====== (This is the legacy documentation for stable SDL2, the current stable version; [https://wiki.libsdl.org/SDL3/ SDL3] is the current development version.) ======
= SDL_JoystickGetBall =
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'''
|stores the difference in the x axis position since the last poll
|-
|'''dy'''
|stores 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.
== Remarks ==
Trackballs can only return relative motion since the last call to
[[SDL_JoystickGetBall]](), these motion deltas are placed into
dx
and dy
.
Most joysticks do not have trackballs.
== Version ==
This function is available since SDL 2.0.0.
== Related Functions ==
:[[SDL_JoystickNumBalls]]
----
[[CategoryAPI]]