Merge branch 'smooth-scrolling' into next

5 files changed, 531 insertions, 410 deletions

diff --git a/dix/devices.c b/dix/devices.c
index ab8a648a9..64557aaf1 100644
--- a/dix/devices.c
+++ b/dix/devices.c
@@ -260,6 +260,8 @@ AddInputDevice(ClientPtr client, DeviceProc deviceProc, Bool autoStart)
 					  offsetof(DeviceIntRec, devPrivates), PRIVATE_DEVICE);
     if (!dev)
 	return (DeviceIntPtr)NULL;
+
+    dev->last.scroll = NULL;
     dev->id = devid;
     dev->public.processInputProc = ProcessOtherEvent;
     dev->public.realInputProc = ProcessOtherEvent;
@@ -939,6 +941,7 @@ CloseDevice(DeviceIntPtr dev)
 
     free(dev->deviceGrab.sync.event);
     free(dev->config_info);     /* Allocated in xf86ActivateDevice. */
+    free(dev->last.scroll);
     dev->config_info = NULL;
     dixFreeObjectWithPrivates(dev, PRIVATE_DEVICE);
 }
@@ -1277,10 +1280,19 @@ InitValuatorClassDeviceStruct(DeviceIntPtr dev, int numAxes, Atom *labels,
     if (!valc)
         return FALSE;
 
+    dev->last.scroll = valuator_mask_new(numAxes);
+    if (!dev->last.scroll)
+    {
+        free(valc);
+        return FALSE;
+    }
+
     valc->sourceid = dev->id;
     valc->motion = NULL;
     valc->first_motion = 0;
     valc->last_motion = 0;
+    valc->h_scroll_axis = -1;
+    valc->v_scroll_axis = -1;
 
     valc->numMotionEvents = numMotionEvents;
     valc->motionHintWindow = NullWindow;
diff --git a/dix/eventconvert.c b/dix/eventconvert.c
index 024f2e833..9cc177efc 100644
--- a/dix/eventconvert.c
+++ b/dix/eventconvert.c
@@ -605,6 +605,7 @@ eventToDeviceEvent(DeviceEvent *ev, xEvent **xi)
     xde->root_x         = FP1616(ev->root_x, ev->root_x_frac);
     xde->root_y         = FP1616(ev->root_y, ev->root_y_frac);
 
+    xde->flags          = ev->flags;
     if (ev->key_repeat)
         xde->flags      |= XIKeyRepeat;
 
@@ -632,8 +633,9 @@ eventToDeviceEvent(DeviceEvent *ev, xEvent **xi)
         if (BitIsOn(ev->valuators.mask, i))
         {
             SetBit(ptr, i);
-            axisval->integral = ev->valuators.data[i];
-            axisval->frac = ev->valuators.data_frac[i];
+            axisval->integral = trunc(ev->valuators.data[i]);
+            axisval->frac = (ev->valuators.data[i] - axisval->integral) *
+                            (1UL << 32);
             axisval++;
         }
     }
@@ -648,7 +650,7 @@ eventToRawEvent(RawDeviceEvent *ev, xEvent **xi)
     int vallen, nvals;
     int i, len = sizeof(xXIRawEvent);
     char *ptr;
-    FP3232 *axisval;
+    FP3232 *axisval, *axisval_raw;
 
     nvals = count_bits(ev->valuators.mask, sizeof(ev->valuators.mask));
     len += nvals * sizeof(FP3232) * 2; /* 8 byte per valuator, once
@@ -666,19 +668,23 @@ eventToRawEvent(RawDeviceEvent *ev, xEvent **xi)
     raw->detail         = ev->detail.button;
     raw->deviceid       = ev->deviceid;
     raw->valuators_len  = vallen;
+    raw->flags          = ev->flags;
 
     ptr = (char*)&raw[1];
     axisval = (FP3232*)(ptr + raw->valuators_len * 4);
+    axisval_raw = axisval + nvals;
     for (i = 0; i < sizeof(ev->valuators.mask) * 8; i++)
     {
         if (BitIsOn(ev->valuators.mask, i))
         {
             SetBit(ptr, i);
-            axisval->integral = ev->valuators.data[i];
-            axisval->frac = ev->valuators.data_frac[i];
-            (axisval + nvals)->integral = ev->valuators.data_raw[i];
-            (axisval + nvals)->frac = ev->valuators.data_raw_frac[i];
+            axisval->integral = trunc(ev->valuators.data[i]);
+            axisval->frac = ev->valuators.data[i] - axisval->integral;
+            axisval_raw->integral = trunc(ev->valuators.data_raw[i]);
+            axisval_raw->frac = ev->valuators.data_raw[i] -
+                                axisval_raw->integral;
             axisval++;
+            axisval_raw++;
         }
     }
 
diff --git a/dix/getevents.c b/dix/getevents.c
index be2840c47..c42971592 100644
--- a/dix/getevents.c
+++ b/dix/getevents.c
@@ -2,6 +2,7 @@
  * Copyright © 2006 Nokia Corporation
  * Copyright © 2006-2007 Daniel Stone
  * Copyright © 2008 Red Hat, Inc.
+ * Copyright © 2011 The Chromium Authors
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -58,6 +59,7 @@
 #endif
 
 #include <X11/extensions/XI.h>
+#include <X11/extensions/XI2.h>
 #include <X11/extensions/XIproto.h>
 #include <pixman.h>
 #include "exglobals.h"
@@ -167,7 +169,7 @@ init_raw(DeviceIntPtr dev, RawDeviceEvent *event, Time ms, int type, int detail)
 }
 
 static void
-set_raw_valuators(RawDeviceEvent *event, ValuatorMask *mask, int32_t* data)
+set_raw_valuators(RawDeviceEvent *event, ValuatorMask *mask, double* data)
 {
     int i;
 
@@ -176,7 +178,7 @@ set_raw_valuators(RawDeviceEvent *event, ValuatorMask *mask, int32_t* data)
         if (valuator_mask_isset(mask, i))
         {
             SetBit(event->valuators.mask, i);
-            data[i] = valuator_mask_get(mask, i);
+            data[i] = valuator_mask_get_double(mask, i);
         }
     }
 }
@@ -196,9 +198,7 @@ set_valuators(DeviceIntPtr dev, DeviceEvent* event, ValuatorMask *mask)
             SetBit(event->valuators.mask, i);
             if (valuator_get_mode(dev, i) == Absolute)
                 SetBit(event->valuators.mode, i);
-            event->valuators.data[i] = valuator_mask_get(mask, i);
-            event->valuators.data_frac[i] =
-                dev->last.remainder[i] * (1 << 16) * (1 << 16);
+            event->valuators.data[i] = valuator_mask_get_double(mask, i);
         }
         else if (valuator_get_mode(dev, i) == Absolute)
             event->valuators.data[i] = dev->valuator->axisVal[i];
@@ -255,39 +255,29 @@ CreateClassesChangedEvent(InternalEvent* event,
 /**
  * Rescale the coord between the two axis ranges.
  */
-static int
-rescaleValuatorAxis(int coord, float remainder, float *remainder_return, AxisInfoPtr from, AxisInfoPtr to,
-                    int defmax)
+static double
+rescaleValuatorAxis(double coord, AxisInfoPtr from, AxisInfoPtr to,
+                    double defmax)
 {
-    int fmin = 0, tmin = 0, fmax = defmax, tmax = defmax, coord_return;
-    float value;
+    double fmin = 0.0, fmax = defmax;
+    double tmin = 0.0, tmax = defmax;
 
