[Bf-blender-cvs] [535de7e] master: Comment for math defines, also add M_PI_4

[Campbell Barton]

Commit: 535de7ec1fee94eae1769630b512c6ef4eb5bcad
Author: Campbell Barton
Date:   Sat Jan 31 17:17:12 2015 +1100
Branches: master
https://developer.blender.org/rB535de7ec1fee94eae1769630b512c6ef4eb5bcad

Comment for math defines, also add M_PI_4

===================================================================

M	source/blender/blenlib/BLI_math_base.h

===================================================================

diff --git a/source/blender/blenlib/BLI_math_base.h b/source/blender/blenlib/BLI_math_base.h
index 2bc23c8..daa7db8 100644
--- a/source/blender/blenlib/BLI_math_base.h
+++ b/source/blender/blenlib/BLI_math_base.h
@@ -42,10 +42,13 @@
 #endif
 
 #ifndef M_PI
-#define M_PI        3.14159265358979323846
+#define M_PI        3.14159265358979323846  /* pi */
 #endif
 #ifndef M_PI_2
-#define M_PI_2      1.57079632679489661923
+#define M_PI_2      1.57079632679489661923  /* pi/2 */
+#endif
+#ifndef M_PI_4
+#define M_PI_4      0.78539816339744830962  /* pi/4 */
 #endif
 #ifndef M_SQRT2
 #define M_SQRT2     1.41421356237309504880  /* sqrt(2) */
@@ -60,22 +63,22 @@
 #define M_SQRT1_3   0.57735026918962576450  /* 1/sqrt(3) */
 #endif
 #ifndef M_1_PI
-#define M_1_PI      0.318309886183790671538
+#define M_1_PI      0.318309886183790671538  /* 1/pi */
 #endif
 #ifndef M_E
-#define M_E             2.7182818284590452354
+#define M_E         2.7182818284590452354  /* e */
 #endif
 #ifndef M_LOG2E
-#define M_LOG2E         1.4426950408889634074
+#define M_LOG2E     1.4426950408889634074  /* log_2 e */
 #endif
 #ifndef M_LOG10E
-#define M_LOG10E        0.43429448190325182765
+#define M_LOG10E    0.43429448190325182765  /* log_10 e */
 #endif
 #ifndef M_LN2
-#define M_LN2           0.69314718055994530942
+#define M_LN2       0.69314718055994530942  /* log_e 2 */
 #endif
 #ifndef M_LN10
-#define M_LN10          2.30258509299404568402
+#define M_LN10      2.30258509299404568402  /* log_e 10 */
 #endif
 
 #if defined(__GNUC__)