On some platforms SDL first sees the touch device if it was actually used.
Therefore the returned list might be empty, although devices are available.
After using all devices at least once the number will be correct.
a null-terminated array of touch device IDs or null on failure; call
SDL_GetError for more information. This should be freed with
SDL_free when it is no longer needed.
Get a list of registered touch devices.
On some platforms SDL first sees the touch device if it was actually used. Therefore the returned list might be empty, although devices are available. After using all devices at least once the number will be correct.