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-rw-r--r--gfx/gl/GLReadTexImageHelper.cpp659
1 files changed, 659 insertions, 0 deletions
diff --git a/gfx/gl/GLReadTexImageHelper.cpp b/gfx/gl/GLReadTexImageHelper.cpp
new file mode 100644
index 000000000..659378228
--- /dev/null
+++ b/gfx/gl/GLReadTexImageHelper.cpp
@@ -0,0 +1,659 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim: set ts=8 sts=4 et sw=4 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GLReadTexImageHelper.h"
+
+#include "gfx2DGlue.h"
+#include "gfxColor.h"
+#include "gfxTypes.h"
+#include "GLContext.h"
+#include "OGLShaderProgram.h"
+#include "ScopedGLHelpers.h"
+
+#include "mozilla/gfx/2D.h"
+#include "mozilla/Move.h"
+
+namespace mozilla {
+namespace gl {
+
+using namespace mozilla::gfx;
+
+GLReadTexImageHelper::GLReadTexImageHelper(GLContext* gl)
+ : mGL(gl)
+{
+ mPrograms[0] = 0;
+ mPrograms[1] = 0;
+ mPrograms[2] = 0;
+ mPrograms[3] = 0;
+}
+
+GLReadTexImageHelper::~GLReadTexImageHelper()
+{
+ if (!mGL->MakeCurrent())
+ return;
+
+ mGL->fDeleteProgram(mPrograms[0]);
+ mGL->fDeleteProgram(mPrograms[1]);
+ mGL->fDeleteProgram(mPrograms[2]);
+ mGL->fDeleteProgram(mPrograms[3]);
+}
+
+static const GLchar
+readTextureImageVS[] =
+ "attribute vec2 aVertex;\n"
+ "attribute vec2 aTexCoord;\n"
+ "varying vec2 vTexCoord;\n"
+ "void main() { gl_Position = vec4(aVertex, 0, 1); vTexCoord = aTexCoord; }";
+
+static const GLchar
+readTextureImageFS_TEXTURE_2D[] =
+ "#ifdef GL_ES\n"
+ "precision mediump float;\n"
+ "#endif\n"
+ "varying vec2 vTexCoord;\n"
+ "uniform sampler2D uTexture;\n"
+ "void main() { gl_FragColor = texture2D(uTexture, vTexCoord); }";
+
+
+static const GLchar
+readTextureImageFS_TEXTURE_2D_BGRA[] =
+ "#ifdef GL_ES\n"
+ "precision mediump float;\n"
+ "#endif\n"
+ "varying vec2 vTexCoord;\n"
+ "uniform sampler2D uTexture;\n"
+ "void main() { gl_FragColor = texture2D(uTexture, vTexCoord).bgra; }";
+
+static const GLchar
+readTextureImageFS_TEXTURE_EXTERNAL[] =
+ "#extension GL_OES_EGL_image_external : require\n"
+ "#ifdef GL_ES\n"
+ "precision mediump float;\n"
+ "#endif\n"
+ "varying vec2 vTexCoord;\n"
+ "uniform samplerExternalOES uTexture;\n"
+ "void main() { gl_FragColor = texture2D(uTexture, vTexCoord); }";
+
+static const GLchar
+readTextureImageFS_TEXTURE_RECTANGLE[] =
+ "#extension GL_ARB_texture_rectangle\n"
+ "#ifdef GL_ES\n"
+ "precision mediump float;\n"
+ "#endif\n"
+ "varying vec2 vTexCoord;\n"
+ "uniform sampler2DRect uTexture;\n"
+ "void main() { gl_FragColor = texture2DRect(uTexture, vTexCoord).bgra; }";
+
+GLuint
+GLReadTexImageHelper::TextureImageProgramFor(GLenum aTextureTarget,
+ int aConfig)
+{
+ int variant = 0;
+ const GLchar* readTextureImageFS = nullptr;
+ if (aTextureTarget == LOCAL_GL_TEXTURE_2D) {
+ if (aConfig & mozilla::layers::ENABLE_TEXTURE_RB_SWAP) {
+ // Need to swizzle R/B.
