C++ LayerList::append方法代码示例

void CCLayerTreeHost::updateLayers(LayerChromium* rootLayer, CCTextureUpdater& updater)
{
    TRACE_EVENT("CCLayerTreeHost::updateLayers", this, 0);

    if (!rootLayer->renderSurface())
        rootLayer->createRenderSurface();
    rootLayer->renderSurface()->setContentRect(IntRect(IntPoint(0, 0), deviceViewportSize()));

    IntRect rootClipRect(IntPoint(), deviceViewportSize());
    rootLayer->setClipRect(rootClipRect);

    LayerList updateList;
    updateList.append(rootLayer);

    RenderSurfaceChromium* rootRenderSurface = rootLayer->renderSurface();
    rootRenderSurface->clearLayerList();

    {
        TRACE_EVENT("CCLayerTreeHost::updateLayers::calcDrawEtc", this, 0);
        WebTransformationMatrix identityMatrix;
        WebTransformationMatrix deviceScaleTransform;
        deviceScaleTransform.scale(m_deviceScaleFactor);
        CCLayerTreeHostCommon::calculateDrawTransforms(rootLayer, rootLayer, deviceScaleTransform, identityMatrix, updateList, rootRenderSurface->layerList(), layerRendererCapabilities().maxTextureSize);

        FloatRect rootScissorRect(FloatPoint(0, 0), viewportSize());
        CCLayerTreeHostCommon::calculateVisibleAndScissorRects(updateList, rootScissorRect);
    }

    // Reset partial texture update requests.
    m_partialTextureUpdateRequests = 0;

    reserveTextures(updateList);

    paintLayerContents(updateList, PaintVisible, updater);
    if (!m_triggerIdlePaints)
        return;

    size_t preferredLimitBytes = m_contentsTextureManager->preferredMemoryLimitBytes();
    size_t maxLimitBytes = m_contentsTextureManager->maxMemoryLimitBytes();
    m_contentsTextureManager->reduceMemoryToLimit(preferredLimitBytes);
    if (m_contentsTextureManager->currentMemoryUseBytes() >= preferredLimitBytes)
        return;

    // Idle painting should fail when we hit the preferred memory limit,
    // otherwise it will always push us towards the maximum limit.
    m_contentsTextureManager->setMaxMemoryLimitBytes(preferredLimitBytes);
    // The second (idle) paint will be a no-op in layers where painting already occured above.
    paintLayerContents(updateList, PaintIdle, updater);
    m_contentsTextureManager->setMaxMemoryLimitBytes(maxLimitBytes);

    for (size_t i = 0; i < updateList.size(); ++i)
        updateList[i]->clearRenderSurface();
}

// Recursively walks the layer tree starting at the given node and computes all the
// necessary transformations, scissor rectangles, render surfaces, etc.
void LayerRendererChromium::updatePropertiesAndRenderSurfaces(CCLayerImpl* layer, const TransformationMatrix& parentMatrix, LayerList& renderSurfaceLayerList, LayerList& layerList)
{
    // Compute the new matrix transformation that will be applied to this layer and
    // all its children. It's important to remember that the layer's position
    // is the position of the layer's anchor point. Also, the coordinate system used
    // assumes that the origin is at the lower left even though the coordinates the browser
    // gives us for the layers are for the upper left corner. The Y flip happens via
    // the orthographic projection applied at render time.
    // The transformation chain for the layer is (using the Matrix x Vector order):
    // M = M[p] * Tr[l] * M[l] * Tr[c]
    // Where M[p] is the parent matrix passed down to the function
    //       Tr[l] is the translation matrix locating the layer's anchor point
    //       Tr[c] is the translation offset between the anchor point and the center of the layer
    //       M[l] is the layer's matrix (applied at the anchor point)
    // This transform creates a coordinate system whose origin is the center of the layer.
    // Note that the final matrix used by the shader for the layer is P * M * S . This final product
    // is computed in drawTexturedQuad().
    // Where: P is the projection matrix
    //        M is the layer's matrix computed above
    //        S is the scale adjustment (to scale up to the layer size)
    IntSize bounds = layer->bounds();
    FloatPoint anchorPoint = layer->anchorPoint();
    FloatPoint position = layer->position();

