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19275ea8e9
xserver-multidpi/dix/ptrveloc.c
Simon Thum 19275ea8e9 dix: add property support for pointer acceleration. 
Note: properties don't need to be cleaned up, the DIX does it for us anyway.
Data that is stored in properties is cleaned up by the property system.
Handlers, etc. don't need to be unregistered while cleaning up, as they get
deleted when the device is removed anyway.

Signed-off-by: Peter Hutterer <peter.hutterer@redhat.com>
Signed-off-by: Simon Thum <simon.thum@gmx.de>
2009-01-15 09:28:55 +10:00

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/*
*
* Copyright © 2006-2008 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 <inputstr.h>
#include <exevents.h>
#include <X11/Xatom.h>
#include <assert.h>
#include <os.h>
#include <xserver-properties.h>
/*****************************************************************************
* Predictable pointer acceleration
*
* 2006-2008 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 inline void
FeedFilterStage(FilterStagePtr s, float value, int tdiff);
extern void
InitFilterStage(FilterStagePtr s, float rdecay, int lutsize);
void
CleanupFilterChain(DeviceVelocityPtr s);
int
SetAccelerationProfile(DeviceVelocityPtr s, int profile_num);
void
InitFilterChain(DeviceVelocityPtr s, float rdecay, float degression,
int stages, int lutsize);
void
CleanupFilterChain(DeviceVelocityPtr s);
static float
SimpleSmoothProfile(DeviceVelocityPtr pVel, float velocity,
float threshold, float acc);
static PointerAccelerationProfileFunc
GetAccelerationProfile(DeviceVelocityPtr s, int profile_num);
/*#define PTRACCEL_DEBUGGING*/
#ifdef PTRACCEL_DEBUGGING
#define DebugAccelF ErrorF
#else
#define DebugAccelF(...) /* */
#endif
/********************************
* Init/Uninit etc
*******************************/
/**
* Init struct so it should match the average case
*/
void
InitVelocityData(DeviceVelocityPtr s)
{
memset(s, 0, sizeof(DeviceVelocityRec));
s->corr_mul = 10.0; /* dots per 10 milisecond should be usable */
s->const_acceleration = 1.0; /* no acceleration/deceleration */
s->reset_time = 300;
s->use_softening = 1;
s->min_acceleration = 1.0; /* don't decelerate */
s->coupling = 0.25;
s->average_accel = TRUE;
SetAccelerationProfile(s, AccelProfileClassic);
InitFilterChain(s, (float)1.0/20.0, 1, 1, 40);
}
/**
* Clean up
*/
static void
FreeVelocityData(DeviceVelocityPtr s){
CleanupFilterChain(s);
SetAccelerationProfile(s, -1);
}
/*
* dix uninit helper, called through scheme
*/
void
AccelerationDefaultCleanup(DeviceIntPtr pDev)
{
/*sanity check*/
if( pDev->valuator->accelScheme.AccelSchemeProc == acceleratePointerPredictable
&& pDev->valuator->accelScheme.accelData != NULL){
pDev->valuator->accelScheme.AccelSchemeProc = NULL;
FreeVelocityData(pDev->valuator->accelScheme.accelData);
xfree(pDev->valuator->accelScheme.accelData);
pDev->valuator->accelScheme.accelData = NULL;
}
}
/*************************
* Input property support
************************/
/**
* choose profile
*/
static int
AccelSetProfileProperty(DeviceIntPtr dev, Atom atom,
XIPropertyValuePtr val, BOOL checkOnly)
{
DeviceVelocityPtr pVel;
int profile, *ptr = &profile;
int rc;
int nelem = 1;
if (atom != XIGetKnownProperty(ACCEL_PROP_PROFILE_NUMBER))
return Success;
pVel = GetDevicePredictableAccelData(dev);
if (!pVel)
return BadValue;
rc = XIPropToInt(val, &nelem, &ptr);
if(checkOnly)
{
if (rc)
return rc;
if (GetAccelerationProfile(pVel, profile) == NULL)
return BadValue;
} else
SetAccelerationProfile(pVel, profile);
return Success;
}
static void
AccelInitProfileProperty(DeviceIntPtr dev, DeviceVelocityPtr pVel)
{
int profile = pVel->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);
