xenocara/xserver/dix/getevents.c

/*
 * 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"),
 * 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.
 *
 * Authors: Daniel Stone <daniel@fooishbar.org>
 *          Peter Hutterer <peter.hutterer@who-t.net>
 */

#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#include <X11/X.h>
#include <X11/keysym.h>
#include <X11/Xproto.h>
#include <math.h>
#include <limits.h>

#include "misc.h"
#include "resource.h"
#include "inputstr.h"
#include "scrnintstr.h"
#include "cursorstr.h"
#include "dixstruct.h"
#include "globals.h"
#include "dixevents.h"
#include "mipointer.h"
#include "eventstr.h"
#include "eventconvert.h"
#include "inpututils.h"
#include "mi.h"
#include "windowstr.h"

#include <X11/extensions/XKBproto.h>
#include "xkbsrv.h"

#ifdef PANORAMIX
#include "panoramiX.h"
#include "panoramiXsrv.h"
#endif

#include <X11/extensions/XI.h>
#include <X11/extensions/XI2.h>
#include <X11/extensions/XIproto.h>
#include <pixman.h>
#include "exglobals.h"
#include "exevents.h"
#include "extnsionst.h"
#include "listdev.h"            /* for sizing up DeviceClassesChangedEvent */

/* Number of motion history events to store. */
#define MOTION_HISTORY_SIZE 256

/**
 * InputEventList is the storage for input events generated by
 * QueuePointerEvents, QueueKeyboardEvents, and QueueProximityEvents.
 * This list is allocated on startup by the DIX.
 */
InternalEvent *InputEventList = NULL;

/**
 * Pick some arbitrary size for Xi motion history.
 */
int
GetMotionHistorySize(void)
{
    return MOTION_HISTORY_SIZE;
}

void
set_button_down(DeviceIntPtr pDev, int button, int type)
{
    if (type == BUTTON_PROCESSED)
        SetBit(pDev->button->down, button);
    else
        SetBit(pDev->button->postdown, button);
}

void
set_button_up(DeviceIntPtr pDev, int button, int type)
{
    if (type == BUTTON_PROCESSED)
        ClearBit(pDev->button->down, button);
    else
        ClearBit(pDev->button->postdown, button);
}

Bool
button_is_down(DeviceIntPtr pDev, int button, int type)
{
    Bool ret = FALSE;

    if (type & BUTTON_PROCESSED)
        ret = ret || BitIsOn(pDev->button->down, button);
    if (type & BUTTON_POSTED)
        ret = ret || BitIsOn(pDev->button->postdown, button);

    return ret;
}

void
set_key_down(DeviceIntPtr pDev, int key_code, int type)
{
    if (type == KEY_PROCESSED)
        SetBit(pDev->key->down, key_code);
    else
        SetBit(pDev->key->postdown, key_code);
}

void
set_key_up(DeviceIntPtr pDev, int key_code, int type)
{
    if (type == KEY_PROCESSED)
        ClearBit(pDev->key->down, key_code);
    else
        ClearBit(pDev->key->postdown, key_code);
}

Bool
key_is_down(DeviceIntPtr pDev, int key_code, int type)
{
    Bool ret = FALSE;

    if (type & KEY_PROCESSED)
        ret = ret || BitIsOn(pDev->key->down, key_code);
    if (type & KEY_POSTED)
        ret = ret || BitIsOn(pDev->key->postdown, key_code);

    return ret;
}

static Bool
key_autorepeats(DeviceIntPtr pDev, int key_code)
{
    return ! !(pDev->kbdfeed->ctrl.autoRepeats[key_code >> 3] &
               (1 << (key_code & 7)));
}

static void
init_event(DeviceIntPtr dev, DeviceEvent *event, Time ms)
{
    memset(event, 0, sizeof(DeviceEvent));
    event->header = ET_Internal;
    event->length = sizeof(DeviceEvent);
    event->time = ms;
    event->deviceid = dev->id;
    event->sourceid = dev->id;
}

static void
init_touch_ownership(DeviceIntPtr dev, TouchOwnershipEvent *event, Time ms)
{
    memset(event, 0, sizeof(TouchOwnershipEvent));
    event->header = ET_Internal;
    event->type = ET_TouchOwnership;
    event->length = sizeof(TouchOwnershipEvent);
    event->time = ms;
    event->deviceid = dev->id;
}

static void
init_raw(DeviceIntPtr dev, RawDeviceEvent *event, Time ms, int type, int detail)
{
    memset(event, 0, sizeof(RawDeviceEvent));
    event->header = ET_Internal;
    event->length = sizeof(RawDeviceEvent);
    switch (type) {
    case MotionNotify:
        event->type = ET_RawMotion;
        break;
    case ButtonPress:
        event->type = ET_RawButtonPress;
        break;
    case ButtonRelease:
        event->type = ET_RawButtonRelease;
        break;
    case KeyPress:
        event->type = ET_RawKeyPress;
        break;
    case KeyRelease:
        event->type = ET_RawKeyRelease;
        break;
    case XI_TouchBegin:
        event->type = ET_RawTouchBegin;
        break;
    case XI_TouchUpdate:
        event->type = ET_RawTouchUpdate;
        break;
    case XI_TouchEnd:
        event->type = ET_RawTouchEnd;
        break;
    }
    event->time = ms;
    event->deviceid = dev->id;
    event->sourceid = dev->id;
    event->detail.button = detail;
}

static void
set_raw_valuators(RawDeviceEvent *event, ValuatorMask *mask, double *data)
{
    int i;

    for (i = 0; i < valuator_mask_size(mask); i++) {
        if (valuator_mask_isset(mask, i)) {
            SetBit(event->valuators.mask, i);
            data[i] = valuator_mask_get_double(mask, i);
        }
    }
}

static void
set_valuators(DeviceIntPtr dev, DeviceEvent *event, ValuatorMask *mask)
{
    int i;

    /* Set the data to the previous value for unset absolute axes. The values
     * may be used when sent as part of an XI 1.x valuator event. */
    for (i = 0; i < valuator_mask_size(mask); i++) {
        if (valuator_mask_isset(mask, i)) {
            SetBit(event->valuators.mask, i);
            if (valuator_get_mode(dev, i) == Absolute)
                SetBit(event->valuators.mode, i);
            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];
    }
}

void
CreateClassesChangedEvent(InternalEvent *event,
                          DeviceIntPtr master, DeviceIntPtr slave, int flags)
{
    int i;
    DeviceChangedEvent *dce;
    CARD32 ms = GetTimeInMillis();

    dce = &event->changed_event;
    memset(dce, 0, sizeof(DeviceChangedEvent));
    dce->deviceid = slave->id;
    dce->masterid = master ? master->id : 0;
    dce->header = ET_Internal;
    dce->length = sizeof(DeviceChangedEvent);
    dce->type = ET_DeviceChanged;
    dce->time = ms;
    dce->flags = flags;
    dce->sourceid = slave->id;

    if (slave->button) {
        dce->buttons.num_buttons = slave->button->numButtons;
        for (i = 0; i < dce->buttons.num_buttons; i++)
            dce->buttons.names[i] = slave->button->labels[i];
    }
    if (slave->valuator) {
        dce->num_valuators = slave->valuator->numAxes;
        for (i = 0; i < dce->num_valuators; i++) {
            dce->valuators[i].min = slave->valuator->axes[i].min_value;
            dce->valuators[i].max = slave->valuator->axes[i].max_value;
            dce->valuators[i].resolution = slave->valuator->axes[i].resolution;
            dce->valuators[i].mode = slave->valuator->axes[i].mode;
            dce->valuators[i].name = slave->valuator->axes[i].label;
            dce->valuators[i].scroll = slave->valuator->axes[i].scroll;
        }
    }
    if (slave->key) {
        dce->keys.min_keycode = slave->key->xkbInfo->desc->min_key_code;
        dce->keys.max_keycode = slave->key->xkbInfo->desc->max_key_code;
    }
}

