input: Add keyboard module.

* sdl2/bindings.scm (sdl-get-keyboard-state): New procedure.
* sdl2/input/keyboard.scm: New file.
* Makefile.am (SOURCES): Add it.

2 files changed, 292 insertions, 0 deletions

diff --git a/sdl2/bindings.scm b/sdl2/bindings.scm
index 1eb4813..d69e737 100644
--- a/sdl2/bindings.scm
+++ b/sdl2/bindings.scm
@@ -816,6 +816,9 @@ RETURN-TYPE and accept arguments of ARG-TYPES."
 (define-public SDLK_EJECT (scancode->keycode SDL_SCANCODE_EJECT))
 (define-public SDLK_SLEEP (scancode->keycode SDL_SCANCODE_SLEEP))
 
+(define-foreign sdl-get-keyboard-state
+  '* "SDL_GetKeyboardState" '(*))
+
 
 ;;;
 ;;; Text Input
diff --git a/sdl2/input/keyboard.scm b/sdl2/input/keyboard.scm
new file mode 100644
index 0000000..0d25290
--- /dev/null
+++ b/sdl2/input/keyboard.scm
@@ -0,0 +1,289 @@
+;;; guile-sdl2 --- FFI bindings for SDL2
+;;; Copyright © 2017 David Thompson <davet@gnu.org>
+;;;
+;;; This file is part of guile-sdl2.
+;;;
+;;; Guile-sdl2 is free software; you can redistribute it and/or modify
+;;; it under the terms of the GNU Lesser General Public License as
+;;; published by the Free Software Foundation; either version 3 of the
+;;; License, or (at your option) any later version.
+;;;
+;;; Guile-sdl2 is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;;; General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU Lesser General Public
+;;; License along with guile-sdl2.  If not, see
+;;; <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+;; Keyboard input.
+;;
+;;; Code:
+
+(define-module (sdl2 input keyboard)
+  #:use-module (ice-9 hash-table)
+  #:use-module (ice-9 match)
+  #:use-module (srfi srfi-4)
+  #:use-module (system foreign)
+  #:use-module ((sdl2 bindings) #:prefix ffi:)
+  #:export (key-pressed?
+            key-released?))
+
+(define scancode-map
+  (alist->hashq-table
+   `((unknown . ,ffi:SDL_SCANCODE_UNKNOWN)
+     (a . ,ffi:SDL_SCANCODE_A)
+     (b . ,ffi:SDL_SCANCODE_B)
+     (c . ,ffi:SDL_SCANCODE_C)
+     (d . ,ffi:SDL_SCANCODE_D)
+     (e . ,ffi:SDL_SCANCODE_E)
+     (f . ,ffi:SDL_SCANCODE_F)
+     (g . ,ffi:SDL_SCANCODE_G)
+     (h . ,ffi:SDL_SCANCODE_H)
+     (i . ,ffi:SDL_SCANCODE_I)
+     (j . ,ffi:SDL_SCANCODE_J)
+     (k . ,ffi:SDL_SCANCODE_K)
+     (l . ,ffi:SDL_SCANCODE_L)
+     (m . ,ffi:SDL_SCANCODE_M)
+     (n . ,ffi:SDL_SCANCODE_N)
+     (o . ,ffi:SDL_SCANCODE_O)
+     (p . ,ffi:SDL_SCANCODE_P)
+     (q . ,ffi:SDL_SCANCODE_Q)
+     (r . ,ffi:SDL_SCANCODE_R)
+     (s . ,ffi:SDL_SCANCODE_S)
+     (t . ,ffi:SDL_SCANCODE_T)
+     (u . ,ffi:SDL_SCANCODE_U)
+     (v . ,ffi:SDL_SCANCODE_V)
