Add GrStencilBuffer as a separate resource type from render target

This is a resubmission of the changes in r2026 with fixes for FBO completeness issues.

Review URL: http://codereview.appspot.com/4837046/


git-svn-id: http://skia.googlecode.com/svn/trunk@2035 2bbb7eff-a529-9590-31e7-b0007b416f81

2 files changed, 28 insertions, 17 deletions

diff --git a/gpu/include/GrGpu.h b/gpu/include/GrGpu.h
index ef03bdbe3e..fff40fb147 100644
--- a/gpu/include/GrGpu.h
+++ b/gpu/include/GrGpu.h
@@ -19,6 +19,7 @@
 class GrContext;
 class GrIndexBufferAllocPool;
 class GrResource;
+class GrStencilBuffer;
 class GrVertexBufferAllocPool;
 
 /**
@@ -313,12 +314,13 @@ public:
 
     /**
      * Called to tell Gpu object that all GrResources have been lost and should
-     * be abandoned.
+     * be abandoned. Overrides must call INHERITED::abandonResources().
      */
     virtual void abandonResources();
 
     /**
-     * Called to tell Gpu object to release all GrResources.
+     * Called to tell Gpu object to release all GrResources. Overrides must call
+     * INHERITED::releaseResources().
      */
     void releaseResources();
 
@@ -469,6 +471,16 @@ protected:
                                int vertexCount,
                                int indexCount) = 0;
 
+    // width and height may be larger than rt (if underlying API allows it).
+    // Should attach the SB to the RT. Returns false if compatible sb could
+    // not be created.
+    virtual bool createStencilBufferForRenderTarget(GrRenderTarget* rt,
+                                                    int width, 
+                                                    int height) = 0;
+
+    // attaches an existing SB to an existing RT.
+    virtual bool attachStencilBufferToRenderTarget(GrStencilBuffer* sb,
+                                                   GrRenderTarget* rt) = 0;
 
     // The GrGpu typically records the clients requested state and then flushes
     // deltas from previous state at draw time. This function does the
@@ -513,6 +525,9 @@ private:
 
     GrResource*                 fResourceHead;
 
+    // Given a rt, find or create a stencil buffer and attach it
+    bool attachStencilBufferToRenderTarget(GrRenderTarget* target);
+
     // GrDrawTarget overrides
     virtual void onDrawIndexed(GrPrimitiveType type,
                                int startVertex,
diff --git a/gpu/include/GrRenderTarget.h b/gpu/include/GrRenderTarget.h
index a5616b9895..06d62a40be 100644
--- a/gpu/include/GrRenderTarget.h
+++ b/gpu/include/GrRenderTarget.h
@@ -18,10 +18,10 @@
 #ifndef GrRenderTarget_DEFINED
 #define GrRenderTarget_DEFINED
 
-#include "GrClip.h"
 #include "GrRect.h"
 #include "GrResource.h"
 
+class GrStencilBuffer;
 class GrTexture;
 
 /**
@@ -51,11 +51,6 @@ public:
     int config() const { return fConfig; }
 
     /**
-     * @return the number of stencil bits in the rendertarget
-     */
-    int stencilBits() const { return fStencilBits; }
-
-    /**
      * @return the texture associated with the rendertarget, may be NULL.
      */
     GrTexture* asTexture() {return fTexture;}
@@ -145,20 +140,25 @@ public:
     };
     virtual ResolveType getResolveType() const = 0;
 
+    /**
+     * GrStencilBuffer is not part of the public API.
+     */
+    GrStencilBuffer* getStencilBuffer() const { return fStencilBuffer; }
+    void setStencilBuffer(GrStencilBuffer* stencilBuffer);
+
 protected:
     GrRenderTarget(GrGpu* gpu,
                    GrTexture* texture,
                    int width,
                    int height,
                    GrPixelConfig config,
-                   int stencilBits,
                    int sampleCnt)
         : INHERITED(gpu)
+        , fStencilBuffer(NULL)
         , fTexture(texture)
         , fWidth(width)
         , fHeight(height)
         , fConfig(config)
-        , fStencilBits(stencilBits)
         , fSampleCnt(sampleCnt)
     {
         fResolveRect.setLargestInverted();
@@ -175,20 +175,16 @@ protected:
         fTexture = NULL;
     }
 
+    GrStencilBuffer*  fStencilBuffer;
+
 private:
-    GrTexture* fTexture; // not ref'ed
+    GrTexture*      fTexture; // not ref'ed
     int             fWidth;
     int             fHeight;
     GrPixelConfig   fConfig;
-    int             fStencilBits;
     int             fSampleCnt;
     GrIRect         fResolveRect;
 
-    // GrGpu keeps a cached clip in the render target to avoid redundantly
-    // rendering the clip into the same stencil buffer.
-    friend class GrGpu;
-    GrClip     fLastStencilClip;
-
     typedef GrResource INHERITED;
 };