Data commit

Task/Bitmap-Read-a-PPM-file/Racket/bitmap-read-a-ppm-file.rkt

@@ -0,0 +1,22 @@
+#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))