// CSE143 Sp01 Homework 2 Sample Solution
// location.cpp - implementation of class Location
// HP  4/01

#include <string>
#include <cmath>
using namespace std;

#include "location.h"

const double PI = 3.1415926535;

// Construct a Location with coordinates <xloc,yloc>
Location::Location(double xloc, double yloc) {
	x = xloc;
	y = yloc;
}

// Default constructor - initialize this Location to <0,0>
Location::Location() {
	x = 0.0;
	y = 0.0;
}

// = Distance from this Location to Location other
double Location::distanceTo(Location other) {
	double dx = x - other.x;
	double dy = y - other.y;
	return sqrt(dx*dx + dy*dy);
}

// compass directions
const string direction[] =
	{"north", "northeast", "east", "southeast",
	"south", "southwest", "west", "northwest"};

// = Direction from this Location to Location other, as a string:
// north, northeast, east, southeast, south, southwest, west, northwest
string Location::directionTo(Location other) {
	// strategy: calculate the angle between 0 and 360, increase by 22.5 degrees
	// modulo 360 and round to the nearest int to get a number between 0 and 45 for 
	// north, 45 to 90 for northeast, etc., then divide by 45 to get the index of 
	// the appropriate word in array directions.

	double	a;		// angle from north +-180
	double	angle;	// angle from 0-360
	int		deg;	// adjusted angle

	a = atan2(other.x - x, other.y - y) * 180 / PI;
	if (a > 0) {
		angle = a;
	} else {
		angle = 360.0 + a;
	}
	deg = ((int) (angle + 22.5 + 0.5)) % 360;
	return direction[deg/45];
}