C++ ShaderProgramOGL::SetTextureUnit方法代码示例

void
ShadowCanvasLayerOGL::RenderLayer(int aPreviousFrameBuffer,
                                  const nsIntPoint& aOffset)
{
  mOGLManager->MakeCurrent();

  ShaderProgramOGL *program =
    mOGLManager->GetProgram(mTexImage->GetShaderProgramType(),
                            GetMaskLayer());


  gfx3DMatrix effectiveTransform = GetEffectiveTransform();
#ifdef ANDROID
  // Bug 691354
  // Using the LINEAR filter we get unexplained artifacts.
  // Use NEAREST when no scaling is required.
  gfxMatrix matrix;
  bool is2D = GetEffectiveTransform().Is2D(&matrix);
  if (is2D && !matrix.HasNonTranslationOrFlip()) {
    mTexImage->SetFilter(gfxPattern::FILTER_NEAREST);
  } else {
    mTexImage->SetFilter(mFilter);
  }
#else
  mTexImage->SetFilter(mFilter);
#endif


  program->Activate();
  program->SetLayerTransform(effectiveTransform);
  program->SetLayerOpacity(GetEffectiveOpacity());
  program->SetRenderOffset(aOffset);
  program->SetTextureUnit(0);
  program->LoadMask(GetMaskLayer());

  mTexImage->BeginTileIteration();
  if (gl()->CanUploadNonPowerOfTwo()) {
    do {
      TextureImage::ScopedBindTextureAndApplyFilter texBind(mTexImage, LOCAL_GL_TEXTURE0);
      program->SetLayerQuadRect(mTexImage->GetTileRect());
      mOGLManager->BindAndDrawQuad(program, mNeedsYFlip); // FIXME flip order of tiles?
    } while (mTexImage->NextTile());
  } else {
    do {
      TextureImage::ScopedBindTextureAndApplyFilter texBind(mTexImage, LOCAL_GL_TEXTURE0);
      program->SetLayerQuadRect(mTexImage->GetTileRect());
      // We can't use BindAndDrawQuad because that always uploads the whole texture from 0.0f -> 1.0f
      // in x and y. We use BindAndDrawQuadWithTextureRect to actually draw a subrect of the texture
      // We need to reset the origin to 0,0 from the tile rect because the tile originates at 0,0 in the
      // actual texture, even though its origin in the composed (tiled) texture is not 0,0
      // FIXME: we need to handle mNeedsYFlip, Bug #728625
      mOGLManager->BindAndDrawQuadWithTextureRect(program,
                                                  nsIntRect(0, 0, mTexImage->GetTileRect().width,
                                                                  mTexImage->GetTileRect().height),
                                                  mTexImage->GetTileRect().Size(),
                                                  mTexImage->GetWrapMode(),
                                                  mNeedsYFlip);
    } while (mTexImage->NextTile());
  }
}

//.........这里部分代码省略.........
    }
    childOffset.x = visibleRect.x;
    childOffset.y = visibleRect.y;
  } else {
    frameBuffer = aPreviousFrameBuffer;
    aContainer->mSupportsComponentAlphaChildren = (aContainer->GetContentFlags() & Layer::CONTENT_OPAQUE) ||
      (aContainer->GetParent() && aContainer->GetParent()->SupportsComponentAlphaChildren());
  }

  nsAutoTArray<Layer*, 12> children;
  aContainer->SortChildrenBy3DZOrder(children);

  /**
   * Render this container's contents.
   */
  for (uint32_t i = 0; i < children.Length(); i++) {
    LayerOGL* layerToRender = static_cast<LayerOGL*>(children.ElementAt(i)->ImplData());

    if (layerToRender->GetLayer()->GetEffectiveVisibleRegion().IsEmpty()) {
      continue;
    }

    nsIntRect scissorRect = layerToRender->GetLayer()->
        CalculateScissorRect(cachedScissor, &aManager->GetWorldTransform());
    if (scissorRect.IsEmpty()) {
      continue;
    }

    aContainer->gl()->fScissor(scissorRect.x, 
                               scissorRect.y, 
                               scissorRect.width, 
                               scissorRect.height);

    layerToRender->RenderLayer(frameBuffer, childOffset);
    aContainer->gl()->MakeCurrent();
  }


  if (needsFramebuffer) {
    // Unbind the current framebuffer and rebind the previous one.
#ifdef MOZ_DUMP_PAINTING
    if (gfxUtils::sDumpPainting) {
      nsRefPtr<gfxImageSurface> surf = 
        aContainer->gl()->GetTexImage(containerSurface, true, aManager->GetFBOLayerProgramType());

