ui/gfx/native_pixmap_handle.h

// Copyright 2015 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_NATIVE_PIXMAP_HANDLE_H_
#define UI_GFX_NATIVE_PIXMAP_HANDLE_H_

#include <stddef.h>
#include <stdint.h>

#include <vector>

#include "build/build_config.h"
#include "ui/gfx/gfx_export.h"

#if defined(OS_LINUX)
#include "base/file_descriptor_posix.h"
#endif

namespace gfx {

// NativePixmapPlane is used to carry the plane related information for GBM
// buffer. More fields can be added if they are plane specific.
struct GFX_EXPORT NativePixmapPlane {
  // This is the same value as DRM_FORMAT_MOD_INVALID, which is not a valid
  // modifier. We use this to indicate that layout information
  // (tiling/compression) if any will be communicated out of band.
  static constexpr uint64_t kNoModifier = 0x00ffffffffffffffULL;

  NativePixmapPlane();
  NativePixmapPlane(int stride,
                    int offset,
                    uint64_t size,
                    uint64_t modifier = kNoModifier);
  NativePixmapPlane(const NativePixmapPlane& other);
  ~NativePixmapPlane();

  // The strides and offsets in bytes to be used when accessing the buffers via
  // a memory mapping. One per plane per entry.
  int stride;
  int offset;
  // Size in bytes of the plane.
  // This is necessary to map the buffers.
  uint64_t size;
  // The modifier is retrieved from GBM library and passed to EGL driver.
  // Generally it's platform specific, and we don't need to modify it in
  // Chromium code. Also one per plane per entry.
  uint64_t modifier;
};

struct GFX_EXPORT NativePixmapHandle {
  NativePixmapHandle();
  NativePixmapHandle(const NativePixmapHandle& other);

  ~NativePixmapHandle();

#if defined(OS_LINUX)
  // File descriptors for the underlying memory objects (usually dmabufs).
  std::vector<base::FileDescriptor> fds;
#endif
  std::vector<NativePixmapPlane> planes;
};

#if defined(OS_LINUX)
// Returns an instance of |handle| which can be sent over IPC. This duplicates
// the file-handles, so that the IPC code take ownership of them, without
// invalidating |handle|.
GFX_EXPORT NativePixmapHandle
CloneHandleForIPC(const NativePixmapHandle& handle);
#endif

}  // namespace gfx

#endif  // UI_GFX_NATIVE_PIXMAP_HANDLE_H_