hw2 reference

by SunnyHsu

JavaScript

function line (p1,q1,p2,q2) {
	// ax + by + c = 0
    var a = q2 - q1;
    var b = p1 - p2;
    var c = p2*q1 - p1*q2;
    return [a,b,c];
}

function solve (coeff1, coeff2) {
    var a1 = coeff1[0], b1 = coeff1[1], c1 = coeff1[2];
    var a2 = coeff2[0], b2 = coeff2[1], c2 = coeff2[2];
    
    var denom = a2*b1 - a1*b2;
    
    var x = (b2*c1 - b1*c2)/denom;
    var y = -(a2*c1 - a1*c2)/denom;
    return [x,y];
}

var pa = [0,0], pb = [2,2];
var pc = [0,1], pd = [1,0];

var line1 = line (pa[0],pa[1], pb[0],pb[1]);
var line2 = line (pc[0],pc[1], pd[0],pd[1]);
console.log (line1);
console.log (line2);
console.log (solve (line1, line2));