[PATCH 5/7] evdev: Normalize orientation and pressure values

[Andreas Pokorny]

Pressure values will be mapped into the range [0;1] while orientation
will be mapped to [-1;1] (or ]-1;1] or [0;1] depending on the how the
underlying device configures the axis value ranges).
---
 src/evdev.c    |  6 ++++++
 src/evdev.h    |  1 +
 src/libinput.c | 14 ++++++++++++--
 src/libinput.h | 11 ++++++-----
 test/touch.c   |  8 ++++----
 5 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/src/evdev.c b/src/evdev.c
index 6f68554..f75e1c3 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -1906,6 +1906,12 @@ evdev_configure_device(struct evdev_device *device)
 			return -1;
 		}
 	}
+	if (libevdev_has_event_code(evdev, EV_ABS, ABS_MT_ORIENTATION)) {
+		device->abs.absinfo_orientation = libevdev_get_abs_info(evdev, ABS_MT_ORIENTATION);
+	}
+	if (libevdev_has_event_code(evdev, EV_ABS, ABS_MT_PRESSURE)) {
+		device->abs.absinfo_pressure = libevdev_get_abs_info(evdev, ABS_MT_PRESSURE);
+	}
 
 	if (udev_tags & EVDEV_UDEV_TAG_TOUCHPAD) {
 		device->dispatch = evdev_mt_touchpad_create(device);
diff --git a/src/evdev.h b/src/evdev.h
index 8e67e5d..c7d762b 100644
--- a/src/evdev.h
+++ b/src/evdev.h
@@ -128,6 +128,7 @@ struct evdev_device {
 	int fd;
 	struct {
 		const struct input_absinfo *absinfo_x, *absinfo_y;
+		const struct input_absinfo *absinfo_pressure, *absinfo_orientation;
 		int fake_resolution;
 
 		struct device_coords point;
diff --git a/src/libinput.c b/src/libinput.c
index 92cc790..9357c01 100644
--- a/src/libinput.c
+++ b/src/libinput.c
@@ -667,25 +667,35 @@ libinput_event_touch_get_touch_minor(struct libinput_event_touch *event)
 LIBINPUT_EXPORT double
 libinput_event_touch_get_orientation(struct libinput_event_touch *event)
 {
+	struct evdev_device *device =
+		(struct evdev_device *) event->base.device;
+
 	require_event_type(libinput_event_get_context(&event->base),
 			   event->base.type,
 			   0,
 			   LIBINPUT_EVENT_TOUCH_DOWN,
 			   LIBINPUT_EVENT_TOUCH_MOTION);
 
-	return event->orientation;
+	if (device->abs.absinfo_orientation->minimum < 0)
+		return evdev_scale_axis(device->abs.absinfo_orientation, event->orientation, 2.0) - 1.0;
+	else /* this branch assume a simplisitic orientation calculation which either only yields 0 or 1
+		or only values within the positive quadrant between y and x axis */
+		return evdev_scale_axis(device->abs.absinfo_orientation, event->orientation, 1.0);
 }
 
 LIBINPUT_EXPORT double
 libinput_event_touch_get_pressure(struct libinput_event_touch *event)
 {
+	struct evdev_device *device =
+		(struct evdev_device *) event->base.device;
+
 	require_event_type(libinput_event_get_context(&event->base),
 			   event->base.type,
 			   0,
 			   LIBINPUT_EVENT_TOUCH_DOWN,
 			   LIBINPUT_EVENT_TOUCH_MOTION);
 
-	return event->pressure;
+	return evdev_scale_axis(device->abs.absinfo_pressure, event->pressure, 1.0);
 }
 
 struct libinput_source *
diff --git a/src/libinput.h b/src/libinput.h
index deecdda..f6f51b5 100644
--- a/src/libinput.h
+++ b/src/libinput.h
@@ -950,8 +950,8 @@ libinput_event_touch_get_touch_major(struct libinput_event_touch *event);
 /**
  * @ingroup event_touch
  *
- * Return the current pressure value touch point as a device specific value.
- * This value might not be measured by the device.
+ * Return the current pressure value touch point normalized to the range
+ * [0;1]. This value might not be measured by the device.
  *
  * For events not of type @ref LIBINPUT_EVENT_TOUCH_DOWN, @ref
  * LIBINPUT_EVENT_TOUCH_MOTION, this function returns 0.
@@ -968,9 +968,10 @@ libinput_event_touch_get_pressure(struct libinput_event_touch *event);
 /**
  * @ingroup event_touch
  *
- * Return the orientation of the touch ellipse in device specific values.
- * If the ellipse is aligned with the Y Axis of the screen 0 should be
- * returned.
+ * Return the revolution of the touch ellipse against the Y axis within the
+ * range [-1;1]. The value 0 will be returned when the ellipse is aligned
+ * with the Y Axis. If the ellipse is aligned with X Axis 1 will be returned.
+ * This value might not be measured by the device.
  *
  * For events not of type @ref LIBINPUT_EVENT_TOUCH_DOWN, @ref
  * LIBINPUT_EVENT_TOUCH_MOTION, this function returns 0.
diff --git a/test/touch.c b/test/touch.c
index 7a69bd7..10c4e2d 100644
--- a/test/touch.c
+++ b/test/touch.c
@@ -674,8 +674,8 @@ START_TEST(touch_point_properties)
 	tev = libinput_event_get_touch_event(ev);
 
 	ck_assert_int_eq(libinput_event_touch_get_slot(tev), 0);
-	ck_assert_int_eq(libinput_event_touch_get_pressure(tev), 128);
-	ck_assert_int_eq(libinput_event_touch_get_orientation(tev), 64);
+	litest_assert_double_eq(libinput_event_touch_get_pressure(tev), 0.5);
+	litest_assert_double_eq(libinput_event_touch_get_orientation(tev), 0.25);
 	ck_assert_int_eq(libinput_event_touch_get_touch_major(tev), 14);
 	ck_assert_int_eq(libinput_event_touch_get_touch_minor(tev), 8);
 
@@ -691,8 +691,8 @@ START_TEST(touch_point_properties)
 	ev = libinput_get_event(li);
 	tev = libinput_event_get_touch_event(ev);
 
-	ck_assert_int_eq(libinput_event_touch_get_pressure(tev), 128);
-	ck_assert_int_eq(libinput_event_touch_get_orientation(tev), 128);
+	litest_assert_double_eq(libinput_event_touch_get_pressure(tev), 0.5);
+	litest_assert_double_eq(libinput_event_touch_get_orientation(tev), 0.5);
 	ck_assert_int_eq(libinput_event_touch_get_touch_major(tev), 30);
 	ck_assert_int_eq(libinput_event_touch_get_touch_minor(tev), 8);
 
-- 
2.1.4