#include "hwo/fixpoint.h"

/* fp_acos()	returns: 0..180 */
fixpoint_t fp_acos(fixpoint_t cos)
{
	if ((cos >= fp_make(1)))
		return 0;
	if (cos == fp_make(0))
		return fp_make(90);
	if (cos == fp_make(-1))
		return fp_make(180);
	if (cos > 0)
		return fp_make(90) - fp_sin_lookup_reverse(cos);
	if (cos < 0)
		return fp_make(90) + fp_sin_lookup_reverse(-cos);
	return 0;
};