SDL_JoystickGetBall

SDL Library

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SDL_JoystickGetBall

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!\n");
printf("Trackball Delta- X:%d, Y:%d\n", delta_x, delta_y);

See Also

SDL_JoystickNumBalls

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