;; Input handling and helpers

; button values defined in Chicken SDL; one of SDL_BUTTON_LMASK,
; SDL_BUTTON_MMASK, SDL_BUTTON_RMASK or a usage of the function
; (SDL_BUTTON <sdl button constant>)
;
; The state comes from the mouse event.

(define (mousebutton-down?/state button state)
  (> (bitwise-and state button) 0))

(define (mousebutton-down? button)
  (mousebutton-down?/state (sdl-get-mouse-state 0 0) button))

(define (mouse-position)
  (let ((x (s32vector 0))
        (y (s32vector 0)))
    (sdl-get-mouse-state x y)
    (make-point2d (s32vector-ref x 0) (s32vector-ref y 0))))

; modifier values defined in Chicken SDL; one of KMOD_CTRL,
; KMOD_SHIFT, KMOD_ALT, KMOD_META or the more specific variants with
; 'L' or 'R' for left or right e.g., KMOD_LSHIFT.

(define (modifier-down?/state modifier state)
  (> (bitwise-and modifier state) 0))

(define (modifier-down? modifier)
  (modifier-down?/state modifier (sdl-get-mod-state)))