The Tor Browser: gfx/gl/GLReadTexImageHelper.cpp@97036ab72558 (annotated)

gfx/gl/GLReadTexImageHelper.cpp@97036ab72558 (annotated)

gfx/gl/GLReadTexImageHelper.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- 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 "GLContext.h"
 #include "OGLShaderProgram.h"
 #include "gfxTypes.h"
 #include "gfxContext.h"
 #include "gfxImageSurface.h"
 #include "ScopedGLHelpers.h"
 #include "mozilla/gfx/2D.h"
 #include "gfx2DGlue.h"
 using namespace mozilla::gfx;
 namespace mozilla {
 namespace gl {
 GLReadTexImageHelper::GLReadTexImageHelper(GLContext* gl)
     : mGL(gl)
 {
     mPrograms[0] = 0;
     mPrograms[1] = 0;
     mPrograms[2] = 0;
     mPrograms[3] = 0;
 }
 GLReadTexImageHelper::~GLReadTexImageHelper()
 {
     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;
 }
 static bool
 GetActualReadFormats(GLContext* gl,
                      GLenum destFormat, GLenum destType,
                      GLenum& readFormat, GLenum& readType)
 {
     if (destFormat == LOCAL_GL_RGBA &&
         destType == LOCAL_GL_UNSIGNED_BYTE)
     {
         readFormat = destFormat;
         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_INT_8_8_8_8_REV)
                     fallback = false;
                 break;
             }
         }
     }
     if (fallback) {
         readFormat = LOCAL_GL_RGBA;
         readType = LOCAL_GL_UNSIGNED_BYTE;
         return false;
     } else {
         readFormat = destFormat;
         readType = destType;
         return true;
     }
 }
 static void SwapRAndBComponents(DataSourceSurface* surf)
 {
   uint8_t *row = surf->GetData();
   if (!row) {
       MOZ_ASSERT(false, "SwapRAndBComponents: Failed to get data from DataSourceSurface.");
       return;
   }
   size_t rowBytes = surf->GetSize().width*4;
   size_t rowHole = surf->Stride() - rowBytes;
   size_t rows = surf->GetSize().height;
   while (rows) {
     const uint8_t *rowEnd = row + rowBytes;
     while (row != rowEnd) {
       row[0] ^= row[2];
       row[2] ^= row[0];
       row[0] ^= row[2];
       row += 4;
     }
     row += rowHole;
     --rows;
   }
 }
 static uint16_t PackRGB565(uint8_t r, uint8_t g, uint8_t b)
 {
     uint16_t pixel = ((r << 11) & 0xf800) |
                      ((g <<  5) & 0x07e0) |
                      ((b      ) & 0x001f);
     return pixel;
 }
 static void CopyDataSourceSurface(DataSourceSurface* aSource,
                                   DataSourceSurface* aDest)
 {
   MOZ_ASSERT(aSource->GetSize() == aDest->GetSize());
   MOZ_ASSERT(aSource->GetFormat() == SurfaceFormat::R8G8B8A8 ||
              aSource->GetFormat() == SurfaceFormat::R8G8B8X8);
   uint8_t *srcRow = aSource->GetData();
   size_t srcRowBytes = aSource->GetSize().width * BytesPerPixel(aSource->GetFormat());
   size_t srcRowHole = aSource->Stride() - srcRowBytes;
   uint8_t *destRow = aDest->GetData();
   size_t destRowBytes = aDest->GetSize().width * BytesPerPixel(aDest->GetFormat());
   size_t destRowHole = aDest->Stride() - destRowBytes;
   bool needsRBSwap = false;
   if (aDest->GetFormat() == SurfaceFormat::B8G8R8A8 ||
       aDest->GetFormat() == SurfaceFormat::B8G8R8X8 ||
       aDest->GetFormat() == SurfaceFormat::R5G6B5) {
       needsRBSwap = true;
   }
   bool needsConvertTo16Bits = false;
   if (aDest->GetFormat() == SurfaceFormat::R5G6B5) {
       needsConvertTo16Bits = true;
   }
   size_t rows = aSource->GetSize().height;
   while (rows) {
     const uint8_t *srcRowEnd = srcRow + srcRowBytes;
     while (srcRow != srcRowEnd) {
       uint8_t r = needsRBSwap ? srcRow[2] : srcRow[0];
       uint8_t g = srcRow[1];
       uint8_t b = needsRBSwap ? srcRow[0] : srcRow[2];
       uint8_t a = srcRow[3];
       if (needsConvertTo16Bits) {
         *(uint16_t*)destRow = PackRGB565(r, g, b);
       } else {
         destRow[0] = r;
         destRow[1] = g;
         destRow[2] = b;
         destRow[3] = a;
       }
       srcRow += BytesPerPixel(aSource->GetFormat());
       destRow += BytesPerPixel(aDest->GetFormat());
     }
     srcRow += srcRowHole;
     destRow += destRowHole;
     --rows;
   }
 }
 static int
 CalcStride(int width, int pixelSize, int alignment)
 {
     MOZ_ASSERT(alignment);
     int stride = width * pixelSize;
     if (stride % alignment) { // Extra at the end of the line?