/**
 * Rescale the coord between the two axis ranges.
 */
static double
rescaleValuatorAxis(double coord, AxisInfoPtr from, AxisInfoPtr to,
                    double defmin, double defmax)
{
    double fmin = defmin, fmax = defmax;
    double tmin = defmin, tmax = defmax;

    if (from && from->min_value < from->max_value) {
        fmin = from->min_value;
        fmax = from->max_value;
    }
    if (to && to->min_value < to->max_value) {
        tmin = to->min_value;
        tmax = to->max_value;
    }

    if (fmin == tmin && fmax == tmax)
        return coord;

    if (fmax == fmin)           /* avoid division by 0 */
        return 0.0;

    return (coord - fmin) * (tmax - tmin) / (fmax - fmin) + tmin;
}

/**
 * Update all coordinates when changing to a different SD
 * to ensure that relative reporting will work as expected
 * without loss of precision.
 *
 * pDev->last.valuators will be in absolute device coordinates after this
 * function.
 */
static void
updateSlaveDeviceCoords(DeviceIntPtr master, DeviceIntPtr pDev)
{
    int i;
    DeviceIntPtr lastSlave;

    /* master->last.valuators[0]/[1] is in desktop-wide coords and the actual
     * position of the pointer */
    pDev->last.valuators[0] = master->last.valuators[0];
    pDev->last.valuators[1] = master->last.valuators[1];

    if (!pDev->valuator)
        return;

    /* scale back to device coordinates */
    if (pDev->valuator->numAxes > 0) {
        pDev->last.valuators[0] = rescaleValuatorAxis(pDev->last.valuators[0],
                                                      NULL,
                                                      pDev->valuator->axes + 0,
                                                      screenInfo.x,
                                                      screenInfo.width);
    }
    if (pDev->valuator->numAxes > 1) {
        pDev->last.valuators[1] = rescaleValuatorAxis(pDev->last.valuators[1],
                                                      NULL,
                                                      pDev->valuator->axes + 1,
                                                      screenInfo.y,
                                                      screenInfo.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,
     * last.valuators is reset to 0.
     */
    if ((lastSlave = master->last.slave) && lastSlave->valuator) {
        for (i = 2; i < pDev->valuator->numAxes; i++) {
            if (i >= lastSlave->valuator->numAxes) {
                pDev->last.valuators[i] = 0;
                valuator_mask_set_double(pDev->last.scroll, i, 0);
            }
            else {
                double val = pDev->last.valuators[i];

                val = rescaleValuatorAxis(val, lastSlave->valuator->axes + i,
                                          pDev->valuator->axes + i, 0, 0);
                pDev->last.valuators[i] = val;
                valuator_mask_set_double(pDev->last.scroll, i, val);
            }
        }
    }

}

/**
 * Allocate the motion history buffer.
 */
void
AllocateMotionHistory(DeviceIntPtr pDev)
{
    int size;

    free(pDev->valuator->motion);

    if (pDev->valuator->numMotionEvents < 1)
        return;

    /* An MD must have a motion history size large enough to keep all
     * potential valuators, plus the respective range of the valuators.
     * 3 * INT32 for (min_val, max_val, curr_val))
     */
    if (IsMaster(pDev))
        size = sizeof(INT32) * 3 * MAX_VALUATORS;
    else {
        ValuatorClassPtr v = pDev->valuator;
        int numAxes;

        /* XI1 doesn't understand mixed mode devices */
        for (numAxes = 0; numAxes < v->numAxes; numAxes++)
            if (valuator_get_mode(pDev, numAxes) != valuator_get_mode(pDev, 0))
                break;
        size = sizeof(INT32) * numAxes;
    }

    size += sizeof(Time);

    pDev->valuator->motion = calloc(pDev->valuator->numMotionEvents, size);
    pDev->valuator->first_motion = 0;
    pDev->valuator->last_motion = 0;
    if (!pDev->valuator->motion)
        ErrorF("[dix] %s: Failed to alloc motion history (%d bytes).\n",
               pDev->name, size * pDev->valuator->numMotionEvents);
}

/**
 * Dump the motion history between start and stop into the supplied buffer.
 * Only records the event for a given screen in theory, but in practice, we
 * sort of ignore this.
 *
 * If core is set, we only generate x/y, in INT16, scaled to screen coords.
 */
int
GetMotionHistory(DeviceIntPtr pDev, xTimecoord ** buff, unsigned long start,
                 unsigned long stop, ScreenPtr pScreen, BOOL core)
{
    char *ibuff = NULL, *obuff;
    int i = 0, ret = 0;
    int j, coord;
    Time current;

    /* The size of a single motion event. */
    int size;
    AxisInfo from, *to;         /* for scaling */
    INT32 *ocbuf, *icbuf;       /* pointer to coordinates for copying */
    INT16 *corebuf;
    AxisInfo core_axis = { 0 };

    if (!pDev->valuator || !pDev->valuator->numMotionEvents)
        return 0;

    if (core && !pScreen)
        return 0;

    if (IsMaster(pDev))
        size = (sizeof(INT32) * 3 * MAX_VALUATORS) + sizeof(Time);
    else
        size = (sizeof(INT32) * pDev->valuator->numAxes) + sizeof(Time);

    *buff = malloc(size * pDev->valuator->numMotionEvents);
    if (!(*buff))
        return 0;
    obuff = (char *) *buff;

    for (i = pDev->valuator->first_motion;
         i != pDev->valuator->last_motion;
         i = (i + 1) % pDev->valuator->numMotionEvents) {
        /* We index the input buffer by which element we're accessing, which
         * is not monotonic, and the output buffer by how many events we've
         * written so far. */
        ibuff = (char *) pDev->valuator->motion + (i * size);
        memcpy(&current, ibuff, sizeof(Time));

        if (current > stop) {
            return ret;
        }
        else if (current >= start) {
            if (core) {
                memcpy(obuff, ibuff, sizeof(Time));     /* copy timestamp */

                icbuf = (INT32 *) (ibuff + sizeof(Time));
                corebuf = (INT16 *) (obuff + sizeof(Time));

                /* fetch x coordinate + range */
                memcpy(&from.min_value, icbuf++, sizeof(INT32));
                memcpy(&from.max_value, icbuf++, sizeof(INT32));
                memcpy(&coord, icbuf++, sizeof(INT32));

