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xserver/dix/ptrveloc.c

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/*
*
* 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.
*/
#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif
#include <math.h>
#include <ptrveloc.h>
#include <exevents.h>
#include <X11/Xatom.h>
#include <os.h>
#include <xserver-properties.h>
/*****************************************************************************
* Predictable pointer acceleration
*
* 2006-2009 by Simon Thum (simon [dot] thum [at] gmx de)
*
* Serves 3 complementary functions:
* 1) provide a sophisticated ballistic velocity estimate to improve
* the relation between velocity (of the device) and acceleration
* 2) make arbitrary acceleration profiles possible
* 3) decelerate by two means (constant and adaptive) if enabled
*
* Important concepts are the
*
* - Scheme
* which selects the basic algorithm
* (see devices.c/InitPointerAccelerationScheme)
* - Profile
* which returns an acceleration
* for a given velocity
*
* The profile can be selected by the user at runtime.
* The classic profile is intended to cleanly perform old-style
* function selection (threshold =/!= 0)
*
****************************************************************************/
/* fwds */
static double
SimpleSmoothProfile(DeviceIntPtr dev, DeviceVelocityPtr vel, double velocity,
double threshold, double acc);
static PointerAccelerationProfileFunc
GetAccelerationProfile(DeviceVelocityPtr vel, int profile_num);
static BOOL
InitializePredictableAccelerationProperties(DeviceIntPtr,
DeviceVelocityPtr,
PredictableAccelSchemePtr);
static BOOL
DeletePredictableAccelerationProperties(DeviceIntPtr,
PredictableAccelSchemePtr);
/*#define PTRACCEL_DEBUGGING*/
#ifdef PTRACCEL_DEBUGGING
#define DebugAccelF ErrorF
#else
#define DebugAccelF(...) /* */
#endif
/********************************
* Init/Uninit
*******************************/
/* some int which is not a profile number */
#define PROFILE_UNINITIALIZE (-100)
/**
* Init DeviceVelocity struct so it should match the average case
*/
void
InitVelocityData(DeviceVelocityPtr vel)
{
memset(vel, 0, sizeof(DeviceVelocityRec));
vel->corr_mul = 10.0; /* dots per 10 milisecond should be usable */
vel->const_acceleration = 1.0; /* no acceleration/deceleration */
vel->reset_time = 300;
vel->use_softening = 1;
vel->min_acceleration = 1.0; /* don't decelerate */
vel->max_rel_diff = 0.2;
vel->max_diff = 1.0;
vel->initial_range = 2;
vel->average_accel = TRUE;
SetAccelerationProfile(vel, AccelProfileClassic);
InitTrackers(vel, 16);
}
/**
* Clean up DeviceVelocityRec
*/
void
FreeVelocityData(DeviceVelocityPtr vel)
{
free(vel->tracker);
SetAccelerationProfile(vel, PROFILE_UNINITIALIZE);
}
/**
* Init predictable scheme
*/
Bool
InitPredictableAccelerationScheme(DeviceIntPtr dev,
ValuatorAccelerationPtr protoScheme)
{
DeviceVelocityPtr vel;
ValuatorAccelerationRec scheme;
PredictableAccelSchemePtr schemeData;
scheme = *protoScheme;
vel = calloc(1, sizeof(DeviceVelocityRec));
schemeData = calloc(1, sizeof(PredictableAccelSchemeRec));
if (!vel || !schemeData)
return FALSE;
InitVelocityData(vel);
schemeData->vel = vel;
scheme.accelData = schemeData;
if (!InitializePredictableAccelerationProperties(dev, vel, schemeData))
return FALSE;
/* all fine, assign scheme to device */
dev->valuator->accelScheme = scheme;
return TRUE;
}
/**
* Uninit scheme
*/
void
AccelerationDefaultCleanup(DeviceIntPtr dev)
{
DeviceVelocityPtr vel = GetDevicePredictableAccelData(dev);
if (vel) {
/* the proper guarantee would be that we're not inside of
* AccelSchemeProc(), but that seems impossible. Schemes don't get
* switched often anyway.
