Start on simplifying generateGeometry() overrides

src/gpu/GrDrawTarget.h

Index: src/gpu/GrDrawTarget.h
diff --git a/src/gpu/GrDrawTarget.h b/src/gpu/GrDrawTarget.h
index 0dca57a9db1be7131c679252108d9f2bbe1120e6..c58418139647e873acff77508cb0e092422dd93a 100644
--- a/src/gpu/GrDrawTarget.h
+++ b/src/gpu/GrDrawTarget.h
@@ -225,65 +225,132 @@ public:
     virtual DrawToken getCurrentDrawToken() { return DrawToken(this, 0); }
 
     /**
-     * Used to communicate draws to GPUs / subclasses
+     * Used to communicate draw index vertex offsets and counts toto GPUs / subclasses
      */
     class DrawInfo {
     public:
-        DrawInfo() { fDevBounds = NULL; }
+        DrawInfo() {}
         DrawInfo(const DrawInfo& di) { (*this) = di; }
         DrawInfo& operator =(const DrawInfo& di);
 
+        void init(GrPrimitiveType primType, const GrVertexBuffer* vertexBuffer, int startVertex,
+                  int vertexCount) {
+            SkASSERT(vertexBuffer);
+            SkASSERT(vertexCount);
+            SkASSERT(startVertex >= 0);
+            fPrimitiveType = primType;
+            fVertexBuffer.reset(SkRef(vertexBuffer));
+            fIndexBuffer.reset(NULL);
+            fStartVertex = startVertex;
+            fStartIndex = 0;
+            fVertexCount = vertexCount;
+            fIndexCount = 0;
+            fInstanceCount = 0;
+            fVerticesPerInstance = 0;
+            fIndicesPerInstance = 0;
+        }
+
+        void initIndexed(GrPrimitiveType primType,
+                         const GrVertexBuffer* vertexBuffer,
+                         const GrIndexBuffer* indexBuffer,
+                         int startVertex,
+                         int startIndex,
+                         int vertexCount,
+                         int indexCount) {
+            SkASSERT(indexBuffer);
+            SkASSERT(vertexBuffer);
+            SkASSERT(indexCount);
+            SkASSERT(vertexCount);
+            SkASSERT(startIndex >= 0);
+            SkASSERT(startVertex >= 0);
+            fPrimitiveType = primType;
+            fVertexBuffer.reset(SkRef(vertexBuffer));
+            fIndexBuffer.reset(SkRef(indexBuffer));
+            fStartVertex = startVertex;
+            fStartIndex = startIndex;
+            fVertexCount = vertexCount;
+            fIndexCount = indexCount;
+            fInstanceCount = 0;
+            fVerticesPerInstance = 0;
+            fIndicesPerInstance = 0;
+        }
+
+        void initInstanced(GrPrimitiveType primType,
+                           const GrVertexBuffer* vertexBuffer,
+                           const GrIndexBuffer* indexBuffer,
+                           int startVertex,
+                           int verticesPerInstance,
+                           int indicesPerInstance,
+                           int instanceCount) {
+            SkASSERT(vertexBuffer);
+            SkASSERT(indexBuffer);
+            SkASSERT(instanceCount);
+            SkASSERT(verticesPerInstance);
+            SkASSERT(indicesPerInstance);
+            SkASSERT(startVertex >= 0);
+            fPrimitiveType = primType;
+            fVertexBuffer.reset(SkRef(vertexBuffer));
+            fIndexBuffer.reset(SkRef(indexBuffer));
+            fStartVertex = startVertex;
+            fStartIndex = 0;
+            fVerticesPerInstance = verticesPerInstance;
+            fIndicesPerInstance = indicesPerInstance;
+            fInstanceCount = instanceCount;
+            fVertexCount = instanceCount * fVerticesPerInstance;
+            fIndexCount = instanceCount * fIndicesPerInstance;
+        }
+
+        /** Variation of the above that may be used when the total number of instances may exceed
+            the number of instances supported by the index buffer. To be used with
+            nextInstances() to draw in max-sized batches.*/
+        void initInstanced(GrPrimitiveType primType,
+                           const GrVertexBuffer* vertexBuffer,
+                           const GrIndexBuffer* indexBuffer,
+                           int startVertex,
+                           int verticesPerInstance,
+                           int indicesPerInstance,
+                           int* instancesRemaining,
+                           int maxInstancesPerDraw) {
+            int instanceCount = SkTMin(*instancesRemaining, maxInstancesPerDraw);
+            *instancesRemaining -= instanceCount;
+            this->initInstanced(primType, vertexBuffer, indexBuffer, startVertex,
+                                verticesPerInstance, indicesPerInstance, instanceCount);
+        }
+
         GrPrimitiveType primitiveType() const { return fPrimitiveType; }
         int startVertex() const { return fStartVertex; }
         int startIndex() const { return fStartIndex; }
         int vertexCount() const { return fVertexCount; }
         int indexCount() const { return fIndexCount; }
+
+        /** These return 0 if initInstanced was not used to initialize the DrawInfo. */
         int verticesPerInstance() const { return fVerticesPerInstance; }
         int indicesPerInstance() const { return fIndicesPerInstance; }
         int instanceCount() const { return fInstanceCount; }
 