XIRegisterPropertyHandler(dev, AccelSetProfileProperty, NULL, NULL);
}
/**
* constant deceleration
*/
static int
AccelSetDecelProperty(DeviceIntPtr dev, Atom atom,
XIPropertyValuePtr val, BOOL checkOnly)
{
DeviceVelocityPtr pVel;
float v, *ptr = &v;
int rc;
int nelem = 1;
if (atom != XIGetKnownProperty(ACCEL_PROP_CONSTANT_DECELERATION))
return Success;
pVel = GetDevicePredictableAccelData(dev);
if (!pVel)
return BadValue;
rc = XIPropToFloat(val, &nelem, &ptr);
if(checkOnly)
{
if (rc)
return rc;
return (v >= 1.0f) ? Success : BadValue;
}
if(v >= 1.0f)
pVel->const_acceleration = 1/v;
return Success;
}
static void
AccelInitDecelProperty(DeviceIntPtr dev, DeviceVelocityPtr pVel)
{
float fval = 1.0/pVel->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);
XIRegisterPropertyHandler(dev, AccelSetDecelProperty, NULL, NULL);
}
/**
* adaptive deceleration
*/
static int
AccelSetAdaptDecelProperty(DeviceIntPtr dev, Atom atom,
XIPropertyValuePtr val, BOOL checkOnly)
{
DeviceVelocityPtr pVel;
float v, *ptr = &v;
int rc;
int nelem = 1;
if (atom != XIGetKnownProperty(ACCEL_PROP_ADAPTIVE_DECELERATION))
return Success;
pVel = GetDevicePredictableAccelData(dev);
if (!pVel)
return BadValue;
rc = XIPropToFloat(val, &nelem, &ptr);
if(checkOnly)
{
if (rc)
return rc;
return (v >= 1.0f) ? Success : BadValue;
}
if(v >= 1.0f)
pVel->min_acceleration = 1/v;
return Success;
}
static void
AccelInitAdaptDecelProperty(DeviceIntPtr dev, DeviceVelocityPtr pVel)
{
float fval = 1.0/pVel->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);
XIRegisterPropertyHandler(dev, AccelSetAdaptDecelProperty, NULL, NULL);
}
/**
* velocity scaling
*/
static int
AccelSetScaleProperty(DeviceIntPtr dev, Atom atom,
XIPropertyValuePtr val, BOOL checkOnly)
{
DeviceVelocityPtr pVel;
float v, *ptr = &v;
int rc;
int nelem = 1;
if (atom != XIGetKnownProperty(ACCEL_PROP_VELOCITY_SCALING))
return Success;
pVel = GetDevicePredictableAccelData(dev);
if (!pVel)
return BadValue;
rc = XIPropToFloat(val, &nelem, &ptr);
if (checkOnly)
{
if (rc)
return rc;
return (v > 0) ? Success : BadValue;
}
if(v > 0)
pVel->corr_mul = v;
return Success;
}
static void
AccelInitScaleProperty(DeviceIntPtr dev, DeviceVelocityPtr pVel)
{
float fval = pVel->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);
XIRegisterPropertyHandler(dev, AccelSetScaleProperty, NULL, NULL);
}
BOOL
InitializePredictableAccelerationProperties(DeviceIntPtr device)
{
DeviceVelocityPtr pVel = GetDevicePredictableAccelData(device);
if(!pVel)
return FALSE;
AccelInitProfileProperty(device, pVel);
AccelInitDecelProperty(device, pVel);
AccelInitAdaptDecelProperty(device, pVel);
AccelInitScaleProperty(device, pVel);
return TRUE;
}
/*********************
* Filtering logic
********************/
/**
Initialize a filter chain.
Expected result is a series of filters, each progressively more integrating.
This allows for two strategies: Either you have one filter which is reasonable
and is being coupled to account for fast-changing input, or you have 'one for
every situation'. You might want to have tighter coupling then, e.g. 0.1.
In the filter stats, you can see if a reasonable filter useage emerges.
*/
void
InitFilterChain(DeviceVelocityPtr s, float rdecay, float progression, int stages, int lutsize)
{
int fn;
if((stages > 1 && progression < 1.0f) || 0 == progression){
ErrorF("(dix ptracc) invalid filter chain progression specified\n");
return;
}
/* Block here to support runtime filter adjustment */
OsBlockSignals();
for(fn = 0; fn < MAX_VELOCITY_FILTERS; fn++){
if(fn < stages){
InitFilterStage(&s->filters[fn], rdecay, lutsize);
}else{
InitFilterStage(&s->filters[fn], 0, 0);
}
rdecay /= progression;
}
/* release again. Should the input loop be threaded, we also need
* memory release here (in principle).
