GLbyte*) aaVertices) + gVertexAALengthOffset;
1727        // innerProportion is the ratio of the inner (non-AA) part of the line to the total
1728        // AA stroke width (the base stroke width expanded by a half pixel on either side).
1729        // This value is used in the fragment shader to determine how to fill fragments.
1730        // We will need to calculate the actual width proportion on each segment for
1731        // scaled non-hairlines, since the boundary proportion may differ per-axis when scaled.
1732        float boundaryWidthProportion = 1 / (2 * halfStrokeWidth);
1733        setupDrawAALine((void*) aaVertices, widthCoords, lengthCoords, boundaryWidthProportion);
1734    }
1735
1736    AAVertex* prevAAVertex = NULL;
1737    Vertex* prevVertex = NULL;
1738
1739    int boundaryLengthSlot = -1;
1740    int inverseBoundaryLengthSlot = -1;
1741    int boundaryWidthSlot = -1;
1742    int inverseBoundaryWidthSlot = -1;
1743    for (int i = 0; i < count; i += 4) {
1744        // a = start point, b = end point
1745        vec2 a(points[i], points[i + 1]);
1746        vec2 b(points[i + 2], points[i + 3]);
1747        float length = 0;
1748        float boundaryLengthProportion = 0;
1749        float boundaryWidthProportion = 0;
1750
1751        // Find the normal to the line
1752        vec2 n = (b - a).copyNormalized() * halfStrokeWidth;
1753        if (isHairLine) {
1754            if (isAA) {
1755                float wideningFactor;
1756                if (fabs(n.x) >= fabs(n.y)) {
1757                    wideningFactor = fabs(1.0f / n.x);
1758                } else {
1759                    wideningFactor = fabs(1.0f / n.y);
1760                }
1761                n *= wideningFactor;
1762            }
1763            if (scaled) {
1764                n.x *= inverseScaleX;
1765                n.y *= inverseScaleY;
1766            }
1767        } else if (scaled) {
1768            // Extend n by .5 pixel on each side, post-transform
1769            vec2 extendedN = n.copyNormalized();
1770            extendedN /= 2;
1771            extendedN.x *= inverseScaleX;
1772            extendedN.y *= inverseScaleY;
1773            float extendedNLength = extendedN.length();
1774            // We need to set this value on the shader prior to drawing
1775            boundaryWidthProportion = extendedNLength / (halfStrokeWidth + extendedNLength);
1776            n += extendedN;
1777        }
1778        float x = n.x;
1779        n.x = -n.y;
1780        n.y = x;
1781
1782        // aa lines expand the endpoint vertices to encompass the AA boundary
1783        if (isAA) {
1784            vec2 abVector = (b - a);
1785            length = abVector.length();
1786            abVector.normalize();
1787            if (scaled) {
1788                abVector.x *= inverseScaleX;
1789                abVector.y *= inverseScaleY;
1790                float abLength = abVector.length();
1791                boundaryLengthProportion = abLength / (length + abLength);
1792            } else {
1793                boundaryLengthProportion = .5 / (length + 1);
1794            }
1795            abVector /= 2;
1796            a -= abVector;
1797            b += abVector;
1798        }
1799
1800        // Four corners of the rectangle defining a thick line
1801        vec2 p1 = a - n;
1802        vec2 p2 = a + n;
1803        vec2 p3 = b + n;
1804        vec2 p4 = b - n;
1805
1806
1807        const float left = fmin(p1.x, fmin(p2.x, fmin(p3.x, p4.x)));
1808        const float right = fmax(p1.x, fmax(p2.x, fmax(p3.x, p4.x)));
1809        const float top = fmin(p1.y, fmin(p2.y, fmin(p3.y, p4.y)));
1810        const float bottom = fmax(p1.y, fmax(p2.y, fmax(p3.y, p4.y)));
1811
1812        if (!quickReject(left, top, right, bottom)) {
1813            if (!isAA) {
1814                if (prevVertex != NULL) {
1815                    // Issue two repeat vertices to create degenerate triangles to bridge
1816                    // between the previous line and the new one. This is necessary because
1817                    // we are creating a single triangle_strip which will contain
1818                    // potentially discontinuous line segments.
