private Vector2 TransformPositionToViewport(Vector2 input)
{
var v2 = Options.TransformToViewport;
if (v2 == null)
{
return input;
}
var v1 = ProjectionStack.CurrentViewport;
float X, Y;
X = (input.X - v2.Value.X) * ((float)v1.Value.Width / v2.Value.Width);
Y = (input.Y - v2.Value.Y) * ((float)v1.Value.Height / v2.Value.Height);
return new Vector2(X, Y);
}