initial state (xorg-server 1.10.2)

1 files changed, 1175 insertions, 0 deletions

diff --git a/dix/ptrveloc.c b/dix/ptrveloc.c
new file mode 100644
index 0000000..4d5dad7
--- /dev/null
+++ b/dix/ptrveloc.c
@@ -0,0 +1,1175 @@
+/*
+ *
+ * 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 <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 */
+int
+SetAccelerationProfile(DeviceVelocityPtr vel, int profile_num);
+static float
+SimpleSmoothProfile(DeviceIntPtr dev, DeviceVelocityPtr vel, float velocity,
+                    float threshold, float acc);
+static PointerAccelerationProfileFunc
+GetAccelerationProfile(DeviceVelocityPtr vel, int profile_num);
+
+/*#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 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
+ */
+void
+FreeVelocityData(DeviceVelocityPtr vel){
+    free(vel->tracker);
+    SetAccelerationProfile(vel, PROFILE_UNINITIALIZE);
+}
+
+
+/*
+ *  dix uninit helper, called through scheme
+ */
+void
+AccelerationDefaultCleanup(DeviceIntPtr dev)
+{
+    /*sanity check*/
+    if( dev->valuator->accelScheme.AccelSchemeProc == acceleratePointerPredictable
+            && dev->valuator->accelScheme.accelData != NULL){
+        dev->valuator->accelScheme.AccelSchemeProc = NULL;
+        FreeVelocityData(dev->valuator->accelScheme.accelData);
+        free(dev->valuator->accelScheme.accelData);
+        dev->valuator->accelScheme.accelData = NULL;
+        DeletePredictableAccelerationProperties(dev);
+    }
+}
+
+
+/*************************
+ * 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);
+}
+
+BOOL
+InitializePredictableAccelerationProperties(DeviceIntPtr dev)
+{
+    DeviceVelocityPtr  vel = GetDevicePredictableAccelData(dev);
+
+    if(!vel)
+	return FALSE;
+
+    vel->prop_handlers[0] = AccelInitProfileProperty(dev, vel);
+    vel->prop_handlers[1] = AccelInitDecelProperty(dev, vel);
+    vel->prop_handlers[2] = AccelInitAdaptDecelProperty(dev, vel);
+    vel->prop_handlers[3] = AccelInitScaleProperty(dev, vel);
+
+    return TRUE;
+}
+
+BOOL
+DeletePredictableAccelerationProperties(DeviceIntPtr dev)
+{
+    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);
+    for (i = 0; vel && i < NPROPS_PREDICTABLE_ACCEL; i++)
+	if (vel->prop_handlers[i])
+	    XIUnregisterPropertyHandler(dev, vel->prop_handlers[i]);
+
+    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)malloc(ntracker * sizeof(MotionTracker));
+    memset(vel->tracker, 0, ntracker * sizeof(MotionTracker));
+    vel->num_tracker = ntracker;
+}
+
+/**
+ * return a bit field of possible directions.
+ * 0 = N, 2 = E, 4 = S, 6 = W, in-between is as you guess.
+ * 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.
+ */
+static int
+DoGetDirection(int dx, int dy){
+    float r;
+    int i1, i2;
+    /* on insignificant mickeys, flag 135 degrees */
+    if(abs(dx) < 2 && abs(dy) < 2){
+	/* first check diagonal cases */
+	if(dx > 0 && dy > 0)
+	    return 4+8+16;
+	if(dx > 0 && dy < 0)
+	    return 1+2+4;
+	if(dx < 0 && dy < 0)
+	    return 1+128+64;
+	if(dx < 0 && dy > 0)
+	    return 16+32+64;
+        /* check axis-aligned directions */
+	if(dx > 0)
+            return 2+4+8; /*E*/
+        if(dx < 0)
+            return 128+64+32; /*W*/
+        if(dy > 0)
+            return 32+16+8; /*S*/
+        if(dy < 0)
+            return 128+1+2; /*N*/
+        return 255; /* shouldn't happen */
+    }
+    /* else, compute angle and set appropriate flags */
+#ifdef _ISOC99_SOURCE
+    r = atan2f(dy, dx);
+#else
+    r = atan2(dy, dx);
+#endif
+    /* find direction. We avoid r to become negative,
+     * since C has no well-defined modulo for such cases. */
+    r = (r+(M_PI*2.5))/(M_PI/4);
+    /* this intends to flag 2 directions (90 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)
+	return 255; /* shouldn't happen */
+    return 1 << i1 | 1 << i2;
+}
+
+#define DIRECTION_CACHE_RANGE 5
+#define DIRECTION_CACHE_SIZE (DIRECTION_CACHE_RANGE*2+1)
+
+/* cache DoGetDirection(). */
+static int
+GetDirection(int dx, int dy){
+    static int cache[DIRECTION_CACHE_SIZE][DIRECTION_CACHE_SIZE];
+    int i;
+    if (abs(dx) <= DIRECTION_CACHE_RANGE &&
+	abs(dy) <= DIRECTION_CACHE_RANGE) {
+	/* cacheable */
+	i = cache[DIRECTION_CACHE_RANGE+dx][DIRECTION_CACHE_RANGE+dy];
+	if(i != 0){
+	    return i;
+	}else{
+	    i = DoGetDirection(dx, dy);
+	    cache[DIRECTION_CACHE_RANGE+dx][DIRECTION_CACHE_RANGE+dy] = i;
+	    return i;
+	}
+    }else{
+	/* non-cacheable */
+	return DoGetDirection(dx, dy);
+    }
+}
+
+#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)
+
+static inline void
+FeedTrackers(DeviceVelocityPtr vel, int dx, int 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;
+    vel->tracker[n].dy = 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 float
+CalcTracker(DeviceVelocityPtr vel, int offset, int cur_t){
+    int index = TRACKER_INDEX(vel, offset);
+    float dist = sqrt(  vel->tracker[index].dx * vel->tracker[index].dx
+                      + vel->tracker[index].dy * vel->tracker[index].dy);
+    int dtime = cur_t - vel->tracker[index].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, beyond a linear partition,
+ * or simply too much off initial velocity.
