Lines.pde

    
    ArrayList<Line> lines = new ArrayList<Line>();

    public void setup(){
        size(800,800);
        colorMode(HSB);
        background(0);
        strokeWeight(1);
        frameRate(30);
        createLine();
        drawLines();
    }

    public void draw(){
        //background(0);
        applyLine();
        drawLines();
    }

    void createLine(){
        lines.add(new Line(new PVector(0, 0), new PVector(0,width)));
    }

    void applyLine(){
        Line last = lines.get(lines.size()-1);
        float size = last.origin.dist(last.target);
        float angle = getAngle(last.origin, last.target);
        PVector newTarget = getPVectorAtAngle(last.target, size-1, angle-89);
        lines.add(new Line(last.target, newTarget));
    }

    void drawLines(){
        for(Line l : lines){
            l.draw();
        }
    }

    class Line{
        PVector origin, target;
        public Line(PVector origin, PVector target){
            this.origin = origin;
            this.target = target;
        }

        void draw(){
            stroke(map(getAngle(origin, target), 0, 360, 0, 200), 255,255);
            line(origin.x, origin.y, target.x, target.y);
        }
    }

    public PVector getPVectorAtAngle(PVector center, float radius, float angle) {
        return new PVector(center.x + radius * cos(angle * PI / 180), center.y + radius * sin(angle * PI / 180));
    }

    public float getAngle(PVector origin, PVector end) {
        return degrees(atan2(end.y - origin.y, end.x - origin.x));
    }