    // Offset between anchor point and the center of the quad.
    float centerOffsetX = (0.5 - anchorPoint.x()) * bounds.width();
    float centerOffsetY = (0.5 - anchorPoint.y()) * bounds.height();

    TransformationMatrix layerLocalTransform;
    // LT = Tr[l]
    layerLocalTransform.translate3d(position.x(), position.y(), layer->anchorPointZ());
    // LT = Tr[l] * M[l]
    layerLocalTransform.multiply(layer->transform());
    // LT = Tr[l] * M[l] * Tr[c]
    layerLocalTransform.translate3d(centerOffsetX, centerOffsetY, -layer->anchorPointZ());

    TransformationMatrix combinedTransform = parentMatrix;
    combinedTransform = combinedTransform.multiply(layerLocalTransform);

    FloatRect layerRect(-0.5 * layer->bounds().width(), -0.5 * layer->bounds().height(), layer->bounds().width(), layer->bounds().height());
    IntRect transformedLayerRect;

    // The layer and its descendants render on a new RenderSurface if any of
    // these conditions hold:
    // 1. The layer clips its descendants and its transform is not a simple translation.
    // 2. If the layer has opacity != 1 and does not have a preserves-3d transform style.
    // 3. The layer uses a mask
    // 4. The layer has a replica (used for reflections)
    // 5. The layer doesn't preserve-3d but is the child of a layer which does.
    // If a layer preserves-3d then we don't create a RenderSurface for it to avoid flattening
    // out its children. The opacity value of the children layers is multiplied by the opacity
    // of their parent.
    bool useSurfaceForClipping = layer->masksToBounds() && !isScaleOrTranslation(combinedTransform);
    bool useSurfaceForOpacity = layer->opacity() != 1 && !layer->preserves3D();
    bool useSurfaceForMasking = layer->maskLayer();
    bool useSurfaceForReflection = layer->replicaLayer();
    bool useSurfaceForFlatDescendants = layer->parent() && layer->parent()->preserves3D() && !layer->preserves3D() && layer->descendantsDrawsContent();
    if (useSurfaceForMasking || useSurfaceForReflection || useSurfaceForFlatDescendants || ((useSurfaceForClipping || useSurfaceForOpacity) && layer->descendantsDrawsContent())) {
        RenderSurfaceChromium* renderSurface = layer->renderSurface();
        if (!renderSurface)
            renderSurface = layer->createRenderSurface();

        // The origin of the new surface is the upper left corner of the layer.
        TransformationMatrix drawTransform;
        drawTransform.translate3d(0.5 * bounds.width(), 0.5 * bounds.height(), 0);
        layer->setDrawTransform(drawTransform);

        transformedLayerRect = IntRect(0, 0, bounds.width(), bounds.height());

        // Layer's opacity will be applied when drawing the render surface.
        renderSurface->m_drawOpacity = layer->opacity();
        if (layer->parent() && layer->parent()->preserves3D())
            renderSurface->m_drawOpacity *= layer->parent()->drawOpacity();
        layer->setDrawOpacity(1);

        TransformationMatrix layerOriginTransform = combinedTransform;
        layerOriginTransform.translate3d(-0.5 * bounds.width(), -0.5 * bounds.height(), 0);
        renderSurface->m_originTransform = layerOriginTransform;
        layer->setScissorRect(IntRect());

        // The render surface scissor rect is the scissor rect that needs to
        // be applied before drawing the render surface onto its containing
        // surface and is therefore expressed in the parent's coordinate system.
        renderSurface->m_scissorRect = layer->parent() ? layer->parent()->scissorRect() : layer->scissorRect();

        renderSurface->m_layerList.clear();

        if (layer->maskLayer()) {
            renderSurface->m_maskLayer = layer->maskLayer();
            layer->maskLayer()->setTargetRenderSurface(renderSurface);
        } else
            renderSurface->m_maskLayer = 0;

        if (layer->replicaLayer() && layer->replicaLayer()->maskLayer())
            layer->replicaLayer()->maskLayer()->setTargetRenderSurface(renderSurface);

        renderSurfaceLayerList.append(layer);
    } else {
//.........这里部分代码省略.........