-    if(from && from->min_value < from->max_value) {
+    if (from && from->min_value < from->max_value) {
         fmin = from->min_value;
         fmax = from->max_value;
     }
-    if(to && to->min_value < to->max_value) {
+    if (to && to->min_value < to->max_value) {
         tmin = to->min_value;
         tmax = to->max_value;
     }
 
-    if(fmin == tmin && fmax == tmax) {
-        if (remainder_return)
-            *remainder_return = remainder;
+    if (fmin == tmin && fmax == tmax)
         return coord;
-    }
 
-    if(fmax == fmin) { /* avoid division by 0 */
-        if (remainder_return)
-            *remainder_return = 0.0;
-        return 0;
-    }
+    if (fmax == fmin) /* avoid division by 0 */
+        return 0.0;
 
-    value = (coord + remainder - fmin) * (tmax - tmin) / (fmax - fmin) + tmin;
-    coord_return = lroundf(value);
-    if (remainder_return)
-        *remainder_return = value - coord_return;
-    return coord_return;
+    return (coord - fmin) * (tmax - tmin) / (fmax - fmin) + tmin;
 }
 
 /**
@@ -309,19 +299,25 @@ updateSlaveDeviceCoords(DeviceIntPtr master, DeviceIntPtr pDev)
      * position of the pointer */
     pDev->last.valuators[0] = master->last.valuators[0];
     pDev->last.valuators[1] = master->last.valuators[1];
-    pDev->last.remainder[0] = master->last.remainder[0];
-    pDev->last.remainder[1] = master->last.remainder[1];
 
     if (!pDev->valuator)
         return;
 
     /* scale back to device coordinates */
     if(pDev->valuator->numAxes > 0)
-        pDev->last.valuators[0] = rescaleValuatorAxis(pDev->last.valuators[0], pDev->last.remainder[0],
-                        &pDev->last.remainder[0], NULL, pDev->valuator->axes + 0, scr->width);
+    {
+        pDev->last.valuators[0] = rescaleValuatorAxis(pDev->last.valuators[0],
+                                                      NULL,
+                                                      pDev->valuator->axes + 0,
+                                                      scr->width);
+    }
     if(pDev->valuator->numAxes > 1)
-        pDev->last.valuators[1] = rescaleValuatorAxis(pDev->last.valuators[1], pDev->last.remainder[1],
-                        &pDev->last.remainder[1], NULL, pDev->valuator->axes + 1, scr->height);
+    {
+        pDev->last.valuators[1] = rescaleValuatorAxis(pDev->last.valuators[1],
+                                                      NULL,
+                                                      pDev->valuator->axes + 1,
+                                                      scr->height);
+    }
 
     /* calculate the other axis as well based on info from the old
      * slave-device. If the old slave had less axes than this one,
@@ -332,16 +328,13 @@ updateSlaveDeviceCoords(DeviceIntPtr master, DeviceIntPtr pDev)
             if (i >= lastSlave->valuator->numAxes)
             {
                 pDev->last.valuators[i] = 0;
-                pDev->last.remainder[i] = 0;
             }
             else
             {
-                pDev->last.valuators[i] =
-                    rescaleValuatorAxis(pDev->last.valuators[i],
-                            pDev->last.remainder[i],
-                            &pDev->last.remainder[i],
-                            lastSlave->valuator->axes + i,
-                            pDev->valuator->axes + i, 0);
+                double val = pDev->last.valuators[i];
+                val = rescaleValuatorAxis(val, lastSlave->valuator->axes + i,
+                                          pDev->valuator->axes + i, 0);
+                pDev->last.valuators[i] = val;
             }
         }
     }
@@ -452,7 +445,7 @@ GetMotionHistory(DeviceIntPtr pDev, xTimecoord **buff, unsigned long start,
                 /* scale to screen coords */
                 to = &core_axis;
                 to->max_value = pScreen->width;
-                coord = rescaleValuatorAxis(coord, 0.0, NULL, &from, to, pScreen->width);
+                coord = rescaleValuatorAxis(coord, &from, to, pScreen->width);
 
                 memcpy(corebuf, &coord, sizeof(INT16));
                 corebuf++;
@@ -463,7 +456,7 @@ GetMotionHistory(DeviceIntPtr pDev, xTimecoord **buff, unsigned long start,
                 memcpy(&coord, icbuf++, sizeof(INT32));
 
                 to->max_value = pScreen->height;
-                coord = rescaleValuatorAxis(coord, 0.0, NULL, &from, to, pScreen->height);
+                coord = rescaleValuatorAxis(coord, &from, to, pScreen->height);
                 memcpy(corebuf, &coord, sizeof(INT16));
 
             } else if (IsMaster(pDev))
@@ -491,7 +484,7 @@ GetMotionHistory(DeviceIntPtr pDev, xTimecoord **buff, unsigned long start,
                         from.max_value = pScreen->height;
 
                     /* scale from stored range into current range */
-                    coord = rescaleValuatorAxis(coord, 0.0, NULL, &from, to, 0);
+                    coord = rescaleValuatorAxis(coord, &from, to, 0);
                     memcpy(ocbuf, &coord, sizeof(INT32));
                     ocbuf++;
                 }
@@ -525,7 +518,7 @@ GetMotionHistory(DeviceIntPtr pDev, xTimecoord **buff, unsigned long start,
  */
 static void
 updateMotionHistory(DeviceIntPtr pDev, CARD32 ms, ValuatorMask *mask,
-                    int *valuators)
+                    double *valuators)
 {
     char *buff = (char *) pDev->valuator->motion;
     ValuatorClassPtr v;
@@ -547,6 +540,7 @@ updateMotionHistory(DeviceIntPtr pDev, CARD32 ms, ValuatorMask *mask,
 
         for (i = 0; i < v->numAxes; i++)
         {
+            int val;
             /* XI1 doesn't support mixed mode devices */
             if (valuator_get_mode(pDev, i) != valuator_get_mode(pDev, 0))
                 break;
@@ -559,7 +553,8 @@ updateMotionHistory(DeviceIntPtr pDev, CARD32 ms, ValuatorMask *mask,
             buff += sizeof(INT32);
             memcpy(buff, &v->axes[i].max_value, sizeof(INT32));
             buff += sizeof(INT32);
-            memcpy(buff, &valuators[i], sizeof(INT32));
+            val = valuators[i];
+            memcpy(buff, &val, sizeof(INT32));
             buff += sizeof(INT32);
         }
     } else
@@ -575,12 +570,14 @@ updateMotionHistory(DeviceIntPtr pDev, CARD32 ms, ValuatorMask *mask,
 
         for (i = 0; i < MAX_VALUATORS; i++)
         {
+            int val;
             if (valuator_mask_size(mask) <= i || !valuator_mask_isset(mask, i))
             {
                 buff += sizeof(INT32);
                 continue;
             }
-            memcpy(buff, &valuators[i], sizeof(INT32));
+            val = valuators[i];
+            memcpy(buff, &val, sizeof(INT32));
             buff += sizeof(INT32);
         }
     }
@@ -607,8 +604,10 @@ GetMaximumEventsNum(void) {
     /* One raw event
      * One device event
      * One possible device changed event
+     * Lots of possible separate button scroll events (horiz + vert)
+     * Lots of possible separate raw button scroll events (horiz + vert)
      */
-    return 3;
+    return 100;
 }
 