+ *
+ * May return 0.
+ */
+static float
+QueryTrackers(DeviceVelocityPtr vel, int cur_t){
+    int n, offset, dir = 255, i = -1, age_ms;
+    /* initial velocity: a low-offset, valid velocity */
+    float iveloc = 0, res = 0, tmp, vdiff;
+    float vfac =  vel->corr_mul * vel->const_acceleration; /* premultiply */
+    /* loop from current to older data */
+    for(offset = 1; offset < vel->num_tracker; offset++){
+	n = TRACKER_INDEX(vel, offset);
+
+	age_ms = cur_t - vel->tracker[n].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 &= vel->tracker[n].dir;
+	if(dir == 0){
+	    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;
+	}
+
+	tmp = CalcTracker(vel, offset, cur_t) * vfac;
+
+	if ((iveloc == 0 || offset <= vel->initial_range) && tmp != 0) {
+	    /* set initial velocity and result */
+	    res = iveloc = tmp;
+	    i = offset;
+	} else if (iveloc != 0 && tmp != 0) {
+	    vdiff = fabs(iveloc - tmp);
+	    if (vdiff <= vel->max_diff ||
+		vdiff/(iveloc + tmp) < vel->max_rel_diff) {
+		/* we're in range with the initial velocity,
+		 * so this result is likely better
+		 * (it contains more information). */
+		res = tmp;
+		i = offset;
+	    }else{
+		/* 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",
+		            tmp, iveloc, vdiff);
+		break;
+	    }
+	}
+    }
+    if(offset == vel->num_tracker){
+	DebugAccelF("(dix prtacc) query: last tracker in effect\n");
+	i = vel->num_tracker-1;
+    }
+    if(i>=0){
+        n = TRACKER_INDEX(vel, i);
+	DebugAccelF("(dix prtacc) result: offset %i [dx: %i dy: %i diff: %i]\n",
+	            i,
+	            vel->tracker[n].dx,
+	            vel->tracker[n].dy,
+	            cur_t - vel->tracker[n].time);
+    }
+    return res;
+}
+
+#undef TRACKER_INDEX
+
+/**
+ * Perform velocity approximation based on 2D 'mickeys' (mouse motion delta).
+ * return true if non-visible state reset is suggested
+ */
+short
+ProcessVelocityData2D(
+    DeviceVelocityPtr vel,
+    int dx,
+    int dy,
+    int time)
+{
+    float 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 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 vel,
+        int dx,
+        int dy,
+        float* fdx,
+        float* fdy,
+        short do_soften)
+{
+    if (do_soften && vel->use_softening) {
+        *fdx = ApplySimpleSoftening(vel->last_dx, dx);
+        *fdy = ApplySimpleSoftening(vel->last_dy, dy);
+    } else {
+        *fdx = dx;
+        *fdy = dy;
+    }
+
+    *fdx *= vel->const_acceleration;
+    *fdy *= vel->const_acceleration;
+}
+
+/*
+ * compute the acceleration for given velocity and enforce min_acceleartion
+ */
+float
+BasicComputeAcceleration(
+    DeviceIntPtr dev,
+    DeviceVelocityPtr vel,
+    float velocity,
+    float threshold,
+    float acc){
+
+    float 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.