1819                    Vertex::set(vertices++, prevVertex->position[0], prevVertex->position[1]);
1820                    Vertex::set(vertices++, p1.x, p1.y);
1821                    generatedVerticesCount += 2;
1822                }
1823                Vertex::set(vertices++, p1.x, p1.y);
1824                Vertex::set(vertices++, p2.x, p2.y);
1825                Vertex::set(vertices++, p4.x, p4.y);
1826                Vertex::set(vertices++, p3.x, p3.y);
1827                prevVertex = vertices - 1;
1828                generatedVerticesCount += 4;
1829            } else {
1830                if (!isHairLine && scaled) {
1831                    // Must set width proportions per-segment for scaled non-hairlines to use the
1832                    // correct AA boundary dimensions
1833                    if (boundaryWidthSlot < 0) {
1834                        boundaryWidthSlot =
1835                                mCaches.currentProgram->getUniform("boundaryWidth");
1836                        inverseBoundaryWidthSlot =
1837                                mCaches.currentProgram->getUniform("inverseBoundaryWidth");
1838                    }
1839                    glUniform1f(boundaryWidthSlot, boundaryWidthProportion);
1840                    glUniform1f(inverseBoundaryWidthSlot, (1 / boundaryWidthProportion));
1841                }
1842                if (boundaryLengthSlot < 0) {
1843                    boundaryLengthSlot = mCaches.currentProgram->getUniform("boundaryLength");
1844                    inverseBoundaryLengthSlot =
1845                            mCaches.currentProgram->getUniform("inverseBoundaryLength");
1846                }
1847                glUniform1f(boundaryLengthSlot, boundaryLengthProportion);
1848                glUniform1f(inverseBoundaryLengthSlot, (1 / boundaryLengthProportion));
1849
1850                if (prevAAVertex != NULL) {
1851                    // Issue two repeat vertices to create degenerate triangles to bridge
1852                    // between the previous line and the new one. This is necessary because
1853                    // we are creating a single triangle_strip which will contain
1854                    // potentially discontinuous line segments.
1855                    AAVertex::set(aaVertices++,prevAAVertex->position[0],
1856                            prevAAVertex->position[1], prevAAVertex->width, prevAAVertex->length);
1857                    AAVertex::set(aaVertices++, p4.x, p4.y, 1, 1);
1858                    generatedVerticesCount += 2;
1859                }
1860                AAVertex::set(aaVertices++, p4.x, p4.y, 1, 1);
1861                AAVertex::set(aaVertices++, p1.x, p1.y, 1, 0);
1862                AAVertex::set(aaVertices++, p3.x, p3.y, 0, 1);
1863                AAVertex::set(aaVertices++, p2.x, p2.y, 0, 0);
1864                prevAAVertex = aaVertices - 1;
1865                generatedVerticesCount += 4;
1866            }
1867            dirtyLayer(a.x == b.x ? left - 1 : left, a.y == b.y ? top - 1 : top,
1868                    a.x == b.x ? right: right, a.y == b.y ? bottom: bottom,
1869                    *mSnapshot->transform);
1870        }
1871    }
1872    if (generatedVerticesCount > 0) {
1873       glDrawArrays(GL_TRIANGLE_STRIP, 0, generatedVerticesCount);
1874    }
1875}
1876
1877void OpenGLRenderer::drawPoints(float* points, int count, SkPaint* paint) {
1878    if (mSnapshot->isIgnored()) return;
1879
1880    // TODO: The paint's cap style defines whether the points are square or circular
1881    // TODO: Handle AA for round points
1882
1883    // A stroke width of 0 has a special meaning in Skia:
1884    // it draws an unscaled 1px point
1885    float strokeWidth = paint->getStrokeWidth();
1886    const bool isHairLine = paint->getStrokeWidth() == 0.0f;
1887    if (isHairLine) {
1888        // Now that we know it's hairline, we can set the effective width, to be used later
1889        strokeWidth = 1.0f;
1890    }
1891    const float halfWidth = strokeWidth / 2;
1892    int alpha;
1893    SkXfermode::Mode mode;
1894    getAlphaAndMode(paint, &alpha, &mode);
1895
1896    int verticesCount = count >> 1;
1897    int generatedVerticesCount = 0;
1898
1899    TextureVertex pointsData[verticesCount];
1900    TextureVertex* vertex = &pointsData[0];
1901
1902    setupDraw();
1903    setupDrawPoint(strokeWidth);
1904    setupDrawColor(paint->getColor(), alpha);
1905    setupDrawColorFilter();
1906    setupDrawShader();
1907    setupDrawBlending(mode);
1908    setupDrawProgram();
1909    setupDrawModelViewIdentity(true);
1910    setupDrawColorUniforms();
1911    setupDrawColorFilterUniforms();
1912    setupDrawPointUniforms();
1913    setupDrawShaderIdentityUniforms();
1914    setupDrawMesh(vertex);
1915
1916    for (int i = 0; i < count; i += 2) {
