Mercurial > sdl-ios-xcode
view docs/man3/SDL_JoystickGetBall.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_JoystickGetBall" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" .SH "NAME" SDL_JoystickGetBall \- Get relative trackball motion .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBint \fBSDL_JoystickGetBall\fP\fR(\fBSDL_Joystick *joystick, int ball, int *dx, int *dy\fR); .SH "DESCRIPTION" .PP Get the \fBball\fR axis change\&. .PP Trackballs can only return relative motion since the last call to \fBSDL_JoystickGetBall\fP, these motion deltas a placed into \fBdx\fR and \fBdy\fR\&. .SH "RETURN VALUE" .PP Returns \fB0\fR on success or \fB-1\fR on failure .SH "EXAMPLES" .PP .PP .nf \f(CWint delta_x, delta_y; SDL_Joystick *joy; \&. \&. \&. SDL_JoystickUpdate(); if(SDL_JoystickGetBall(joy, 0, &delta_x, &delta_y)==-1) printf("TrackBall Read Error! "); printf("Trackball Delta- X:%d, Y:%d ", delta_x, delta_y);\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_JoystickNumBalls\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00