                /* scale to screen coords */
                to = &core_axis;
                to->max_value = pScreen->width;
                coord =
                    rescaleValuatorAxis(coord, &from, to, 0, pScreen->width);

                memcpy(corebuf, &coord, sizeof(INT16));
                corebuf++;

                /* fetch y coordinate + range */
                memcpy(&from.min_value, icbuf++, sizeof(INT32));
                memcpy(&from.max_value, icbuf++, sizeof(INT32));
                memcpy(&coord, icbuf++, sizeof(INT32));

                to->max_value = pScreen->height;
                coord =
                    rescaleValuatorAxis(coord, &from, to, 0, pScreen->height);
                memcpy(corebuf, &coord, sizeof(INT16));

            }
            else if (IsMaster(pDev)) {
                memcpy(obuff, ibuff, sizeof(Time));     /* copy timestamp */

                ocbuf = (INT32 *) (obuff + sizeof(Time));
                icbuf = (INT32 *) (ibuff + sizeof(Time));
                for (j = 0; j < MAX_VALUATORS; j++) {
                    if (j >= pDev->valuator->numAxes)
                        break;

                    /* fetch min/max/coordinate */
                    memcpy(&from.min_value, icbuf++, sizeof(INT32));
                    memcpy(&from.max_value, icbuf++, sizeof(INT32));
                    memcpy(&coord, icbuf++, sizeof(INT32));

                    to = (j <
                          pDev->valuator->numAxes) ? &pDev->valuator->
                        axes[j] : NULL;

                    /* x/y scaled to screen if no range is present */
                    if (j == 0 && (from.max_value < from.min_value))
                        from.max_value = pScreen->width;
                    else if (j == 1 && (from.max_value < from.min_value))
                        from.max_value = pScreen->height;

                    /* scale from stored range into current range */
                    coord = rescaleValuatorAxis(coord, &from, to, 0, 0);
                    memcpy(ocbuf, &coord, sizeof(INT32));
                    ocbuf++;
                }
            }
            else
                memcpy(obuff, ibuff, size);

            /* don't advance by size here. size may be different to the
             * actually written size if the MD has less valuators than MAX */
            if (core)
                obuff += sizeof(INT32) + sizeof(Time);
            else
                obuff +=
                    (sizeof(INT32) * pDev->valuator->numAxes) + sizeof(Time);
            ret++;
        }
    }

    return ret;
}

/**
 * Update the motion history for a specific device, with the list of
 * valuators.
 *
 * Layout of the history buffer:
 *   for SDs: [time] [val0] [val1] ... [valn]
 *   for MDs: [time] [min_val0] [max_val0] [val0] [min_val1] ... [valn]
 *
 * For events that have some valuators unset:
 *      min_val == max_val == val == 0.
 */
static void
updateMotionHistory(DeviceIntPtr pDev, CARD32 ms, ValuatorMask *mask,
                    double *valuators)
{
    char *buff = (char *) pDev->valuator->motion;
    ValuatorClassPtr v;
    int i;

    if (!pDev->valuator->numMotionEvents)
        return;

    v = pDev->valuator;
    if (IsMaster(pDev)) {
        buff += ((sizeof(INT32) * 3 * MAX_VALUATORS) + sizeof(CARD32)) *
            v->last_motion;

        memcpy(buff, &ms, sizeof(Time));
        buff += sizeof(Time);

        memset(buff, 0, sizeof(INT32) * 3 * MAX_VALUATORS);

        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;
            if (valuator_mask_size(mask) <= i || !valuator_mask_isset(mask, i)) {
                buff += 3 * sizeof(INT32);
                continue;
            }
            memcpy(buff, &v->axes[i].min_value, sizeof(INT32));
            buff += sizeof(INT32);
            memcpy(buff, &v->axes[i].max_value, sizeof(INT32));
            buff += sizeof(INT32);
            val = valuators[i];
            memcpy(buff, &val, sizeof(INT32));
            buff += sizeof(INT32);
        }
    }
    else {

        buff += ((sizeof(INT32) * pDev->valuator->numAxes) + sizeof(CARD32)) *
            pDev->valuator->last_motion;

        memcpy(buff, &ms, sizeof(Time));
        buff += sizeof(Time);

        memset(buff, 0, sizeof(INT32) * pDev->valuator->numAxes);

        for (i = 0; i < MAX_VALUATORS; i++) {
            int val;

            if (valuator_mask_size(mask) <= i || !valuator_mask_isset(mask, i)) {
                buff += sizeof(INT32);
                continue;
            }
            val = valuators[i];
            memcpy(buff, &val, sizeof(INT32));
            buff += sizeof(INT32);
        }
    }

    pDev->valuator->last_motion = (pDev->valuator->last_motion + 1) %
        pDev->valuator->numMotionEvents;
    /* If we're wrapping around, just keep the circular buffer going. */
    if (pDev->valuator->first_motion == pDev->valuator->last_motion)
        pDev->valuator->first_motion = (pDev->valuator->first_motion + 1) %
            pDev->valuator->numMotionEvents;

    return;
}

/**
 * Returns the maximum number of events GetKeyboardEvents
 * and GetPointerEvents will ever return.
 *
 * This MUST be absolutely constant, from init until exit.
 */
int
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 100;
}

/**
 * Clip an axis to its bounds, which are declared in the call to
 * InitValuatorAxisClassStruct.
 */
static void
clipAxis(DeviceIntPtr pDev, int axisNum, double *val)
{
    AxisInfoPtr axis;

    if (axisNum >= pDev->valuator->numAxes)
        return;

    axis = pDev->valuator->axes + axisNum;

    /* If a value range is defined, clip. If not, do nothing */
    if (axis->max_value <= axis->min_value)
        return;

    if (*val < axis->min_value)
        *val = axis->min_value;
    if (*val > axis->max_value)
        *val = axis->max_value;
}

/**
 * Clip every axis in the list of valuators to its bounds.
 */
static void
clipValuators(DeviceIntPtr pDev, ValuatorMask *mask)
{
    int i;

    for (i = 0; i < valuator_mask_size(mask); i++)
        if (valuator_mask_isset(mask, i)) {
            double val = valuator_mask_get_double(mask, i);

            clipAxis(pDev, i, &val);
            valuator_mask_set_double(mask, i, val);
        }
}

/**
 * Create the DCCE event (does not update the master's device state yet, this
 * is done in the event processing).
 * Pull in the coordinates from the MD if necessary.
 *
 * @param events Pointer to a pre-allocated event array.
 * @param dev The slave device that generated an event.
 * @param type Either DEVCHANGE_POINTER_EVENT and/or DEVCHANGE_KEYBOARD_EVENT
 * @param num_events The current number of events, returns the number of
 *        events if a DCCE was generated.
 * @return The updated @events pointer.
 */
InternalEvent *
UpdateFromMaster(InternalEvent *events, DeviceIntPtr dev, int type,
                 int *num_events)
{
    DeviceIntPtr master;

    master =
        GetMaster(dev,
                  (type & DEVCHANGE_POINTER_EVENT) ? MASTER_POINTER :
                  MASTER_KEYBOARD);

    if (master && master->last.slave != dev) {
        CreateClassesChangedEvent(events, master, dev,
                                  type | DEVCHANGE_SLAVE_SWITCH);
        if (IsPointerDevice(master)) {
            updateSlaveDeviceCoords(master, dev);
            master->last.numValuators = dev->last.numValuators;
        }
        master->last.slave = dev;
        (*num_events)++;
        events++;
    }
    return events;
}

