Wiki Page Content

DRAFT

SDL_JoystickGetBall

Use this function to get the ball axis change since the last poll.

Syntax

int SDL_JoystickGetBall(SDL_Joystick* joystick,
                        int           ball,
                        int*          dx,
                        int*          dy)

Function Parameters

joystick

the SDL_Joystick to query

ball

the ball index to query; ball indices start at index 0

dx

the difference in the x axis position since the last poll

dy

the difference in the y axis position since the last poll

Return Value

Returns 0 on success or a negative error code on failure; call SDL_GetError() for more information.

Code 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);

Remarks

Trackballs can only return relative motion since the last call to SDL_JoystickGetBall(), these motion deltas are placed into dx and dy.


CategoryAPI, CategoryJoystick

None: SDL_JoystickGetBall (last edited 2015-05-31 19:12:46 by PhilippWiesemann)

(Page Info.)
Feedback
Please include your contact information if you'd like to receive a reply.
Submit