;;; Beta quality code - use at own risk

;;; Copyright (C) 2010 Anders Waldenborg
;;; I'll add a GPL header or something like that here later...

;;; Small example on how to use vrend.

;;; Defines the command vrend-clock which creates a new buffer,
;;; Make sure you resize the window/frame and stuff like that.

(require 'cl)
(require 'vrend)

(defun vrend-clock-update-buffer (buf)
  (let ((win (get-buffer-window buf t)))
    (when win
      (let* ((X (window-inside-pixel-edges win))
	     (w (- (car (cddr X)) (car X)))
	     (h (- (cadr (cddr X)) (cadr X))))
	(with-current-buffer buf
	  (erase-buffer)
	  (insert-image (vrend w h '1x1fit

			  ;; Make hour markers...
			  (vrend-path-start 0.0 0.8)
			  (vrend-path-lineto 0.0 0.9)
			  (vrend-path-close)

			  ;; ...12 of them
			  (loop for D from 0 to 11 by 1
				do (vrend-with-saved-matrix
				     (vrend-rotate (* D (/ vrend-2pi 12)))
				     (vrend-path-stroke)))

			  ;; and arrows
			  (let* ((ct (current-time))
				 (T (decode-time ct))
				 (h (nth 2 T))
				 (m (nth 1 T))
				 (s (nth 0 T))
				 (ms (/ (nth 2 ct) 1000))
				 (seconds-since-midnight (+ (* (+ (* h 60) m) 60) s))
				 (seconds-since-hour (+ (* m 60) s))
				 (ms-since-minute (+ ms (* s 1000))))
			    (vrend-with-saved-matrix
			      (vrend-path-start 0.0 0.0)
			      (vrend-path-lineto -0.05 0.4)
			      (vrend-path-lineto 0.0 0.6)
			      (vrend-path-lineto 0.05 0.4)
			      (vrend-path-close)
			      (vrend-rotate (* seconds-since-midnight (/ vrend-2pi (* 60 60 12))))
			      (vrend-path-stroke))
			    (vrend-with-saved-matrix
			      (vrend-path-start 0.0 0.0)
			      (vrend-path-lineto -0.05 0.3)
			      (vrend-path-lineto 0.0 0.90)
			      (vrend-path-lineto 0.05 0.3)
			      (vrend-path-close)
			      (vrend-rotate (* seconds-since-hour (/ vrend-2pi (* 60 60))))
			      (vrend-path-stroke))
			    (vrend-with-saved-matrix
			      (vrend-path-start 0.0 0.0)
			      (vrend-path-lineto 0.0 0.90)
			      (vrend-path-close)
			      (vrend-rotate (* ms-since-minute (/ vrend-2pi 60000.0)))
			      (vrend-path-stroke))))))))))

(defun vrend-kill-buffer-hook ()
  (cancel-timer vrend-clock-timer))

(defun vrend-clock ()
  (interactive)
  (with-current-buffer (generate-new-buffer "*aw-clock*")
    (set-window-buffer nil (current-buffer))
    (make-local-variable 'vrend-clock-timer)
    (add-hook 'kill-buffer-hook 'vrend-kill-buffer-hook nil t)

    (setq vrend-clock-timer (run-at-time nil 0.1 'vrend-clock-update-buffer (current-buffer)))))