public GdiBitmap(int width, int height)
{
Width = width;
Height = height;
DeviceContext = Gdi32.CreateCompatibleDC(IntPtr.Zero);
var bitmapHeader = new BitmapInfoHeader
{
biSize = (uint)Marshal.SizeOf <BitmapInfoHeader>(),
biWidth = width,
biHeight = -height, // negative, top-down bitmap
biPlanes = 1,
biBitCount = (ushort)(8 * BytesPerPixel),
biCompression = BitmapCompression.BI_RGB,
};
var bitmapInfo = new BitmapInfo
{
bmiHeader = bitmapHeader,
};
BitmapHandle = Gdi32.CreateDIBSection(DeviceContext, in bitmapInfo, ColorUsage.DIB_RGB_COLORS,
out BitmapData, IntPtr.Zero, 0);
_oldObject = Gdi32.SelectObject(DeviceContext, BitmapHandle);
}
protected virtual void Dispose(bool disposing)
{
if (!_disposed)
{
if (disposing)
{
// TODO: dispose managed state (managed objects).
}
if (_oldObject != IntPtr.Zero)
{
Gdi32.SelectObject(DeviceContext, _oldObject);
}
if (BitmapHandle != IntPtr.Zero)
{
Gdi32.DeleteObject(BitmapHandle);
}
if (DeviceContext != IntPtr.Zero)
{
Gdi32.DeleteDC(DeviceContext);
}
_disposed = true;
}
}
private void UpdateWindow()
{
using var deviceContext = new GdiDeviceContext(_renderPanel.Handle);
Gdi32.StretchBlt(deviceContext, 0, 0, _renderPanel.Width, _renderPanel.Height,
_backBuffer.DeviceContext, 0, 0, BitmapWidth, BitmapHeight,
RasterOp.SRCCOPY);
}