OpenGLRenderer.cpp revision 694b519ac647fe998fd396fe0784cc8e179aadc4 
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 <cutils/properties.h>
27#include <utils/Log.h>
28
29#include "OpenGLRenderer.h"
30
31namespace android {
32namespace uirenderer {
33
34///////////////////////////////////////////////////////////////////////////////
35// Defines
36///////////////////////////////////////////////////////////////////////////////
37
38// These properties are defined in mega-bytes
39#define PROPERTY_TEXTURE_CACHE_SIZE "ro.hwui.texture_cache_size"
40#define PROPERTY_LAYER_CACHE_SIZE "ro.hwui.layer_cache_size"
41#define PROPERTY_GRADIENT_CACHE_SIZE "ro.hwui.gradient_cache_size"
42
43#define DEFAULT_TEXTURE_CACHE_SIZE 20.0f
44#define DEFAULT_LAYER_CACHE_SIZE 10.0f
45#define DEFAULT_PATCH_CACHE_SIZE 100
46#define DEFAULT_GRADIENT_CACHE_SIZE 0.5f
47
48// Converts a number of mega-bytes into bytes
49#define MB(s) s * 1024 * 1024
50
51// Generates simple and textured vertices
52#define SV(x, y) { { x, y } }
53#define FV(x, y, u, v) { { x, y }, { u, v } }
54
55///////////////////////////////////////////////////////////////////////////////
56// Globals
57///////////////////////////////////////////////////////////////////////////////
58
59static const SimpleVertex gDrawColorVertices[] = {
60        SV(0.0f, 0.0f),
61        SV(1.0f, 0.0f),
62        SV(0.0f, 1.0f),
63        SV(1.0f, 1.0f)
64};
65static const GLsizei gDrawColorVertexStride = sizeof(SimpleVertex);
66static const GLsizei gDrawColorVertexCount = 4;
67
68// This array is never used directly but used as a memcpy source in the
69// OpenGLRenderer constructor
70static const TextureVertex gDrawTextureVertices[] = {
71        FV(0.0f, 0.0f, 0.0f, 0.0f),
72        FV(1.0f, 0.0f, 1.0f, 0.0f),
73        FV(0.0f, 1.0f, 0.0f, 1.0f),
74        FV(1.0f, 1.0f, 1.0f, 1.0f)
75};
76static const GLsizei gDrawTextureVertexStride = sizeof(TextureVertex);
77static const GLsizei gDrawTextureVertexCount = 4;
78
79// In this array, the index of each Blender equals the value of the first
80// entry. For instance, gBlends[1] == gBlends[SkXfermode::kSrc_Mode]
81static const Blender gBlends[] = {
82        { SkXfermode::kClear_Mode,   GL_ZERO,                 GL_ZERO },
83        { SkXfermode::kSrc_Mode,     GL_ONE,                  GL_ZERO },
84        { SkXfermode::kDst_Mode,     GL_ZERO,                 GL_ONE },
85        { SkXfermode::kSrcOver_Mode, GL_ONE,                  GL_ONE_MINUS_SRC_ALPHA },
86        { SkXfermode::kDstOver_Mode, GL_ONE_MINUS_DST_ALPHA,  GL_ONE },
87        { SkXfermode::kSrcIn_Mode,   GL_DST_ALPHA,            GL_ZERO },
88        { SkXfermode::kDstIn_Mode,   GL_ZERO,                 GL_SRC_ALPHA },
89        { SkXfermode::kSrcOut_Mode,  GL_ONE_MINUS_DST_ALPHA,  GL_ZERO },
90        { SkXfermode::kDstOut_Mode,  GL_ZERO,                 GL_ONE_MINUS_SRC_ALPHA },
91        { SkXfermode::kSrcATop_Mode, GL_DST_ALPHA,            GL_ONE_MINUS_SRC_ALPHA },
92        { SkXfermode::kDstATop_Mode, GL_ONE_MINUS_DST_ALPHA,  GL_SRC_ALPHA },
93        { SkXfermode::kXor_Mode,     GL_ONE_MINUS_DST_ALPHA,  GL_ONE_MINUS_SRC_ALPHA }
94};
95
96static const GLint gTileModes[] = {
97        GL_CLAMP_TO_EDGE,   // == SkShader::kClamp_TileMode
98        GL_REPEAT,          // == SkShader::kRepeat_Mode
99        GL_MIRRORED_REPEAT  // == SkShader::kMirror_TileMode
100};
101
102///////////////////////////////////////////////////////////////////////////////
103// Constructors/destructor
104///////////////////////////////////////////////////////////////////////////////
105
106OpenGLRenderer::OpenGLRenderer():
107        mBlend(false), mLastSrcMode(GL_ZERO), mLastDstMode(GL_ZERO),
108        mTextureCache(MB(DEFAULT_TEXTURE_CACHE_SIZE)),
109        mLayerCache(MB(DEFAULT_LAYER_CACHE_SIZE)),
110        mGradientCache(MB(DEFAULT_GRADIENT_CACHE_SIZE)),
111        mPatchCache(DEFAULT_PATCH_CACHE_SIZE) {
