OpenGLRenderer.cpp revision 121e2242565d5f09ad83a2d33ecd2225838802c5
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 25#include <cutils/properties.h> 26#include <utils/Log.h> 27 28#include "OpenGLRenderer.h" 29 30namespace android { 31namespace uirenderer { 32 33/////////////////////////////////////////////////////////////////////////////// 34// Defines 35/////////////////////////////////////////////////////////////////////////////// 36 37// These properties are defined in mega-bytes 38#define PROPERTY_TEXTURE_CACHE_SIZE "ro.hwui.texture_cache_size" 39#define PROPERTY_LAYER_CACHE_SIZE "ro.hwui.layer_cache_size" 40 41// Converts a number of mega-bytes into bytes 42#define MB(s) s * 1024 * 1024 43 44#define DEFAULT_TEXTURE_CACHE_SIZE MB(20) 45#define DEFAULT_LAYER_CACHE_SIZE MB(10) 46 47#define SV(x, y) { { x, y } } 48#define FV(x, y, u, v) { { x, y }, { u, v } } 49 50/////////////////////////////////////////////////////////////////////////////// 51// Globals 52/////////////////////////////////////////////////////////////////////////////// 53 54static const SimpleVertex gDrawColorVertices[] = { 55 SV(0.0f, 0.0f), 56 SV(1.0f, 0.0f), 57 SV(0.0f, 1.0f), 58 SV(1.0f, 1.0f) 59}; 60static const GLsizei gDrawColorVertexStride = sizeof(SimpleVertex); 61static const GLsizei gDrawColorVertexCount = 4; 62 63// This array is never used directly but used as a memcpy source in the 64// OpenGLRenderer constructor 65static const TextureVertex gDrawTextureVertices[] = { 66 FV(0.0f, 0.0f, 0.0f, 0.0f), 67 FV(1.0f, 0.0f, 1.0f, 0.0f), 68 FV(0.0f, 1.0f, 0.0f, 1.0f), 69 FV(1.0f, 1.0f, 1.0f, 1.0f) 70}; 71static const GLsizei gDrawTextureVertexStride = sizeof(TextureVertex); 72static const GLsizei gDrawTextureVertexCount = 4; 73 74// In this array, the index of each Blender equals the value of the first 75// entry. For instance, gBlends[1] == gBlends[SkXfermode::kSrc_Mode] 76static const Blender gBlends[] = { 77 { SkXfermode::kClear_Mode, GL_ZERO, GL_ZERO }, 78 { SkXfermode::kSrc_Mode, GL_ONE, GL_ZERO }, 79 { SkXfermode::kDst_Mode, GL_ZERO, GL_ONE }, 80 { SkXfermode::kSrcOver_Mode, GL_ONE, GL_ONE_MINUS_SRC_ALPHA }, 81 { SkXfermode::kDstOver_Mode, GL_ONE_MINUS_DST_ALPHA, GL_ONE }, 82 { SkXfermode::kSrcIn_Mode, GL_DST_ALPHA, GL_ZERO }, 83 { SkXfermode::kDstIn_Mode, GL_ZERO, GL_SRC_ALPHA }, 84 { SkXfermode::kSrcOut_Mode, GL_ONE_MINUS_DST_ALPHA, GL_ZERO }, 85 { SkXfermode::kDstOut_Mode, GL_ZERO, GL_ONE_MINUS_SRC_ALPHA }, 86 { SkXfermode::kSrcATop_Mode, GL_DST_ALPHA, GL_ONE_MINUS_SRC_ALPHA }, 87 { SkXfermode::kDstATop_Mode, GL_ONE_MINUS_DST_ALPHA, GL_SRC_ALPHA }, 88 { SkXfermode::kXor_Mode, GL_ONE_MINUS_DST_ALPHA, GL_ONE_MINUS_SRC_ALPHA } 89}; 90 91/////////////////////////////////////////////////////////////////////////////// 92// Constructors/destructor 93/////////////////////////////////////////////////////////////////////////////// 94 95OpenGLRenderer::OpenGLRenderer(): mTextureCache(DEFAULT_TEXTURE_CACHE_SIZE) { 96 LOGD("Create OpenGLRenderer"); 97 98 char property[PROPERTY_VALUE_MAX]; 99 if (property_get(PROPERTY_TEXTURE_CACHE_SIZE, property, NULL) > 0) { 100 mTextureCache.setMaxSize(MB(atoi(property))); 101 } 102 103 mDrawColorShader = new DrawColorProgram; 104 mDrawTextureShader = new DrawTextureProgram; 105 106 memcpy(mDrawTextureVertices, gDrawTextureVertices, sizeof(gDrawTextureVertices)); 