/**
 * Move the device's pointer to the position given in the valuators.
 *
 * @param dev The device whose pointer is to be moved.
 * @param mask Valuator data for this event.
 */
static void
clipAbsolute(DeviceIntPtr dev, ValuatorMask *mask)
{
    int i;

    for (i = 0; i < valuator_mask_size(mask); 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);
    }
}

static void
add_to_scroll_valuator(DeviceIntPtr dev, ValuatorMask *mask, int valuator, double value)
{
    double v;

    if (!valuator_mask_fetch_double(mask, valuator, &v))
        return;

    /* protect against scrolling overflow. INT_MAX for double, because
     * we'll eventually write this as 32.32 fixed point */
    if ((value > 0 && v > INT_MAX - value) || (value < 0 && v < INT_MIN - value)) {
        v = 0;

        /* reset last.scroll to avoid a button storm */
        valuator_mask_set_double(dev->last.scroll, valuator, 0);
    }
    else
        v += value;

    valuator_mask_set_double(mask, valuator, v);
}


/**
 * Move the device's pointer by the values given in @valuators.
 *
 * @param dev The device whose pointer is to be moved.
 * @param[in,out] mask Valuator data for this event, modified in-place.
 */
static void
moveRelative(DeviceIntPtr dev, ValuatorMask *mask)
{
    int i;
    Bool clip_xy = IsMaster(dev) || !IsFloating(dev);

    /* calc other axes, clip, drop back into valuators */
    for (i = 0; i < valuator_mask_size(mask); i++) {
        double val = dev->last.valuators[i];

        if (!valuator_mask_isset(mask, i))
            continue;

        add_to_scroll_valuator(dev, mask, i, val);

        /* 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)) {
            val = valuator_mask_get_double(mask, i);
            clipAxis(dev, i, &val);
            valuator_mask_set_double(mask, i, val);
        }
    }
}

/**
 * Accelerate the data in valuators based on the device's acceleration scheme.
 *
 * @param dev The device which's pointer is to be moved.
 * @param valuators Valuator mask
 * @param ms Current time.
 */
static void
accelPointer(DeviceIntPtr dev, ValuatorMask *valuators, CARD32 ms)
{
    if (dev->valuator->accelScheme.AccelSchemeProc)
        dev->valuator->accelScheme.AccelSchemeProc(dev, valuators, ms);
}

/**
 * Scale from absolute screen coordinates to absolute coordinates in the
 * device's coordinate range.
 *
 * @param dev The device to scale for.
 * @param[in, out] mask The mask in desktop coordinates, modified in place
 * to contain device coordinate range.
 */
static void
scale_from_screen(DeviceIntPtr dev, ValuatorMask *mask)
{
    double scaled;
    ScreenPtr scr = miPointerGetScreen(dev);

    if (valuator_mask_isset(mask, 0)) {
        scaled = valuator_mask_get_double(mask, 0) + scr->x;
        scaled = rescaleValuatorAxis(scaled,
                                     NULL, dev->valuator->axes + 0,
                                     0, scr->width);
        valuator_mask_set_double(mask, 0, scaled);
    }
    if (valuator_mask_isset(mask, 1)) {
        scaled = valuator_mask_get_double(mask, 1) + scr->y;
        scaled = rescaleValuatorAxis(scaled,
                                     NULL, dev->valuator->axes + 1,
                                     0, scr->height);
        valuator_mask_set_double(mask, 1, scaled);
    }
}

/**
 * Scale from (absolute) device to screen coordinates here,
 *
 * The coordinates provided are always absolute. see fill_pointer_events for
 * information on coordinate systems.
 *
 * @param dev The device to be moved.
 * @param mask Mask of axis values for this event
 * @param[out] devx x desktop-wide coordinate in device coordinate system
 * @param[out] devy y desktop-wide coordinate in device coordinate system
 * @param[out] screenx x coordinate in desktop coordinate system
 * @param[out] screeny y coordinate in desktop coordinate system
 */
static ScreenPtr
scale_to_desktop(DeviceIntPtr dev, ValuatorMask *mask,
                 double *devx, double *devy, double *screenx, double *screeny)
{
    ScreenPtr scr = miPointerGetScreen(dev);
    double x, y;

    BUG_WARN(dev->valuator && dev->valuator->numAxes < 2);
    if (!dev->valuator || dev->valuator->numAxes < 2) {
        /* if we have no axes, last.valuators must be in screen coords
         * anyway */
        *devx = *screenx = dev->last.valuators[0];
        *devy = *screeny = dev->last.valuators[1];
        return scr;
    }

    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];

    /* scale x&y to desktop coordinates */
    *screenx = rescaleValuatorAxis(x, dev->valuator->axes + 0, NULL,
                                   screenInfo.x, screenInfo.width);
    *screeny = rescaleValuatorAxis(y, dev->valuator->axes + 1, NULL,
                                   screenInfo.y, screenInfo.height);

    *devx = x;
    *devy = y;

    return scr;
}

/**
 * If we have HW cursors, this actually moves the visible sprite. If not, we
 * just do all the screen crossing, etc.
 *
 * We use the screen coordinates here, call miPointerSetPosition() and then
 * scale back into device coordinates (if needed). miPSP will change x/y if
 * the screen was crossed.
 *
 * The coordinates provided are always absolute. The parameter mode
 * specifies whether it was relative or absolute movement that landed us at
 * those coordinates. see fill_pointer_events for information on coordinate
 * systems.
 *
 * @param dev The device to be moved.
 * @param mode Movement mode (Absolute or Relative)
 * @param[out] mask Mask of axis values for this event, returns the
 * per-screen device coordinates after confinement
 * @param[in,out] devx x desktop-wide coordinate in device coordinate system
 * @param[in,out] devy y desktop-wide coordinate in device coordinate system
 * @param[in,out] screenx x coordinate in desktop coordinate system
 * @param[in,out] screeny y coordinate in desktop coordinate system
 */
static ScreenPtr
positionSprite(DeviceIntPtr dev, int mode, ValuatorMask *mask,
               double *devx, double *devy, double *screenx, double *screeny)
{
    ScreenPtr scr = miPointerGetScreen(dev);
    double tmpx, tmpy;

    if (!dev->valuator || dev->valuator->numAxes < 2)
        return scr;

    tmpx = *screenx;
    tmpy = *screeny;

    /* miPointerSetPosition takes care of crossing screens for us, as well as
     * clipping to the current screen. Coordinates returned are in desktop
     * coord system */
    scr = miPointerSetPosition(dev, mode, screenx, screeny);