 
@@ -617,7 +616,7 @@ GetMaximumEventsNum(void) {
  * InitValuatorAxisClassStruct.
  */
 static void
-clipAxis(DeviceIntPtr pDev, int axisNum, int *val)
+clipAxis(DeviceIntPtr pDev, int axisNum, double *val)
 {
     AxisInfoPtr axis;
 
@@ -647,9 +646,9 @@ clipValuators(DeviceIntPtr pDev, ValuatorMask *mask)
     for (i = 0; i < valuator_mask_size(mask); i++)
         if (valuator_mask_isset(mask, i))
         {
-            int val = valuator_mask_get(mask, i);
+            double val = valuator_mask_get_double(mask, i);
             clipAxis(pDev, i, &val);
-            valuator_mask_set(mask, i, val);
+            valuator_mask_set_double(mask, i, val);
         }
 }
 
@@ -690,85 +689,52 @@ UpdateFromMaster(InternalEvent* events, DeviceIntPtr dev, int type, int *num_eve
 /**
  * Move the device's pointer to the position given in the valuators.
  *
- * @param dev The device which's pointer is to be moved.
- * @param x Returns the x position of the pointer after the move.
- * @param y Returns the y position of the pointer after the move.
- * @param mask Bit mask of valid valuators.
- * @param valuators Valuator data for each axis between @first and
- *        @first+@num.
+ * @param dev The device whose pointer is to be moved.
+ * @param mask Valuator data for this event.
  */
 static void
-moveAbsolute(DeviceIntPtr dev, int *x, int *y, ValuatorMask *mask)
+moveAbsolute(DeviceIntPtr dev, ValuatorMask *mask)
 {
     int i;
 
-    if (valuator_mask_isset(mask, 0))
-        *x = valuator_mask_get(mask, 0);
-    else
-        *x = dev->last.valuators[0];
-
-    if (valuator_mask_isset(mask, 1))
-        *y = valuator_mask_get(mask, 1);
-    else
-        *y = dev->last.valuators[1];
-
-    clipAxis(dev, 0, x);
-    clipAxis(dev, 1, y);
-
-    for (i = 2; i < valuator_mask_size(mask); i++)
+    for (i = 0; i < valuator_mask_size(mask); i++)
     {
-        if (valuator_mask_isset(mask, i))
-        {
-            dev->last.valuators[i] = valuator_mask_get(mask, i);
-            clipAxis(dev, i, &dev->last.valuators[i]);
-        }
+        double val;
+
+        if (!valuator_mask_isset(mask, i))
+            continue;
+        val = valuator_mask_get_double(mask, i);
+        clipAxis(dev, i, &val);
+        valuator_mask_set_double(mask, i, val);
     }
 }
 
 /**
  * Move the device's pointer by the values given in @valuators.
  *
- * @param dev The device which's pointer is to be moved.
- * @param x Returns the x position of the pointer after the move.
- * @param y Returns the y position of the pointer after the move.
- * @param mask Bit mask of valid valuators.
- * @param valuators Valuator data for each axis between @first and
- *        @first+@num.
+ * @param dev The device whose pointer is to be moved.
+ * @param mask Valuator data for this event.
  */
 static void
-moveRelative(DeviceIntPtr dev, int *x, int *y, ValuatorMask *mask)
+moveRelative(DeviceIntPtr dev, ValuatorMask *mask)
 {
     int i;
-
-    *x = dev->last.valuators[0];
-    *y = dev->last.valuators[1];
-
-    if (valuator_mask_isset(mask, 0))
-        *x += valuator_mask_get(mask, 0);
-
-    if (valuator_mask_isset(mask, 1))
-        *y += valuator_mask_get(mask, 1);
-
-    /* if attached, clip both x and y to the defined limits (usually
-     * co-ord space limit). If it is attached, we need x/y to go over the
-     * limits to be able to change screens. */
-    if (dev->valuator && (IsMaster(dev) || !IsFloating(dev))) {
-        if (valuator_get_mode(dev, 0) == Absolute)
-            clipAxis(dev, 0, x);
-        if (valuator_get_mode(dev, 1) == Absolute)
-            clipAxis(dev, 1, y);
-    }
+    Bool clip_xy = IsMaster(dev) || !IsFloating(dev);
 
     /* calc other axes, clip, drop back into valuators */
-    for (i = 2; i < valuator_mask_size(mask); i++)
+    for (i = 0; i < valuator_mask_size(mask); i++)
     {
-        if (valuator_mask_isset(mask, i))
-        {
-            dev->last.valuators[i] += valuator_mask_get(mask, i);
-            if (valuator_get_mode(dev, i) == Absolute)
-                clipAxis(dev, i, &dev->last.valuators[i]);
-            valuator_mask_set(mask, i, dev->last.valuators[i]);
-        }
+        double val = dev->last.valuators[i];
+
+        if (!valuator_mask_isset(mask, i))
+            continue;
+        val += valuator_mask_get_double(mask, i);
+        /* x & y need to go over the limits to cross screens if the SD
+         * isn't currently attached; otherwise, clip to screen bounds. */
+        if (valuator_get_mode(dev, i) == Absolute &&
+            ((i != 0 && i != 1) || clip_xy))
+            clipAxis(dev, i, &val);
+        valuator_mask_set_double(mask, i, val);
     }
 }
 
@@ -799,89 +765,68 @@ accelPointer(DeviceIntPtr dev, ValuatorMask* valuators, CARD32 ms)
  *
  * @param dev The device to be moved.
  * @param mode Movement mode (Absolute or Relative)
- * @param x Pointer to current x-axis value, may be modified.
- * @param y Pointer to current y-axis value, may be modified.
- * @param x_frac Fractional part of current x-axis value, may be modified.
- * @param y_frac Fractional part of current y-axis value, may be modified.
  * @param scr Screen the device's sprite is currently on.
+ * @param mask Mask of axis values for this event
  * @param screenx Screen x coordinate the sprite is on after the update.
  * @param screeny Screen y coordinate the sprite is on after the update.
- * @param screenx_frac Fractional part of screen x coordinate, as above.
- * @param screeny_frac Fractional part of screen y coordinate, as above.
  */
 static void
-positionSprite(DeviceIntPtr dev, int mode,
-               int *x, int *y, float x_frac, float y_frac,
-               ScreenPtr scr, int *screenx, int *screeny, float *screenx_frac, float *screeny_frac)
+positionSprite(DeviceIntPtr dev, int mode, ScreenPtr scr, ValuatorMask *mask,
+               double *screenx, double *screeny)
 {
-    int old_screenx, old_screeny;
+    int isx, isy; /* screen {x, y}, in int */
+    double x, y;
 
-    /* scale x&y to screen */
-    if (dev->valuator && dev->valuator->numAxes > 0) {
-        *screenx = rescaleValuatorAxis(*x, x_frac, screenx_frac,
-                dev->valuator->axes + 0, NULL, scr->width);
-    } else {
-        *screenx = dev->last.valuators[0];
-        *screenx_frac = dev->last.remainder[0];
-    }
+    if (!dev->valuator || dev->valuator->numAxes < 2)
+        return;
 
