C++ Compositor::ClipRectInLayersCoordinates方法代码示例

// ContainerRender is shared between RefLayer and ContainerLayer
template<class ContainerT> void
ContainerRender(ContainerT* aContainer,
                LayerManagerComposite* aManager,
                const nsIntRect& aClipRect)
{
  /**
   * Setup our temporary surface for rendering the contents of this container.
   */
  RefPtr<CompositingRenderTarget> surface;

  Compositor* compositor = aManager->GetCompositor();

  RefPtr<CompositingRenderTarget> previousTarget = compositor->GetCurrentRenderTarget();

  nsIntRect visibleRect = aContainer->GetEffectiveVisibleRegion().GetBounds();

  float opacity = aContainer->GetEffectiveOpacity();

  bool needsSurface = aContainer->UseIntermediateSurface();
  bool surfaceCopyNeeded;
  aContainer->DefaultComputeSupportsComponentAlphaChildren(&surfaceCopyNeeded);
  if (needsSurface) {
    SurfaceInitMode mode = INIT_MODE_CLEAR;
    gfx::IntRect surfaceRect = gfx::IntRect(visibleRect.x, visibleRect.y,
                                            visibleRect.width, visibleRect.height);
    // we're about to create a framebuffer backed by textures to use as an intermediate
    // surface. What to do if its size (as given by framebufferRect) would exceed the
    // maximum texture size supported by the GL? The present code chooses the compromise
    // of just clamping the framebuffer's size to the max supported size.
    // This gives us a lower resolution rendering of the intermediate surface (children layers).
    // See bug 827170 for a discussion.
    int32_t maxTextureSize = compositor->GetMaxTextureSize();
    surfaceRect.width = std::min(maxTextureSize, surfaceRect.width);
    surfaceRect.height = std::min(maxTextureSize, surfaceRect.height);
    if (aContainer->GetEffectiveVisibleRegion().GetNumRects() == 1 &&
        (aContainer->GetContentFlags() & Layer::CONTENT_OPAQUE))
    {
      mode = INIT_MODE_NONE;
    }

    if (surfaceCopyNeeded) {
      gfx::IntPoint sourcePoint = gfx::IntPoint(visibleRect.x, visibleRect.y);

      gfx::Matrix4x4 transform = aContainer->GetEffectiveTransform();
      DebugOnly<gfx::Matrix> transform2d;
      MOZ_ASSERT(transform.Is2D(&transform2d) && !gfx::ThebesMatrix(transform2d).HasNonIntegerTranslation());
      sourcePoint += gfx::IntPoint(transform._41, transform._42);

      sourcePoint -= compositor->GetCurrentRenderTarget()->GetOrigin();

      surface = compositor->CreateRenderTargetFromSource(surfaceRect, previousTarget, sourcePoint);
    } else {
      surface = compositor->CreateRenderTarget(surfaceRect, mode);
    }

    if (!surface) {
      return;
    }

    compositor->SetRenderTarget(surface);
  } else {
    surface = previousTarget;
  }

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

  // If this is a scrollable container layer, and it's overscrolled, the layer's
  // contents are transformed in a way that would leave blank regions in the
  // composited area. If the layer has a background color, fill these areas
  // with the background color by drawing a rectangle of the background color
  // over the entire composited area before drawing the container contents.
  if (AsyncPanZoomController* apzc = aContainer->GetAsyncPanZoomController()) {
    // Make sure not to do this on a "scrollinfo" layer (one with an empty visible
    // region) because it's just a placeholder for APZ purposes.
    if (apzc->IsOverscrolled() && !aContainer->GetVisibleRegion().IsEmpty()) {
      gfxRGBA color = aContainer->GetBackgroundColor();
      // If the background is completely transparent, there's no point in
      // drawing anything for it. Hopefully the layers behind, if any, will
      // provide suitable content for the overscroll effect.
      if (color.a != 0.0) {
        EffectChain effectChain(aContainer);
        effectChain.mPrimaryEffect = new EffectSolidColor(ToColor(color));
        gfx::Rect clipRect(aClipRect.x, aClipRect.y, aClipRect.width, aClipRect.height);
        Compositor* compositor = aManager->GetCompositor();
        compositor->DrawQuad(compositor->ClipRectInLayersCoordinates(clipRect),
            clipRect, effectChain, opacity, Matrix4x4());
      }
    }
  }

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

    if (layerToRender->GetLayer()->GetEffectiveVisibleRegion().IsEmpty() &&
        !layerToRender->GetLayer()->AsContainerLayer()) {
//.........这里部分代码省略.........