112    LOGD("Create OpenGLRenderer");
113
114    char property[PROPERTY_VALUE_MAX];
115    if (property_get(PROPERTY_TEXTURE_CACHE_SIZE, property, NULL) > 0) {
116        LOGD("  Setting texture cache size to %sMB", property);
117        mTextureCache.setMaxSize(MB(atof(property)));
118    } else {
119        LOGD("  Using default texture cache size of %.2fMB", DEFAULT_TEXTURE_CACHE_SIZE);
120    }
121
122    if (property_get(PROPERTY_LAYER_CACHE_SIZE, property, NULL) > 0) {
123        LOGD("  Setting layer cache size to %sMB", property);
124        mLayerCache.setMaxSize(MB(atof(property)));
125    } else {
126        LOGD("  Using default layer cache size of %.2fMB", DEFAULT_LAYER_CACHE_SIZE);
127    }
128
129    if (property_get(PROPERTY_GRADIENT_CACHE_SIZE, property, NULL) > 0) {
130        LOGD("  Setting gradient cache size to %sMB", property);
131        mLayerCache.setMaxSize(MB(atof(property)));
132    } else {
133        LOGD("  Using default gradient cache size of %.2fMB", DEFAULT_GRADIENT_CACHE_SIZE);
134    }
135
136    mDrawColorProgram = new DrawColorProgram;
137    mDrawTextureProgram = new DrawTextureProgram;
138    mDrawTextProgram = new DrawTextProgram;
139    mDrawLinearGradientProgram = new DrawLinearGradientProgram;
140    mCurrentProgram = mDrawTextureProgram;
141
142    mShader = kShaderNone;
143    mShaderTileX = GL_CLAMP_TO_EDGE;
144    mShaderTileY = GL_CLAMP_TO_EDGE;
145    mShaderMatrix = NULL;
146    mShaderBitmap = NULL;
147
148    mLastTexture = 0;
149
150    memcpy(mDrawTextureVertices, gDrawTextureVertices, sizeof(gDrawTextureVertices));
151}
152
153OpenGLRenderer::~OpenGLRenderer() {
154    LOGD("Destroy OpenGLRenderer");
155
156    mTextureCache.clear();
157    mLayerCache.clear();
158    mGradientCache.clear();
159    mPatchCache.clear();
160}
161
162///////////////////////////////////////////////////////////////////////////////
163// Setup
164///////////////////////////////////////////////////////////////////////////////
165
166void OpenGLRenderer::setViewport(int width, int height) {
167    glViewport(0, 0, width, height);
168
169    mOrthoMatrix.loadOrtho(0, width, height, 0, -1, 1);
170
171    mWidth = width;
172    mHeight = height;
173    mFirstSnapshot.height = height;
174}
175
176void OpenGLRenderer::prepare() {
177    mSnapshot = &mFirstSnapshot;
178    mSaveCount = 0;
179
180    glDisable(GL_SCISSOR_TEST);
181
182    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
183    glClear(GL_COLOR_BUFFER_BIT);
184
185    glEnable(GL_SCISSOR_TEST);
186    glScissor(0, 0, mWidth, mHeight);
187
188    mSnapshot->clipRect.set(0.0f, 0.0f, mWidth, mHeight);
189}
190
191///////////////////////////////////////////////////////////////////////////////
192// State management
193///////////////////////////////////////////////////////////////////////////////
194
195int OpenGLRenderer::getSaveCount() const {
196    return mSaveCount;
197}
198
199int OpenGLRenderer::save(int flags) {
200    return saveSnapshot();
201}
202
203void OpenGLRenderer::restore() {
204    if (mSaveCount == 0) return;
205
206    if (restoreSnapshot()) {
207        setScissorFromClip();
208    }
209}
210
211void OpenGLRenderer::restoreToCount(int saveCount) {
212    if (saveCount <= 0 || saveCount > mSaveCount) return;
213
214    bool restoreClip = false;
215
216    while (mSaveCount != saveCount - 1) {
217        restoreClip |= restoreSnapshot();
218    }
219
220    if (restoreClip) {
221        setScissorFromClip();
222    }
223}
224
225int OpenGLRenderer::saveSnapshot() {
226    mSnapshot = new Snapshot(mSnapshot);
227    return ++mSaveCount;
228}
229
230bool OpenGLRenderer::restoreSnapshot() {
231    bool restoreClip = mSnapshot->flags & Snapshot::kFlagClipSet;
232    bool restoreLayer = mSnapshot->flags & Snapshot::kFlagIsLayer;
233    bool restoreOrtho = mSnapshot->flags & Snapshot::kFlagDirtyOrtho;
234
235    sp<Snapshot> current = mSnapshot;
