SDL_JoystickGetBall — Get relative trackball motion
#include "SDL.h"
int
SDL_JoystickGetBall( |
SDL_Joystick * | joystick, |
| int | ball, | |
| int * | dx, | |
| int * | dy); |
Get the ball axis
change.
Trackballs can only return relative motion since the last
call to SDL_JoystickGetBall,
these motion deltas a placed into dx and dy.
int delta_x, delta_y;
SDL_Joystick *joy;
.
.
.
SDL_JoystickUpdate();
if(SDL_JoystickGetBall(joy, 0, &delta_x, &delta_y)==-1)
printf("TrackBall Read Error!
");
printf("Trackball Delta- X:%d, Y:%d
", delta_x, delta_y);