This property controls whether the graph is drawn directly to the graphics device or using an off-screen image buffer. Set this property to false when the drawing speed of the graph seems very slow. When this property is set to false, it can increase the drawing speed by a factor of three in some situations.
boolean = getUseOffScreen();
Can be one of the following:
true draws directly to graphics device. This value is the default.
false uses off screen image buffer.