Question

So I am trying to make a program that grows the image “HI” using big-bang. I have it placed in the center of the canvas. I want the text size to start at 1 and stop growing when the size reaches 80. I’ve added the on-tick but it still won’t start at 1 and grow. Any ideas on what I am doing wrong?

edit-

    (require 2htdp/image)
    (require 2htdp/universe)

    (define word "HELLO WORLD" )

    (define (draw-world world )
      (place-image (text word world  "olive")
                   240 210
                   (empty-scene 500 300)))


         (define (next t)
  (cond [(>= (draw-world t) 80) t]
        [else (+ t 1)]))

    (big-bang 1
              (on-tick add1)
              (to-draw draw-world)
              (stop-when zero?))

Answer 1

There are a few things. The most important one is in draw-world
where you draw a text of size 11. If you instead draw a text of size world then your text will have the same size as the current world.

(text word world "olive")

After fixing that bug, you will immediately spot the next thing to fix.

Update:

(define (stop? a-world)
  (<= a-world 80))