    /* If we were constrained, rescale x/y from the screen coordinates so
     * the device valuators reflect the correct position. For screen
     * crossing this doesn't matter much, the coords would be 0 or max.
     */
    if (tmpx != *screenx)
        *devx = rescaleValuatorAxis(*screenx, NULL, dev->valuator->axes + 0,
                                    screenInfo.x, screenInfo.width);

    if (tmpy != *screeny)
        *devy = rescaleValuatorAxis(*screeny, NULL, dev->valuator->axes + 1,
                                    screenInfo.y, screenInfo.height);

    /* Recalculate the per-screen device coordinates */
    if (valuator_mask_isset(mask, 0)) {
        double x;

        x = rescaleValuatorAxis(*screenx - scr->x, NULL,
                                dev->valuator->axes + 0, 0, scr->width);
        valuator_mask_set_double(mask, 0, x);
    }
    if (valuator_mask_isset(mask, 1)) {
        double y;

        y = rescaleValuatorAxis(*screeny - scr->y, NULL,
                                dev->valuator->axes + 1, 0, scr->height);
        valuator_mask_set_double(mask, 1, y);
    }

    return scr;
}

/**
 * Update the motion history for the device and (if appropriate) for its
 * master device.
 * @param dev Slave device to update.
 * @param mask Bit mask of valid valuators to append to history.
 * @param num Total number of valuators to append to history.
 * @param ms Current time
 */
static void
updateHistory(DeviceIntPtr dev, ValuatorMask *mask, CARD32 ms)
{
    if (!dev->valuator)
        return;

    updateMotionHistory(dev, ms, mask, dev->last.valuators);
    if (!IsMaster(dev) && !IsFloating(dev)) {
        DeviceIntPtr master = GetMaster(dev, MASTER_POINTER);

        updateMotionHistory(master, ms, mask, dev->last.valuators);
    }
}

static void
queueEventList(DeviceIntPtr device, InternalEvent *events, int nevents)
{
    int i;

    for (i = 0; i < nevents; i++)
        mieqEnqueue(device, &events[i]);
}

static void
event_set_root_coordinates(DeviceEvent *event, double x, double y)
{
    event->root_x = trunc(x);
    event->root_y = trunc(y);
    event->root_x_frac = x - trunc(x);
    event->root_y_frac = y - trunc(y);
}

/**
 * Generate internal events representing this keyboard event and enqueue
 * them on the event queue.
 *
 * This function is not reentrant. Disable signals before calling.
 *
 * FIXME: flags for relative/abs motion?
 *
 * @param device The device to generate the event for
 * @param type Event type, one of KeyPress or KeyRelease
 * @param keycode Key code of the pressed/released key
 * @param mask Valuator mask for valuators present for this event.
 *
 */
void
QueueKeyboardEvents(DeviceIntPtr device, int type,
                    int keycode, const ValuatorMask *mask)
{
    int nevents;

    nevents = GetKeyboardEvents(InputEventList, device, type, keycode, mask);
    queueEventList(device, InputEventList, nevents);
}

/**
 * Returns a set of InternalEvents for KeyPress/KeyRelease, optionally
 * also with valuator events.
 *
 * The DDX is responsible for allocating the event list in the first
 * place via InitEventList(), and for freeing it.
 *
 * @return the number of events written into events.
 */
int
GetKeyboardEvents(InternalEvent *events, DeviceIntPtr pDev, int type,
                  int key_code, const ValuatorMask *mask_in)
{
    int num_events = 0;
    CARD32 ms = 0;
    DeviceEvent *event;
    RawDeviceEvent *raw;
    ValuatorMask mask;

    /* refuse events from disabled devices */
    if (!pDev->enabled)
        return 0;

    if (!events || !pDev->key || !pDev->focus || !pDev->kbdfeed ||
        (type != KeyPress && type != KeyRelease) ||
        (key_code < 8 || key_code > 255))
        return 0;

    if (mask_in && valuator_mask_size(mask_in) > 1) {
        ErrorF("[dix] the server does not handle valuator masks with "
               "keyboard events. This is a bug. You may fix it.\n");
    }

    num_events = 1;

    events =
        UpdateFromMaster(events, pDev, DEVCHANGE_KEYBOARD_EVENT, &num_events);

    /* Handle core repeating, via press/release/press/release. */
    if (type == KeyPress && key_is_down(pDev, key_code, KEY_POSTED)) {
        /* If autorepeating is disabled either globally or just for that key,
         * or we have a modifier, don't generate a repeat event. */
        if (!pDev->kbdfeed->ctrl.autoRepeat ||
            !key_autorepeats(pDev, key_code) ||
            pDev->key->xkbInfo->desc->map->modmap[key_code])
            return 0;
    }

    ms = GetTimeInMillis();

    raw = &events->raw_event;
    events++;
    num_events++;

    valuator_mask_copy(&mask, mask_in);

    init_raw(pDev, raw, ms, type, key_code);
    set_raw_valuators(raw, &mask, raw->valuators.data_raw);

    clipValuators(pDev, &mask);

    set_raw_valuators(raw, &mask, raw->valuators.data);

    event = &events->device_event;
    init_device_event(event, pDev, ms);
    event->detail.key = key_code;

    if (type == KeyPress) {
        event->type = ET_KeyPress;
        set_key_down(pDev, key_code, KEY_POSTED);
    }
    else if (type == KeyRelease) {
        event->type = ET_KeyRelease;
        set_key_up(pDev, key_code, KEY_POSTED);
    }

    clipValuators(pDev, &mask);

    set_valuators(pDev, event, &mask);

    if (!IsFloating(pDev)) {
        DeviceIntPtr master = GetMaster(pDev, MASTER_POINTER);

        event_set_root_coordinates(event,
                                   master->last.valuators[0],
                                   master->last.valuators[1]);
    }

    return num_events;
}

/**
 * Initialize an event array large enough for num_events arrays.
 * This event list is to be passed into GetPointerEvents() and
 * GetKeyboardEvents().
 *
 * @param num_events Number of elements in list.
 */
InternalEvent *
InitEventList(int num_events)
{
    InternalEvent *events = calloc(num_events, sizeof(InternalEvent));

    return events;
}

/**
 * Free an event list.
 *
 * @param list The list to be freed.
 * @param num_events Number of elements in list.
 */
void
FreeEventList(InternalEvent *list, int num_events)
{
    free(list);
}

/**
 * Transform vector x/y according to matrix m and drop the rounded coords
 * back into x/y.
 */
static void
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 = p.v[0];
    *y = p.v[1];
}

/**
 * Apply the device's transformation matrix to the valuator mask and replace
 * the scaled values in mask. This transformation only applies to valuators
 * 0 and 1, others will be untouched.
 *
 * @param dev The device the valuators came from
 * @param[in,out] mask The valuator mask.
 */
static void
transformAbsolute(DeviceIntPtr dev, ValuatorMask *mask)
{
    double x, y, ox, oy;
    int has_x, has_y;

    has_x = valuator_mask_fetch_double(mask, 0, &ox);
    has_y = valuator_mask_fetch_double(mask, 1, &oy);

    if (!has_x && !has_y)
        return;

    if (!has_x || !has_y) {
        struct pixman_f_transform invert;

