Bug 993004 - Fix the clipping of tiles when the screen is rotated. r=botond

gfx/layers/Compositor.cpp

@@ -107,18 +107,33 @@ Compositor::DrawDiagnostics(DiagnosticFlags aFlags,
 gfx::Rect
 Compositor::ClipRectInLayersCoordinates(gfx::Rect aClip) const {
   gfx::Rect result;
+  aClip = aClip + GetCurrentRenderTarget()->GetOrigin();
+  gfx::IntSize destSize = GetWidgetSize();
+
   switch (mScreenRotation) {
-    case ROTATION_90:
-    case ROTATION_270:
-      result = gfx::Rect(aClip.y, aClip.x, aClip.height, aClip.width);
-      break;
     case ROTATION_0:
-    case ROTATION_180:
-    default:
       result = aClip;
       break;
+    case ROTATION_90:
+      result = gfx::Rect(aClip.y,
+                         destSize.width - aClip.x - aClip.width,
+                         aClip.height, aClip.width);
+      break;
+    case ROTATION_270:
+      result = gfx::Rect(destSize.height - aClip.y - aClip.height,
+                         aClip.x,
+                         aClip.height, aClip.width);
+      break;
+    case ROTATION_180:
+      result = gfx::Rect(destSize.width - aClip.x - aClip.width,
+                         destSize.height - aClip.y - aClip.height,
+                         aClip.width, aClip.height);
+      break;
+      // ScreenRotation has a sentinel value, need to catch it in the switch
+      // statement otherwise the build fails (-WError)
+    default: {}
   }
-  return result + GetCurrentRenderTarget()->GetOrigin();
+  return result;
 }
 
 void

gfx/layers/Compositor.h

@@ -500,6 +500,7 @@ public:
   // In addition, the clip rect needs to be offset by the rendering origin.
   // This becomes important if intermediate surfaces are used.
   gfx::Rect ClipRectInLayersCoordinates(gfx::Rect aClip) const;
+
 protected:
   void DrawDiagnosticsInternal(DiagnosticFlags aFlags,
                                const gfx::Rect& aVisibleRect,
@@ -528,6 +529,8 @@ protected:
 
   ScreenRotation mScreenRotation;
 
+  virtual gfx::IntSize GetWidgetSize() const = 0;
+
 private:
   static LayersBackend sBackend;
 

gfx/layers/basic/BasicCompositor.cpp

@@ -378,6 +378,7 @@ BasicCompositor::BeginFrame(const nsIntRegion& aInvalidRegion,
 {
   nsIntRect intRect;
   mWidget->GetClientBounds(intRect);
+  mWidgetSize = gfx::ToIntSize(intRect.Size());
 
   // The result of GetClientBounds is shifted over by the size of the window
   // manager styling. We want to ignore that.

gfx/layers/basic/BasicCompositor.h

@@ -125,9 +125,12 @@ public:
   gfx::DrawTarget *GetDrawTarget() { return mDrawTarget; }
 
 private:
+
+  virtual gfx::IntSize GetWidgetSize() const MOZ_OVERRIDE { return mWidgetSize; }
+
   // Widget associated with this compositor
   nsIWidget *mWidget;
-  nsIntSize mWidgetSize;
+  gfx::IntSize mWidgetSize;
 
   // The final destination surface
   RefPtr<gfx::DrawTarget> mDrawTarget;

gfx/layers/d3d11/CompositorD3D11.h

@@ -157,6 +157,8 @@ private:
   void SetPSForEffect(Effect *aEffect, MaskType aMaskType, gfx::SurfaceFormat aFormat);
   void PaintToTarget();
 
+  virtual gfx::IntSize GetWidgetSize() const MOZ_OVERRIDE { return gfx::ToIntSize(mSize); }
+
   RefPtr<ID3D11DeviceContext> mContext;
   RefPtr<ID3D11Device> mDevice;
   RefPtr<IDXGISwapChain> mSwapChain;

gfx/layers/d3d9/CompositorD3D9.h

@@ -153,6 +153,8 @@ private:
 
   void ReportFailure(const nsACString &aMsg, HRESULT aCode);
 
+  virtual gfx::IntSize GetWidgetSize() const MOZ_OVERRIDE { return mSize; }
+
   /* Device manager instance for this compositor */
   nsRefPtr<DeviceManagerD3D9> mDeviceManager;
 

gfx/layers/opengl/CompositorOGL.h

@@ -285,6 +285,11 @@ private:
                                 const gfx::Matrix4x4 &aTransformi,
                                 GLuint aDrawMode);
 
+  virtual gfx::IntSize GetWidgetSize() const MOZ_OVERRIDE
+  {
+    return gfx::ToIntSize(mWidgetSize);
+  }
+
   /**
    * Context target, nullptr when drawing directly to our swap chain.
    */