gecko-dev/gfx/ipc/SharedDIBSurface.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "SharedDIBSurface.h"

#include "cairo.h"

namespace mozilla {
namespace gfx {

static const cairo_user_data_key_t SHAREDDIB_KEY = {0};

static const long kBytesPerPixel = 4;

bool
SharedDIBSurface::Create(HDC adc, uint32_t aWidth, uint32_t aHeight,
                         bool aTransparent)
{
  nsresult rv = mSharedDIB.Create(adc, aWidth, aHeight, aTransparent);
  if (NS_FAILED(rv) || !mSharedDIB.IsValid())
    return false;

  InitSurface(aWidth, aHeight, aTransparent);
  return true;
}

bool
SharedDIBSurface::Attach(Handle aHandle, uint32_t aWidth, uint32_t aHeight,
                         bool aTransparent)
{
  nsresult rv = mSharedDIB.Attach(aHandle, aWidth, aHeight, aTransparent);
  if (NS_FAILED(rv) || !mSharedDIB.IsValid())
    return false;

  InitSurface(aWidth, aHeight, aTransparent);
  return true;
}

void
SharedDIBSurface::InitSurface(uint32_t aWidth, uint32_t aHeight,
                              bool aTransparent)
{
  long stride = long(aWidth * kBytesPerPixel);
  unsigned char* data = reinterpret_cast<unsigned char*>(mSharedDIB.GetBits());

  gfxImageFormat format = aTransparent ? gfxImageFormat::ARGB32 : gfxImageFormat::RGB24;

  gfxImageSurface::InitWithData(data, IntSize(aWidth, aHeight),
                                stride, format);

  cairo_surface_set_user_data(mSurface, &SHAREDDIB_KEY, this, nullptr);
}

bool
SharedDIBSurface::IsSharedDIBSurface(gfxASurface* aSurface)
{
  return aSurface &&
    aSurface->GetType() == gfxSurfaceType::Image &&
    aSurface->GetData(&SHAREDDIB_KEY);
}

} // namespace gfx
} // namespace mozilla