#lang racket (require 2htdp/universe 2htdp/image (only-in lang/imageeq image=?)) (define (draw-number n) (place-image (text (number->string n) 44 'red) 50 50 (empty-scene 100 100))) (define (draw-stop n) (place-image stop 50 50 (empty-scene 100 100))) (define stop (text "STOP" 44 'red)) (define dir "images0") (unless (directory-exists? dir) (make-directory dir)) (parameterize ([current-directory dir]) (for-each delete-file (directory-list))) (with-output-to-file (format "./~a/index.html" dir) (lambda () (displayln "

")) #:exists 'replace) (define final-world (big-bang 0 (on-tick add1) (stop-when (curry = 5) draw-stop) (on-draw draw-number) (record? dir))) (sleep 1) (unless (image=? (bitmap "images0/i1.png") (draw-stop 5)) (fprintf (current-error-port) "this test needs to be revised -- the way 'world' writes images adds an extra pixel -- think! \n"))