From 55c854fc3016b4a3e9328c7c97495d5f3d770e28 Mon Sep 17 00:00:00 2001
From: David Thompson <dthompson2@worcester.edu>
Date: Fri, 10 Nov 2017 21:23:58 -0500
Subject: Add mouse input module.

* sdl2/input/mouse.scm: New file.
* Makefile.am (SOURCES): Add it.
---
 Makefile.am          |  1 +
 sdl2/input/mouse.scm | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)
 create mode 100644 sdl2/input/mouse.scm

diff --git a/Makefile.am b/Makefile.am
index 7325bee..1d504f5 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -52,6 +52,7 @@ SOURCES =					\
   sdl2/input/keyboard.scm			\
   sdl2/input/joystick.scm			\
   sdl2/input/game-controller.scm		\
+  sdl2/input/mouse.scm				\
   sdl2/input/text.scm
 
 if WITH_LIBSDL2_IMAGE
diff --git a/sdl2/input/mouse.scm b/sdl2/input/mouse.scm
new file mode 100644
index 0000000..55c7833
--- /dev/null
+++ b/sdl2/input/mouse.scm
@@ -0,0 +1,67 @@
+;;; 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:
+;;
+;; Mouse input.
+;;
+;;; Code:
+
+(define-module (sdl2 input mouse)
+  #:use-module (ice-9 match)
+  #:use-module (rnrs bytevectors)
+  #:use-module (sdl2)
+  #:use-module ((sdl2 bindings) #:prefix ffi:)
+  #:use-module (system foreign)
+  #:export (mouse-x
+            mouse-y
+            mouse-button-pressed?))
+
+(define (make-int)
+  (make-bytevector (sizeof int)))
+
+(define (get-int bv)
+  (bytevector-sint-ref bv 0 (native-endianness) (sizeof int)))
+
+(define mouse-x
+  (let* ((bv (make-int))
+         (ptr (bytevector->pointer bv)))
+    (lambda ()
+      "Return the x coordinate of the mouse cursor."
+      (ffi:sdl-get-mouse-state ptr %null-pointer)
+      (get-int bv))))
+
+(define mouse-y
+  (let* ((bv (make-int))
+         (ptr (bytevector->pointer bv)))
+    (lambda ()
+      "Return the y coordinate of the mouse cursor."
+      (ffi:sdl-get-mouse-state %null-pointer ptr)
+      (get-int bv))))
+
+(define (mouse-button-pressed? button)
+  "Return #t if BUTTON is currently being pressed."
+  (let ((mask (match button
+                ('left ffi:SDL_BUTTON_LMASK)
+                ('middle ffi:SDL_BUTTON_MMASK)
+                ('right ffi:SDL_BUTTON_RMASK)
+                ('x1 ffi:SDL_BUTTON_X1MASK)
+                ('x2 ffi:SDL_BUTTON_X2MASK)))
+        (buttons (ffi:sdl-get-mouse-state %null-pointer %null-pointer)))
+    (> (logand mask buttons) 0)))
-- 
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