+ readTextureImageFS = readTextureImageFS_TEXTURE_2D_BGRA;
+ variant = 1;
+ } else {
+ readTextureImageFS = readTextureImageFS_TEXTURE_2D;
+ variant = 0;
+ }
+ } else if (aTextureTarget == LOCAL_GL_TEXTURE_EXTERNAL) {
+ readTextureImageFS = readTextureImageFS_TEXTURE_EXTERNAL;
+ variant = 2;
+ } else if (aTextureTarget == LOCAL_GL_TEXTURE_RECTANGLE) {
+ readTextureImageFS = readTextureImageFS_TEXTURE_RECTANGLE;
+ variant = 3;
+ }
+
+ /* This might be overkill, but assure that we don't access out-of-bounds */
+ MOZ_ASSERT((size_t) variant < ArrayLength(mPrograms));
+ if (!mPrograms[variant]) {
+ GLuint vs = mGL->fCreateShader(LOCAL_GL_VERTEX_SHADER);
+ const GLchar* vsSourcePtr = &readTextureImageVS[0];
+ mGL->fShaderSource(vs, 1, &vsSourcePtr, nullptr);
+ mGL->fCompileShader(vs);
+
+ GLuint fs = mGL->fCreateShader(LOCAL_GL_FRAGMENT_SHADER);
+ mGL->fShaderSource(fs, 1, &readTextureImageFS, nullptr);
+ mGL->fCompileShader(fs);
+
+ GLuint program = mGL->fCreateProgram();
+ mGL->fAttachShader(program, vs);
+ mGL->fAttachShader(program, fs);
+ mGL->fBindAttribLocation(program, 0, "aVertex");
+ mGL->fBindAttribLocation(program, 1, "aTexCoord");
+ mGL->fLinkProgram(program);
+
+ GLint success;
+ mGL->fGetProgramiv(program, LOCAL_GL_LINK_STATUS, &success);
+
+ if (!success) {
+ mGL->fDeleteProgram(program);
+ program = 0;
+ }
+
+ mGL->fDeleteShader(vs);
+ mGL->fDeleteShader(fs);
+
+ mPrograms[variant] = program;
+ }
+
+ return mPrograms[variant];
+}
+
+bool
+GLReadTexImageHelper::DidGLErrorOccur(const char* str)
+{
+ GLenum error = mGL->fGetError();
+ if (error != LOCAL_GL_NO_ERROR) {
+ printf_stderr("GL ERROR: %s (0x%04x) %s\n",
+ mGL->GLErrorToString(error), error, str);
+ return true;
+ }
+
+ return false;
+}
+
+bool
+GetActualReadFormats(GLContext* gl,
+ GLenum destFormat, GLenum destType,
+ GLenum* out_readFormat, GLenum* out_readType)
+{
+ MOZ_ASSERT(out_readFormat);
+ MOZ_ASSERT(out_readType);
+
+ if (destFormat == LOCAL_GL_RGBA &&
+ destType == LOCAL_GL_UNSIGNED_BYTE)
+ {
+ *out_readFormat = destFormat;
+ *out_readType = destType;
+ return true;
+ }
+
+ bool fallback = true;
+ if (gl->IsGLES()) {
+ GLenum auxFormat = 0;
+ GLenum auxType = 0;
+
+ gl->fGetIntegerv(LOCAL_GL_IMPLEMENTATION_COLOR_READ_FORMAT, (GLint*)&auxFormat);
+ gl->fGetIntegerv(LOCAL_GL_IMPLEMENTATION_COLOR_READ_TYPE, (GLint*)&auxType);
+
+ if (destFormat == auxFormat &&
+ destType == auxType)
+ {
+ fallback = false;
+ }
+ } else {
+ switch (destFormat) {
+ case LOCAL_GL_RGB: {
+ if (destType == LOCAL_GL_UNSIGNED_SHORT_5_6_5_REV)