+     (w . ,ffi:SDL_SCANCODE_W)
+     (x . ,ffi:SDL_SCANCODE_X)
+     (y . ,ffi:SDL_SCANCODE_Y)
+     (z . ,ffi:SDL_SCANCODE_Z)
+     (1 . ,ffi:SDL_SCANCODE_1)
+     (2 . ,ffi:SDL_SCANCODE_2)
+     (3 . ,ffi:SDL_SCANCODE_3)
+     (4 . ,ffi:SDL_SCANCODE_4)
+     (5 . ,ffi:SDL_SCANCODE_5)
+     (6 . ,ffi:SDL_SCANCODE_6)
+     (7 . ,ffi:SDL_SCANCODE_7)
+     (8 . ,ffi:SDL_SCANCODE_8)
+     (9 . ,ffi:SDL_SCANCODE_9)
+     (0 . ,ffi:SDL_SCANCODE_0)
+     (return . ,ffi:SDL_SCANCODE_RETURN)
+     (escape . ,ffi:SDL_SCANCODE_ESCAPE)
+     (backspace . ,ffi:SDL_SCANCODE_BACKSPACE)
+     (tab . ,ffi:SDL_SCANCODE_TAB)
+     (space . ,ffi:SDL_SCANCODE_SPACE)
+     (minus . ,ffi:SDL_SCANCODE_MINUS)
+     (equals . ,ffi:SDL_SCANCODE_EQUALS)
+     (left-bracket . ,ffi:SDL_SCANCODE_LEFTBRACKET)
+     (right-bracket . ,ffi:SDL_SCANCODE_RIGHTBRACKET)
+     (backslash . ,ffi:SDL_SCANCODE_BACKSLASH)
+     (nonushash . ,ffi:SDL_SCANCODE_NONUSHASH)
+     (semicolon . ,ffi:SDL_SCANCODE_SEMICOLON)
+     (apostrophe . ,ffi:SDL_SCANCODE_APOSTROPHE)
+     (grave . ,ffi:SDL_SCANCODE_GRAVE)
+     (comma . ,ffi:SDL_SCANCODE_COMMA)
+     (period . ,ffi:SDL_SCANCODE_PERIOD)
+     (slash . ,ffi:SDL_SCANCODE_SLASH)
+     (caps-lock . ,ffi:SDL_SCANCODE_CAPSLOCK)
+     (f1 . ,ffi:SDL_SCANCODE_F1)
+     (f2 . ,ffi:SDL_SCANCODE_F2)
+     (f3 . ,ffi:SDL_SCANCODE_F3)
+     (f4 . ,ffi:SDL_SCANCODE_F4)
+     (f5 . ,ffi:SDL_SCANCODE_F5)
+     (f6 . ,ffi:SDL_SCANCODE_F6)
+     (f7 . ,ffi:SDL_SCANCODE_F7)
+     (f8 . ,ffi:SDL_SCANCODE_F8)
+     (f9 . ,ffi:SDL_SCANCODE_F9)
+     (f10 . ,ffi:SDL_SCANCODE_F10)
+     (f11 . ,ffi:SDL_SCANCODE_F11)
+     (f12 . ,ffi:SDL_SCANCODE_F12)
+     (print-screen . ,ffi:SDL_SCANCODE_PRINTSCREEN)
+     (scroll-lock . ,ffi:SDL_SCANCODE_SCROLLLOCK)
+     (pause . ,ffi:SDL_SCANCODE_PAUSE)
+     (insert . ,ffi:SDL_SCANCODE_INSERT)
+     (home . ,ffi:SDL_SCANCODE_HOME)
+     (page-up . ,ffi:SDL_SCANCODE_PAGEUP)
+     (delete . ,ffi:SDL_SCANCODE_DELETE)
+     (end . ,ffi:SDL_SCANCODE_END)
+     (page-down . ,ffi:SDL_SCANCODE_PAGEDOWN)
+     (right . ,ffi:SDL_SCANCODE_RIGHT)
+     (left . ,ffi:SDL_SCANCODE_LEFT)
+     (down . ,ffi:SDL_SCANCODE_DOWN)
+     (up . ,ffi:SDL_SCANCODE_UP)
+     (num-lock-clear . ,ffi:SDL_SCANCODE_NUMLOCKCLEAR)
+     (keypad-divide . ,ffi:SDL_SCANCODE_KP_DIVIDE)
+     (keypad-multiply . ,ffi:SDL_SCANCODE_KP_MULTIPLY)
+     (keypad-minus . ,ffi:SDL_SCANCODE_KP_MINUS)
+     (keypad-plus . ,ffi:SDL_SCANCODE_KP_PLUS)
+     (keypad-enter . ,ffi:SDL_SCANCODE_KP_ENTER)
+     (keypad-1 . ,ffi:SDL_SCANCODE_KP_1)
+     (keypad-2 . ,ffi:SDL_SCANCODE_KP_2)