-    if (dev->valuator && dev->valuator->numAxes > 1) {
-        *screeny = rescaleValuatorAxis(*y, y_frac, screeny_frac,
-                dev->valuator->axes + 1, NULL, scr->height);
-    } else {
-        *screeny = dev->last.valuators[1];
-        *screeny_frac = dev->last.remainder[1];
-    }
+    if (valuator_mask_isset(mask, 0))
+        x = valuator_mask_get_double(mask, 0);
+    else
+        x = dev->last.valuators[0];
+    if (valuator_mask_isset(mask, 1))
+        y = valuator_mask_get_double(mask, 1);
+    else
+        y = dev->last.valuators[1];
 
-    /* Hit the left screen edge? */
-    if (*screenx <= 0 && *screenx_frac < 0.0f)
+    /* scale x&y to screen */
+    *screenx = rescaleValuatorAxis(x, dev->valuator->axes + 0, NULL,
+                                   scr->width);
+    *screeny = rescaleValuatorAxis(y, dev->valuator->axes + 1, NULL,
+                                   scr->height);
+
+    /* miPointerSetPosition takes care of crossing screens for us, as well as
+     * clipping to the current screen.  In the event we actually change screen,
+     * we just drop the float component on the floor, then convert from
+     * screenx back into device co-ordinates. */
+    isx = trunc(*screenx);
+    isy = trunc(*screeny);
+    miPointerSetPosition(dev, mode, &isx, &isy);
+    scr = miPointerGetScreen(dev);
+    if (isx != trunc(*screenx))
     {
-        *screenx_frac = 0.0f;
-        x_frac = 0.0f;
+        *screenx -= trunc(*screenx) - isx;
+        x = rescaleValuatorAxis(*screenx, NULL, dev->valuator->axes + 0,
+                                scr->width);
     }
-    if (*screeny <= 0 && *screeny_frac < 0.0f)
+    if (isy != trunc(*screeny))
     {
-        *screeny_frac = 0.0f;
-        y_frac = 0.0f;
+        *screeny -= trunc(*screeny) - isy;
+        y = rescaleValuatorAxis(*screeny, NULL, dev->valuator->axes + 1,
+                                scr->height);
     }
 
-
-    old_screenx = *screenx;
-    old_screeny = *screeny;
-    /* This takes care of crossing screens for us, as well as clipping
-     * to the current screen. */
-    miPointerSetPosition(dev, mode, screenx, screeny);
-
-    if(!IsMaster(dev) && !IsFloating(dev)) {
+    /* Update the MD's co-ordinates, which are always in screen space. */
+    if (!IsMaster(dev) || !IsFloating(dev)) {
         DeviceIntPtr master = GetMaster(dev, MASTER_POINTER);
         master->last.valuators[0] = *screenx;
         master->last.valuators[1] = *screeny;
-        master->last.remainder[0] = *screenx_frac;
-        master->last.remainder[1] = *screeny_frac;
-    }
-
-    if (dev->valuator)
-    {
-        /* Crossed screen? Scale back to device coordiantes */
-        if(*screenx != old_screenx)
-        {
-            scr = miPointerGetScreen(dev);
-            *x = rescaleValuatorAxis(*screenx, *screenx_frac, &x_frac, NULL,
-                                    dev->valuator->axes + 0, scr->width);
-        }
-        if(*screeny != old_screeny)
-        {
-            scr = miPointerGetScreen(dev);
-            *y = rescaleValuatorAxis(*screeny, *screeny_frac, &y_frac, NULL,
-                                     dev->valuator->axes + 1, scr->height);
-        }
     }
 
-    /* dropy x/y (device coordinates) back into valuators for next event */
-    dev->last.valuators[0] = *x;
-    dev->last.valuators[1] = *y;
-    dev->last.remainder[0] = x_frac;
-    dev->last.remainder[1] = y_frac;
+    if (valuator_mask_isset(mask, 0))
+        valuator_mask_set_double(mask, 0, x);
+    if (valuator_mask_isset(mask, 1))
+        valuator_mask_set_double(mask, 1, y);
 }
 
 /**
@@ -1045,32 +990,37 @@ FreeEventList(InternalEvent *list, int num_events)
  * back into x/y.
  */
 static void
-transform(struct pixman_f_transform *m, int *x, int *y)
+transform(struct pixman_f_transform *m, double *x, double *y)
 {
     struct pixman_f_vector p = {.v = {*x, *y, 1}};
     pixman_f_transform_point(m, &p);
 
-    *x = lround(p.v[0]);
-    *y = lround(p.v[1]);
+    *x = p.v[0];
+    *y = p.v[1];
 }
 
 static void
 transformAbsolute(DeviceIntPtr dev, ValuatorMask *mask)
 {
-    int x, y, ox, oy;
+    double x, y, ox, oy;
+
+    if (valuator_mask_isset(mask, 0))
+        ox = x = valuator_mask_get_double(mask, 0);
+    else
+        ox = x = dev->last.valuators[0];
 
-    ox = x = valuator_mask_isset(mask, 0) ? valuator_mask_get(mask, 0) :
-                                            dev->last.valuators[0];
-    oy = y = valuator_mask_isset(mask, 1) ? valuator_mask_get(mask, 1) :
-                                            dev->last.valuators[1];
+    if (valuator_mask_isset(mask, 1))
+        oy = y = valuator_mask_get_double(mask, 1);
+    else
+        oy = y = dev->last.valuators[1];
 
     transform(&dev->transform, &x, &y);
 
     if (valuator_mask_isset(mask, 0) || ox != x)
-        valuator_mask_set(mask, 0, x);
+        valuator_mask_set_double(mask, 0, x);
 
     if (valuator_mask_isset(mask, 1) || oy != y)
-        valuator_mask_set(mask, 1, y);
+        valuator_mask_set_double(mask, 1, y);
 }
 
 /**
@@ -1097,42 +1047,25 @@ QueuePointerEvents(DeviceIntPtr device, int type,
 }
 
 /**
- * Generate a series of InternalEvents representing pointer motion, or
- * button presses.
- *
- * The DDX is responsible for allocating the events in the first
- * place via InitEventList() and GetMaximumEventsNum(), and for freeing it.
- *
- * In the generated events rootX/Y will be in absolute screen coords and
- * the valuator information in the absolute or relative device coords.
- *
- * last.valuators[x] of the device is always in absolute device coords.
- * last.valuators[x] of the master device is in absolute screen coords.
+ * Helper function for GetPointerEvents, which only generates motion and
+ * raw motion events for the slave device: does not update the master device.
  *
- * master->last.valuators[x] for x > 2 is undefined.
+ * Should not be called by anyone other than GetPointerEvents.
  *
  * @return the number of events written into events.
  */
-int
-GetPointerEvents(InternalEvent *events, DeviceIntPtr pDev, int type, int buttons,
-                 int flags, const ValuatorMask *mask_in) {
-    int num_events = 1;
-    CARD32 ms;
+static int
+fill_pointer_events(InternalEvent *events, DeviceIntPtr pDev, int type,
+                    int buttons, CARD32 ms, int flags,
+                    const ValuatorMask *mask_in)
+{
+    int num_events = 1, i;
     DeviceEvent *event;
-    RawDeviceEvent    *raw;
-    int x = 0, y = 0, /* device coords */
-        cx, cy; /* only screen coordinates */
-    float x_frac = 0.0, y_frac = 0.0, cx_frac, cy_frac;
+    RawDeviceEvent *raw;
+    double screenx = 0.0, screeny = 0.0;
     ScreenPtr scr = miPointerGetScreen(pDev);
     ValuatorMask mask;
 
