[PATCH libinput 3/3] tools: add a tool to measure touch pressure
Peter Hutterer
peter.hutterer at who-t.net
Fri Jun 30 01:00:58 UTC 2017
And update the documentation for how to use the new tool. It's much more
interactive than evemu and easier to grasp, so let's advertise that.
Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
doc/touchpad-pressure.dox | 78 ++++----
meson.build | 9 +
tools/libinput-measure-touchpad-pressure | 259 +++++++++++++++++++++++++++
tools/libinput-measure-touchpad-pressure.man | 63 +++++++
tools/libinput-measure.man | 3 +
tools/libinput.man | 3 +
6 files changed, 367 insertions(+), 48 deletions(-)
create mode 100755 tools/libinput-measure-touchpad-pressure
create mode 100644 tools/libinput-measure-touchpad-pressure.man
diff --git a/doc/touchpad-pressure.dox b/doc/touchpad-pressure.dox
index 742b19f9..b51e6e5d 100644
--- a/doc/touchpad-pressure.dox
+++ b/doc/touchpad-pressure.dox
@@ -47,62 +47,44 @@ locally. Note that the hwdb entry is **not public API** and **may change at
any time**. Users are advised to @ref reporting_bugs "report a bug" with the
updated pressure ranges when testing has completed.
-First, install the "evemu" package providing the ```evemu-record``` tool.
-Run ```evemu-record``` as root (without arguments) to see a list of devices
-and select the touchpad device. Pipe the actual output of the tool into a
-file for later analysis. For example:
+Use the ```libinput measure touchpad-pressure``` tool provided by libinput.
+This tool will search for your touchpad device and print some pressure
+statistics, including whether a touch is/was considered logically down.
+Example output of the tool is below:
<pre>
-$ sudo evemu-record > touchpad-pressure.txt
-Available devices:
-/dev/input/event0: Lid Switch
-/dev/input/event1: Sleep Button
-/dev/input/event2: Power Button
-/dev/input/event3: AT Translated Set 2 keyboard
-/dev/input/event4: SynPS/2 Synaptics TouchPad
-/dev/input/event5: ELAN Touchscreen
-[...]
-Select the device event number [0-19]: 4
-# Ctrl+C to quit, the output will be in touchpad-pressure.txt
+$ sudo libinput measure touchpad-pressure
+Ready for recording data.
+Pressure range used: 8:10
+Palm pressure range used: 65535
+Place a single finger on the touchpad to measure pressure values.
+Ctrl+C to exit
+
+Sequence 1190 pressure: min: 39 max: 48 avg: 43 median: 44 tags: down
+Sequence 1191 pressure: min: 49 max: 65 avg: 62 median: 64 tags: down
+Sequence 1192 pressure: min: 40 max: 78 avg: 64 median: 66 tags: down
+Sequence 1193 pressure: min: 36 max: 83 avg: 70 median: 73 tags: down
+Sequence 1194 pressure: min: 43 max: 76 avg: 72 median: 74 tags: down
+Touchpad pressure: 47 min: 47 max: 86 tags: down
</pre>
-Now move a finger at **normal pressure** several times around the touchpad,
-as if moving the cursor normally around the screen. Avoid any accidental
-palm touches or any excessive or light pressure.
+The example output shows five completed touch sequences and one ongoing one.
+For each, the respective minimum and maximum pressure values are printed as
+well as some statistics. The ```tags``` show that sequence was considered
+logically down at some point. This is an interactive tool and its output may
+change frequently. Refer to the <i>libinput-measure-touchpad-pressure(1)</i> man
+page for more details.
-The event recording is then filtered for pressure information, which is
-sorted and exported to a new file:
+By default, this tool uses the udev hwdb entries for the pressure range. To
+narrow down on the best values for your device, specify the 'logically down'
+and 'logically up' pressure thresholds with the ```--touch-thresholds``
+argument:
<pre>
-$ grep --only-matching "ABS_MT_PRESSURE[ ]*[0-9]*" touchpad-pressure.txt | \
- sed -e "s/ABS_MT_PRESSURE[ ]*//" | \
- sort -n | uniq -c > touchpad-pressure-statistics.txt
+$ sudo libinput measure touchpad-pressure --touch-thresholds=10:8
</pre>
-The file contains a list of (count, pressure-value) tuples which can be
-visualized with gnuplot. Copy the following into a file named
-```touchpad-pressure-statistics.gnuplot```:
-
-<pre>
-set style data lines
-plot 'touchpad-pressure-statistics.txt' using 2:1
-pause -1
-</pre>
-
-Now, you can visualize the touchpad pressure curve with the following
-command:
-<pre>
-$ gnuplot touchpad-pressure-statistics.gnuplot
-</pre>
-
-The visualization will show a curve with the various pressure ranges, see
-[this bugzilla attachment](https://bugs.freedesktop.org/attachment.cgi?id=130659).