         int alignmentCount = stride / alignment;
         stride = (alignmentCount+1) * alignment;
     }
     return stride;
 }
 static int
 GuessAlignment(int width, int pixelSize, int stride)
 {
     int alignment = 8; // Max GLES allows.
     while (CalcStride(width, pixelSize, alignment) != stride) {
         alignment /= 2;
         if (!alignment) {
             MOZ_ASSERT(alignment);
             return 1;
         }
     }
     return alignment;
 }
 void
 ReadPixelsIntoImageSurface(GLContext* gl, gfxImageSurface* dest) {
     gl->MakeCurrent();
     MOZ_ASSERT(dest->GetSize() != gfxIntSize(0, 0));
     /* gfxImageFormat::ARGB32:
      * RGBA+UByte:   be[RGBA], le[ABGR]
      * RGBA+UInt:    be[ABGR], le[RGBA]
      * BGRA+UInt:    be[ARGB], le[BGRA]
      * BGRA+UIntRev: be[BGRA], le[ARGB]
      *
      * gfxImageFormat::RGB16_565:
      * RGB+UShort: le[rrrrrggg,gggbbbbb]
      */
     bool hasAlpha = dest->Format() == gfxImageFormat::ARGB32;
     int destPixelSize;
     GLenum destFormat;
     GLenum destType;
     switch (dest->Format()) {
         case gfxImageFormat::RGB24: // XRGB
         case gfxImageFormat::ARGB32:
             destPixelSize = 4;
             // Needs host (little) endian ARGB.
             destFormat = LOCAL_GL_BGRA;
             destType = LOCAL_GL_UNSIGNED_INT_8_8_8_8_REV;
             break;
         case gfxImageFormat::RGB16_565:
             destPixelSize = 2;
             destFormat = LOCAL_GL_RGB;
             destType = LOCAL_GL_UNSIGNED_SHORT_5_6_5_REV;
             break;
         default:
             MOZ_CRASH("Bad format.");
     }
     MOZ_ASSERT(dest->Width() * destPixelSize <= dest->Stride());
     GLenum readFormat = destFormat;
     GLenum readType = destType;
     bool needsTempSurf = !GetActualReadFormats(gl,
                                                destFormat, destType,
                                                readFormat, readType);
     nsAutoPtr<gfxImageSurface> tempSurf;
     gfxImageSurface* readSurf = nullptr;
     int readAlignment = 0;
     if (needsTempSurf) {
         if (gl->DebugMode()) {
             NS_WARNING("Needing intermediary surface for ReadPixels. This will be slow!");
         }
         SurfaceFormat readFormatGFX;
         switch (readFormat) {
             case LOCAL_GL_RGBA:
             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;
                 break;
             }
             default: {
                 MOZ_CRASH("Bad 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("Bad read type.");
             }
         }
         tempSurf = new gfxImageSurface(dest->GetSize(),
                                        SurfaceFormatToImageFormat(readFormatGFX),
                                        false);
         readSurf = tempSurf;
     } else {
         // Figure out alignment. We don't need to know why, we just need it
         // to be valid.
         readAlignment = GuessAlignment(dest->Width(),
                                        destPixelSize,
                                        dest->Stride());
         readSurf = dest;
     }
     MOZ_ASSERT(readAlignment);
     GLint currentPackAlignment = 0;
     gl->fGetIntegerv(LOCAL_GL_PACK_ALIGNMENT, &currentPackAlignment);
     if (currentPackAlignment != readAlignment)
         gl->fPixelStorei(LOCAL_GL_PACK_ALIGNMENT, readAlignment);
     GLsizei width = dest->Width();
     GLsizei height = dest->Height();
     readSurf->Flush();
     gl->fReadPixels(0, 0,
                     width, height,
                     readFormat, readType,
                     readSurf->Data());
     readSurf->MarkDirty();
     if (currentPackAlignment != readAlignment)
         gl->fPixelStorei(LOCAL_GL_PACK_ALIGNMENT, currentPackAlignment);
     if (readSurf != dest) {
         MOZ_ASSERT(readFormat == LOCAL_GL_RGBA);
         MOZ_ASSERT(readType == LOCAL_GL_UNSIGNED_BYTE);
         // So we just copied in RGBA in big endian, or le: 0xAABBGGRR.