      WriteSnapshotToDumpFile(aContainer, surf);
    }
#endif
    
    // Restore the viewport
    aContainer->gl()->PopViewportRect();
    nsIntRect viewport = aContainer->gl()->ViewportRect();
    aManager->SetupPipeline(viewport.width, viewport.height,
                            LayerManagerOGL::ApplyWorldTransform);
    aContainer->gl()->PopScissorRect();
    aContainer->gl()->fBindFramebuffer(LOCAL_GL_FRAMEBUFFER, aPreviousFrameBuffer);

    if (!aManager->CompositingDisabled()) {
      aContainer->gl()->fDeleteFramebuffers(1, &frameBuffer);

      aContainer->gl()->fActiveTexture(LOCAL_GL_TEXTURE0);

      aContainer->gl()->fBindTexture(aManager->FBOTextureTarget(), containerSurface);

      MaskType maskType = MaskNone;
      if (aContainer->GetMaskLayer()) {
        if (!aContainer->GetTransform().CanDraw2D()) {
          maskType = Mask3d;
        } else {
          maskType = Mask2d;
        }
      }
      ShaderProgramOGL *rgb =
        aManager->GetFBOLayerProgram(maskType);

      rgb->Activate();
      rgb->SetLayerQuadRect(visibleRect);
      rgb->SetLayerTransform(transform);
      rgb->SetLayerOpacity(opacity);
      rgb->SetRenderOffset(aOffset);
      rgb->SetTextureUnit(0);
      rgb->LoadMask(aContainer->GetMaskLayer());

      if (rgb->GetTexCoordMultiplierUniformLocation() != -1) {
        // 2DRect case, get the multiplier right for a sampler2DRect
        rgb->SetTexCoordMultiplier(visibleRect.width, visibleRect.height);
      }

      // Drawing is always flipped, but when copying between surfaces we want to avoid
      // this. Pass true for the flip parameter to introduce a second flip
      // that cancels the other one out.
      aManager->BindAndDrawQuad(rgb, true);

      // Clean up resources.  This also unbinds the texture.
      aContainer->gl()->fDeleteTextures(1, &containerSurface);
    }
  } else {
    aContainer->gl()->PopScissorRect();
  }
}

void
CanvasLayerOGL::RenderLayer(int aPreviousDestination,
                            const nsIntPoint& aOffset)
{
  FirePreTransactionCallback();
  UpdateSurface();
  if (mOGLManager->CompositingDisabled()) {
    return;
  }
  FireDidTransactionCallback();

  mOGLManager->MakeCurrent();

  // XXX We're going to need a different program depending on if
  // mGLBufferIsPremultiplied is TRUE or not.  The RGBLayerProgram
  // assumes that it's true.

  gl()->fActiveTexture(LOCAL_GL_TEXTURE0);

  if (mTexture) {
    gl()->fBindTexture(mTextureTarget, mTexture);
  }

  ShaderProgramOGL *program = nullptr;

  nsIntRect drawRect = mBounds;
  if (mDelayedUpdates) {
    NS_ABORT_IF_FALSE(mCanvasSurface || mDrawTarget, "WebGL canvases should always be using full texture upload");
    
    drawRect.IntersectRect(drawRect, GetEffectiveVisibleRegion().GetBounds());

    gfx::SurfaceFormat format =
      gl()->UploadSurfaceToTexture(mCanvasSurface,
                                   nsIntRect(0, 0, drawRect.width, drawRect.height),
                                   mUploadTexture,
                                   true,
                                   drawRect.TopLeft());
    mLayerProgram = ShaderProgramFromSurfaceFormat(format);
    mTexture = mUploadTexture;
  }

  if (!program) {
    program = mOGLManager->GetProgram(mLayerProgram, GetMaskLayer());
  }

#if defined(GL_PROVIDER_GLX)
  if (mPixmap && !mDelayedUpdates) {
    sDefGLXLib.BindTexImage(mPixmap);
  }
#endif

  gl()->ApplyFilterToBoundTexture(mFilter);

  program->Activate();
  if (mLayerProgram == RGBARectLayerProgramType ||
      mLayerProgram == RGBXRectLayerProgramType) {
    // This is used by IOSurface that use 0,0...w,h coordinate rather then 0,0..1,1.
    program->SetTexCoordMultiplier(mBounds.width, mBounds.height);
  }
  program->SetLayerQuadRect(drawRect);
  program->SetLayerTransform(GetEffectiveTransform());
  program->SetTextureTransform(gfx3DMatrix());
  program->SetLayerOpacity(GetEffectiveOpacity());
  program->SetRenderOffset(aOffset);
  program->SetTextureUnit(0);
  program->LoadMask(GetMaskLayer());

  if (gl()->CanUploadNonPowerOfTwo()) {
    mOGLManager->BindAndDrawQuad(program, mNeedsYFlip ? true : false);
  } else {
    mOGLManager->BindAndDrawQuadWithTextureRect(program, drawRect, drawRect.Size());
  }

