CSS_CIRCULARVALUE
Direct manipulation is performed by using a mouse to click on and drag the circular slider. There are two modes of direct manipulation for the circular slider.
The default direct manipulation mode is to scroll to the value indicated by the position of the mouse. This could be important if you used a circular slider for a volume control, for example. Increasing the volume from 0% to 100% too quickly could result in damage to both the user's ears and the equipment.
The other mode of direct manipulation permits the value on the circular slider to change immediately when dragged. This mode is enabled using the CSS_POINTSELECT style bit. When this style is used, the value of the dial can be changed by tracking the value with the mouse, which changes values quickly.
CSS_360 forces the CSS_NONUMBER style on. This is necessary to keep the value indicator from corrupting the number value.