gfx/ipc/SharedDIBWin.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "SharedDIBWin.h"
   7 #include "gfxAlphaRecovery.h"
   8 #include "nsMathUtils.h"
   9 #include "nsDebug.h"
  10
  11 namespace mozilla {
  12 namespace gfx {
  13
  14 static const uint32_t kBytesPerPixel = 4;
  15 static const uint32_t kByteAlign = 1 << gfxAlphaRecovery::GoodAlignmentLog2();
  16 static const uint32_t kHeaderBytes =
  17   (sizeof(BITMAPV4HEADER) + kByteAlign - 1) & ~(kByteAlign - 1);
  18
  19 SharedDIBWin::SharedDIBWin() :
  20     mSharedHdc(nullptr)
  21   , mSharedBmp(nullptr)
  22   , mOldObj(nullptr)
  23 {
  24 }
  25
  26 SharedDIBWin::~SharedDIBWin()
  27 {
  28   Close();
  29 }
  30
  31 nsresult
  32 SharedDIBWin::Close()
  33 {
  34   if (mSharedHdc && mOldObj)
  35     ::SelectObject(mSharedHdc, mOldObj);
  36
  37   if (mSharedHdc)
  38     ::DeleteObject(mSharedHdc);
  39
  40   if (mSharedBmp)
  41     ::DeleteObject(mSharedBmp);
  42
  43   mSharedHdc = NULL;
  44   mOldObj = mSharedBmp = NULL;
  45
  46   SharedDIB::Close();
  47
  48   return NS_OK;
  49 }
  50
  51 nsresult
  52 SharedDIBWin::Create(HDC aHdc, uint32_t aWidth, uint32_t aHeight,
  53                      bool aTransparent)
  54 {
  55   Close();
  56
  57   // create the offscreen shared dib
  58   BITMAPV4HEADER bmih;
  59   uint32_t size = SetupBitmapHeader(aWidth, aHeight, aTransparent, &bmih);
  60
  61   nsresult rv = SharedDIB::Create(size);
  62   if (NS_FAILED(rv))
  63     return rv;
  64
  65   if (NS_FAILED(SetupSurface(aHdc, &bmih))) {
  66     Close();
  67     return NS_ERROR_FAILURE;
  68   }
  69
  70   return NS_OK;
  71 }
  72
  73 nsresult
  74 SharedDIBWin::Attach(Handle aHandle, uint32_t aWidth, uint32_t aHeight,
  75                      bool aTransparent)
  76 {
  77   Close();
  78
  79   BITMAPV4HEADER bmih;
  80   SetupBitmapHeader(aWidth, aHeight, aTransparent, &bmih);
  81
  82   nsresult rv = SharedDIB::Attach(aHandle, 0);
  83   if (NS_FAILED(rv))
  84     return rv;
  85
  86   if (NS_FAILED(SetupSurface(NULL, &bmih))) {
  87     Close();
  88     return NS_ERROR_FAILURE;
  89   }
  90
  91   return NS_OK;
  92 }
  93
  94 uint32_t
  95 SharedDIBWin::SetupBitmapHeader(uint32_t aWidth, uint32_t aHeight,
  96                                 bool aTransparent, BITMAPV4HEADER *aHeader)
  97 {
  98   // D3D cannot handle an offscreen memory that pitch (SysMemPitch) is negative.
  99   // So we create top-to-bottom DIB.
 100   memset((void*)aHeader, 0, sizeof(BITMAPV4HEADER));
 101   aHeader->bV4Size          = sizeof(BITMAPV4HEADER);
 102   aHeader->bV4Width         = aWidth;
 103   aHeader->bV4Height        = -LONG(aHeight); // top-to-buttom DIB
 104   aHeader->bV4Planes        = 1;
 105   aHeader->bV4BitCount      = 32;
 106   aHeader->bV4V4Compression = BI_BITFIELDS;
 107   aHeader->bV4RedMask       = 0x00FF0000;
 108   aHeader->bV4GreenMask     = 0x0000FF00;
 109   aHeader->bV4BlueMask      = 0x000000FF;
 110
 111   if (aTransparent)
 112     aHeader->bV4AlphaMask     = 0xFF000000;
 113
 114   return (kHeaderBytes + (-aHeader->bV4Height * aHeader->bV4Width * kBytesPerPixel));
 115 }
 116
 117 nsresult
 118 SharedDIBWin::SetupSurface(HDC aHdc, BITMAPV4HEADER *aHdr)
 119 {
 120   mSharedHdc = ::CreateCompatibleDC(aHdc);
 121
 122   if (!mSharedHdc)
 123     return NS_ERROR_FAILURE;
 124
 125   mSharedBmp = ::CreateDIBSection(mSharedHdc,
 126                                   (BITMAPINFO*)aHdr,
 127                                   DIB_RGB_COLORS,
 128                                   &mBitmapBits,
 129                                   mShMem->handle(),
 130                                   kHeaderBytes);
 131   if (!mSharedBmp)
 132     return NS_ERROR_FAILURE;
 133
 134   mOldObj = SelectObject(mSharedHdc, mSharedBmp);
 135
 136   return NS_OK;
 137 }
 138
 139
 140 } // gfx
 141 } // mozilla