         // We want 0xAARRGGBB, so swap R and B:
         dest->Flush();
         RefPtr<DataSourceSurface> readDSurf =
             Factory::CreateWrappingDataSourceSurface(readSurf->Data(),
                                                      readSurf->Stride(),
                                                      ToIntSize(readSurf->GetSize()),
                                                      ImageFormatToSurfaceFormat(readSurf->Format()));
         SwapRAndBComponents(readDSurf);
         dest->MarkDirty();
         gfxContext ctx(dest);
         ctx.SetOperator(gfxContext::OPERATOR_SOURCE);
         ctx.SetSource(readSurf);
         ctx.Paint();
     }
     // Check if GL is giving back 1.0 alpha for
     // RGBA reads to RGBA images from no-alpha buffers.
 #ifdef XP_MACOSX
     if (gl->WorkAroundDriverBugs() &&
         gl->Vendor() == gl::GLVendor::NVIDIA &&
         dest->Format() == gfxImageFormat::ARGB32 &&
         width && height)
     {
         GLint alphaBits = 0;
         gl->fGetIntegerv(LOCAL_GL_ALPHA_BITS, &alphaBits);
         if (!alphaBits) {
             const uint32_t alphaMask = gfxPackedPixelNoPreMultiply(0xff,0,0,0);
             MOZ_ASSERT(dest->Width() * destPixelSize == dest->Stride());
             dest->Flush();
             uint32_t* itr = (uint32_t*)dest->Data();
             uint32_t testPixel = *itr;
             if ((testPixel & alphaMask) != alphaMask) {
                 // We need to set the alpha channel to 1.0 manually.
                 uint32_t* itrEnd = itr + width*height;  // Stride is guaranteed to be width*4.
                 for (; itr != itrEnd; itr++) {
                     *itr |= alphaMask;
                 }
             }
             dest->MarkDirty();
         }
     }
 #endif
 }
 void
 ReadPixelsIntoDataSourceSurface(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:
             destFormat = LOCAL_GL_RGB;
             destType = LOCAL_GL_UNSIGNED_SHORT_5_6_5_REV;
             break;
         default:
             MOZ_CRASH("Bad format.");
     }
     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 = nullptr;
     int readAlignment = 0;
     if (needsTempSurf) {
         if (gl->DebugMode()) {
             NS_WARNING("Needing intermediary surface for ReadPixels. This will be slow!");
         }
         SurfaceFormat readFormatGFX;
         // If needs temp surface, readFormat is always LOCAL_GL_RGBA
         // and readType is always LOCAL_GL_UNSIGNED_BYTE
         MOZ_ASSERT(readFormat == LOCAL_GL_RGBA);
         MOZ_ASSERT(readType == LOCAL_GL_UNSIGNED_BYTE);
         readFormatGFX = hasAlpha ? SurfaceFormat::R8G8B8A8
                                  : SurfaceFormat::R8G8B8X8;
         readAlignment = 1;
         int32_t stride = dest->GetSize().width * BytesPerPixel(readFormatGFX);
         tempSurf = Factory::CreateDataSourceSurfaceWithStride(dest->GetSize(),
                                                               readFormatGFX,
                                                               stride);
         readSurf = tempSurf;
     } else {
         // Figure out alignment. We don't need to know why, we just need it
         // to be valid.
         readAlignment = GuessAlignment(dest->GetSize().width,
                                        destPixelSize,
                                        dest->Stride());
         readSurf = dest;
     }
     MOZ_ASSERT(readAlignment);
     MOZ_ASSERT(reinterpret_cast<uintptr_t>(readSurf->GetData()) % readAlignment == 0);
     GLint currentPackAlignment = 0;
     gl->fGetIntegerv(LOCAL_GL_PACK_ALIGNMENT, &currentPackAlignment);
     if (currentPackAlignment != readAlignment)
         gl->fPixelStorei(LOCAL_GL_PACK_ALIGNMENT, readAlignment);
     GLsizei width = dest->GetSize().width;
     GLsizei height = dest->GetSize().height;
     gl->fReadPixels(0, 0,
                     width, height,
                     readFormat, readType,
                     readSurf->GetData());
     if (currentPackAlignment != readAlignment)
         gl->fPixelStorei(LOCAL_GL_PACK_ALIGNMENT, currentPackAlignment);
     if (readSurf != dest) {
         MOZ_ASSERT(readFormat == LOCAL_GL_RGBA);
         MOZ_ASSERT(readType == LOCAL_GL_UNSIGNED_BYTE);
         CopyDataSourceSurface(readSurf, dest);
     }
     // Check if GL is giving back 1.0 alpha for
     // RGBA reads to RGBA images from no-alpha buffers.
