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Date: Mon, 3 May 2004 03:15:01 +0100 From: David Symmonds Subject: SDL Typedef Structs Hi, Thanks for the SDL libraries, I have been using them for about a year now and they are really brilliant. One thing that I have just found whilst using them through C++ (and needing forward declarations) is that when you typedef structs you sometimes use typedef struct Name { ... }Name; e.g. SDL_Surface and other times use typedef struct { ... }Name; e.g. SDL_Rect The first type works fine, when I define a header file I can just put 'struct Name;' at the top and use the Name throughout. However, the second type is harder to use in a header, and I haven't found a way yet, other than to include 'SDL.h' in the header file (undesirable). Would there be any harm in changing the definition of SDL_Rect and such like to the second form?
author Sam Lantinga <slouken@libsdl.org>
date Sun, 18 Jul 2004 22:57:40 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.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