Move DrawInfo out from GrDrawTarget and rename to GrVertices.

src/gpu/GrVertices.h

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrVertices_DEFINED
+#define GrVertices_DEFINED
+
+#include "GrIndexBuffer.h"
+#include "GrVertexBuffer.h"
+
+/**
+ * Used to communicate index and vertex buffers, counts, and offsets for a draw from GrBatch to
+ * GrGpu. It also holds the primitive type for the draw. TODO: Consider moving ownership of this
+ * and draw-issuing responsibility to GrPrimitiveProcessor. The rest of the vertex info lives there
+ * already (stride, attribute mappings).
+ */
+class GrVertices {
+public:
+    GrVertices() {}
+    GrVertices(const GrVertices& di) { (*this) = di; }
+    GrVertices& operator =(const GrVertices& 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 GrVertices. */
+    int verticesPerInstance() const { return fVerticesPerInstance; }
+    int indicesPerInstance() const { return fIndicesPerInstance; }
+    int instanceCount() const { return fInstanceCount; }
+
+    bool isIndexed() const { return fIndexCount > 0; }
+    bool isInstanced() const { return fInstanceCount > 0; }
+
+    /** 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 GrVertices 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(); }
+
+private:
+    GrPrimitiveType         fPrimitiveType;
+
+    int                     fStartVertex;
+    int                     fStartIndex;
+    int                     fVertexCount;
+    int                     fIndexCount;
+
+    int                     fInstanceCount;
+    int                     fVerticesPerInstance;
+    int                     fIndicesPerInstance;
+
+    GrPendingIOResource<const GrVertexBuffer, kRead_GrIOType> fVertexBuffer;
+    GrPendingIOResource<const GrIndexBuffer, kRead_GrIOType>  fIndexBuffer;
+};
+
+#endif