1917        TextureVertex::set(vertex++, points[i], points[i + 1], 0.0f, 0.0f);
1918        generatedVerticesCount++;
1919        float left = points[i] - halfWidth;
1920        float right = points[i] + halfWidth;
1921        float top = points[i + 1] - halfWidth;
1922        float bottom = points [i + 1] + halfWidth;
1923        dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
1924    }
1925
1926    glDrawArrays(GL_POINTS, 0, generatedVerticesCount);
1927}
1928
1929void OpenGLRenderer::drawColor(int color, SkXfermode::Mode mode) {
1930    // No need to check against the clip, we fill the clip region
1931    if (mSnapshot->isIgnored()) return;
1932
1933    Rect& clip(*mSnapshot->clipRect);
1934    clip.snapToPixelBoundaries();
1935
1936    drawColorRect(clip.left, clip.top, clip.right, clip.bottom, color, mode, true);
1937}
1938
1939void OpenGLRenderer::drawShape(float left, float top, const PathTexture* texture, SkPaint* paint) {
1940    if (!texture) return;
1941    const AutoTexture autoCleanup(texture);
1942
1943    const float x = left + texture->left - texture->offset;
1944    const float y = top + texture->top - texture->offset;
1945
1946    drawPathTexture(texture, x, y, paint);
1947}
1948
1949void OpenGLRenderer::drawRoundRect(float left, float top, float right, float bottom,
1950        float rx, float ry, SkPaint* paint) {
1951    if (mSnapshot->isIgnored()) return;
1952
1953    glActiveTexture(gTextureUnits[0]);
1954    const PathTexture* texture = mCaches.roundRectShapeCache.getRoundRect(
1955            right - left, bottom - top, rx, ry, paint);
1956    drawShape(left, top, texture, paint);
1957}
1958
1959void OpenGLRenderer::drawCircle(float x, float y, float radius, SkPaint* paint) {
1960    if (mSnapshot->isIgnored()) return;
1961
1962    glActiveTexture(gTextureUnits[0]);
1963    const PathTexture* texture = mCaches.circleShapeCache.getCircle(radius, paint);
1964    drawShape(x - radius, y - radius, texture, paint);
1965}
1966
1967void OpenGLRenderer::drawOval(float left, float top, float right, float bottom, SkPaint* paint) {
1968    if (mSnapshot->isIgnored()) return;
1969
1970    glActiveTexture(gTextureUnits[0]);
1971    const PathTexture* texture = mCaches.ovalShapeCache.getOval(right - left, bottom - top, paint);
1972    drawShape(left, top, texture, paint);
1973}
1974
1975void OpenGLRenderer::drawArc(float left, float top, float right, float bottom,
1976        float startAngle, float sweepAngle, bool useCenter, SkPaint* paint) {
1977    if (mSnapshot->isIgnored()) return;
1978
1979    if (fabs(sweepAngle) >= 360.0f) {
1980        drawOval(left, top, right, bottom, paint);
1981        return;
1982    }
1983
1984    glActiveTexture(gTextureUnits[0]);
1985    const PathTexture* texture = mCaches.arcShapeCache.getArc(right - left, bottom - top,
1986            startAngle, sweepAngle, useCenter, paint);
1987    drawShape(left, top, texture, paint);
1988}
1989
1990void OpenGLRenderer::drawRectAsShape(float left, float top, float right, float bottom,
1991        SkPaint* paint) {
1992    if (mSnapshot->isIgnored()) return;
1993
1994    glActiveTexture(gTextureUnits[0]);
1995    const PathTexture* texture = mCaches.rectShapeCache.getRect(right - left, bottom - top, paint);
1996    drawShape(left, top, texture, paint);
1997}
1998
1999void OpenGLRenderer::drawRect(float left, float top, float right, float bottom, SkPaint* p) {
2000    if (p->getStyle() != SkPaint::kFill_Style) {
2001        drawRectAsShape(left, top, right, bottom, p);
2002        return;
2003    }
2004
2005    if (quickReject(left, top, right, bottom)) {
2006        return;
2007    }
2008
2009    SkXfermode::Mode mode;
2010    if (!mCaches.extensions.hasFramebufferFetch()) {
2011        const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode);
2012        if (!isMode) {
2013            // Assume SRC_OVER
2014            mode = SkXfermode::kSrcOver_Mode;
2015        }
2016    } else {
2017        mode = getXfermode(p->getXfermode());
2018    }
2019
2020    int color = p->getColor();
2021    if (p->isAntiAlias() && !mSnapshot->transform->isSimple()) {
2022        drawAARect(left, top, right, bottom, color, mode);
2023    } else {
2024        drawColorRect(left, top, right, bottom, color, mode);
2025    }
2026}
2027
2028void OpenGLRenderer::drawText(const char* text, int bytesCount, int count,
2029        float x, float y, SkPaint* paint) {
2030    if (text == NULL || count == 0) {
2031        return;
2032    }
2033    if (mSnapshot->isIgnored()) return;
2034
2035    // TODO: We should probably make a copy of the paint instead of modifying
2036    //       it; modifying the paint will change its generationID the first
2037    //       time, which might impact caches. More investigation needed to
2038    //       see if it matters.
