NAME¶
SDL_JoystickGetBall - Get relative trackball motion
SYNOPSIS¶
#include "SDL.h"
int SDL_JoystickGetBall(
SDL_Joystick *joystick, int
ball, int *dx, int *dy);
DESCRIPTION¶
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.
RETURN VALUE¶
Returns
0 on success or
-1 on failure
EXAMPLES¶
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);
SEE ALSO¶
SDL_JoystickNumBalls