*/
OsBlockSignals();
dev->valuator->accelScheme.AccelSchemeProc = NULL;
FreeVelocityData(vel);
free(vel);
DeletePredictableAccelerationProperties(dev,
(PredictableAccelSchemePtr)
dev->valuator->accelScheme.
accelData);
free(dev->valuator->accelScheme.accelData);
dev->valuator->accelScheme.accelData = NULL;
OsReleaseSignals();
}
}
/*************************
* Input property support
************************/
/**
* choose profile
*/
static int
AccelSetProfileProperty(DeviceIntPtr dev, Atom atom,
XIPropertyValuePtr val, BOOL checkOnly)
{
DeviceVelocityPtr vel;
int profile, *ptr = &profile;
int rc;
int nelem = 1;
if (atom != XIGetKnownProperty(ACCEL_PROP_PROFILE_NUMBER))
return Success;
vel = GetDevicePredictableAccelData(dev);
if (!vel)
return BadValue;
rc = XIPropToInt(val, &nelem, &ptr);
if (checkOnly) {
if (rc)
return rc;
if (GetAccelerationProfile(vel, profile) == NULL)
return BadValue;
}
else
SetAccelerationProfile(vel, profile);
return Success;
}
static long
AccelInitProfileProperty(DeviceIntPtr dev, DeviceVelocityPtr vel)
{
int profile = vel->statistics.profile_number;
Atom prop_profile_number = XIGetKnownProperty(ACCEL_PROP_PROFILE_NUMBER);
XIChangeDeviceProperty(dev, prop_profile_number, XA_INTEGER, 32,
PropModeReplace, 1, &profile, FALSE);
XISetDevicePropertyDeletable(dev, prop_profile_number, FALSE);
return XIRegisterPropertyHandler(dev, AccelSetProfileProperty, NULL, NULL);
}
/**
* constant deceleration
*/
static int
AccelSetDecelProperty(DeviceIntPtr dev, Atom atom,
XIPropertyValuePtr val, BOOL checkOnly)
{
DeviceVelocityPtr vel;
float v, *ptr = &v;
int rc;
int nelem = 1;
if (atom != XIGetKnownProperty(ACCEL_PROP_CONSTANT_DECELERATION))
return Success;
vel = GetDevicePredictableAccelData(dev);
if (!vel)
return BadValue;
rc = XIPropToFloat(val, &nelem, &ptr);
if (checkOnly) {
if (rc)
return rc;
return (v >= 1.0f) ? Success : BadValue;
}
if (v >= 1.0f)
vel->const_acceleration = 1 / v;
return Success;
}
static long
AccelInitDecelProperty(DeviceIntPtr dev, DeviceVelocityPtr vel)
{
float fval = 1.0 / vel->const_acceleration;
Atom prop_const_decel =
XIGetKnownProperty(ACCEL_PROP_CONSTANT_DECELERATION);
XIChangeDeviceProperty(dev, prop_const_decel,
XIGetKnownProperty(XATOM_FLOAT), 32, PropModeReplace,
1, &fval, FALSE);
XISetDevicePropertyDeletable(dev, prop_const_decel, FALSE);
return XIRegisterPropertyHandler(dev, AccelSetDecelProperty, NULL, NULL);
}
/**
* adaptive deceleration
*/
static int
AccelSetAdaptDecelProperty(DeviceIntPtr dev, Atom atom,
XIPropertyValuePtr val, BOOL checkOnly)
{
DeviceVelocityPtr veloc;
float v, *ptr = &v;
int rc;
int nelem = 1;
if (atom != XIGetKnownProperty(ACCEL_PROP_ADAPTIVE_DECELERATION))
return Success;
veloc = GetDevicePredictableAccelData(dev);
if (!veloc)
return BadValue;
rc = XIPropToFloat(val, &nelem, &ptr);
if (checkOnly) {
if (rc)
return rc;
return (v >= 1.0f) ? Success : BadValue;
}
if (v >= 1.0f)
veloc->min_acceleration = 1 / v;
return Success;
}
static long
AccelInitAdaptDecelProperty(DeviceIntPtr dev, DeviceVelocityPtr vel)
{
float fval = 1.0 / vel->min_acceleration;
Atom prop_adapt_decel =
XIGetKnownProperty(ACCEL_PROP_ADAPTIVE_DECELERATION);
XIChangeDeviceProperty(dev, prop_adapt_decel,
XIGetKnownProperty(XATOM_FLOAT), 32, PropModeReplace,
1, &fval, FALSE);
XISetDevicePropertyDeletable(dev, prop_adapt_decel, FALSE);
return XIRegisterPropertyHandler(dev, AccelSetAdaptDecelProperty, NULL,
