/*****************************************************************************
 *
 * grail - Gesture Recognition And Instantiation Library
 *
 * Copyright (C) 2010 Canonical Ltd.
 * Copyright (C) 2010 Henrik Rydberg <rydberg@bitmath.org>
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 ****************************************************************************/

#include <grail-touch.h>
#include <math.h>

/* see mtdev-mapping.h */
#define MTDEV_POSITION_X	5
#define MTDEV_POSITION_Y	6
#define MTDEV_ORIENTATION	4
#define MTDEV_PRESSURE		10

void touch_caps_init(struct touch_dev *dev)
{
	const struct mtdev_caps *mt = &dev->mtdev.caps;
	struct touch_caps *caps = &dev->caps;
	caps->min_x = mt->abs[MTDEV_POSITION_X].minimum;
	caps->max_x = mt->abs[MTDEV_POSITION_X].maximum;
	caps->min_y = mt->abs[MTDEV_POSITION_Y].minimum;
	caps->max_y = mt->abs[MTDEV_POSITION_Y].maximum;
	caps->min_orient = mt->abs[MTDEV_ORIENTATION].minimum;
	caps->max_orient = mt->abs[MTDEV_ORIENTATION].maximum;
	caps->min_press = mt->abs[MTDEV_PRESSURE].minimum;
	caps->max_press = mt->abs[MTDEV_PRESSURE].maximum;
	if (caps->min_x == caps->max_x) {
		caps->min_x = 0;
		caps->max_x = 1024;
	}
	if (caps->min_y == caps->max_y) {
		caps->min_y = 0;
		caps->max_y = 768;
	}
	if (caps->min_orient == caps->max_orient) {
		caps->min_orient = 0;
		caps->max_orient = 1;
	}
	if (caps->min_press == caps->max_press) {
		caps->min_press = 0;
		caps->max_press = 256;
	}
}

float touch_angle(const struct touch_dev *dev, int orient)
{
	const struct touch_caps *caps = &dev->caps;
	double div = caps->max_orient - caps->min_orient;
	return ((orient - caps->min_orient) / div - 0.5) * M_PI;
}

float touch_pressure(const struct touch_dev *dev, int press)
{
	const struct touch_caps *caps = &dev->caps;
	return (press - caps->min_press) / (caps->max_press - caps->min_press);
}