| Jamie Gennis | 9c183f2 | 2012-12-03 16:44:16 -0800 | [diff] [blame] | 1 | /* | 
|  | 2 | * Copyright (C) 2012 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 |  | 
| Mathias Agopian | 5bbe0ab | 2013-08-14 18:22:02 -0700 | [diff] [blame] | 17 | #include <GLES2/gl2.h> | 
|  | 18 | #include <GLES2/gl2ext.h> | 
|  | 19 |  | 
| Jamie Gennis | 9c183f2 | 2012-12-03 16:44:16 -0800 | [diff] [blame] | 20 | #include <ui/DisplayInfo.h> | 
|  | 21 | #include <gui/SurfaceComposerClient.h> | 
|  | 22 |  | 
|  | 23 | #include "GLHelper.h" | 
|  | 24 |  | 
|  | 25 | namespace android { | 
|  | 26 |  | 
|  | 27 | GLHelper::GLHelper() : | 
| Dan Stoza | 70982a5 | 2016-01-11 23:40:44 +0000 | [diff] [blame] | 28 | mGraphicBufferAlloc(new GraphicBufferAlloc()), | 
| Jamie Gennis | 9c183f2 | 2012-12-03 16:44:16 -0800 | [diff] [blame] | 29 | mDisplay(EGL_NO_DISPLAY), | 
|  | 30 | mContext(EGL_NO_CONTEXT), | 
|  | 31 | mDummySurface(EGL_NO_SURFACE), | 
|  | 32 | mConfig(0), | 
|  | 33 | mShaderPrograms(NULL), | 
|  | 34 | mDitherTexture(0) { | 
|  | 35 | } | 
|  | 36 |  | 
|  | 37 | GLHelper::~GLHelper() { | 
|  | 38 | } | 
|  | 39 |  | 
|  | 40 | bool GLHelper::setUp(const ShaderDesc* shaderDescs, size_t numShaders) { | 
|  | 41 | bool result; | 
|  | 42 |  | 
|  | 43 | mDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY); | 
|  | 44 | if (mDisplay == EGL_NO_DISPLAY) { | 
|  | 45 | fprintf(stderr, "eglGetDisplay error: %#x\n", eglGetError()); | 
|  | 46 | return false; | 
|  | 47 | } | 
|  | 48 |  | 
|  | 49 | EGLint majorVersion; | 
|  | 50 | EGLint minorVersion; | 
|  | 51 | result = eglInitialize(mDisplay, &majorVersion, &minorVersion); | 
|  | 52 | if (result != EGL_TRUE) { | 
|  | 53 | fprintf(stderr, "eglInitialize error: %#x\n", eglGetError()); | 
|  | 54 | return false; | 
|  | 55 | } | 
|  | 56 |  | 
|  | 57 | EGLint numConfigs = 0; | 
|  | 58 | EGLint configAttribs[] = { | 
|  | 59 | EGL_SURFACE_TYPE, EGL_WINDOW_BIT, | 
|  | 60 | EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT, | 
|  | 61 | EGL_RED_SIZE, 8, | 
|  | 62 | EGL_GREEN_SIZE, 8, | 
|  | 63 | EGL_BLUE_SIZE, 8, | 
|  | 64 | EGL_ALPHA_SIZE, 8, | 
|  | 65 | EGL_NONE | 
|  | 66 | }; | 
|  | 67 | result = eglChooseConfig(mDisplay, configAttribs, &mConfig, 1, | 
|  | 68 | &numConfigs); | 
|  | 69 | if (result != EGL_TRUE) { | 
|  | 70 | fprintf(stderr, "eglChooseConfig error: %#x\n", eglGetError()); | 
|  | 71 | return false; | 
|  | 72 | } | 
|  | 73 |  | 
|  | 74 | EGLint contextAttribs[] = { | 
|  | 75 | EGL_CONTEXT_CLIENT_VERSION, 2, | 
|  | 76 | EGL_NONE | 
|  | 77 | }; | 
|  | 78 | mContext = eglCreateContext(mDisplay, mConfig, EGL_NO_CONTEXT, | 
|  | 79 | contextAttribs); | 
|  | 80 | if (mContext == EGL_NO_CONTEXT) { | 
|  | 81 | fprintf(stderr, "eglCreateContext error: %#x\n", eglGetError()); | 
|  | 82 | return false; | 
|  | 83 | } | 
|  | 84 |  | 
|  | 85 | bool resultb = createNamedSurfaceTexture(0, 1, 1, &mDummyGLConsumer, | 
|  | 86 | &mDummySurface); | 
