michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* vim: set ts=8 sts=4 et sw=4 tw=80: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "GLBlitHelper.h"
michael@0: #include "GLContext.h"
michael@0: #include "ScopedGLHelpers.h"
michael@0: #include "mozilla/Preferences.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace gl {
michael@0: 
michael@0: static void
michael@0: RenderbufferStorageBySamples(GLContext* aGL, GLsizei aSamples,
michael@0:                              GLenum aInternalFormat, const gfx::IntSize& aSize)
michael@0: {
michael@0:     if (aSamples) {
michael@0:         aGL->fRenderbufferStorageMultisample(LOCAL_GL_RENDERBUFFER,
michael@0:                                              aSamples,
michael@0:                                              aInternalFormat,
michael@0:                                              aSize.width, aSize.height);
michael@0:     } else {
michael@0:         aGL->fRenderbufferStorage(LOCAL_GL_RENDERBUFFER,
michael@0:                                   aInternalFormat,
michael@0:                                   aSize.width, aSize.height);
michael@0:     }
michael@0: }
michael@0: 
michael@0: 
michael@0: GLuint
michael@0: CreateTexture(GLContext* aGL, GLenum aInternalFormat, GLenum aFormat,
michael@0:               GLenum aType, const gfx::IntSize& aSize)
michael@0: {
michael@0:     GLuint tex = 0;
michael@0:     aGL->fGenTextures(1, &tex);
michael@0:     ScopedBindTexture autoTex(aGL, tex);
michael@0: 
michael@0:     aGL->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_MIN_FILTER, LOCAL_GL_LINEAR);
michael@0:     aGL->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_MAG_FILTER, LOCAL_GL_LINEAR);
michael@0:     aGL->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_WRAP_S, LOCAL_GL_CLAMP_TO_EDGE);
michael@0:     aGL->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_WRAP_T, LOCAL_GL_CLAMP_TO_EDGE);
michael@0: 
michael@0:     aGL->fTexImage2D(LOCAL_GL_TEXTURE_2D,
michael@0:                      0,
michael@0:                      aInternalFormat,
michael@0:                      aSize.width, aSize.height,
michael@0:                      0,
michael@0:                      aFormat,
michael@0:                      aType,
michael@0:                      nullptr);
michael@0: 
michael@0:     return tex;
michael@0: }
michael@0: 
michael@0: 
michael@0: GLuint
michael@0: CreateTextureForOffscreen(GLContext* aGL, const GLFormats& aFormats,
michael@0:                           const gfx::IntSize& aSize)
michael@0: {
michael@0:     MOZ_ASSERT(aFormats.color_texInternalFormat);
michael@0:     MOZ_ASSERT(aFormats.color_texFormat);
michael@0:     MOZ_ASSERT(aFormats.color_texType);
michael@0: 
michael@0:     return CreateTexture(aGL,
michael@0:                          aFormats.color_texInternalFormat,
michael@0:                          aFormats.color_texFormat,
michael@0:                          aFormats.color_texType,
michael@0:                          aSize);
michael@0: }
michael@0: 
michael@0: 
michael@0: GLuint
michael@0: CreateRenderbuffer(GLContext* aGL, GLenum aFormat, GLsizei aSamples,
michael@0:                    const gfx::IntSize& aSize)
michael@0: {
michael@0:     GLuint rb = 0;
michael@0:     aGL->fGenRenderbuffers(1, &rb);
michael@0:     ScopedBindRenderbuffer autoRB(aGL, rb);
michael@0: 
michael@0:     RenderbufferStorageBySamples(aGL, aSamples, aFormat, aSize);
michael@0: 
michael@0:     return rb;
michael@0: }
michael@0: 
michael@0: 
michael@0: void
