Get the number of registered touch devices.
Defined in SDL_touch.h
int SDL_GetNumTouchDevices(void);
(int) Returns the number of registered touch devices.
On some platforms SDL first sees the touch device if it was actually used. Therefore SDL_GetNumTouchDevices() may return 0 although devices are available. After using all devices at least once the number will be correct.
This was fixed for Android in SDL 2.0.1.
This function is available since SDL 2.0.0.