RosettaCodeData/Task/Bitmap-Write-a-PPM-file/Scheme/bitmap-write-a-ppm-file-1.ss

23 lines
773 B
Scheme

(define (write-ppm image file)
(define (write-image image)
(define (write-row row)
(define (write-colour colour)
(if (not (null? colour))
(begin (write-char (integer->char (car colour)))
(write-colour (cdr colour)))))
(if (not (null? row))
(begin (write-colour (car row)) (write-row (cdr row)))))
(if (not (null? image))
(begin (write-row (car image)) (write-image (cdr image)))))
(with-output-to-file file
(lambda ()
(begin (display "P6")
(newline)
(display (length (car image)))
(display " ")
(display (length image))
(newline)
(display 255)
(newline)
(write-image image)))))