protected override void OnMouseUp(MouseEventArgs e)
{
Brightness = (float)(Height - e.Y) / Height;
Saturation = (float)e.X / Width;
if (Brightness < 0) Brightness = 0;
if (Brightness > 1) Brightness = 1;
if (Saturation < 0) Saturation = 0;
if (Saturation > 1) Saturation = 1;
_mouseDown = false;
}
protected override void OnPaint(PaintEventArgs e)