 #ifdef XP_MACOSX
     if (gl->WorkAroundDriverBugs() &&
         gl->Vendor() == gl::GLVendor::NVIDIA &&
         (dest->GetFormat() == SurfaceFormat::R8G8B8A8 ||
          dest->GetFormat() == SurfaceFormat::B8G8R8A8) &&
         width && height)
     {
         GLint alphaBits = 0;
         gl->fGetIntegerv(LOCAL_GL_ALPHA_BITS, &alphaBits);
         if (!alphaBits) {
             const uint32_t alphaMask = gfxPackedPixelNoPreMultiply(0xff,0,0,0);
             MOZ_ASSERT(dest->GetSize().width * destPixelSize == dest->Stride());
             uint32_t* itr = (uint32_t*)dest->GetData();
             uint32_t testPixel = *itr;
             if ((testPixel & alphaMask) != alphaMask) {
                 // We need to set the alpha channel to 1.0 manually.
                 uint32_t* itrEnd = itr + width*height;  // Stride is guaranteed to be width*4.
                 for (; itr != itrEnd; itr++) {
                     *itr |= alphaMask;
                 }
             }
         }
     }
 #endif
 }
 static TemporaryRef<DataSourceSurface> YInvertImageSurface(DataSourceSurface* aSurf)
 {
   RefPtr<DataSourceSurface> temp =
     Factory::CreateDataSourceSurfaceWithStride(aSurf->GetSize(),
                                                aSurf->GetFormat(),
                                                aSurf->Stride());
   RefPtr<DrawTarget> dt =
     Factory::CreateDrawTargetForData(BackendType::CAIRO,
                                      temp->GetData(),
                                      temp->GetSize(),
                                      temp->Stride(),
                                      temp->GetFormat());
   nsRefPtr<gfxContext> ctx = new gfxContext(dt);
   ctx->SetOperator(gfxContext::OPERATOR_SOURCE);
   ctx->Scale(1.0, -1.0);
   ctx->Translate(-gfxPoint(0.0, aSurf->GetSize().height));
   nsRefPtr<gfxImageSurface> thebesSurf =
     new gfxImageSurface(aSurf->GetData(),
                         ThebesIntSize(aSurf->GetSize()),
                         aSurf->Stride(),
                         SurfaceFormatToImageFormat(aSurf->GetFormat()));
   ctx->SetSource(thebesSurf);
   ctx->Paint();
   return temp.forget();
 }
 TemporaryRef<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 (!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();
 }
 void
 ReadScreenIntoImageSurface(GLContext* gl, gfxImageSurface* dest)
 {
     ScopedBindFramebuffer autoFB(gl, 0);
     ReadPixelsIntoImageSurface(gl, dest);
 }
 #define CLEANUP_IF_GLERROR_OCCURRED(x)                                      \
     if (DidGLErrorOccur(x)) {                                               \
         isurf = nullptr;                                                    \
         break;                                                              \
     }
 TemporaryRef<DataSourceSurface>
 GLReadTexImageHelper::ReadTexImage(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();
     /* Allocate resulting image surface */
     int32_t stride = aSize.width * BytesPerPixel(SurfaceFormat::R8G8B8A8);
     RefPtr<DataSourceSurface> isurf =
         Factory::CreateDataSourceSurfaceWithStride(aSize,
                                                    SurfaceFormat::R8G8B8A8,
                                                    stride);
     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);
         mGL->fEnableVertexAttribArray(0);
         mGL->fEnableVertexAttribArray(1);
         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,
 .0f, -1.0f,
             -1.0f,  1.0f,
 .0f,  1.0f
          };
         mGL->fVertexAttribPointer(0, 2, LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 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 };
         mGL->fVertexAttribPointer(1, 2, LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 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");
         mGL->fDisableVertexAttribArray(1);
         mGL->fDisableVertexAttribArray(0);
         /* Read-back draw results */
         ReadPixelsIntoDataSourceSurface(mGL, isurf);
         CLEANUP_IF_GLERROR_OCCURRED("when reading pixels into surface");
     } while (false);
     /* Restore GL state */
 //cleanup:
     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 isurf.forget();
 }
 #undef CLEANUP_IF_GLERROR_OCCURRED
 }
 }

The Tor Browser / annotate

gfx/gl/GLReadTexImageHelper.cpp@97036ab72558 (annotated)

gfx/gl/GLReadTexImageHelper.cpp