NULL);
}
/**
* velocity scaling
*/
static int
AccelSetScaleProperty(DeviceIntPtr dev, Atom atom,
XIPropertyValuePtr val, BOOL checkOnly)
{
DeviceVelocityPtr vel;
float v, *ptr = &v;
int rc;
int nelem = 1;
if (atom != XIGetKnownProperty(ACCEL_PROP_VELOCITY_SCALING))
return Success;
vel = GetDevicePredictableAccelData(dev);
if (!vel)
return BadValue;
rc = XIPropToFloat(val, &nelem, &ptr);
if (checkOnly) {
if (rc)
return rc;
return (v > 0) ? Success : BadValue;
}
if (v > 0)
vel->corr_mul = v;
return Success;
}
static long
AccelInitScaleProperty(DeviceIntPtr dev, DeviceVelocityPtr vel)
{
float fval = vel->corr_mul;
Atom prop_velo_scale = XIGetKnownProperty(ACCEL_PROP_VELOCITY_SCALING);
XIChangeDeviceProperty(dev, prop_velo_scale,
XIGetKnownProperty(XATOM_FLOAT), 32, PropModeReplace,
1, &fval, FALSE);
XISetDevicePropertyDeletable(dev, prop_velo_scale, FALSE);
return XIRegisterPropertyHandler(dev, AccelSetScaleProperty, NULL, NULL);
}
static BOOL
InitializePredictableAccelerationProperties(DeviceIntPtr dev,
DeviceVelocityPtr vel,
PredictableAccelSchemePtr
schemeData)
{
int num_handlers = 4;
if (!vel)
return FALSE;
schemeData->prop_handlers = calloc(num_handlers, sizeof(long));
if (!schemeData->prop_handlers)
return FALSE;
schemeData->num_prop_handlers = num_handlers;
schemeData->prop_handlers[0] = AccelInitProfileProperty(dev, vel);
schemeData->prop_handlers[1] = AccelInitDecelProperty(dev, vel);
schemeData->prop_handlers[2] = AccelInitAdaptDecelProperty(dev, vel);
schemeData->prop_handlers[3] = AccelInitScaleProperty(dev, vel);
return TRUE;
}
BOOL
DeletePredictableAccelerationProperties(DeviceIntPtr dev,
PredictableAccelSchemePtr scheme)
{
DeviceVelocityPtr vel;
Atom prop;
int i;
prop = XIGetKnownProperty(ACCEL_PROP_VELOCITY_SCALING);
XIDeleteDeviceProperty(dev, prop, FALSE);
prop = XIGetKnownProperty(ACCEL_PROP_ADAPTIVE_DECELERATION);
XIDeleteDeviceProperty(dev, prop, FALSE);
prop = XIGetKnownProperty(ACCEL_PROP_CONSTANT_DECELERATION);
XIDeleteDeviceProperty(dev, prop, FALSE);
prop = XIGetKnownProperty(ACCEL_PROP_PROFILE_NUMBER);
XIDeleteDeviceProperty(dev, prop, FALSE);
vel = GetDevicePredictableAccelData(dev);
if (vel) {
for (i = 0; i < scheme->num_prop_handlers; i++)
if (scheme->prop_handlers[i])
XIUnregisterPropertyHandler(dev, scheme->prop_handlers[i]);
}
free(scheme->prop_handlers);
scheme->prop_handlers = NULL;
scheme->num_prop_handlers = 0;
return TRUE;
}
/*********************
* Tracking logic
********************/
void
InitTrackers(DeviceVelocityPtr vel, int ntracker)
{
if (ntracker < 1) {
ErrorF("(dix ptracc) invalid number of trackers\n");
return;
}
free(vel->tracker);
vel->tracker = (MotionTrackerPtr) calloc(ntracker, sizeof(MotionTracker));
vel->num_tracker = ntracker;
}
enum directions {
N = (1 << 0),
NE = (1 << 1),
E = (1 << 2),
SE = (1 << 3),
S = (1 << 4),
SW = (1 << 5),
W = (1 << 6),
NW = (1 << 7),
UNDEFINED = 0xFF
};
/**
* return a bit field of possible directions.
* There's no reason against widening to more precise directions (<45 degrees),
* should it not perform well. All this is needed for is sort out non-linear
* motion, so precision isn't paramount. However, one should not flag direction
* too narrow, since it would then cut the linear segment to zero size way too
* often.
*
* @return A bitmask for N, NE, S, SE, etc. indicating the directions for
* this movement.