-    /* refuse events from disabled devices */
-    if (!pDev->enabled)
-        return 0;
-
-    if (!scr)
-        return 0;
-
     switch (type)
     {
         case MotionNotify:
@@ -1148,10 +1081,6 @@ GetPointerEvents(InternalEvent *events, DeviceIntPtr pDev, int type, int buttons
             return 0;
     }
 
-    ms = GetTimeInMillis(); /* before pointer update to help precision */
-
-    events = UpdateFromMaster(events, pDev, DEVCHANGE_POINTER_EVENT, &num_events);
-
     valuator_mask_copy(&mask, mask_in);
 
     if ((flags & POINTER_NORAW) == 0)
@@ -1161,61 +1090,54 @@ GetPointerEvents(InternalEvent *events, DeviceIntPtr pDev, int type, int buttons
 	num_events++;
 
 	init_raw(pDev, raw, ms, type, buttons);
-	set_raw_valuators(raw, &mask, raw->valuators.data_raw);
+        set_raw_valuators(raw, &mask, raw->valuators.data_raw);
     }
 
     if (flags & POINTER_ABSOLUTE)
     {
         if (flags & POINTER_SCREEN) /* valuators are in screen coords */
         {
-            int scaled;
+            double scaled;
 
             if (valuator_mask_isset(&mask, 0))
             {
-                scaled = rescaleValuatorAxis(valuator_mask_get(&mask, 0),
-                                             0.0, &x_frac, NULL,
-                                             pDev->valuator->axes + 0,
+                scaled = rescaleValuatorAxis(valuator_mask_get_double(&mask, 0),
+                                             NULL, pDev->valuator->axes + 0,
                                              scr->width);
-                valuator_mask_set(&mask, 0, scaled);
+                valuator_mask_set_double(&mask, 0, scaled);
             }
             if (valuator_mask_isset(&mask, 1))
             {
-                scaled = rescaleValuatorAxis(valuator_mask_get(&mask, 1),
-                                             0.0, &y_frac, NULL,
-                                             pDev->valuator->axes + 1,
+                scaled = rescaleValuatorAxis(valuator_mask_get_double(&mask, 1),
+                                             NULL, pDev->valuator->axes + 1,
                                              scr->height);
-                valuator_mask_set(&mask, 1, scaled);
+                valuator_mask_set_double(&mask, 1, scaled);
             }
         }
 
         transformAbsolute(pDev, &mask);
-        moveAbsolute(pDev, &x, &y, &mask);
+        moveAbsolute(pDev, &mask);
     } else {
-        if (flags & POINTER_ACCELERATE) {
+        if (flags & POINTER_ACCELERATE)
             accelPointer(pDev, &mask, ms);
-            /* The pointer acceleration code modifies the fractional part
-             * in-place, so we need to extract this information first */
-            x_frac = pDev->last.remainder[0];
-            y_frac = pDev->last.remainder[1];
-        }
-        moveRelative(pDev, &x, &y, &mask);
+        moveRelative(pDev, &mask);
     }
 
     if ((flags & POINTER_NORAW) == 0)
-	set_raw_valuators(raw, &mask, raw->valuators.data);
+        set_raw_valuators(raw, &mask, raw->valuators.data);
 
-    positionSprite(pDev, (flags & POINTER_ABSOLUTE) ? Absolute : Relative,
-                   &x, &y, x_frac, y_frac, scr, &cx, &cy, &cx_frac, &cy_frac);
+    positionSprite(pDev, (flags & POINTER_ABSOLUTE) ? Absolute : Relative, scr,
+                   &mask, &screenx, &screeny);
     updateHistory(pDev, &mask, ms);
 
-    /* Update the valuators with the true value sent to the client*/
-    if (valuator_mask_isset(&mask, 0))
-        valuator_mask_set(&mask, 0, x);
-    if (valuator_mask_isset(&mask, 1))
-        valuator_mask_set(&mask, 1, y);
-
     clipValuators(pDev, &mask);
 
+    for (i = 0; i < valuator_mask_size(&mask); i++)
+    {
+        if (valuator_mask_isset(&mask, i))
+            pDev->last.valuators[i] = valuator_mask_get_double(&mask, i);
+    }
+
     event = &events->device_event;
     init_device_event(event, pDev, ms);
 
@@ -1235,10 +1157,16 @@ GetPointerEvents(InternalEvent *events, DeviceIntPtr pDev, int type, int buttons
         event->detail.button = buttons;
     }
 
-    event->root_x = cx; /* root_x/y always in screen coords */
-    event->root_y = cy;
-    event->root_x_frac = cx_frac;
-    event->root_y_frac = cy_frac;
+    /* root_x and root_y must be in screen co-ordinates */
+    event->root_x = trunc(screenx);
+    event->root_y = trunc(screeny);
+    event->root_x_frac = screenx - trunc(screenx);
+    event->root_y_frac = screeny - trunc(screeny);
+
+    if (flags & POINTER_EMULATED) {
+        raw->flags = XIPointerEmulated;
+        event->flags = XIPointerEmulated;
+    }
 
     set_valuators(pDev, event, &mask);
 
@@ -1246,6 +1174,204 @@ GetPointerEvents(InternalEvent *events, DeviceIntPtr pDev, int type, int buttons
 }
 
