Demo window system / GUI, for syndicate-2017.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

29 lines
801 B

#lang racket/base
(provide fmod
hsv->color
color-by-hash)
(require 2htdp/image)
(define (fmod a b)
(- a (* b (truncate (/ a b)))))
(define (hsv->color h s v)
(define h* (fmod (/ h 60.0) 6))
(define chroma (* v s))
(define x (* chroma (- 1 (abs (- (fmod h* 2) 1)))))
(define-values (r g b)
(cond
[(< h* 1) (values chroma x 0)]
[(< h* 2) (values x chroma 0)]
[(< h* 3) (values 0 chroma x)]
[(< h* 4) (values 0 x chroma)]
[(< h* 5) (values x 0 chroma)]
[else (values chroma 0 x)]))
(define m (- v chroma))
(define (scale x) (inexact->exact (truncate (* 255 (+ x m)))))
(make-color (scale r) (scale g) (scale b)))
(define (color-by-hash v)
(hsv->color (* 360.0 (/ (bitwise-and (equal-hash-code v) 16777215) 16777216.0)) 1 1))