Bug 1036604 - add VR display item and VR frame state bit; r=roc

layout/base/nsDisplayList.cpp

@@ -5660,6 +5660,31 @@ nsDisplaySVGEffects::~nsDisplaySVGEffects()
 }
 #endif
 
+nsDisplayVR::nsDisplayVR(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
+                         nsDisplayList* aList, mozilla::gfx::VRHMDInfo* aHMD)
+  : nsDisplayOwnLayer(aBuilder, aFrame, aList)
+  , mHMD(aHMD)
+{
+}
+
+already_AddRefed<Layer>
+nsDisplayVR::BuildLayer(nsDisplayListBuilder* aBuilder,
+                        LayerManager* aManager,
+                        const ContainerLayerParameters& aContainerParameters)
+{
+  ContainerLayerParameters newContainerParameters = aContainerParameters;
+  uint32_t flags = FrameLayerBuilder::CONTAINER_NOT_CLIPPED_BY_ANCESTORS;
+  nsRefPtr<ContainerLayer> container = aManager->GetLayerBuilder()->
+    BuildContainerLayerFor(aBuilder, aManager, mFrame, this, &mList,
+                           newContainerParameters, nullptr, flags);
+
+  // This gets uncommented when it's implemented by the layers functionality patch
+  //container->SetVRHMDInfo(mHMD);
+  container->SetUserData(nsIFrame::LayerIsPrerenderedDataKey(),
+                         /*the value is irrelevant*/nullptr);
+
+  return container.forget();
+}
 nsRegion nsDisplaySVGEffects::GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
                                               bool* aSnap)
 {

layout/base/nsDisplayList.h

@@ -28,6 +28,7 @@
 #include "FrameMetrics.h"
 #include "mozilla/UniquePtr.h"
 #include "mozilla/gfx/UserData.h"
+#include "gfxVR.h"
 
 #include <stdint.h>
 #include "nsTHashtable.h"
@@ -3616,4 +3617,29 @@ public:
   nscoord mRightEdge; // length from the right side
 };
 
+/**
+ * A wrapper layer that wraps its children in a container, then renders
+ * everything with an appropriate VR effect based on the HMDInfo.
+ */
+
+class nsDisplayVR : public nsDisplayOwnLayer {
+public:
+  nsDisplayVR(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
+              nsDisplayList* aList, mozilla::gfx::VRHMDInfo* aHMD);
+
+  virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
+                                   LayerManager* aManager,
+                                   const ContainerLayerParameters& aParameters) MOZ_OVERRIDE
+  {
+    return mozilla::LAYER_ACTIVE;
+  }
+
+  virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
+                                             LayerManager* aManager,
+                                             const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE;
+
+protected:
+  nsRefPtr<mozilla::gfx::VRHMDInfo> mHMD;
+};
+
 #endif /*NSDISPLAYLIST_H_*/

layout/generic/nsFrame.cpp

@@ -102,6 +102,12 @@ using namespace mozilla::gfx;
 using namespace mozilla::layers;
 using namespace mozilla::layout;
 
+namespace mozilla {
+namespace gfx {
+class VRHMDInfo;
+}
+}
+
 // Struct containing cached metrics for box-wrapped frames.
 struct nsBoxLayoutMetrics
 {
@@ -590,6 +596,10 @@ nsFrame::Init(nsIContent*       aContent,
                  "root frame should always be a container");
   }
 
+  if (aContent && aContent->GetProperty(nsGkAtoms::vr_state) != nullptr) {
+    AddStateBits(NS_FRAME_HAS_VR_CONTENT);
+  }
+
   DidSetStyleContext(nullptr);
 
   if (::IsBoxWrapped(this))
@@ -1995,6 +2005,12 @@ nsIFrame::BuildDisplayListForStackingContext(nsDisplayListBuilder* aBuilder,
 
   nsDisplayListBuilder::AutoBuildingDisplayList
     buildingDisplayList(aBuilder, this, dirtyRect, true);
+
+  mozilla::gfx::VRHMDInfo* vrHMDInfo = nullptr;
+  if ((GetStateBits() & NS_FRAME_HAS_VR_CONTENT)) {
+    vrHMDInfo = static_cast<mozilla::gfx::VRHMDInfo*>(mContent->GetProperty(nsGkAtoms::vr_state));
+  }
+
   DisplayListClipState::AutoSaveRestore clipState(aBuilder);
 
   if (isTransformed || useOpacity || useBlendMode || usingSVGEffects || useStickyPosition) {
@@ -2155,6 +2171,13 @@ nsIFrame::BuildDisplayListForStackingContext(nsDisplayListBuilder* aBuilder,
     }
   }
 
+  /* If we're doing VR rendering, then we need to wrap everything in a nsDisplayVR
+   */
+  if (vrHMDInfo && !resultList.IsEmpty()) {
+    resultList.AppendNewToTop(
+      new (aBuilder) nsDisplayVR(aBuilder, this, &resultList, vrHMDInfo));
+  }
+
   /* If adding both a nsDisplayBlendContainer and a nsDisplayMixBlendMode to the
    * same list, the nsDisplayBlendContainer should be added first. This only
    * happens when the element creating this stacking context has mix-blend-mode
@@ -2325,7 +2348,8 @@ nsIFrame::BuildDisplayListForChild(nsDisplayListBuilder*   aBuilder,
     // but the spec says it acts like the rest of these
     || disp->mChildPerspective.GetUnit() == eStyleUnit_Coord
     || disp->mMixBlendMode != NS_STYLE_BLEND_NORMAL
-    || nsSVGIntegrationUtils::UsingEffectsForFrame(child);
+    || nsSVGIntegrationUtils::UsingEffectsForFrame(child)
+    || (child->GetStateBits() & NS_FRAME_HAS_VR_CONTENT);
 
   bool isPositioned = disp->IsPositioned(child);
   bool isStackingContext =

layout/generic/nsFrameStateBits.h

@@ -249,6 +249,9 @@ FRAME_STATE_BIT(Generic, 53, NS_FRAME_IS_NONDISPLAY)
 // Frame has a LayerActivityProperty property
 FRAME_STATE_BIT(Generic, 54, NS_FRAME_HAS_LAYER_ACTIVITY_PROPERTY)
 
+// Frame has VR content, and needs VR display items created
+FRAME_STATE_BIT(Generic, 57, NS_FRAME_HAS_VR_CONTENT)
+
 // Set for all descendants of MathML sub/supscript elements (other than the
 // base frame) to indicate that the SSTY font feature should be used.
 FRAME_STATE_BIT(Generic, 58, NS_FRAME_MATHML_SCRIPT_DESCENDANT)