 /**
+ * Generate events for each scroll axis that changed between before/after
+ * for the device.
+ *
+ * @param events The pointer to the event list to fill the events
+ * @param dev The device to generate the events for
+ * @param axis The axis number to generate events for
+ * @param mask State before this event in absolute coords
+ * @param[in,out] last Last scroll state posted in absolute coords (modified
+ * in-place)
+ * @param ms Current time in ms
+ * @param max_events Max number of events to be generated
+ * @return The number of events generated
+ */
+static int
+emulate_scroll_button_events(InternalEvent *events,
+                             DeviceIntPtr dev,
+                             int axis,
+                             const ValuatorMask *mask,
+                             ValuatorMask *last,
+                             CARD32 ms,
+                             int max_events)
+{
+    AxisInfoPtr ax;
+    double delta;
+    double incr;
+    int num_events = 0;
+    double total;
+    int b;
+
+    if (dev->valuator->axes[axis].scroll.type == SCROLL_TYPE_NONE)
+        return 0;
+
+    if (!valuator_mask_isset(mask, axis))
+        return 0;
+
+    ax = &dev->valuator->axes[axis];
+    incr = ax->scroll.increment;
+
+    if (!valuator_mask_isset(last, axis))
+        valuator_mask_set_double(last, axis, 0);
+
+    delta = valuator_mask_get_double(mask, axis) - valuator_mask_get_double(last, axis);
+    total = delta;
+    b = (ax->scroll.type == SCROLL_TYPE_VERTICAL) ? 5 : 7;
+
+    if ((incr > 0 && delta < 0) ||
+        (incr < 0 && delta > 0))
+        b--; /* we're scrolling up or left → button 4 or 6 */
+
+    while (fabs(delta) >= fabs(incr))
+    {
+        int nev_tmp;
+
+        if (delta > 0)
+            delta -= fabs(incr);
+        else if (delta < 0)
+            delta += fabs(incr);
+
+        /* fill_pointer_events() generates four events: one normal and one raw
+         * event for button press and button release.
+         * We may get a bigger scroll delta than we can generate events
+         * for. In that case, we keep decreasing delta, but skip events.
+         */
+        if (num_events + 4 < max_events)
+        {
+            nev_tmp = fill_pointer_events(events, dev, ButtonPress, b, ms,
+                                          POINTER_EMULATED, NULL);
+            events += nev_tmp;
+            num_events += nev_tmp;
+            nev_tmp = fill_pointer_events(events, dev, ButtonRelease, b, ms,
+                                          POINTER_EMULATED, NULL);
+            events += nev_tmp;
+            num_events += nev_tmp;
+        }
+    }
+
+    /* We emulated, update last.scroll */
+    if (total != delta)
+    {
+        total -= delta;
+        valuator_mask_set_double(last, axis,
+                                 valuator_mask_get_double(last, axis) + total);
+    }
+
+    return num_events;
+}
+
+
+/**
+ * Generate a complete series of InternalEvents (filled into the EventList)
+ * representing pointer motion, or button presses.  If the device is a slave
+ * device, also potentially generate a DeviceClassesChangedEvent to update
+ * the master device.
+ *
+ * events is not NULL-terminated; the return value is the number of events.
+ * The DDX is responsible for allocating the event structure in the first
+ * place via InitEventList() and GetMaximumEventsNum(), and for freeing it.
+ *
+ * In the generated events rootX/Y will be in absolute screen coords and
+ * the valuator information in the absolute or relative device coords.
+ *
+ * last.valuators[x] of the device is always in absolute device coords.
+ * last.valuators[x] of the master device is in absolute screen coords.
+ *
+ * master->last.valuators[x] for x > 2 is undefined.
+ */
+int
+GetPointerEvents(InternalEvent *events, DeviceIntPtr pDev, int type,
+                 int buttons, int flags, const ValuatorMask *mask_in)
+{
+    CARD32 ms = GetTimeInMillis();
+    int num_events = 0, nev_tmp;
+    int h_scroll_axis = pDev->valuator->h_scroll_axis;
+    int v_scroll_axis = pDev->valuator->v_scroll_axis;
+    ValuatorMask mask;
+    ValuatorMask scroll;
+    int i;
+
+    /* refuse events from disabled devices */
+    if (!pDev->enabled)
+        return 0;
+
+    if (!miPointerGetScreen(pDev))
+        return 0;
+
+    events = UpdateFromMaster(events, pDev, DEVCHANGE_POINTER_EVENT,
+                              &num_events);
+
+    valuator_mask_copy(&mask, mask_in);
+
+    /* Turn a scroll button press into a smooth-scrolling event if
+     * necessary. This only needs to cater for the XIScrollFlagPreferred
+     * axis (if more than one scrolling axis is present) */
+    if (type == ButtonPress)
+    {
+        double val, adj;
+        int axis;
+
+        switch (buttons) {
+        case 4:
+            adj = 1.0;
+            axis = v_scroll_axis;
+            break;
+        case 5:
+            adj = -1.0;
+            axis = v_scroll_axis;
+            break;
+        case 6:
+            adj = 1.0;
+            axis = h_scroll_axis;
+            break;
+        case 7:
+            adj = -1.0;
+            axis = h_scroll_axis;
+            break;
+        default:
+            adj = 0.0;
+            axis = -1;
+            break;
+        }
+
+        if (adj != 0.0 && axis != -1)
+        {
+            adj *= pDev->valuator->axes[axis].scroll.increment;
+            val = valuator_mask_get_double(&mask, axis) + adj;
+            valuator_mask_set_double(&mask, axis, val);
+            type = MotionNotify;
+            buttons = 0;
+        }
+    }
+
+    /* First fill out the original event set, with smooth-scrolling axes. */
+    nev_tmp = fill_pointer_events(events, pDev, type, buttons, ms, flags,
+                                  &mask);
+    events += nev_tmp;
+    num_events += nev_tmp;
+
+    valuator_mask_zero(&scroll);
+
+    /* Now turn the smooth-scrolling axes back into emulated button presses
+     * for legacy clients, based on the integer delta between before and now */
+    for (i = 0; i < valuator_mask_size(&mask); i++) {
+        if (!valuator_mask_isset(&mask, i))
+            continue;
+
+        valuator_mask_set_double(&scroll, i, pDev->last.valuators[i]);
+
+        nev_tmp = emulate_scroll_button_events(events, pDev, i, &scroll,
+                                               pDev->last.scroll, ms,
+                                               GetMaximumEventsNum() - num_events);
+        events += nev_tmp;
+        num_events += nev_tmp;
+    }
+
+    return num_events;
+}
+
+/**
  * Generate internal events representing this proximity event and enqueue
  * them on the event queue.
  *
diff --git a/dix/inpututils.c b/dix/inpututils.c
index 7aeb1e516..0a3d3d8b4 100644
--- a/dix/inpututils.c
+++ b/dix/inpututils.c
@@ -497,10 +497,10 @@ valuator_mask_isset(const ValuatorMask *mask, int valuator)
 }
 
 /**
- * Set the valuator to the given data.
+ * Set the valuator to the given floating-point data.
  */
 void
-valuator_mask_set(ValuatorMask *mask, int valuator, int data)
+valuator_mask_set_double(ValuatorMask *mask, int valuator, double data)
 {
     mask->last_bit = max(valuator, mask->last_bit);
     SetBit(mask->mask, valuator);
@@ -508,13 +508,33 @@ valuator_mask_set(ValuatorMask *mask, int valuator, int data)
 }
 
 /**
- * Return the requested valuator value. If the mask bit is not set for the
- * given valuator, the returned value is undefined.
+ * Set the valuator to the given integer data.
+ */
+void
+valuator_mask_set(ValuatorMask *mask, int valuator, int data)
+{
+    valuator_mask_set_double(mask, valuator, data);
+}
+
+/**
+ * Return the requested valuator value as a double. If the mask bit is not
+ * set for the given valuator, the returned value is undefined.
+ */
+double
+valuator_mask_get_double(const ValuatorMask *mask, int valuator)
+{
+    return mask->valuators[valuator];
+}
+
+/**
+ * Return the requested valuator value as an integer, rounding towards zero.
+ * If the mask bit is not set for the given valuator, the returned value is
+ * undefined.
  */
 int
 valuator_mask_get(const ValuatorMask *mask, int valuator)
 {
-    return mask->valuators[valuator];
+    return trunc(valuator_mask_get_double(mask, valuator));
 }
 
 /**
@@ -527,7 +547,7 @@ valuator_mask_unset(ValuatorMask *mask, int valuator)
         int i, lastbit = -1;
 
         ClearBit(mask->mask, valuator);
-        mask->valuators[valuator] = 0;
+        mask->valuators[valuator] = 0.0;
 
         for (i = 0; i <= mask->last_bit; i++)
             if (valuator_mask_isset(mask, i))
diff --git a/dix/ptrveloc.c b/dix/ptrveloc.c
index dfccf1581..53a0d0397 100644
--- a/dix/ptrveloc.c
+++ b/dix/ptrveloc.c
@@ -63,9 +63,9 @@
 /* fwds */
 int
 SetAccelerationProfile(DeviceVelocityPtr vel, int profile_num);
-static float
-SimpleSmoothProfile(DeviceIntPtr dev, DeviceVelocityPtr vel, float velocity,
-                    float threshold, float acc);
+static double
+SimpleSmoothProfile(DeviceIntPtr dev, DeviceVelocityPtr vel, double velocity,
+                    double threshold, double acc);
 static PointerAccelerationProfileFunc
 GetAccelerationProfile(DeviceVelocityPtr vel, int profile_num);
 static BOOL
@@ -478,14 +478,10 @@ DoGetDirection(int dx, int dy){
         else
             dir = UNDEFINED; /* shouldn't happen */
     } else { /* compute angle and set appropriate flags */
-        float r;
+        double r;
         int i1, i2;
 