+ fallback = false;
+ break;
+ }
+ case LOCAL_GL_BGRA: {
+ if (destType == LOCAL_GL_UNSIGNED_BYTE ||
+ destType == LOCAL_GL_UNSIGNED_INT_8_8_8_8_REV)
+ {
+ fallback = false;
+ }
+ break;
+ }
+ }
+ }
+
+ if (fallback) {
+ *out_readFormat = LOCAL_GL_RGBA;
+ *out_readType = LOCAL_GL_UNSIGNED_BYTE;
+ return false;
+ } else {
+ *out_readFormat = destFormat;
+ *out_readType = destType;
+ return true;
+ }
+}
+
+void
+SwapRAndBComponents(DataSourceSurface* surf)
+{
+ DataSourceSurface::MappedSurface map;
+ if (!surf->Map(DataSourceSurface::MapType::READ_WRITE, &map)) {
+ MOZ_ASSERT(false, "SwapRAndBComponents: Failed to map surface.");
+ return;
+ }
+ MOZ_ASSERT(map.mStride >= 0);
+
+ const size_t rowBytes = surf->GetSize().width*4;
+ const size_t rowHole = map.mStride - rowBytes;
+
+ uint8_t* row = map.mData;
+ if (!row) {
+ MOZ_ASSERT(false, "SwapRAndBComponents: Failed to get data from"
+ " DataSourceSurface.");
+ surf->Unmap();
+ return;
+ }
+
+ const size_t rows = surf->GetSize().height;
+ for (size_t i = 0; i < rows; i++) {
+ const uint8_t* rowEnd = row + rowBytes;
+
+ while (row != rowEnd) {
+ Swap(row[0], row[2]);
+ row += 4;
+ }
+
+ row += rowHole;
+ }
+
+ surf->Unmap();
+}
+
+static int
+CalcRowStride(int width, int pixelSize, int alignment)
+{
+ MOZ_ASSERT(alignment);
+
+ int rowStride = width * pixelSize;
+ if (rowStride % alignment) { // Extra at the end of the line?
+ int alignmentCount = rowStride / alignment;
+ rowStride = (alignmentCount+1) * alignment;
+ }
+ return rowStride;
+}
+
+static int
+GuessAlignment(int width, int pixelSize, int rowStride)
+{
+ int alignment = 8; // Max GLES allows.
+ while (CalcRowStride(width, pixelSize, alignment) != rowStride) {
+ alignment /= 2;
+ if (!alignment) {
+ NS_WARNING("Bad alignment for GLES. Will use temp surf for readback.");
+ return 0;
+ }
+ }
+ return alignment;
+}
+
+void
+ReadPixelsIntoDataSurface(GLContext* gl, DataSourceSurface* dest)
+{
+ gl->MakeCurrent();
+ MOZ_ASSERT(dest->GetSize().width != 0);
+ MOZ_ASSERT(dest->GetSize().height != 0);
+
+ bool hasAlpha = dest->GetFormat() == SurfaceFormat::B8G8R8A8 ||
+ dest->GetFormat() == SurfaceFormat::R8G8B8A8;
+
+ int destPixelSize;
+ GLenum destFormat;
+ GLenum destType;
+
+ switch (dest->GetFormat()) {
+ case SurfaceFormat::B8G8R8A8:
+ case SurfaceFormat::B8G8R8X8:
+ // Needs host (little) endian ARGB.
+ destFormat = LOCAL_GL_BGRA;
+ destType = LOCAL_GL_UNSIGNED_INT_8_8_8_8_REV;
+ break;
+ case SurfaceFormat::R8G8B8A8:
+ case SurfaceFormat::R8G8B8X8:
+ // Needs host (little) endian ABGR.
