void CCDamageTracker::extendDamageForRenderSurface(CCLayerImpl* layer, FloatRect& targetDamageRect)
{
// There are two ways a "descendant surface" can damage regions of the "target surface":
// 1. Property change:
// - a surface's geometry can change because of
// - changes to descendants (i.e. the subtree) that affect the surface's content rect
// - changes to ancestor layers that propagate their property changes to their entire subtree.
// - just like layers, both the old surface rect and new surface rect will
// damage the target surface in this case.
//
// 2. Damage rect: This surface may have been damaged by its own layerList as well, and that damage
// should propagate to the target surface.
//
CCRenderSurface* renderSurface = layer->renderSurface();
bool surfaceIsNew = false;
FloatRect oldSurfaceRect = removeRectFromCurrentFrame(layer->id(), surfaceIsNew);
FloatRect surfaceRectInTargetSpace = renderSurface->drawableContentRect(); // already includes replica if it exists.
saveRectForNextFrame(layer->id(), surfaceRectInTargetSpace);
FloatRect damageRectInLocalSpace;
if (surfaceIsNew || renderSurface->surfacePropertyChanged() || layer->layerSurfacePropertyChanged()) {
// The entire surface contributes damage.
damageRectInLocalSpace = renderSurface->contentRect();
// The surface's old region is now exposed on the target surface, too.
targetDamageRect.uniteIfNonZero(oldSurfaceRect);
} else {
// Only the surface's damageRect will damage the target surface.
damageRectInLocalSpace = renderSurface->damageTracker()->currentDamageRect();
}
// If there was damage, transform it to target space, and possibly contribute its reflection if needed.
if (!damageRectInLocalSpace.isEmpty()) {
const WebTransformationMatrix& drawTransform = renderSurface->drawTransform();
FloatRect damageRectInTargetSpace = CCMathUtil::mapClippedRect(drawTransform, damageRectInLocalSpace);
targetDamageRect.uniteIfNonZero(damageRectInTargetSpace);
if (layer->replicaLayer()) {
const WebTransformationMatrix& replicaDrawTransform = renderSurface->replicaDrawTransform();
targetDamageRect.uniteIfNonZero(CCMathUtil::mapClippedRect(replicaDrawTransform, damageRectInLocalSpace));
}
}
// If there was damage on the replica's mask, then the target surface receives that damage as well.
if (layer->replicaLayer() && layer->replicaLayer()->maskLayer()) {
CCLayerImpl* replicaMaskLayer = layer->replicaLayer()->maskLayer();
bool replicaIsNew = false;
removeRectFromCurrentFrame(replicaMaskLayer->id(), replicaIsNew);
const WebTransformationMatrix& replicaDrawTransform = renderSurface->replicaDrawTransform();
FloatRect replicaMaskLayerRect = CCMathUtil::mapClippedRect(replicaDrawTransform, FloatRect(FloatPoint::zero(), FloatSize(replicaMaskLayer->bounds().width(), replicaMaskLayer->bounds().height())));
saveRectForNextFrame(replicaMaskLayer->id(), replicaMaskLayerRect);
// In the current implementation, a change in the replica mask damages the entire replica region.
if (replicaIsNew || replicaMaskLayer->layerPropertyChanged() || !replicaMaskLayer->updateRect().isEmpty())
targetDamageRect.uniteIfNonZero(replicaMaskLayerRect);
}
// If the layer has a background filter, this may cause pixels in our surface to be expanded, so we will need to expand any damage
// at or below this layer. We expand the damage from this layer too, as we need to readback those pixels from the surface with only
// the contents of layers below this one in them. This means we need to redraw any pixels in the surface being used for the blur in
// this layer this frame.
if (layer->backgroundFilters().hasFilterThatMovesPixels())
expandDamageRectInsideRectWithFilters(targetDamageRect, surfaceRectInTargetSpace, layer->backgroundFilters());
}
