text: // Copyright 2013 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #ifndef UI_GFX_GPU_MEMORY_BUFFER_H_
  #define UI_GFX_GPU_MEMORY_BUFFER_H_
  
  #include <stddef.h>
  #include <stdint.h>
  
  #include "base/memory/shared_memory.h"
  #include "build/build_config.h"
  #include "ui/gfx/buffer_types.h"
  #include "ui/gfx/generic_shared_memory_id.h"
  #include "ui/gfx/geometry/rect.h"
  #include "ui/gfx/gfx_export.h"
  
  #if defined(USE_OZONE)
  #include "ui/gfx/native_pixmap_handle.h"
  #elif defined(OS_MACOSX) && !defined(OS_IOS)
  #include "ui/gfx/mac/io_surface.h"
  #endif
  
  extern "C" typedef struct _ClientBuffer* ClientBuffer;
  
  namespace gfx {
  
  class ColorSpace;
  
  enum GpuMemoryBufferType {
    EMPTY_BUFFER,
    SHARED_MEMORY_BUFFER,
    IO_SURFACE_BUFFER,
    OZONE_NATIVE_PIXMAP,
    GPU_MEMORY_BUFFER_TYPE_LAST = OZONE_NATIVE_PIXMAP
  };
  
  using GpuMemoryBufferId = GenericSharedMemoryId;
  
  struct GFX_EXPORT GpuMemoryBufferHandle {
    GpuMemoryBufferHandle();
    GpuMemoryBufferHandle(const GpuMemoryBufferHandle& other);
    ~GpuMemoryBufferHandle();
    bool is_null() const { return type == EMPTY_BUFFER; }
    GpuMemoryBufferType type;
    GpuMemoryBufferId id;
    base::SharedMemoryHandle handle;
    uint32_t offset;
    int32_t stride;
  #if defined(USE_OZONE)
    NativePixmapHandle native_pixmap_handle;
  #elif defined(OS_MACOSX) && !defined(OS_IOS)
    ScopedRefCountedIOSurfaceMachPort mach_port;
  #endif
  };
  
  // This interface typically correspond to a type of shared memory that is also
  // shared with the GPU. A GPU memory buffer can be written to directly by
  // regular CPU code, but can also be read by the GPU.
  class GFX_EXPORT GpuMemoryBuffer {
   public:
    virtual ~GpuMemoryBuffer() {}
  
    // Maps each plane of the buffer into the client's address space so it can be
    // written to by the CPU. This call may block, for instance if the GPU needs
    // to finish accessing the buffer or if CPU caches need to be synchronized.
    // Returns false on failure.
    virtual bool Map() = 0;
  
    // Returns a pointer to the memory address of a plane. Buffer must have been
    // successfully mapped using a call to Map() before calling this function.
    virtual void* memory(size_t plane) = 0;
  
    // Unmaps the buffer. It's illegal to use any pointer returned by memory()
    // after this has been called.
    virtual void Unmap() = 0;
  
    // Returns the size for the buffer.
    virtual Size GetSize() const = 0;
  
    // Returns the format for the buffer.
    virtual BufferFormat GetFormat() const = 0;
  
    // Fills the stride in bytes for each plane of the buffer. The stride of
    // plane K is stored at index K-1 of the |stride| array.
    virtual int stride(size_t plane) const = 0;
  
    // Set the color space in which this buffer should be interpreted when used
    // for scanout. Note that this will not impact texturing from the buffer.
    virtual void SetColorSpaceForScanout(const gfx::ColorSpace& color_space);
  
    // Returns a unique identifier associated with buffer.
    virtual GpuMemoryBufferId GetId() const = 0;
  
    // Returns a platform specific handle for this buffer.
    virtual GpuMemoryBufferHandle GetHandle() const = 0;
  
    // Type-checking downcast routine.
    virtual ClientBuffer AsClientBuffer() = 0;
  };
  
  // Returns an instance of |handle| which can be sent over IPC. This duplicates
  // the file-handles as appropriate, so that the IPC code take ownership of them,
  // without invalidating |handle| itself.
  GFX_EXPORT GpuMemoryBufferHandle
  CloneHandleForIPC(const GpuMemoryBufferHandle& handle);
  
  }  // namespace gfx
  
  #endif  // UI_GFX_GPU_MEMORY_BUFFER_H_
  