+ destFormat = LOCAL_GL_RGBA;
+ destType = LOCAL_GL_UNSIGNED_BYTE;
+ break;
+ case SurfaceFormat::R5G6B5_UINT16:
+ destFormat = LOCAL_GL_RGB;
+ destType = LOCAL_GL_UNSIGNED_SHORT_5_6_5_REV;
+ break;
+ default:
+ MOZ_CRASH("GFX: Bad format, read pixels.");
+ }
+ destPixelSize = BytesPerPixel(dest->GetFormat());
+ MOZ_ASSERT(dest->GetSize().width * destPixelSize <= dest->Stride());
+
+ GLenum readFormat = destFormat;
+ GLenum readType = destType;
+ bool needsTempSurf = !GetActualReadFormats(gl,
+ destFormat, destType,
+ &readFormat, &readType);
+
+ RefPtr<DataSourceSurface> tempSurf;
+ DataSourceSurface* readSurf = dest;
+ int readAlignment = GuessAlignment(dest->GetSize().width,
+ destPixelSize,
+ dest->Stride());
+ if (!readAlignment) {
+ needsTempSurf = true;
+ }
+ if (needsTempSurf) {
+ if (GLContext::ShouldSpew()) {
+ NS_WARNING("Needing intermediary surface for ReadPixels. This will be slow!");
+ }
+ SurfaceFormat readFormatGFX;
+
+ switch (readFormat) {
+ case LOCAL_GL_RGBA: {
+ readFormatGFX = hasAlpha ? SurfaceFormat::R8G8B8A8
+ : SurfaceFormat::R8G8B8X8;
+ break;
+ }
+ case LOCAL_GL_BGRA: {
+ readFormatGFX = hasAlpha ? SurfaceFormat::B8G8R8A8
+ : SurfaceFormat::B8G8R8X8;
+ break;
+ }
+ case LOCAL_GL_RGB: {
+ MOZ_ASSERT(destPixelSize == 2);
+ MOZ_ASSERT(readType == LOCAL_GL_UNSIGNED_SHORT_5_6_5_REV);
+ readFormatGFX = SurfaceFormat::R5G6B5_UINT16;
+ break;
+ }
+ default: {
+ MOZ_CRASH("GFX: Bad read format, read format.");
+ }
+ }
+
+ switch (readType) {
+ case LOCAL_GL_UNSIGNED_BYTE: {
+ MOZ_ASSERT(readFormat == LOCAL_GL_RGBA);
+ readAlignment = 1;
+ break;
+ }
+ case LOCAL_GL_UNSIGNED_INT_8_8_8_8_REV: {
+ MOZ_ASSERT(readFormat == LOCAL_GL_BGRA);
+ readAlignment = 4;
+ break;
+ }
+ case LOCAL_GL_UNSIGNED_SHORT_5_6_5_REV: {
+ MOZ_ASSERT(readFormat == LOCAL_GL_RGB);
+ readAlignment = 2;
+ break;
+ }
+ default: {
+ MOZ_CRASH("GFX: Bad read type, read type.");
+ }
+ }
+
+ int32_t stride = dest->GetSize().width * BytesPerPixel(readFormatGFX);
+ tempSurf = Factory::CreateDataSourceSurfaceWithStride(dest->GetSize(),
+ readFormatGFX,
+ stride);
+ if (NS_WARN_IF(!tempSurf)) {
+ return;
+ }
+
+ readSurf = tempSurf;
+ }
+ MOZ_ASSERT(readAlignment);
+ MOZ_ASSERT(reinterpret_cast<uintptr_t>(readSurf->GetData()) % readAlignment == 0);
+
+ GLsizei width = dest->GetSize().width;
+ GLsizei height = dest->GetSize().height;
+
+ {
+ ScopedPackState safePackState(gl);
+ gl->fPixelStorei(LOCAL_GL_PACK_ALIGNMENT, readAlignment);
+
+ gl->fReadPixels(0, 0,
+ width, height,
+ readFormat, readType,
+ readSurf->GetData());
+ }
+
+ if (readSurf != dest) {