107} 108 109OpenGLRenderer::~OpenGLRenderer() { 110 LOGD("Destroy OpenGLRenderer"); 111 112 mTextureCache.clear(); 113} 114 115/////////////////////////////////////////////////////////////////////////////// 116// Setup 117/////////////////////////////////////////////////////////////////////////////// 118 119void OpenGLRenderer::setViewport(int width, int height) { 120 glViewport(0, 0, width, height); 121 122 mat4 ortho; 123 ortho.loadOrtho(0, width, height, 0, -1, 1); 124 ortho.copyTo(mOrthoMatrix); 125 126 mWidth = width; 127 mHeight = height; 128 mFirstSnapshot.height = height; 129} 130 131void OpenGLRenderer::prepare() { 132 mSnapshot = &mFirstSnapshot; 133 mSaveCount = 0; 134 135 glDisable(GL_SCISSOR_TEST); 136 137 glClearColor(0.0f, 0.0f, 0.0f, 0.0f); 138 glClear(GL_COLOR_BUFFER_BIT); 139 140 glEnable(GL_SCISSOR_TEST); 141 glScissor(0, 0, mWidth, mHeight); 142 143 mSnapshot->clipRect.set(0.0f, 0.0f, mWidth, mHeight); 144} 145 146/////////////////////////////////////////////////////////////////////////////// 147// State management 148/////////////////////////////////////////////////////////////////////////////// 149 150int OpenGLRenderer::getSaveCount() const { 151 return mSaveCount; 152} 153 154int OpenGLRenderer::save(int flags) { 155 return saveSnapshot(); 156} 157 158void OpenGLRenderer::restore() { 159 if (mSaveCount == 0) return; 160 161 if (restoreSnapshot()) { 162 setScissorFromClip(); 163 } 164} 165 166void OpenGLRenderer::restoreToCount(int saveCount) { 167 if (saveCount <= 0 || saveCount > mSaveCount) return; 168 169 bool restoreClip = false; 170 171 while (mSaveCount != saveCount - 1) { 172 restoreClip |= restoreSnapshot(); 173 } 174 175 if (restoreClip) { 176 setScissorFromClip(); 177 } 178} 179 180int OpenGLRenderer::saveSnapshot() { 181 mSnapshot = new Snapshot(mSnapshot); 182 return ++mSaveCount; 183} 184 185bool OpenGLRenderer::restoreSnapshot() { 186 bool restoreClip = mSnapshot->flags & Snapshot::kFlagClipSet; 187 bool restoreLayer = mSnapshot->flags & Snapshot::kFlagIsLayer; 188 bool restoreOrtho = mSnapshot->flags & Snapshot::kFlagDirtyOrtho; 189 190 sp<Snapshot> current = mSnapshot; 191 sp<Snapshot> previous = mSnapshot->previous; 192 193 if (restoreOrtho) { 194 memcpy(mOrthoMatrix, current->orthoMatrix, sizeof(mOrthoMatrix)); 195 } 196 197 if (restoreLayer) { 198 composeLayer(current, previous); 199 } 200 201 mSnapshot = previous; 202 mSaveCount--; 203 204 return restoreClip; 205} 206 207void OpenGLRenderer::composeLayer(sp<Snapshot> current, sp<Snapshot> previous) { 208 // Unbind current FBO and restore previous one 209 // Most of the time, previous->fbo will be 0 to bind the default buffer 210 glBindFramebuffer(GL_FRAMEBUFFER, previous->fbo); 211 212 // Restore the clip from the previous snapshot 213 const Rect& clip = previous->getMappedClip(); 214 glScissor(clip.left, mHeight - clip.bottom, clip.getWidth(), clip.getHeight()); 215 216 // Compute the correct texture coordinates for the FBO texture 217 // The texture is currently as big as the window but drawn with 218 // a quad of the appropriate size 219 const Rect& layer = current->layer; 220 221 drawTextureRect(layer.left, layer.top, layer.right, layer.bottom, 222 current->texture, current->alpha, current->mode, true, true); 223 