Add SDL_TouchDeviceType enum and SDL_GetTouchDeviceType(SDL_TouchID id).

Touch device types include SDL_TOUCH_DEVICE_DIRECT (a touch screen with window-relative coordinates for touches), SDL_TOUCH_DEVICE_INDIRECT_ABSOLUTE (a trackpad-style device with absolute device coordinates), and SDL_TOUCH_DEVICE_INDIRECT_RELATIVE (a trackpad-style device with screen cursor-relative coordinates).

Phone screens are an example of a direct device type. Mac trackpads are the indirect-absolute touch device type. The Apple TV remote is an indirect-relative touch device type.
15 files changed