*/
static int
DoGetDirection(int dx, int dy)
{
int dir = 0;
/* on insignificant mickeys, flag 135 degrees */
if (abs(dx) < 2 && abs(dy) < 2) {
/* first check diagonal cases */
if (dx > 0 && dy > 0)
dir = E | SE | S;
else if (dx > 0 && dy < 0)
dir = N | NE | E;
else if (dx < 0 && dy < 0)
dir = W | NW | N;
else if (dx < 0 && dy > 0)
dir = W | SW | S;
/* check axis-aligned directions */
else if (dx > 0)
dir = NE | E | SE;
else if (dx < 0)
dir = NW | W | SW;
else if (dy > 0)
dir = SE | S | SW;
else if (dy < 0)
dir = NE | N | NW;
else
dir = UNDEFINED; /* shouldn't happen */
}
else { /* compute angle and set appropriate flags */
double r;
int i1, i2;
r = atan2(dy, dx);
/* find direction.
*
* Add 360° to avoid r become negative since C has no well-defined
* modulo for such cases. Then divide by 45° to get the octant
* number, e.g.
* 0 <= r <= 1 is [0-45]°
* 1 <= r <= 2 is [45-90]°
* etc.
* But we add extra 90° to match up with our N, S, etc. defines up
* there, rest stays the same.
*/
r = (r + (M_PI * 2.5)) / (M_PI / 4);
/* this intends to flag 2 directions (45 degrees),
* except on very well-aligned mickeys. */
i1 = (int) (r + 0.1) % 8;
i2 = (int) (r + 0.9) % 8;
if (i1 < 0 || i1 > 7 || i2 < 0 || i2 > 7)
dir = UNDEFINED; /* shouldn't happen */
else
dir = (1 << i1 | 1 << i2);
}
return dir;
}
#define DIRECTION_CACHE_RANGE 5
#define DIRECTION_CACHE_SIZE (DIRECTION_CACHE_RANGE*2+1)
/* cache DoGetDirection().
* To avoid excessive use of direction calculation, cache the values for
* [-5..5] for both x/y. Anything outside of that is calcualted on the fly.
*
* @return A bitmask for N, NE, S, SE, etc. indicating the directions for
* this movement.
*/
static int
GetDirection(int dx, int dy)
{
static int cache[DIRECTION_CACHE_SIZE][DIRECTION_CACHE_SIZE];
int dir;
if (abs(dx) <= DIRECTION_CACHE_RANGE && abs(dy) <= DIRECTION_CACHE_RANGE) {
/* cacheable */
dir = cache[DIRECTION_CACHE_RANGE + dx][DIRECTION_CACHE_RANGE + dy];
if (dir == 0) {
dir = DoGetDirection(dx, dy);
cache[DIRECTION_CACHE_RANGE + dx][DIRECTION_CACHE_RANGE + dy] = dir;
}
}
else {
/* non-cacheable */
dir = DoGetDirection(dx, dy);
}
return dir;
}
#undef DIRECTION_CACHE_RANGE
#undef DIRECTION_CACHE_SIZE
/* convert offset (age) to array index */
#define TRACKER_INDEX(s, d) (((s)->num_tracker + (s)->cur_tracker - (d)) % (s)->num_tracker)
#define TRACKER(s, d) &(s)->tracker[TRACKER_INDEX(s,d)]
/**
* Add the delta motion to each tracker, then reset the latest tracker to
* 0/0 and set it as the current one.
*/
static inline void
FeedTrackers(DeviceVelocityPtr vel, double dx, double dy, int cur_t)
{
int n;
for (n = 0; n < vel->num_tracker; n++) {
vel->tracker[n].dx += dx;
vel->tracker[n].dy += dy;
}
n = (vel->cur_tracker + 1) % vel->num_tracker;
vel->tracker[n].dx = 0.0;
vel->tracker[n].dy = 0.0;
vel->tracker[n].time = cur_t;
vel->tracker[n].dir = GetDirection(dx, dy);
DebugAccelF("(dix prtacc) motion [dx: %i dy: %i dir:%i diff: %i]\n",
dx, dy, vel->tracker[n].dir,
cur_t - vel->tracker[vel->cur_tracker].time);
vel->cur_tracker = n;
}
/**
* calc velocity for given tracker, with
* velocity scaling.
* This assumes linear motion.