#if defined(GL_PROVIDER_GLX)
  if (mPixmap && !mDelayedUpdates) {
    sDefGLXLib.ReleaseTexImage(mPixmap);
  }
#endif
}

void
ShadowCanvasLayerOGL::RenderLayer(int aPreviousFrameBuffer,
                                  const nsIntPoint& aOffset)
{
  if (!mTexImage && !IsValidSharedTexDescriptor(mFrontBufferDescriptor)) {
    return;
  }

  if (mOGLManager->CompositingDisabled()) {
    return;
  }
  mOGLManager->MakeCurrent();

  gfx3DMatrix effectiveTransform = GetEffectiveTransform();
  gfxPattern::GraphicsFilter filter = mFilter;
#ifdef ANDROID
  // Bug 691354
  // Using the LINEAR filter we get unexplained artifacts.
  // Use NEAREST when no scaling is required.
  gfxMatrix matrix;
  bool is2D = GetEffectiveTransform().Is2D(&matrix);
  if (is2D && !matrix.HasNonTranslationOrFlip()) {
    filter = gfxPattern::FILTER_NEAREST;
  }
#endif

  ShaderProgramOGL *program;
  if (IsValidSharedTexDescriptor(mFrontBufferDescriptor)) {
    program = mOGLManager->GetBasicLayerProgram(CanUseOpaqueSurface(),
                                                true,
                                                GetMaskLayer() ? Mask2d : MaskNone);
  } else {
    program = mOGLManager->GetProgram(mTexImage->GetShaderProgramType(),
                                      GetMaskLayer());
  }

  program->Activate();
  program->SetLayerTransform(effectiveTransform);
  program->SetLayerOpacity(GetEffectiveOpacity());
  program->SetRenderOffset(aOffset);
  program->SetTextureUnit(0);
  program->LoadMask(GetMaskLayer());

  if (IsValidSharedTexDescriptor(mFrontBufferDescriptor)) {
    // Shared texture handle rendering path, single texture rendering
    SharedTextureDescriptor texDescriptor = mFrontBufferDescriptor.get_SharedTextureDescriptor();
    gl()->fActiveTexture(LOCAL_GL_TEXTURE0);
    gl()->fBindTexture(LOCAL_GL_TEXTURE_2D, mTexture);
    if (!gl()->AttachSharedHandle(texDescriptor.shareType(), texDescriptor.handle())) {
      NS_ERROR("Failed to attach shared texture handle");
      return;
    }
    gl()->ApplyFilterToBoundTexture(filter);
    program->SetLayerQuadRect(nsIntRect(nsIntPoint(0, 0), texDescriptor.size()));
    mOGLManager->BindAndDrawQuad(program, mNeedsYFlip);
    gl()->DetachSharedHandle(texDescriptor.shareType(), texDescriptor.handle());
    gl()->fBindTexture(LOCAL_GL_TEXTURE_2D, 0);
  } else {
    // Tiled texture image rendering path
    mTexImage->SetFilter(filter);
    mTexImage->BeginTileIteration();
    if (gl()->CanUploadNonPowerOfTwo()) {
      do {
        TextureImage::ScopedBindTextureAndApplyFilter texBind(mTexImage, LOCAL_GL_TEXTURE0);
        program->SetLayerQuadRect(mTexImage->GetTileRect());
        mOGLManager->BindAndDrawQuad(program, mNeedsYFlip); // FIXME flip order of tiles?
      } while (mTexImage->NextTile());
    } else {
      do {
        TextureImage::ScopedBindTextureAndApplyFilter texBind(mTexImage, LOCAL_GL_TEXTURE0);
        program->SetLayerQuadRect(mTexImage->GetTileRect());
        // We can't use BindAndDrawQuad because that always uploads the whole texture from 0.0f -> 1.0f
        // in x and y. We use BindAndDrawQuadWithTextureRect to actually draw a subrect of the texture
        // We need to reset the origin to 0,0 from the tile rect because the tile originates at 0,0 in the
        // actual texture, even though its origin in the composed (tiled) texture is not 0,0
        // FIXME: we need to handle mNeedsYFlip, Bug #728625
        mOGLManager->BindAndDrawQuadWithTextureRect(program,
                                                    nsIntRect(0, 0, mTexImage->GetTileRect().width,
                                                                    mTexImage->GetTileRect().height),
                                                    mTexImage->GetTileRect().Size(),
                                                    mTexImage->GetWrapMode(),
                                                    mNeedsYFlip);
      } while (mTexImage->NextTile());
    }
  }
}

void
ShadowImageLayerOGL::RenderLayer(int aPreviousFrameBuffer,
                                 const nsIntPoint& aOffset)
{
  if (mOGLManager->CompositingDisabled()) {
    return;
  }
  mOGLManager->MakeCurrent();
  if (mImageContainerID) {
    ImageContainerParent::SetCompositorIDForImage(mImageContainerID,
                                                  mOGLManager->GetCompositorID());
    uint32_t imgVersion = ImageContainerParent::GetSharedImageVersion(mImageContainerID);
    SharedImage* img = ImageContainerParent::GetSharedImage(mImageContainerID);
    if (imgVersion != mImageVersion) {
      if (img && (img->type() == SharedImage::TYUVImage)) {
        UploadSharedYUVToTexture(img->get_YUVImage());
  
