Mercurial > sdl-ios-xcode
view docs/html/sdlwasinit.html @ 1157:baf35853ad54
Date: Mon, 10 Oct 2005 13:09:32 +0300
From: Tommi Kyntola <tommi.kyntola@ray.fi>
To: sdl@libsdl.org
Subject: [SDL] [RFC] get_ticks broken on linux
It uses gettimeofday to calculate the timedifference.
Gettimeofday returns current time which is seldom monotonous.
This breaks SDL timer subsystem. (time callbacks and all that
get borked when the time difference ms is suddenly ~ 2^32)
I posted a message about this earlier but got no response.
Some thoughts on this matter would be appreciated.
(Or even an explanation for the lack of interest.)
A patch below would use the posix timers that have been around
since posix 93 and do provide a good source of monotonous time
on linux boxes (and on few others too).
The following patch is also availabe at:
http://www.hut.fi/u/tkyntola/SDL-1.2.9-clockfix.patch
It's against 1.2.9, but I can easily rediffit against
the cvs branch is needed.
cheers,
Tommi Kyntola tommi.kyntola@ray.fi
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Tue, 11 Oct 2005 18:16:12 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_WasInit</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="General" HREF="general.html"><LINK REL="PREVIOUS" TITLE="SDL_Quit" HREF="sdlquit.html"><LINK REL="NEXT" TITLE="SDL_GetError" HREF="sdlgeterror.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdlquit.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlgeterror.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLWASINIT" ></A >SDL_WasInit</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN617" ></A ><H2 >Name</H2 >SDL_WasInit -- Check which subsystems are initialized</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN620" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN621" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >Uint32 <B CLASS="FSFUNC" >SDL_WasInit</B ></CODE >(Uint32 flags);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN627" ></A ><H2 >Description</H2 ><P ><TT CLASS="FUNCTION" >SDL_WasInit</TT > allows you to see which SDL subsytems have been <A HREF="sdlinit.html" >initialized</A >. <TT CLASS="PARAMETER" ><I >flags</I ></TT > is a bitwise OR'd combination of the subsystems you wish to check (see <A HREF="sdlinit.html" ><TT CLASS="FUNCTION" >SDL_Init</TT ></A > for a list of subsystem flags).</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN635" ></A ><H2 >Return Value</H2 ><P ><TT CLASS="FUNCTION" >SDL_WasInit</TT > returns a bitwised OR'd combination of the initialized subsystems.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN639" ></A ><H2 >Examples</H2 ><PRE CLASS="PROGRAMLISTING" > /* Here are several ways you can use SDL_WasInit() */ /* Get init data on all the subsystems */ Uint32 subsystem_init; subsystem_init=SDL_WasInit(SDL_INIT_EVERYTHING); if(subsystem_init&SDL_INIT_VIDEO) printf("Video is initialized.\n"); else printf("Video is not initialized.\n"); /* Just check for one specfic subsystem */ if(SDL_WasInit(SDL_INIT_VIDEO)!=0) printf("Video is initialized.\n"); else printf("Video is not initialized.\n"); /* Check for two subsystems */ Uint32 subsystem_mask=SDL_INIT_VIDEO|SDL_INIT_AUDIO; if(SDL_WasInit(subsystem_mask)==subsystem_mask) printf("Video and Audio initialized.\n"); else printf("Video and Audio not initialized.\n"); </PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN642" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlinit.html" ><TT CLASS="FUNCTION" >SDL_Init</TT ></A >, <A HREF="sdlinitsubsystem.html" ><TT CLASS="FUNCTION" >SDL_Subsystem</TT ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlquit.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlgeterror.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_Quit</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="general.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_GetError</TD ></TR ></TABLE ></DIV ></BODY ></HTML >