2039    //       If we make a copy, then drawTextDecorations() should *not* make
2040    //       its own copy as it does right now.
2041    paint->setAntiAlias(true);
2042#if RENDER_TEXT_AS_GLYPHS
2043    paint->setTextEncoding(SkPaint::kGlyphID_TextEncoding);
2044#endif
2045
2046    float length = -1.0f;
2047    switch (paint->getTextAlign()) {
2048        case SkPaint::kCenter_Align:
2049            length = paint->measureText(text, bytesCount);
2050            x -= length / 2.0f;
2051            break;
2052        case SkPaint::kRight_Align:
2053            length = paint->measureText(text, bytesCount);
2054            x -= length;
2055            break;
2056        default:
2057            break;
2058    }
2059
2060    const float oldX = x;
2061    const float oldY = y;
2062    const bool pureTranslate = mSnapshot->transform->isPureTranslate();
2063    if (pureTranslate) {
2064        x = (int) floorf(x + mSnapshot->transform->getTranslateX() + 0.5f);
2065        y = (int) floorf(y + mSnapshot->transform->getTranslateY() + 0.5f);
2066    }
2067
2068    FontRenderer& fontRenderer = mCaches.fontRenderer.getFontRenderer(paint);
2069    fontRenderer.setFont(paint, SkTypeface::UniqueID(paint->getTypeface()),
2070            paint->getTextSize());
2071
2072    int alpha;
2073    SkXfermode::Mode mode;
2074    getAlphaAndMode(paint, &alpha, &mode);
2075
2076    if (mHasShadow) {
2077        mCaches.dropShadowCache.setFontRenderer(fontRenderer);
2078        const ShadowTexture* shadow = mCaches.dropShadowCache.get(
2079                paint, text, bytesCount, count, mShadowRadius);
2080        const AutoTexture autoCleanup(shadow);
2081
2082        const float sx = oldX - shadow->left + mShadowDx;
2083        const float sy = oldY - shadow->top + mShadowDy;
2084
2085        const int shadowAlpha = ((mShadowColor >> 24) & 0xFF);
2086        int shadowColor = mShadowColor;
2087        if (mShader) {
2088            shadowColor = 0xffffffff;
2089        }
2090
2091        glActiveTexture(gTextureUnits[0]);
2092        setupDraw();
2093        setupDrawWithTexture(true);
2094        setupDrawAlpha8Color(shadowColor, shadowAlpha < 255 ? shadowAlpha : alpha);
2095        setupDrawColorFilter();
2096        setupDrawShader();
2097        setupDrawBlending(true, mode);
2098        setupDrawProgram();
2099        setupDrawModelView(sx, sy, sx + shadow->width, sy + shadow->height);
2100        setupDrawTexture(shadow->id);
2101        setupDrawPureColorUniforms();
2102        setupDrawColorFilterUniforms();
2103        setupDrawShaderUniforms();
2104        setupDrawMesh(NULL, (GLvoid*) gMeshTextureOffset);
2105
2106        glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
2107
2108        finishDrawTexture();
2109    }
2110
2111    if (paint->getAlpha() == 0 && paint->getXfermode() == NULL) {
2112        return;
2113    }
2114
2115    // Pick the appropriate texture filtering
2116    bool linearFilter = mSnapshot->transform->changesBounds();
2117    if (pureTranslate && !linearFilter) {
2118        linearFilter = fabs(y - (int) y) > 0.0f || fabs(x - (int) x) > 0.0f;
2119    }
2120
2121    glActiveTexture(gTextureUnits[0]);
2122    setupDraw();
2123    setupDrawDirtyRegionsDisabled();
2124    setupDrawWithTexture(true);
2125    setupDrawAlpha8Color(paint->getColor(), alpha);
2126    setupDrawColorFilter();
2127    setupDrawShader();
2128    setupDrawBlending(true, mode);
2129    setupDrawProgram();
2130    setupDrawModelView(x, y, x, y, pureTranslate, true);
2131    setupDrawTexture(fontRenderer.getTexture(linearFilter));
2132    setupDrawPureColorUniforms();
2133    setupDrawColorFilterUniforms();
2134    setupDrawShaderUniforms(pureTranslate);
2135
2136    const Rect* clip = pureTranslate ? mSnapshot->clipRect : &mSnapshot->getLocalClip();
2137    Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
2138
2139#if RENDER_LAYERS_AS_REGIONS
2140    bool hasActiveLayer = hasLayer();
2141#else
2142    bool hasActiveLayer = false;
2143#endif
2144    mCaches.unbindMeshBuffer();
2145