+     (keypad-3 . ,ffi:SDL_SCANCODE_KP_3)
+     (keypad-4 . ,ffi:SDL_SCANCODE_KP_4)
+     (keypad-5 . ,ffi:SDL_SCANCODE_KP_5)
+     (keypad-6 . ,ffi:SDL_SCANCODE_KP_6)
+     (keypad-7 . ,ffi:SDL_SCANCODE_KP_7)
+     (keypad-8 . ,ffi:SDL_SCANCODE_KP_8)
+     (keypad-9 . ,ffi:SDL_SCANCODE_KP_9)
+     (keypad-0 . ,ffi:SDL_SCANCODE_KP_0)
+     (keypad-period . ,ffi:SDL_SCANCODE_KP_PERIOD)
+     (nonusbackslash . ,ffi:SDL_SCANCODE_NONUSBACKSLASH)
+     (application . ,ffi:SDL_SCANCODE_APPLICATION)
+     (power . ,ffi:SDL_SCANCODE_POWER)
+     (keypad-equals . ,ffi:SDL_SCANCODE_KP_EQUALS)
+     (f13 . ,ffi:SDL_SCANCODE_F13)
+     (f14 . ,ffi:SDL_SCANCODE_F14)
+     (f15 . ,ffi:SDL_SCANCODE_F15)
+     (f16 . ,ffi:SDL_SCANCODE_F16)
+     (f17 . ,ffi:SDL_SCANCODE_F17)
+     (f18 . ,ffi:SDL_SCANCODE_F18)
+     (f19 . ,ffi:SDL_SCANCODE_F19)
+     (f20 . ,ffi:SDL_SCANCODE_F20)
+     (f21 . ,ffi:SDL_SCANCODE_F21)
+     (f22 . ,ffi:SDL_SCANCODE_F22)
+     (f23 . ,ffi:SDL_SCANCODE_F23)
+     (f24 . ,ffi:SDL_SCANCODE_F24)
+     (execute . ,ffi:SDL_SCANCODE_EXECUTE)
+     (help . ,ffi:SDL_SCANCODE_HELP)
+     (menu . ,ffi:SDL_SCANCODE_MENU)
+     (select . ,ffi:SDL_SCANCODE_SELECT)
+     (stop . ,ffi:SDL_SCANCODE_STOP)
+     (again . ,ffi:SDL_SCANCODE_AGAIN)
+     (undo . ,ffi:SDL_SCANCODE_UNDO)
+     (cut . ,ffi:SDL_SCANCODE_CUT)
+     (copy . ,ffi:SDL_SCANCODE_COPY)
+     (paste . ,ffi:SDL_SCANCODE_PASTE)
+     (find . ,ffi:SDL_SCANCODE_FIND)
+     (mute . ,ffi:SDL_SCANCODE_MUTE)
+     (volume-up . ,ffi:SDL_SCANCODE_VOLUMEUP)
+     (volume-down . ,ffi:SDL_SCANCODE_VOLUMEDOWN)
+     (keypad-comma . ,ffi:SDL_SCANCODE_KP_COMMA)
+     (keypad-equalsas400 . ,ffi:SDL_SCANCODE_KP_EQUALSAS400)
+     (international-1 . ,ffi:SDL_SCANCODE_INTERNATIONAL1)
+     (international-2 . ,ffi:SDL_SCANCODE_INTERNATIONAL2)
+     (international-3 . ,ffi:SDL_SCANCODE_INTERNATIONAL3)
+     (international-4 . ,ffi:SDL_SCANCODE_INTERNATIONAL4)
+     (international-5 . ,ffi:SDL_SCANCODE_INTERNATIONAL5)
+     (international-6 . ,ffi:SDL_SCANCODE_INTERNATIONAL6)
+     (international-7 . ,ffi:SDL_SCANCODE_INTERNATIONAL7)
+     (international-8 . ,ffi:SDL_SCANCODE_INTERNATIONAL8)
+     (international-9 . ,ffi:SDL_SCANCODE_INTERNATIONAL9)
+     (lang-1 . ,ffi:SDL_SCANCODE_LANG1)
+     (lang-2 . ,ffi:SDL_SCANCODE_LANG2)
+     (lang-3 . ,ffi:SDL_SCANCODE_LANG3)
+     (lang-4 . ,ffi:SDL_SCANCODE_LANG4)
+     (lang-5 . ,ffi:SDL_SCANCODE_LANG5)
+     (lang-6 . ,ffi:SDL_SCANCODE_LANG6)
+     (lang-7 . ,ffi:SDL_SCANCODE_LANG7)
+     (lang-8 . ,ffi:SDL_SCANCODE_LANG8)
