Mercurial > sdl-ios-xcode
view docs/html/sdloverlay.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_Overlay</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="Video" HREF="video.html"><LINK REL="PREVIOUS" TITLE="SDL_VideoInfo" HREF="sdlvideoinfo.html"><LINK REL="NEXT" TITLE="Window Management" HREF="wm.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="sdlvideoinfo.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="wm.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLOVERLAY" ></A >SDL_Overlay</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN3464" ></A ><H2 >Name</H2 >SDL_Overlay -- YUV video overlay</DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3467" ></A ><H2 >Structure Definition</H2 ><PRE CLASS="PROGRAMLISTING" >typedef struct{ Uint32 format; int w, h; int planes; Uint16 *pitches; Uint8 **pixels; Uint32 hw_overlay:1; } SDL_Overlay;</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3470" ></A ><H2 >Structure Data</H2 ><DIV CLASS="INFORMALTABLE" ><A NAME="AEN3472" ></A ><P ></P ><TABLE BORDER="0" CLASS="CALSTABLE" ><TBODY ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >format</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Overlay format (see below)</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >w, h</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Width and height of overlay</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >planes</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Number of planes in the overlay. Usually either 1 or 3</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >pitches</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >An array of pitches, one for each plane. Pitch is the length of a row in bytes.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >pixels</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >An array of pointers to teh data of each plane. The overlay should be locked before these pointers are used.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >hw_overlay</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >This will be set to 1 if the overlay is hardware accelerated.</TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3499" ></A ><H2 >Description</H2 ><P >A <SPAN CLASS="STRUCTNAME" >SDL_Overlay</SPAN > is similar to a <A HREF="sdlsurface.html" ><SPAN CLASS="STRUCTNAME" >SDL_Surface</SPAN ></A > except it stores a YUV overlay. All the fields are read only, except for <TT CLASS="STRUCTFIELD" ><I >pixels</I ></TT > which should be <A HREF="sdllockyuvoverlay.html" >locked</A > before use. The <TT CLASS="STRUCTFIELD" ><I >format</I ></TT > field stores the format of the overlay which is one of the following: <PRE CLASS="PROGRAMLISTING" >#define SDL_YV12_OVERLAY 0x32315659 /* Planar mode: Y + V + U */ #define SDL_IYUV_OVERLAY 0x56555949 /* Planar mode: Y + U + V */ #define SDL_YUY2_OVERLAY 0x32595559 /* Packed mode: Y0+U0+Y1+V0 */ #define SDL_UYVY_OVERLAY 0x59565955 /* Packed mode: U0+Y0+V0+Y1 */ #define SDL_YVYU_OVERLAY 0x55595659 /* Packed mode: Y0+V0+Y1+U0 */</PRE > More information on YUV formats can be found at <A HREF="http://www.webartz.com/fourcc/indexyuv.htm" TARGET="_top" >http://www.webartz.com/fourcc/indexyuv.htm</A >.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3510" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlcreateyuvoverlay.html" ><TT CLASS="FUNCTION" >SDL_CreateYUVOverlay</TT ></A >, <A HREF="sdllockyuvoverlay.html" ><TT CLASS="FUNCTION" >SDL_LockYUVOverlay</TT ></A >, <A HREF="sdlunlockyuvoverlay.html" ><TT CLASS="FUNCTION" >SDL_UnlockYUVOverlay</TT ></A >, <A HREF="sdlfreeyuvoverlay.html" ><TT CLASS="FUNCTION" >SDL_FreeYUVOverlay</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="sdlvideoinfo.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="wm.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_VideoInfo</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="video.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Window Management</TD ></TR ></TABLE ></DIV ></BODY ></HTML >