;; this file:
;;   https://dataswamp.org/~incal/common-lisp/2d-demo/2d-demo.lisp
;;
;; compile:
;;   CL-USER> (asdf:clear-configuration)
;;   CL-USER> (asdf:load-system "2d-demo")

(require :rect)
(require :sdl2)

(defun clear (rend &optional (r 0) (g 0) (b 0) (a 255))
  (sdl2:set-render-draw-color rend r g b a)
  (sdl2:render-clear rend) )

(defun delay (&optional (plen 33))
  (when (< 0 plen)
    (sdl2:delay plen) ))

(defun 2d-demo ()
  (sdl2:with-init (:everything)
    (sdl2:with-window (win :title "SBCL/SDL2 demo" :flags '(:shown))
      (sdl2:with-renderer (rend win :flags '(:accelerated))
        (let ((draw t))
          (sdl2:with-event-loop (:method :poll)
            (:keydown
              (:keysym ks)
              (let ((scv  (sdl2:scancode-value ks))
                    (symv (sdl2:sym-value ks))
                    (modv (sdl2:mod-value ks)) )
                (cond
                  ((sdl2:scancode= scv :scancode-p) ;; [P] draw
                   (setf draw (not draw)))
                  ((sdl2:scancode= scv :scancode-q) ;; [Q] quit
                   (sdl2:push-event :quit)) )
                (format t "key: ~a ~a ~a~%" scv symv modv) ))
            (:idle ()
              (when draw
                (clear rend)
                (draw-rect rend 100 100 200 200 0 255 0)
                (tile rend 1 1)
                (sdl2:render-present rend) )
              (delay) )
            (:quit () t) ))))))

(provide :2d-demo)