michael@0: CreateRenderbuffersForOffscreen(GLContext* aGL, const GLFormats& aFormats,
michael@0:                                 const gfx::IntSize& aSize, bool aMultisample,
michael@0:                                 GLuint* aColorMSRB, GLuint* aDepthRB,
michael@0:                                 GLuint* aStencilRB)
michael@0: {
michael@0:     GLsizei samples = aMultisample ? aFormats.samples : 0;
michael@0:     if (aColorMSRB) {
michael@0:         MOZ_ASSERT(aFormats.samples > 0);
michael@0:         MOZ_ASSERT(aFormats.color_rbFormat);
michael@0: 
michael@0:         *aColorMSRB = CreateRenderbuffer(aGL, aFormats.color_rbFormat, samples, aSize);
michael@0:     }
michael@0: 
michael@0:     if (aDepthRB &&
michael@0:         aStencilRB &&
michael@0:         aFormats.depthStencil)
michael@0:     {
michael@0:         *aDepthRB = CreateRenderbuffer(aGL, aFormats.depthStencil, samples, aSize);
michael@0:         *aStencilRB = *aDepthRB;
michael@0:     } else {
michael@0:         if (aDepthRB) {
michael@0:             MOZ_ASSERT(aFormats.depth);
michael@0: 
michael@0:             *aDepthRB = CreateRenderbuffer(aGL, aFormats.depth, samples, aSize);
michael@0:         }
michael@0: 
michael@0:         if (aStencilRB) {
michael@0:             MOZ_ASSERT(aFormats.stencil);
michael@0: 
michael@0:             *aStencilRB = CreateRenderbuffer(aGL, aFormats.stencil, samples, aSize);
michael@0:         }
michael@0:     }
michael@0: }
michael@0: 
michael@0: 
michael@0: GLBlitHelper::GLBlitHelper(GLContext* gl)
michael@0:     : mGL(gl)
michael@0:     , mTexBlit_Buffer(0)
michael@0:     , mTexBlit_VertShader(0)
michael@0:     , mTex2DBlit_FragShader(0)
michael@0:     , mTex2DRectBlit_FragShader(0)
michael@0:     , mTex2DBlit_Program(0)
michael@0:     , mTex2DRectBlit_Program(0)
michael@0: {
michael@0: }
michael@0: 
michael@0: GLBlitHelper::~GLBlitHelper()
michael@0: {
michael@0:     DeleteTexBlitProgram();
michael@0: }
michael@0: 
michael@0: // Allowed to be destructive of state we restore in functions below.
michael@0: bool
michael@0: GLBlitHelper::InitTexQuadProgram(GLenum target)
michael@0: {
michael@0:     const char kTexBlit_VertShaderSource[] = "\
michael@0:     attribute vec2 aPosition;                   \n\
michael@0:                                                 \n\
michael@0:     varying vec2 vTexCoord;                     \n\
michael@0:                                                 \n\
michael@0:     void main(void) {                           \n\
michael@0:         vTexCoord = aPosition;                  \n\
michael@0:         vec2 vertPos = aPosition * 2.0 - 1.0;   \n\
michael@0:         gl_Position = vec4(vertPos, 0.0, 1.0);  \n\
michael@0:     }                                           \n\
michael@0:     ";
michael@0: 
michael@0:     const char kTex2DBlit_FragShaderSource[] = "\
michael@0:     #ifdef GL_FRAGMENT_PRECISION_HIGH                   \n\
michael@0:         precision highp float;                          \n\
michael@0:     #else                                               \n\
michael@0:         precision mediump float;                        \n\
michael@0:     #endif                                              \n\
michael@0:                                                         \n\
michael@0:     uniform sampler2D uTexUnit;                         \n\
michael@0:                                                         \n\
michael@0:     varying vec2 vTexCoord;                             \n\
michael@0:                                                         \n\