236    sp<Snapshot> previous = mSnapshot->previous;
237
238    if (restoreOrtho) {
239        mOrthoMatrix.load(current->orthoMatrix);
240    }
241
242    if (restoreLayer) {
243        composeLayer(current, previous);
244    }
245
246    mSnapshot = previous;
247    mSaveCount--;
248
249    return restoreClip;
250}
251
252void OpenGLRenderer::composeLayer(sp<Snapshot> current, sp<Snapshot> previous) {
253    if (!current->layer) {
254        LOGE("Attempting to compose a layer that does not exist");
255        return;
256    }
257
258    // Unbind current FBO and restore previous one
259    // Most of the time, previous->fbo will be 0 to bind the default buffer
260    glBindFramebuffer(GL_FRAMEBUFFER, previous->fbo);
261
262    // Restore the clip from the previous snapshot
263    const Rect& clip = previous->clipRect;
264    glScissor(clip.left, mHeight - clip.bottom, clip.getWidth(), clip.getHeight());
265
266    Layer* layer = current->layer;
267
268    // Compute the correct texture coordinates for the FBO texture
269    // The texture is currently as big as the window but drawn with
270    // a quad of the appropriate size
271    const Rect& rect = layer->layer;
272
273    drawTextureRect(rect.left, rect.top, rect.right, rect.bottom,
274            layer->texture, layer->alpha, layer->mode, layer->blend);
275
276    LayerSize size(rect.getWidth(), rect.getHeight());
277    // Failing to add the layer to the cache should happen only if the
278    // layer is too large
279    if (!mLayerCache.put(size, layer)) {
280        LAYER_LOGD("Deleting layer");
281
282        glDeleteFramebuffers(1, &layer->fbo);
283        glDeleteTextures(1, &layer->texture);
284
285        delete layer;
286    }
287}
288
289///////////////////////////////////////////////////////////////////////////////
290// Layers
291///////////////////////////////////////////////////////////////////////////////
292
293int OpenGLRenderer::saveLayer(float left, float top, float right, float bottom,
294        const SkPaint* p, int flags) {
295    int count = saveSnapshot();
296
297    int alpha = 255;
298    SkXfermode::Mode mode;
299
300    if (p) {
301        alpha = p->getAlpha();
302        const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode);
303        if (!isMode) {
304            // Assume SRC_OVER
305            mode = SkXfermode::kSrcOver_Mode;
306        }
307    } else {
308        mode = SkXfermode::kSrcOver_Mode;
309    }
310
311    createLayer(mSnapshot, left, top, right, bottom, alpha, mode, flags);
312
313    return count;
314}
315
316int OpenGLRenderer::saveLayerAlpha(float left, float top, float right, float bottom,
317        int alpha, int flags) {
318    int count = saveSnapshot();
319    createLayer(mSnapshot, left, top, right, bottom, alpha, SkXfermode::kSrcOver_Mode, flags);
320    return count;
321}
322
323bool OpenGLRenderer::createLayer(sp<Snapshot> snapshot, float left, float top,
324        float right, float bottom, int alpha, SkXfermode::Mode mode,int flags) {
325
326    LAYER_LOGD("Requesting layer %fx%f", right - left, bottom - top);
327    LAYER_LOGD("Layer cache size = %d", mLayerCache.getSize());
328
329    GLuint previousFbo = snapshot->previous.get() ? snapshot->previous->fbo : 0;
330    LayerSize size(right - left, bottom - top);
331
332    Layer* layer = mLayerCache.get(size, previousFbo);
333    if (!layer) {
334        return false;
335    }
336
337    glBindFramebuffer(GL_FRAMEBUFFER, layer->fbo);
338
339    // Clear the FBO
340    glDisable(GL_SCISSOR_TEST);
341    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
342    glClear(GL_COLOR_BUFFER_BIT);
343    glEnable(GL_SCISSOR_TEST);
344
345    // Save the layer in the snapshot
346    snapshot->flags |= Snapshot::kFlagIsLayer;
347    layer->mode = mode;
348    layer->alpha = alpha / 255.0f;
349    layer->layer.set(left, top, right, bottom);