*/
static double
CalcTracker(const MotionTracker * tracker, int cur_t)
{
double dist = sqrt(tracker->dx * tracker->dx + tracker->dy * tracker->dy);
int dtime = cur_t - tracker->time;
if (dtime > 0)
return dist / dtime;
else
return 0; /* synonymous for NaN, since we're not C99 */
}
/* find the most plausible velocity. That is, the most distant
* (in time) tracker which isn't too old, the movement vector was
* in the same octant, and where the velocity is within an
* acceptable range to the inital velocity.
*
* @return The tracker's velocity or 0 if the above conditions are unmet
*/
static double
QueryTrackers(DeviceVelocityPtr vel, int cur_t)
{
int offset, dir = UNDEFINED, used_offset = -1, age_ms;
/* initial velocity: a low-offset, valid velocity */
double initial_velocity = 0, result = 0, velocity_diff;
double velocity_factor = vel->corr_mul * vel->const_acceleration; /* premultiply */
/* loop from current to older data */
for (offset = 1; offset < vel->num_tracker; offset++) {
MotionTracker *tracker = TRACKER(vel, offset);
double tracker_velocity;
age_ms = cur_t - tracker->time;
/* bail out if data is too old and protect from overrun */
if (age_ms >= vel->reset_time || age_ms < 0) {
DebugAccelF("(dix prtacc) query: tracker too old\n");
break;
}
/*
* this heuristic avoids using the linear-motion velocity formula
* in CalcTracker() on motion that isn't exactly linear. So to get
* even more precision we could subdivide as a final step, so possible
* non-linearities are accounted for.
*/
dir &= tracker->dir;
if (dir == 0) { /* we've changed octant of movement (e.g. NE → NW) */
DebugAccelF("(dix prtacc) query: no longer linear\n");
/* instead of breaking it we might also inspect the partition after,
* but actual improvement with this is probably rare. */
break;
}
tracker_velocity = CalcTracker(tracker, cur_t) * velocity_factor;
if ((initial_velocity == 0 || offset <= vel->initial_range) &&
tracker_velocity != 0) {
/* set initial velocity and result */
result = initial_velocity = tracker_velocity;
used_offset = offset;
}
else if (initial_velocity != 0 && tracker_velocity != 0) {
velocity_diff = fabs(initial_velocity - tracker_velocity);
if (velocity_diff > vel->max_diff &&
velocity_diff / (initial_velocity + tracker_velocity) >=
vel->max_rel_diff) {
/* we're not in range, quit - it won't get better. */
DebugAccelF("(dix prtacc) query: tracker too different:"
" old %2.2f initial %2.2f diff: %2.2f\n",
tracker_velocity, initial_velocity, velocity_diff);
break;
}
/* we're in range with the initial velocity,
* so this result is likely better
* (it contains more information). */
result = tracker_velocity;
used_offset = offset;
}
}
if (offset == vel->num_tracker) {
DebugAccelF("(dix prtacc) query: last tracker in effect\n");
used_offset = vel->num_tracker - 1;
}
if (used_offset >= 0) {
#ifdef PTRACCEL_DEBUGGING
MotionTracker *tracker = TRACKER(vel, used_offset);
DebugAccelF("(dix prtacc) result: offset %i [dx: %i dy: %i diff: %i]\n",
used_offset, tracker->dx, tracker->dy,
cur_t - tracker->time);
#endif
}
return result;
}
#undef TRACKER_INDEX
#undef TRACKER
/**
* Perform velocity approximation based on 2D 'mickeys' (mouse motion delta).
* return true if non-visible state reset is suggested
*/
BOOL
ProcessVelocityData2D(DeviceVelocityPtr vel, double dx, double dy, int time)
{
double velocity;
vel->last_velocity = vel->velocity;
FeedTrackers(vel, dx, dy, time);
velocity = QueryTrackers(vel, time);
vel->velocity = velocity;
return velocity == 0;
}
/**
* this flattens significant ( > 1) mickeys a little bit for more steady
* constant-velocity response
*/
static inline double
ApplySimpleSoftening(double prev_delta, double delta)
{
double result = delta;
if (delta < -1.0 || delta > 1.0) {
if (delta > prev_delta)
result -= 0.5;
else if (delta < prev_delta)
result += 0.5;
}
return result;
}
/**
* Soften the delta based on previous deltas stored in vel.
*
* @param[in,out] fdx Delta X, modified in-place.
* @param[in,out] fdx Delta Y, modified in-place.