*/
OsReleaseSignals();
}
void
CleanupFilterChain(DeviceVelocityPtr s)
{
int fn;
for(fn = 0; fn < MAX_VELOCITY_FILTERS; fn++)
InitFilterStage(&s->filters[fn], 0, 0);
}
static inline void
StuffFilterChain(DeviceVelocityPtr s, float value)
{
int fn;
for(fn = 0; fn < MAX_VELOCITY_FILTERS; fn++){
if(s->filters[fn].rdecay != 0)
s->filters[fn].current = value;
else break;
}
}
/**
* Adjust weighting decay and lut for a stage
* The weight fn is designed so its integral 0->inf is unity, so we end
* up with a stable (basically IIR) filter. It always draws
* towards its more current input values, which have more weight the older
* the last input value is.
*/
void
InitFilterStage(FilterStagePtr s, float rdecay, int lutsize)
{
int x;
float *newlut;
float *oldlut;
s->fading_lut_size = 0; /* prevent access */
if(lutsize > 0){
newlut = xalloc (sizeof(float)* lutsize);
if(!newlut)
return;
for(x = 0; x < lutsize; x++)
newlut[x] = pow(0.5, ((float)x) * rdecay);
}else{
newlut = NULL;
}
oldlut = s->fading_lut;
s->fading_lut = newlut;
s->rdecay = rdecay;
s->fading_lut_size = lutsize;
s->current = 0;
if(oldlut != NULL)
xfree(oldlut);
}
static inline void
FeedFilterChain(DeviceVelocityPtr s, float value, int tdiff)
{
int fn;
for(fn = 0; fn < MAX_VELOCITY_FILTERS; fn++){
if(s->filters[fn].rdecay != 0)
FeedFilterStage(&s->filters[fn], value, tdiff);
else break;
}
}
static inline void
FeedFilterStage(FilterStagePtr s, float value, int tdiff){
float fade;
if(tdiff < s->fading_lut_size)
fade = s->fading_lut[tdiff];
else
fade = pow(0.5, ((float)tdiff) * s->rdecay);
s->current *= fade; /* fade out old velocity */
s->current += value * (1.0f - fade); /* and add up current */
}
/**
* Select the most filtered matching result. Also, the first
* mismatching filter may be set to value (coupling).
*/
static inline float
QueryFilterChain(
DeviceVelocityPtr s,
float value)
{
int fn, rfn = 0, cfn = -1;
float cur, result = value;
/* try to retrieve most integrated result 'within range'
* Assumption: filter are in order least to most integrating */
for(fn = 0; fn < MAX_VELOCITY_FILTERS; fn++){
if(0.0f == s->filters[fn].rdecay)
break;
cur = s->filters[fn].current;
if (fabs(value - cur) <= (s->coupling * (value + cur))){
result = cur;
rfn = fn + 1; /*remember result determining filter */
} else if(cfn == -1){
cfn = fn; /* remember first mismatching filter */
}
}
s->statistics.filter_usecount[rfn]++;
DebugAccelF("(dix ptracc) result from stage %i, input %.2f, output %.2f\n",
rfn, value, result);
/* override first mismatching current (coupling) so the filter
* catches up quickly. */
if(cfn != -1)
s->filters[cfn].current = result;
return result;
}
/********************************
* velocity computation
*******************************/
/**
* return the axis if mickey is insignificant and axis-aligned,
* -1 otherwise
* 1 for x-axis
* 2 for y-axis
*/
static inline short
GetAxis(int dx, int dy){
if(dx == 0 || dy == 0){
if(dx == 1 || dx == -1)
return 1;
if(dy == 1 || dy == -1)
return 2;
return -1;
}else{
return -1;
}
}
/**
* Perform velocity approximation
* return true if non-visible state reset is suggested
*/
static short
ProcessVelocityData(
DeviceVelocityPtr s,
int dx,
int dy,
int time)
{
float cvelocity;
int diff = time - s->lrm_time;
int cur_ax, last_ax;
short reset = (diff >= s->reset_time);
/* remember last round's result */
s->last_velocity = s->velocity;
cur_ax = GetAxis(dx, dy);
last_ax = GetAxis(s->last_dx, s->last_dy);
if(cur_ax != last_ax && cur_ax != -1 && last_ax != -1 && !reset){
/* correct for the error induced when diagonal movements are
reported as alternating axis mickeys */
dx += s->last_dx;
dy += s->last_dy;
diff += s->last_diff;
s->last_diff = time - s->lrm_time; /* prevent repeating add-up */
DebugAccelF("(dix ptracc) axial correction\n");
}else{
s->last_diff = diff;
}
/*
* cvelocity is not a real velocity yet, more a motion delta. constant
* acceleration is multiplied here to make the velocity an on-screen
* velocity (pix/t as opposed to [insert unit]/t). This is intended to
* make multiple devices with widely varying ConstantDecelerations respond
* similar to acceleration controls.
