Data commit

Task/Image-noise/Racket/image-noise.rkt

@@ -0,0 +1,26 @@
+#lang racket
+(require 2htdp/image 2htdp/universe)
+
+(define black (color   0   0   0 255))
+(define white (color 255 255 255 255))
+
+(define-struct world (last fps))
+
+(define (noise w h)
+  (color-list->bitmap
+   (for*/list ([x (in-range w)] [y (in-range h)])
+     (if (zero? (random 2)) black white))
+   w h))
+
+(define (draw w)
+  (underlay/xy
+   (noise 320 240) 0 0
+   (text (number->string (world-fps w)) 64 "Red")))
+
+(define (handle-tick w)
+  (define cm (current-inexact-milliseconds))
+  (make-world cm (exact-floor (/ 1000.0 (- cm (world-last w))))))
+
+(big-bang (make-world 1 0)
+          [on-draw draw]
+          [on-tick handle-tick (/ 1. 120)])