2146    // Tell font renderer the locations of position and texture coord
2147    // attributes so it can bind its data properly
2148    int positionSlot = mCaches.currentProgram->position;
2149    fontRenderer.setAttributeBindingSlots(positionSlot, mTexCoordsSlot);
2150    if (fontRenderer.renderText(paint, clip, text, 0, bytesCount, count, x, y,
2151            hasActiveLayer ? &bounds : NULL)) {
2152#if RENDER_LAYERS_AS_REGIONS
2153        if (hasActiveLayer) {
2154            if (!pureTranslate) {
2155                mSnapshot->transform->mapRect(bounds);
2156            }
2157            dirtyLayerUnchecked(bounds, getRegion());
2158        }
2159#endif
2160    }
2161
2162    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
2163    glDisableVertexAttribArray(mCaches.currentProgram->getAttrib("texCoords"));
2164
2165    drawTextDecorations(text, bytesCount, length, oldX, oldY, paint);
2166}
2167
2168void OpenGLRenderer::drawPath(SkPath* path, SkPaint* paint) {
2169    if (mSnapshot->isIgnored()) return;
2170
2171    glActiveTexture(gTextureUnits[0]);
2172
2173    const PathTexture* texture = mCaches.pathCache.get(path, paint);
2174    if (!texture) return;
2175    const AutoTexture autoCleanup(texture);
2176
2177    const float x = texture->left - texture->offset;
2178    const float y = texture->top - texture->offset;
2179
2180    drawPathTexture(texture, x, y, paint);
2181}
2182
2183void OpenGLRenderer::drawLayer(Layer* layer, float x, float y, SkPaint* paint) {
2184    if (!layer || quickReject(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight())) {
2185        return;
2186    }
2187
2188    glActiveTexture(gTextureUnits[0]);
2189
2190    int alpha;
2191    SkXfermode::Mode mode;
2192    getAlphaAndMode(paint, &alpha, &mode);
2193
2194    layer->setAlpha(alpha, mode);
2195
2196#if RENDER_LAYERS_AS_REGIONS
2197    if (!layer->region.isEmpty()) {
2198        if (layer->region.isRect()) {
2199            composeLayerRect(layer, layer->regionRect);
2200        } else if (layer->mesh) {
2201            const float a = alpha / 255.0f;
2202            const Rect& rect = layer->layer;
2203
2204            setupDraw();
2205            setupDrawWithTexture();
2206            setupDrawColor(a, a, a, a);
2207            setupDrawColorFilter();
2208            setupDrawBlending(layer->isBlend() || a < 1.0f, layer->getMode(), false);
2209            setupDrawProgram();
2210            setupDrawPureColorUniforms();
2211            setupDrawColorFilterUniforms();
2212            setupDrawTexture(layer->getTexture());
2213            if (mSnapshot->transform->isPureTranslate()) {
2214                x = (int) floorf(x + mSnapshot->transform->getTranslateX() + 0.5f);
2215                y = (int) floorf(y + mSnapshot->transform->getTranslateY() + 0.5f);
2216
2217                layer->setFilter(GL_NEAREST, GL_NEAREST);
2218                setupDrawModelViewTranslate(x, y,
2219                        x + layer->layer.getWidth(), y + layer->layer.getHeight(), true);
2220            } else {
2221                layer->setFilter(GL_LINEAR, GL_LINEAR);
2222                setupDrawModelViewTranslate(x, y,
2223                        x + layer->layer.getWidth(), y + layer->layer.getHeight());
2224            }
2225            setupDrawMesh(&layer->mesh[0].position[0], &layer->mesh[0].texture[0]);
2226
2227            glDrawElements(GL_TRIANGLES, layer->meshElementCount,
2228                    GL_UNSIGNED_SHORT, layer->meshIndices);
2229
2230            finishDrawTexture();
2231
2232#if DEBUG_LAYERS_AS_REGIONS
2233            drawRegionRects(layer->region);
2234#endif
2235        }
2236    }
2237#else
2238    const Rect r(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight());
2239    composeLayerRect(layer, r);
2240#endif
2241}
2242
2243///////////////////////////////////////////////////////////////////////////////
2244// Shaders
2245///////////////////////////////////////////////////////////////////////////////
2246
2247void OpenGLRenderer::resetShader() {
2248    mShader = NULL;
2249}
2250
2251void OpenGLRenderer::setupShader(SkiaShader* shader) {
