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Re: your mail



On Wed, May 25, 2016 at 08:59:12AM -0400, Christos Zoulas wrote:
> On May 25,  1:36pm, bouyer%antioche.eu.org@localhost (Manuel Bouyer) wrote:
> -- Subject: 
> 
> | Hello,
> | in xsrc/external/mit/glu/dist/include/GL/glu.h:
> | revision 1.2
> | date: 2014/12/19 19:07:46;  author: christos;  state: Exp;  lines: +6 -0
> | branches:  1.2.2;
> | use DBL_MAX instead of 1.0e150...
> | +/* GLdouble is double in gl.h so we are DBL_MAX */
> | +#include <limits.h>    /* Not a good place to do that, but... */
> | +#ifndef DBL_MAX
> |  #define GLU_TESS_MAX_COORD 1.0e150
> | +#else
> | +#define GLU_TESS_MAX_COORD DBL_MAX
> | +#endif
> | 
> | can you explain why ?
> | In libtess, values like -2 * GLU_TESS_MAX_COORD, 4 * GLU_TESS_MAX_COORD
> | are used, which ends up being +/-inf and causes bad things to happen.
> 
> Well, DBL_MAX is supposed to be defined... This was for the vax (it does
> not fit e150).

yes it's defined but it's way too large. 2 * DBL_MAX and 4 * DBL_MAX
both gives inf, and then ((2 * DBL_MAX) < (4 * DBL_MAX)) is false
when it should be true. Or ((2 * DBL_MAX) == (4 * DBL_MAX)) is
true when it should be false.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--


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