One less PI, one less Bezier.

core/include/fxcrt/fx_system.h

Index: core/include/fxcrt/fx_system.h
diff --git a/core/include/fxcrt/fx_system.h b/core/include/fxcrt/fx_system.h
index 2fbab98a1d17d1eadedcb103787d4d6bed897f81..544db6c82f1b3db73cd71580a75171b018478cf7 100644
--- a/core/include/fxcrt/fx_system.h
+++ b/core/include/fxcrt/fx_system.h
@@ -111,7 +111,10 @@ static_assert(FALSE == false, "false_needs_to_be_false");
 #endif
 
 #define FX_MIN(a, b) (((a) < (b)) ? (a) : (b))
+
+// M_PI not universally present on all platforms.
 #define FX_PI 3.1415926535897932384626433832795f
+#define FX_BEZIER 0.5522847498308f
 
 // NOTE: prevent use of the return value from snprintf() since some platforms
 // have different return values (e.g. windows _vsnprintf()), and provide