Mercurial > sdl-ios-xcode
view docs/man3/SDL_CDStatus.3 @ 689:5bb080d35049
Date: Tue, 19 Aug 2003 17:57:00 +0200
From: Stephane Marchesin
Subject: Re: [SDL] [patch] MMX alpha blit patches with MMX detection
I think everything is correct now. I've done as much testing as I could,
but some real-world testing wouldn't hurt, I think.
The patch is here : http://icps.u-strasbg.fr/~marchesin/sdl_mmxblit.patch
If you do byte-by-byte comparison of the output between C and MMX
functions, you'll notice that the results for 555 and 565 RGB alpha
blits aren't exactly the same. This is because MMX functions for 555 and
565 RGB have an higher accuracy. If you want the exact same behaviour
that's possible by masking the three lower alpha bits in the MMX
functions. Just ask !
I removed one MMX function because after I fixed it to match its C
equivalent, it revealed to be slower than the C version on a PIII
(although a bit faster on an Athlon XP).
I've also added MMX and PIII replacements for SDL_memcpy. Those provide
some speed up in testvidinfo -benchmark (at least for me, under linux &
X11).
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 22 Aug 2003 05:51:19 +0000 (2003-08-22) |
parents | e5bc29de3f0a |
children | 546f7c1eb755 |
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.TH "SDL_CDStatus" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference" .SH "NAME" SDL_CDStatus\- Returns the current status of the given drive\&. .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBCDstatus \fBSDL_CDStatus\fP\fR(\fBSDL_CD *cdrom\fR); \fB/* Given a status, returns true if there\&'s a disk in the drive */ #define CD_INDRIVE(status) ((int)status > 0) .SH "DESCRIPTION" .PP This function returns the current status of the given drive\&. Status is described like so: .PP .nf \f(CWtypedef enum { CD_TRAYEMPTY, CD_STOPPED, CD_PLAYING, CD_PAUSED, CD_ERROR = -1 } CDstatus;\fR .fi .PP .PP If the drive has a CD in it, the table of contents of the CD and current play position of the CD will be stored in the SDL_CD structure\&. .PP The macro \fBCD_INDRIVE\fP is provided for convenience, and given a status returns true if there\&'s a disk in the drive\&. .PP .RS \fBNote: .PP \fBSDL_CDStatus\fP also updates the \fI\fBSDL_CD\fR\fR structure passed to it\&. .RE .SH "EXAMPLE" .PP .nf \f(CWint playTrack(int track) { int playing = 0; if ( CD_INDRIVE(SDL_CDStatus(cdrom)) ) { /* clamp to the actual number of tracks on the CD */ if (track >= cdrom->numtracks) { track = cdrom->numtracks-1; } if ( SDL_CDPlayTracks(cdrom, track, 0, 1, 0) == 0 ) { playing = 1; } } return playing; }\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_CD\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:58