add screwdriver plugin

The screwdriver plugin is activated once a configurable button on the
wiimote (B by default) is pressed and held. Turning the wiimote
generates key events as long as the button is held down and the wiimote
is being turned. The threshold for indicating a new event is
configurable. The movement resembles the use of a screwdriver and can be
for example be used to regulate the volume of a media player system,
which feels natural and intuitive.

wminput/configs/screwdriver

@@ -0,0 +1,7 @@
+# screwdriver
+Plugin.screwdriver.Right = KEY_VOLUMEUP
+Plugin.screwdriver.Left = KEY_VOLUMEDOWN
+Plugin.screwdriver.Up = KEY_FASTFORWARD
+Plugin.screwdriver.Down = KEY_REWIND
+Plugin.screwdriver.RollThreshold = 0.19
+Plugin.screwdriver.PitchThreshold = 0.19

wminput/plugins/Makefile.in

@@ -2,7 +2,7 @@
 
 include @top_builddir@/defs.mak
 
-PLUGINS = ir_ptr acc nunchuk_acc led nunchuk_stick2btn
+PLUGINS = ir_ptr acc nunchuk_acc led nunchuk_stick2btn screwdriver
 
 all install clean distclean uninstall: TARGET += $(MAKECMDGOALS)
 

wminput/plugins/screwdriver/Makefile.in

@@ -0,0 +1,14 @@
+include @top_builddir@/defs.mak
+
+PLUGIN_NAME = screwdriver
+SOURCES = screwdriver.c
+CFLAGS += -I@top_builddir@/wminput -I@top_builddir@/libcwiid
+LDLIBS += -lm
+INST_DIR = $(CWIID_PLUGINS_DIR)
+
+include $(COMMON)/include/plugin.mak
+
+distclean: clean
+	rm Makefile
+
+.PHONY: distclean

wminput/plugins/screwdriver/screwdriver.c

@@ -0,0 +1,165 @@
+/* Copyright (C) 2010 Stefan Tomanek <stefan@pico.ruhr.de>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include <math.h>
+
+#include "wmplugin.h"
+
+#define SCREWDRIVER_RIGHT 0x0001
+#define SCREWDRIVER_LEFT  0x0002
+#define SCREWDRIVER_UP    0x0004
+#define SCREWDRIVER_DOWN  0x0008
+
+#define PI	3.14159265358979323
+
+static unsigned char info_init = 0;
+static struct wmplugin_info info;
+static struct wmplugin_data data;
+
+static struct acc_cal acc_cal;
+
+static int plugin_id;
+
+wmplugin_info_t wmplugin_info;
+wmplugin_init_t wmplugin_init;
+wmplugin_exec_t wmplugin_exec;
+static void process_btn(struct cwiid_btn_mesg *mesg);
+static void process_acc(struct cwiid_acc_mesg *mesg);
+
+static int btn_active = 0;
+static uint8_t btn_id = CWIID_BTN_B;
+
+static double last_roll = 0.0;
+static double last_pitch = 0.0;
+static float roll_threshold = 0.25;
+static float pitch_threshold = 0.25;
+
+struct wmplugin_info *wmplugin_info() {
+	if (!info_init) {
+		info.button_count = 4;
+		info.button_info[0].name = "Right";
+		info.button_info[1].name = "Left";
+		info.button_info[2].name = "Up";
+		info.button_info[3].name = "Down";
+		info.param_count = 3;
+		info.param_info[0].name = "Button";
+		info.param_info[0].type = WMPLUGIN_PARAM_INT;
+		info.param_info[0].ptr = &btn_id;
+		info.param_info[1].name = "RollThreshold";
+		info.param_info[1].type = WMPLUGIN_PARAM_FLOAT;
+		info.param_info[1].ptr = &roll_threshold;
+		info.param_info[2].name = "PitchThreshold";
+		info.param_info[2].type = WMPLUGIN_PARAM_FLOAT;
+		info.param_info[2].ptr = &pitch_threshold;
+		info_init = 1;
+	}
+	return &info;
+}
+
+int wmplugin_init(int id, cwiid_wiimote_t *wiimote)
+{
+	plugin_id = id;
+
+	data.buttons = 0;
+	if (wmplugin_set_rpt_mode(id, CWIID_RPT_ACC | CWIID_RPT_BTN)) {
+		return -1;
+	}
+
+	if (cwiid_get_acc_cal(wiimote, CWIID_EXT_NONE, &acc_cal)) {
+		wmplugin_err(id, "calibration error");
+		return -1;
+	}
+
+	return 0;
+}
+
+struct wmplugin_data *wmplugin_exec(int mesg_count, union cwiid_mesg mesg[])
+{
+	int i;
+	struct wmplugin_data *ret = NULL;
+
+	for (i=0; i < mesg_count; i++) {
+		switch (mesg[i].type) {
+		case CWIID_MESG_BTN:
+			process_btn(&mesg[i].btn_mesg);
+			break;
+		case CWIID_MESG_ACC:
+			process_acc(&mesg[i].acc_mesg);
+			ret = &data;
+			break;
+		default:
+			break;
+		}
+	}
+
+	return ret;
+}
+
+#define NEW_AMOUNT 0.1
+#define OLD_AMOUNT (1.0-NEW_AMOUNT)
+double a_x = 0, a_y = 0, a_z = 0;
+
+static void process_btn(struct cwiid_btn_mesg *mesg)
+{
+	btn_active = (mesg->buttons & btn_id);
+}
+
+static void process_acc(struct cwiid_acc_mesg *mesg)
+{
+	double a;
+	double roll, pitch;
+	double d_roll, d_pitch;
+
+	data.buttons = 0;
+
+	a_x = (((double)mesg->acc[CWIID_X] - acc_cal.zero[CWIID_X]) /
+	      (acc_cal.one[CWIID_X] - acc_cal.zero[CWIID_X]))*NEW_AMOUNT +
+	      a_x*OLD_AMOUNT;
+	a_y = (((double)mesg->acc[CWIID_Y] - acc_cal.zero[CWIID_Y]) /
+	      (acc_cal.one[CWIID_Y] - acc_cal.zero[CWIID_Y]))*NEW_AMOUNT +
+	      a_y*OLD_AMOUNT;
+	a_z = (((double)mesg->acc[CWIID_Z] - acc_cal.zero[CWIID_Z]) /
+	      (acc_cal.one[CWIID_Z] - acc_cal.zero[CWIID_Z]))*NEW_AMOUNT +
+	      a_z*OLD_AMOUNT;
+
+	a = sqrt(pow(a_x,2)+pow(a_y,2)+pow(a_z,2));
+	roll = atan(a_x/a_z);
+	pitch = atan(a_y/a_z*cos(roll));
+
+	if (a_z <= 0.0) {
+		roll += PI * ((a_x > 0.0) ? 1 : -1);
+	}
+
+	if (!btn_active) {
+		last_roll = roll;
+		last_pitch = pitch;
+	} else {
+		d_roll = roll - last_roll;
+		if ( fabs(d_roll) > roll_threshold ) {
+			last_roll = roll;
+			data.buttons |= ( (d_roll>0)? SCREWDRIVER_RIGHT : SCREWDRIVER_LEFT );
+		}
+
+		d_pitch = pitch - last_pitch;
+		if ( fabs(d_pitch) > pitch_threshold ) {
+			last_pitch = pitch;
+			data.buttons |= ( (d_pitch>0)? SCREWDRIVER_UP : SCREWDRIVER_DOWN );
+		}
+	}
+}
+