Finish e3setup/main.c

Also add ext_math.h file for better math

include/ext_math.h

@@ -0,0 +1,21 @@
+#ifndef _EXT_MATH_H
+#define _EXT_MATH_H
+
+#include "math.h"
+#include "dolphin/mtx.h"
+
+typedef struct vector2 {
+	float x;
+	float y;
+} Vector2;
+
+#define ABS(x) (((x) < 0) ? -(x) : (x))
+
+#define VECDistanceXZ(a, b) sqrtf((((a)->x-(b)->x)*((a)->x-(b)->x))+(((a)->z-(b)->z)*((a)->z-(b)->z)))
+#define VECMagXZ(a) sqrtf(((a)->x*(a)->x)+((a)->z*(a)->z))
+
+#define sind(x) sin(M_PI*(x)/180.0)
+#define cosd(x) cos(M_PI*(x)/180.0)
+#define atan2d(y, x) (180.0*(atan2((y), (x)) / M_PI))
+
+#endif