*/
cvelocity = (float)sqrt(dx*dx + dy*dy) * s->const_acceleration;
s->lrm_time = time;
if (s->reset_time < 0 || diff < 0) { /* reset disabled or timer overrun? */
/* simply set velocity from current movement, no reset. */
s->velocity = cvelocity;
return FALSE;
}
if (diff == 0)
diff = 1; /* prevent div-by-zero, though it shouldn't happen anyway*/
/* translate velocity to dots/ms (somewhat intractable in integers,
so we multiply by some per-device adjustable factor) */
cvelocity = cvelocity * s->corr_mul / (float)diff;
/* short-circuit: when nv-reset the rest can be skipped */
if(reset == TRUE){
/*
* we don't really have a velocity here, since diff includes inactive
* time. This is dealt with in ComputeAcceleration.
*/
StuffFilterChain(s, cvelocity);
s->velocity = s->last_velocity = cvelocity;
s->last_reset = TRUE;
DebugAccelF("(dix ptracc) non-visible state reset\n");
return TRUE;
}
if(s->last_reset == TRUE){
/*
* when here, we're probably processing the second mickey of a starting
* stroke. This happens to be the first time we can reasonably pretend
* that cvelocity is an actual velocity. Thus, to opt precision, we
* stuff that into the filter chain.
*/
s->last_reset = FALSE;
DebugAccelF("(dix ptracc) after-reset vel:%.3f\n", cvelocity);
StuffFilterChain(s, cvelocity);
s->velocity = cvelocity;
return FALSE;
}
/* feed into filter chain */
FeedFilterChain(s, cvelocity, diff);
/* perform coupling and decide final value */
s->velocity = QueryFilterChain(s, cvelocity);
DebugAccelF("(dix ptracc) guess: vel=%.3f diff=%d %i|%i|%i|%i|%i|%i|%i|%i|%i\n",
s->velocity, diff,
s->statistics.filter_usecount[0], s->statistics.filter_usecount[1],
s->statistics.filter_usecount[2], s->statistics.filter_usecount[3],
s->statistics.filter_usecount[4], s->statistics.filter_usecount[5],
s->statistics.filter_usecount[6], s->statistics.filter_usecount[7],
s->statistics.filter_usecount[8]);
return FALSE;
}
/**
* this flattens significant ( > 1) mickeys a little bit for more steady
* constant-velocity response
*/
static inline float
ApplySimpleSoftening(int od, int d)
{
float res = d;
if (d <= 1 && d >= -1)
return res;
if (d > od)
res -= 0.5;
else if (d < od)
res += 0.5;
return res;
}
static void
ApplySofteningAndConstantDeceleration(
DeviceVelocityPtr s,
int dx,
int dy,
float* fdx,
float* fdy,
short do_soften)
{
if (do_soften && s->use_softening) {
*fdx = ApplySimpleSoftening(s->last_dx, dx);
*fdy = ApplySimpleSoftening(s->last_dy, dy);
} else {
*fdx = dx;
*fdy = dy;
}
*fdx *= s->const_acceleration;
*fdy *= s->const_acceleration;
}
/*
* compute the acceleration for given velocity and enforce min_acceleartion
*/
static float
BasicComputeAcceleration(
DeviceVelocityPtr pVel,
float velocity,
float threshold,
float acc){
float result;
result = pVel->Profile(pVel, velocity, threshold, acc);
/* enforce min_acceleration */
if (result < pVel->min_acceleration)
result = pVel->min_acceleration;
return result;
}
/**
* Compute acceleration. Takes into account averaging, nv-reset, etc.
