protected internal override void Begin(DrawState state)
{
DeviceContext device = state.Context;
state.ResetTextures();
device.SetRenderTarget(0, null);
Vector2 ws = new Vector2((float)Width, (float)Height);
if (ws.X != windowSize.X || ws.Y != windowSize.Y)
{
windowSize = ws;
windowSizeChangeIndex = System.Threading.Interlocked.Increment(ref DrawTarget.baseSizeIndex);
}
}