test.lsp

(ql:quickload :sdl2)
(require :sdl2)
(require :cl-opengl)

(defun render ()
  "drawing whatever happens in a frame"
  (gl:clear :color-buffer)
  (gl:begin :triangles)
  (gl:color 0.0 1.0 0.0)
  (gl:vertex 0.0 1.0)
  (gl:vertex -1.0 -1.0)
  (gl:vertex 1.0 -1.0)
  (gl:end)
  (gl:flush)
  )

(defun my-test ()
  "just rendering basic stuff"
  (sdl2:with-init (:everything)
    (sdl2:with-window (win :flags '(:shown :opengl))
      (sdl2:with-gl-context (gl-context win)
        (let ()
          (sdl2:gl-make-current win gl-context)
          (gl:viewport 0 0 800 600)
          (gl:matrix-mode :projection)
          (gl:ortho -2 2 -2 2 -2 2)
          (gl:matrix-mode :modelview)
          (gl:load-identity)
          (gl:clear-color 0.0 0.0 1.0 1.0)
          (gl:clear :color-buffer)

          ;; main loop
          (format t "Beginning main loop.~%")
          (finish-output)

          (sdl2:with-event-loop (:method :poll)
            (:keyup (:keysym keysym)
                    (when (sdl2:scancode= (sdl2:scancode-value keysym) :scancode-escape)
                      (sdl2:push-event :quit)))

            (:idle ()
                   (render)
                   (sdl2:gl-swap-window win))
            
            (:quit () t))

          )))))

(defun start()
  (bt:make-thread (lambda () (my-test))))