|  | 87 | if (!resultb) { | 
|  | 88 | return false; | 
|  | 89 | } | 
|  | 90 |  | 
|  | 91 | resultb = makeCurrent(mDummySurface); | 
|  | 92 | if (!resultb) { | 
|  | 93 | return false; | 
|  | 94 | } | 
|  | 95 |  | 
|  | 96 | resultb = setUpShaders(shaderDescs, numShaders); | 
|  | 97 | if (!resultb) { | 
|  | 98 | return false; | 
|  | 99 | } | 
|  | 100 |  | 
|  | 101 | return true; | 
|  | 102 | } | 
|  | 103 |  | 
|  | 104 | void GLHelper::tearDown() { | 
|  | 105 | if (mShaderPrograms != NULL) { | 
|  | 106 | delete[] mShaderPrograms; | 
|  | 107 | mShaderPrograms = NULL; | 
|  | 108 | } | 
|  | 109 |  | 
|  | 110 | if (mSurfaceComposerClient != NULL) { | 
|  | 111 | mSurfaceComposerClient->dispose(); | 
|  | 112 | mSurfaceComposerClient.clear(); | 
|  | 113 | } | 
|  | 114 |  | 
|  | 115 | if (mDisplay != EGL_NO_DISPLAY) { | 
|  | 116 | eglMakeCurrent(mDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, | 
|  | 117 | EGL_NO_CONTEXT); | 
|  | 118 | } | 
|  | 119 |  | 
|  | 120 | if (mContext != EGL_NO_CONTEXT) { | 
|  | 121 | eglDestroyContext(mDisplay, mContext); | 
|  | 122 | } | 
|  | 123 |  | 
|  | 124 | if (mDummySurface != EGL_NO_SURFACE) { | 
|  | 125 | eglDestroySurface(mDisplay, mDummySurface); | 
|  | 126 | } | 
|  | 127 |  | 
|  | 128 | mDisplay = EGL_NO_DISPLAY; | 
|  | 129 | mContext = EGL_NO_CONTEXT; | 
|  | 130 | mDummySurface = EGL_NO_SURFACE; | 
|  | 131 | mDummyGLConsumer.clear(); | 
|  | 132 | mConfig = 0; | 
|  | 133 | } | 
|  | 134 |  | 
|  | 135 | bool GLHelper::makeCurrent(EGLSurface surface) { | 
|  | 136 | EGLint result; | 
|  | 137 |  | 
|  | 138 | result = eglMakeCurrent(mDisplay, surface, surface, mContext); | 
|  | 139 | if (result != EGL_TRUE) { | 
|  | 140 | fprintf(stderr, "eglMakeCurrent error: %#x\n", eglGetError()); | 
|  | 141 | return false; | 
|  | 142 | } | 
|  | 143 |  | 
|  | 144 | EGLint w, h; | 
|  | 145 | eglQuerySurface(mDisplay, surface, EGL_WIDTH, &w); | 
|  | 146 | eglQuerySurface(mDisplay, surface, EGL_HEIGHT, &h); | 
|  | 147 | glViewport(0, 0, w, h); | 
|  | 148 |  | 
|  | 149 | return true; | 
|  | 150 | } | 
|  | 151 |  | 
|  | 152 | bool GLHelper::createSurfaceTexture(uint32_t w, uint32_t h, | 
|  | 153 | sp<GLConsumer>* glConsumer, EGLSurface* surface, | 
|  | 154 | GLuint* name) { | 
|  | 155 | if (!makeCurrent(mDummySurface)) { | 
|  | 156 | return false; | 
|  | 157 | } | 
|  | 158 |  | 
|  | 159 | *name = 0; | 
|  | 160 | glGenTextures(1, name); | 
|  | 161 | if (*name == 0) { | 
|  | 162 | fprintf(stderr, "glGenTextures error: %#x\n", glGetError()); | 
|  | 163 | return false; | 
|  | 164 | } | 
|  | 165 |  | 
|  | 166 | return createNamedSurfaceTexture(*name, w, h, glConsumer, surface); | 
|  | 167 | } | 
|  | 168 |  | 
|  | 169 | void GLHelper::destroySurface(EGLSurface* surface) { | 
|  | 170 | if (eglGetCurrentSurface(EGL_READ) == *surface || | 
|  | 171 | eglGetCurrentSurface(EGL_DRAW) == *surface) { | 
|  | 172 | eglMakeCurrent(mDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, | 