+     (lang-9 . ,ffi:SDL_SCANCODE_LANG9)
+     (alt-erase . ,ffi:SDL_SCANCODE_ALTERASE)
+     (sysreq . ,ffi:SDL_SCANCODE_SYSREQ)
+     (cancel . ,ffi:SDL_SCANCODE_CANCEL)
+     (clear . ,ffi:SDL_SCANCODE_CLEAR)
+     (prior . ,ffi:SDL_SCANCODE_PRIOR)
+     (return-2 . ,ffi:SDL_SCANCODE_RETURN2)
+     (separator . ,ffi:SDL_SCANCODE_SEPARATOR)
+     (out . ,ffi:SDL_SCANCODE_OUT)
+     (oper . ,ffi:SDL_SCANCODE_OPER)
+     (clear-again . ,ffi:SDL_SCANCODE_CLEARAGAIN)
+     (crsel . ,ffi:SDL_SCANCODE_CRSEL)
+     (exsel . ,ffi:SDL_SCANCODE_EXSEL)
+     (keypad-00 . ,ffi:SDL_SCANCODE_KP_00)
+     (keypad-000 . ,ffi:SDL_SCANCODE_KP_000)
+     (thousands-separator . ,ffi:SDL_SCANCODE_THOUSANDSSEPARATOR)
+     (decimal-separator . ,ffi:SDL_SCANCODE_DECIMALSEPARATOR)
+     (currency-unit . ,ffi:SDL_SCANCODE_CURRENCYUNIT)
+     (current-subunit . ,ffi:SDL_SCANCODE_CURRENCYSUBUNIT)
+     (keypad-left-paren . ,ffi:SDL_SCANCODE_KP_LEFTPAREN)
+     (keypad-right-paren . ,ffi:SDL_SCANCODE_KP_RIGHTPAREN)
+     (keypad-left-brace . ,ffi:SDL_SCANCODE_KP_LEFTBRACE)
+     (keypad-right-brace . ,ffi:SDL_SCANCODE_KP_RIGHTBRACE)
+     (keypad-tab . ,ffi:SDL_SCANCODE_KP_TAB)
+     (keypad-backspace . ,ffi:SDL_SCANCODE_KP_BACKSPACE)
+     (keypad-a . ,ffi:SDL_SCANCODE_KP_A)
+     (keypad-b . ,ffi:SDL_SCANCODE_KP_B)
+     (keypad-c . ,ffi:SDL_SCANCODE_KP_C)
+     (keypad-d . ,ffi:SDL_SCANCODE_KP_D)
+     (keypad-e . ,ffi:SDL_SCANCODE_KP_E)
+     (keypad-f . ,ffi:SDL_SCANCODE_KP_F)
+     (keypad-xor . ,ffi:SDL_SCANCODE_KP_XOR)
+     (keypad-power . ,ffi:SDL_SCANCODE_KP_POWER)
+     (keypad-percent . ,ffi:SDL_SCANCODE_KP_PERCENT)
+     (keypad-less . ,ffi:SDL_SCANCODE_KP_LESS)
+     (keypad-greater . ,ffi:SDL_SCANCODE_KP_GREATER)
+     (keypad-ampersand . ,ffi:SDL_SCANCODE_KP_AMPERSAND)
+     (keypad-double-ampersand . ,ffi:SDL_SCANCODE_KP_DBLAMPERSAND)
+     (keypad-vertical-bar . ,ffi:SDL_SCANCODE_KP_VERTICALBAR)
+     (keypad-double-vertical-bar . ,ffi:SDL_SCANCODE_KP_DBLVERTICALBAR)
+     (keypad-colon . ,ffi:SDL_SCANCODE_KP_COLON)
+     (keypad-hash . ,ffi:SDL_SCANCODE_KP_HASH)
+     (keypad-space . ,ffi:SDL_SCANCODE_KP_SPACE)
+     (keypad-at . ,ffi:SDL_SCANCODE_KP_AT)
+     (keypad-exclam . ,ffi:SDL_SCANCODE_KP_EXCLAM)
+     (keypad-mem-store . ,ffi:SDL_SCANCODE_KP_MEMSTORE)
+     (keypad-mem-recall . ,ffi:SDL_SCANCODE_KP_MEMRECALL)
+     (keypad-mem-clear . ,ffi:SDL_SCANCODE_KP_MEMCLEAR)
+     (keypad-mem-add . ,ffi:SDL_SCANCODE_KP_MEMADD)
+     (keypadd-mem-subtract . ,ffi:SDL_SCANCODE_KP_MEMSUBTRACT)
+     (keypad-mem-multiply . ,ffi:SDL_SCANCODE_KP_MEMMULTIPLY)