        mImageVersion = imgVersion;
      } else if (img && (img->type() == SharedImage::TYCbCrImage)) {
        ShmemYCbCrImage shmemImage(img->get_YCbCrImage().data(),
                                   img->get_YCbCrImage().offset());
        UploadSharedYCbCrToTexture(shmemImage, img->get_YCbCrImage().picture());

        mImageVersion = imgVersion;
      } else if (img && (img->type() == SharedImage::TRGBImage)) {
        UploadSharedRGBToTexture(&img->get_RGBImage().data(),
                                 img->get_RGBImage().picture(),
                                 img->get_RGBImage().rgbFormat());
        mImageVersion = imgVersion;
      }
    }
#ifdef MOZ_WIDGET_GONK
    if (img
        && (img->type() == SharedImage::TSurfaceDescriptor)
        && (img->get_SurfaceDescriptor().type() == SurfaceDescriptor::TSurfaceDescriptorGralloc)) {
      const SurfaceDescriptorGralloc& desc = img->get_SurfaceDescriptor().get_SurfaceDescriptorGralloc();
      sp<GraphicBuffer> graphicBuffer = GrallocBufferActor::GetFrom(desc);
      mSize = gfxIntSize(graphicBuffer->getWidth(), graphicBuffer->getHeight());
      if (!mExternalBufferTexture.IsAllocated()) {
        mExternalBufferTexture.Allocate(gl());
      }
      gl()->MakeCurrent();
      gl()->fActiveTexture(LOCAL_GL_TEXTURE0);
      gl()->BindExternalBuffer(mExternalBufferTexture.GetTextureID(), graphicBuffer->getNativeBuffer());
      mImageVersion = imgVersion;
    }
#endif
  }


  if (mTexImage) {
    NS_ASSERTION(mTexImage->GetContentType() != gfxASurface::CONTENT_ALPHA,
                 "Image layer has alpha image");

    ShaderProgramOGL *colorProgram =
      mOGLManager->GetProgram(mTexImage->GetShaderProgramType(), GetMaskLayer());

    colorProgram->Activate();
    colorProgram->SetTextureUnit(0);
    colorProgram->SetLayerTransform(GetEffectiveTransform());
    colorProgram->SetLayerOpacity(GetEffectiveOpacity());
    colorProgram->SetRenderOffset(aOffset);
    colorProgram->LoadMask(GetMaskLayer());

    mTexImage->SetFilter(mFilter);
    mTexImage->BeginTileIteration();

    if (gl()->CanUploadNonPowerOfTwo()) {
      do {
        nsIntRect rect = mTexImage->GetTileRect();
        if (!rect.IsEmpty()) {
          TextureImage::ScopedBindTextureAndApplyFilter texBind(mTexImage, LOCAL_GL_TEXTURE0);
          colorProgram->SetLayerQuadRect(rect);
          mOGLManager->BindAndDrawQuad(colorProgram);
        }
      } while (mTexImage->NextTile());
    } else {
      do {
        nsIntRect rect = mTexImage->GetTileRect();
        if (!rect.IsEmpty()) {
          TextureImage::ScopedBindTextureAndApplyFilter texBind(mTexImage, LOCAL_GL_TEXTURE0);
          colorProgram->SetLayerQuadRect(rect);
          // We can't use BindAndDrawQuad because that always uploads the whole texture from 0.0f -> 1.0f
          // in x and y. We use BindAndDrawQuadWithTextureRect to actually draw a subrect of the texture
          mOGLManager->BindAndDrawQuadWithTextureRect(colorProgram,
                                                      nsIntRect(0, 0, mTexImage->GetTileRect().width,
                                                                mTexImage->GetTileRect().height),
                                                      mTexImage->GetTileRect().Size());
        }
      } while (mTexImage->NextTile());
    }
#ifdef MOZ_WIDGET_GONK
  } else if (mExternalBufferTexture.IsAllocated()) {
    gl()->MakeCurrent();
    gl()->fActiveTexture(LOCAL_GL_TEXTURE0);
    gl()->fBindTexture(LOCAL_GL_TEXTURE_EXTERNAL, mExternalBufferTexture.GetTextureID());

    ShaderProgramOGL *program = mOGLManager->GetProgram(RGBAExternalLayerProgramType, GetMaskLayer());

    gl()->ApplyFilterToBoundTexture(LOCAL_GL_TEXTURE_EXTERNAL, mFilter);
//.........这里部分代码省略.........