+ MOZ_ASSERT(readFormat == LOCAL_GL_RGBA);
+ MOZ_ASSERT(readType == LOCAL_GL_UNSIGNED_BYTE);
+ gfx::Factory::CopyDataSourceSurface(readSurf, dest);
+ }
+}
+
+already_AddRefed<gfx::DataSourceSurface>
+YInvertImageSurface(gfx::DataSourceSurface* aSurf)
+{
+ RefPtr<DataSourceSurface> temp =
+ Factory::CreateDataSourceSurfaceWithStride(aSurf->GetSize(),
+ aSurf->GetFormat(),
+ aSurf->Stride());
+ if (NS_WARN_IF(!temp)) {
+ return nullptr;
+ }
+
+ DataSourceSurface::MappedSurface map;
+ if (!temp->Map(DataSourceSurface::MapType::WRITE, &map)) {
+ return nullptr;
+ }
+
+ RefPtr<DrawTarget> dt =
+ Factory::CreateDrawTargetForData(BackendType::CAIRO,
+ map.mData,
+ temp->GetSize(),
+ map.mStride,
+ temp->GetFormat());
+ if (!dt) {
+ temp->Unmap();
+ return nullptr;
+ }
+
+ dt->SetTransform(Matrix::Scaling(1.0, -1.0) *
+ Matrix::Translation(0.0, aSurf->GetSize().height));
+ Rect rect(0, 0, aSurf->GetSize().width, aSurf->GetSize().height);
+ dt->DrawSurface(aSurf, rect, rect, DrawSurfaceOptions(),
+ DrawOptions(1.0, CompositionOp::OP_SOURCE, AntialiasMode::NONE));
+ temp->Unmap();
+ return temp.forget();
+}
+
+already_AddRefed<DataSourceSurface>
+ReadBackSurface(GLContext* gl, GLuint aTexture, bool aYInvert, SurfaceFormat aFormat)
+{
+ gl->MakeCurrent();
+ gl->GuaranteeResolve();
+ gl->fActiveTexture(LOCAL_GL_TEXTURE0);
+ gl->fBindTexture(LOCAL_GL_TEXTURE_2D, aTexture);
+
+ IntSize size;
+ gl->fGetTexLevelParameteriv(LOCAL_GL_TEXTURE_2D, 0, LOCAL_GL_TEXTURE_WIDTH, &size.width);
+ gl->fGetTexLevelParameteriv(LOCAL_GL_TEXTURE_2D, 0, LOCAL_GL_TEXTURE_HEIGHT, &size.height);
+
+ RefPtr<DataSourceSurface> surf =
+ Factory::CreateDataSourceSurfaceWithStride(size, SurfaceFormat::B8G8R8A8,
+ GetAlignedStride<4>(size.width, BytesPerPixel(SurfaceFormat::B8G8R8A8)));
+
+ if (NS_WARN_IF(!surf)) {
+ return nullptr;
+ }
+
+ uint32_t currentPackAlignment = 0;
+ gl->fGetIntegerv(LOCAL_GL_PACK_ALIGNMENT, (GLint*)&currentPackAlignment);
+ if (currentPackAlignment != 4) {
+ gl->fPixelStorei(LOCAL_GL_PACK_ALIGNMENT, 4);
+ }
+
+ gl->fGetTexImage(LOCAL_GL_TEXTURE_2D, 0, LOCAL_GL_RGBA, LOCAL_GL_UNSIGNED_BYTE, surf->GetData());
+
+ if (currentPackAlignment != 4) {
+ gl->fPixelStorei(LOCAL_GL_PACK_ALIGNMENT, currentPackAlignment);
+ }
+
+ if (aFormat == SurfaceFormat::R8G8B8A8 || aFormat == SurfaceFormat::R8G8B8X8) {
+ SwapRAndBComponents(surf);
+ }
+
+ if (aYInvert) {
+ surf = YInvertImageSurface(surf);
+ }
+
+ return surf.forget();
+}
+
+#define CLEANUP_IF_GLERROR_OCCURRED(x) \
+ if (DidGLErrorOccur(x)) { \
+ return false; \
+ }
+
+already_AddRefed<DataSourceSurface>
