For VAOs, track and deduplicate redundant chunks

* This is really a spot optimisation but I have a feeling it might be
  useful for more programs.
* If a program uses a single VAO and updates the attrib pointers/enables
  and disables them, then this will prevent an unbounded number of chunks
  building up pointlessly while READING and pushing into the record.
* A 'better' fix for this would be to gather pointer/enabled state as
  initial contents and not tracking any of this except for in CAPFRAME,
  but that isn't happening at the moment.

renderdoc/core/resource_manager.h

@@ -139,6 +139,20 @@ struct ResourceRecord
 
 	ResourceId GetResourceID() const { return ResID; }
 
+	void RemoveChunk(Chunk *chunk)
+	{
+		LockChunks();
+		for(auto it=m_Chunks.begin(); it != m_Chunks.end(); ++it)
+		{
+			if(it->second == chunk)
+			{
+				m_Chunks.erase(it);
+				break;
+			}
+		}
+		UnlockChunks();
+	}
+
 	void AddChunk(Chunk *chunk, int32_t ID = 0)
 	{
 		LockChunks();

renderdoc/driver/gl/gl_resources.h

@@ -101,6 +101,8 @@ struct GLResourceRecord : public ResourceRecord
 		usage(eGL_UNKNOWN_ENUM)
 	{
 		RDCEraseEl(ShadowPtr);
+		RDCEraseEl(ptrchunks);
+		RDCEraseEl(enabledchunks);
 	}
 
 	~GLResourceRecord()
@@ -154,6 +156,9 @@ struct GLResourceRecord : public ResourceRecord
 	{
 		return ShadowPtr[p];
 	}
+
+	Chunk *ptrchunks[12];
+	Chunk *enabledchunks[12];
 	
 private:
 	byte *ShadowPtr[2];

renderdoc/driver/gl/wrappers/gl_buffer_funcs.cpp

@@ -1120,9 +1120,16 @@ void WrappedOpenGL::glVertexAttribPointer(GLuint index, GLint size, GLenum type,
 		Serialise_glVertexAttribPointer(index, size, type, normalized, stride, pointer);
 
 		if(m_State == WRITING_CAPFRAME)
+		{
 			m_ContextRecord->AddChunk(scope.Get());
+		}
 		else
-			r->AddChunk(scope.Get());
+		{
+			r->RemoveChunk(r->ptrchunks[index]);
+			delete r->ptrchunks[index];
+			Chunk *newchunk = r->ptrchunks[index] = scope.Get();
+			r->AddChunk(newchunk);
+		}
 	}
 }
 
@@ -1166,9 +1173,16 @@ void WrappedOpenGL::glVertexAttribIPointer(GLuint index, GLint size, GLenum type
 		Serialise_glVertexAttribIPointer(index, size, type, stride, pointer);
 
 		if(m_State == WRITING_CAPFRAME)
+		{
 			m_ContextRecord->AddChunk(scope.Get());
+		}
 		else
-			r->AddChunk(scope.Get());
+		{
+			r->RemoveChunk(r->ptrchunks[index]);
+			delete r->ptrchunks[index];
+			Chunk *newchunk = r->ptrchunks[index] = scope.Get();
+			r->AddChunk(newchunk);
+		}
 	}
 }
 
@@ -1207,9 +1221,16 @@ void WrappedOpenGL::glEnableVertexAttribArray(GLuint index)
 		Serialise_glEnableVertexAttribArray(index);
 
 		if(m_State == WRITING_CAPFRAME)
+		{
 			m_ContextRecord->AddChunk(scope.Get());
+		}
 		else
-			r->AddChunk(scope.Get());
+		{
+			r->RemoveChunk(r->enabledchunks[index]);
+			delete r->enabledchunks[index];
+			Chunk *newchunk = r->enabledchunks[index] = scope.Get();
+			r->AddChunk(newchunk);
+		}
 	}
 }
 
@@ -1247,9 +1268,16 @@ void WrappedOpenGL::glDisableVertexAttribArray(GLuint index)
 		Serialise_glDisableVertexAttribArray(index);
 
 		if(m_State == WRITING_CAPFRAME)
+		{
 			m_ContextRecord->AddChunk(scope.Get());
+		}
 		else
-			r->AddChunk(scope.Get());
+		{
+			r->RemoveChunk(r->enabledchunks[index]);
+			delete r->enabledchunks[index];
+			Chunk *newchunk = r->enabledchunks[index] = scope.Get();
+			r->AddChunk(newchunk);
+		}
 	}
 }