Added M_PI definition in case it's ever removed, since it technically isn't ANSI spec

Frameworks/playptmod/playptmod/playptmod.c

@@ -70,6 +70,10 @@
 #include <stdlib.h> // malloc(), calloc(), free()
 #include <math.h> // floorf(), sinf()
 
+#ifndef M_PI
+#define M_PI 3.141592653589793
+#endif
+
 #define HI_NYBBLE(x) ((x) >> 4)
 #define LO_NYBBLE(x) ((x) & 0x0F)
 #define CLAMP(x, low, high)  (((x) > (high)) ? (high) : (((x) < (low)) ? (low) : (x)))