2252    mShader = shader;
2253    if (mShader) {
2254        mShader->set(&mCaches.textureCache, &mCaches.gradientCache);
2255    }
2256}
2257
2258///////////////////////////////////////////////////////////////////////////////
2259// Color filters
2260///////////////////////////////////////////////////////////////////////////////
2261
2262void OpenGLRenderer::resetColorFilter() {
2263    mColorFilter = NULL;
2264}
2265
2266void OpenGLRenderer::setupColorFilter(SkiaColorFilter* filter) {
2267    mColorFilter = filter;
2268}
2269
2270///////////////////////////////////////////////////////////////////////////////
2271// Drop shadow
2272///////////////////////////////////////////////////////////////////////////////
2273
2274void OpenGLRenderer::resetShadow() {
2275    mHasShadow = false;
2276}
2277
2278void OpenGLRenderer::setupShadow(float radius, float dx, float dy, int color) {
2279    mHasShadow = true;
2280    mShadowRadius = radius;
2281    mShadowDx = dx;
2282    mShadowDy = dy;
2283    mShadowColor = color;
2284}
2285
2286///////////////////////////////////////////////////////////////////////////////
2287// Drawing implementation
2288///////////////////////////////////////////////////////////////////////////////
2289
2290void OpenGLRenderer::drawPathTexture(const PathTexture* texture,
2291        float x, float y, SkPaint* paint) {
2292    if (quickReject(x, y, x + texture->width, y + texture->height)) {
2293        return;
2294    }
2295
2296    int alpha;
2297    SkXfermode::Mode mode;
2298    getAlphaAndMode(paint, &alpha, &mode);
2299
2300    setupDraw();
2301    setupDrawWithTexture(true);
2302    setupDrawAlpha8Color(paint->getColor(), alpha);
2303    setupDrawColorFilter();
2304    setupDrawShader();
2305    setupDrawBlending(true, mode);
2306    setupDrawProgram();
2307    setupDrawModelView(x, y, x + texture->width, y + texture->height);
2308    setupDrawTexture(texture->id);
2309    setupDrawPureColorUniforms();
2310    setupDrawColorFilterUniforms();
2311    setupDrawShaderUniforms();
2312    setupDrawMesh(NULL, (GLvoid*) gMeshTextureOffset);
2313
2314    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
2315
2316    finishDrawTexture();
2317}
2318
2319// Same values used by Skia
2320#define kStdStrikeThru_Offset   (-6.0f / 21.0f)
2321#define kStdUnderline_Offset    (1.0f / 9.0f)
2322#define kStdUnderline_Thickness (1.0f / 18.0f)
2323
2324void OpenGLRenderer::drawTextDecorations(const char* text, int bytesCount, float length,
2325        float x, float y, SkPaint* paint) {
2326    // Handle underline and strike-through
2327    uint32_t flags = paint->getFlags();
2328    if (flags & (SkPaint::kUnderlineText_Flag | SkPaint::kStrikeThruText_Flag)) {
2329        SkPaint paintCopy(*paint);
2330        float underlineWidth = length;
2331        // If length is > 0.0f, we already measured the text for the text alignment
2332        if (length <= 0.0f) {
2333            underlineWidth = paintCopy.measureText(text, bytesCount);
2334        }
2335
2336        float offsetX = 0;
2337        switch (paintCopy.getTextAlign()) {
2338            case SkPaint::kCenter_Align:
2339                offsetX = underlineWidth * 0.5f;
2340                break;
2341            case SkPaint::kRight_Align:
2342                offsetX = underlineWidth;
2343                break;
2344            default:
2345                break;
2346        }
2347
2348        if (underlineWidth > 0.0f) {
2349            const float textSize = paintCopy.getTextSize();
2350            const float strokeWidth = fmax(textSize * kStdUnderline_Thickness, 1.0f);
2351
2352            const float left = x - offsetX;
2353            float top = 0.0f;
2354
2355            int linesCount = 0;
2356            if (flags & SkPaint::kUnderlineText_Flag) linesCount++;
2357            if (flags & SkPaint::kStrikeThruText_Flag) linesCount++;
2358
2359            const int pointsCount = 4 * linesCount;
2360            float points[pointsCount];
2361            int currentPoint = 0;
2362
2363            if (flags & SkPaint::kUnderlineText_Flag) {
