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sketch_2021_04_21.py

# you will need http://py5.pixora.io's sketch runner for imported mode

def setup():
    global first_seg
    size(500, 500)
    stroke_weight(9)
    color_mode(HSB)
    seg = Segment((100, 100), (100, 100))
    for _ in range(10):
        seg = Segment((100, 100), (100,100), seg)

def draw():
    background(240)
    Segment.segments[0].drag((mouse_x, mouse_y))    
    Segment.update_all()

class Segment:
    
    segments = []
    seg_length = 20
    
    def __init__(self, start, end, link=None):
        self.start = start
        self.end = end
        self.link = link
        self.segments.append(self)
            
    def drag(self, new_start=None):
        if new_start is None and self.link is not None:
            new_start = self.link.end
        if new_start:                            
            xs, ys = self.start = new_start 
            angle = self.angle()
            xe = xs - cos(angle) * self.seg_length
            ye = ys - sin(angle) * self.seg_length
            self.end = xe, ye
 
    def draw(self):
        xs, ys = self.start
        xe, ye = self.end
        line(xs, ys, xe, ye)
        
    def angle(self):
        xs, ys = self.start
        xe, ye = self.end
        return atan2(ys - ye, xs - xe)        
        
    @classmethod
    def update_all(cls):
        for i, s in enumerate(cls.segments):
            s.drag()
            stroke(i * 10, 200, 100, 150)
            s.draw()
        
def mouse_wheel(e):
    Segment.seg_length += e.getCount()