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Size: 1533
Comment: Updated usage of Color2 macro.
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Size: 1514
Comment: Removed *, BR and old formatting.
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| Deletions are marked like this. | Additions are marked like this. |
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| ||'''joystick'''||^the SDL_Joystick to query^|| | ||'''joystick'''||the SDL_Joystick to query|| |
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| *<<BR>>Trackballs can only return relative motion since the last call to [[SDL_JoystickGetBall]](), these motion deltas are placed into '''dx''' and '''dy'''. <<BR>>* | Trackballs can only return relative motion since the last call to [[SDL_JoystickGetBall]](), these motion deltas are placed into '''dx''' and '''dy'''. |
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| .[[SDL_JoystickNumBalls]] * | .[[SDL_JoystickNumBalls]] |
DRAFT |
SDL_JoystickGetBall
Use this function to get the ball axis change since the last poll.
Contents
Syntax
int SDL_JoystickGetBall(SDL_Joystick* joystick,
int ball,
int* dx,
int* dy)
Function Parameters
joystick |
the SDL_Joystick to query |
ball |
the ball indices index; starts 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 |
Is it possible to use more than one index for ball?
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.