void LayerRendererChromium::updateLayers(LayerList& renderSurfaceLayerList)
{
    TRACE_EVENT("LayerRendererChromium::updateLayers", this, 0);
    CCLayerImpl* rootDrawLayer = m_rootLayer->ccLayerImpl();

    if (!rootDrawLayer->renderSurface())
        rootDrawLayer->createRenderSurface();
    ASSERT(rootDrawLayer->renderSurface());

    rootDrawLayer->renderSurface()->m_contentRect = IntRect(IntPoint(0, 0), m_viewportVisibleRect.size());

    IntRect rootScissorRect(m_viewportVisibleRect);
    // The scissorRect should not include the scroll offset.
    rootScissorRect.move(-m_viewportScrollPosition.x(), -m_viewportScrollPosition.y());
    rootDrawLayer->setScissorRect(rootScissorRect);

    m_defaultRenderSurface = rootDrawLayer->renderSurface();

    renderSurfaceLayerList.append(rootDrawLayer);

    TransformationMatrix identityMatrix;
    m_defaultRenderSurface->m_layerList.clear();
    // Unfortunately, updatePropertiesAndRenderSurfaces() currently both updates the layers and updates the draw state
    // (transforms, etc). It'd be nicer if operations on the presentation layers happened later, but the draw
    // transforms are needed by large layers to determine visibility. Tiling will fix this by eliminating the
    // concept of a large content layer.
    updatePropertiesAndRenderSurfaces(rootDrawLayer, identityMatrix, renderSurfaceLayerList, m_defaultRenderSurface->m_layerList);

#ifndef NDEBUG
    s_inPaintLayerContents = true;
#endif
    paintLayerContents(renderSurfaceLayerList);
#ifndef NDEBUG
    s_inPaintLayerContents = false;
#endif

    // FIXME: Before updateCompositorResourcesRecursive, when the compositor runs in
    // its own thread, and when the copyTexImage2D bug is fixed, insert
    // a glWaitLatch(Compositor->Offscreen) on all child contexts here instead
    // of after updateCompositorResourcesRecursive.
    // Also uncomment the glSetLatch(Compositor->Offscreen) code in addChildContext.
//  if (hardwareCompositing() && m_contextSupportsLatch) {
//      // For each child context:
//      //   glWaitLatch(Compositor->Offscreen);
//      ChildContextMap::iterator i = m_childContexts.begin();
//      for (; i != m_childContexts.end(); ++i) {
//          Extensions3DChromium* ext = static_cast<Extensions3DChromium*>(i->first->getExtensions());
//          GC3Duint childToParentLatchId, parentToChildLatchId;
//          ext->getParentToChildLatchCHROMIUM(&parentToChildLatchId);
//          ext->waitLatchCHROMIUM(parentToChildLatchId);
//      }
//  }

    updateCompositorResourcesRecursive(m_rootLayer.get());

    // After updateCompositorResourcesRecursive, set/wait latches for all child
    // contexts. This will prevent the compositor from using any of the child
    // parent textures while WebGL commands are executing from javascript *and*
    // while the final parent texture is being blit'd. copyTexImage2D
    // uses the parent texture as a temporary resolve buffer, so that's why the
    // waitLatch is below, to block the compositor from using the parent texture
    // until the next WebGL SwapBuffers (or copyTextureToParentTexture for
    // Canvas2D).
    if (hardwareCompositing() && m_contextSupportsLatch) {
        m_childContextsWereCopied = true;
        // For each child context:
        //   glSetLatch(Offscreen->Compositor);
        //   glWaitLatch(Compositor->Offscreen);
        ChildContextMap::iterator i = m_childContexts.begin();
        for (; i != m_childContexts.end(); ++i) {
            Extensions3DChromium* ext = static_cast<Extensions3DChromium*>(i->first->getExtensions());
            GC3Duint childToParentLatchId, parentToChildLatchId;
            ext->getParentToChildLatchCHROMIUM(&parentToChildLatchId);
            ext->getChildToParentLatchCHROMIUM(&childToParentLatchId);
            ext->setLatchCHROMIUM(childToParentLatchId);
            ext->waitLatchCHROMIUM(parentToChildLatchId);
        }
    }
}