-In most cases, the thresholds can be guessed based on this curve. libinput
-employes a [Schmitt trigger](https://en.wikipedia.org/wiki/Schmitt_trigger)
-with an upper threshold and a lower threshold. A touch is detected when the
-pressure goes above the high threshold, a release is detected when the
-pressure fallse below the low threshold. Thus, an ideal threshold
-combination is with a high threshold slightly above the minimum threshold, a
-low threshold on the minimum threshold.
+Interact with the touchpad and check if the output of this tool matches your
+expectations.
Once the thresholds are decided on (e.g. 10 and 8), they can be enabled with
the following hwdb file:
diff --git a/meson.build b/meson.build
index bc639718..990e6add 100644
--- a/meson.build
+++ b/meson.build
@@ -421,6 +421,15 @@ configure_file(input : 'tools/libinput-measure-touchpad-tap.man',
install_dir : join_paths(get_option('mandir'), 'man1')
)
+install_data('tools/libinput-measure-touchpad-pressure',
+ install_dir : libinput_tool_path)
+configure_file(input : 'tools/libinput-measure-touchpad-pressure.man',
+ output : 'libinput-measure-touchpad-pressure.1',
+ configuration : man_config,
+ install : true,
+ install_dir : join_paths(get_option('mandir'), 'man1')
+ )
+
if get_option('debug-gui')
dep_gtk = dependency('gtk+-3.0')
dep_cairo = dependency('cairo')
diff --git a/tools/libinput-measure-touchpad-pressure b/tools/libinput-measure-touchpad-pressure
new file mode 100755
index 00000000..6e827801
--- /dev/null
+++ b/tools/libinput-measure-touchpad-pressure
@@ -0,0 +1,259 @@
+#!/usr/bin/env python3
+#
+# Copyright © 2017 Red Hat, Inc.
+#
+# 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.
+#
+
+import sys
+import argparse
+import evdev
+import evdev.ecodes
+import pyudev
+
+class Range(object):
+ """Class to keep a min/max of a value around"""
+ def __init__(self):
+ self.min = float('inf')
+ self.max = float('-inf')
+
+ def update(self, value):
+ self.min = min(self.min, value)
+ self.max = max(self.max, value)
+
+class Touch(object):
+ """A single data point of a sequence (i.e. one event frame)"""
+
+ def __init__(self, pressure=None):
+ self.pressure = pressure
+
+class TouchSequence(object):
+ """A touch sequence from beginning to end"""
+
+ def __init__(self, device, tracking_id):
+ self.device = device
+ self.tracking_id = tracking_id
+ self.points = []
+
+ self.is_active = True
+
+ self.is_down = False
+ self.was_down = False
+ self.is_palm = False
+ self.was_palm = False
+
+ self.prange = Range()
+
+ def append(self, touch):
+ """Add a Touch to the sequence"""
+ self.points.append(touch)
+ self.prange.update(touch.pressure)
+
+ if touch.pressure < self.device.up:
+ self.is_down = False
+ elif touch.pressure > self.device.down:
+ self.is_down = True
+ self.was_down = True
+
+ self.is_palm = touch.pressure > self.device.palm
+ if self.is_palm:
+ self.was_palm = True
+
+ def finalize(self):
+ """Mark the TouchSequence as complete (finger is up)"""
+ self.is_active = False
+
+ def avg(self):
+ """Average pressure value of this sequence"""
+ return int(sum([p.pressure for p in self.points])/len(self.points))
+
+ def median(self):
+ """Median pressure value of this sequence"""
+ ps = sorted([p.pressure for p in self.points])
+ idx = int(len(self.points)/2)
+ return ps[idx]
+
+ def __str__(self):
