elk/examples/xlib/poly.scm

36 lines
977 B
Scheme

;;; -*-Scheme-*-
(require 'xlib)
(define (poly)
(let* ((dpy (open-display))
(black (black-pixel dpy)) (white (white-pixel dpy))
(width 400) (height 400)
(win (create-window 'parent (display-root-window dpy)
'width width 'height height
'background-pixel white 'event-mask '(exposure)))
(gc (create-gcontext 'window win 'function 'xor
'background white 'foreground black))
(l '(#f #f #f))
(rand (lambda (x) (modulo (random) x))))
(map-window win)
(handle-events dpy #t #f
(else (lambda args
(set! width (window-width win))
(set! height (window-height win)) #t)))
(unwind-protect
(let loop ((n 0))
(if (= n 200)
(begin
(clear-window win)
(display-wait-output dpy #f)
(set! n 0)))
(fill-polygon win gc
(list->vector
(map (lambda (x) (cons (rand width) (rand height))) l))
#f 'convex)
(loop (1+ n)))
(close-display dpy))))
(poly)