*/
static void
ApplySoftening(DeviceVelocityPtr vel, double *fdx, double *fdy)
{
if (vel->use_softening) {
*fdx = ApplySimpleSoftening(vel->last_dx, *fdx);
*fdy = ApplySimpleSoftening(vel->last_dy, *fdy);
}
}
static void
ApplyConstantDeceleration(DeviceVelocityPtr vel, double *fdx, double *fdy)
{
*fdx *= vel->const_acceleration;
*fdy *= vel->const_acceleration;
}
/*
* compute the acceleration for given velocity and enforce min_acceleration
*/
double
BasicComputeAcceleration(DeviceIntPtr dev,
DeviceVelocityPtr vel,
double velocity, double threshold, double acc)
{
double result;
result = vel->Profile(dev, vel, velocity, threshold, acc);
/* enforce min_acceleration */
if (result < vel->min_acceleration)
result = vel->min_acceleration;
return result;
}
/**
* Compute acceleration. Takes into account averaging, nv-reset, etc.
* If the velocity has changed, an average is taken of 6 velocity factors:
* current velocity, last velocity and 4 times the average between the two.
*/
static double
ComputeAcceleration(DeviceIntPtr dev,
DeviceVelocityPtr vel, double threshold, double acc)
{
double result;
if (vel->velocity <= 0) {
DebugAccelF("(dix ptracc) profile skipped\n");
/*
* If we have no idea about device velocity, don't pretend it.
*/
return 1;
}
if (vel->average_accel && vel->velocity != vel->last_velocity) {
/* use simpson's rule to average acceleration between
* current and previous velocity.
* Though being the more natural choice, it causes a minor delay
* in comparison, so it can be disabled. */
result =
BasicComputeAcceleration(dev, vel, vel->velocity, threshold, acc);
result +=
BasicComputeAcceleration(dev, vel, vel->last_velocity, threshold,
acc);
result +=
4.0f * BasicComputeAcceleration(dev, vel,
(vel->last_velocity +
vel->velocity) / 2,
threshold,
acc);
result /= 6.0f;
DebugAccelF("(dix ptracc) profile average [%.2f ... %.2f] is %.3f\n",
vel->velocity, vel->last_velocity, result);
}
else {
result = BasicComputeAcceleration(dev, vel,
vel->velocity, threshold, acc);
DebugAccelF("(dix ptracc) profile sample [%.2f] is %.3f\n",
vel->velocity, res);
}
return result;
}
/*****************************************
* Acceleration functions and profiles
****************************************/
/**
* Polynomial function similar previous one, but with f(1) = 1
*/
static double
PolynomialAccelerationProfile(DeviceIntPtr dev,
DeviceVelocityPtr vel,
double velocity, double ignored, double acc)
{
return pow(velocity, (acc - 1.0) * 0.5);
}
/**
* returns acceleration for velocity.
* This profile selects the two functions like the old scheme did
*/
static double
ClassicProfile(DeviceIntPtr dev,
DeviceVelocityPtr vel,
double velocity, double threshold, double acc)
{
if (threshold > 0) {
return SimpleSmoothProfile(dev, vel, velocity, threshold, acc);
}
else {
return PolynomialAccelerationProfile(dev, vel, velocity, 0, acc);
}
}
/**
* Power profile
* This has a completely smooth transition curve, i.e. no jumps in the
* derivatives.
*
* This has the expense of overall response dependency on min-acceleration.
* In effect, min_acceleration mimics const_acceleration in this profile.
*/
static double
PowerProfile(DeviceIntPtr dev,
DeviceVelocityPtr vel,
double velocity, double threshold, double acc)
{
double vel_dist;
acc = (acc - 1.0) * 0.1f + 1.0; /* without this, acc of 2 is unuseable */
if (velocity <= threshold)
return vel->min_acceleration;
vel_dist = velocity - threshold;
return (pow(acc, vel_dist)) * vel->min_acceleration;
}
/**
* just a smooth function in [0..1] -> [0..1]
* - point symmetry at 0.5
* - f'(0) = f'(1) = 0
* - starts faster than a sinoid
* - smoothness C1 (Cinf if you dare to ignore endpoints)
*/
static inline double
CalcPenumbralGradient(double x)
{
x *= 2.0f;
x -= 1.0f;
return 0.5f + (x * sqrt(1.0 - x * x) + asin(x)) / M_PI;
}
/**
* acceleration function similar to classic accelerated/unaccelerated,
* but with smooth transition in between (and towards zero for adaptive dec.).