//.........这里部分代码省略.........
      // If this texture was allocated by another layer manager, clear
      // it out and re-allocate below.
      data = nullptr;
      cairoImage->SetBackendData(LAYERS_OPENGL, nullptr);
    }

    if (!data) {
      AllocateTexturesCairo(cairoImage);
      data = static_cast<CairoOGLBackendData*>(cairoImage->GetBackendData(LAYERS_OPENGL));
    }

    if (!data || data->mTexture.GetGLContext() != gl()) {
      // XXX - Can this ever happen? If so I need to fix this!
      return;
    }

    gl()->MakeCurrent();

    gl()->fActiveTexture(LOCAL_GL_TEXTURE0);
    gl()->fBindTexture(LOCAL_GL_TEXTURE_2D, data->mTexture.GetTextureID());

    ShaderProgramOGL *program = 
      mOGLManager->GetProgram(data->mLayerProgram, GetMaskLayer());

    gl()->ApplyFilterToBoundTexture(mFilter);

    program->Activate();
    program->SetLayerQuadRect(nsIntRect(0, 0, 
                                        cairoImage->GetSize().width, 
                                        cairoImage->GetSize().height));
    program->SetLayerTransform(GetEffectiveTransform());
    program->SetLayerOpacity(GetEffectiveOpacity());
    program->SetRenderOffset(aOffset);
    program->SetTextureUnit(0);
    program->LoadMask(GetMaskLayer());

    mOGLManager->BindAndDrawQuad(program);
#ifdef XP_MACOSX
  } else if (image->GetFormat() == MAC_IO_SURFACE) {
     MacIOSurfaceImage *ioImage =
       static_cast<MacIOSurfaceImage*>(image);

     if (!mOGLManager->GetThebesLayerCallback()) {
       // If its an empty transaction we still need to update
       // the plugin IO Surface and make sure we grab the
       // new image
       ioImage->Update(GetContainer());
       image = nullptr;
       autoLock.Refresh();
       image = autoLock.GetImage();
       gl()->MakeCurrent();
       ioImage = static_cast<MacIOSurfaceImage*>(image);
     }

     if (!ioImage) {
       return;
     }

     gl()->fActiveTexture(LOCAL_GL_TEXTURE0);

     if (!ioImage->GetBackendData(LAYERS_OPENGL)) {
       AllocateTextureIOSurface(ioImage, gl());
     }

     MacIOSurfaceImageOGLBackendData *data =
      static_cast<MacIOSurfaceImageOGLBackendData*>(ioImage->GetBackendData(LAYERS_OPENGL));

//.........这里部分代码省略.........
        break;
      }
      case SharedSurfaceType::EGLImageShare: {
        SharedSurface_EGLImage* eglImageSurf =
            SharedSurface_EGLImage::Cast(sharedSurf);

        mCurTexture = eglImageSurf->AcquireConsumerTexture(gl());
        if (!mCurTexture) {
          toUpload = eglImageSurf->GetPixels();
          MOZ_ASSERT(toUpload);
        } else {
          mShaderType = sharedSurf->HasAlpha() ? RGBALayerProgramType
                                               : RGBXLayerProgramType;
        }
        break;
      }
      case SharedSurfaceType::Basic: {
        toUpload = SharedSurface_Basic::Cast(sharedSurf)->GetData();
        MOZ_ASSERT(toUpload);
        break;
      }
      default:
        MOZ_NOT_REACHED("Invalid SharedSurface type.");
        return;
    }

    if (toUpload) {
      // mBounds seems to end up as (0,0,0,0) a lot, so don't use it?
      nsIntSize size(toUpload->GetSize());
      nsIntRect rect(nsIntPoint(0,0), size);
      nsIntRegion bounds(rect);
      mShaderType = gl()->UploadSurfaceToTexture(toUpload,
                                                 bounds,
                                                 mUploadTexture,
                                                 true);
      mCurTexture = mUploadTexture;
    }

    MOZ_ASSERT(mCurTexture);
    gl()->fBindTexture(LOCAL_GL_TEXTURE_2D, mCurTexture);
    gl()->fTexParameteri(LOCAL_GL_TEXTURE_2D,
                         LOCAL_GL_TEXTURE_WRAP_S,
                         LOCAL_GL_CLAMP_TO_EDGE);
    gl()->fTexParameteri(LOCAL_GL_TEXTURE_2D,
                         LOCAL_GL_TEXTURE_WRAP_T,
                         LOCAL_GL_CLAMP_TO_EDGE);
  } else if (mTexImage) {
    mShaderType = mTexImage->GetShaderProgramType();
  } else {
    MOZ_NOT_REACHED("What can we do?");
    return;
  }

  ShaderProgramOGL* program = mOGLManager->GetProgram(mShaderType, GetMaskLayer());

  program->Activate();
  program->SetLayerTransform(effectiveTransform);
  program->SetLayerOpacity(GetEffectiveOpacity());
  program->SetRenderOffset(aOffset);
  program->SetTextureUnit(0);
  program->LoadMask(GetMaskLayer());

  if (surfStream) {
    MOZ_ASSERT(sharedSurf);

    gl()->ApplyFilterToBoundTexture(filter);
    program->SetLayerQuadRect(nsIntRect(nsIntPoint(0, 0), sharedSurf->Size()));

    mOGLManager->BindAndDrawQuad(program, mNeedsYFlip);