michael@0:     void main(void) {                                   \n\
michael@0:         gl_FragColor = texture2D(uTexUnit, vTexCoord);  \n\
michael@0:     }                                                   \n\
michael@0:     ";
michael@0: 
michael@0:     const char kTex2DRectBlit_FragShaderSource[] = "\
michael@0:     #ifdef GL_FRAGMENT_PRECISION_HIGH                             \n\
michael@0:         precision highp float;                                    \n\
michael@0:     #else                                                         \n\
michael@0:         precision mediump float;                                  \n\
michael@0:     #endif                                                        \n\
michael@0:                                                                   \n\
michael@0:     uniform sampler2D uTexUnit;                                   \n\
michael@0:     uniform vec2 uTexCoordMult;                                   \n\
michael@0:                                                                   \n\
michael@0:     varying vec2 vTexCoord;                                       \n\
michael@0:                                                                   \n\
michael@0:     void main(void) {                                             \n\
michael@0:         gl_FragColor = texture2DRect(uTexUnit,                    \n\
michael@0:                                     vTexCoord * uTexCoordMult);  \n\
michael@0:     }                                                             \n\
michael@0:     ";
michael@0: 
michael@0:     MOZ_ASSERT(target == LOCAL_GL_TEXTURE_2D ||
michael@0:                target == LOCAL_GL_TEXTURE_RECTANGLE_ARB);
michael@0:     bool success = false;
michael@0: 
michael@0:     GLuint *programPtr;
michael@0:     GLuint *fragShaderPtr;
michael@0:     const char* fragShaderSource;
michael@0:     if (target == LOCAL_GL_TEXTURE_2D) {
michael@0:         programPtr = &mTex2DBlit_Program;
michael@0:         fragShaderPtr = &mTex2DBlit_FragShader;
michael@0:         fragShaderSource = kTex2DBlit_FragShaderSource;
michael@0:     } else {
michael@0:         programPtr = &mTex2DRectBlit_Program;
michael@0:         fragShaderPtr = &mTex2DRectBlit_FragShader;
michael@0:         fragShaderSource = kTex2DRectBlit_FragShaderSource;
michael@0:     }
michael@0: 
michael@0:     GLuint& program = *programPtr;
michael@0:     GLuint& fragShader = *fragShaderPtr;
michael@0: 
michael@0:     // Use do-while(false) to let us break on failure
michael@0:     do {
michael@0:         if (program) {
michael@0:             // Already have it...
michael@0:             success = true;
michael@0:             break;
michael@0:         }
michael@0: 
michael@0:         if (!mTexBlit_Buffer) {
michael@0: 
michael@0:             /* CCW tri-strip:
michael@0:              * 2---3
michael@0:              * | \ |
michael@0:              * 0---1
michael@0:              */
michael@0:             GLfloat verts[] = {
michael@0:                 0.0f, 0.0f,
michael@0:                 1.0f, 0.0f,
michael@0:                 0.0f, 1.0f,
michael@0:                 1.0f, 1.0f
michael@0:             };
michael@0: 
michael@0:             MOZ_ASSERT(!mTexBlit_Buffer);
michael@0:             mGL->fGenBuffers(1, &mTexBlit_Buffer);
michael@0:             mGL->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mTexBlit_Buffer);
michael@0: 
michael@0:             const size_t vertsSize = sizeof(verts);
michael@0:             // Make sure we have a sane size.
