Improve tracking of bound FBOs in GrGLGpu.

src/gpu/gl/GrGLGpu.h

Index: src/gpu/gl/GrGLGpu.h
diff --git a/src/gpu/gl/GrGLGpu.h b/src/gpu/gl/GrGLGpu.h
index b93080b70037d2b5a624b0b9996dc7b798adad12..1803033b929dd5a45604f24649ac02bdba065581 100644
--- a/src/gpu/gl/GrGLGpu.h
+++ b/src/gpu/gl/GrGLGpu.h
@@ -50,6 +50,8 @@ public:
         return static_cast<GrGLPathRendering*>(pathRendering());
     }
 
+    void willDeleteOrAbandonFramebuffer(GrGLFBO* fbo);

[egdaniel, 2015/02/25 16:21:34]

comment on when and why this needs to be called.

+
     void discard(GrRenderTarget*) SK_OVERRIDE;
 
     // Used by GrGLProgram and GrGLPathTexGenProgramEffects to configure OpenGL
@@ -246,9 +248,25 @@ private:
     // ensures that such operations don't negatively interact with tracking bound textures.
     void setScratchTextureUnit();
 
-    // bounds is region that may be modified and therefore has to be resolved.
-    // NULL means whole target. Can be an empty rect.
-    void flushRenderTarget(GrGLRenderTarget*, const SkIRect* bounds);
+    // Binds the render target, sets the viewport, tracks dirty are for resolve, and tracks whether
+    // mip maps need rebuilding. bounds is region that may be modified by the draw. NULL means whole
+    // target. Can be an empty rect.
+    void prepareToDrawToRenderTarget(GrGLRenderTarget*, const SkIRect* bounds);
+
+    // On older GLs there may not be separate FBO bindings for draw and read. In that case these
+    // alias each other.
+    enum FBOBinding {
+        kDraw_FBOBinding, // drawing or dst of blit
+        kRead_FBOBinding, // src of blit, read pixels.
+
+        kLast_FBOBinding = kRead_FBOBinding
+    };
+    static const int kFBOBindingCnt = kLast_FBOBinding + 1;

[egdaniel, 2015/02/25 16:21:34]

comment on why there is a +1 here? I'm assuming it is for the invalidBinding you
make later?

+
+    // binds the FBO and returns the GL enum of the framebuffer target it was bound to.
+    GrGLenum bindFBO(FBOBinding, const GrGLFBO*);
+
+    void setViewport(const GrGLIRect& viewport);
 
     void flushStencil(const GrStencilSettings&);
     void flushHWAAState(GrRenderTarget* rt, bool useHWAA, bool isLineDraw);
@@ -281,15 +299,14 @@ private:
     bool createRenderTargetObjects(const GrSurfaceDesc&, bool budgeted, GrGLuint texID, 
                                    GrGLRenderTarget::IDDesc*);
 
-    enum TempFBOTarget {
-        kSrc_TempFBOTarget,
-        kDst_TempFBOTarget
-    };
+    static const FBOBinding kInvalidFBOBinding = static_cast<FBOBinding>(-1);
 
-    GrGLuint bindSurfaceAsFBO(GrSurface* surface, GrGLenum fboTarget, GrGLIRect* viewport,
-                              TempFBOTarget tempFBOTarget);
+    // Binds a surface as an FBO. A temporary FBO ID may be used if the surface is not already
+    // a render target. Afterwards unbindSurfaceAsFBOForCopy must be called with the value returned.
+    FBOBinding bindSurfaceAsFBOForCopy(GrSurface*, FBOBinding, GrGLIRect* viewport);
 
-    void unbindTextureFromFBO(GrGLenum fboTarget);
+    // Must be matched with bindSurfaceAsFBOForCopy.
+    void unbindSurfaceAsFBOForCopy(FBOBinding);
 
     GrGLContext fGLContext;
 
@@ -309,10 +326,9 @@ private:
         kUnknown_TriState
     };
 
-    GrGLuint                    fTempSrcFBOID;
-    GrGLuint                    fTempDstFBOID;
-
-    GrGLuint                    fStencilClearFBOID;
+    SkAutoTUnref<GrGLFBO> fTempSrcFBO;
+    SkAutoTUnref<GrGLFBO> fTempDstFBO;
+    SkAutoTUnref<GrGLFBO> fStencilClearFBO;
 
     // last scissor / viewport scissor state seen by the GL.
     struct {
@@ -458,9 +474,18 @@ private:
     GrPipelineBuilder::DrawFace fHWDrawFace;
     TriState                    fHWWriteToColor;
     TriState                    fHWDitherEnabled;
-    uint32_t                    fHWBoundRenderTargetUniqueID;
     SkTArray<uint32_t, true>    fHWBoundTextureUniqueIDs;
 
+    // Track fbo binding state.
+    struct HWFBOBinding {
+        uint32_t    fGenID;
+        bool        fIsDefaultFBO;
+        void invalidate() {
+            fGenID = SK_InvalidGenID;
+            fIsDefaultFBO = false;
+        }
+    } fHWFBOBinding[kFBOBindingCnt];

[egdaniel, 2015/02/25 16:21:34]

Do you want 3 of these? Is one for an invalidBinding?

+
     ///@}
 
     // we record what stencil format worked last time to hopefully exit early