    gl()->fBindTexture(LOCAL_GL_TEXTURE_2D, 0);
  } else {
    // Tiled texture image rendering path
    mTexImage->SetFilter(filter);
    mTexImage->BeginTileIteration();
    if (gl()->CanUploadNonPowerOfTwo()) {
      do {
        TextureImage::ScopedBindTextureAndApplyFilter texBind(mTexImage, LOCAL_GL_TEXTURE0);
        program->SetLayerQuadRect(mTexImage->GetTileRect());
        mOGLManager->BindAndDrawQuad(program, mNeedsYFlip); // FIXME flip order of tiles?
      } while (mTexImage->NextTile());
    } else {
      do {
        TextureImage::ScopedBindTextureAndApplyFilter texBind(mTexImage, LOCAL_GL_TEXTURE0);
        program->SetLayerQuadRect(mTexImage->GetTileRect());
        // We can't use BindAndDrawQuad because that always uploads the whole texture from 0.0f -> 1.0f
        // in x and y. We use BindAndDrawQuadWithTextureRect to actually draw a subrect of the texture
        // We need to reset the origin to 0,0 from the tile rect because the tile originates at 0,0 in the
        // actual texture, even though its origin in the composed (tiled) texture is not 0,0
        // FIXME: we need to handle mNeedsYFlip, Bug #728625
        mOGLManager->BindAndDrawQuadWithTextureRect(program,
                                                    nsIntRect(0, 0, mTexImage->GetTileRect().width,
                                                                    mTexImage->GetTileRect().height),
                                                    mTexImage->GetTileRect().Size(),
                                                    mTexImage->GetWrapMode(),
                                                    mNeedsYFlip);
      } while (mTexImage->NextTile());
    }
  }
}

void
CanvasLayerOGL::RenderLayer(int aPreviousDestination,
                            const nsIntPoint& aOffset)
{
  UpdateSurface();
  FireDidTransactionCallback();

  mOGLManager->MakeCurrent();

  // XXX We're going to need a different program depending on if
  // mGLBufferIsPremultiplied is TRUE or not.  The RGBLayerProgram
  // assumes that it's true.

  gl()->fActiveTexture(LOCAL_GL_TEXTURE0);

  if (mTexture) {
    gl()->fBindTexture(LOCAL_GL_TEXTURE_2D, mTexture);
  }

  ShaderProgramOGL *program = nsnull;

  bool useGLContext = mCanvasGLContext &&
    mCanvasGLContext->GetContextType() == gl()->GetContextType();

  nsIntRect drawRect = mBounds;

  if (useGLContext) {
    gl()->BindTex2DOffscreen(mCanvasGLContext);
    program = mOGLManager->GetBasicLayerProgram(CanUseOpaqueSurface(),
                                                true,
                                                GetMaskLayer() ? Mask2d : MaskNone);
  } else if (mDelayedUpdates) {
    NS_ABORT_IF_FALSE(mCanvasSurface || mDrawTarget, "WebGL canvases should always be using full texture upload");
    
    drawRect.IntersectRect(drawRect, GetEffectiveVisibleRegion().GetBounds());

    nsRefPtr<gfxASurface> surf = mCanvasSurface;
    if (mDrawTarget) {
      surf = gfxPlatform::GetPlatform()->GetThebesSurfaceForDrawTarget(mDrawTarget);
    }

    mLayerProgram =
      gl()->UploadSurfaceToTexture(surf,
                                   nsIntRect(0, 0, drawRect.width, drawRect.height),
                                   mTexture,
                                   true,
                                   drawRect.TopLeft());
  }

  if (!program) {
    program = mOGLManager->GetProgram(mLayerProgram, GetMaskLayer());
  }

#if defined(MOZ_WIDGET_GTK2) && !defined(MOZ_PLATFORM_MAEMO)
  if (mPixmap && !mDelayedUpdates) {
    sGLXLibrary.BindTexImage(mPixmap);
  }
#endif

  gl()->ApplyFilterToBoundTexture(mFilter);

  program->Activate();
  program->SetLayerQuadRect(drawRect);
  program->SetLayerTransform(GetEffectiveTransform());
  program->SetLayerOpacity(GetEffectiveOpacity());
  program->SetRenderOffset(aOffset);
  program->SetTextureUnit(0);
  program->LoadMask(GetMaskLayer());

  if (gl()->CanUploadNonPowerOfTwo()) {
    mOGLManager->BindAndDrawQuad(program, mNeedsYFlip ? true : false);
  } else {
    mOGLManager->BindAndDrawQuadWithTextureRect(program, drawRect, drawRect.Size());
  }

