Mercurial > sdl-ios-xcode

view docs/html/cdrom.html @ 1259:36f24cdfcda7

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
te: Thu, 17 Apr 2003 11:25:26 -0700 From: "Jim" Subject: [SDL] Frame buffer patches... Would seem that GCC 3.2.2 promotes all signed values to unsigned if any single vlaue is unsigned in an expression... for instance when calculating an elo touch position....evertyhign is an (int) except for cach_vinfo.xres which is unsigned. THerefore if y ou reverse the SDL_ELO_MIN_X and SDL_ELO_MAX_X values the resulging negative value pegs the expression to it's max. Attached it the accumu lated patch to typecast the unsigned values to (int) - *dx = (cache_vinfo.xres - (cache_vinfo.xres * (input_x - ELO_MIN_X)) / width); + *dx = ((int)cache_vinfo.xres - ((int)cache_vinfo.xres * (input_x - ELO_MIN_X)) / width); and also to provide quite failure to operations which have the screen currently locked... The touch screen I'm using the original values were exactly opposite of any position I touched on the screen - evaluating the math the expr ession SHOULD have handled reversing the min and max values - and after casting the unsigned .xres and .yres to a signed int - worked well. .. Jim
author Sam Lantinga <slouken@libsdl.org>
date Tue, 24 Jan 2006 06:36:43 +0000
parents 355632dca928
children
line wrap: on
line source

<HTML
><HEAD
><TITLE
>CD-ROM</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 Reference"
HREF="reference.html"><LINK
REL="PREVIOUS"
TITLE="SDL_CloseAudio"
HREF="sdlcloseaudio.html"><LINK
REL="NEXT"
TITLE="SDL_CDNumDrives"
HREF="sdlcdnumdrives.html"><META
NAME="KEYWORD"
CONTENT="cdrom"><META
NAME="KEYWORD"
CONTENT="function"></HEAD
><BODY
CLASS="CHAPTER"
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="sdlcloseaudio.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="sdlcdnumdrives.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="CHAPTER"
><H1
><A
NAME="CDROM"
></A
>Chapter 11. CD-ROM</H1
><DIV
CLASS="TOC"
><DL
><DT
><B
>Table of Contents</B
></DT
><DT
><A
HREF="sdlcdnumdrives.html"
>SDL_CDNumDrives</A
>&nbsp;--&nbsp;Returns the number of CD-ROM drives on the system.</DT
><DT
><A
HREF="sdlcdname.html"
>SDL_CDName</A
>&nbsp;--&nbsp;Returns a human-readable, system-dependent identifier for the CD-ROM.</DT
><DT
><A
HREF="sdlcdopen.html"
>SDL_CDOpen</A
>&nbsp;--&nbsp;Opens a CD-ROM drive for access.</DT
><DT
><A
HREF="sdlcdstatus.html"
>SDL_CDStatus</A
>&nbsp;--&nbsp;Returns the current status of the given drive.</DT
><DT
><A
HREF="sdlcdplay.html"
>SDL_CDPlay</A
>&nbsp;--&nbsp;Play a CD</DT
><DT
><A
HREF="sdlcdplaytracks.html"
>SDL_CDPlayTracks</A
>&nbsp;--&nbsp;Play the given CD track(s)</DT
><DT
><A
HREF="sdlcdpause.html"
>SDL_CDPause</A
>&nbsp;--&nbsp;Pauses a CDROM</DT
><DT
><A
HREF="sdlcdresume.html"
>SDL_CDResume</A
>&nbsp;--&nbsp;Resumes a CDROM</DT
><DT
><A
HREF="sdlcdstop.html"
>SDL_CDStop</A
>&nbsp;--&nbsp;Stops a CDROM</DT
><DT
><A
HREF="sdlcdeject.html"
>SDL_CDEject</A
>&nbsp;--&nbsp;Ejects a CDROM</DT
><DT
><A
HREF="sdlcdclose.html"
>SDL_CDClose</A
>&nbsp;--&nbsp;Closes a SDL_CD handle</DT
><DT
><A
HREF="sdlcd.html"
>SDL_CD</A
>&nbsp;--&nbsp;CDROM Drive Information</DT
><DT
><A
HREF="sdlcdtrack.html"
>SDL_CDtrack</A
>&nbsp;--&nbsp;CD Track Information Structure</DT
></DL
></DIV
><P
>SDL supports audio control of up to 32 local CD-ROM drives at once.</P
><P
>You use this API to perform all the basic functions of a CD player,
including listing the tracks, playing, stopping, and ejecting the CD-ROM.
(Currently, multi-changer CD drives are not supported.)</P
><P
>Before you call any of the SDL CD-ROM functions, you must first call
"<TT
CLASS="FUNCTION"
>SDL_Init(SDL_INIT_CDROM)</TT
>", which scans the system for
CD-ROM drives, and sets the program up for audio control.  Check the 
return code, which should be <SPAN
CLASS="RETURNVALUE"
>0</SPAN
>, to see if there 
were any errors in starting up.</P
><P
>After you have initialized the library, you can find out how many drives
are available using the <TT
CLASS="FUNCTION"
>SDL_CDNumDrives()</TT
> function.  
The first drive listed is the system default CD-ROM drive.  After you have 
chosen a drive, and have opened it with <TT
CLASS="FUNCTION"
>SDL_CDOpen()</TT
>, 
you can check the status and start playing if there's a CD in the drive.</P
><P
>A CD-ROM is organized into one or more tracks, each consisting of a certain
number of "frames".  Each frame is ~2K in size, and at normal playing speed,
a CD plays 75 frames per second.  SDL works with the number of frames on a
CD, but this can easily be converted to the more familiar minutes/seconds
format by using the <TT
CLASS="FUNCTION"
>FRAMES_TO_MSF()</TT
> macro.</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="sdlcloseaudio.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="sdlcdnumdrives.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>SDL_CloseAudio</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="reference.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>SDL_CDNumDrives</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>