public BitmapRenderer(IntPtr dibHandle)
{
_dibHandle = dibHandle;
_bitmapPointer = Kernel32Native.GlobalLock(dibHandle);
_bitmapInfo = new BitmapInfoHeader();
Marshal.PtrToStructure(_bitmapPointer, _bitmapInfo);
_rectangle = new Rectangle();
_rectangle.X = _rectangle.Y = 0;
_rectangle.Width = _bitmapInfo.Width;
_rectangle.Height = _bitmapInfo.Height;
if (_bitmapInfo.SizeImage == 0)
{
_bitmapInfo.SizeImage = ((_bitmapInfo.Width * _bitmapInfo.BitCount + 31 & ~31) >> 3) * _bitmapInfo.Height;
}
// The following code only works on x86
Debug.Assert(Marshal.SizeOf(typeof(IntPtr)) == 4);
int pixelInfoPointer = _bitmapInfo.ClrUsed;
if (pixelInfoPointer == 0 && _bitmapInfo.BitCount <= 8)
{
pixelInfoPointer = 1 << (_bitmapInfo.BitCount); // & 31);
}
pixelInfoPointer = pixelInfoPointer * 4 + _bitmapInfo.Size + _bitmapPointer.ToInt32();
_pixelInfoPointer = new IntPtr(pixelInfoPointer);
}
protected virtual void Dispose(bool disposing)
{
Kernel32Native.GlobalUnlock(_dibHandle);
Kernel32Native.GlobalFree(_dibHandle);
}