|  | 173 | EGL_NO_CONTEXT); | 
|  | 174 | } | 
|  | 175 | eglDestroySurface(mDisplay, *surface); | 
|  | 176 | *surface = EGL_NO_SURFACE; | 
|  | 177 | } | 
|  | 178 |  | 
|  | 179 | bool GLHelper::swapBuffers(EGLSurface surface) { | 
|  | 180 | EGLint result; | 
|  | 181 | result = eglSwapBuffers(mDisplay, surface); | 
|  | 182 | if (result != EGL_TRUE) { | 
|  | 183 | fprintf(stderr, "eglSwapBuffers error: %#x\n", eglGetError()); | 
|  | 184 | return false; | 
|  | 185 | } | 
|  | 186 | return true; | 
|  | 187 | } | 
|  | 188 |  | 
|  | 189 | bool GLHelper::getShaderProgram(const char* name, GLuint* outPgm) { | 
|  | 190 | for (size_t i = 0; i < mNumShaders; i++) { | 
|  | 191 | if (strcmp(mShaderDescs[i].name, name) == 0) { | 
|  | 192 | *outPgm = mShaderPrograms[i]; | 
|  | 193 | return true; | 
|  | 194 | } | 
|  | 195 | } | 
|  | 196 |  | 
|  | 197 | fprintf(stderr, "unknown shader name: \"%s\"\n", name); | 
|  | 198 |  | 
|  | 199 | return false; | 
|  | 200 | } | 
|  | 201 |  | 
|  | 202 | bool GLHelper::createNamedSurfaceTexture(GLuint name, uint32_t w, uint32_t h, | 
|  | 203 | sp<GLConsumer>* glConsumer, EGLSurface* surface) { | 
| Dan Stoza | 6780a2d | 2014-03-13 11:31:43 -0700 | [diff] [blame] | 204 | sp<IGraphicBufferProducer> producer; | 
|  | 205 | sp<IGraphicBufferConsumer> consumer; | 
| Dan Stoza | 70982a5 | 2016-01-11 23:40:44 +0000 | [diff] [blame] | 206 | BufferQueue::createBufferQueue(&producer, &consumer, mGraphicBufferAlloc); | 
| Dan Stoza | 6780a2d | 2014-03-13 11:31:43 -0700 | [diff] [blame] | 207 | sp<GLConsumer> glc = new GLConsumer(consumer, name, | 
| Dan Stoza | e49ba8e | 2014-06-24 13:09:19 -0700 | [diff] [blame] | 208 | GL_TEXTURE_EXTERNAL_OES, false, true); | 
| Jamie Gennis | 9c183f2 | 2012-12-03 16:44:16 -0800 | [diff] [blame] | 209 | glc->setDefaultBufferSize(w, h); | 
| Pablo Ceballos | 19e3e06 | 2015-08-19 16:16:06 -0700 | [diff] [blame] | 210 | producer->setMaxDequeuedBufferCount(2); | 
| Jamie Gennis | 9c183f2 | 2012-12-03 16:44:16 -0800 | [diff] [blame] | 211 | glc->setConsumerUsageBits(GRALLOC_USAGE_HW_COMPOSER); | 
|  | 212 |  | 
| Dan Stoza | 6780a2d | 2014-03-13 11:31:43 -0700 | [diff] [blame] | 213 | sp<ANativeWindow> anw = new Surface(producer); | 
| Jamie Gennis | 9c183f2 | 2012-12-03 16:44:16 -0800 | [diff] [blame] | 214 | EGLSurface s = eglCreateWindowSurface(mDisplay, mConfig, anw.get(), NULL); | 
|  | 215 | if (s == EGL_NO_SURFACE) { | 
|  | 216 | fprintf(stderr, "eglCreateWindowSurface error: %#x\n", eglGetError()); | 
|  | 217 | return false; | 
|  | 218 | } | 
|  | 219 |  | 
|  | 220 | *glConsumer = glc; | 
|  | 221 | *surface = s; | 
|  | 222 | return true; | 
|  | 223 | } | 
|  | 224 |  | 
|  | 225 | bool GLHelper::computeWindowScale(uint32_t w, uint32_t h, float* scale) { | 
|  | 226 | sp<IBinder> dpy = mSurfaceComposerClient->getBuiltInDisplay(0); | 
|  | 227 | if (dpy == NULL) { | 
|  | 228 | fprintf(stderr, "SurfaceComposer::getBuiltInDisplay failed.\n"); | 
