Fixes toDataURL for GL by making it all work through

O3D.

What happens is client.toDataURL creates a RenderSurface
and DepthSurface, sets those as the current Surface
then renders. It then calls Surface::GetBitmap to 
get the pixels in the bitmap.

The complications are

1) I needed to make Renderer::StartRendering / 
Renderer::FinishRendering be nestable because the
Renderer::SetRenderSurface required StartRendering
to already have been called. I didn't see a cleaner
way to do this but I'm happy to change it if you
have a better idea.

2) Since we can only create POT RenderSurfaces
I added a clip_width / clip_height to render surfaces.
Renderer::SetViewport uses these values so we end up
rendering correctly to the top/left area of the
POT render surface.

3) Doing it this way means that screenshots are NOT
anti-aliased.  I feel like that issue can be handled
later. It's more important that toDataURL work now
than it have the ultimate best results. (I hope). It
probably means I'll need to create all new reference
images.

4) I was wondering we we should expose SetClipWidth
to JavaScript. Given that we require POT render surfaces
they should always get the same results on all hardware.
Or, rather, we could just allow the user to create NPOT
RenderSurfaces. Under the hood they'd get a POT surface
but the clip_width/clip_height would be set to the size
the requested. There would have to be a note that texture
wrapping only works if the size if POT.

5) I had to split FinishRendering into FinishRendering
and Present since when taking a screenshot nothing will
be drawn to the backbuffer and so I don't want a 
present to happen.


Review URL: http://codereview.chromium.org/174594

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@24781 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 24 insertions, 28 deletions

diff --git a/o3d/converter/cross/renderer_stub.cc b/o3d/converter/cross/renderer_stub.cc
index 691c1ce..2801470 100644
--- a/o3d/converter/cross/renderer_stub.cc
+++ b/o3d/converter/cross/renderer_stub.cc
@@ -95,25 +95,22 @@ void RendererStub::Resize(int, int) {
   DCHECK(false);
 }
 
-void RendererStub::Clear(const Float4 &, bool, float, bool, int, bool) {
+void RendererStub::PlatformSpecificClear(
+  const Float4 &, bool, float, bool, int, bool) {
   DCHECK(false);
 }
 
-void RendererStub::RenderElement(Element *,
-                                 DrawElement *,
-                                 Material *,
-                                 ParamObject *,
-                                 ParamCache *) {
+void RendererStub::SetRenderSurfacesPlatformSpecific(
+    const RenderSurface* surface,
+    const RenderDepthStencilSurface* surface_depth) {
   DCHECK(false);
 }
 
-void RendererStub::SetRenderSurfacesPlatformSpecific(
-    RenderSurface* surface,
-    RenderDepthStencilSurface* surface_depth) {
+void RendererStub::SetBackBufferPlatformSpecific() {
   DCHECK(false);
 }
 
-void RendererStub::SetBackBufferPlatformSpecific() {
+void RendererStub::ApplyDirtyStates() {
   DCHECK(false);
 }
 
@@ -178,10 +175,6 @@ StreamBank::Ref RendererStub::CreateStreamBank() {
   return StreamBank::Ref(new StreamBankStub(service_locator()));
 }
 
-Bitmap::Ref RendererStub::PlatformSpecificTakeScreenshot() {
-  return Bitmap::Ref();
-}
-
 ParamCache *RendererStub::CreatePlatformSpecificParamCache(void) {
   return new ParamCacheStub;
 }
@@ -190,6 +183,9 @@ void RendererStub::SetViewportInPixels(int, int, int, int, float, float) {
   DCHECK(false);
 }
 
+void RendererStub::PlatformSpecificPresent(void) {
+}
+
 const int* RendererStub::GetRGBAUByteNSwizzleTable() {
   static int swizzle_table[] = { 0, 1, 2, 3, };
   return swizzle_table;
diff --git a/o3d/converter/cross/renderer_stub.h b/o3d/converter/cross/renderer_stub.h
index a4bd205..3f0c413 100644
--- a/o3d/converter/cross/renderer_stub.h
+++ b/o3d/converter/cross/renderer_stub.h
@@ -55,17 +55,6 @@ class RendererStub : public Renderer {
   virtual void UninitCommon();
   virtual void Destroy();
   virtual void Resize(int width, int height);
-  virtual void Clear(const Float4 &color,
-                     bool color_flag,
-                     float depth,
-                     bool depth_flag,
-                     int stencil,
-                     bool stencil_flag);
-  virtual void RenderElement(Element* element,
-                             DrawElement* draw_element,
-                             Material* material,
-                             ParamObject* override,
-                             ParamCache* param_cache);
   virtual Primitive::Ref CreatePrimitive();
   virtual DrawElement::Ref CreateDrawElement();
   virtual VertexBuffer::Ref CreateVertexBuffer();
@@ -102,15 +91,26 @@ class RendererStub : public Renderer {
   virtual void PlatformSpecificFinishRendering();
 
   // Overridden from Renderer.
-  virtual Bitmap::Ref PlatformSpecificTakeScreenshot();
+  virtual void PlatformSpecificPresent();
+
+  // Overridden from Renderer.
+  virtual void PlatformSpecificClear(const Float4 &color,
+                                     bool color_flag,
+                                     float depth,
+                                     bool depth_flag,
+                                     int stencil,
+                                     bool stencil_flag);
 
   // Overridden from Renderer.
   virtual void SetBackBufferPlatformSpecific();
 
   // Overridden from Renderer.
+  virtual void ApplyDirtyStates();
+
+  // Overridden from Renderer.
   virtual void SetRenderSurfacesPlatformSpecific(
-      RenderSurface* surface,
-      RenderDepthStencilSurface* depth_surface);
+      const RenderSurface* surface,
+      const RenderDepthStencilSurface* depth_surface);
 
   // Overridden from Renderer.
   virtual Texture2D::Ref CreatePlatformSpecificTexture2D(