#if defined(MOZ_WIDGET_GTK2) && !defined(MOZ_PLATFORM_MAEMO)
  if (mPixmap && !mDelayedUpdates) {
    sGLXLibrary.ReleaseTexImage(mPixmap);
  }
#endif

  if (useGLContext) {
    gl()->UnbindTex2DOffscreen(mCanvasGLContext);
  }
}

void
ShadowImageLayerOGL::RenderLayer(int aPreviousFrameBuffer,
                                 const nsIntPoint& aOffset)
{
  mOGLManager->MakeCurrent();
  if (mImageContainerID) {
    ImageContainerParent::SetCompositorIDForImage(mImageContainerID,
                                                  mOGLManager->GetCompositorID());
    PRUint32 imgVersion = ImageContainerParent::GetSharedImageVersion(mImageContainerID);
    if (imgVersion != mImageVersion) {
      SharedImage* img = ImageContainerParent::GetSharedImage(mImageContainerID);
      if (img && (img->type() == SharedImage::TYUVImage)) {
        UploadSharedYUVToTexture(img->get_YUVImage());
  
        mImageVersion = imgVersion;
      }
    }
  }


  if (mTexImage) {
    NS_ASSERTION(mTexImage->GetContentType() != gfxASurface::CONTENT_ALPHA,
                 "Image layer has alpha image");

    ShaderProgramOGL *colorProgram =
      mOGLManager->GetProgram(mTexImage->GetShaderProgramType(), GetMaskLayer());

    colorProgram->Activate();
    colorProgram->SetTextureUnit(0);
    colorProgram->SetLayerTransform(GetEffectiveTransform());
    colorProgram->SetLayerOpacity(GetEffectiveOpacity());
    colorProgram->SetRenderOffset(aOffset);
    colorProgram->LoadMask(GetMaskLayer());

    mTexImage->SetFilter(mFilter);
    mTexImage->BeginTileIteration();

    if (gl()->CanUploadNonPowerOfTwo()) {
      do {
        TextureImage::ScopedBindTextureAndApplyFilter texBind(mTexImage, LOCAL_GL_TEXTURE0);
        colorProgram->SetLayerQuadRect(mTexImage->GetTileRect());
        mOGLManager->BindAndDrawQuad(colorProgram);
      } while (mTexImage->NextTile());
    } else {
      do {
        TextureImage::ScopedBindTextureAndApplyFilter texBind(mTexImage, LOCAL_GL_TEXTURE0);
        colorProgram->SetLayerQuadRect(mTexImage->GetTileRect());
        // We can't use BindAndDrawQuad because that always uploads the whole texture from 0.0f -> 1.0f
        // in x and y. We use BindAndDrawQuadWithTextureRect to actually draw a subrect of the texture
        mOGLManager->BindAndDrawQuadWithTextureRect(colorProgram,
                                                    nsIntRect(0, 0, mTexImage->GetTileRect().width,
                                                                    mTexImage->GetTileRect().height),
                                                    mTexImage->GetTileRect().Size());
      } while (mTexImage->NextTile());
    }

  } else {
    gl()->fActiveTexture(LOCAL_GL_TEXTURE0);
    gl()->fBindTexture(LOCAL_GL_TEXTURE_2D, mYUVTexture[0].GetTextureID());
    gl()->ApplyFilterToBoundTexture(mFilter);
    gl()->fActiveTexture(LOCAL_GL_TEXTURE1);
    gl()->fBindTexture(LOCAL_GL_TEXTURE_2D, mYUVTexture[1].GetTextureID());
    gl()->ApplyFilterToBoundTexture(mFilter);
    gl()->fActiveTexture(LOCAL_GL_TEXTURE2);
    gl()->fBindTexture(LOCAL_GL_TEXTURE_2D, mYUVTexture[2].GetTextureID());
    gl()->ApplyFilterToBoundTexture(mFilter);

    ShaderProgramOGL *yuvProgram = mOGLManager->GetProgram(YCbCrLayerProgramType, GetMaskLayer());

    yuvProgram->Activate();
    yuvProgram->SetLayerQuadRect(nsIntRect(0, 0,
                                           mPictureRect.width,
                                           mPictureRect.height));
    yuvProgram->SetYCbCrTextureUnits(0, 1, 2);
    yuvProgram->SetLayerTransform(GetEffectiveTransform());
    yuvProgram->SetLayerOpacity(GetEffectiveOpacity());
    yuvProgram->SetRenderOffset(aOffset);
    yuvProgram->LoadMask(GetMaskLayer());

    mOGLManager->BindAndDrawQuadWithTextureRect(yuvProgram,
                                                mPictureRect,
                                                nsIntSize(mSize.width, mSize.height));
 }
}

//.........这里部分代码省略.........
      // If this texture was allocated by another layer manager, clear
      // it out and re-allocate below.
      data = nullptr;
      cairoImage->SetBackendData(LAYERS_OPENGL, nullptr);
    }

    if (!data) {
      AllocateTexturesCairo(cairoImage);
      data = static_cast<CairoOGLBackendData*>(cairoImage->GetBackendData(LAYERS_OPENGL));
    }

    if (!data || data->mTexture.GetGLContext() != gl()) {
      // XXX - Can this ever happen? If so I need to fix this!
      return;
    }

    gl()->MakeCurrent();

    gl()->fActiveTexture(LOCAL_GL_TEXTURE0);
    gl()->fBindTexture(LOCAL_GL_TEXTURE_2D, data->mTexture.GetTextureID());

