25 lines
795 B
Racket
25 lines
795 B
Racket
;; The first three lines of this file were inserted by DrRacket. They record metadata
|
|
;; about the language level of this file in a form that our tools can easily process.
|
|
#reader(lib "htdp-advanced-reader.ss" "lang")((modname on-release-no-key) (read-case-sensitive #t) (teachpacks ()) (htdp-settings #(#t constructor repeating-decimal #t #t none #f ())))
|
|
;; Any key inflates the balloon
|
|
|
|
(require 2htdp/image)
|
|
(require 2htdp/universe)
|
|
|
|
(define large 50)
|
|
|
|
(define (balloon b)
|
|
(if (<= b 10)
|
|
(text "press any key now" 22 'red)
|
|
(circle b "solid" "red")))
|
|
|
|
(define (blow-up b k) large)
|
|
|
|
(define (deflate b) (max (- b 1) 1))
|
|
|
|
(big-bang 20
|
|
(on-release blow-up)
|
|
(on-tick deflate)
|
|
(to-draw balloon 200 200)
|
|
(stop-when (lambda (w) (>= w large))))
|