Mercurial > sdl-ios-xcode
view docs/man3/SDL_JoystickGetBall.3 @ 911:04a403e4ccf5
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_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