350
351    snapshot->layer = layer;
352    snapshot->fbo = layer->fbo;
353
354    // Creates a new snapshot to draw into the FBO
355    saveSnapshot();
356    // TODO: This doesn't preserve other transformations (check Skia first)
357    mSnapshot->transform.loadTranslate(-left, -top, 0.0f);
358    mSnapshot->setClip(0.0f, 0.0f, right - left, bottom - top);
359    mSnapshot->height = bottom - top;
360    setScissorFromClip();
361
362    mSnapshot->flags = Snapshot::kFlagDirtyOrtho | Snapshot::kFlagClipSet;
363    mSnapshot->orthoMatrix.load(mOrthoMatrix);
364
365    // Change the ortho projection
366    mOrthoMatrix.loadOrtho(0.0f, right - left, bottom - top, 0.0f, 0.0f, 1.0f);
367
368    return true;
369}
370
371///////////////////////////////////////////////////////////////////////////////
372// Transforms
373///////////////////////////////////////////////////////////////////////////////
374
375void OpenGLRenderer::translate(float dx, float dy) {
376    mSnapshot->transform.translate(dx, dy, 0.0f);
377}
378
379void OpenGLRenderer::rotate(float degrees) {
380    mSnapshot->transform.rotate(degrees, 0.0f, 0.0f, 1.0f);
381}
382
383void OpenGLRenderer::scale(float sx, float sy) {
384    mSnapshot->transform.scale(sx, sy, 1.0f);
385}
386
387void OpenGLRenderer::setMatrix(SkMatrix* matrix) {
388    mSnapshot->transform.load(*matrix);
389}
390
391void OpenGLRenderer::getMatrix(SkMatrix* matrix) {
392    mSnapshot->transform.copyTo(*matrix);
393}
394
395void OpenGLRenderer::concatMatrix(SkMatrix* matrix) {
396    mat4 m(*matrix);
397    mSnapshot->transform.multiply(m);
398}
399
400///////////////////////////////////////////////////////////////////////////////
401// Clipping
402///////////////////////////////////////////////////////////////////////////////
403
404void OpenGLRenderer::setScissorFromClip() {
405    const Rect& clip = mSnapshot->clipRect;
406    glScissor(clip.left, mSnapshot->height - clip.bottom, clip.getWidth(), clip.getHeight());
407}
408
409const Rect& OpenGLRenderer::getClipBounds() {
410    return mSnapshot->getLocalClip();
411}
412
413bool OpenGLRenderer::quickReject(float left, float top, float right, float bottom) {
414    Rect r(left, top, right, bottom);
415    mSnapshot->transform.mapRect(r);
416    return !mSnapshot->clipRect.intersects(r);
417}
418
419bool OpenGLRenderer::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {
420    bool clipped = mSnapshot->clip(left, top, right, bottom, op);
421    if (clipped) {
422        setScissorFromClip();
423    }
424    return !mSnapshot->clipRect.isEmpty();
425}
426
427///////////////////////////////////////////////////////////////////////////////
428// Drawing
429///////////////////////////////////////////////////////////////////////////////
430
431void OpenGLRenderer::drawBitmap(SkBitmap* bitmap, float left, float top, const SkPaint* paint) {
432    const float right = left + bitmap->width();
433    const float bottom = top + bitmap->height();
434
435    if (quickReject(left, top, right, bottom)) {
436        return;
437    }
438
439    const Texture* texture = mTextureCache.get(bitmap);
440    drawTextureRect(left, top, right, bottom, texture, paint);
441}
442
443void OpenGLRenderer::drawBitmap(SkBitmap* bitmap, const SkMatrix* matrix, const SkPaint* paint) {
444    Rect r(0.0f, 0.0f, bitmap->width(), bitmap->height());
445    const mat4 transform(*matrix);
446    transform.mapRect(r);
447
448    if (quickReject(r.left, r.top, r.right, r.bottom)) {
449        return;
450    }
451
452    const Texture* texture = mTextureCache.get(bitmap);
453    drawTextureRect(r.left, r.top, r.right, r.bottom, texture, paint);
454}
455
456void OpenGLRenderer::drawBitmap(SkBitmap* bitmap,
457         float srcLeft, float srcTop, float srcRight, float srcBottom,
458         float dstLeft, float dstTop, float dstRight, float dstBottom,
459         const SkPaint* paint) {
