Fixed many casting issues.

src/display/primitives/skywall.c

@@ -25,7 +25,7 @@ void skywallInit(primitive_t *primitive) {
     if(SKYWALL_SLICE_COUNT == i) {
       r = 0;
     } else {
-      r = p * (float)M_PI * 2;// Convert % to radians
+      r = p * MATH_PI * 2.0f;// Convert % to radians
     }
 
     // Determine the X/Z for the given radian