michael@0:             MOZ_ASSERT(vertsSize >= 3 * sizeof(GLfloat));
michael@0:             mGL->fBufferData(LOCAL_GL_ARRAY_BUFFER, vertsSize, verts, LOCAL_GL_STATIC_DRAW);
michael@0:         }
michael@0: 
michael@0:         if (!mTexBlit_VertShader) {
michael@0: 
michael@0:             const char* vertShaderSource = kTexBlit_VertShaderSource;
michael@0: 
michael@0:             mTexBlit_VertShader = mGL->fCreateShader(LOCAL_GL_VERTEX_SHADER);
michael@0:             mGL->fShaderSource(mTexBlit_VertShader, 1, &vertShaderSource, nullptr);
michael@0:             mGL->fCompileShader(mTexBlit_VertShader);
michael@0:         }
michael@0: 
michael@0:         MOZ_ASSERT(!fragShader);
michael@0:         fragShader = mGL->fCreateShader(LOCAL_GL_FRAGMENT_SHADER);
michael@0:         mGL->fShaderSource(fragShader, 1, &fragShaderSource, nullptr);
michael@0:         mGL->fCompileShader(fragShader);
michael@0: 
michael@0:         program = mGL->fCreateProgram();
michael@0:         mGL->fAttachShader(program, mTexBlit_VertShader);
michael@0:         mGL->fAttachShader(program, fragShader);
michael@0:         mGL->fBindAttribLocation(program, 0, "aPosition");
michael@0:         mGL->fLinkProgram(program);
michael@0: 
michael@0:         if (mGL->DebugMode()) {
michael@0:             GLint status = 0;
michael@0:             mGL->fGetShaderiv(mTexBlit_VertShader, LOCAL_GL_COMPILE_STATUS, &status);
michael@0:             if (status != LOCAL_GL_TRUE) {
michael@0:                 NS_ERROR("Vert shader compilation failed.");
michael@0: 
michael@0:                 GLint length = 0;
michael@0:                 mGL->fGetShaderiv(mTexBlit_VertShader, LOCAL_GL_INFO_LOG_LENGTH, &length);
michael@0:                 if (!length) {
michael@0:                     printf_stderr("No shader info log available.\n");
michael@0:                     break;
michael@0:                 }
michael@0: 
michael@0:                 nsAutoArrayPtr<char> buffer(new char[length]);
michael@0:                 mGL->fGetShaderInfoLog(mTexBlit_VertShader, length, nullptr, buffer);
michael@0: 
michael@0:                 printf_stderr("Shader info log (%d bytes): %s\n", length, buffer.get());
michael@0:                 break;
michael@0:             }
michael@0: 
michael@0:             status = 0;
michael@0:             mGL->fGetShaderiv(fragShader, LOCAL_GL_COMPILE_STATUS, &status);
michael@0:             if (status != LOCAL_GL_TRUE) {
michael@0:                 NS_ERROR("Frag shader compilation failed.");
michael@0: 
michael@0:                 GLint length = 0;
michael@0:                 mGL->fGetShaderiv(fragShader, LOCAL_GL_INFO_LOG_LENGTH, &length);
michael@0:                 if (!length) {
michael@0:                     printf_stderr("No shader info log available.\n");
michael@0:                     break;
michael@0:                 }
michael@0: 
michael@0:                 nsAutoArrayPtr<char> buffer(new char[length]);
michael@0:                 mGL->fGetShaderInfoLog(fragShader, length, nullptr, buffer);
michael@0: 
michael@0:                 printf_stderr("Shader info log (%d bytes): %s\n", length, buffer.get());
michael@0:                 break;
michael@0:             }
michael@0:         }
michael@0: 
michael@0:         GLint status = 0;
michael@0:         mGL->fGetProgramiv(program, LOCAL_GL_LINK_STATUS, &status);
michael@0:         if (status != LOCAL_GL_TRUE) {
michael@0:             if (mGL->DebugMode()) {
michael@0:                 NS_ERROR("Linking blit program failed.");
michael@0:                 GLint length = 0;
michael@0:                 mGL->fGetProgramiv(program, LOCAL_GL_INFO_LOG_LENGTH, &length);
michael@0:                 if (!length) {
michael@0:                     printf_stderr("No program info log available.\n");
michael@0:                     break;
