irrlicht/source/Irrlicht/irrMathFastCompat.h

53 lines
1.6 KiB
C++

// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h
#ifndef __IRR_FAST_MATH_COMPAT_H_INCLUDED__
#define __IRR_FAST_MATH_COMPAT_H_INCLUDED__
#include "irrMath.h"
namespace irr
{
namespace core
{
// IRRLICHT_FAST_MATH functions which I wanted to kick out because they return
// wrong results. But last time I proposed that I've been asked to keep them for
// Burnings software renderer. So to avoid changing that accidentally or messing up
// it's speed I'll keep them around, but only as internal header.
// They should not be used otherwise any longer.
// Some examples for unexpected results when using this with IRRLICHT_FAST_MATH:
// Input 1, expected 1, got 0
// Input 3, expected 3, got 2
// Input -1.40129846e-45, expected -1, got 0
REALINLINE s32 floor32_fast(f32 x)
{
return (s32) floorf ( x );
}
// Some examples for unexpected results when using this with IRRLICHT_FAST_MATH:
// Input 1.40129846e-45, expected 1, got 0
// Input -1, expected -1, got 0
// Input -3, expected -3, got -2
REALINLINE s32 ceil32_fast ( f32 x )
{
return (s32) ceilf ( x );
}
// Some examples for unexpected results when using this with IRRLICHT_FAST_MATH:
// Input 0.5, expected 1, got 0
// Input 2.5, expected 3, got 2
// Input -1.40129846e-45, expected -nan(ind), got -inf
// Input -2.80259693e-45, expected -nan(ind), got -inf
REALINLINE s32 round32_fast(f32 x)
{
return (s32) round_(x);
}
} // end namespace core
} // end namespace irr
#endif // __IRR_FAST_MATH_COMPAT_H_INCLUDED__