460    if (quickReject(dstLeft, dstTop, dstRight, dstBottom)) {
461        return;
462    }
463
464    const Texture* texture = mTextureCache.get(bitmap);
465
466    const float width = texture->width;
467    const float height = texture->height;
468
469    const float u1 = srcLeft / width;
470    const float v1 = srcTop / height;
471    const float u2 = srcRight / width;
472    const float v2 = srcBottom / height;
473
474    resetDrawTextureTexCoords(u1, v1, u2, v2);
475
476    drawTextureRect(dstLeft, dstTop, dstRight, dstBottom, texture, paint);
477
478    resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
479}
480
481void OpenGLRenderer::drawPatch(SkBitmap* bitmap, Res_png_9patch* patch,
482        float left, float top, float right, float bottom, const SkPaint* paint) {
483    if (quickReject(left, top, right, bottom)) {
484        return;
485    }
486
487    const Texture* texture = mTextureCache.get(bitmap);
488
489    int alpha;
490    SkXfermode::Mode mode;
491    getAlphaAndMode(paint, &alpha, &mode);
492
493    Patch* mesh = mPatchCache.get(patch);
494    mesh->updateVertices(bitmap, left, top, right, bottom,
495            &patch->xDivs[0], &patch->yDivs[0], patch->numXDivs, patch->numYDivs);
496
497    // Specify right and bottom as +1.0f from left/top to prevent scaling since the
498    // patch mesh already defines the final size
499    drawTextureMesh(left, top, left + 1.0f, top + 1.0f, texture->id, alpha / 255.0f,
500            mode, texture->blend, &mesh->vertices[0].position[0],
501            &mesh->vertices[0].texture[0], mesh->indices, mesh->indicesCount);
502}
503
504void OpenGLRenderer::drawColor(int color, SkXfermode::Mode mode) {
505    const Rect& clip = mSnapshot->clipRect;
506    drawColorRect(clip.left, clip.top, clip.right, clip.bottom, color, mode, true);
507}
508
509void OpenGLRenderer::drawRect(float left, float top, float right, float bottom, const SkPaint* p) {
510    if (quickReject(left, top, right, bottom)) {
511        return;
512    }
513
514    SkXfermode::Mode mode;
515
516    const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode);
517    if (!isMode) {
518        // Assume SRC_OVER
519        mode = SkXfermode::kSrcOver_Mode;
520    }
521
522    // Skia draws using the color's alpha channel if < 255
523    // Otherwise, it uses the paint's alpha
524    int color = p->getColor();
525    if (((color >> 24) & 0xff) == 255) {
526        color |= p->getAlpha() << 24;
527    }
528
529    drawColorRect(left, top, right, bottom, color, mode);
530}
531
532void OpenGLRenderer::drawText(const char* text, int count, float x, float y, SkPaint* paint) {
533    // TODO: Support paint's text alignments, proper clipping
534    if (quickReject(x, y, x + 1, y +1)) {
535        return;
536    }
537
538    int alpha;
539    SkXfermode::Mode mode;
540    getAlphaAndMode(paint, &alpha, &mode);
541
542    uint32_t color = paint->getColor();
543    const GLfloat a = alpha / 255.0f;
544    const GLfloat r = a * ((color >> 16) & 0xFF) / 255.0f;
545    const GLfloat g = a * ((color >>  8) & 0xFF) / 255.0f;
546    const GLfloat b = a * ((color      ) & 0xFF) / 255.0f;
547
548    mModelView.loadIdentity();
549
550    useProgram(mDrawTextProgram);
551    mDrawTextProgram->set(mOrthoMatrix, mModelView, mSnapshot->transform);
552
553    chooseBlending(true, mode);
554    bindTexture(mFontRenderer.getTexture(), GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE);
555
556    // Always premultiplied
557    glUniform4f(mDrawTextProgram->color, r, g, b, a);
558
559    mFontRenderer.setFont(SkTypeface::UniqueID(paint->getTypeface()), paint->getTextSize());
560    mFontRenderer.renderText(paint, text, count, 0, count, x, y);
561
562    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
563}
564
565///////////////////////////////////////////////////////////////////////////////
566// Shaders