michael@0:                 }
michael@0: 
michael@0:                 nsAutoArrayPtr<char> buffer(new char[length]);
michael@0:                 mGL->fGetProgramInfoLog(program, length, nullptr, buffer);
michael@0: 
michael@0:                 printf_stderr("Program info log (%d bytes): %s\n", length, buffer.get());
michael@0:             }
michael@0:             break;
michael@0:         }
michael@0: 
michael@0:         MOZ_ASSERT(mGL->fGetAttribLocation(program, "aPosition") == 0);
michael@0:         GLint texUnitLoc = mGL->fGetUniformLocation(program, "uTexUnit");
michael@0:         MOZ_ASSERT(texUnitLoc != -1, "uniform not found");
michael@0: 
michael@0:         // Set uniforms here:
michael@0:         mGL->fUseProgram(program);
michael@0:         mGL->fUniform1i(texUnitLoc, 0);
michael@0: 
michael@0:         success = true;
michael@0:     } while (false);
michael@0: 
michael@0:     if (!success) {
michael@0:         NS_ERROR("Creating program for texture blit failed!");
michael@0: 
michael@0:         // Clean up:
michael@0:         DeleteTexBlitProgram();
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     mGL->fUseProgram(program);
michael@0:     mGL->fEnableVertexAttribArray(0);
michael@0:     mGL->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mTexBlit_Buffer);
michael@0:     mGL->fVertexAttribPointer(0,
michael@0:                               2,
michael@0:                               LOCAL_GL_FLOAT,
michael@0:                               false,
michael@0:                               0,
michael@0:                               nullptr);
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool
michael@0: GLBlitHelper::UseTexQuadProgram(GLenum target, const gfx::IntSize& srcSize)
michael@0: {
michael@0:     if (!InitTexQuadProgram(target)) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     if (target == LOCAL_GL_TEXTURE_RECTANGLE_ARB) {
michael@0:         GLint texCoordMultLoc = mGL->fGetUniformLocation(mTex2DRectBlit_Program, "uTexCoordMult");
michael@0:         MOZ_ASSERT(texCoordMultLoc != -1, "uniform not found");
michael@0:         mGL->fUniform2f(texCoordMultLoc, srcSize.width, srcSize.height);
michael@0:     }
michael@0: 
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: void
michael@0: GLBlitHelper::DeleteTexBlitProgram()
michael@0: {
michael@0:     if (mTexBlit_Buffer) {
michael@0:         mGL->fDeleteBuffers(1, &mTexBlit_Buffer);
michael@0:         mTexBlit_Buffer = 0;
michael@0:     }
michael@0:     if (mTexBlit_VertShader) {
michael@0:         mGL->fDeleteShader(mTexBlit_VertShader);
michael@0:         mTexBlit_VertShader = 0;
michael@0:     }
michael@0:     if (mTex2DBlit_FragShader) {
michael@0:         mGL->fDeleteShader(mTex2DBlit_FragShader);
michael@0:         mTex2DBlit_FragShader = 0;
michael@0:     }
michael@0:     if (mTex2DRectBlit_FragShader) {
michael@0:         mGL->fDeleteShader(mTex2DRectBlit_FragShader);
michael@0:         mTex2DRectBlit_FragShader = 0;
michael@0:     }
michael@0:     if (mTex2DBlit_Program) {
michael@0:         mGL->fDeleteProgram(mTex2DBlit_Program);
michael@0:         mTex2DBlit_Program = 0;
michael@0:     }
michael@0:     if (mTex2DRectBlit_Program) {
michael@0:         mGL->fDeleteProgram(mTex2DRectBlit_Program);
michael@0:         mTex2DRectBlit_Program = 0;
michael@0:     }
michael@0: }
michael@0: 
michael@0: void
michael@0: GLBlitHelper::BlitFramebufferToFramebuffer(GLuint srcFB, GLuint destFB,
michael@0:                                         const gfx::IntSize& srcSize,
michael@0:                                         const gfx::IntSize& destSize)
michael@0: {
michael@0:     MOZ_ASSERT(!srcFB || mGL->fIsFramebuffer(srcFB));
michael@0:     MOZ_ASSERT(!destFB || mGL->fIsFramebuffer(destFB));
michael@0: 
