From: Shawn Hargreaves <Shawn AT talula DOT demon DOT co DOT uk>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: FIX math in Allegro misfeature (possible) ?
Date: Mon, 3 Feb 1997 20:04:08 +0000
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Dim Zegebart writes:
>I just try to use fix math in Allegro. And I'm supprasing why where are
>no macros or functions like this (may be I missed something ?) :
>
>#define GET_INT(fFix)  (int)(((fFix)>>16)&0x0000ffff)

This is the same as the fixtoi() function.

>#define GET_FIX(fFix) (int)((fFix)&0x0000ffff)
>#define SET_FIX(fFix,nFix) fFix=((fFix)&0xffff0000)|((nFix)&0x0000ffff)
>#define SET_INT(fFix,nInt)
>fFix=((fFix)&0x0000ffff)|(((nInt)<<16)&0xffff0000)

I don't really see why these would be needed. Allegro has functions to
convert fixed point values to/from floats and ints - why do you need to
access the integer and fractional parts individually? It seems to me
that you must be doing something pretty strange to require that :-) And
it's easy enough to access the values directly if you really need to:
IMHO, one of the big benefits of fixed point numbers is the simplicity
of bit-twiddling operations...

/*
 *  Shawn Hargreaves - shawn AT talula DOT demon DOT co DOT uk - http://www.talula.demon.co.uk/
 *  Ghoti: 'gh' as in 'enough', 'o' as in 'women', and 'ti' as in 'nation'.
 */