xrCore/math_constants.h: use constexpr

Author: Xottab-DUTY

src/xrCore/math_constants.h

@@ -11,26 +11,26 @@
 
 // Constants
 // Epsilon's, to use as difference limit when comparing float's.
-const float EPS_S = 0.0000001f;
-const float EPS   = 0.0000100f;
-const float EPS_L = 0.0010000f;
+constexpr float EPS_S = 0.0000001f;
+constexpr float EPS   = 0.0000100f;
+constexpr float EPS_L = 0.0010000f;
 
 #ifdef M_SQRT1_2
 #undef M_SQRT1_2
 #endif
 // XXX: The following section contains constants with a _tad_ many decimals to fit in a float. :-)
 //      They used to be macro's, so they could be used as double too.
-const float M_SQRT1_2 = 0.7071067811865475244008443621048f;//490;
+constexpr float M_SQRT1_2 = 0.7071067811865475244008443621048f;//490;
 
-const float M_PI = 3.1415926535897932384626433832795f;
-const float PI = 3.1415926535897932384626433832795f;
-const float PI_MUL_2 = 6.2831853071795864769252867665590f;
-const float PI_MUL_3 = 9.4247779607693797153879301498385f;
-const float PI_MUL_4 = 12.566370614359172953850573533118f;
-const float PI_MUL_6 = 18.849555921538759430775860299677f;
-const float PI_MUL_8 = 25.132741228718345907701147066236f;
-const float PI_DIV_2 = 1.5707963267948966192313216916398f;
-const float PI_DIV_3 = 1.0471975511965977461542144610932f;
-const float PI_DIV_4 = 0.7853981633974483096156608458199f;
-const float PI_DIV_6 = 0.5235987755982988730771072305466f;
-const float PI_DIV_8 = 0.3926990816987241548078304229099f;
+constexpr float M_PI = 3.1415926535897932384626433832795f;
+constexpr float PI = 3.1415926535897932384626433832795f;
+constexpr float PI_MUL_2 = 6.2831853071795864769252867665590f;
+constexpr float PI_MUL_3 = 9.4247779607693797153879301498385f;
+constexpr float PI_MUL_4 = 12.566370614359172953850573533118f;
+constexpr float PI_MUL_6 = 18.849555921538759430775860299677f;
+constexpr float PI_MUL_8 = 25.132741228718345907701147066236f;
+constexpr float PI_DIV_2 = 1.5707963267948966192313216916398f;
+constexpr float PI_DIV_3 = 1.0471975511965977461542144610932f;
+constexpr float PI_DIV_4 = 0.7853981633974483096156608458199f;
+constexpr float PI_DIV_6 = 0.5235987755982988730771072305466f;
+constexpr float PI_DIV_8 = 0.3926990816987241548078304229099f;