#lang racket
(require racket/draw)

(define (read-ppm port)
  (parameterize ([current-input-port port])
    (define magic (read))
    (define width (read))
    (define height (read))
    (define maxcol (read))
    (define bm (make-object bitmap% width height))
    (define dc (new bitmap-dc% [bitmap bm]))
    (send dc set-smoothing 'unsmoothed)
    (define (adjust v) (* 255 (/ v maxcol)))
    (for/list ([x width])
      (for/list ([y height])
        (define red (read))
        (define green (read))
        (define blue (read))
        (define color (make-object color% (adjust red) (adjust green) (adjust blue)))
        (send dc set-pen color 1 'solid)
        (send dc draw-point x y)))
    bm))