Adding a lot of math constants from math.h.

Author: cgore

pixie/math.pxi

@@ -23,4 +23,19 @@
   (i/defcfn ceil)
   (i/defcfn fabs)
   (i/defcfn floor)
-  (i/defcfn fmod))
+  (i/defcfn fmod)
+
+  (i/defconst M_E)             ; base of natural logarithm, e
+  (i/defconst M_LOG2E)         ; log2(e)
+  (i/defconst M_LOG10E)        ; log10(e)
+  (i/defconst M_LN2)           ; ln(2)
+  (i/defconst M_LN10)          ; ln(10)
+  (i/defconst M_PI)            ; pi
+  (i/defconst M_PI_2)          ; pi / 2
+  (i/defconst M_PI_4)          ; pi / 4
+  (i/defconst M_1_PI)          ; 1 / pi
+  (i/defconst M_2_PI)          ; 2 / pi
+  (i/defconst M_2_SQRTPI)      ; 2 / sqrt(pi)
+  (i/defconst M_SQRT2)         ; sqrt(2)
+  (i/defconst M_SQRT1_2))      ; sqrt(1/2)
+