csgeom/math.h
Go to the documentation of this file.00001 /* 00002 Copyright (C) 2005 by Marten Svanfeldt 00003 00004 This library is free software; you can redistribute it and/or 00005 modify it under the terms of the GNU Library General Public 00006 License as published by the Free Software Foundation; either 00007 version 2 of the License, or (at your option) any later version. 00008 00009 This library is distributed in the hope that it will be useful, 00010 but WITHOUT ANY WARRANTY; without even the implied warranty of 00011 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00012 Library General Public License for more details. 00013 00014 You should have received a copy of the GNU Library General Public 00015 License along with this library; if not, write to the Free 00016 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 00017 */ 00018 00019 #ifndef __CS_MATH_H__ 00020 #define __CS_MATH_H__ 00021 00022 #include "csutil/algorithms.h" 00023 00034 template<class T> 00035 const T& csMax (const T& a, const T& b) 00036 { 00037 if (b < a) return a; 00038 return b; 00039 } 00040 00044 template<class T> 00045 const T& csMin (const T& a, const T& b) 00046 { 00047 if (a < b) return a; 00048 return b; 00049 } 00050 00054 template<class T> 00055 void csSort (T& a, T& b) 00056 { 00057 if (b < a) 00058 CS::Swap (a, b); 00059 } 00060 00065 template<class T, class U> 00066 void csSort (T& a, T& b, U& x, U& y) 00067 { 00068 if (b < a) 00069 { 00070 CS::Swap (a, b); 00071 CS::Swap (x, y); 00072 } 00073 } 00074 00075 00079 template<class T> 00080 T csClamp (const T& a, T max, T min) 00081 { 00082 return csMin (csMax (a, min), max); 00083 } 00084 00090 template<class T> 00091 T csSmoothStep (const T& a, T max, T min) 00092 { 00093 T tmp, tmp2; 00094 if (a <= min) 00095 tmp = 0.0f; 00096 else if (a >= max) 00097 tmp = 1.0f; 00098 else 00099 { 00100 tmp2 = (a - min) / (max-min); 00101 tmp = tmp2*tmp2 * (3.0 - 2.0*tmp2); 00102 } 00103 return tmp; 00104 } 00105 00110 template<class T, class Tfactor> 00111 T csLerp (const T& a, const T& b, const Tfactor& f) 00112 { 00113 return (a + (b - a) * f); 00114 } 00115 00119 template<class T> 00120 T csSquare (const T& x) 00121 { 00122 return x * x; 00123 } 00124 00126 00127 CS_FORCEINLINE bool csFinite (float f) 00128 { 00129 #if defined (CS_HAVE_FINITEF) 00130 return finitef (f); 00131 #elif defined (CS_HAVE_STD__ISFINITE) 00132 return std::isfinite (f); 00133 #elif defined(CS_HAVE_ISFINITE) 00134 return isfinite (f); 00135 #elif defined (CS_HAVE_FINITE) 00136 return finite (f); 00137 #elif defined (CS_HAVE__FINITE) 00138 return _finite (f) != 0; 00139 #else 00140 #error Your platform has no isfinite()-alike function! 00141 #endif 00142 } 00144 CS_FORCEINLINE bool csFinite (double d) 00145 { 00146 #if defined (CS_HAVE_STD__ISFINITE) 00147 return std::isfinite (d); 00148 #elif defined(CS_HAVE_ISFINITE) 00149 return isfinite (d); 00150 #elif defined (CS_HAVE_FINITE) 00151 return finite (d); 00152 #elif defined (CS_HAVE__FINITE) 00153 return _finite (d) != 0; 00154 #else 00155 #error Your platform has no isfinite()-alike function! 00156 #endif 00157 } 00158 00160 CS_FORCEINLINE bool csNaN (float f) 00161 { 00162 #if defined (CS_HAVE_NANF) 00163 return isnanf (f); 00164 #elif defined (CS_HAVE_STD__ISNAN) 00165 return std::isnan (f); 00166 #elif defined(CS_HAVE_ISNAN) 00167 return isnan (f); 00168 #elif defined (CS_HAVE__ISNAN) 00169 return _isnan (f) != 0; 00170 #else 00171 #error Your platform has no isnan()-alike function! 00172 #endif 00173 } 00175 CS_FORCEINLINE bool csNaN (double d) 00176 { 00177 #if defined (CS_HAVE_STD__ISNAN) 00178 return std::isnan (d); 00179 #elif defined(CS_HAVE_ISNAN) 00180 return isnan (d); 00181 #elif defined (CS_HAVE__ISNAN) 00182 return _isnan (d) != 0; 00183 #else 00184 #error Your platform has no isnan()-alike function! 00185 #endif 00186 } 00187 00189 CS_FORCEINLINE bool csNormal (float f) 00190 { 00191 #if defined (CS_HAVE_NORMALF) 00192 return normalf (f); 00193 #elif defined (CS_HAVE_STD__ISNORMAL) 00194 return std::isnormal (f); 00195 #elif defined(CS_HAVE_ISNORMAL) 00196 return isnormal (f); 00197 #else 00198 return csFinite(f) && !csNaN(f); 00199 #endif 00200 } 00202 CS_FORCEINLINE bool csNormal (double d) 00203 { 00204 #if defined (CS_HAVE_STD__ISNORMAL) 00205 return std::isnormal (d); 00206 #elif defined(CS_HAVE_ISNORMAL) 00207 return isnormal (d); 00208 #else 00209 return csFinite(d) && !csNaN(d); 00210 #endif 00211 } 00213 00216 #endif //__CS_MATH_H__
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