private static extern int DrawRectangleNative(int handle, ref ImageColor color, ref ImageRect rect);
private static extern int CropNative(int handle, ref ImageRect rect, out int croppedImageHandle);
private static extern int DrawRectangleNative(int handle, ref ImageColor color, ref ImageRect rect);
private static extern int CropNative(int handle, ref ImageRect rect, out int croppedImageHandle);