First checkin for OpenMesh 2.0

git-svn-id: http://www.openmesh.org/svnrepo/OpenMesh/trunk@2 fdac6126-5c0c-442c-9429-916003d36597

Core/Geometry/MathDefs.hh

@@ -0,0 +1,148 @@
+/*===========================================================================*\
+ *                                                                           *
+ *                               OpenMesh                                    *
+ *        Copyright (C) 2003 by Computer Graphics Group, RWTH Aachen         *
+ *                           www.openmesh.org                                *
+ *                                                                           *
+ *---------------------------------------------------------------------------*
+ *                                                                           *
+ *                                License                                    *
+ *                                                                           *
+ *  This library is free software; you can redistribute it and/or modify it  *
+ *  under the terms of the GNU Lesser General Public License as published    *
+ *  by the Free Software Foundation, version 2.1.                            *
+ *                                                                           *
+ *  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        *
+ *  Lesser General Public License for more details.                          *
+ *                                                                           *
+ *  You should have received a copy of the GNU Lesser General Public         *
+ *  License along with this library; if not, write to the Free Software      *
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.                *
+ *                                                                           *
+\*===========================================================================*/
+
+#ifndef MATHDEFS_HH
+#define MATHDEFS_HH
+
+#include <math.h>
+#include <float.h>
+
+#ifndef M_PI
+  #define M_PI      3.14159265359
+#endif
+
+namespace OpenMesh
+{
+
+/** comparison operators with user-selected precision control
+*/
+template <class T, typename Real>
+inline bool is_zero(const T& _a, Real _eps)
+{ return fabs(_a) < _eps; }
+
+template <class T1, class T2, typename Real>
+inline bool is_eq(const T1& a, const T2& b, Real _eps)
+{ return is_zero(a-b, _eps); }
+
+template <class T1, class T2, typename Real>
+inline bool is_gt(const T1& a, const T2& b, Real _eps)
+{ return (a > b) && !is_eq(a,b,_eps); }
+
+template <class T1, class T2, typename Real>
+inline bool is_ge(const T1& a, const T2& b, Real _eps)
+{ return (a > b) || is_eq(a,b,_eps); }
+
+template <class T1, class T2, typename Real>
+inline bool is_lt(const T1& a, const T2& b, Real _eps)
+{ return (a < b) && !is_eq(a,b,_eps); }
+
+template <class T1, class T2, typename Real>
+inline bool is_le(const T1& a, const T2& b, Real _eps)
+{ return (a < b) || is_eq(a,b,_eps); }
+
+/*const float flt_eps__ = 10*FLT_EPSILON;
+const double dbl_eps__ = 10*DBL_EPSILON;*/
+const float flt_eps__ = (float)1e-05;
+const double dbl_eps__ = 1e-09;
+
+inline float eps__(float) 
+{ return flt_eps__; }
+
+inline double eps__(double)
+{ return dbl_eps__; }
+
+template <class T>
+inline bool is_zero(const T& a)
+{ return is_zero(a, eps__(a)); }
+
+template <class T1, class T2>
+inline bool is_eq(const T1& a, const T2& b)
+{ return is_zero(a-b); }
+
+template <class T1, class T2>
+inline bool is_gt(const T1& a, const T2& b)
+{ return (a > b) && !is_eq(a,b); }
+
+template <class T1, class T2>
+inline bool is_ge(const T1& a, const T2& b)
+{ return (a > b) || is_eq(a,b); }
+
+template <class T1, class T2>
+inline bool is_lt(const T1& a, const T2& b)
+{ return (a < b) && !is_eq(a,b); }
+
+template <class T1, class T2>
+inline bool is_le(const T1& a, const T2& b)
+{ return (a < b) || is_eq(a,b); }
+
+/// Trigonometry/angles - related
+
+template <class T>
+inline T sane_aarg(T _aarg)
+{
+  if (_aarg < -1)
+  {
+    _aarg = -1;
+  }
+  else if (_aarg >  1)
+  {
+    _aarg = 1;
+  }
+  return _aarg;
+}
+
+/** returns the angle determined by its cos and the sign of its sin
+    result is positive if the angle is in [0:pi]
+    and negative if it is in [pi:2pi]
+*/
+template <class T>
+T angle(T _cos_angle, T _sin_angle)
+{//sanity checks - otherwise acos will return nan
+  _cos_angle = sane_aarg(_cos_angle);
+  return (T) _sin_angle >= 0 ? acos(_cos_angle) : -acos(_cos_angle);
+}
+
+template <class T>
+inline T positive_angle(T _angle)
+{ return _angle < 0 ? (2*M_PI + _angle) : _angle; }
+
+template <class T>
+inline T positive_angle(T _cos_angle, T _sin_angle)
+{ return positive_angle(angle(_cos_angle, _sin_angle)); }
+
+template <class T>
+inline T deg_to_rad(const T& _angle)
+{ return M_PI*(_angle/180); }
+
+template <class T>
+inline T rad_to_deg(const T& _angle)
+{ return 180*(_angle/M_PI); }
+
+inline double log_(double _value)
+{ return log(_value); }
+
+};//namespace OpenMesh
+
+#endif//MATHDEFS_HH