*/
static double
SimpleSmoothProfile(DeviceIntPtr dev,
DeviceVelocityPtr vel,
double velocity, double threshold, double acc)
{
if (velocity < 1.0f)
return CalcPenumbralGradient(0.5 + velocity * 0.5) * 2.0f - 1.0f;
if (threshold < 1.0f)
threshold = 1.0f;
if (velocity <= threshold)
return 1;
velocity /= threshold;
if (velocity >= acc)
return acc;
else
return 1.0f + (CalcPenumbralGradient(velocity / acc) * (acc - 1.0f));
}
/**
* This profile uses the first half of the penumbral gradient as a start
* and then scales linearly.
*/
static double
SmoothLinearProfile(DeviceIntPtr dev,
DeviceVelocityPtr vel,
double velocity, double threshold, double acc)
{
double res, nv;
if (acc > 1.0f)
acc -= 1.0f; /*this is so acc = 1 is no acceleration */
else
return 1.0f;
nv = (velocity - threshold) * acc * 0.5f;
if (nv < 0) {
res = 0;
}
else if (nv < 2) {
res = CalcPenumbralGradient(nv * 0.25f) * 2.0f;
}
else {
nv -= 2.0f;
res = nv * 2.0f / M_PI /* steepness of gradient at 0.5 */
+ 1.0f; /* gradient crosses 2|1 */
}
res += vel->min_acceleration;
return res;
}
/**
* From 0 to threshold, the response graduates smoothly from min_accel to
* acceleration. Beyond threshold it is exactly the specified acceleration.
*/
static double
SmoothLimitedProfile(DeviceIntPtr dev,
DeviceVelocityPtr vel,
double velocity, double threshold, double acc)
{
double res;
if (velocity >= threshold || threshold == 0.0f)
return acc;
velocity /= threshold; /* should be [0..1[ now */
res = CalcPenumbralGradient(velocity) * (acc - vel->min_acceleration);
return vel->min_acceleration + res;
}
static double
LinearProfile(DeviceIntPtr dev,
DeviceVelocityPtr vel,
double velocity, double threshold, double acc)
{
return acc * velocity;
}
static double
NoProfile(DeviceIntPtr dev,
DeviceVelocityPtr vel, double velocity, double threshold, double acc)
{
return 1.0f;
}
static PointerAccelerationProfileFunc
GetAccelerationProfile(DeviceVelocityPtr vel, int profile_num)
{
switch (profile_num) {
case AccelProfileClassic:
return ClassicProfile;
case AccelProfileDeviceSpecific:
return vel->deviceSpecificProfile;
case AccelProfilePolynomial:
return PolynomialAccelerationProfile;
case AccelProfileSmoothLinear:
return SmoothLinearProfile;
case AccelProfileSimple:
return SimpleSmoothProfile;
case AccelProfilePower:
return PowerProfile;
case AccelProfileLinear:
return LinearProfile;
case AccelProfileSmoothLimited:
return SmoothLimitedProfile;
case AccelProfileNone:
return NoProfile;
default:
return NULL;
}
}
/**
* Set the profile by number.
* Intended to make profiles exchangeable at runtime.
* If you created a profile, give it a number here and in the header to
* make it selectable. In case some profile-specific init is needed, here
* would be a good place, since FreeVelocityData() also calls this with
* PROFILE_UNINITIALIZE.
*
* returns FALSE if profile number is unavailable, TRUE otherwise.
*/
int
SetAccelerationProfile(DeviceVelocityPtr vel, int profile_num)
{
PointerAccelerationProfileFunc profile;
profile = GetAccelerationProfile(vel, profile_num);
if (profile == NULL && profile_num != PROFILE_UNINITIALIZE)
return FALSE;
/* Here one could free old profile-private data */
free(vel->profile_private);
vel->profile_private = NULL;
/* Here one could init profile-private data */
vel->Profile = profile;
vel->statistics.profile_number = profile_num;
return TRUE;
}
/**********************************************
* driver interaction
**********************************************/
/**
* device-specific profile
*
* The device-specific profile is intended as a hook for a driver
* which may want to provide an own acceleration profile.
* It should not rely on profile-private data, instead
* it should do init/uninit in the driver (ie. with DEVICE_INIT and friends).
* Users may override or choose it.
*/
void
SetDeviceSpecificAccelerationProfile(DeviceVelocityPtr vel,
PointerAccelerationProfileFunc profile)
{
if (vel)
vel->deviceSpecificProfile = profile;
}
/**
* Use this function to obtain a DeviceVelocityPtr for a device. Will return NULL if
* the predictable acceleration scheme is not in effect.