        /* undo transformation from last event */
        ox = dev->last.valuators[0];
        oy = dev->last.valuators[1];

        pixman_f_transform_invert(&invert, &dev->transform);
        transform(&invert, &ox, &oy);

        x = ox;
        y = oy;
    }

    if (valuator_mask_isset(mask, 0))
        ox = x = valuator_mask_get_double(mask, 0);

    if (valuator_mask_isset(mask, 1))
        oy = y = valuator_mask_get_double(mask, 1);

    transform(&dev->transform, &x, &y);

    if (valuator_mask_isset(mask, 0) || ox != x)
        valuator_mask_set_double(mask, 0, x);

    if (valuator_mask_isset(mask, 1) || oy != y)
        valuator_mask_set_double(mask, 1, y);
}

static void
storeLastValuators(DeviceIntPtr dev, ValuatorMask *mask,
                   int xaxis, int yaxis, double devx, double devy)
{
    int i;

    /* store desktop-wide in last.valuators */
    if (valuator_mask_isset(mask, xaxis))
        dev->last.valuators[0] = devx;
    if (valuator_mask_isset(mask, yaxis))
        dev->last.valuators[1] = devy;

    for (i = 0; i < valuator_mask_size(mask); i++) {
        if (i == xaxis || i == yaxis)
            continue;

        if (valuator_mask_isset(mask, i))
            dev->last.valuators[i] = valuator_mask_get_double(mask, i);
    }

}

/**
 * Generate internal events representing this pointer event and enqueue them
 * on the event queue.
 *
 * This function is not reentrant. Disable signals before calling.
 *
 * @param device The device to generate the event for
 * @param type Event type, one of ButtonPress, ButtonRelease, MotionNotify
 * @param buttons Button number of the buttons modified. Must be 0 for
 * MotionNotify
 * @param flags Event modification flags
 * @param mask Valuator mask for valuators present for this event.
 */
void
QueuePointerEvents(DeviceIntPtr device, int type,
                   int buttons, int flags, const ValuatorMask *mask)
{
    int nevents;

    nevents =
        GetPointerEvents(InputEventList, device, type, buttons, flags, mask);
    queueEventList(device, InputEventList, nevents);
}

/**
 * Helper function for GetPointerEvents, which only generates motion and
 * raw motion events for the slave device: does not update the master device.
 *
 * Should not be called by anyone other than GetPointerEvents.
 *
 * We use several different coordinate systems and need to switch between
 * the three in fill_pointer_events, positionSprite and
 * miPointerSetPosition. "desktop" refers to the width/height of all
 * screenInfo.screens[n]->width/height added up. "screen" is ScreenRec, not
 * output.
 *
 * Coordinate systems:
 * - relative events have a mask_in in relative coordinates, mapped to
 *   pixels. These events are mapped to the current position±delta.
 * - absolute events have a mask_in in absolute device coordinates in
 *   device-specific range. This range is mapped to the desktop.
 * - POINTER_SCREEN absolute events (x86WarpCursor) are in screen-relative
 *   screen coordinate range.
 * - rootx/rooty in events must be be relative to the current screen's
 *   origin (screen coordinate system)
 * - XI2 valuators must be relative to the current screen's origin. On
 *   the protocol the device min/max range maps to the current screen.
 *
 * For screen switching we need to get the desktop coordinates for each
 * event, then map that to the respective position on each screen and
 * position the cursor there.
 * The device's last.valuator[] stores the last position in desktop-wide
 * coordinates (in device range for slave devices, desktop range for master
 * devices).
 *
 * screen-relative device coordinates requires scaling: A device coordinate
 * x/y of range [n..m] that maps to positions Sx/Sy on Screen S must be
 * rescaled to match Sx/Sy for [n..m]. In the simplest example, x of (m/2-1)
 * is the last coordinate on the first screen and must be rescaled for the
 * event to be m. XI2 clients that do their own coordinate mapping would
 * otherwise interpret the position of the device elsewere to the cursor.
 *
 * @return the number of events written into events.
 */
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;
    DeviceEvent *event;
    RawDeviceEvent *raw;
    double screenx = 0.0, screeny = 0.0;        /* desktop coordinate system */
    double devx = 0.0, devy = 0.0;      /* desktop-wide in device coords */
    ValuatorMask mask;
    ScreenPtr scr;

    switch (type) {
    case MotionNotify:
        if (!pDev->valuator) {
            ErrorF("[dix] motion events from device %d without valuators\n",
                   pDev->id);
            return 0;
        }
        if (!mask_in || valuator_mask_num_valuators(mask_in) <= 0)
            return 0;
        break;
    case ButtonPress:
    case ButtonRelease:
        if (!pDev->button || !buttons)
            return 0;
        if (mask_in && valuator_mask_size(mask_in) > 0 && !pDev->valuator) {
            ErrorF
                ("[dix] button event with valuator from device %d without valuators\n",
                 pDev->id);
            return 0;
        }
        break;
    default:
        return 0;
    }

    valuator_mask_copy(&mask, mask_in);

    if ((flags & POINTER_NORAW) == 0) {
        raw = &events->raw_event;
        events++;
        num_events++;

        init_raw(pDev, raw, ms, type, buttons);
        set_raw_valuators(raw, &mask, raw->valuators.data_raw);
    }

    /* valuators are in driver-native format (rel or abs) */

    if (flags & POINTER_ABSOLUTE) {
        if (flags & POINTER_SCREEN)     /* valuators are in screen coords */
            scale_from_screen(pDev, &mask);

        transformAbsolute(pDev, &mask);
        clipAbsolute(pDev, &mask);
        if ((flags & POINTER_NORAW) == 0)
            set_raw_valuators(raw, &mask, raw->valuators.data);
    }
    else {
        if (flags & POINTER_ACCELERATE)
            accelPointer(pDev, &mask, ms);
        if ((flags & POINTER_NORAW) == 0)
            set_raw_valuators(raw, &mask, raw->valuators.data);

        moveRelative(pDev, &mask);
    }

    /* valuators are in device coordinate system in absolute coordinates */
    scale_to_desktop(pDev, &mask, &devx, &devy, &screenx, &screeny);
    scr = positionSprite(pDev, (flags & POINTER_ABSOLUTE) ? Absolute : Relative,
                         &mask, &devx, &devy, &screenx, &screeny);

    /* screenx, screeny are in desktop coordinates,
       mask is in device coordinates per-screen (the event data)
       devx/devy is in device coordinate desktop-wide */
    updateHistory(pDev, &mask, ms);

    clipValuators(pDev, &mask);

    storeLastValuators(pDev, &mask, 0, 1, devx, devy);

