Bug 717393 - Part 5: Permit subpixel AA for transparent surfaces. r=roc

gfx/layers/basic/BasicLayers.cpp

@@ -599,21 +599,33 @@ static void
 SetAntialiasingFlags(Layer* aLayer, gfxContext* aTarget)
 {
   if (!aTarget->IsCairo()) {
-    // Azure targets don't contain antialiasing flags at this point.
-    return;
-  }
+    RefPtr<DrawTarget> dt = aTarget->GetDrawTarget();
 
-  nsRefPtr<gfxASurface> surface = aTarget->CurrentSurface();
-  if (surface->GetContentType() != gfxASurface::CONTENT_COLOR_ALPHA) {
-    // Destination doesn't have alpha channel; no need to set any special flags
-    return;
-  }
+    if (dt->GetFormat() != FORMAT_B8G8R8A8) {
+      return;
+    }
 
-  const nsIntRect& bounds = aLayer->GetVisibleRegion().GetBounds();
-  surface->SetSubpixelAntialiasingEnabled(
-      !(aLayer->GetContentFlags() & Layer::CONTENT_COMPONENT_ALPHA) ||
-      surface->GetOpaqueRect().Contains(
-        aTarget->UserToDevice(gfxRect(bounds.x, bounds.y, bounds.width, bounds.height))));
+    const nsIntRect& bounds = aLayer->GetVisibleRegion().GetBounds();
+    Rect transformedBounds = dt->GetTransform().TransformBounds(Rect(Float(bounds.x), Float(bounds.y),
+                                                                     Float(bounds.width), Float(bounds.height)));
+    transformedBounds.RoundOut();
+    IntRect intTransformedBounds;
+    transformedBounds.ToIntRect(&intTransformedBounds);
+    dt->SetPermitSubpixelAA(!(aLayer->GetContentFlags() & Layer::CONTENT_COMPONENT_ALPHA) ||
+                            dt->GetOpaqueRect().Contains(intTransformedBounds));
+  } else {
+    nsRefPtr<gfxASurface> surface = aTarget->CurrentSurface();
+    if (surface->GetContentType() != gfxASurface::CONTENT_COLOR_ALPHA) {
+      // Destination doesn't have alpha channel; no need to set any special flags
+      return;
+    }
+
+    const nsIntRect& bounds = aLayer->GetVisibleRegion().GetBounds();
+    surface->SetSubpixelAntialiasingEnabled(
+        !(aLayer->GetContentFlags() & Layer::CONTENT_COMPONENT_ALPHA) ||
+        surface->GetOpaqueRect().Contains(
+          aTarget->UserToDevice(gfxRect(bounds.x, bounds.y, bounds.width, bounds.height))));
+  }
 }
 
 already_AddRefed<gfxContext>

gfx/layers/d3d10/ThebesLayerD3D10.cpp

@@ -484,6 +484,8 @@ ThebesLayerD3D10::DrawRegion(nsIntRegion &aRegion, SurfaceMode aMode)
 
   if (mD2DSurface) {
     mD2DSurface->SetSubpixelAntialiasingEnabled(!(mContentFlags & CONTENT_COMPONENT_ALPHA));
+  } else if (mDrawTarget) {
+    mDrawTarget->SetPermitSubpixelAA(!(mContentFlags & CONTENT_COMPONENT_ALPHA));
   }
 
   LayerManagerD3D10::CallbackInfo cbInfo = mD3DManager->GetCallbackInfo();

gfx/thebes/gfxContext.h

@@ -930,23 +930,33 @@ public:
     gfxContextAutoDisableSubpixelAntialiasing(gfxContext *aContext, bool aDisable)
     {
         if (aDisable) {
-            mSurface = aContext->CurrentSurface();
-            if (!mSurface) {
-              return;
+            if (aContext->IsCairo()) {
+                mSurface = aContext->CurrentSurface();
+                if (!mSurface) {
+                  return;
+                }
+                mSubpixelAntialiasingEnabled = mSurface->GetSubpixelAntialiasingEnabled();
+                mSurface->SetSubpixelAntialiasingEnabled(false);
+            } else {
+                mDT = aContext->GetDrawTarget();
+
+                mSubpixelAntialiasingEnabled = mDT->GetPermitSubpixelAA();
+                mDT->SetPermitSubpixelAA(false);
             }
-            mSubpixelAntialiasingEnabled = mSurface->GetSubpixelAntialiasingEnabled();
-            mSurface->SetSubpixelAntialiasingEnabled(false);
         }
     }
     ~gfxContextAutoDisableSubpixelAntialiasing()
     {
         if (mSurface) {
             mSurface->SetSubpixelAntialiasingEnabled(mSubpixelAntialiasingEnabled);
+        } else if (mDT) {
+            mDT->SetPermitSubpixelAA(mSubpixelAntialiasingEnabled);
         }
     }
 
 private:
     nsRefPtr<gfxASurface> mSurface;
+    mozilla::RefPtr<mozilla::gfx::DrawTarget> mDT;
     bool mSubpixelAntialiasingEnabled;
 };