+GLReadTexImageHelper::ReadTexImage(GLuint aTextureId,
+ GLenum aTextureTarget,
+ const gfx::IntSize& aSize,
+ /* ShaderConfigOGL.mFeature */ int aConfig,
+ bool aYInvert)
+{
+ /* Allocate resulting image surface */
+ int32_t stride = aSize.width * BytesPerPixel(SurfaceFormat::R8G8B8A8);
+ RefPtr<DataSourceSurface> isurf =
+ Factory::CreateDataSourceSurfaceWithStride(aSize,
+ SurfaceFormat::R8G8B8A8,
+ stride);
+ if (NS_WARN_IF(!isurf)) {
+ return nullptr;
+ }
+
+ if (!ReadTexImage(isurf, aTextureId, aTextureTarget, aSize, aConfig, aYInvert)) {
+ return nullptr;
+ }
+
+ return isurf.forget();
+}
+
+bool
+GLReadTexImageHelper::ReadTexImage(DataSourceSurface* aDest,
+ GLuint aTextureId,
+ GLenum aTextureTarget,
+ const gfx::IntSize& aSize,
+ /* ShaderConfigOGL.mFeature */ int aConfig,
+ bool aYInvert)
+{
+ MOZ_ASSERT(aTextureTarget == LOCAL_GL_TEXTURE_2D ||
+ aTextureTarget == LOCAL_GL_TEXTURE_EXTERNAL ||
+ aTextureTarget == LOCAL_GL_TEXTURE_RECTANGLE_ARB);
+
+ mGL->MakeCurrent();
+
+ GLint oldrb, oldfb, oldprog, oldTexUnit, oldTex;
+ GLuint rb, fb;
+
+ do {
+ mGL->fGetIntegerv(LOCAL_GL_RENDERBUFFER_BINDING, &oldrb);
+ mGL->fGetIntegerv(LOCAL_GL_FRAMEBUFFER_BINDING, &oldfb);
+ mGL->fGetIntegerv(LOCAL_GL_CURRENT_PROGRAM, &oldprog);
+ mGL->fGetIntegerv(LOCAL_GL_ACTIVE_TEXTURE, &oldTexUnit);
+ mGL->fActiveTexture(LOCAL_GL_TEXTURE0);
+ switch (aTextureTarget) {
+ case LOCAL_GL_TEXTURE_2D:
+ mGL->fGetIntegerv(LOCAL_GL_TEXTURE_BINDING_2D, &oldTex);
+ break;
+ case LOCAL_GL_TEXTURE_EXTERNAL:
+ mGL->fGetIntegerv(LOCAL_GL_TEXTURE_BINDING_EXTERNAL, &oldTex);
+ break;
+ case LOCAL_GL_TEXTURE_RECTANGLE:
+ mGL->fGetIntegerv(LOCAL_GL_TEXTURE_BINDING_RECTANGLE, &oldTex);
+ break;
+ default: /* Already checked above */
+ break;
+ }
+
+ ScopedGLState scopedScissorTestState(mGL, LOCAL_GL_SCISSOR_TEST, false);
+ ScopedGLState scopedBlendState(mGL, LOCAL_GL_BLEND, false);
+ ScopedViewportRect scopedViewportRect(mGL, 0, 0, aSize.width, aSize.height);
+
+ /* Setup renderbuffer */
+ mGL->fGenRenderbuffers(1, &rb);
+ mGL->fBindRenderbuffer(LOCAL_GL_RENDERBUFFER, rb);
+
+ GLenum rbInternalFormat =
+ mGL->IsGLES()
+ ? (mGL->IsExtensionSupported(GLContext::OES_rgb8_rgba8) ? LOCAL_GL_RGBA8 : LOCAL_GL_RGBA4)
+ : LOCAL_GL_RGBA;
+ mGL->fRenderbufferStorage(LOCAL_GL_RENDERBUFFER, rbInternalFormat, aSize.width, aSize.height);
+ CLEANUP_IF_GLERROR_OCCURRED("when binding and creating renderbuffer");
+
+ /* Setup framebuffer */
+ mGL->fGenFramebuffers(1, &fb);
+ mGL->fBindFramebuffer(LOCAL_GL_FRAMEBUFFER, fb);