michael@0:     MOZ_ASSERT(mGL->IsSupported(GLFeature::framebuffer_blit));
michael@0: 
michael@0:     ScopedBindFramebuffer boundFB(mGL);
michael@0:     ScopedGLState scissor(mGL, LOCAL_GL_SCISSOR_TEST, false);
michael@0: 
michael@0:     mGL->BindReadFB(srcFB);
michael@0:     mGL->BindDrawFB(destFB);
michael@0: 
michael@0:     mGL->fBlitFramebuffer(0, 0,  srcSize.width,  srcSize.height,
michael@0:                           0, 0, destSize.width, destSize.height,
michael@0:                           LOCAL_GL_COLOR_BUFFER_BIT,
michael@0:                           LOCAL_GL_NEAREST);
michael@0: }
michael@0: 
michael@0: void
michael@0: GLBlitHelper::BlitFramebufferToFramebuffer(GLuint srcFB, GLuint destFB,
michael@0:                                         const gfx::IntSize& srcSize,
michael@0:                                         const gfx::IntSize& destSize,
michael@0:                                         const GLFormats& srcFormats)
michael@0: {
michael@0:     MOZ_ASSERT(!srcFB || mGL->fIsFramebuffer(srcFB));
michael@0:     MOZ_ASSERT(!destFB || mGL->fIsFramebuffer(destFB));
michael@0: 
michael@0:     if (mGL->IsSupported(GLFeature::framebuffer_blit)) {
michael@0:         BlitFramebufferToFramebuffer(srcFB, destFB,
michael@0:                                      srcSize, destSize);
michael@0:         return;
michael@0:     }
michael@0: 
michael@0:     GLuint tex = CreateTextureForOffscreen(mGL, srcFormats, srcSize);
michael@0:     MOZ_ASSERT(tex);
michael@0: 
michael@0:     BlitFramebufferToTexture(srcFB, tex, srcSize, srcSize);
michael@0:     BlitTextureToFramebuffer(tex, destFB, srcSize, destSize);
michael@0: 
michael@0:     mGL->fDeleteTextures(1, &tex);
michael@0: }
michael@0: 
michael@0: void
michael@0: GLBlitHelper::BlitTextureToFramebuffer(GLuint srcTex, GLuint destFB,
michael@0:                                     const gfx::IntSize& srcSize,
michael@0:                                     const gfx::IntSize& destSize,
michael@0:                                     GLenum srcTarget)
michael@0: {
michael@0:     MOZ_ASSERT(mGL->fIsTexture(srcTex));
michael@0:     MOZ_ASSERT(!destFB || mGL->fIsFramebuffer(destFB));
michael@0: 
michael@0:     if (mGL->IsSupported(GLFeature::framebuffer_blit)) {
michael@0:         ScopedFramebufferForTexture srcWrapper(mGL, srcTex, srcTarget);
michael@0:         MOZ_ASSERT(srcWrapper.IsComplete());
michael@0: 
michael@0:         BlitFramebufferToFramebuffer(srcWrapper.FB(), destFB,
michael@0:                                      srcSize, destSize);
michael@0:         return;
michael@0:     }
michael@0: 
michael@0: 
michael@0:     ScopedBindFramebuffer boundFB(mGL, destFB);
michael@0:     // UseTexQuadProgram initializes a shader that reads
michael@0:     // from texture unit 0.
michael@0:     ScopedBindTextureUnit boundTU(mGL, LOCAL_GL_TEXTURE0);
michael@0:     ScopedBindTexture boundTex(mGL, srcTex, srcTarget);
michael@0: 
michael@0:     GLuint boundProgram = 0;
michael@0:     mGL->GetUIntegerv(LOCAL_GL_CURRENT_PROGRAM, &boundProgram);
michael@0: 
michael@0:     GLuint boundBuffer = 0;
michael@0:     mGL->GetUIntegerv(LOCAL_GL_ARRAY_BUFFER_BINDING, &boundBuffer);
michael@0: 
michael@0:     /*
michael@0:      * mGL->fGetVertexAttribiv takes:
michael@0:      *  VERTEX_ATTRIB_ARRAY_ENABLED
michael@0:      *  VERTEX_ATTRIB_ARRAY_SIZE,
michael@0:      *  VERTEX_ATTRIB_ARRAY_STRIDE,
michael@0:      *  VERTEX_ATTRIB_ARRAY_TYPE,
michael@0:      *  VERTEX_ATTRIB_ARRAY_NORMALIZED,
michael@0:      *  VERTEX_ATTRIB_ARRAY_BUFFER_BINDING,
michael@0:      *  CURRENT_VERTEX_ATTRIB
michael@0:      *
michael@0:      * CURRENT_VERTEX_ATTRIB is vertex shader state. \o/
michael@0:      * Others appear to be vertex array state,
michael@0:      * or alternatively in the internal vertex array state
michael@0:      * for a buffer object.
