An implementation of Bresenham's line algorithm

bresenham.js

// Bresenham's line algorithm
var getRay = function(x0,y0,x1,y1){
        var dx = Math.abs(x1-x0);
        var dy = Math.abs(y1-y0);
        var sx = x0 < x1 ? 1 : -1;
        var sy = y0 < y1 ? 1 : -1;
        var err = dx-dy;
        
        var ray = [];
        while(x0!=x1 || y0!=y1){
                ray.push([x0,y0]);
                var e2 = 2*err;
                if(e2>-dy){
                        err = err - dy;
                        x0 += sx;
                }
                if(e2<dx){
                        err = err + dx;
                        y0 += sy;
                }
        }
        return ray;
}