-        void setPrimitiveType(GrPrimitiveType type) { fPrimitiveType = type; }
-        void setStartVertex(int startVertex) { fStartVertex = startVertex; }
-        void setStartIndex(int startIndex) { fStartIndex = startIndex; }
-        void setVertexCount(int vertexCount) { fVertexCount = vertexCount; }
-        void setIndexCount(int indexCount) { fIndexCount = indexCount; }
-        void setVerticesPerInstance(int verticesPerI) { fVerticesPerInstance = verticesPerI; }
-        void setIndicesPerInstance(int indicesPerI) { fIndicesPerInstance = indicesPerI; }
-        void setInstanceCount(int instanceCount) { fInstanceCount = instanceCount; }
-
         bool isIndexed() const { return fIndexCount > 0; }
-#ifdef SK_DEBUG
-        bool isInstanced() const; // this version is longer because of asserts
-#else
         bool isInstanced() const { return fInstanceCount > 0; }
-#endif
 
-        // adds or remove instances
-        void adjustInstanceCount(int instanceOffset);
-        // shifts the start vertex
-        void adjustStartVertex(int vertexOffset) {
-            fStartVertex += vertexOffset;
-            SkASSERT(fStartVertex >= 0);
-        }
-        // shifts the start index
-        void adjustStartIndex(int indexOffset) {
-            SkASSERT(this->isIndexed());
-            fStartIndex += indexOffset;
-            SkASSERT(fStartIndex >= 0);
-        }
-        void setDevBounds(const SkRect& bounds) {
-            fDevBoundsStorage = bounds;
-            fDevBounds = &fDevBoundsStorage;
+        /** Called after using this draw info to draw the next set of instances.
+            The vertex offset is advanced while the index buffer is reused at the same
+            position. instancesRemaining is number of instances that remain, maxInstances is
+            the most number of instances that can be used with the index buffer. If there
+            are no instances remaining, the DrawInfo is unmodified and false is returned.*/
+        bool nextInstances(int* instancesRemaining, int maxInstances) {
+            SkASSERT(this->isInstanced());
+            if (!*instancesRemaining) {
+                return false;
+            }
+            fStartVertex += fVertexCount;
+            fInstanceCount = SkTMin(*instancesRemaining, maxInstances);
+            fVertexCount = fInstanceCount * fVerticesPerInstance;
+            fIndexCount = fInstanceCount * fIndicesPerInstance;
+            *instancesRemaining -= fInstanceCount;
+            return true;
         }
+
         const GrVertexBuffer* vertexBuffer() const { return fVertexBuffer.get(); }
         const GrIndexBuffer* indexBuffer() const { return fIndexBuffer.get(); }
-        void setVertexBuffer(const GrVertexBuffer* vb) {
-            fVertexBuffer.reset(vb);
-        }
-        void setIndexBuffer(const GrIndexBuffer* ib) {
-            fIndexBuffer.reset(ib);
-        }
-        const SkRect* getDevBounds() const { return fDevBounds; }
 
     private:
         friend class GrDrawTarget;
@@ -299,9 +366,6 @@ public:
         int                     fVerticesPerInstance;
         int                     fIndicesPerInstance;
 
-        SkRect                  fDevBoundsStorage;
-        SkRect*                 fDevBounds;
-
         GrPendingIOResource<const GrVertexBuffer, kRead_GrIOType> fVertexBuffer;
         GrPendingIOResource<const GrIndexBuffer, kRead_GrIOType>  fIndexBuffer;
     };