Bug 640082 - Part 3 - Add BindTexture functions to TextureImage. r=joe

gfx/layers/opengl/ThebesLayerOGL.cpp

@@ -210,14 +210,8 @@ ThebesLayerBufferOGL::RenderTo(const nsIntPoint& aOffset,
   }
 
   // Bind textures.
-  gl()->fActiveTexture(LOCAL_GL_TEXTURE0);
-  gl()->fBindTexture(LOCAL_GL_TEXTURE_2D, mTexImage->Texture());
-
-  if (mTexImageOnWhite) {
-    gl()->fActiveTexture(LOCAL_GL_TEXTURE1);
-    gl()->fBindTexture(LOCAL_GL_TEXTURE_2D, mTexImageOnWhite->Texture());
-    gl()->fActiveTexture(LOCAL_GL_TEXTURE0);
-  }
+  TextureImage::ScopedBindTexture(mTexImage, LOCAL_GL_TEXTURE0);
+  TextureImage::ScopedBindTexture(mTexImageOnWhite, LOCAL_GL_TEXTURE1);
 
   float xres = mLayer->GetXResolution();
   float yres = mLayer->GetYResolution();
@@ -295,7 +289,7 @@ ThebesLayerBufferOGL::RenderTo(const nsIntPoint& aOffset,
     // Restore defaults
     gl()->fBlendFuncSeparate(LOCAL_GL_ONE, LOCAL_GL_ONE_MINUS_SRC_ALPHA,
                              LOCAL_GL_ONE, LOCAL_GL_ONE);
-   }
+  }
 }
 
 

gfx/thebes/GLContext.cpp

@@ -629,6 +629,14 @@ BasicTextureImage::EndUpdate()
     mTextureState = Valid;
 }
 
+void
+BasicTextureImage::BindTexture(GLenum aTextureUnit)
+{
+    mGLContext->fActiveTexture(aTextureUnit);
+    mGLContext->fBindTexture(LOCAL_GL_TEXTURE_2D, Texture());
+    mGLContext->fActiveTexture(LOCAL_GL_TEXTURE0);
+}
+
 already_AddRefed<gfxASurface>
 BasicTextureImage::GetSurfaceForUpdate(const gfxIntSize& aSize, ImageFormat aFmt)
 {

gfx/thebes/GLContext.h

@@ -205,6 +205,31 @@ public:
 
     virtual bool DirectUpdate(gfxASurface *aSurf, const nsIntRegion& aRegion) =0;
 
+    virtual void BindTexture(GLenum aTextureUnit) = 0;
+    virtual void ReleaseTexture() {};
+
+    class ScopedBindTexture
+    {
+    public:
+        ScopedBindTexture(TextureImage *aTexture, GLenum aTextureUnit) :
+          mTexture(aTexture)
+        {
+            if (mTexture) {
+                mTexture->BindTexture(aTextureUnit);
+            }
+        }
+
+        ~ScopedBindTexture()
+        {
+            if (mTexture) {
+                mTexture->ReleaseTexture();
+            }       
+        }
+
+    private:
+        TextureImage *mTexture;
+    };
+
     /**
      * Return this TextureImage's texture ID for use with GL APIs.
      * Callers are responsible for properly binding the texture etc.
@@ -302,6 +327,8 @@ public:
       Initialized,  // Texture memory exists, but contents are invalid.
       Valid  // Texture fully ready to use.
     };
+    
+    virtual void BindTexture(GLenum aTextureUnit);
 
     virtual gfxASurface* BeginUpdate(nsIntRegion& aRegion);
     virtual void EndUpdate();

gfx/thebes/GLContextProviderEGL.cpp

@@ -1266,6 +1266,13 @@ public:
         return true;
     }
 
+    virtual void BindTexture(GLenum aTextureUnit)
+    {
+        mGLContext->fActiveTexture(aTextureUnit);
+        mGLContext->fBindTexture(LOCAL_GL_TEXTURE_2D, Texture());
+        mGLContext->fActiveTexture(LOCAL_GL_TEXTURE0);
+    }
+
     virtual PRBool InUpdate() const { return !!mUpdateSurface; }
 
     virtual void Resize(const nsIntSize& aSize)