224 // TODO Don't delete these things, but cache them 225 glDeleteFramebuffers(1, ¤t->fbo); 226 glDeleteTextures(1, ¤t->texture); 227} 228 229/////////////////////////////////////////////////////////////////////////////// 230// Layers 231/////////////////////////////////////////////////////////////////////////////// 232 233int OpenGLRenderer::saveLayer(float left, float top, float right, float bottom, 234 const SkPaint* p, int flags) { 235 int count = saveSnapshot(); 236 237 int alpha = 255; 238 SkXfermode::Mode mode; 239 240 if (p) { 241 alpha = p->getAlpha(); 242 const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode); 243 if (!isMode) { 244 // Assume SRC_OVER 245 mode = SkXfermode::kSrcOver_Mode; 246 } 247 } else { 248 mode = SkXfermode::kSrcOver_Mode; 249 } 250 251 createLayer(mSnapshot, left, top, right, bottom, alpha, mode, flags); 252 253 return count; 254} 255 256int OpenGLRenderer::saveLayerAlpha(float left, float top, float right, float bottom, 257 int alpha, int flags) { 258 int count = saveSnapshot(); 259 createLayer(mSnapshot, left, top, right, bottom, alpha, SkXfermode::kSrcOver_Mode, flags); 260 return count; 261} 262 263bool OpenGLRenderer::createLayer(sp<Snapshot> snapshot, float left, float top, 264 float right, float bottom, int alpha, SkXfermode::Mode mode,int flags) { 265 // Generate the FBO and attach the texture 266 glGenFramebuffers(1, &snapshot->fbo); 267 glBindFramebuffer(GL_FRAMEBUFFER, snapshot->fbo); 268 269 // Generate the texture in which the FBO will draw 270 glGenTextures(1, &snapshot->texture); 271 glBindTexture(GL_TEXTURE_2D, snapshot->texture); 272 273 // The FBO will not be scaled, so we can use lower quality filtering 274 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); 275 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); 276 277 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); 278 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); 279 280 // TODO VERY IMPORTANT: Fix TextView to not call saveLayer() all the time 281 // TODO Use an FBO cache 282 283 const GLsizei width = right - left; 284 const GLsizei height = bottom - top; 285 286 const GLint format = (flags & SkCanvas::kHasAlphaLayer_SaveFlag) ? GL_RGBA : GL_RGB; 287 glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, NULL); 288 glBindTexture(GL_TEXTURE_2D, 0); 289 290 // Bind texture to FBO 291 glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 292 snapshot->texture, 0); 293 294 GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER); 295 if (status != GL_FRAMEBUFFER_COMPLETE) { 296 LOGD("Framebuffer incomplete (GL error code 0x%x)", status); 297 298 glDeleteFramebuffers(1, &snapshot->fbo); 299 glDeleteTextures(1, &snapshot->texture); 300 301 return false; 302 } 303 304 // Clear the FBO 305 glDisable(GL_SCISSOR_TEST); 306 glClearColor(0.0f, 0.0f, 0.0f, 0.0f); 307 glClear(GL_COLOR_BUFFER_BIT); 308 glEnable(GL_SCISSOR_TEST); 309 310 snapshot->flags |= Snapshot::kFlagIsLayer; 311 snapshot->mode = mode; 312 snapshot->alpha = alpha / 255.0f; 313 snapshot->layer.set(left, top, right, bottom); 314 315 // Creates a new snapshot to draw into the FBO 316 saveSnapshot(); 317 // TODO: This doesn't preserve other transformations (check Skia first) 318 mSnapshot->transform.loadTranslate(-left, -top, 0.0f); 319 