Mercurial > sdl-ios-xcode
view docs/man3/SDL_JoyBallEvent.3 @ 3191:91b335df6fc8
Fixed bug #750
Since many different event structures include windowID it should be placed near
the beginning of the structure (preferably right after type) so it's position
is the same between different events.
This is to avoid code like this:
if (event.type == SDL_WINDOWEVENT)
win = event.window.windowID;
else if ((SDL_EVENTMASK(event.type) & SDL_KEYEVENTMASK) != 0)
win = event.key.windowID;
else if (event.type == SDL_TEXTINPUT)
win = event.text.windowID;
else if (event.type == SDL_MOUSEMOTION)
win = event.motion.windowID;
else if ((SDL_EVENTMASK(event.type) & (SDL_MOUBUTTONDOWNMASK |
SDL_MOUBUTTONUPMASK)) != 0)
win = event.button.windowID;
else if (event.type == SDL_MOUSEWHEEL)
win = event.wheel.windowID;
...
in favor of:
win = event.window.windowID;
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Wed, 10 Jun 2009 14:00:21 +0000 |
| parents | 546f7c1eb755 |
| children | 1238da4a7112 |
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.TH "SDL_JoyBallEvent" "3" "Tue 11 Sep 2001, 22:59" "SDL" "SDL API Reference" .SH "NAME" SDL_JoyBallEvent \- Joystick trackball motion event structure .SH "STRUCTURE DEFINITION" .PP .nf \f(CWtypedef struct{ Uint8 type; Uint8 which; Uint8 ball; Sint16 xrel, yrel; } SDL_JoyBallEvent;\fR .fi .PP .SH "STRUCTURE DATA" .TP 20 \fBtype\fR \fBSDL_JOYBALLMOTION\fP .TP 20 \fBwhich\fR Joystick device index .TP 20 \fBball\fR Joystick trackball index .TP 20 \fBxrel\fR, \fByrel\fR The relative motion in the X/Y direction .SH "DESCRIPTION" .PP \fBSDL_JoyBallEvent\fR is a member of the \fI\fBSDL_Event\fR\fR union and is used when an event of type \fBSDL_JOYBALLMOTION\fP is reported\&. .PP A \fBSDL_JOYBALLMOTION\fP event occurs when a user moves a trackball on the joystick\&. The field \fBwhich\fR is the index of the joystick that reported the event and \fBball\fR is the index of the trackball (for a more detailed explaination see the \fIJoystick section\fR)\&. 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 \fBxrel\fR and \fByrel\fR\&. .SH "SEE ALSO" .PP \fI\fBSDL_Event\fR\fR, \fIJoystick Functions\fR, \fI\fBSDL_JoystickEventState\fP\fR, \fI\fBSDL_JoystickGetBall\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:59