    ShaderProgramOGL *program = 
      mOGLManager->GetProgram(data->mLayerProgram, GetMaskLayer());

    gl()->ApplyFilterToBoundTexture(mFilter);

    program->Activate();
    program->SetLayerQuadRect(nsIntRect(0, 0, 
                                        cairoImage->GetSize().width, 
                                        cairoImage->GetSize().height));
    program->SetLayerTransform(GetEffectiveTransform());
    program->SetLayerOpacity(GetEffectiveOpacity());
    program->SetRenderOffset(aOffset);
    program->SetTextureUnit(0);
    program->LoadMask(GetMaskLayer());

    mOGLManager->BindAndDrawQuad(program);
  } else if (image->GetFormat() == SHARED_TEXTURE) {
    SharedTextureImage* texImage =
      static_cast<SharedTextureImage*>(image);
    const SharedTextureImage::Data* data = texImage->GetData();
    GLContext::SharedHandleDetails handleDetails;
    if (!gl()->GetSharedHandleDetails(data->mShareType, data->mHandle, handleDetails)) {
      NS_ERROR("Failed to get shared handle details");
      return;
    }

    ShaderProgramOGL* program = mOGLManager->GetProgram(handleDetails.mProgramType, GetMaskLayer());

    program->Activate();
    if (handleDetails.mProgramType == gl::RGBARectLayerProgramType) {
      // 2DRect case, get the multiplier right for a sampler2DRect
      program->SetTexCoordMultiplier(data->mSize.width, data->mSize.height);
    }
    program->SetLayerTransform(GetEffectiveTransform());
    program->SetLayerOpacity(GetEffectiveOpacity());
    program->SetRenderOffset(aOffset);
    program->SetTextureUnit(0);
    program->SetTextureTransform(handleDetails.mTextureTransform);
    program->LoadMask(GetMaskLayer());

    if (!texImage->GetBackendData(LAYERS_OPENGL)) {
      AllocateTextureSharedTexture(texImage, gl(), handleDetails.mTarget);
    }

    ImageOGLBackendData *backendData =

//.........这里部分代码省略.........

    gl()->MakeCurrent();
    unsigned int iwidth  = cairoImage->mSize.width;
    unsigned int iheight = cairoImage->mSize.height;

    gl()->fActiveTexture(LOCAL_GL_TEXTURE0);
    gl()->fBindTexture(LOCAL_GL_TEXTURE_2D, data->mTexture.GetTextureID());

#if defined(MOZ_WIDGET_GTK2) && !defined(MOZ_PLATFORM_MAEMO)
    GLXPixmap pixmap;

    if (cairoImage->mSurface) {
        pixmap = sGLXLibrary.CreatePixmap(cairoImage->mSurface);
        NS_ASSERTION(pixmap, "Failed to create pixmap!");
        if (pixmap) {
            sGLXLibrary.BindTexImage(pixmap);
        }
    }
#endif

    ShaderProgramOGL *program = 
      mOGLManager->GetProgram(data->mLayerProgram, GetMaskLayer());

    gl()->ApplyFilterToBoundTexture(mFilter);

    program->Activate();
    // The following uniform controls the scaling of the vertex coords.
    // Instead of setting the scale here and using coords in the range [0,1], we
    // set an identity transform and use pixel coordinates below
    program->SetLayerQuadRect(nsIntRect(0, 0, 1, 1));
    program->SetLayerTransform(GetEffectiveTransform());
    program->SetLayerOpacity(GetEffectiveOpacity());
    program->SetRenderOffset(aOffset);
    program->SetTextureUnit(0);
    program->LoadMask(GetMaskLayer());

    nsIntRect rect = GetVisibleRegion().GetBounds();

    GLContext::RectTriangles triangleBuffer;

    float tex_offset_u = float(rect.x % iwidth) / iwidth;
    float tex_offset_v = float(rect.y % iheight) / iheight;
    triangleBuffer.addRect(rect.x, rect.y,
                           rect.x + rect.width, rect.y + rect.height,
                           tex_offset_u, tex_offset_v,
                           tex_offset_u + float(rect.width) / float(iwidth),
                           tex_offset_v + float(rect.height) / float(iheight));

    GLuint vertAttribIndex =
        program->AttribLocation(ShaderProgramOGL::VertexCoordAttrib);
    GLuint texCoordAttribIndex =
        program->AttribLocation(ShaderProgramOGL::TexCoordAttrib);
    NS_ASSERTION(texCoordAttribIndex != GLuint(-1), "no texture coords?");

    gl()->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, 0);
    gl()->fVertexAttribPointer(vertAttribIndex, 2,
                               LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0,
                               triangleBuffer.vertexPointer());

    gl()->fVertexAttribPointer(texCoordAttribIndex, 2,
                               LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0,
                               triangleBuffer.texCoordPointer());
    {
        gl()->fEnableVertexAttribArray(texCoordAttribIndex);
        {
            gl()->fEnableVertexAttribArray(vertAttribIndex);