mSnapshot->clipRect.set(left, top, right, bottom); 320 mSnapshot->height = bottom - top; 321 setScissorFromClip(); 322 323 mSnapshot->flags = Snapshot::kFlagDirtyTransform | Snapshot::kFlagDirtyOrtho | 324 Snapshot::kFlagClipSet; 325 memcpy(mSnapshot->orthoMatrix, mOrthoMatrix, sizeof(mOrthoMatrix)); 326 327 // Change the ortho projection 328 mat4 ortho; 329 ortho.loadOrtho(0.0f, right - left, bottom - top, 0.0f, 0.0f, 1.0f); 330 ortho.copyTo(mOrthoMatrix); 331 332 return true; 333} 334 335/////////////////////////////////////////////////////////////////////////////// 336// Transforms 337/////////////////////////////////////////////////////////////////////////////// 338 339void OpenGLRenderer::translate(float dx, float dy) { 340 mSnapshot->transform.translate(dx, dy, 0.0f); 341 mSnapshot->flags |= Snapshot::kFlagDirtyTransform; 342} 343 344void OpenGLRenderer::rotate(float degrees) { 345 mSnapshot->transform.rotate(degrees, 0.0f, 0.0f, 1.0f); 346 mSnapshot->flags |= Snapshot::kFlagDirtyTransform; 347} 348 349void OpenGLRenderer::scale(float sx, float sy) { 350 mSnapshot->transform.scale(sx, sy, 1.0f); 351 mSnapshot->flags |= Snapshot::kFlagDirtyTransform; 352} 353 354void OpenGLRenderer::setMatrix(SkMatrix* matrix) { 355 mSnapshot->transform.load(*matrix); 356 mSnapshot->flags |= Snapshot::kFlagDirtyTransform; 357} 358 359void OpenGLRenderer::getMatrix(SkMatrix* matrix) { 360 mSnapshot->transform.copyTo(*matrix); 361} 362 363void OpenGLRenderer::concatMatrix(SkMatrix* matrix) { 364 mat4 m(*matrix); 365 mSnapshot->transform.multiply(m); 366 mSnapshot->flags |= Snapshot::kFlagDirtyTransform; 367} 368 369/////////////////////////////////////////////////////////////////////////////// 370// Clipping 371/////////////////////////////////////////////////////////////////////////////// 372 373void OpenGLRenderer::setScissorFromClip() { 374 const Rect& clip = mSnapshot->getMappedClip(); 375 glScissor(clip.left, mSnapshot->height - clip.bottom, clip.getWidth(), clip.getHeight()); 376} 377 378const Rect& OpenGLRenderer::getClipBounds() { 379 return mSnapshot->clipRect; 380} 381 382bool OpenGLRenderer::quickReject(float left, float top, float right, float bottom) { 383 /* 384 * The documentation of quickReject() indicates that the specified rect 385 * is transformed before being compared to the clip rect. However, the 386 * clip rect is not stored transformed in the snapshot and can thus be 387 * compared directly 388 * 389 * The following code can be used instead to performed a mapped comparison: 390 * 391 * mSnapshot->transform.mapRect(r); 392 * const Rect& clip = mSnapshot->getMappedClip(); 393 * return !clip.intersects(r); 394 */ 395 Rect r(left, top, right, bottom); 396 return !mSnapshot->clipRect.intersects(r); 397} 398 399bool OpenGLRenderer::clipRect(float left, float top, float right, float bottom) { 400 bool clipped = mSnapshot->clipRect.intersect(left, top, right, bottom); 401 if (clipped) { 402 mSnapshot->flags |= Snapshot::kFlagClipSet; 403 setScissorFromClip(); 404 } 405 return clipped; 406} 407 408/////////////////////////////////////////////////////////////////////////////// 409// Drawing 410/////////////////////////////////////////////////////////////////////////////// 411 412void OpenGLRenderer::drawBitmap(SkBitmap* bitmap, float left, float top, const