const.h

00001 // const.h (Defined constants for the WFMath library)
00002 //
00003 //  The WorldForge Project
00004 //  Copyright (C) 2001, 2002  The WorldForge Project
00005 //
00006 //  This program is free software; you can redistribute it and/or modify
00007 //  it under the terms of the GNU General Public License as published by
00008 //  the Free Software Foundation; either version 2 of the License, or
00009 //  (at your option) any later version.
00010 //
00011 //  This program is distributed in the hope that it will be useful,
00012 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 //  GNU General Public License for more details.
00015 //
00016 //  You should have received a copy of the GNU General Public License
00017 //  along with this program; if not, write to the Free Software
00018 //  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00019 //
00020 //  For information about WorldForge and its authors, please contact
00021 //  the Worldforge Web Site at http://www.worldforge.org.
00022 
00023 // Author: Ron Steinke
00024 // Created: 2001-12-7
00025 
00026 #ifndef WFMATH_CONST_H
00027 #define WFMATH_CONST_H
00028 
00029 #include <cfloat>
00030 // The next two aren't used in this file, but are used
00031 // everywhere else in the library.
00032 #include <cassert>
00033 #include <cmath>
00034 
00035 #ifdef _MSC_VER
00036   #if _MSC_VER < 1300
00037     #error "You are using an older version of MSVC++ with extremely poor"
00038     #error "template support. Please use at least version 7.0, where the"
00039     #error "template support is merely bad, or try a different compiler."
00040   #else
00041     // The name of this one is somewhat misleading. The problem is,
00042     // while you can _define_ specializations of template functions,
00043     // you can't _declare_ them.
00044     #define WFMATH_NO_CLASS_FUNCTION_SPECIALIZATION 1
00045     // This one means exactly what it says
00046     #define WFMATH_NO_TEMPLATES_AS_TEMPLATE_PARAMETERS 1
00047   #endif
00048 #endif
00049 
00050 // Forward declarations for all classes
00051 #include <iosfwd>
00052 
00054 namespace WFMath {
00055 
00056 // WFMath::Foo::toAtlas() has to return a definite type,
00057 // we deal with supporting both 0.4 and 0.6 by forward declaring
00058 // types which we define in the AtlasConv header
00059 class AtlasInType;
00060 class AtlasOutType;
00061 
00062 // Constants
00063 
00065 const double Pi         = 3.14159265358979323846264338327950288419716939937508;
00067 const double SqrtPi     = 1.77245385090551602729816748334114518279754945612237;
00069 const double LogPi      = 1.14472988584940017414342735135305871164729481291530;
00071 const double Sqrt2      = 1.41421356237309504880168872420969807856967187537693;
00073 const double Sqrt3      = 1.73205080756887729352744634150587236694280525381037;
00075 const double Log2       = 0.69314718055994530941723212145817656807550013436025;
00076 
00078 #define WFMATH_PRECISION_FUDGE_FACTOR 30
00079 
00080 #define WFMATH_MAX_NORM_AGE ((WFMATH_PRECISION_FUDGE_FACTOR * 2) / 3)
00081 
00083 typedef float CoordType;
00085 #define WFMATH_EPSILON          (WFMATH_PRECISION_FUDGE_FACTOR * FLT_EPSILON)
00086 
00088 #define WFMATH_MAX              FLT_MAX
00089 
00090 #define WFMATH_MIN              FLT_MIN
00091 
00092 // Basic comparisons
00093 
00094 double _ScaleEpsilon(double x1, double x2, double epsilon);
00095 double _ScaleEpsilon(const CoordType* x1, const CoordType* x2,
00096                      int length, double epsilon = WFMATH_EPSILON);
00097 
00099 
00106 template<class C>
00107 inline bool Equal(const C& c1, const C& c2, double epsilon = WFMATH_EPSILON)
00108         {return c1.isEqualTo(c2, epsilon);}
00109 
00110 bool Equal(double x1, double x2, double epsilon = WFMATH_EPSILON);
00111 // Avoid template, make sure floats are cast to doubles.
00112 inline bool Equal(float x1, float x2, double epsilon = WFMATH_EPSILON)
00113         {return Equal((double) x1, (double) x2, epsilon);}
00114 
00115 // These let us avoid including <algorithm> for the sake of
00116 // std::max() and std::min().
00117 
00118 inline CoordType FloatMax(CoordType a, CoordType b)
00119         {return (a > b) ? a : b;}
00120 inline CoordType FloatMin(CoordType a, CoordType b)
00121         {return (a < b) ? a : b;}
00122 inline CoordType FloatClamp(CoordType val, CoordType min, CoordType max)
00123         {return (min >= val) ? min : (max <= val ? max : val);}
00124 
00125 } // namespace WFMath
00126 
00127 #endif // WFMATH_CONST_H

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