gecko-dev/gfx/thebes/gfxSharedImageSurface.cpp

96 lines
2.8 KiB
C++

// vim:set ts=4 sts=4 sw=4 et cin:
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* 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 "base/basictypes.h"
#include "gfxSharedImageSurface.h"
#include "cairo.h"
#define MOZ_ALIGN_WORD(x) (((x) + 3) & ~3)
using namespace mozilla::ipc;
static const cairo_user_data_key_t SHM_KEY = {0};
struct SharedImageInfo {
int32_t width;
int32_t height;
int32_t format;
};
static SharedImageInfo*
GetShmInfoPtr(const Shmem& aShmem)
{
return reinterpret_cast<SharedImageInfo*>
(aShmem.get<char>() + aShmem.Size<char>() - sizeof(SharedImageInfo));
}
gfxSharedImageSurface::~gfxSharedImageSurface()
{
MOZ_COUNT_DTOR(gfxSharedImageSurface);
}
/*static*/ bool
gfxSharedImageSurface::IsSharedImage(gfxASurface* aSurface)
{
return (aSurface
&& aSurface->GetType() == gfxASurface::SurfaceTypeImage
&& aSurface->GetData(&SHM_KEY));
}
gfxSharedImageSurface::gfxSharedImageSurface(const gfxIntSize& aSize,
gfxImageFormat aFormat,
const Shmem& aShmem)
{
MOZ_COUNT_CTOR(gfxSharedImageSurface);
mSize = aSize;
mFormat = aFormat;
mStride = ComputeStride(aSize, aFormat);
mShmem = aShmem;
mData = aShmem.get<unsigned char>();
cairo_surface_t *surface =
cairo_image_surface_create_for_data(mData,
(cairo_format_t)mFormat,
mSize.width,
mSize.height,
mStride);
if (surface) {
cairo_surface_set_user_data(surface, &SHM_KEY, this, NULL);
}
Init(surface);
}
void
gfxSharedImageSurface::WriteShmemInfo()
{
SharedImageInfo* shmInfo = GetShmInfoPtr(mShmem);
shmInfo->width = mSize.width;
shmInfo->height = mSize.height;
shmInfo->format = mFormat;
}
/*static*/ size_t
gfxSharedImageSurface::GetAlignedSize(const gfxIntSize& aSize, long aStride)
{
return MOZ_ALIGN_WORD(sizeof(SharedImageInfo) + aSize.height * aStride);
}
/*static*/ already_AddRefed<gfxSharedImageSurface>
gfxSharedImageSurface::Open(const Shmem& aShmem)
{
SharedImageInfo* shmInfo = GetShmInfoPtr(aShmem);
gfxIntSize size(shmInfo->width, shmInfo->height);
if (!CheckSurfaceSize(size))
return nullptr;
nsRefPtr<gfxSharedImageSurface> s =
new gfxSharedImageSurface(size,
(gfxImageFormat)shmInfo->format,
aShmem);
// We didn't create this Shmem and so don't free it on errors
return (s->CairoStatus() != 0) ? nullptr : s.forget();
}