zsnes-dualshock3-buttons.scm

   1 ;;; Calculate ZSNES buttons for Dualshock controllers
   2
   3 ;; From: http://blog.brokenfunction.com/2009/07/zsnes-and-a-sixaxis-controller/#comment-56667
   4 ;; Run zsnes and quit.
   5 ;; Look for the lines (something like)
   6 ;; Device 0 Sony PLAYSTATION(R)3 Controller
   7 ;; 27 axis, 19 buttons, 0 hats, 0 balls
   8 ;; Device 1 Sony PLAYSTATION(R)3 Controller
   9 ;; 27 axis, 19 buttons, 0 hats, 0 balls
  10
  11 ;; Note the number of axes and buttons for controller 1 (first) and second (2).
  12 ;; e.g. axes1, buttons1, axes2, buttons2
  13
  14 ;; Controller 1′s select button (base) will be 256 + (axes1*2)
  15
  16 ;; Controller 2′s select button (base) will be 256 + (axes1*2) + buttons1 + (axes2*2)
  17 ;; Equivalently, it’s Controller 1′s base + buttons1 + (axes2*2)
  18
  19 ;; Unfortunately, you can’t use 3 controllers this way, because it has
  20 ;; a hardcoded max offset of 448 (not sure why). It would have to be
  21 ;; recompiled at least to get around this but that might be based on a
  22 ;; dependency.
  23
  24 ;; You can see the logic for this in zsnes’s source code, in src/linux/sdllink.c in
  25 ;; BOOL InitJoystickInput(void){}
  26
  27 (define axis-count 29)
  28 (define button-count 17)
  29
  30 (define (base-button) (+ 256 (* 2 axis-count)))
  31
  32 (define (base-button-2)
  33   (+ (base-button) button-count (* 2 axis-count)))
  34
  35 (define (zsnes-buttons js-button)
  36   (values (+ (base-button) js-button)
  37           (+ (base-button-2) js-button)))