SkPaint* paint) { 413 const Texture* texture = mTextureCache.get(bitmap); 414 LOGD("Texture cache size %d", mTextureCache.getSize()); 415 LOGD(" max size %d", mTextureCache.getMaxSize()); 416 417 int alpha; 418 SkXfermode::Mode mode; 419 getAlphaAndMode(paint, &alpha, &mode); 420 421 drawTextureRect(left, top, left + texture->width, top + texture->height, texture->id, 422 alpha / 255.0f, mode, texture->blend, true); 423} 424 425void OpenGLRenderer::drawBitmap(SkBitmap* bitmap, const SkMatrix* matrix, const SkPaint* paint) { 426 Rect r(0.0f, 0.0f, bitmap->width(), bitmap->height()); 427 const mat4 transform(*matrix); 428 transform.mapRect(r); 429 430 const Texture* texture = mTextureCache.get(bitmap); 431 432 int alpha; 433 SkXfermode::Mode mode; 434 getAlphaAndMode(paint, &alpha, &mode); 435 436 drawTextureRect(r.left, r.top, r.right, r.bottom, texture->id, 437 alpha / 255.0f, mode, texture->blend, true); 438} 439 440void OpenGLRenderer::drawBitmap(SkBitmap* bitmap, 441 float srcLeft, float srcTop, float srcRight, float srcBottom, 442 float dstLeft, float dstTop, float dstRight, float dstBottom, 443 const SkPaint* paint) { 444 const Texture* texture = mTextureCache.get(bitmap); 445 446 int alpha; 447 SkXfermode::Mode mode; 448 getAlphaAndMode(paint, &alpha, &mode); 449 450 const float width = texture->width; 451 const float height = texture->height; 452 453 const float u1 = srcLeft / width; 454 const float v1 = srcTop / height; 455 const float u2 = srcRight / width; 456 const float v2 = srcBottom / height; 457 458 resetDrawTextureTexCoords(u1, v1, u2, v2); 459 460 drawTextureRect(dstLeft, dstTop, dstRight, dstBottom, texture->id, 461 alpha / 255.0f, mode, texture->blend, true); 462 463 resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f); 464} 465 466void OpenGLRenderer::drawColor(int color, SkXfermode::Mode mode) { 467 const Rect& clip = mSnapshot->clipRect; 468 drawColorRect(clip.left, clip.top, clip.right, clip.bottom, color, mode); 469} 470 471void OpenGLRenderer::drawRect(float left, float top, float right, float bottom, const SkPaint* p) { 472 SkXfermode::Mode mode; 473 474 const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode); 475 if (!isMode) { 476 // Assume SRC_OVER 477 mode = SkXfermode::kSrcOver_Mode; 478 } 479 480 // Skia draws using the color's alpha channel if < 255 481 // Otherwise, it uses the paint's alpha 482 int color = p->getColor(); 483 if (((color >> 24) & 0xFF) == 255) { 484 color |= p->getAlpha() << 24; 485 } 486 487 drawColorRect(left, top, right, bottom, color, mode); 488} 489 490void OpenGLRenderer::drawColorRect(float left, float top, float right, float bottom, 491 int color, SkXfermode::Mode mode) { 492 const int alpha = (color >> 24) & 0xFF; 493 const bool blend = alpha < 255 || mode != SkXfermode::kSrcOver_Mode; 494 495 const GLfloat a = alpha / 255.0f; 496 const GLfloat r = ((color >> 16) & 0xFF) / 255.0f; 497 const GLfloat g = ((color >> 8) & 0xFF) / 255.0f; 498 const GLfloat b = ((color ) & 0xFF) / 255.0f; 499 500 if (blend) { 501 glEnable(GL_BLEND); 502 glBlendFunc(gBlends[mode].src, gBlends[mode].dst); 503 } 504 505 mModelView.loadTranslate(left, top, 0.0f); 506 mModelView.scale(right - left, bottom - top, 1.0f); 507 508 mDrawColorShader->use(&mOrthoMatrix[0], &mModelView.data[0], &mSnapshot->transform.data[0]); 