|  | 229 | return false; | 
|  | 230 | } | 
|  | 231 |  | 
|  | 232 | DisplayInfo info; | 
|  | 233 | status_t err = mSurfaceComposerClient->getDisplayInfo(dpy, &info); | 
|  | 234 | if (err != NO_ERROR) { | 
|  | 235 | fprintf(stderr, "SurfaceComposer::getDisplayInfo failed: %#x\n", err); | 
|  | 236 | return false; | 
|  | 237 | } | 
|  | 238 |  | 
|  | 239 | float scaleX = float(info.w) / float(w); | 
|  | 240 | float scaleY = float(info.h) / float(h); | 
|  | 241 | *scale = scaleX < scaleY ? scaleX : scaleY; | 
|  | 242 |  | 
|  | 243 | return true; | 
|  | 244 | } | 
|  | 245 |  | 
|  | 246 | bool GLHelper::createWindowSurface(uint32_t w, uint32_t h, | 
|  | 247 | sp<SurfaceControl>* surfaceControl, EGLSurface* surface) { | 
|  | 248 | bool result; | 
|  | 249 | status_t err; | 
|  | 250 |  | 
|  | 251 | if (mSurfaceComposerClient == NULL) { | 
|  | 252 | mSurfaceComposerClient = new SurfaceComposerClient; | 
|  | 253 | } | 
|  | 254 | err = mSurfaceComposerClient->initCheck(); | 
|  | 255 | if (err != NO_ERROR) { | 
|  | 256 | fprintf(stderr, "SurfaceComposerClient::initCheck error: %#x\n", err); | 
|  | 257 | return false; | 
|  | 258 | } | 
|  | 259 |  | 
|  | 260 | sp<SurfaceControl> sc = mSurfaceComposerClient->createSurface( | 
|  | 261 | String8("Benchmark"), w, h, PIXEL_FORMAT_RGBA_8888, 0); | 
|  | 262 | if (sc == NULL || !sc->isValid()) { | 
|  | 263 | fprintf(stderr, "Failed to create SurfaceControl.\n"); | 
|  | 264 | return false; | 
|  | 265 | } | 
|  | 266 |  | 
|  | 267 | float scale; | 
|  | 268 | result = computeWindowScale(w, h, &scale); | 
|  | 269 | if (!result) { | 
|  | 270 | return false; | 
|  | 271 | } | 
|  | 272 |  | 
|  | 273 | SurfaceComposerClient::openGlobalTransaction(); | 
|  | 274 | err = sc->setLayer(0x7FFFFFFF); | 
|  | 275 | if (err != NO_ERROR) { | 
|  | 276 | fprintf(stderr, "SurfaceComposer::setLayer error: %#x\n", err); | 
|  | 277 | return false; | 
|  | 278 | } | 
|  | 279 | err = sc->setMatrix(scale, 0.0f, 0.0f, scale); | 
|  | 280 | if (err != NO_ERROR) { | 
|  | 281 | fprintf(stderr, "SurfaceComposer::setMatrix error: %#x\n", err); | 
|  | 282 | return false; | 
|  | 283 | } | 
|  | 284 |  | 
|  | 285 | err = sc->show(); | 
|  | 286 | if (err != NO_ERROR) { | 
|  | 287 | fprintf(stderr, "SurfaceComposer::show error: %#x\n", err); | 
|  | 288 | return false; | 
|  | 289 | } | 
|  | 290 | SurfaceComposerClient::closeGlobalTransaction(); | 
|  | 291 |  | 
|  | 292 | sp<ANativeWindow> anw = sc->getSurface(); | 
|  | 293 | EGLSurface s = eglCreateWindowSurface(mDisplay, mConfig, anw.get(), NULL); | 
|  | 294 | if (s == EGL_NO_SURFACE) { | 
|  | 295 | fprintf(stderr, "eglCreateWindowSurface error: %#x\n", eglGetError()); | 
|  | 296 | return false; | 
|  | 297 | } | 
|  | 298 |  | 
|  | 299 | *surfaceControl = sc; | 
|  | 300 | *surface = s; | 
|  | 301 | return true; | 
|  | 302 | } | 
|  | 303 |  | 
|  | 304 | static bool compileShader(GLenum shaderType, const char* src, | 
|  | 305 | GLuint* outShader) { | 
