itch.io

In Lisp I use with-event-loop from cl-sdl2, like this:

(with-event-loop (:method :poll)
              (:keydown
               (:keysym keysym)
               (let ((scancode (scancode-value keysym)))
                 (cond ((scancode= scancode :scancode-space)
                        (format t "Playing Song~%")
                        (sdl2-mixer:play-music music 1))
                       ((scancode= scancode :scancode-up)
                        (when (< (+ *current-volume* 20) 128)
                          (incf *current-volume* 20)
                          (format t "Current Volume: ~a~%" *current-volume*)
                          (sdl2-mixer:volume-music *current-volume*)))
                       ((scancode= scancode :scancode-down)
                        (when (> (- *current-volume* 20) 0)
                          (decf *current-volume* 20)
                          (format t "Current Volume: ~a~%" *current-volume*)
                          (sdl2-mixer:volume-music *current-volume*))))))
......

I think the above code is just like some of your code here :

for (;;) {"
    "
    while(SDL_PollEvent(&e))
        if (e.type == SDL_QUIT) quitted = 1;
        else if (e.type == SDL_KEYDOWN)
            switch (e.key.keysym.sym) {
            case SDLK_q:
                quitted = 1;
                break;
            }

I didn't handle the "holding down" action specifically, so I haven't used something like SDL_GetKeyboardState.

If I were going to do it, I could use the function `keyboard-state-p` as defined here:

(defun keyboard-state-p (scancode)
  "Whether the key corresponding to the given scancode is currently pressed."
  (let ((state (nth-value 1 (autowrap:inhibit-string-conversion
                              (sdl2-ffi.functions:sdl-get-keyboard-state nil))))
        (scancode-num (autowrap:enum-value 'sdl2-ffi:sdl-scancode scancode)))
    (c-let ((state :unsigned-char :ptr state))
      (= (state scancode-num) 1))))

I can see that you're using ECL SFFI in your code, which involves writing C in Lisp, why not using UFFI or CFFI, since it will give us a more Lispy programming experience? Just being curious, because I feel C is too intimidating to me.