Dogcows Code - chaz/yoink/blob - src/math.hh

   1
   2 /*******************************************************************************
   3
   4  Copyright (c) 2009, Charles McGarvey
   5  All rights reserved.
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  27 *******************************************************************************/
  28
  29 #ifndef _MATH_HH_
  30 #define _MATH_HH_
  31
  32 /**
  33  * @file math.hh
  34  * General math-related types and functions.
  35  */
  36
  37 #include <cmath>
  38 #include <cml/cml.h>
  39
  40
  41 namespace dc {
  42
  43
  44 typedef double                          scalar;                         ///< Scalar variable.
  45
  46 typedef cml::vector2d           vector2;
  47 typedef cml::vector3d           vector3;
  48 typedef cml::vector4d           vector4;
  49
  50 typedef cml::matrix33d_c        matrix3;
  51 typedef cml::matrix44d_c        matrix4;
  52
  53 typedef cml::quaterniond_p      quaternion;
  54
  55 typedef cml::vector4f           color;
  56
  57
  58 // Here's a simple way to check the equality of floating-point variables more
  59 // reliably using approximation.
  60
  61 const scalar default_epsilon = 0.00001;         ///< @see equals()
  62
  63
  64 /**
  65  * Check the equality of scalars with a certain degree of error allowed.
  66  */
  67
  68 inline bool equals(scalar a, scalar b, scalar epsilon = default_epsilon)
  69 {
  70         return std::abs(a - b) < epsilon;
  71 }
  72
  73
  74 } // namespace dc
  75
  76 #endif // _MATH_HH_
  77