|  | 306 | GLuint shader = glCreateShader(shaderType); | 
|  | 307 | if (shader == 0) { | 
|  | 308 | fprintf(stderr, "glCreateShader error: %#x\n", glGetError()); | 
|  | 309 | return false; | 
|  | 310 | } | 
|  | 311 |  | 
|  | 312 | glShaderSource(shader, 1, &src, NULL); | 
|  | 313 | glCompileShader(shader); | 
|  | 314 |  | 
|  | 315 | GLint compiled = 0; | 
|  | 316 | glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled); | 
|  | 317 | if (!compiled) { | 
|  | 318 | GLint infoLen = 0; | 
|  | 319 | glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &infoLen); | 
|  | 320 | if (infoLen) { | 
|  | 321 | char* buf = new char[infoLen]; | 
|  | 322 | if (buf) { | 
|  | 323 | glGetShaderInfoLog(shader, infoLen, NULL, buf); | 
|  | 324 | fprintf(stderr, "Shader compile log:\n%s\n", buf); | 
|  | 325 | delete[] buf; | 
|  | 326 | } | 
|  | 327 | } | 
|  | 328 | glDeleteShader(shader); | 
|  | 329 | return false; | 
|  | 330 | } | 
|  | 331 | *outShader = shader; | 
|  | 332 | return true; | 
|  | 333 | } | 
|  | 334 |  | 
|  | 335 | static void printShaderSource(const char* const* src) { | 
|  | 336 | for (size_t i = 0; i < MAX_SHADER_LINES && src[i] != NULL; i++) { | 
| Mark Salyzyn | 92dc3fc | 2014-03-12 13:12:44 -0700 | [diff] [blame] | 337 | fprintf(stderr, "%3zu: %s\n", i+1, src[i]); | 
| Jamie Gennis | 9c183f2 | 2012-12-03 16:44:16 -0800 | [diff] [blame] | 338 | } | 
|  | 339 | } | 
|  | 340 |  | 
|  | 341 | static const char* makeShaderString(const char* const* src) { | 
|  | 342 | size_t len = 0; | 
|  | 343 | for (size_t i = 0; i < MAX_SHADER_LINES && src[i] != NULL; i++) { | 
|  | 344 | // The +1 is for the '\n' that will be added. | 
|  | 345 | len += strlen(src[i]) + 1; | 
|  | 346 | } | 
|  | 347 |  | 
|  | 348 | char* result = new char[len+1]; | 
|  | 349 | char* end = result; | 
|  | 350 | for (size_t i = 0; i < MAX_SHADER_LINES && src[i] != NULL; i++) { | 
|  | 351 | strcpy(end, src[i]); | 
|  | 352 | end += strlen(src[i]); | 
|  | 353 | *end = '\n'; | 
|  | 354 | end++; | 
|  | 355 | } | 
|  | 356 | *end = '\0'; | 
|  | 357 |  | 
|  | 358 | return result; | 
|  | 359 | } | 
|  | 360 |  | 
|  | 361 | static bool compileShaderLines(GLenum shaderType, const char* const* lines, | 
|  | 362 | GLuint* outShader) { | 
|  | 363 | const char* src = makeShaderString(lines); | 
|  | 364 | bool result = compileShader(shaderType, src, outShader); | 
|  | 365 | if (!result) { | 
|  | 366 | fprintf(stderr, "Shader source:\n"); | 
|  | 367 | printShaderSource(lines); | 
|  | 368 | return false; | 
|  | 369 | } | 
|  | 370 | delete[] src; | 
|  | 371 |  | 
|  | 372 | return true; | 
|  | 373 | } | 
|  | 374 |  | 
|  | 375 | static bool linkShaderProgram(GLuint vs, GLuint fs, GLuint* outPgm) { | 
|  | 376 | GLuint program = glCreateProgram(); | 
|  | 377 | if (program == 0) { | 
|  | 378 | fprintf(stderr, "glCreateProgram error: %#x\n", glGetError()); | 
|  | 379 | return false; | 
|  | 380 | } | 
|  | 381 |  | 