-#ifdef _ISOC99_SOURCE
-        r = atan2f(dy, dx);
-#else
         r = atan2(dy, dx);
-#endif
         /* find direction.
          *
          * Add 360° to avoid r become negative since C has no well-defined
@@ -524,8 +520,7 @@ 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) {
+    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) {
@@ -553,7 +548,7 @@ GetDirection(int dx, int dy){
  * 0/0 and set it as the current one.
  */
 static inline void
-FeedTrackers(DeviceVelocityPtr vel, int dx, int dy, int cur_t)
+FeedTrackers(DeviceVelocityPtr vel, double dx, double dy, int cur_t)
 {
     int n;
     for(n = 0; n < vel->num_tracker; n++){
@@ -561,8 +556,8 @@ FeedTrackers(DeviceVelocityPtr vel, int dx, int dy, int cur_t)
 	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].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",
@@ -576,9 +571,9 @@ FeedTrackers(DeviceVelocityPtr vel, int dx, int dy, int cur_t)
  * velocity scaling.
  * This assumes linear motion.
  */
-static float
+static double
 CalcTracker(const MotionTracker *tracker, int cur_t){
-    float dist = sqrt(tracker->dx * tracker->dx + tracker->dy * tracker->dy);
+    double dist = sqrt(tracker->dx * tracker->dx + tracker->dy * tracker->dy);
     int dtime = cur_t - tracker->time;
     if(dtime > 0)
 	return dist / dtime;
@@ -593,16 +588,16 @@ CalcTracker(const MotionTracker *tracker, int cur_t){
  *
  * @return The tracker's velocity or 0 if the above conditions are unmet
  */
-static float
+static double
 QueryTrackers(DeviceVelocityPtr vel, int cur_t){
     int offset, dir = UNDEFINED, used_offset = -1, age_ms;
     /* initial velocity: a low-offset, valid velocity */
-    float initial_velocity = 0, result = 0, velocity_diff;
-    float velocity_factor =  vel->corr_mul * vel->const_acceleration; /* premultiply */
+    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);
-	float tracker_velocity;
+	double tracker_velocity;
 
 	age_ms = cur_t - tracker->time;
 
@@ -674,11 +669,11 @@ QueryTrackers(DeviceVelocityPtr vel, int cur_t){
 BOOL
 ProcessVelocityData2D(
     DeviceVelocityPtr vel,
-    int dx,
-    int dy,
+    double dx,
+    double dy,
     int time)
 {
-    float velocity;
+    double velocity;
 
     vel->last_velocity = vel->velocity;
 
@@ -694,12 +689,12 @@ ProcessVelocityData2D(
  * this flattens significant ( > 1) mickeys a little bit for more steady
  * constant-velocity response
  */
-static inline float
-ApplySimpleSoftening(int prev_delta, int delta)
+static inline double
+ApplySimpleSoftening(double prev_delta, double delta)
 {
-    float result = delta;
+    double result = delta;
 
-    if (delta < -1 || delta > 1) {
+    if (delta < -1.0 || delta > 1.0) {
 	if (delta > prev_delta)
 	    result -= 0.5;
 	else if (delta < prev_delta)
@@ -718,8 +713,8 @@ ApplySimpleSoftening(int prev_delta, int delta)
 static void
 ApplySoftening(
         DeviceVelocityPtr vel,
-        float* fdx,
-        float* fdy)
+        double* fdx,
+        double* fdy)
 {
     if (vel->use_softening) {
         *fdx = ApplySimpleSoftening(vel->last_dx, *fdx);
@@ -728,7 +723,7 @@ ApplySoftening(
 }
 
 static void
-ApplyConstantDeceleration(DeviceVelocityPtr vel, float *fdx, float *fdy)
+ApplyConstantDeceleration(DeviceVelocityPtr vel, double *fdx, double *fdy)
 {
     *fdx *= vel->const_acceleration;
     *fdy *= vel->const_acceleration;
@@ -737,15 +732,15 @@ ApplyConstantDeceleration(DeviceVelocityPtr vel, float *fdx, float *fdy)
 /*
  * compute the acceleration for given velocity and enforce min_acceleartion
  */
-float
+double
 BasicComputeAcceleration(
     DeviceIntPtr dev,
     DeviceVelocityPtr vel,
-    float velocity,
-    float threshold,
-    float acc){
+    double velocity,
+    double threshold,
+    double acc){
 
-    float result;
+    double result;
     result = vel->Profile(dev, vel, velocity, threshold, acc);
 
     /* enforce min_acceleration */
@@ -759,13 +754,13 @@ BasicComputeAcceleration(
  * 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 float
+static double
 ComputeAcceleration(
     DeviceIntPtr dev,
     DeviceVelocityPtr vel,
-    float threshold,
-    float acc){
-    float result;
+    double threshold,
+    double acc){
+    double result;
 
     if(vel->velocity <= 0){
 	DebugAccelF("(dix ptracc) profile skipped\n");
@@ -808,13 +803,13 @@ ComputeAcceleration(
 /**
  * Polynomial function similar previous one, but with f(1) = 1
  */
-static float
+static double
 PolynomialAccelerationProfile(
     DeviceIntPtr dev,
     DeviceVelocityPtr vel,
-    float velocity,
-    float ignored,
-    float acc)
+    double velocity,
+    double ignored,
+    double acc)
 {
    return pow(velocity, (acc - 1.0) * 0.5);
 }
@@ -824,13 +819,13 @@ PolynomialAccelerationProfile(
  * returns acceleration for velocity.
  * This profile selects the two functions like the old scheme did
  */
-static float
+static double
 ClassicProfile(
     DeviceIntPtr dev,
     DeviceVelocityPtr vel,
-    float velocity,
-    float threshold,
-    float acc)
+    double velocity,
+    double threshold,
+    double acc)
 {
     if (threshold > 0) {
 	return SimpleSmoothProfile (dev,
@@ -856,15 +851,15 @@ ClassicProfile(
  * This has the expense of overall response dependency on min-acceleration.
  * In effect, min_acceleration mimics const_acceleration in this profile.
  */
-static float
+static double
 PowerProfile(
     DeviceIntPtr dev,
     DeviceVelocityPtr vel,
-    float velocity,
-    float threshold,
-    float acc)
+    double velocity,
+    double threshold,
+    double acc)
 {
-    float vel_dist;
+    double vel_dist;
 
     acc = (acc-1.0) * 0.1f + 1.0; /* without this, acc of 2 is unuseable */
 
@@ -882,11 +877,11 @@ PowerProfile(
  *  - starts faster than a sinoid
  *  - smoothness C1 (Cinf if you dare to ignore endpoints)
  */
-static inline float
-CalcPenumbralGradient(float x){
+static inline double
+CalcPenumbralGradient(double x){
     x *= 2.0f;
     x -= 1.0f;
-    return 0.5f + (x * sqrt(1.0f - x*x) + asin(x))/M_PI;
+    return 0.5f + (x * sqrt(1.0 - x*x) + asin(x))/M_PI;
 }
 