*/
DeviceVelocityPtr
GetDevicePredictableAccelData(DeviceIntPtr dev)
{
/*sanity check */
if (!dev) {
ErrorF("[dix] accel: DeviceIntPtr was NULL");
return NULL;
}
if (dev->valuator &&
dev->valuator->accelScheme.AccelSchemeProc ==
acceleratePointerPredictable &&
dev->valuator->accelScheme.accelData != NULL) {
return ((PredictableAccelSchemePtr)
dev->valuator->accelScheme.accelData)->vel;
}
return NULL;
}
/********************************
* acceleration schemes
*******************************/
/**
* Modifies valuators in-place.
* This version employs a velocity approximation algorithm to
* enable fine-grained predictable acceleration profiles.
*/
void
acceleratePointerPredictable(DeviceIntPtr dev, ValuatorMask *val, CARD32 evtime)
{
double dx = 0, dy = 0;
DeviceVelocityPtr velocitydata = GetDevicePredictableAccelData(dev);
Bool soften = TRUE;
if (valuator_mask_num_valuators(val) == 0 || !velocitydata)
return;
if (velocitydata->statistics.profile_number == AccelProfileNone &&
velocitydata->const_acceleration == 1.0f) {
return; /*we're inactive anyway, so skip the whole thing. */
}
if (valuator_mask_isset(val, 0)) {
dx = valuator_mask_get_double(val, 0);
}
if (valuator_mask_isset(val, 1)) {
dy = valuator_mask_get_double(val, 1);
}
if (dx != 0.0 || dy != 0.0) {
/* reset non-visible state? */
if (ProcessVelocityData2D(velocitydata, dx, dy, evtime)) {
soften = FALSE;
}
if (dev->ptrfeed && dev->ptrfeed->ctrl.num) {
double mult;
/* invoke acceleration profile to determine acceleration */
mult = ComputeAcceleration(dev, velocitydata,
dev->ptrfeed->ctrl.threshold,
(double) dev->ptrfeed->ctrl.num /
(double) dev->ptrfeed->ctrl.den);
if (mult != 1.0f || velocitydata->const_acceleration != 1.0f) {
if (mult > 1.0f && soften)
ApplySoftening(velocitydata, &dx, &dy);
ApplyConstantDeceleration(velocitydata, &dx, &dy);
if (dx != 0.0)
valuator_mask_set_double(val, 0, mult * dx);
if (dy != 0.0)
valuator_mask_set_double(val, 1, mult * dy);
DebugAccelF("pos (%i | %i) delta x:%.3f y:%.3f\n", mult * dx,
mult * dy);
}
}
}
/* remember last motion delta (for softening/slow movement treatment) */
velocitydata->last_dx = dx;
velocitydata->last_dy = dy;
}
/**
* Originally a part of xf86PostMotionEvent; modifies valuators
* in-place. Retained mostly for embedded scenarios.
*/
void
acceleratePointerLightweight(DeviceIntPtr dev,
ValuatorMask *val, CARD32 ignored)
{
double mult = 0.0, tmpf;
double dx = 0.0, dy = 0.0;
if (valuator_mask_isset(val, 0)) {
dx = valuator_mask_get(val, 0);
}
if (valuator_mask_isset(val, 1)) {
dy = valuator_mask_get(val, 1);
}
if (valuator_mask_num_valuators(val) == 0)
return;
if (dev->ptrfeed && dev->ptrfeed->ctrl.num) {
/* modeled from xf86Events.c */
if (dev->ptrfeed->ctrl.threshold) {
if ((fabs(dx) + fabs(dy)) >= dev->ptrfeed->ctrl.threshold) {
if (dx != 0.0) {
tmpf = (dx * (double) (dev->ptrfeed->ctrl.num)) /
(double) (dev->ptrfeed->ctrl.den);
valuator_mask_set_double(val, 0, tmpf);
}
if (dy != 0.0) {
tmpf = (dy * (double) (dev->ptrfeed->ctrl.num)) /
(double) (dev->ptrfeed->ctrl.den);
valuator_mask_set_double(val, 1, tmpf);
}
}
}
else {
mult = pow(dx * dx + dy * dy,
((double) (dev->ptrfeed->ctrl.num) /
(double) (dev->ptrfeed->ctrl.den) - 1.0) / 2.0) / 2.0;
if (dx != 0.0)
valuator_mask_set_double(val, 0, mult * dx);
if (dy != 0.0)
valuator_mask_set_double(val, 1, mult * dy);
}
}
}
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