//
//
//Original author: Gordon Griesel
//Date: November 2023
//Purpose: 3350 program
//
//See instructions on web page to produce a unit-test
//for the normalize member function.
//
#include <stdlib.h>
#include <stdio.h>
#include <math.h>

typedef double Flt;

class Vec {
private:
	Flt x;
	Flt y;
public:
	Vec() {
		x = y = 0.0;
	}
	Vec(Flt a, Flt b) {
		x = a;
		y = b;
	}
	Flt getx() { return x; }
	Flt gety() { return y; }
	void make(Flt a, Flt b) {
		x = a;
		y = b;
	}
	Flt normalize() {
	    //Normalize a vector.
	    //Return the length of the vector.
	    //
	    //input: the components of a vector
	    //output: the normalized vector length is returned
	    //        the vector argument is scaled to a length of 1.0
	    //
	    //A degenerate vector may cause an error condition.
	    //Length of 0.0 will be returned,
	    //and a vector with length 1.0.
	    //
	    //calculate the vector dot product with itself ...
	    Flt dot = x*x + y*y;
	    //check for degenerate vector...
	    if (dot == 0.0) {
	        //set a vector of length 1.0
	        //printf("ERROR vector magnitude is zero.\n");
	        x = 1.0;
	        y = 0.0;
	        return 0.0;
	    }
	    //vector has a magnitude so continue.
	    Flt len = sqrt(dot);
	    Flt ooleng = 1.0 / len;
	    x *= ooleng;
	    y *= ooleng;
	    return len;
	}
};

//Array of vector values
const Flt arr[] = {
  1.0,   0.0,
  1.0,   1.0,
 -1.2,   2.5,
 99.9,  99.9,
  2.2,  -1.2,
  0.0,   0.0
};


int main(int argc, char *argv[])
{
    //Program to calculate vector normalization and length.
	//
    printf("                                    \n");
    printf("3350 Software Engineering           \n");
    printf("                                    \n");
    printf("Calculation of vector lengths:      \n");
    printf("                                    \n");
    printf("     x         y         length     \n");
    printf("     --------  --------  ---------- \n");
    //read until sentinel found.
    int i=0;
    Vec vec( arr[i*2+0], arr[i*2+1] );
    do {
        Flt ret = vec.normalize();
        printf("%3i  %8.5lf  %8.5lf  %10.5lf\n",
                i+1, arr[i*2+0], arr[i*2+1], ret);
        ++i;
        vec.make(arr[i*2+0], arr[i*2+1]);
    } while (!(vec.getx() == 0.0 && vec.gety() == 0.0));
    //
    printf("\nProgram complete.\n\n");
    return 0;
}