1 files changed, 114 insertions, 0 deletions
diff --git a/gfx/ipc/SharedDIBWin.cpp b/gfx/ipc/SharedDIBWin.cpp
new file mode 100644
index 0000000000..9669cb9491
--- /dev/null
+++ b/gfx/ipc/SharedDIBWin.cpp
@@ -0,0 +1,114 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 =
+    (uint32_t(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->GetHandle(), kHeaderBytes);
+  if (!mSharedBmp) return NS_ERROR_FAILURE;
+
+  mOldObj = SelectObject(mSharedHdc, mSharedBmp);
+
+  return NS_OK;
+}
+
+}  // namespace gfx
+}  // namespace mozilla