/* * Copyright 2019 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #ifndef GrGpuBuffer_DEFINED #define GrGpuBuffer_DEFINED #include "include/gpu/GrGpuResource.h" #include "src/gpu/GrBuffer.h" class GrGpu; class GrGpuBuffer : public GrGpuResource, public GrBuffer { public: /** * Computes a scratch key for a GPU-side buffer with a "dynamic" access pattern. (Buffers with * "static" and "stream" patterns are disqualified by nature from being cached and reused.) */ static void ComputeScratchKeyForDynamicVBO(size_t size, GrGpuBufferType, GrScratchKey*); GrAccessPattern accessPattern() const { return fAccessPattern; } size_t size() const final { return fSizeInBytes; } void ref() const final { GrGpuResource::ref(); } void unref() const final { GrGpuResource::unref(); } /** * Maps the buffer to be read or written by the CPU. * * It is an error to draw from the buffer while it is mapped or transfer to/from the buffer. It * may fail if the backend doesn't support mapping the buffer. Once a buffer is mapped, * subsequent calls to map() trivially succeed. No matter how many times map() is called, * umap() will unmap the buffer on the first call if it is mapped. * * If the buffer is of type GrGpuBufferType::kXferGpuToCpu then it is mapped for reading only. * Otherwise it is mapped writing only. Writing to a buffer that is mapped for reading or vice * versa produces undefined results. If the buffer is mapped for writing then then the buffer's * previous contents are invalidated. * * @return a pointer to the data or nullptr if the map fails. */ void* map(); /** * Unmaps the buffer if it is mapped. * * The pointer returned by the previous map call will no longer be valid. */ void unmap(); /** * Queries whether the buffer has been mapped. * * @return true if the buffer is mapped, false otherwise. */ bool isMapped() const; bool isCpuBuffer() const final { return false; } /** * Updates the buffer data. * * The size of the buffer will be preserved. The src data will be * placed at the beginning of the buffer and any remaining contents will * be undefined. srcSizeInBytes must be <= to the buffer size. * * The buffer must not be mapped. * * Fails for GrGpuBufferType::kXferGpuToCpu. * * Note that buffer updates do not go through GrContext and therefore are * not serialized with other operations. * * @return returns true if the update succeeds, false otherwise. */ bool updateData(const void* src, size_t srcSizeInBytes); protected: GrGpuBuffer(GrGpu*, size_t sizeInBytes, GrGpuBufferType, GrAccessPattern); GrGpuBufferType intendedType() const { return fIntendedType; } void* fMapPtr; private: virtual void onMap() = 0; virtual void onUnmap() = 0; virtual bool onUpdateData(const void* src, size_t srcSizeInBytes) = 0; size_t onGpuMemorySize() const override { return fSizeInBytes; } const char* getResourceType() const override { return "Buffer Object"; } void computeScratchKey(GrScratchKey* key) const override; size_t fSizeInBytes; GrAccessPattern fAccessPattern; GrGpuBufferType fIntendedType; }; #endif