draw lines following the mouse in rainbow colours; base stroke thickness on mouse speed

rainbow-strokes.clj

(ns mouse-interactivity.core
  (:require [quil.core :refer :all]))

(def max-stroke-weight 40)

(defn setup []
  (background 255)
  (color-mode :hsb)
  (smooth))

(defn draw []
  (stroke (mod (frame-count) 360) 255 255)
  (let [speed-x (abs (- (mouse-x) (pmouse-x)))
        speed-y (abs (- (mouse-y) (pmouse-y)))
        new-weight (mod (+ speed-x speed-y) max-stroke-weight)]
    (stroke-weight new-weight)
    (line (mouse-x) (mouse-y) (pmouse-x) (pmouse-y))))

(defsketch example
  :title "Example"
  :setup setup
  :draw draw
  :size [400 400])

(defn -main [& args])