+     (keypad-mem-divide . ,ffi:SDL_SCANCODE_KP_MEMDIVIDE)
+     (keypad-plus-minus . ,ffi:SDL_SCANCODE_KP_PLUSMINUS)
+     (keypad-clear . ,ffi:SDL_SCANCODE_KP_CLEAR)
+     (keypad-clear-entry . ,ffi:SDL_SCANCODE_KP_CLEARENTRY)
+     (keypad-binary . ,ffi:SDL_SCANCODE_KP_BINARY)
+     (keypad-octal . ,ffi:SDL_SCANCODE_KP_OCTAL)
+     (keypad-decimal . ,ffi:SDL_SCANCODE_KP_DECIMAL)
+     (keypad-hexadecimal . ,ffi:SDL_SCANCODE_KP_HEXADECIMAL)
+     (left-control . ,ffi:SDL_SCANCODE_LCTRL)
+     (left-shift . ,ffi:SDL_SCANCODE_LSHIFT)
+     (left-alt . ,ffi:SDL_SCANCODE_LALT)
+     (left-gui . ,ffi:SDL_SCANCODE_LGUI)
+     (right-control . ,ffi:SDL_SCANCODE_RCTRL)
+     (right-shift . ,ffi:SDL_SCANCODE_RSHIFT)
+     (right-alt . ,ffi:SDL_SCANCODE_RALT)
+     (right-cui . ,ffi:SDL_SCANCODE_RGUI)
+     (mode . ,ffi:SDL_SCANCODE_MODE)
+     (audio-next . ,ffi:SDL_SCANCODE_AUDIONEXT)
+     (audio-prev . ,ffi:SDL_SCANCODE_AUDIOPREV)
+     (audio-stop . ,ffi:SDL_SCANCODE_AUDIOSTOP)
+     (audio-play . ,ffi:SDL_SCANCODE_AUDIOPLAY)
+     (audio-mute . ,ffi:SDL_SCANCODE_AUDIOMUTE)
+     (media-select . ,ffi:SDL_SCANCODE_MEDIASELECT)
+     (www . ,ffi:SDL_SCANCODE_WWW)
+     (mail . ,ffi:SDL_SCANCODE_MAIL)
+     (calculator . ,ffi:SDL_SCANCODE_CALCULATOR)
+     (computer . ,ffi:SDL_SCANCODE_COMPUTER)
+     (ac-search . ,ffi:SDL_SCANCODE_AC_SEARCH)
+     (ac-home . ,ffi:SDL_SCANCODE_AC_HOME)
+     (ac-back . ,ffi:SDL_SCANCODE_AC_BACK)
+     (ac-forward . ,ffi:SDL_SCANCODE_AC_FORWARD)
+     (ac-stop . ,ffi:SDL_SCANCODE_AC_STOP)
+     (ac-refresh . ,ffi:SDL_SCANCODE_AC_REFRESH)
+     (ac-bookmarks . ,ffi:SDL_SCANCODE_AC_BOOKMARKS)
+     (brightness-down . ,ffi:SDL_SCANCODE_BRIGHTNESSDOWN)
+     (brightness-up . ,ffi:SDL_SCANCODE_BRIGHTNESSUP)
+     (display-switch . ,ffi:SDL_SCANCODE_DISPLAYSWITCH)
+     (keyboard-illum-toggle . ,ffi:SDL_SCANCODE_KBDILLUMTOGGLE)
+     (keyboard-illum-down . ,ffi:SDL_SCANCODE_KBDILLUMDOWN)
+     (keyboard-illum-up . ,ffi:SDL_SCANCODE_KBDILLUMUP)
+     (eject . ,ffi:SDL_SCANCODE_EJECT)
+     (sleep . ,ffi:SDL_SCANCODE_SLEEP)
+     (app-1 . ,ffi:SDL_SCANCODE_APP1)
+     (app-2 . ,ffi:SDL_SCANCODE_APP2))))
+
+(define key-pressed?
+  (let ((keystate (pointer->bytevector
+                   (ffi:sdl-get-keyboard-state %null-pointer)
+                   ffi:SDL_NUM_SCANCODES)))
+    (lambda (key)
+      "Return #t if KEY is currently being pressed."
+      (= 1 (u8vector-ref keystate (hashq-ref scancode-map key))))))
+
+(define (key-released? key)
+  "Return #t if KEY is not currently being pressed."
+  (not (key-pressed? key)))