Final merge of Google Summer of Code 2008 work...

Force Feedback for SDL
by Edgar Simo, mentored by Ryan C. Gordon

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%403159

src/joystick/linux/SDL_sysjoystick_c.h

@@ -0,0 +1,55 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997-2006 Sam Lantinga
+
+    This library 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 2.1 of the License, or (at your option) any later version.
+
+    This library 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
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+    Sam Lantinga
+    slouken@libsdl.org
+*/
+
+#if SDL_INPUT_LINUXEV
+#include <linux/input.h>
+#endif
+
+/* The private structure used to keep track of a joystick */
+struct joystick_hwdata
+{
+    int fd;
+    char *fname;                /* Used in haptic subsystem */
+
+    /* The current linux joystick driver maps hats to two axes */
+    struct hwdata_hat
+    {
+        int axis[2];
+    } *hats;
+    /* The current linux joystick driver maps balls to two axes */
+    struct hwdata_ball
+    {
+        int axis[2];
+    } *balls;
+
+    /* Support for the Linux 2.4 unified input interface */
+#if SDL_INPUT_LINUXEV
+    SDL_bool is_hid;
+    Uint8 key_map[KEY_MAX - BTN_MISC];
+    Uint8 abs_map[ABS_MAX];
+    struct axis_correct
+    {
+        int used;
+        int coef[3];
+    } abs_correct[ABS_MAX];
+#endif
+};