moved helper functions into utils.h, cleaned up

utils.h

@@ -0,0 +1,36 @@
+
+#ifndef UTILS_H
+#define UTILS_H
+#include <stdint.h>
+#include <time.h>
+
+int64_t gcd(int64_t a, int64_t b)
+{
+	int64_t c;
+	while ((c = a % b)) {
+		a = b;
+		b = c;
+	}
+	return b;
+}
+
+float fclampf(float x, float min, float max)
+{
+	float tmp = x < min ? min : x;
+	return tmp > max ? max : tmp;
+}
+
+float flerpf(float a, float b, float x)
+{
+	return a - a * x + b * x;
+}
+
+char *string_time(char *fmt)
+{
+	static char s[64];
+	time_t now = time(0);
+	strftime(s, sizeof(s), fmt, localtime(&now));
+	return s;
+}
+#endif
+