/*
 *
 * Copyright © 2006-2009 Simon Thum             simon dot thum at gmx dot de
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#ifndef POINTERVELOCITY_H
#define POINTERVELOCITY_H

#include <input.h> /* DeviceIntPtr */

/* constants for acceleration profiles */

#define AccelProfileNone -1
#define AccelProfileClassic  0
#define AccelProfileDeviceSpecific 1
#define AccelProfilePolynomial 2
#define AccelProfileSmoothLinear 3
#define AccelProfileSimple 4
#define AccelProfilePower 5
#define AccelProfileLinear 6
#define AccelProfileSmoothLimited 7
#define AccelProfileLAST AccelProfileSmoothLimited

/* fwd */
struct _DeviceVelocityRec;

/**
 * profile
 * returns actual acceleration depending on velocity, acceleration control,...
 */
typedef float (*PointerAccelerationProfileFunc)
              (DeviceIntPtr dev, struct _DeviceVelocityRec* vel,
               float velocity, float threshold, float accelCoeff);

/**
 * a motion history, with just enough information to
 * calc mean velocity and decide which motion was along
 * a more or less straight line
 */
typedef struct _MotionTracker {
    int dx, dy;     /* accumulated delta for each axis */
    int time;         /* time of creation */
    int dir;        /* initial direction bitfield */
} MotionTracker, *MotionTrackerPtr;

/* number of properties for predictable acceleration */
#define NPROPS_PREDICTABLE_ACCEL 4

/**
 * Contains all data needed to implement mouse ballistics
 */
typedef struct _DeviceVelocityRec {
    MotionTrackerPtr tracker;
    int num_tracker;
    int cur_tracker;        /* current index */
    float   velocity;       /* velocity as guessed by algorithm */
    float   last_velocity;  /* previous velocity estimate */
    int     last_dx;      /* last time-difference */
    int     last_dy ;     /* phase of last/current estimate */
    float   corr_mul;       /* config: multiply this into velocity */
    float   const_acceleration;  /* config: (recipr.) const deceleration */
    float   min_acceleration;    /* config: minimum acceleration */
    short   reset_time;     /* config: reset non-visible state after # ms */
    short   use_softening;  /* config: use softening of mouse values */
    float   max_rel_diff;   /* config: max. relative difference */
    float   max_diff;       /* config: max. difference */
    int     initial_range;  /* config: max. offset used as initial velocity */
    Bool    average_accel;  /* config: average acceleration over velocity */
    PointerAccelerationProfileFunc Profile;
    PointerAccelerationProfileFunc deviceSpecificProfile;
    void*   profile_private;/* extended data, see  SetAccelerationProfile() */
    struct {   /* to be able to query this information */
        int     profile_number;
    } statistics;
    long    prop_handlers[NPROPS_PREDICTABLE_ACCEL];
} DeviceVelocityRec, *DeviceVelocityPtr;

extern _X_EXPORT void
InitVelocityData(DeviceVelocityPtr vel);

extern _X_EXPORT void
InitTrackers(DeviceVelocityPtr vel, int ntracker);

extern _X_EXPORT short
ProcessVelocityData2D(DeviceVelocityPtr vel, int dx, int dy, int time);

extern _X_EXPORT float
BasicComputeAcceleration(DeviceIntPtr dev, DeviceVelocityPtr vel,
    float velocity, float threshold, float acc);

extern _X_EXPORT void
FreeVelocityData(DeviceVelocityPtr vel);

extern _X_INTERNAL BOOL
InitializePredictableAccelerationProperties(DeviceIntPtr dev);

extern _X_INTERNAL BOOL
DeletePredictableAccelerationProperties(DeviceIntPtr dev);

extern _X_EXPORT int
SetAccelerationProfile(DeviceVelocityPtr vel, int profile_num);

extern _X_EXPORT DeviceVelocityPtr
GetDevicePredictableAccelData(DeviceIntPtr dev);

extern _X_EXPORT void
SetDeviceSpecificAccelerationProfile(DeviceVelocityPtr vel,
                                     PointerAccelerationProfileFunc profile);

extern _X_INTERNAL void
AccelerationDefaultCleanup(DeviceIntPtr dev);

extern _X_INTERNAL void
acceleratePointerPredictable(DeviceIntPtr dev, int first_valuator,
                             int num_valuators, int *valuators, int evtime);

extern _X_INTERNAL void
acceleratePointerLightweight(DeviceIntPtr dev, int first_valuator,
                             int num_valuators, int *valuators, int ignored);

#endif  /* POINTERVELOCITY_H */