michael@0:     */
michael@0: 
michael@0:     GLint attrib0_enabled = 0;
michael@0:     GLint attrib0_size = 0;
michael@0:     GLint attrib0_stride = 0;
michael@0:     GLint attrib0_type = 0;
michael@0:     GLint attrib0_normalized = 0;
michael@0:     GLint attrib0_bufferBinding = 0;
michael@0:     void* attrib0_pointer = nullptr;
michael@0: 
michael@0:     mGL->fGetVertexAttribiv(0, LOCAL_GL_VERTEX_ATTRIB_ARRAY_ENABLED, &attrib0_enabled);
michael@0:     mGL->fGetVertexAttribiv(0, LOCAL_GL_VERTEX_ATTRIB_ARRAY_SIZE, &attrib0_size);
michael@0:     mGL->fGetVertexAttribiv(0, LOCAL_GL_VERTEX_ATTRIB_ARRAY_STRIDE, &attrib0_stride);
michael@0:     mGL->fGetVertexAttribiv(0, LOCAL_GL_VERTEX_ATTRIB_ARRAY_TYPE, &attrib0_type);
michael@0:     mGL->fGetVertexAttribiv(0, LOCAL_GL_VERTEX_ATTRIB_ARRAY_NORMALIZED, &attrib0_normalized);
michael@0:     mGL->fGetVertexAttribiv(0, LOCAL_GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING, &attrib0_bufferBinding);
michael@0:     mGL->fGetVertexAttribPointerv(0, LOCAL_GL_VERTEX_ATTRIB_ARRAY_POINTER, &attrib0_pointer);
michael@0:     // Note that uniform values are program state, so we don't need to rebind those.
michael@0: 
michael@0:     ScopedGLState blend       (mGL, LOCAL_GL_BLEND,      false);
michael@0:     ScopedGLState cullFace    (mGL, LOCAL_GL_CULL_FACE,  false);
michael@0:     ScopedGLState depthTest   (mGL, LOCAL_GL_DEPTH_TEST, false);
michael@0:     ScopedGLState dither      (mGL, LOCAL_GL_DITHER,     false);
michael@0:     ScopedGLState polyOffsFill(mGL, LOCAL_GL_POLYGON_OFFSET_FILL,      false);
michael@0:     ScopedGLState sampleAToC  (mGL, LOCAL_GL_SAMPLE_ALPHA_TO_COVERAGE, false);
michael@0:     ScopedGLState sampleCover (mGL, LOCAL_GL_SAMPLE_COVERAGE, false);
michael@0:     ScopedGLState scissor     (mGL, LOCAL_GL_SCISSOR_TEST,    false);
michael@0:     ScopedGLState stencil     (mGL, LOCAL_GL_STENCIL_TEST,    false);
michael@0: 
michael@0:     realGLboolean colorMask[4];
michael@0:     mGL->fGetBooleanv(LOCAL_GL_COLOR_WRITEMASK, colorMask);
michael@0:     mGL->fColorMask(LOCAL_GL_TRUE,
michael@0:                     LOCAL_GL_TRUE,
michael@0:                     LOCAL_GL_TRUE,
michael@0:                     LOCAL_GL_TRUE);
michael@0: 
michael@0:     GLint viewport[4];
michael@0:     mGL->fGetIntegerv(LOCAL_GL_VIEWPORT, viewport);
michael@0:     mGL->fViewport(0, 0, destSize.width, destSize.height);
michael@0: 
michael@0:     // Does destructive things to (only!) what we just saved above.
