#lang racket (require 2htdp/universe 2htdp/image (only-in lang/imageeq image=?) racket/runtime-path) (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-runtime-path dir "images0") (unless (directory-exists? dir) (make-directory dir)) (parameterize ([current-directory dir]) (for-each delete-file (directory-list))) (with-output-to-file (build-path dir "index.html") (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) (define i (bitmap "images0/i1.png")) (define j (draw-stop 5)) (unless (image=? (crop 0 0 100 100 i) j) (eprintf "this test needs to be revised -- the way 'world' writes images adds an extra pixel -- think! \n"))