Touch screens come in various technologies and capabilities and offer single touch, dual touch and multi-touch functionality.
Most operating systems offer single and multi-touch interfaces.
With single touch you can interface with the the OS as a 'mouse' type device or a 'touch' device. Standard touch drivers generally try to support the complete range of touches supported by the touch hardware, often via the native HID interface.
With UPDD you can configure the manner in which the driver posts touch data into the operating system. This can be useful in cases whereby only single touch is desired, even with multi-touch hardware. Further, some old legacy applications work OK with touchscreens running as 'mouse' devices but have issues with the HID touch interface. For example, an HID interface will generate a right click when the finger is held steady. Some applications may be using a steady touch for other purposes and do not want the touch to convert to a right click.
UPDD can be configured to support most desired modes of operation:
| OS |
Single touch mode |
Multi-touch mode |
| Windows |
Driver post data via mouse interface |
|
| |
Driver posts single touch to HID interface |
Driver posts all touch data to HID interface |
| Linux |
Driver post data via X interface |
|
| |
Driver posts single touch to uinput interface |
Driver posts all touch data to uinput interface |
| MacOS |
Driver post data via IOkit interface |
|
| |
Gestures process single touch only |
Gestures processes all touch data |