/usr/include/crystalspace-2.0/cstool/fogmath.h is in libcrystalspace-dev 2.0+dfsg-1build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 | /*
Copyright (C) 2004 by Anders Stenberg
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef __CS_CSTOOL_FOGMATH_H__
#define __CS_CSTOOL_FOGMATH_H__
/**\file
* Fog math utilities.
*/
/// Fog math utilities.
class csFogMath
{
public:
/**
* Calculates fog density for a certain depth in the range [0..1]
*/
static inline float Ramp (float depth)
{
return 1.0 - exp (-depth*7);
//return depth;
}
/// Compute fog opacity at a given distance.
/* @@@ NOTE: Basically the same computation that's done when using fog
* texgen from the glfixed VP - means, keep this function in sync! */
static inline float OpacityAtDistance (float density, float dist)
{
return Ramp (density*(dist-0.1f));
}
/// Inverse of OpacityAtDistance
static inline float DistanceForOpacity (float density, float opacity)
{
return -(log(-opacity+1.0f)/(density * 7.0f)) + 0.1f;
}
};
#endif // __CS_CSTOOL_FOGMATH_H__
|