    /* Update the MD's co-ordinates, which are always in desktop space. */
    if (!IsMaster(pDev) && !IsFloating(pDev)) {
        DeviceIntPtr master = GetMaster(pDev, MASTER_POINTER);

        master->last.valuators[0] = screenx;
        master->last.valuators[1] = screeny;
    }

    event = &events->device_event;
    init_device_event(event, pDev, ms);

    if (type == MotionNotify) {
        event->type = ET_Motion;
        event->detail.button = 0;
    }
    else {
        if (type == ButtonPress) {
            event->type = ET_ButtonPress;
            set_button_down(pDev, buttons, BUTTON_POSTED);
        }
        else if (type == ButtonRelease) {
            event->type = ET_ButtonRelease;
            set_button_up(pDev, buttons, BUTTON_POSTED);
        }
        event->detail.button = buttons;
    }

    /* root_x and root_y must be in per-screen co-ordinates */
    event_set_root_coordinates(event, screenx - scr->x, screeny - scr->y);

    if (flags & POINTER_EMULATED) {
        raw->flags = XIPointerEmulated;
        event->flags = XIPointerEmulated;
    }

    set_valuators(pDev, event, &mask);

    return num_events;
}

/**
 * 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 type The real type of the event
 * @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 type,
                             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;
    int flags = 0;

    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 (type != ButtonPress && type != ButtonRelease)
        flags |= POINTER_EMULATED;

    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) {
            if (type != ButtonRelease) {
                nev_tmp = fill_pointer_events(events, dev, ButtonPress, b, ms,
                                              flags, NULL);
                events += nev_tmp;
                num_events += nev_tmp;
            }
            if (type != ButtonPress) {
                nev_tmp = fill_pointer_events(events, dev, ButtonRelease, b, ms,
                                              flags, 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;
    ValuatorMask mask;
    ValuatorMask scroll;
    int i;
    int realtype = type;

    /* 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 adj;
        int axis;
        int h_scroll_axis = -1;
        int v_scroll_axis = -1;

        if (pDev->valuator) {
            h_scroll_axis = pDev->valuator->h_scroll_axis;
            v_scroll_axis = pDev->valuator->v_scroll_axis;
        }

        /* Up is negative on valuators, down positive */
        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;
            add_to_scroll_valuator(pDev, &mask, axis, adj);
            type = MotionNotify;
            buttons = 0;
            flags |= POINTER_EMULATED;
        }
    }

    /* 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 ( !pDev->valuator || (i >= pDev->valuator->numAxes))
            break;

        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, realtype, 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.
 *
 * This function is not reentrant. Disable signals before calling.
 *
 * @param device The device to generate the event for
 * @param type Event type, one of ProximityIn or ProximityOut
 * @param keycode Key code of the pressed/released key
 * @param mask Valuator mask for valuators present for this event.
 *
 */
void
QueueProximityEvents(DeviceIntPtr device, int type, const ValuatorMask *mask)
{
    int nevents;

    nevents = GetProximityEvents(InputEventList, device, type, mask);
    queueEventList(device, InputEventList, nevents);
}

/**
 * Generate ProximityIn/ProximityOut InternalEvents, accompanied by
 * valuators.
 *
 * The DDX is responsible for allocating the events in the first place via
 * InitEventList(), and for freeing it.
 *
 * @return the number of events written into events.
 */
int
GetProximityEvents(InternalEvent *events, DeviceIntPtr pDev, int type,
                   const ValuatorMask *mask_in)
{
    int num_events = 1, i;
    DeviceEvent *event;
    ValuatorMask mask;

    /* refuse events from disabled devices */
    if (!pDev->enabled)
        return 0;

    /* Sanity checks. */
    if ((type != ProximityIn && type != ProximityOut) || !mask_in)
        return 0;
    if (!pDev->valuator || !pDev->proximity)
        return 0;

    valuator_mask_copy(&mask, mask_in);

    /* ignore relative axes for proximity. */
    for (i = 0; i < valuator_mask_size(&mask); i++) {
        if (valuator_mask_isset(&mask, i) &&
            valuator_get_mode(pDev, i) == Relative)
            valuator_mask_unset(&mask, i);
    }

    /* FIXME: posting proximity events with relative valuators only results
     * in an empty event, EventToXI() will fail to convert → no event sent
     * to client. */

    events =
        UpdateFromMaster(events, pDev, DEVCHANGE_POINTER_EVENT, &num_events);

    event = &events->device_event;
    init_device_event(event, pDev, GetTimeInMillis());
    event->type = (type == ProximityIn) ? ET_ProximityIn : ET_ProximityOut;

    clipValuators(pDev, &mask);

    set_valuators(pDev, event, &mask);

    return num_events;
}

int
GetTouchOwnershipEvents(InternalEvent *events, DeviceIntPtr pDev,
                        TouchPointInfoPtr ti, uint8_t reason, XID resource,
                        uint32_t flags)
{
    TouchClassPtr t = pDev->touch;
    TouchOwnershipEvent *event;
    CARD32 ms = GetTimeInMillis();

    if (!pDev->enabled || !t || !ti)
        return 0;

    event = &events->touch_ownership_event;
    init_touch_ownership(pDev, event, ms);

    event->touchid = ti->client_id;
    event->sourceid = ti->sourceid;
    event->resource = resource;
    event->flags = flags;
    event->reason = reason;

    return 1;
}

/**
 * Generate internal events representing this touch event and enqueue them
 * on the event queue.
 *
 * This function is not reentrant. Disable signals before calling.
 *
 * @param device The device to generate the event for
 * @param type Event type, one of XI_TouchBegin, XI_TouchUpdate, XI_TouchEnd
 * @param touchid Touch point ID
 * @param flags Event modification flags
 * @param mask Valuator mask for valuators present for this event.
 */
void
QueueTouchEvents(DeviceIntPtr device, int type,
                 uint32_t ddx_touchid, int flags, const ValuatorMask *mask)
{
    int nevents;

    nevents =
        GetTouchEvents(InputEventList, device, ddx_touchid, type, flags, mask);
    queueEventList(device, InputEventList, nevents);
}

/**
 * Get events for a touch. Generates a TouchBegin event if end is not set and
 * the touch id is not active. Generates a TouchUpdate event if end is not set
 * and the touch id is active. Generates a TouchEnd event if end is set and the
 * touch id is active.
 *
 * 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 GetMaximumEventsNum(), and for freeing it.
 *
 * @param[out] events The list of events generated
 * @param dev The device to generate the events for
 * @param ddx_touchid The touch ID as assigned by the DDX
 * @param type XI_TouchBegin, XI_TouchUpdate or XI_TouchEnd
 * @param flags Event flags
 * @param mask_in Valuator information for this event
 */
int
GetTouchEvents(InternalEvent *events, DeviceIntPtr dev, uint32_t ddx_touchid,
               uint16_t type, uint32_t flags, const ValuatorMask *mask_in)
{
    ScreenPtr scr = dev->spriteInfo->sprite->hotPhys.pScreen;
    TouchClassPtr t = dev->touch;
    ValuatorClassPtr v = dev->valuator;
    DeviceEvent *event;
    CARD32 ms = GetTimeInMillis();
    ValuatorMask mask;
    double screenx = 0.0, screeny = 0.0;        /* desktop coordinate system */
    double devx = 0.0, devy = 0.0;      /* desktop-wide in device coords */
    int i;
    int num_events = 0;
    RawDeviceEvent *raw;
    union touch {
        TouchPointInfoPtr dix_ti;
        DDXTouchPointInfoPtr ti;
    } touchpoint;
    int need_rawevent = TRUE;
    Bool emulate_pointer = FALSE;
    int client_id = 0;

    if (!dev->enabled || !t || !v)
        return 0;