|  | 382 | glAttachShader(program, vs); | 
|  | 383 | glAttachShader(program, fs); | 
|  | 384 | glLinkProgram(program); | 
|  | 385 | GLint linkStatus = GL_FALSE; | 
|  | 386 | glGetProgramiv(program, GL_LINK_STATUS, &linkStatus); | 
|  | 387 | if (linkStatus != GL_TRUE) { | 
|  | 388 | GLint bufLength = 0; | 
|  | 389 | glGetProgramiv(program, GL_INFO_LOG_LENGTH, &bufLength); | 
|  | 390 | if (bufLength) { | 
|  | 391 | char* buf = new char[bufLength]; | 
|  | 392 | if (buf) { | 
|  | 393 | glGetProgramInfoLog(program, bufLength, NULL, buf); | 
|  | 394 | fprintf(stderr, "Program link log:\n%s\n", buf); | 
|  | 395 | delete[] buf; | 
|  | 396 | } | 
|  | 397 | } | 
|  | 398 | glDeleteProgram(program); | 
|  | 399 | program = 0; | 
|  | 400 | } | 
|  | 401 |  | 
|  | 402 | *outPgm = program; | 
|  | 403 | return program != 0; | 
|  | 404 | } | 
|  | 405 |  | 
|  | 406 | bool GLHelper::setUpShaders(const ShaderDesc* shaderDescs, size_t numShaders) { | 
|  | 407 | mShaderPrograms = new GLuint[numShaders]; | 
|  | 408 | bool result = true; | 
|  | 409 |  | 
|  | 410 | for (size_t i = 0; i < numShaders && result; i++) { | 
|  | 411 | GLuint vs, fs; | 
|  | 412 |  | 
|  | 413 | result = compileShaderLines(GL_VERTEX_SHADER, | 
|  | 414 | shaderDescs[i].vertexShader, &vs); | 
|  | 415 | if (!result) { | 
|  | 416 | return false; | 
|  | 417 | } | 
|  | 418 |  | 
|  | 419 | result = compileShaderLines(GL_FRAGMENT_SHADER, | 
|  | 420 | shaderDescs[i].fragmentShader, &fs); | 
|  | 421 | if (!result) { | 
|  | 422 | glDeleteShader(vs); | 
|  | 423 | return false; | 
|  | 424 | } | 
|  | 425 |  | 
|  | 426 | result = linkShaderProgram(vs, fs, &mShaderPrograms[i]); | 
|  | 427 | glDeleteShader(vs); | 
|  | 428 | glDeleteShader(fs); | 
|  | 429 | } | 
|  | 430 |  | 
|  | 431 | mNumShaders = numShaders; | 
|  | 432 | mShaderDescs = shaderDescs; | 
|  | 433 |  | 
|  | 434 | return result; | 
|  | 435 | } | 
|  | 436 |  | 
|  | 437 | bool GLHelper::getDitherTexture(GLuint* outTexName) { | 
|  | 438 | if (mDitherTexture == 0) { | 
|  | 439 | const uint8_t pattern[] = { | 
|  | 440 | 0,  8,  2, 10, | 
|  | 441 | 12,  4, 14,  6, | 
|  | 442 | 3, 11,  1,  9, | 
|  | 443 | 15,  7, 13,  5 | 
|  | 444 | }; | 
|  | 445 |  | 
|  | 446 | glGenTextures(1, &mDitherTexture); | 
|  | 447 | glBindTexture(GL_TEXTURE_2D, mDitherTexture); | 
|  | 448 |  | 
|  | 449 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); | 
|  | 450 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); | 
|  | 451 |  | 
|  | 452 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); | 
|  | 453 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); | 
|  | 454 |  | 
|  | 455 | glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, DITHER_KERNEL_SIZE, | 
|  | 456 | DITHER_KERNEL_SIZE, 0, GL_ALPHA, GL_UNSIGNED_BYTE, &pattern); | 
|  | 457 | } | 
|  | 458 |  | 
|  | 459 | *outTexName = mDitherTexture; | 
|  | 460 |  | 
|  | 461 | return true; | 
|  | 462 | } | 
|  | 463 |  | 
|  | 464 | } |