*/
static float
ComputeAcceleration(
DeviceVelocityPtr vel,
float threshold,
float acc){
float res;
if(vel->last_reset){
DebugAccelF("(dix ptracc) profile skipped\n");
/*
* This is intended to override the first estimate of a stroke,
* which is too low (see ProcessVelocityData). 1 should make sure
* the mickey is seen on screen.
*/
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. */
res = BasicComputeAcceleration(vel, vel->velocity, threshold, acc);
res += BasicComputeAcceleration(vel, vel->last_velocity, threshold, acc);
res += 4.0f * BasicComputeAcceleration(vel,
(vel->last_velocity + vel->velocity) / 2,
threshold, acc);
res /= 6.0f;
DebugAccelF("(dix ptracc) profile average [%.2f ... %.2f] is %.3f\n",
vel->velocity, vel->last_velocity, res);
return res;
}else{
res = BasicComputeAcceleration(vel, vel->velocity, threshold, acc);
DebugAccelF("(dix ptracc) profile sample [%.2f] is %.3f\n",
vel->velocity, res);
return res;
}
}
/*****************************************
* Acceleration functions and profiles
****************************************/
/**
* Polynomial function similar previous one, but with f(1) = 1
*/
static float
PolynomialAccelerationProfile(
DeviceVelocityPtr pVel,
float velocity,
float ignored,
float 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 float
ClassicProfile(
DeviceVelocityPtr pVel,
float velocity,
float threshold,
float acc)
{
if (threshold) {
return SimpleSmoothProfile (pVel,
velocity,
threshold,
acc);
} else {
return PolynomialAccelerationProfile (pVel,
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 float
PowerProfile(
DeviceVelocityPtr pVel,
float velocity,
float threshold,
float acc)
{
float vel_dist;
acc = (acc-1.0) * 0.1f + 1.0; /* without this, acc of 2 is unuseable */
if (velocity <= threshold)
return pVel->min_acceleration;
vel_dist = velocity - threshold;
return (pow(acc, vel_dist)) * pVel->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 float
CalcPenumbralGradient(float x){
x *= 2.0f;
x -= 1.0f;
return 0.5f + (x * sqrt(1.0f - 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 float
SimpleSmoothProfile(
DeviceVelocityPtr pVel,
float velocity,
float threshold,
float 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 float
SmoothLinearProfile(
DeviceVelocityPtr pVel,
float velocity,
float threshold,
float acc)
{
float 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 += pVel->min_acceleration;
return res;
}
static float
LinearProfile(
DeviceVelocityPtr pVel,
float velocity,
float threshold,
float acc)
{
return acc * velocity;
}
static PointerAccelerationProfileFunc
GetAccelerationProfile(
DeviceVelocityPtr s,
int profile_num)
{
switch(profile_num){
case AccelProfileClassic:
return ClassicProfile;
case AccelProfileDeviceSpecific:
return s->deviceSpecificProfile;
case AccelProfilePolynomial:
return PolynomialAccelerationProfile;
case AccelProfileSmoothLinear:
return SmoothLinearProfile;
case AccelProfileSimple:
return SimpleSmoothProfile;
case AccelProfilePower:
return PowerProfile;
case AccelProfileLinear:
return LinearProfile;
case AccelProfileReserved:
/* reserved for future use, e.g. a user-defined profile */
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 -1.
* returns FALSE (0) if profile number is unavailable.
*/
int
SetAccelerationProfile(
DeviceVelocityPtr s,
int profile_num)
{
PointerAccelerationProfileFunc profile;
profile = GetAccelerationProfile(s, profile_num);
if(profile == NULL && profile_num != -1)
return FALSE;
if(s->profile_private != NULL){
/* Here one could free old profile-private data */
xfree(s->profile_private);
s->profile_private = NULL;
}
/* Here one could init profile-private data */
s->Profile = profile;
s->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 s,
PointerAccelerationProfileFunc profile)
{
if(s)
s->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 pDev)
{
/*sanity check*/
if(!pDev){
ErrorF("[dix] accel: DeviceIntPtr was NULL");
return NULL;
}
if( pDev->valuator &&
pDev->valuator->accelScheme.AccelSchemeProc ==
acceleratePointerPredictable &&
pDev->valuator->accelScheme.accelData != NULL){
return (DeviceVelocityPtr)pDev->valuator->accelScheme.accelData;
}
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 pDev,
int first_valuator,
int num_valuators,
int *valuators,
int evtime)
{
float mult = 0.0;
int dx = 0, dy = 0;
int *px = NULL, *py = NULL;
DeviceVelocityPtr velocitydata =
(DeviceVelocityPtr) pDev->valuator->accelScheme.accelData;
float fdx, fdy; /* no need to init */
if (!num_valuators || !valuators || !velocitydata)
return;
if (first_valuator == 0) {
dx = valuators[0];
px = &valuators[0];
}
if (first_valuator <= 1 && num_valuators >= (2 - first_valuator)) {
dy = valuators[1 - first_valuator];
py = &valuators[1 - first_valuator];
}
if (dx || dy){
/* reset nonvisible state? */
if (ProcessVelocityData(velocitydata, dx , dy, evtime)) {
/* set to center of pixel. makes sense as long as there are no
* means of passing on sub-pixel values.
