From b058c7e33367d415173c5a3c07607f5d3b3ebf02 Mon Sep 17 00:00:00 2001
From: Bas Schouten <bschouten@mozilla.com>
Date: Thu, 3 May 2012 23:31:02 +0200
Subject: [PATCH] Bug 738413 - Part 2: Use OpaqueRect API in BasicLayers with
 non-cairo contexts. r=roc

---
 gfx/layers/basic/BasicLayers.cpp | 55 +++++++++++++++++++++++++-------
 gfx/thebes/gfxUtils.cpp          |  8 +++++
 gfx/thebes/gfxUtils.h            |  7 ++++
 3 files changed, 58 insertions(+), 12 deletions(-)

diff --git a/gfx/layers/basic/BasicLayers.cpp b/gfx/layers/basic/BasicLayers.cpp
index b2202741ac51..eed08a5c38fb 100644
--- a/gfx/layers/basic/BasicLayers.cpp
+++ b/gfx/layers/basic/BasicLayers.cpp
@@ -74,6 +74,8 @@
 #define PIXMAN_DONT_DEFINE_STDINT
 #include "pixman.h"
 
+using namespace mozilla::gfx;
+
 namespace mozilla {
 namespace layers {
 
@@ -1946,19 +1948,40 @@ BasicLayerManager::PaintLayer(gfxContext* aTarget,
 
   bool pushedTargetOpaqueRect = false;
   nsRefPtr<gfxASurface> currentSurface = aTarget->CurrentSurface();
+  DrawTarget *dt = aTarget->GetDrawTarget();
   const nsIntRect& bounds = visibleRegion.GetBounds();
   
-  if (aTarget->IsCairo()) {
-    const gfxRect& targetOpaqueRect = currentSurface->GetOpaqueRect();
+  if (is2D) {
+    if (aTarget->IsCairo()) {
+      const gfxRect& targetOpaqueRect = currentSurface->GetOpaqueRect();
 
-    // Try to annotate currentSurface with a region of pixels that have been
-    // (or will be) painted opaque, if no such region is currently set.
-    if (targetOpaqueRect.IsEmpty() && visibleRegion.GetNumRects() == 1 &&
-        (aLayer->GetContentFlags() & Layer::CONTENT_OPAQUE) &&
-        !transform.HasNonAxisAlignedTransform()) {
-      currentSurface->SetOpaqueRect(
-          aTarget->UserToDevice(gfxRect(bounds.x, bounds.y, bounds.width, bounds.height)));
-      pushedTargetOpaqueRect = true;
+      // Try to annotate currentSurface with a region of pixels that have been
+      // (or will be) painted opaque, if no such region is currently set.
+      if (targetOpaqueRect.IsEmpty() && visibleRegion.GetNumRects() == 1 &&
+          (aLayer->GetContentFlags() & Layer::CONTENT_OPAQUE) &&
+          !transform.HasNonAxisAlignedTransform()) {
+        currentSurface->SetOpaqueRect(
+            aTarget->UserToDevice(gfxRect(bounds.x, bounds.y, bounds.width, bounds.height)));
+        pushedTargetOpaqueRect = true;
+      }
+    } else {
+      const IntRect& targetOpaqueRect = dt->GetOpaqueRect();
+
+      // Try to annotate currentSurface with a region of pixels that have been
+      // (or will be) painted opaque, if no such region is currently set.
+      if (targetOpaqueRect.IsEmpty() && visibleRegion.GetNumRects() == 1 &&
+          (aLayer->GetContentFlags() & Layer::CONTENT_OPAQUE) &&
+          !transform.HasNonAxisAlignedTransform()) {
+
+        Rect opaqueRect = dt->GetTransform().TransformBounds(
+          Rect(bounds.x, bounds.y, bounds.width, bounds.height));
+        opaqueRect.RoundIn();
+        IntRect intOpaqueRect;
+        if (gfxUtils::RectToIntRect(opaqueRect, &intOpaqueRect)) {
+          aTarget->GetDrawTarget()->SetOpaqueRect(intOpaqueRect);
+          pushedTargetOpaqueRect = true;
+        }
+      }
     }
   }
 
@@ -1970,7 +1993,11 @@ BasicLayerManager::PaintLayer(gfxContext* aTarget,
                                                          gfxASurface::CONTENT_COLOR_ALPHA);
     if (!untransformedSurface) {
       if (pushedTargetOpaqueRect) {
-        currentSurface->SetOpaqueRect(gfxRect(0, 0, 0, 0));
+        if (aTarget->IsCairo()) {
+          currentSurface->SetOpaqueRect(gfxRect(0, 0, 0, 0));
+        } else {
+          dt->SetOpaqueRect(IntRect());
+        }
       }
       NS_ASSERTION(needsSaveRestore, "Should always need to restore with 3d transforms!");
       aTarget->Restore();
@@ -2085,7 +2112,11 @@ BasicLayerManager::PaintLayer(gfxContext* aTarget,
   }
 
   if (pushedTargetOpaqueRect) {
-    currentSurface->SetOpaqueRect(gfxRect(0, 0, 0, 0));
+    if (aTarget->IsCairo()) {
+      currentSurface->SetOpaqueRect(gfxRect(0, 0, 0, 0));
+    } else {
+      dt->SetOpaqueRect(IntRect());
+    }
   }
 
   if (needsSaveRestore) {
diff --git a/gfx/thebes/gfxUtils.cpp b/gfx/thebes/gfxUtils.cpp
index 5247b399d76c..11bf4337a164 100644
--- a/gfx/thebes/gfxUtils.cpp
+++ b/gfx/thebes/gfxUtils.cpp
@@ -574,6 +574,14 @@ gfxUtils::GfxRectToIntRect(const gfxRect& aIn, nsIntRect* aOut)
   return gfxRect(aOut->x, aOut->y, aOut->width, aOut->height).IsEqualEdges(aIn);
 }
 
+bool
+gfxUtils::RectToIntRect(const Rect& aIn, IntRect* aOut)
+{
+  *aOut = IntRect(int32_t(aIn.X()), int32_t(aIn.Y()),
+                  int32_t(aIn.Width()), int32_t(aIn.Height()));
+  return Rect(aOut->x, aOut->y, aOut->width, aOut->height).IsEqualEdges(aIn);
+}
+
 void
 gfxUtils::GetYCbCrToRGBDestFormatAndSize(const PlanarYCbCrImage::Data& aData,
                                          gfxASurface::gfxImageFormat& aSuggestedFormat,
diff --git a/gfx/thebes/gfxUtils.h b/gfx/thebes/gfxUtils.h
index 56ccfe6d4c24..46a5031749e1 100644
--- a/gfx/thebes/gfxUtils.h
+++ b/gfx/thebes/gfxUtils.h
@@ -125,6 +125,13 @@ public:
     */
     static bool GfxRectToIntRect(const gfxRect& aIn, nsIntRect* aOut);
 
+    /**
+     * If aIn can be represented exactly using an nsIntRect (i.e.
+     * integer-aligned edges and coordinates in the PRInt32 range) then we
+     * set aOut to that rectangle, otherwise return failure.
+    */
+    static bool RectToIntRect(const mozilla::gfx::Rect& aIn, mozilla::gfx::IntRect* aOut);
+
     /**
      * Return the smallest power of kScaleResolution (2) greater than or equal to
      * aVal.