567///////////////////////////////////////////////////////////////////////////////
568
569void OpenGLRenderer::resetShader() {
570    mShader = OpenGLRenderer::kShaderNone;
571    mShaderKey = NULL;
572    mShaderBlend = false;
573    mShaderTileX = GL_CLAMP_TO_EDGE;
574    mShaderTileY = GL_CLAMP_TO_EDGE;
575}
576
577void OpenGLRenderer::setupBitmapShader(SkBitmap* bitmap, SkShader::TileMode tileX,
578        SkShader::TileMode tileY, SkMatrix* matrix, bool hasAlpha) {
579    mShader = OpenGLRenderer::kShaderBitmap;
580    mShaderBlend = hasAlpha;
581    mShaderBitmap = bitmap;
582    mShaderTileX = gTileModes[tileX];
583    mShaderTileY = gTileModes[tileY];
584    mShaderMatrix = matrix;
585}
586
587void OpenGLRenderer::setupLinearGradientShader(SkShader* shader, float* bounds, uint32_t* colors,
588        float* positions, int count, SkShader::TileMode tileMode, SkMatrix* matrix,
589        bool hasAlpha) {
590    // TODO: We should use a struct to describe each shader
591    mShader = OpenGLRenderer::kShaderLinearGradient;
592    mShaderKey = shader;
593    mShaderBlend = hasAlpha;
594    mShaderTileX = gTileModes[tileMode];
595    mShaderTileY = gTileModes[tileMode];
596    mShaderMatrix = matrix;
597    mShaderBounds = bounds;
598    mShaderColors = colors;
599    mShaderPositions = positions;
600    mShaderCount = count;
601}
602
603///////////////////////////////////////////////////////////////////////////////
604// Drawing implementation
605///////////////////////////////////////////////////////////////////////////////
606
607void OpenGLRenderer::drawColorRect(float left, float top, float right, float bottom,
608        int color, SkXfermode::Mode mode, bool ignoreTransform) {
609    // If a shader is set, preserve only the alpha
610    if (mShader != kShaderNone) {
611        color |= 0x00ffffff;
612    }
613
614    // Render using pre-multiplied alpha
615    const int alpha = (color >> 24) & 0xFF;
616    const GLfloat a = alpha / 255.0f;
617
618    switch (mShader) {
619        case OpenGLRenderer::kShaderBitmap:
620            drawBitmapShader(left, top, right, bottom, a, mode);
621            return;
622        case OpenGLRenderer::kShaderLinearGradient:
623            drawLinearGradientShader(left, top, right, bottom, a, mode);
624            return;
625        default:
626            break;
627    }
628
629    const GLfloat r = a * ((color >> 16) & 0xFF) / 255.0f;
630    const GLfloat g = a * ((color >>  8) & 0xFF) / 255.0f;
631    const GLfloat b = a * ((color      ) & 0xFF) / 255.0f;
632
633    // Pre-multiplication happens when setting the shader color
634    chooseBlending(alpha < 255 || mShaderBlend, mode);
635
636    mModelView.loadTranslate(left, top, 0.0f);
637    mModelView.scale(right - left, bottom - top, 1.0f);
638
639    if (!useProgram(mDrawColorProgram)) {
640        const GLvoid* p = &gDrawColorVertices[0].position[0];
641        glVertexAttribPointer(mDrawColorProgram->position, 2, GL_FLOAT, GL_FALSE,
642                gDrawColorVertexStride, p);
643    }
644
645    if (!ignoreTransform) {
646        mDrawColorProgram->set(mOrthoMatrix, mModelView, mSnapshot->transform);
647    } else {
648        mat4 identity;
649        mDrawColorProgram->set(mOrthoMatrix, mModelView, identity);
650    }
651
652    glUniform4f(mDrawColorProgram->color, r, g, b, a);
653
654    glDrawArrays(GL_TRIANGLE_STRIP, 0, gDrawColorVertexCount);
655}
656
657void OpenGLRenderer::drawLinearGradientShader(float left, float top, float right, float bottom,
658        float alpha, SkXfermode::Mode mode) {
659    Texture* texture = mGradientCache.get(mShaderKey);
660    if (!texture) {
661        SkShader::TileMode tileMode = SkShader::kClamp_TileMode;
662        switch (mShaderTileX) {
663            case GL_REPEAT:
664                tileMode = SkShader::kRepeat_TileMode;
665                break;
666            case GL_MIRRORED_REPEAT:
667                tileMode = SkShader::kMirror_TileMode;
668                break;
669        }
670
671        texture = mGradientCache.addLinearGradient(mShaderKey, mShaderBounds, mShaderColors,
672                mShaderPositions, mShaderCount, tileMode);
673    }
674
675    mModelView.loadTranslate(left, top, 0.0f);
676    mModelView.scale(right - left, bottom - top, 1.0f);
677
678    useProgram(mDrawLinearGradientProgram);
679    mDrawLinearGradientProgram->set(mOrthoMatrix, mModelView, mSnapshot->transform);
680
681    chooseBlending(mShaderBlend || alpha < 1.0f, mode);
682    bindTexture(texture->id, mShaderTileX, mShaderTileY);
683
684    Rect start(mShaderBounds[0], mShaderBounds[1], mShaderBounds[2], mShaderBounds[3]);
685    if (mShaderMatrix) {
686        mat4 shaderMatrix(*mShaderMatrix);
687        shaderMatrix.mapRect(start);
688    }
689    mSnapshot->transform.mapRect(start);
690
691    const float gradientX = start.right - start.left;
692    const float gradientY = start.bottom - start.top;
693
694    mat4 screenSpace(mSnapshot->transform);
695    screenSpace.multiply(mModelView);
696
697    // Always premultiplied
698    glUniform4f(mDrawLinearGradientProgram->color, alpha, alpha, alpha, alpha);
699    glUniform2f(mDrawLinearGradientProgram->start, start.left, start.top);
700    glUniform2f(mDrawLinearGradientProgram->gradient, gradientX, gradientY);
701    glUniform1f(mDrawLinearGradientProgram->gradientLength,
702            1.0f / (gradientX * gradientX + gradientY * gradientY));
703    glUniformMatrix4fv(mDrawLinearGradientProgram->screenSpace, 1, GL_FALSE,
704            &screenSpace.data[0]);
705
706    glVertexAttribPointer(mDrawLinearGradientProgram->position, 2, GL_FLOAT, GL_FALSE,
707            gDrawTextureVertexStride, &mDrawTextureVertices[0].position[0]);
708
709    glDrawArrays(GL_TRIANGLE_STRIP, 0, gDrawTextureVertexCount);
710}
711
712void OpenGLRenderer::drawBitmapShader(float left, float top, float right, float bottom,
713        float alpha, SkXfermode::Mode mode) {
714    const Texture* texture = mTextureCache.get(mShaderBitmap);
715
716    const float width = texture->width;
717    const float height = texture->height;
718
719    // This could be done in the vertex shader but we have only 4 vertices
720    float u1 = 0.0f;
721    float v1 = 0.0f;
722    float u2 = right - left;
723    float v2 = bottom - top;
724
725    // TODO: If the texture is not pow, use a shader to support repeat/mirror
726    if (mShaderMatrix) {
727        SkMatrix inverse;
728        mShaderMatrix->invert(&inverse);
729        mat4 m(inverse);
730        Rect r(u1, v1, u2, v2);
731        m.mapRect(r);
732
733        u1 = r.left;
734        u2 = r.right;
735        v1 = r.top;
736        v2 = r.bottom;
737    }
738
739    u1 /= width;
740    u2 /= width;
741    v1 /= height;
742    v2 /= height;
743
744    resetDrawTextureTexCoords(u1, v1, u2, v2);
745
746    drawTextureMesh(left, top, right, bottom, texture->id, alpha, mode, texture->blend,
747            &mDrawTextureVertices[0].position[0], &mDrawTextureVertices[0].texture[0], NULL);
748
749    resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
750}
751
752void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom,
753        const Texture* texture, const SkPaint* paint) {
754    int alpha;
755    SkXfermode::Mode mode;
756    getAlphaAndMode(paint, &alpha, &mode);
757
758    drawTextureMesh(left, top, right, bottom, texture->id, alpha / 255.0f, mode, texture->blend,
759            &mDrawTextureVertices[0].position[0], &mDrawTextureVertices[0].texture[0], NULL);
760}
761
762void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom,
763        GLuint texture, float alpha, SkXfermode::Mode mode, bool blend) {
764    drawTextureMesh(left, top, right, bottom, texture, alpha, mode, blend,
765            &mDrawTextureVertices[0].position[0], &mDrawTextureVertices[0].texture[0], NULL);
