view docs/man3/SDL_JoyBallEvent.3 @ 2328:91e601d9df8b

re: bug#563. checking in some commented out trace code and a fix so that the in testalpha.c the background only flashes when alpha == 255. The problem that is being fixed is caused by clearing SDL_COPY_RLE_COLORKEY without setting SDL_COPY_RLE_DESIRED in SDL_UnRELSurface.
author Bob Pendleton <bob@pendleton.com>
date Fri, 14 Mar 2008 18:17:49 +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