Implement texel buffers

src/gpu/gl/GrGLBuffer.h

Index: src/gpu/gl/GrGLBuffer.h
diff --git a/src/gpu/gl/GrGLBuffer.h b/src/gpu/gl/GrGLBuffer.h
index b3b4feb00273bbc33733d58265e79f382cd46ec9..84d05be382b74e1641e0e4c5da231362c3a56880 100644
--- a/src/gpu/gl/GrGLBuffer.h
+++ b/src/gpu/gl/GrGLBuffer.h
@@ -27,6 +27,15 @@ public:
     GrGLuint bufferID() const { return fBufferID; }
     size_t baseOffset() const { return reinterpret_cast<size_t>(fCPUData); }
 
+    /**
+     * Returns the actual size of the underlying GL buffer object. In certain cases we may make this
+     * smaller than the size reported by GrBuffer.
+     */
+    size_t glSizeInBytes() const { return fGLSizeInBytes; }
+
+    void setHasAttachedToTexture() { fHasAttachedToTexture = true; }

[bsalomon, 2016/04/11 16:51:38]

Maybe (set)isAttachedToTexture? More clear that is is now not just has been at
some point.

[Chris Dalton, 2016/04/11 19:48:19]

Actually the intention of this bool is to know if it has *ever* been attached to
a
texture. Then upon deletion, it only tries to detach it from any possible buffer
textures if it has been attached at some point in the past.

We could instead be more elaborate and complex, and maintain a count of how many
buffer
textures it is attached to. Do you prefer one way or the other? I don't have a
preference myself.

[bsalomon, 2016/04/11 20:37:11]

Got it. I'm ok with it as is.

+    bool hasAttachedToTexture() const { return fHasAttachedToTexture; }
+
 protected:
     GrGLBuffer(GrGLGpu*, size_t size, GrBufferType intendedType, GrAccessPattern, bool cpuBacked,
                const void* data);
@@ -53,8 +62,8 @@ private:
     GrGLuint       fBufferID;
     size_t         fSizeInBytes;
     GrGLenum       fUsage;
-    size_t         fGLSizeInBytes;     // In certain cases we make the size of the GL buffer object
-                                       // smaller or larger than the size in fDesc.
+    size_t         fGLSizeInBytes;
+    bool           fHasAttachedToTexture;
 
     typedef GrBuffer INHERITED;
 };