+ return self._str_state() if self.is_active else self._str_summary()
+
+ def _str_summary(self):
+ s = "Sequence {} pressure: min: {:3d} max: {:3d} avg: {:3d} median: {:3d} tags:".format(
+ self.tracking_id,
+ self.prange.min,
+ self.prange.max,
+ self.avg(),
+ self.median())
+ if self.was_down:
+ s += " down"
+ if self.was_palm:
+ s += " palm"
+
+ return s
+
+ def _str_state(self):
+ s = "Touchpad pressure: {:3d} min: {:3d} max: {:3d} tags: {} {}".format(
+ self.points[-1].pressure,
+ self.prange.min,
+ self.prange.max,
+ "down" if self.is_down else " ",
+ "palm" if self.is_palm else " "
+ )
+ return s
+
+class InvalidDeviceError(Exception):
+ pass
+
+class Device(object):
+ def __init__(self, path):
+ if path is None:
+ self.path = self.find_touchpad_device()
+ else:
+ self.path = path
+
+ self.device = evdev.InputDevice(self.path)
+ # capabilities rturns a dict with the EV_* codes as key,
+ # each of which is a list of tuples of (code, AbsInfo)
+ #
+ # Get the abs list first (or empty list if missing),
+ # then extract the pressure absinfo from that
+ caps = self.device.capabilities(absinfo=True).get(evdev.ecodes.EV_ABS, [])
+ p = [cap[1] for cap in caps if cap[0] == evdev.ecodes.ABS_MT_PRESSURE]
+ if not p:
+ raise InvalidDeviceError("device does not have ABS_MT_PRESSURE")
+
+ p = p[0]
+ prange = p.max - p.min
+
+ # libinput defaults
+ self.up = int(p.min + 0.12 * prange)
+ self.down = int(p.min + 0.10 * prange)
+ self.palm = 130 # the libinput default
+
+ self._init_thresholds_from_udev()
+ self.sequences = []
+
+ def find_touchpad_device(self):
+ context = pyudev.Context()
+ for device in context.list_devices(subsystem='input'):
+ if not device.get('ID_INPUT_TOUCHPAD', 0):
+ continue
+
+ if not device.device_node or not device.device_node.startswith('/dev/input/event'):
+ continue
+
+ return device.device_node
+ print("Unable to find a touchpad device.", file=sys.stderr)
+ sys.exit(1)
+
+ def _init_thresholds_from_udev(self):
+ context = pyudev.Context()
+ ud = pyudev.Devices.from_device_file(context, self.path)
+ v = ud.get('LIBINPUT_ATTR_PRESSURE_RANGE')
+ if v:
+ self.up, self.down = colon_tuple(v)
+
+ v = ud.get('LIBINPUT_ATTR_PALM_PRESSURE_THRESHOLD')
+ if v:
+ self.palm = int(v)
+
+ def start_new_sequence(self, tracking_id):
+ self.sequences.append(TouchSequence(self, tracking_id))
+
+ def current_sequence(self):
+ return self.sequences[-1]
+
+def handle_key(device, event):
+ tapcodes = [evdev.ecodes.BTN_TOOL_DOUBLETAP,
+ evdev.ecodes.BTN_TOOL_TRIPLETAP,
+ evdev.ecodes.BTN_TOOL_QUADTAP,
+ evdev.ecodes.BTN_TOOL_QUINTTAP]
+ if event.code in tapcodes and event.value > 0:
+ print("\rThis tool cannot handle multiple fingers, output will be invalid", file=sys.stderr)
+
+def handle_abs(device, event):
+ if event.code == evdev.ecodes.ABS_MT_TRACKING_ID:
+ if event.value > -1:
+ device.start_new_sequence(event.value)
+ else:
+ s = device.current_sequence()
+ s.finalize()
+ print("\r{}".format(s))
+ elif event.code == evdev.ecodes.ABS_MT_PRESSURE:
+ s = device.current_sequence()
+ s.append(Touch(pressure=event.value))
+ print("\r{}".format(s), end="")
+
+def handle_event(device, event):
+ if event.type == evdev.ecodes.EV_ABS:
+ handle_abs(device, event)
+ elif event.type == evdev.ecodes.EV_KEY:
+ handle_key(device, event)
+
+def loop(device):
+ print("Ready for recording data.")