766}
767
768void OpenGLRenderer::drawTextureMesh(float left, float top, float right, float bottom,
769        GLuint texture, float alpha, SkXfermode::Mode mode, bool blend,
770        GLvoid* vertices, GLvoid* texCoords, GLvoid* indices, GLsizei elementsCount) {
771    mModelView.loadTranslate(left, top, 0.0f);
772    mModelView.scale(right - left, bottom - top, 1.0f);
773
774    useProgram(mDrawTextureProgram);
775    mDrawTextureProgram->set(mOrthoMatrix, mModelView, mSnapshot->transform);
776
777    chooseBlending(blend || alpha < 1.0f, mode);
778    bindTexture(texture, mShaderTileX, mShaderTileY);
779
780    // Always premultiplied
781    glUniform4f(mDrawTextureProgram->color, alpha, alpha, alpha, alpha);
782
783    glVertexAttribPointer(mDrawTextureProgram->position, 2, GL_FLOAT, GL_FALSE,
784            gDrawTextureVertexStride, vertices);
785    glVertexAttribPointer(mDrawTextureProgram->texCoords, 2, GL_FLOAT, GL_FALSE,
786            gDrawTextureVertexStride, texCoords);
787
788    if (!indices) {
789        glDrawArrays(GL_TRIANGLE_STRIP, 0, gDrawTextureVertexCount);
790    } else {
791        glDrawElements(GL_TRIANGLES, elementsCount, GL_UNSIGNED_SHORT, indices);
792    }
793}
794
795void OpenGLRenderer::chooseBlending(bool blend, SkXfermode::Mode mode, bool isPremultiplied) {
796    // In theory we should not blend if the mode is Src, but it's rare enough
797    // that it's not worth it
798    blend = blend || mode != SkXfermode::kSrcOver_Mode;
799    if (blend) {
800        if (!mBlend) {
801            glEnable(GL_BLEND);
802        }
803
804        GLenum sourceMode = gBlends[mode].src;
805        GLenum destMode = gBlends[mode].dst;
806        if (!isPremultiplied && sourceMode == GL_ONE) {
807            sourceMode = GL_SRC_ALPHA;
808        }
809
810        if (sourceMode != mLastSrcMode || destMode != mLastDstMode) {
811            glBlendFunc(sourceMode, destMode);
812            mLastSrcMode = sourceMode;
813            mLastDstMode = destMode;
814        }
815    } else if (mBlend) {
816        glDisable(GL_BLEND);
817    }
818    mBlend = blend;
819}
820
821bool OpenGLRenderer::useProgram(const sp<Program>& program) {
822    if (!program->isInUse()) {
823        mCurrentProgram->remove();
824        program->use();
825        mCurrentProgram = program;
826        return false;
827    }
828    return true;
829}
830
831void OpenGLRenderer::resetDrawTextureTexCoords(float u1, float v1, float u2, float v2) {
832    TextureVertex* v = &mDrawTextureVertices[0];
833    TextureVertex::setUV(v++, u1, v1);
834    TextureVertex::setUV(v++, u2, v1);
835    TextureVertex::setUV(v++, u1, v2);
836    TextureVertex::setUV(v++, u2, v2);
837}
838
839void OpenGLRenderer::getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode) {
840    if (paint) {
841        const bool isMode = SkXfermode::IsMode(paint->getXfermode(), mode);
842        if (!isMode) {
843            // Assume SRC_OVER
844            *mode = SkXfermode::kSrcOver_Mode;
845        }
846
847        // Skia draws using the color's alpha channel if < 255
848        // Otherwise, it uses the paint's alpha
849        int color = paint->getColor();
850        *alpha = (color >> 24) & 0xFF;
851        if (*alpha == 255) {
852            *alpha = paint->getAlpha();
853        }
854    } else {
855        *mode = SkXfermode::kSrcOver_Mode;
856        *alpha = 255;
857    }
858}
859
860void OpenGLRenderer::bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT) {
861    if (texture != mLastTexture) {
862        glBindTexture(GL_TEXTURE_2D, texture);
863        mLastTexture = texture;
864    }
865    // TODO: Don't set the texture parameters every time
866    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrapS);
867    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrapT);
868}
869
870}; // namespace uirenderer
871}; // namespace android
872