NAME¶
SDL_JoyBallEvent - Joystick trackball motion event structure
STRUCTURE DEFINITION¶
typedef struct{
Uint8 type;
Uint8 which;
Uint8 ball;
Sint16 xrel, yrel;
} SDL_JoyBallEvent;
STRUCTURE DATA¶
- type
- SDL_JOYBALLMOTION
- which
- Joystick device index
- ball
- Joystick trackball index
- xrel, yrel
- The relative motion in the X/Y direction
DESCRIPTION¶
SDL_JoyBallEvent is a member of the
SDL_Event union and is
used when an event of type
SDL_JOYBALLMOTION is reported.
A
SDL_JOYBALLMOTION event occurs when a user moves a trackball on the
joystick. The field
which is the index of the joystick that reported
the event and
ball is the index of the trackball (for a more detailed
explaination see the
Joystick section). Trackballs only return relative
motion, this is the change in position on the ball since it was last polled
(last cycle of the event loop) and it is stored in
xrel and
yrel.
SEE ALSO¶
SDL_Event,
Joystick Functions,
SDL_JoystickEventState ,
SDL_JoystickGetBall