    /* Find and/or create the DDX touch info */

    if (flags & TOUCH_CLIENT_ID) {      /* A DIX-submitted TouchEnd */
        touchpoint.dix_ti = TouchFindByClientID(dev, ddx_touchid);
        BUG_WARN(!touchpoint.dix_ti);

        if (!touchpoint.dix_ti)
            return 0;

        if (!mask_in ||
            !valuator_mask_isset(mask_in, 0) ||
            !valuator_mask_isset(mask_in, 1)) {
            ErrorF
                ("[dix] dix-submitted events must have x/y valuator information.\n");
            return 0;
        }

        need_rawevent = FALSE;
        client_id = touchpoint.dix_ti->client_id;
    }
    else {                      /* a DDX-submitted touch */

        touchpoint.ti =
            TouchFindByDDXID(dev, ddx_touchid, (type == XI_TouchBegin));
        if (!touchpoint.ti) {
            ErrorF("[dix] %s: unable to %s touch point %x\n", dev->name,
                   type == XI_TouchBegin ? "begin" : "find", ddx_touchid);
            return 0;
        }
        client_id = touchpoint.ti->client_id;
    }

    if (!(flags & TOUCH_CLIENT_ID))
        emulate_pointer = touchpoint.ti->emulate_pointer;
    else
        emulate_pointer = ! !(flags & TOUCH_POINTER_EMULATED);

    if (!IsMaster(dev))
        events =
            UpdateFromMaster(events, dev, DEVCHANGE_POINTER_EVENT, &num_events);

    valuator_mask_copy(&mask, mask_in);

    if (need_rawevent) {
        raw = &events->raw_event;
        events++;
        num_events++;
        init_raw(dev, raw, ms, type, client_id);
        set_raw_valuators(raw, &mask, raw->valuators.data_raw);
    }

    event = &events->device_event;
    num_events++;

    init_event(dev, event, ms);
    /* if submitted for master device, get the sourceid from there */
    if (flags & TOUCH_CLIENT_ID) {
        event->sourceid = touchpoint.dix_ti->sourceid;
        /* TOUCH_CLIENT_ID implies norawevent */
    }

    switch (type) {
    case XI_TouchBegin:
        event->type = ET_TouchBegin;
        /* If we're starting a touch, we must have x & y co-ordinates. */
        if (!mask_in ||
            !valuator_mask_isset(mask_in, 0) ||
            !valuator_mask_isset(mask_in, 1)) {
            ErrorF("%s: Attempted to start touch without x/y (driver bug)\n",
                   dev->name);
            return 0;
        }
        break;
    case XI_TouchUpdate:
        event->type = ET_TouchUpdate;
        if (!mask_in || valuator_mask_num_valuators(mask_in) <= 0) {
            ErrorF("%s: TouchUpdate with no valuators? Driver bug\n",
                   dev->name);
        }
        break;
    case XI_TouchEnd:
        event->type = ET_TouchEnd;
        /* We can end the DDX touch here, since we don't use the active
         * field below */
        if (!(flags & TOUCH_CLIENT_ID))
            TouchEndDDXTouch(dev, touchpoint.ti);
        break;
    default:
        return 0;
    }
    if (t->mode == XIDirectTouch && !(flags & TOUCH_CLIENT_ID)) {
        if (!valuator_mask_isset(&mask, 0))
            valuator_mask_set_double(&mask, 0,
                                     valuator_mask_get_double(touchpoint.ti->
                                                              valuators, 0));
        if (!valuator_mask_isset(&mask, 1))
            valuator_mask_set_double(&mask, 1,
                                     valuator_mask_get_double(touchpoint.ti->
                                                              valuators, 1));
    }

    /* Get our screen event co-ordinates (root_x/root_y/event_x/event_y):
     * these come from the touchpoint in Absolute mode, or the sprite in
     * Relative. */
    if (t->mode == XIDirectTouch) {
        transformAbsolute(dev, &mask);

        if (!(flags & TOUCH_CLIENT_ID)) {
            for (i = 0; i < valuator_mask_size(&mask); i++) {
                double val;

                if (valuator_mask_fetch_double(&mask, i, &val))
                    valuator_mask_set_double(touchpoint.ti->valuators, i, val);
            }
        }

        clipAbsolute(dev, &mask);
    }
    else {
        screenx = dev->spriteInfo->sprite->hotPhys.x;
        screeny = dev->spriteInfo->sprite->hotPhys.y;
    }
    if (need_rawevent)
        set_raw_valuators(raw, &mask, raw->valuators.data);

    /* Indirect device touch coordinates are not used for cursor positioning.
     * They are merely informational, and are provided in device coordinates.
     * The device sprite is used for positioning instead, and it is already
     * scaled. */
    if (t->mode == XIDirectTouch)
        scr = scale_to_desktop(dev, &mask, &devx, &devy, &screenx, &screeny);
    if (emulate_pointer)
        scr = positionSprite(dev, Absolute, &mask,
                             &devx, &devy, &screenx, &screeny);

    /* see fill_pointer_events for coordinate systems */
    if (emulate_pointer)
        updateHistory(dev, &mask, ms);

    clipValuators(dev, &mask);

    if (emulate_pointer)
        storeLastValuators(dev, &mask, 0, 1, devx, devy);

    event->root = scr->root->drawable.id;

    event_set_root_coordinates(event, screenx, screeny);
    event->touchid = client_id;
    event->flags = flags;

    if (emulate_pointer) {
        event->flags |= TOUCH_POINTER_EMULATED;
        event->detail.button = 1;
    }

    set_valuators(dev, event, &mask);
    for (i = 0; i < v->numAxes; i++) {
        if (valuator_mask_isset(&mask, i))
            v->axisVal[i] = valuator_mask_get(&mask, i);
    }

    return num_events;
}

/**
 * Synthesize a single motion event for the core pointer.
 *
 * Used in cursor functions, e.g. when cursor confinement changes, and we need
 * to shift the pointer to get it inside the new bounds.
 */
void
PostSyntheticMotion(DeviceIntPtr pDev,
                    int x, int y, int screen, unsigned long time)
{
    DeviceEvent ev;

#ifdef PANORAMIX
    /* Translate back to the sprite screen since processInputProc
       will translate from sprite screen to screen 0 upon reentry
       to the DIX layer. */
    if (!noPanoramiXExtension) {
        x += screenInfo.screens[0]->x - screenInfo.screens[screen]->x;
        y += screenInfo.screens[0]->y - screenInfo.screens[screen]->y;
    }
#endif

    memset(&ev, 0, sizeof(DeviceEvent));
    init_device_event(&ev, pDev, time);
    ev.root_x = x;
    ev.root_y = y;
    ev.type = ET_Motion;
    ev.time = time;

    /* FIXME: MD/SD considerations? */
    (*pDev->public.processInputProc) ((InternalEvent *) &ev, pDev);
}