gecko-dev/gfx/ipc/SharedDIBWin.cpp

140 lines
3.3 KiB
C++

/* -*- 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 "SharedDIBWin.h"
#include "gfxAlphaRecovery.h"
#include "nsMathUtils.h"
#include "nsDebug.h"
namespace mozilla {
namespace gfx {
static const uint32_t kByteAlign = 1 << gfxAlphaRecovery::GoodAlignmentLog2();
static const uint32_t kHeaderBytes =
(sizeof(BITMAPV4HEADER) + kByteAlign - 1) & ~(kByteAlign - 1);
SharedDIBWin::SharedDIBWin() :
mSharedHdc(nullptr)
, mSharedBmp(nullptr)
, mOldObj(nullptr)
{
}
SharedDIBWin::~SharedDIBWin()
{
Close();
}
nsresult
SharedDIBWin::Close()
{
if (mSharedHdc && mOldObj)
::SelectObject(mSharedHdc, mOldObj);
if (mSharedHdc)
::DeleteObject(mSharedHdc);
if (mSharedBmp)
::DeleteObject(mSharedBmp);
mSharedHdc = nullptr;
mOldObj = mSharedBmp = nullptr;
SharedDIB::Close();
return NS_OK;
}
nsresult
SharedDIBWin::Create(HDC aHdc, uint32_t aWidth, uint32_t aHeight,
bool aTransparent)
{
Close();
// create the offscreen shared dib
BITMAPV4HEADER bmih;
uint32_t size = SetupBitmapHeader(aWidth, aHeight, aTransparent, &bmih);
nsresult rv = SharedDIB::Create(size);
if (NS_FAILED(rv))
return rv;
if (NS_FAILED(SetupSurface(aHdc, &bmih))) {
Close();
return NS_ERROR_FAILURE;
}
return NS_OK;
}
nsresult
SharedDIBWin::Attach(Handle aHandle, uint32_t aWidth, uint32_t aHeight,
bool aTransparent)
{
Close();
BITMAPV4HEADER bmih;
SetupBitmapHeader(aWidth, aHeight, aTransparent, &bmih);
nsresult rv = SharedDIB::Attach(aHandle, 0);
if (NS_FAILED(rv))
return rv;
if (NS_FAILED(SetupSurface(nullptr, &bmih))) {
Close();
return NS_ERROR_FAILURE;
}
return NS_OK;
}
uint32_t
SharedDIBWin::SetupBitmapHeader(uint32_t aWidth, uint32_t aHeight,
bool aTransparent, BITMAPV4HEADER *aHeader)
{
// D3D cannot handle an offscreen memory that pitch (SysMemPitch) is negative.
// So we create top-to-bottom DIB.
memset((void*)aHeader, 0, sizeof(BITMAPV4HEADER));
aHeader->bV4Size = sizeof(BITMAPV4HEADER);
aHeader->bV4Width = aWidth;
aHeader->bV4Height = -LONG(aHeight); // top-to-buttom DIB
aHeader->bV4Planes = 1;
aHeader->bV4BitCount = 32;
aHeader->bV4V4Compression = BI_BITFIELDS;
aHeader->bV4RedMask = 0x00FF0000;
aHeader->bV4GreenMask = 0x0000FF00;
aHeader->bV4BlueMask = 0x000000FF;
if (aTransparent)
aHeader->bV4AlphaMask = 0xFF000000;
return (kHeaderBytes + (-aHeader->bV4Height * aHeader->bV4Width * kBytesPerPixel));
}
nsresult
SharedDIBWin::SetupSurface(HDC aHdc, BITMAPV4HEADER *aHdr)
{
mSharedHdc = ::CreateCompatibleDC(aHdc);
if (!mSharedHdc)
return NS_ERROR_FAILURE;
mSharedBmp = ::CreateDIBSection(mSharedHdc,
(BITMAPINFO*)aHdr,
DIB_RGB_COLORS,
&mBitmapBits,
mShMem->handle(),
kHeaderBytes);
if (!mSharedBmp)
return NS_ERROR_FAILURE;
mOldObj = SelectObject(mSharedHdc, mSharedBmp);
return NS_OK;
}
} // gfx
} // mozilla