File canvas-draw/racket/play.rkt artifact 799196508d part of check-in bc89e96dce

#lang racket
(require
 ffi/unsafe
 "base.rkt")

(define libcd
  (case (system-type 'os)
    [(windows)
     (ffi-lib "cd")]
    [else
     (ffi-lib "libcd")]))

;; {{{ Context content playback

(define canvas-play/ptr!
  (get-ffi-obj
   "cdCanvasPlay" libcd
   (_fun [canvas : _canvas] [context : _context]
         [x0 : _int] [x1 : _int] [y0 : _int] [y1 : _int]
         [data : _pointer]
         -> [rc : _int])))

(define canvas-play/string!
  (get-ffi-obj
   "cdCanvasPlay" libcd
   (_fun [canvas : _canvas] [context : _context]
         [x0 : _int] [x1 : _int] [y0 : _int] [y1 : _int]
         [data : _string/utf-8]
         -> [rc : _int])))

(define (canvas-play! canvas context x0 x1 y0 y1 data)
  (let ([canvas-play/data! (if (string? data) canvas-play/string! canvas-play/ptr!)])
    (unless (zero? (canvas-play/data! canvas context x0 x1 y0 y1 data))
      (error 'canvas-play! "failed to replay graphics"))))

(provide
 canvas-play!)

;; }}}