3 * Copyright 2011 Google Inc.
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
10 #ifndef GrGeometryBuffer_DEFINED
11 #define GrGeometryBuffer_DEFINED
13 #include "GrGpuResource.h"
18 * Parent class for vertex and index buffers
20 class GrGeometryBuffer : public GrGpuResource {
22 SK_DECLARE_INST_COUNT(GrGeometryBuffer);
25 *Retrieves whether the buffer was created with the dynamic flag
27 * @return true if the buffer was created with the dynamic flag
29 bool dynamic() const { return fDynamic; }
32 * Returns true if the buffer is a wrapper around a CPU array. If true it
33 * indicates that map will always succeed and will be free.
35 bool isCPUBacked() const { return fCPUBacked; }
38 * Maps the buffer to be written by the CPU.
40 * The previous content of the buffer is invalidated. It is an error
41 * to draw from the buffer while it is mapped. It is an error to call map
42 * on an already mapped buffer. It may fail if the backend doesn't support
43 * mapping the buffer. If the buffer is CPU backed then it will always
44 * succeed and is a free operation. Must be matched by an unmap() call.
45 * Currently only one map at a time is supported (no nesting of
48 * Note that buffer mapping does not go through GrContext and therefore is
49 * not serialized with other operations.
51 * @return a pointer to the data or NULL if the map fails.
53 void* map() { return (fMapPtr = this->onMap()); }
58 * The pointer returned by the previous map call will no longer be valid.
61 SkASSERT(NULL != fMapPtr);
67 * Returns the same ptr that map() returned at time of map or NULL if the
70 * @return ptr to mapped buffer data or NULL if buffer is not mapped.
72 void* mapPtr() const { return fMapPtr; }
75 Queries whether the buffer has been mapped.
77 @return true if the buffer is mapped, false otherwise.
79 bool isMapped() const { return NULL != fMapPtr; }
82 * Updates the buffer data.
84 * The size of the buffer will be preserved. The src data will be
85 * placed at the beginning of the buffer and any remaining contents will
86 * be undefined. srcSizeInBytes must be <= to the buffer size.
88 * The buffer must not be mapped.
90 * Note that buffer updates do not go through GrContext and therefore are
91 * not serialized with other operations.
93 * @return returns true if the update succeeds, false otherwise.
95 bool updateData(const void* src, size_t srcSizeInBytes) {
96 SkASSERT(!this->isMapped());
97 SkASSERT(srcSizeInBytes <= fGpuMemorySize);
98 return this->onUpdateData(src, srcSizeInBytes);
101 // GrGpuResource overrides
102 virtual size_t gpuMemorySize() const { return fGpuMemorySize; }
105 GrGeometryBuffer(GrGpu* gpu, bool isWrapped, size_t gpuMemorySize, bool dynamic, bool cpuBacked)
106 : INHERITED(gpu, isWrapped)
108 , fGpuMemorySize(gpuMemorySize)
110 , fCPUBacked(cpuBacked) {}
113 virtual void* onMap() = 0;
114 virtual void onUnmap() = 0;
115 virtual bool onUpdateData(const void* src, size_t srcSizeInBytes) = 0;
118 size_t fGpuMemorySize;
122 typedef GrGpuResource INHERITED;