509 510 const GLvoid* p = &gDrawColorVertices[0].position[0]; 511 512 glEnableVertexAttribArray(mDrawColorShader->position); 513 glVertexAttribPointer(mDrawColorShader->position, 2, GL_FLOAT, GL_FALSE, 514 gDrawColorVertexStride, p); 515 glVertexAttrib4f(mDrawColorShader->color, r, g, b, a); 516 517 glDrawArrays(GL_TRIANGLE_STRIP, 0, gDrawColorVertexCount); 518 519 glDisableVertexAttribArray(mDrawColorShader->position); 520 521 if (blend) { 522 glDisable(GL_BLEND); 523 } 524} 525 526void OpenGLRenderer::drawTextureRect(float left, float top, float right, float bottom, 527 GLuint texture, float alpha, SkXfermode::Mode mode, bool blend, bool isPremultiplied) { 528 mModelView.loadTranslate(left, top, 0.0f); 529 mModelView.scale(right - left, bottom - top, 1.0f); 530 531 mDrawTextureShader->use(&mOrthoMatrix[0], &mModelView.data[0], &mSnapshot->transform.data[0]); 532 533 if (blend || alpha < 1.0f || mode != SkXfermode::kSrcOver_Mode) { 534 GLenum sourceMode = gBlends[mode].src; 535 if (!isPremultiplied && sourceMode == GL_ONE) { 536 sourceMode = GL_SRC_ALPHA; 537 } 538 539 glEnable(GL_BLEND); 540 glBlendFunc(sourceMode, gBlends[mode].dst); 541 } 542 543 glBindTexture(GL_TEXTURE_2D, texture); 544 545 // TODO handle tiling and filtering here 546 547 glActiveTexture(GL_TEXTURE0); 548 glUniform1i(mDrawTextureShader->sampler, 0); 549 550 const GLvoid* p = &mDrawTextureVertices[0].position[0]; 551 const GLvoid* t = &mDrawTextureVertices[0].texture[0]; 552 553 glEnableVertexAttribArray(mDrawTextureShader->position); 554 glVertexAttribPointer(mDrawTextureShader->position, 2, GL_FLOAT, GL_FALSE, 555 gDrawTextureVertexStride, p); 556 557 glEnableVertexAttribArray(mDrawTextureShader->texCoords); 558 glVertexAttribPointer(mDrawTextureShader->texCoords, 2, GL_FLOAT, GL_FALSE, 559 gDrawTextureVertexStride, t); 560 561 glVertexAttrib4f(mDrawTextureShader->color, 1.0f, 1.0f, 1.0f, alpha); 562 563 glDrawArrays(GL_TRIANGLE_STRIP, 0, gDrawTextureVertexCount); 564 565 glDisableVertexAttribArray(mDrawTextureShader->position); 566 glDisableVertexAttribArray(mDrawTextureShader->texCoords); 567 568 glBindTexture(GL_TEXTURE_2D, 0); 569 glDisable(GL_BLEND); 570} 571 572void OpenGLRenderer::resetDrawTextureTexCoords(float u1, float v1, float u2, float v2) { 573 mDrawTextureVertices[0].texture[0] = u1; 574 mDrawTextureVertices[0].texture[1] = v1; 575 mDrawTextureVertices[1].texture[0] = u2; 576 mDrawTextureVertices[1].texture[1] = v1; 577 mDrawTextureVertices[2].texture[0] = u1; 578 mDrawTextureVertices[2].texture[1] = v2; 579 mDrawTextureVertices[3].texture[0] = u2; 580 mDrawTextureVertices[3].texture[1] = v2; 581} 582 583void OpenGLRenderer::getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode) { 584 if (paint) { 585 const bool isMode = SkXfermode::IsMode(paint->getXfermode(), mode); 586 if (!isMode) { 587 // Assume SRC_OVER 588 *mode = SkXfermode::kSrcOver_Mode; 589 } 590 591 // Skia draws using the color's alpha channel if < 255 592 // Otherwise, it uses the paint's alpha 593 int color = paint->getColor(); 594 *alpha = (color >> 24) & 0xFF; 595 if (*alpha == 255) { 596 *alpha = paint->getAlpha(); 597 } 598 } else { 599 *mode = SkXfermode::kSrcOver_Mode; 600 *alpha = 255; 601 } 602} 603 604}; // namespace uirenderer 605}; // namespace android 606