 
@@ -894,13 +889,13 @@ CalcPenumbralGradient(float x){
  * acceleration function similar to classic accelerated/unaccelerated,
  * but with smooth transition in between (and towards zero for adaptive dec.).
  */
-static float
+static double
 SimpleSmoothProfile(
     DeviceIntPtr dev,
     DeviceVelocityPtr vel,
-    float velocity,
-    float threshold,
-    float acc)
+    double velocity,
+    double threshold,
+    double acc)
 {
     if(velocity < 1.0f)
         return CalcPenumbralGradient(0.5 + velocity*0.5) * 2.0f - 1.0f;
@@ -920,15 +915,15 @@ SimpleSmoothProfile(
  * This profile uses the first half of the penumbral gradient as a start
  * and then scales linearly.
  */
-static float
+static double
 SmoothLinearProfile(
     DeviceIntPtr dev,
     DeviceVelocityPtr vel,
-    float velocity,
-    float threshold,
-    float acc)
+    double velocity,
+    double threshold,
+    double acc)
 {
-    float res, nv;
+    double res, nv;
 
     if(acc > 1.0f)
         acc -= 1.0f; /*this is so acc = 1 is no acceleration */
@@ -955,15 +950,15 @@ SmoothLinearProfile(
  * From 0 to threshold, the response graduates smoothly from min_accel to
  * acceleration. Beyond threshold it is exactly the specified acceleration.
  */
-static float
+static double
 SmoothLimitedProfile(
     DeviceIntPtr dev,
     DeviceVelocityPtr vel,
-    float velocity,
-    float threshold,
-    float acc)
+    double velocity,
+    double threshold,
+    double acc)
 {
-    float res;
+    double res;
 
     if(velocity >= threshold || threshold == 0.0f)
 	return acc;
@@ -976,24 +971,24 @@ SmoothLimitedProfile(
 }
 
 
-static float
+static double
 LinearProfile(
     DeviceIntPtr dev,
     DeviceVelocityPtr vel,
-    float velocity,
-    float threshold,
-    float acc)
+    double velocity,
+    double threshold,
+    double acc)
 {
     return acc * velocity;
 }
 
-static float
+static double
 NoProfile(
     DeviceIntPtr dev,
     DeviceVelocityPtr vel,
-    float velocity,
-    float threshold,
-    float acc)
+    double velocity,
+    double threshold,
+    double acc)
 {
     return 1.0f;
 }
@@ -1119,11 +1114,11 @@ acceleratePointerPredictable(
     ValuatorMask* val,
     CARD32 evtime)
 {
-    int dx = 0, dy = 0, tmpi;
+    double dx = 0, dy = 0;
     DeviceVelocityPtr velocitydata = GetDevicePredictableAccelData(dev);
     Bool soften = TRUE;
 
-    if (!velocitydata)
+    if (valuator_mask_num_valuators(val) == 0 || !velocitydata)
         return;
 
     if (velocitydata->statistics.profile_number == AccelProfileNone &&
@@ -1132,59 +1127,39 @@ acceleratePointerPredictable(
     }
 
     if (valuator_mask_isset(val, 0)) {
-        dx = valuator_mask_get(val, 0);
+        dx = valuator_mask_get_double(val, 0);
     }
 
     if (valuator_mask_isset(val, 1)) {
-        dy = valuator_mask_get(val, 1);
+        dy = valuator_mask_get_double(val, 1);
     }
 
-    if (dx || dy){
+    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) {
-            float mult;
+            double mult;
 
             /* invoke acceleration profile to determine acceleration */
             mult = ComputeAcceleration (dev, velocitydata,
-                                        dev->ptrfeed->ctrl.threshold,
-                                        (float)dev->ptrfeed->ctrl.num /
-                                            (float)dev->ptrfeed->ctrl.den);
+					dev->ptrfeed->ctrl.threshold,
+					(double)dev->ptrfeed->ctrl.num /
+					(double)dev->ptrfeed->ctrl.den);
 
             if(mult != 1.0f || velocitydata->const_acceleration != 1.0f) {
-                float fdx = dx,
-                      fdy = dy;
-
                 if (mult > 1.0f && soften)
-                    ApplySoftening(velocitydata, &fdx, &fdy);
-                ApplyConstantDeceleration(velocitydata, &fdx, &fdy);
-
-                /* Calculate the new delta (with accel) and drop it back
-                 * into the valuator masks */
-                if (dx) {
-                    float tmp;
-                    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. */
-                    tmpi = lrintf(tmp);
-                    valuator_mask_set(val, 0, tmpi);
-                    dev->last.remainder[0] = tmp - (float)tmpi;
-                }
-                if (dy) {
-                    float tmp;
-                    tmp = mult * fdy + dev->last.remainder[1];
-                    tmpi = lrintf(tmp);
-                    valuator_mask_set(val, 1, tmpi);
-                    dev->last.remainder[1] = tmp - (float)tmpi;
-                }
-                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);
+                    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);
             }
         }
     }
@@ -1205,8 +1180,8 @@ acceleratePointerLightweight(
     ValuatorMask* val,
     CARD32 ignored)
 {
-    float mult = 0.0, tmpf;
-    int dx = 0, dy = 0, tmpi;
+    double mult = 0.0, tmpf;
+    double dx = 0.0, dy = 0.0;
 
     if (valuator_mask_isset(val, 0)) {
         dx = valuator_mask_get(val, 0);
@@ -1216,53 +1191,35 @@ acceleratePointerLightweight(
         dy = valuator_mask_get(val, 1);
     }
 
-    if (!dx && !dy)
+    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 ((abs(dx) + abs(dy)) >= dev->ptrfeed->ctrl.threshold) {
-                tmpf = ((float)dx *
-                        (float)(dev->ptrfeed->ctrl.num)) /
-                       (float)(dev->ptrfeed->ctrl.den) +
-                       dev->last.remainder[0];
-                if (dx) {
-                    tmpi = (int) tmpf;
-                    valuator_mask_set(val, 0, tmpi);
-                    dev->last.remainder[0] = tmpf - (float)tmpi;
+            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);
                 }
 
-                tmpf = ((float)dy *
-                        (float)(dev->ptrfeed->ctrl.num)) /
-                       (float)(dev->ptrfeed->ctrl.den) +
-                       dev->last.remainder[1];
-                if (dy) {
-                    tmpi = (int) tmpf;
-                    valuator_mask_set(val, 1, tmpi);
-                    dev->last.remainder[1] = tmpf - (float)tmpi;
+                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((float)dx * (float)dx + (float)dy * (float)dy,
-                       ((float)(dev->ptrfeed->ctrl.num) /
-                        (float)(dev->ptrfeed->ctrl.den) - 1.0) /
+	    mult = pow(dx * dx + dy * dy,
+                       ((double)(dev->ptrfeed->ctrl.num) /
+                        (double)(dev->ptrfeed->ctrl.den) - 1.0) /
                        2.0) / 2.0;
-            if (dx) {
-                tmpf = mult * (float)dx +
-                       dev->last.remainder[0];
-                tmpi = (int) tmpf;
-                valuator_mask_set(val, 0, tmpi);
-                dev->last.remainder[0] = tmpf - (float)tmpi;
-            }
-            if (dy) {
-                tmpf = mult * (float)dy +
-                       dev->last.remainder[1];
-                tmpi = (int)tmpf;
-                valuator_mask_set(val, 1, tmpi);
-                dev->last.remainder[1] = tmpf - (float)tmpi;
-            }
+            if (dx != 0.0)
+                valuator_mask_set_double(val, 0, mult * dx);
+            if (dy != 0.0)
+                valuator_mask_set_double(val, 1, mult * dy);
         }
     }
 }