+ print("Pressure range used: {}:{}".format(device.down, device.up))
+ print("Palm pressure range used: {}".format(device.palm))
+ print("Place a single finger on the touchpad to measure pressure values.\n"
+ "Ctrl+C to exit\n")
+
+ for event in device.device.read_loop():
+ handle_event(device, event)
+
+def colon_tuple(string):
+ try:
+ ts = string.split(':')
+ t = tuple([int(x) for x in ts])
+ if len(t) == 2 and t[0] >= t[1]:
+ return t
+ except:
+ pass
+
+ msg = "{} is not in format N:M (N >= M)".format(string)
+ raise argparse.ArgumentTypeError(msg)
+
+def main(args):
+ parser = argparse.ArgumentParser(description="Measure touchpad pressure values")
+ parser.add_argument('path', metavar='/dev/input/event0',
+ nargs='?', type=str, help='Path to device (optional)' )
+ parser.add_argument('--touch-thresholds', metavar='down:up',
+ type=colon_tuple, help='Thresholds when a touch is logically down or up')
+ parser.add_argument('--palm-threshold', metavar='t',
+ type=int, help='Threshold when a touch is a palm')
+ args = parser.parse_args()
+
+ try:
+ device = Device(args.path)
+
+ if args.touch_thresholds is not None:
+ device.down, device.up = args.touch_thresholds
+
+ if args.palm_threshold is not None:
+ device.palm = args.palm_threshold
+
+ loop(device)
+ except KeyboardInterrupt:
+ pass
+ except (PermissionError, OSError):
+ print("Error: failed to open device")
+ except InvalidDeviceError as e:
+ print("Error: {}".format(e))
+
+if __name__ == "__main__":
+ main(sys.argv)
diff --git a/tools/libinput-measure-touchpad-pressure.man b/tools/libinput-measure-touchpad-pressure.man
new file mode 100644
index 00000000..67f0d687
--- /dev/null
+++ b/tools/libinput-measure-touchpad-pressure.man
@@ -0,0 +1,63 @@
+.TH libinput-measure-touchpad-pressure "1"
+.SH NAME
+libinput\-measure\-touchpad\-pressure \- measure pressure properties of devices
+.SH SYNOPSIS
+.B libinput measure touchpad\-pressure [\-\-help] [options]
+[\fI/dev/input/event0\fI]
+.SH DESCRIPTION
+.PP
+The
+.B "libinput measure touchpad\-pressure"
+tool measures the pressure of touches on a touchpad. This is
+an interactive tool. When executed, the tool will prompt the user to
+interact with the touchpad. On termination, the tool prints a summary of the
+pressure values seen. This data should be attached to any
+pressure\-related bug report.
+.PP
+For a full description on how libinput's pressure-to-click behavior works, see
+the online documentation here:
+.I https://wayland.freedesktop.org/libinput/doc/latest/touchpad_pressure.html
+and
+.I https://wayland.freedesktop.org/libinput/doc/latest/palm_detection.html
+.PP
+This is a debugging tool only, its output may change at any time. Do not
+rely on the output.
+.PP
+This tool usually needs to be run as root to have access to the
+/dev/input/eventX nodes.
+.SH OPTIONS
+If a device node is given, this tool opens that device node. Otherwise, this
+tool searches for the first node that looks like a touchpad and uses that
+node.
+.TP 8
+.B \-\-help
+Print help
+.TP 8
+.B \-\-touch\-thresholds=\fI"down:up"\fR
+Set the logical touch pressure thresholds to
+.I down
+and
+.I up,
+respectively. When a touch exceeds the pressure in
+.I down
+it is considered logically down. If a touch is logically down and goes below
+the pressure in
+.I up,
+it is considered logically up. The thresholds have to be in
+device-specific pressure values and it is required that
+.I down
+>=
+.I up.
+.TP 8
+.B \-\-palm\-threshold=\fIN\fR
+Assume a palm threshold of
+.I N.
+The threshold has to be in device-specific pressure values.
+.PP
+If the touch-thresholds or the palm-threshold are not provided,
+this tool uses the thresholds provided by the udev hwdb (if any) or the
+built-in defaults.
+.SH LIBINPUT
+Part of the
+.B libinput(1)
+suite
diff --git a/tools/libinput-measure.man b/tools/libinput-measure.man
index 470657fe..f73bf4fe 100644
--- a/tools/libinput-measure.man
+++ b/tools/libinput-measure.man
@@ -24,6 +24,9 @@ Features that can be measured include
.TP 8
.B libinput\-measure\-touchpad\-tap\-time(1)
Measure tap-to-click time.
+.TP 8
+.B libinput\-measure\-touchpad\-pressure(1)
+Measure touch pressure.
.SH LIBINPUT
Part of the
.B libinput(1)
diff --git a/tools/libinput.man b/tools/libinput.man
index 39bb34c4..8bc8ced0 100644
--- a/tools/libinput.man
+++ b/tools/libinput.man
@@ -50,6 +50,9 @@ Measure various properties of devices.
.TP 8
.B libinput\-measure\-touchpad\-tap(1)
Measure tap-to-click time.
+.TP 8
+.B libinput\-measure\-touchpad\-pressure(1)
+Measure touch pressure.
.SH LIBINPUT
Part of the
.B libinput(1)
--
2.13.0
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