michael@0:     bool good = UseTexQuadProgram(srcTarget, srcSize);
michael@0:     if (!good) {
michael@0:         // We're up against the wall, so bail.
michael@0:         // This should really be MOZ_CRASH(why) or MOZ_RUNTIME_ASSERT(good).
michael@0:         printf_stderr("[%s:%d] Fatal Error: Failed to prepare to blit texture->framebuffer.\n",
michael@0:                       __FILE__, __LINE__);
michael@0:         MOZ_CRASH();
michael@0:     }
michael@0:     mGL->fDrawArrays(LOCAL_GL_TRIANGLE_STRIP, 0, 4);
michael@0: 
michael@0:     mGL->fViewport(viewport[0], viewport[1],
michael@0:                    viewport[2], viewport[3]);
michael@0: 
michael@0:     mGL->fColorMask(colorMask[0],
michael@0:                     colorMask[1],
michael@0:                     colorMask[2],
michael@0:                     colorMask[3]);
michael@0: 
michael@0:     if (attrib0_enabled)
michael@0:         mGL->fEnableVertexAttribArray(0);
michael@0: 
michael@0:     mGL->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, attrib0_bufferBinding);
michael@0:     mGL->fVertexAttribPointer(0,
michael@0:                               attrib0_size,
michael@0:                               attrib0_type,
michael@0:                               attrib0_normalized,
michael@0:                               attrib0_stride,
michael@0:                               attrib0_pointer);
michael@0: 
michael@0:     mGL->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, boundBuffer);
michael@0: 
michael@0:     mGL->fUseProgram(boundProgram);
michael@0: }
michael@0: 
michael@0: void
michael@0: GLBlitHelper::BlitFramebufferToTexture(GLuint srcFB, GLuint destTex,
michael@0:                                     const gfx::IntSize& srcSize,
michael@0:                                     const gfx::IntSize& destSize,
michael@0:                                     GLenum destTarget)
michael@0: {
michael@0:     MOZ_ASSERT(!srcFB || mGL->fIsFramebuffer(srcFB));
michael@0:     MOZ_ASSERT(mGL->fIsTexture(destTex));
michael@0: 
michael@0:     if (mGL->IsSupported(GLFeature::framebuffer_blit)) {
michael@0:         ScopedFramebufferForTexture destWrapper(mGL, destTex, destTarget);
michael@0: 
michael@0:         BlitFramebufferToFramebuffer(srcFB, destWrapper.FB(),
michael@0:                                      srcSize, destSize);
michael@0:         return;
michael@0:     }
michael@0: 
michael@0:     ScopedBindTexture autoTex(mGL, destTex, destTarget);
michael@0:     ScopedBindFramebuffer boundFB(mGL, srcFB);
michael@0:     ScopedGLState scissor(mGL, LOCAL_GL_SCISSOR_TEST, false);
michael@0: 
michael@0:     mGL->fCopyTexSubImage2D(destTarget, 0,
michael@0:                        0, 0,
michael@0:                        0, 0,
michael@0:                        srcSize.width, srcSize.height);
michael@0: }
michael@0: 
michael@0: void
michael@0: GLBlitHelper::BlitTextureToTexture(GLuint srcTex, GLuint destTex,
michael@0:                                 const gfx::IntSize& srcSize,
michael@0:                                 const gfx::IntSize& destSize,
michael@0:                                 GLenum srcTarget, GLenum destTarget)
michael@0: {
michael@0:     MOZ_ASSERT(mGL->fIsTexture(srcTex));
michael@0:     MOZ_ASSERT(mGL->fIsTexture(destTex));
michael@0: 
michael@0:     // Generally, just use the CopyTexSubImage path
michael@0:     ScopedFramebufferForTexture srcWrapper(mGL, srcTex, srcTarget);
michael@0: 
michael@0:     BlitFramebufferToTexture(srcWrapper.FB(), destTex,
michael@0:                              srcSize, destSize, destTarget);
michael@0: }
michael@0: 
michael@0: }
michael@0: }