shoebot mouse example

from math import sin, cos
from random import random

size(900,200)

speed(30)

def setup():
    global cnt
    cnt = 0.0
    global tic
    tic = 0
    global tail
    tail = []

def store():
    x, y = MOUSEX, MOUSEY
    tail.append([x, y, 90 + 10 * cos(cnt), cnt])

def draw():
    global tic
    if tic % 1 == 0:
        store()

    translate(-50,-50)
    global cnt
    removes = []
    for i in range(len(tail)):
        x, y, t, col = tail[i]
        c = t * 1.0 / 100
        fill(c, 0.5*cos(col), sin(col))
        oval(x + sin(cnt), y + cos(cnt) - t / 4 * sin(t / 10.0) + sin(cnt), t, t)
        rect(x + sin(cnt), y + cos(cnt) - t / 4 * sin(t / 10.0) + sin(cnt), t, t, 0.95)
        if t < 0:
            removes.append(i)

        tail[i] = x, y, t-1, col

    for i in removes:
        del tail[i]

    cnt += 0.10
    tic += 1