*/
pDev->last.remainder[0] = pDev->last.remainder[1] = 0.5f;
/* prevent softening (somewhat quirky solution,
as it depends on the algorithm) */
velocitydata->last_dx = dx;
velocitydata->last_dy = dy;
}
if (pDev->ptrfeed && pDev->ptrfeed->ctrl.num) {
/* invoke acceleration profile to determine acceleration */
mult = ComputeAcceleration (velocitydata,
pDev->ptrfeed->ctrl.threshold,
(float)pDev->ptrfeed->ctrl.num /
(float)pDev->ptrfeed->ctrl.den);
if(mult != 1.0 || velocitydata->const_acceleration != 1.0) {
ApplySofteningAndConstantDeceleration( velocitydata,
dx, dy,
&fdx, &fdy,
mult > 1.0);
if (dx) {
pDev->last.remainder[0] = mult * fdx + pDev->last.remainder[0];
*px = (int)pDev->last.remainder[0];
pDev->last.remainder[0] = pDev->last.remainder[0] - (float)*px;
}
if (dy) {
pDev->last.remainder[1] = mult * fdy + pDev->last.remainder[1];
*py = (int)pDev->last.remainder[1];
pDev->last.remainder[1] = pDev->last.remainder[1] - (float)*py;
}
}
}
}
/* 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 pDev,
int first_valuator,
int num_valuators,
int *valuators,
int ignored)
{
float mult = 0.0;
int dx = 0, dy = 0;
int *px = NULL, *py = NULL;
if (!num_valuators || !valuators)
return;
if (first_valuator == 0) {
dx = valuators[0];
px = &valuators[0];
}
if (first_valuator <= 1 && num_valuators >= (2 - first_valuator)) {
dy = valuators[1 - first_valuator];
py = &valuators[1 - first_valuator];
}
if (!dx && !dy)
return;
if (pDev->ptrfeed && pDev->ptrfeed->ctrl.num) {
/* modeled from xf86Events.c */
if (pDev->ptrfeed->ctrl.threshold) {
if ((abs(dx) + abs(dy)) >= pDev->ptrfeed->ctrl.threshold) {
pDev->last.remainder[0] = ((float)dx *
(float)(pDev->ptrfeed->ctrl.num)) /
(float)(pDev->ptrfeed->ctrl.den) +
pDev->last.remainder[0];
if (px) {
*px = (int)pDev->last.remainder[0];
pDev->last.remainder[0] = pDev->last.remainder[0] -
(float)(*px);
}
pDev->last.remainder[1] = ((float)dy *
(float)(pDev->ptrfeed->ctrl.num)) /
(float)(pDev->ptrfeed->ctrl.den) +
pDev->last.remainder[1];
if (py) {
*py = (int)pDev->last.remainder[1];
pDev->last.remainder[1] = pDev->last.remainder[1] -
(float)(*py);
}
}
}
else {
mult = pow((float)dx * (float)dx + (float)dy * (float)dy,
((float)(pDev->ptrfeed->ctrl.num) /
(float)(pDev->ptrfeed->ctrl.den) - 1.0) /
2.0) / 2.0;
if (dx) {
pDev->last.remainder[0] = mult * (float)dx +
pDev->last.remainder[0];
*px = (int)pDev->last.remainder[0];
pDev->last.remainder[0] = pDev->last.remainder[0] -
(float)(*px);
}
if (dy) {
pDev->last.remainder[1] = mult * (float)dy +
pDev->last.remainder[1];
*py = (int)pDev->last.remainder[1];
pDev->last.remainder[1] = pDev->last.remainder[1] -
(float)(*py);
}
}
}
}
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