dc example

gistfile1.txt

#lang racket
(require racket/draw)

;; draw-rectangle: dc -> void
(define (draw-rectangle dc)
  (send dc set-brush "green" 'solid)
  (send dc set-pen "blue" 1 'solid)
  (send dc draw-rectangle 0 10 30 10)
  (send dc set-pen "red" 3 'solid)
  (send dc draw-line 0 0 30 30)
  (send dc draw-line 0 30 30 0))

;; as-bitmap: -> bitmap
(define (as-bitmap)
  (define bm (make-bitmap 30 30))
  (define dc (send bm make-dc))
  (draw-rectangle dc)
  bm)

;; as-svg: -> bytes
(define (as-svg)
  (define op (open-output-bytes))
  (define dc (new svg-dc%
                  [width 30]
                  [height 30]
                  [output op]))
  (send dc start-doc "test")
  (send dc start-page)
  (draw-rectangle dc)
  (send dc end-page)
  (send dc end-doc)
  (get-output-bytes op))