Bug 717921. Only have one thebes surface. r=bas

--HG--
extra : rebase_source : 731cfa7d20fec10b784118297e7223e2e9279773

gfx/thebes/gfxPlatform.cpp

@@ -532,9 +532,26 @@ DataSourceSurfaceDestroy(void *dataSourceSurface)
       static_cast<DataSourceSurface*>(dataSourceSurface)->Release();
 }
 
+void DestroyThebesSurface(void *data)
+{
+  gfxASurface *surface = static_cast<gfxASurface*>(data);
+  surface->Release();
+}
+
+UserDataKey ThebesSurfaceKey;
+
+// The semantics of this function are sort of weird. We snapshot the first
+// time and then return the snapshotted surface for the lifetime of the
+// draw target
 already_AddRefed<gfxASurface>
 gfxPlatform::GetThebesSurfaceForDrawTarget(DrawTarget *aTarget)
 {
+  void *surface = aTarget->GetUserData(&ThebesSurfaceKey);
+  if (surface) {
+    nsRefPtr<gfxASurface> surf = static_cast<gfxASurface*>(surface);
+    return surf.forget();
+  }
+
   RefPtr<SourceSurface> source = aTarget->Snapshot();
   RefPtr<DataSourceSurface> data = source->GetDataSurface();
 
@@ -545,12 +562,18 @@ gfxPlatform::GetThebesSurfaceForDrawTarget(DrawTarget *aTarget)
   IntSize size = data->GetSize();
   gfxASurface::gfxImageFormat format = gfxASurface::FormatFromContent(ContentForFormat(data->GetFormat()));
   
-  nsRefPtr<gfxImageSurface> image =
+  nsRefPtr<gfxImageSurface> surf =
     new gfxImageSurface(data->GetData(), gfxIntSize(size.width, size.height),
                         data->Stride(), format);
 
-  image->SetData(&kDrawSourceSurface, data.forget().drop(), DataSourceSurfaceDestroy);
-  return image.forget();
+  surf->SetData(&kDrawSourceSurface, data.forget().drop(), DataSourceSurfaceDestroy);
+
+  // add a reference to be held by the drawTarget
+  // careful, the reference graph is getting complicated here
+  surf->AddRef();
+  aTarget->AddUserData(&ThebesSurfaceKey, surf.get(), DestroyThebesSurface);
+
+  return surf.forget();
 }
 
 RefPtr<DrawTarget>

gfx/thebes/gfxPlatform.h

@@ -71,6 +71,9 @@ class gfxTextRun;
 class nsIURI;
 class nsIAtom;
 
+extern mozilla::gfx::UserDataKey ThebesSurfaceKey;
+void DestroyThebesSurface(void *data);
+
 extern cairo_user_data_key_t kDrawTarget;
 
 // pref lang id's for font prefs

gfx/thebes/gfxPlatformMac.cpp

@@ -303,6 +303,11 @@ already_AddRefed<gfxASurface>
 gfxPlatformMac::GetThebesSurfaceForDrawTarget(DrawTarget *aTarget)
 {
   if (aTarget->GetType() == BACKEND_COREGRAPHICS) {
+    void *surface = aTarget->GetUserData(&ThebesSurfaceKey);
+    if (surface) {
+      nsRefPtr<gfxASurface> surf = static_cast<gfxQuartzSurface*>(surface);
+      return surf.forget();
+    } else {
       CGContextRef cg = static_cast<CGContextRef>(aTarget->GetNativeSurface(NATIVE_SURFACE_CGCONTEXT));
 
       //XXX: it would be nice to have an implicit conversion from IntSize to gfxIntSize
@@ -312,8 +317,13 @@ gfxPlatformMac::GetThebesSurfaceForDrawTarget(DrawTarget *aTarget)
       nsRefPtr<gfxASurface> surf =
         new gfxQuartzSurface(cg, size);
 
+      // add a reference to be held by the drawTarget
+      surf->AddRef();
+      aTarget->AddUserData(&ThebesSurfaceKey, surf.get(), DestroyThebesSurface);
+
       return surf.forget();
     }
+  }
 
   return gfxPlatform::GetThebesSurfaceForDrawTarget(aTarget);
 }

gfx/thebes/gfxWindowsPlatform.cpp

@@ -507,6 +507,11 @@ gfxWindowsPlatform::GetThebesSurfaceForDrawTarget(DrawTarget *aTarget)
 {
 #ifdef XP_WIN
   if (aTarget->GetType() == BACKEND_DIRECT2D) {
+    void *surface = aTarget->GetUserData(&ThebesSurfaceKey);
+    if (surface) {
+      nsRefPtr<gfxASurface> surf = static_cast<gfxASurface*>(surface);
+      return surf.forget();
+    } else {
       RefPtr<ID3D10Texture2D> texture =
         static_cast<ID3D10Texture2D*>(aTarget->GetNativeSurface(NATIVE_SURFACE_D3D10_TEXTURE));
 
@@ -519,11 +524,19 @@ gfxWindowsPlatform::GetThebesSurfaceForDrawTarget(DrawTarget *aTarget)
       nsRefPtr<gfxASurface> surf =
         new gfxD2DSurface(texture, ContentForFormat(aTarget->GetFormat()));
 
+      // add a reference to be held by the drawTarget
+      surf->AddRef();
+      aTarget->AddUserData(&ThebesSurfaceKey, surf.get(), DestroyThebesSurface);
+      /* "It might be worth it to clear cairo surfaces associated with a drawtarget.
+	  The strong reference means for example for D2D that cairo's scratch surface
+	  will be kept alive (well after a user being done) and consume extra VRAM.
+	  We can deal with this in a follow-up though." */
+
       // shouldn't this hold a reference?
       surf->SetData(&kDrawTarget, aTarget, NULL);
-
       return surf.forget();
     }
+  }
 #endif
 
   return gfxPlatform::GetThebesSurfaceForDrawTarget(aTarget);