#include "AP_Math.h"

// a varient of asin() that checks the input ranges and ensures a
// valid angle as output. If nan is given as input then zero is
// returned.
float safe_asin(float v)
{
	if (isnan(v)) {
		return 0;
	}
	if (v >= 1.0) {
		return PI/2;
	}
	if (v <= -1.0) {
		return -PI/2;
	}
	return asin(v);
}