Mercurial > sdl-ios-xcode
view docs/html/sdlkeysym.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 |
line wrap: on
line source
<HTML ><HEAD ><TITLE >SDL_keysym</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="SDL Event Structures." HREF="eventstructures.html"><LINK REL="PREVIOUS" TITLE="SDL_QuitEvent" HREF="sdlquitevent.html"><LINK REL="NEXT" TITLE="SDLKey" HREF="sdlkey.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="sdlquitevent.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlkey.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLKEYSYM" ></A >SDL_keysym</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN4659" ></A ><H2 >Name</H2 >SDL_keysym -- Keysym structure</DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4662" ></A ><H2 >Structure Definition</H2 ><PRE CLASS="PROGRAMLISTING" >typedef struct{ Uint8 scancode; SDLKey sym; SDLMod mod; Uint16 unicode; } SDL_keysym;</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4665" ></A ><H2 >Structure Data</H2 ><DIV CLASS="INFORMALTABLE" ><A NAME="AEN4667" ></A ><P ></P ><TABLE BORDER="0" CLASS="CALSTABLE" ><TBODY ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >scancode</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Hardware specific scancode</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >sym</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >SDL virtual keysym</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >mod</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Current key modifiers</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >unicode</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Translated character</TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4686" ></A ><H2 >Description</H2 ><P >The <SPAN CLASS="STRUCTNAME" >SDL_keysym</SPAN > structure is used by reporting key presses and releases since it is a part of the <A HREF="sdlkeyboardevent.html" ><SPAN CLASS="STRUCTNAME" >SDL_KeyboardEvent</SPAN ></A >.</P ><P >The <TT CLASS="STRUCTFIELD" ><I >scancode</I ></TT > field should generally be left alone, it is the hardware dependent scancode returned by the keyboard. The <TT CLASS="STRUCTFIELD" ><I >sym</I ></TT > field is extremely useful. It is the SDL-defined value of the key (see <A HREF="sdlkey.html" >SDL Key Syms</A >. This field is very useful when you are checking for certain key presses, like so: <PRE CLASS="PROGRAMLISTING" >. . while(SDL_PollEvent(&event)){ switch(event.type){ case SDL_KEYDOWN: if(event.key.keysym.sym==SDLK_LEFT) move_left(); break; . . . } } . .</PRE > <TT CLASS="STRUCTFIELD" ><I >mod</I ></TT > stores the current state of the keyboard modifiers as explained in <A HREF="sdlgetmodstate.html" ><TT CLASS="FUNCTION" >SDL_GetModState</TT ></A >. The <TT CLASS="STRUCTFIELD" ><I >unicode</I ></TT > is only used when UNICODE translation is enabled with <A HREF="sdlenableunicode.html" ><TT CLASS="FUNCTION" >SDL_EnableUNICODE</TT ></A >. If <TT CLASS="STRUCTFIELD" ><I >unicode</I ></TT > is non-zero then this a the UNICODE character corresponding to the keypress. If the high 9 bits of the character are 0, then this maps to the equivalent ASCII character: <PRE CLASS="PROGRAMLISTING" >char ch; if ( (keysym.unicode & 0xFF80) == 0 ) { ch = keysym.unicode & 0x7F; } else { printf("An International Character.\n"); }</PRE > UNICODE translation does have a slight overhead so don't enable it unless its needed.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4705" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlkey.html" ><SPAN CLASS="STRUCTNAME" >SDLKey</SPAN ></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="sdlquitevent.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="sdlkey.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_QuitEvent</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="eventstructures.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDLKey</TD ></TR ></TABLE ></DIV ></BODY ></HTML >