Fix ripples projecting to scrolled view

bug:16873774

1) Fix projectionReceiveIndex, which could in some cases point at
translate/restore ops.

2) Use background translateX / translateY for projected RenderNodes.
This makes them match background position, and thus properly account
for scroll.

Change-Id: Idbd5700858fd67c5abea0270a1012952fe09ac22

libs/hwui/DisplayListRenderer.cpp

@@ -176,15 +176,15 @@ bool DisplayListRenderer::clipRegion(const SkRegion* region, SkRegion::Op op) {
 status_t DisplayListRenderer::drawRenderNode(RenderNode* renderNode, Rect& dirty, int32_t flags) {
     // dirty is an out parameter and should not be recorded,
     // it matters only when replaying the display list
+    DrawRenderNodeOp* op = new (alloc()) DrawRenderNodeOp(renderNode, flags, *currentTransform());
+    int opIndex = addDrawOp(op);
+    mDisplayListData->addChild(op);
 
     if (renderNode->stagingProperties().isProjectionReceiver()) {
         // use staging property, since recording on UI thread
-        mDisplayListData->projectionReceiveIndex = mDisplayListData->displayListOps.size();
+        mDisplayListData->projectionReceiveIndex = opIndex;
     }
 
-    DrawRenderNodeOp* op = new (alloc()) DrawRenderNodeOp(renderNode, flags, *currentTransform());
-    addDrawOp(op);
-    mDisplayListData->addChild(op);
     return DrawGlInfo::kStatusDone;
 }
 
@@ -447,11 +447,11 @@ void DisplayListRenderer::insertTranslate() {
     }
 }
 
-void DisplayListRenderer::addStateOp(StateOp* op) {
-    addOpInternal(op);
+int DisplayListRenderer::addStateOp(StateOp* op) {
+    return addOpInternal(op);
 }
 
-void DisplayListRenderer::addDrawOp(DrawOp* op) {
+int DisplayListRenderer::addDrawOp(DrawOp* op) {
     Rect localBounds;
     if (op->getLocalBounds(localBounds)) {
         bool rejected = quickRejectConservative(localBounds.left, localBounds.top,
@@ -460,7 +460,7 @@ void DisplayListRenderer::addDrawOp(DrawOp* op) {
     }
 
     mDisplayListData->hasDrawOps = true;
-    addOpInternal(op);
+    return addOpInternal(op);
 }
 
 }; // namespace uirenderer

libs/hwui/DisplayListRenderer.h

@@ -158,12 +158,14 @@ private:
     void insertTranslate();
 
     LinearAllocator& alloc() { return mDisplayListData->allocator; }
-    void addStateOp(StateOp* op);
-    void addDrawOp(DrawOp* op);
-    void addOpInternal(DisplayListOp* op) {
+
+    // Each method returns final index of op
+    int addStateOp(StateOp* op);
+    int addDrawOp(DrawOp* op);
+    int addOpInternal(DisplayListOp* op) {
         insertRestoreToCount();
         insertTranslate();
-        mDisplayListData->displayListOps.add(op);
+        return mDisplayListData->displayListOps.add(op);
     }
 
     template<class T>

libs/hwui/RenderNode.cpp

@@ -741,15 +741,24 @@ void RenderNode::issueOperationsOfProjectedChildren(OpenGLRenderer& renderer, T&
     const SkPath* projectionReceiverOutline = properties().getOutline().getPath();
     int restoreTo = renderer.getSaveCount();
 
+    LinearAllocator& alloc = handler.allocator();
+    handler(new (alloc) SaveOp(SkCanvas::kMatrix_SaveFlag | SkCanvas::kClip_SaveFlag),
+            PROPERTY_SAVECOUNT, properties().getClipToBounds());
+
+    // Transform renderer to match background we're projecting onto
+    // (by offsetting canvas by translationX/Y of background rendernode, since only those are set)
+    const DisplayListOp* op =
+            (mDisplayListData->displayListOps[mDisplayListData->projectionReceiveIndex]);
+    const DrawRenderNodeOp* backgroundOp = reinterpret_cast<const DrawRenderNodeOp*>(op);
+    const RenderProperties& backgroundProps = backgroundOp->mRenderNode->properties();
+    renderer.translate(backgroundProps.getTranslationX(), backgroundProps.getTranslationY());
+
     // If the projection reciever has an outline, we mask each of the projected rendernodes to it
     // Either with clipRect, or special saveLayer masking
-    LinearAllocator& alloc = handler.allocator();
     if (projectionReceiverOutline != NULL) {
         const SkRect& outlineBounds = projectionReceiverOutline->getBounds();
         if (projectionReceiverOutline->isRect(NULL)) {
             // mask to the rect outline simply with clipRect
-            handler(new (alloc) SaveOp(SkCanvas::kMatrix_SaveFlag | SkCanvas::kClip_SaveFlag),
-                    PROPERTY_SAVECOUNT, properties().getClipToBounds());
             ClipRectOp* clipOp = new (alloc) ClipRectOp(
                     outlineBounds.left(), outlineBounds.top(),
                     outlineBounds.right(), outlineBounds.bottom(), SkRegion::kIntersect_Op);