+ mGL->fFramebufferRenderbuffer(LOCAL_GL_FRAMEBUFFER, LOCAL_GL_COLOR_ATTACHMENT0,
+ LOCAL_GL_RENDERBUFFER, rb);
+ CLEANUP_IF_GLERROR_OCCURRED("when binding and creating framebuffer");
+
+ MOZ_ASSERT(mGL->fCheckFramebufferStatus(LOCAL_GL_FRAMEBUFFER) == LOCAL_GL_FRAMEBUFFER_COMPLETE);
+
+ /* Setup vertex and fragment shader */
+ GLuint program = TextureImageProgramFor(aTextureTarget, aConfig);
+ MOZ_ASSERT(program);
+
+ mGL->fUseProgram(program);
+ CLEANUP_IF_GLERROR_OCCURRED("when using program");
+ mGL->fUniform1i(mGL->fGetUniformLocation(program, "uTexture"), 0);
+ CLEANUP_IF_GLERROR_OCCURRED("when setting uniform location");
+
+ /* Setup quad geometry */
+ mGL->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, 0);
+
+ float w = (aTextureTarget == LOCAL_GL_TEXTURE_RECTANGLE) ? (float) aSize.width : 1.0f;
+ float h = (aTextureTarget == LOCAL_GL_TEXTURE_RECTANGLE) ? (float) aSize.height : 1.0f;
+
+ const float
+ vertexArray[4*2] = {
+ -1.0f, -1.0f,
+ 1.0f, -1.0f,
+ -1.0f, 1.0f,
+ 1.0f, 1.0f
+ };
+ ScopedVertexAttribPointer autoAttrib0(mGL, 0, 2, LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0, 0, vertexArray);
+
+ const float u0 = 0.0f;
+ const float u1 = w;
+ const float v0 = aYInvert ? h : 0.0f;
+ const float v1 = aYInvert ? 0.0f : h;
+ const float texCoordArray[8] = { u0, v0,
+ u1, v0,
+ u0, v1,
+ u1, v1 };
+ ScopedVertexAttribPointer autoAttrib1(mGL, 1, 2, LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0, 0, texCoordArray);
+
+ /* Bind the texture */
+ if (aTextureId) {
+ mGL->fBindTexture(aTextureTarget, aTextureId);
+ CLEANUP_IF_GLERROR_OCCURRED("when binding texture");
+ }
+
+ /* Draw quad */
+ mGL->fClearColor(1.0f, 0.0f, 1.0f, 1.0f);
+ mGL->fClear(LOCAL_GL_COLOR_BUFFER_BIT);
+ CLEANUP_IF_GLERROR_OCCURRED("when clearing color buffer");
+
+ mGL->fDrawArrays(LOCAL_GL_TRIANGLE_STRIP, 0, 4);
+ CLEANUP_IF_GLERROR_OCCURRED("when drawing texture");
+
+ /* Read-back draw results */
+ ReadPixelsIntoDataSurface(mGL, aDest);
+ CLEANUP_IF_GLERROR_OCCURRED("when reading pixels into surface");
+ } while (false);
+
+ /* Restore GL state */
+ mGL->fBindRenderbuffer(LOCAL_GL_RENDERBUFFER, oldrb);
+ mGL->fBindFramebuffer(LOCAL_GL_FRAMEBUFFER, oldfb);
+ mGL->fUseProgram(oldprog);
+
+ // note that deleting 0 has no effect in any of these calls
+ mGL->fDeleteRenderbuffers(1, &rb);
+ mGL->fDeleteFramebuffers(1, &fb);
+
+ if (aTextureId)
+ mGL->fBindTexture(aTextureTarget, oldTex);
+
+ if (oldTexUnit != LOCAL_GL_TEXTURE0)
+ mGL->fActiveTexture(oldTexUnit);
+
+ return true;
+}
+
+#undef CLEANUP_IF_GLERROR_OCCURRED
+
+} // namespace gl
+} // namespace mozilla