#ifndef _INPUT_MT_H
#define _INPUT_MT_H

/*
* Input Multitouch Library
*
* Copyright (c) 2010 Henrik Rydberg
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/

#include <linux/input.h>

#define TRKID_MAX 0xffff

#define INPUT_MT_POINTER 0x0001 /* pointer device, e.g. trackpad */
#define INPUT_MT_DIRECT 0x0002 /* direct device, e.g. touchscreen */
#define INPUT_MT_DROP_UNUSED 0x0004 /* drop contacts not seen in frame */
#define INPUT_MT_TRACK 0x0008 /* use in-kernel tracking */
#define INPUT_MT_SEMI_MT 0x0010 /* semi-mt device, finger count handled manually */

/**
* struct input_mt_slot - represents the state of an input MT slot
* @abs: holds current values of ABS_MT axes for this slot
* @frame: last frame at which input_mt_report_slot_state() was called
* @key: optional driver designation of this slot
*/
struct input_mt_slot {
int abs[ABS_MT_LAST - ABS_MT_FIRST + 1];
unsigned int frame;
unsigned int key;
};

/**
* struct input_mt - state of tracked contacts
* @trkid: stores MT tracking ID for the next contact
* @num_slots: number of MT slots the device uses
* @slot: MT slot currently being transmitted
* @flags: input_mt operation flags
* @frame: increases every time input_mt_sync_frame() is called
* @red: reduced cost matrix for in-kernel tracking
* @slots: array of slots holding current values of tracked contacts
*/
struct input_mt {
int trkid;
int num_slots;
int slot;
unsigned int flags;
unsigned int frame;
int *red;
struct input_mt_slot slots[];
};

static inline void input_mt_set_value(struct input_mt_slot *slot,
unsigned code, int value)
{
slot->abs[code - ABS_MT_FIRST] = value;
}

static inline int input_mt_get_value(const struct input_mt_slot *slot,
unsigned code)
{
return slot->abs[code - ABS_MT_FIRST];
}

static inline bool input_mt_is_active(const struct input_mt_slot *slot)
{
return input_mt_get_value(slot, ABS_MT_TRACKING_ID) >= 0;
}

static inline bool input_mt_is_used(const struct input_mt *mt,
const struct input_mt_slot *slot)
{
return slot->frame == mt->frame;
}

int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,
unsigned int flags);
void input_mt_destroy_slots(struct input_dev *dev);

static inline int input_mt_new_trkid(struct input_mt *mt)
{
return mt->trkid++ & TRKID_MAX;
}

static inline void input_mt_slot(struct input_dev *dev, int slot)
{
input_event(dev, EV_ABS, ABS_MT_SLOT, slot);
}

static inline bool input_is_mt_value(int axis)
{
return axis >= ABS_MT_FIRST && axis <= ABS_MT_LAST;
}

static inline bool input_is_mt_axis(int axis)
{
return axis == ABS_MT_SLOT || input_is_mt_value(axis);
}

void input_mt_report_slot_state(struct input_dev *dev,
unsigned int tool_type, bool active);

void input_mt_report_finger_count(struct input_dev *dev, int count);
void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count);

void input_mt_sync_frame(struct input_dev *dev);

/**
* struct input_mt_pos - contact position
* @x: horizontal coordinate
* @y: vertical coordinate
*/
struct input_mt_pos {
s16 x, y;
};

int input_mt_assign_slots(struct input_dev *dev, int *slots,
const struct input_mt_pos *pos, int num_pos);

int input_mt_get_slot_by_key(struct input_dev *dev, int key);

#endif