2364                top = y + textSize * kStdUnderline_Offset;
2365                points[currentPoint++] = left;
2366                points[currentPoint++] = top;
2367                points[currentPoint++] = left + underlineWidth;
2368                points[currentPoint++] = top;
2369            }
2370
2371            if (flags & SkPaint::kStrikeThruText_Flag) {
2372                top = y + textSize * kStdStrikeThru_Offset;
2373                points[currentPoint++] = left;
2374                points[currentPoint++] = top;
2375                points[currentPoint++] = left + underlineWidth;
2376                points[currentPoint++] = top;
2377            }
2378
2379            paintCopy.setStrokeWidth(strokeWidth);
2380
2381            drawLines(&points[0], pointsCount, &paintCopy);
2382        }
2383    }
2384}
2385
2386void OpenGLRenderer::drawColorRect(float left, float top, float right, float bottom,
2387        int color, SkXfermode::Mode mode, bool ignoreTransform) {
2388    // If a shader is set, preserve only the alpha
2389    if (mShader) {
2390        color |= 0x00ffffff;
2391    }
2392
2393    setupDraw();
2394    setupDrawColor(color);
2395    setupDrawShader();
2396    setupDrawColorFilter();
2397    setupDrawBlending(mode);
2398    setupDrawProgram();
2399    setupDrawModelView(left, top, right, bottom, ignoreTransform);
2400    setupDrawColorUniforms();
2401    setupDrawShaderUniforms(ignoreTransform);
2402    setupDrawColorFilterUniforms();
2403    setupDrawSimpleMesh();
2404
2405    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
2406}
2407
2408void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom,
2409        Texture* texture, SkPaint* paint) {
2410    int alpha;
2411    SkXfermode::Mode mode;
2412    getAlphaAndMode(paint, &alpha, &mode);
2413
2414    setTextureWrapModes(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
2415
2416    if (mSnapshot->transform->isPureTranslate()) {
2417        const float x = (int) floorf(left + mSnapshot->transform->getTranslateX() + 0.5f);
2418        const float y = (int) floorf(top + mSnapshot->transform->getTranslateY() + 0.5f);
2419
2420        drawTextureMesh(x, y, x + texture->width, y + texture->height, texture->id,
2421                alpha / 255.0f, mode, texture->blend, (GLvoid*) NULL,
2422                (GLvoid*) gMeshTextureOffset, GL_TRIANGLE_STRIP, gMeshCount, false, true);
2423    } else {
2424        drawTextureMesh(left, top, right, bottom, texture->id, alpha / 255.0f, mode,
2425                texture->blend, (GLvoid*) NULL, (GLvoid*) gMeshTextureOffset,
2426                GL_TRIANGLE_STRIP, gMeshCount);
2427    }
2428}
2429
2430void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom,
2431        GLuint texture, float alpha, SkXfermode::Mode mode, bool blend) {
2432    drawTextureMesh(left, top, right, bottom, texture, alpha, mode, blend,
2433            (GLvoid*) NULL, (GLvoid*) gMeshTextureOffset, GL_TRIANGLE_STRIP, gMeshCount);
2434}
2435
2436void OpenGLRenderer::drawTextureMesh(float left, float top, float right, float bottom,
2437        GLuint texture, float alpha, SkXfermode::Mode mode, bool blend,
2438        GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
2439        bool swapSrcDst, bool ignoreTransform, GLuint vbo, bool ignoreScale, bool dirty) {
2440
2441    setupDraw();
2442    setupDrawWithTexture();
2443    setupDrawColor(alpha, alpha, alpha, alpha);
2444    setupDrawColorFilter();
2445    setupDrawBlending(blend, mode, swapSrcDst);
2446    setupDrawProgram();
2447    if (!dirty) {
2448        setupDrawDirtyRegionsDisabled();
2449    }
2450    if (!ignoreScale) {
2451        setupDrawModelView(left, top, right, bottom, ignoreTransform);
2452    } else {
2453        setupDrawModelViewTranslate(left, top, right, bottom, ignoreTransform);
2454    }
2455    setupDrawPureColorUniforms();
2456    setupDrawColorFilterUniforms();
2457    setupDrawTexture(texture);
2458    setupDrawMesh(vertices, texCoords, vbo);
2459
2460    glDrawArrays(drawMode, 0, elementsCount);