+ */
+static float
+ComputeAcceleration(
+    DeviceIntPtr dev,
+    DeviceVelocityPtr vel,
+    float threshold,
+    float acc){
+    float res;
+
+    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. */
+	res = BasicComputeAcceleration(
+	          dev, vel, vel->velocity, threshold, acc);
+	res += BasicComputeAcceleration(
+	          dev, vel, vel->last_velocity, threshold, acc);
+	res += 4.0f * BasicComputeAcceleration(dev, 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(dev, 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(
+    DeviceIntPtr dev,
+    DeviceVelocityPtr vel,
+    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(
+    DeviceIntPtr dev,
+    DeviceVelocityPtr vel,
+    float velocity,
+    float threshold,
+    float 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 float
+PowerProfile(
+    DeviceIntPtr dev,
+    DeviceVelocityPtr vel,
+    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 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 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(
+    DeviceIntPtr dev,
+    DeviceVelocityPtr vel,
+    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(
+    DeviceIntPtr dev,
+    DeviceVelocityPtr vel,
+    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 += 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 float
+SmoothLimitedProfile(
+    DeviceIntPtr dev,
+    DeviceVelocityPtr vel,
+    float velocity,
+    float threshold,
+    float acc)
+{
+    float 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 float
+LinearProfile(
+    DeviceIntPtr dev,
+    DeviceVelocityPtr vel,
+    float velocity,
+    float threshold,
+    float acc)
+{
+    return acc * velocity;
+}
+
+static float
+NoProfile(
+    DeviceIntPtr dev,
+    DeviceVelocityPtr vel,
+    float velocity,
+    float threshold,
+    float 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 (DeviceVelocityPtr)dev->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 dev,
+    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) dev->valuator->accelScheme.accelData;
+    float fdx, fdy, tmp; /* no need to init */
+    Bool soften = TRUE;
+
+    if (!num_valuators || !valuators || !velocitydata)
+        return;
+
+    if (velocitydata->statistics.profile_number == AccelProfileNone &&
+	velocitydata->const_acceleration == 1.0f) {
+	return; /*we're inactive anyway, so skip the whole thing.*/
+    }
+
+    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 non-visible state? */
+        if (ProcessVelocityData2D(velocitydata, dx , dy, evtime)) {
+            soften = FALSE;
+        }
+
+        if (dev->ptrfeed && dev->ptrfeed->ctrl.num) {
+            /* invoke acceleration profile to determine acceleration */
+            mult = ComputeAcceleration (dev, velocitydata,
+					dev->ptrfeed->ctrl.threshold,
+					(float)dev->ptrfeed->ctrl.num /
+					(float)dev->ptrfeed->ctrl.den);
+
+            if(mult != 1.0 || velocitydata->const_acceleration != 1.0) {
+                ApplySofteningAndConstantDeceleration( velocitydata,
+						       dx, dy,
+						       &fdx, &fdy,
+						       (mult > 1.0) && soften);
+
+                if (dx) {
+                    tmp = mult * fdx + dev->last.remainder[0];
+                    /* Since it may not be apparent: lrintf() does not offer
+                     * strong statements about rounding; however because we
+                     * process each axis conditionally, there's no danger
+                     * of a toggling remainder. Its lack of guarantees likely
+                     * makes it faster on the average target. */
+                    *px = lrintf(tmp);
+                    dev->last.remainder[0] = tmp - (float)*px;
+                }
+                if (dy) {
+                    tmp = mult * fdy + dev->last.remainder[1];
+                    *py = lrintf(tmp);
+                    dev->last.remainder[1] = tmp - (float)*py;
+                }
+                DebugAccelF("pos (%i | %i) remainders x: %.3f y: %.3f delta x:%.3f y:%.3f\n",
+                            *px, *py, dev->last.remainder[0], dev->last.remainder[1], fdx, fdy);
+            }
+        }
+    }
+    /* 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,
+    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 (dev->ptrfeed && dev->ptrfeed->ctrl.num) {
+        /* modeled from xf86Events.c */
+        if (dev->ptrfeed->ctrl.threshold) {
+            if ((abs(dx) + abs(dy)) >= dev->ptrfeed->ctrl.threshold) {
+                dev->last.remainder[0] = ((float)dx *
+                                             (float)(dev->ptrfeed->ctrl.num)) /
+                                             (float)(dev->ptrfeed->ctrl.den) +
+                                            dev->last.remainder[0];
+                if (px) {
+                    *px = (int)dev->last.remainder[0];
+                    dev->last.remainder[0] = dev->last.remainder[0] -
+                                                (float)(*px);
+                }
+
+                dev->last.remainder[1] = ((float)dy *
+                                             (float)(dev->ptrfeed->ctrl.num)) /
+                                             (float)(dev->ptrfeed->ctrl.den) +
+                                            dev->last.remainder[1];
+                if (py) {
+                    *py = (int)dev->last.remainder[1];
+                    dev->last.remainder[1] = dev->last.remainder[1] -
+                                                (float)(*py);
+                }
+            }
+        }
+        else {
+	    mult = pow((float)dx * (float)dx + (float)dy * (float)dy,
+                       ((float)(dev->ptrfeed->ctrl.num) /
+                        (float)(dev->ptrfeed->ctrl.den) - 1.0) /
+                       2.0) / 2.0;
+            if (dx) {
+                dev->last.remainder[0] = mult * (float)dx +
+                                            dev->last.remainder[0];
+                *px = (int)dev->last.remainder[0];
+                dev->last.remainder[0] = dev->last.remainder[0] -
+                                            (float)(*px);
+            }
+            if (dy) {
+                dev->last.remainder[1] = mult * (float)dy +
+                                            dev->last.remainder[1];
+                *py = (int)dev->last.remainder[1];
+                dev->last.remainder[1] = dev->last.remainder[1] -
+                                            (float)(*py);
+            }
+        }
+    }
+}