/******************************************************************************
 *  
 * Name     : Scott Kristjanson
 * Number   : 123456789
 * email    : skristja@sfu.ca 
 * Course   : Cmpt135
 * Assmt    : 1
 * Question : B2
 *
 * File     : Distance.cpp
 * 
 * This implements the Distance program for Assignment 1 Question B2.
 * This program prompts the user for two pairs of coordinates, stores them
 * in two Point structs, then computes the distance between these points to 
 * three decimal points.
 *
 ******************************************************************************/

#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>

using namespace std;


/******************************************************************************
 *
 * Point
 * =====
 * Data structure that stores the (x,y) coordinates for a point on a plane.
 * 
 ******************************************************************************/
struct Point {
    int x;
    int y;
};

/******************************************************************************
 * 
 * input
 * =====
 * Reads in two integer values of cin and stores them in point
 * 
 * Inputs:
 *    point - updated with the user entered x and y coordinates
 * 
 * Returns:
 *    point - updated with new coordinates
 * 
 ******************************************************************************/
void input(Point& point) {
    cin >> point.x >> point.y;
}


/******************************************************************************
 * 
 * output
 * ======
 * Displays the coordinates of the specified point in the form (x,y)
 * 
 * Inputs:
 *    point - the Point to be displayed to cout
 * 
 * Returns:
 *    Nothing
 * 
 ******************************************************************************/
void output(const Point& point) {
    cout << "(" << point.x << "," << point.y << ")";
}


/******************************************************************************
 * 
 * Main function
 * =============
 * Main promts for two points and computes the distance between them.
 *
 ******************************************************************************/
int main(int argc, char **argv) {
    Point  point1,  point2;
    int    dx,      dy;
    double distance;
    
    cout << "Specify point1 integer coordinates as x y: ";
    input(point1);
        
    cout << "Specify point2 integer coordinates as x y: ";
    input(point2);

    // Calculate the distance from point1 to point2
    dx       = abs(point1.x - point2.x);
    dy       = abs(point1.y - point2.y);
    distance = sqrt(dx*dx + dy*dy);
    
    // Set up cout to display doubles with 3 decimal places
    cout.setf(ios::fixed);
    cout.setf(ios::showpoint);
    cout.precision(3);
    
    // Display the distance 
    cout << "Distance from point1 ";
    output(point1);
    cout << " to point2 ";
    output(point2);
    cout << " = " << distance << endl;
}