Digitizer Driver Technology

Describes how screen coordinates work with the Digitizer Driver.

The digitizer hardware provides coordinate values that are digitized raw voltage values. These values are not the same as screen coordinates, which are based on pixel positions. The digitizer converts the raw values into screen coordinates and vice-versa.

Screen coordinates always have their origin at the top left hand corner of the screen, but the digitizer has no such constraint - its origin, orientation and scaling are generally different from the screen coordinate system. This means that the digitizer needs to be calibrated so that digitizer coordinates can be translated to screen coordinates.