2461
2462    finishDrawTexture();
2463}
2464
2465void OpenGLRenderer::chooseBlending(bool blend, SkXfermode::Mode mode,
2466        ProgramDescription& description, bool swapSrcDst) {
2467    blend = blend || mode != SkXfermode::kSrcOver_Mode;
2468    if (blend) {
2469        if (mode < SkXfermode::kPlus_Mode) {
2470            if (!mCaches.blend) {
2471                glEnable(GL_BLEND);
2472            }
2473
2474            GLenum sourceMode = swapSrcDst ? gBlendsSwap[mode].src : gBlends[mode].src;
2475            GLenum destMode = swapSrcDst ? gBlendsSwap[mode].dst : gBlends[mode].dst;
2476
2477            if (sourceMode != mCaches.lastSrcMode || destMode != mCaches.lastDstMode) {
2478                glBlendFunc(sourceMode, destMode);
2479                mCaches.lastSrcMode = sourceMode;
2480                mCaches.lastDstMode = destMode;
2481            }
2482        } else {
2483            // These blend modes are not supported by OpenGL directly and have
2484            // to be implemented using shaders. Since the shader will perform
2485            // the blending, turn blending off here
2486            if (mCaches.extensions.hasFramebufferFetch()) {
2487                description.framebufferMode = mode;
2488                description.swapSrcDst = swapSrcDst;
2489            }
2490
2491            if (mCaches.blend) {
2492                glDisable(GL_BLEND);
2493            }
2494            blend = false;
2495        }
2496    } else if (mCaches.blend) {
2497        glDisable(GL_BLEND);
2498    }
2499    mCaches.blend = blend;
2500}
2501
2502bool OpenGLRenderer::useProgram(Program* program) {
2503    if (!program->isInUse()) {
2504        if (mCaches.currentProgram != NULL) mCaches.currentProgram->remove();
2505        program->use();
2506        mCaches.currentProgram = program;
2507        return false;
2508    }
2509    return true;
2510}
2511
2512void OpenGLRenderer::resetDrawTextureTexCoords(float u1, float v1, float u2, float v2) {
2513    TextureVertex* v = &mMeshVertices[0];
2514    TextureVertex::setUV(v++, u1, v1);
2515    TextureVertex::setUV(v++, u2, v1);
2516    TextureVertex::setUV(v++, u1, v2);
2517    TextureVertex::setUV(v++, u2, v2);
2518}
2519
2520void OpenGLRenderer::getAlphaAndMode(SkPaint* paint, int* alpha, SkXfermode::Mode* mode) {
2521    if (paint) {
2522        if (!mCaches.extensions.hasFramebufferFetch()) {
2523            const bool isMode = SkXfermode::IsMode(paint->getXfermode(), mode);
2524            if (!isMode) {
2525                // Assume SRC_OVER
2526                *mode = SkXfermode::kSrcOver_Mode;
2527            }
2528        } else {
2529            *mode = getXfermode(paint->getXfermode());
2530        }
2531
2532        // Skia draws using the color's alpha channel if < 255
2533        // Otherwise, it uses the paint's alpha
2534        int color = paint->getColor();
2535        *alpha = (color >> 24) & 0xFF;
2536        if (*alpha == 255) {
2537            *alpha = paint->getAlpha();
2538        }
2539    } else {
2540        *mode = SkXfermode::kSrcOver_Mode;
2541        *alpha = 255;
2542    }
2543}
2544
2545SkXfermode::Mode OpenGLRenderer::getXfermode(SkXfermode* mode) {
2546    SkXfermode::Mode resultMode;
2547    if (!SkXfermode::AsMode(mode, &resultMode)) {
2548        resultMode = SkXfermode::kSrcOver_Mode;
2549    }
2550    return resultMode;
2551}
2552
2553void OpenGLRenderer::setTextureWrapModes(Texture* texture, GLenum wrapS, GLenum wrapT) {
2554    bool bound = false;
2555    if (wrapS != texture->wrapS) {
2556        glBindTexture(GL_TEXTURE_2D, texture->id);
2557        bound = true;
2558        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrapS);
2559        texture->wrapS = wrapS;
2560    }
2561    if (wrapT != texture->wrapT) {
2562        if (!bound) {
2563            glBindTexture(GL_TEXTURE_2D, texture->id);
2564        }
2565        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrapT);
2566        texture->wrapT = wrapT;
2567    }
2568}
2569
2570}; // namespace uirenderer
2571}; // namespace android
2572