[PATCH libinput 3/4] Change absolute and touch events to use mm as default unit

[Peter Hutterer]

Instead of device-specific coordinates that the caller can't interpret without
knowing the range anyway, return mm as the default value.

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/evdev.h         |  7 +++++++
 src/libinput.c      | 20 ++++++++++++++++----
 src/libinput.h      | 32 ++++++++++++--------------------
 tools/event-debug.c |  7 +++++--
 4 files changed, 40 insertions(+), 26 deletions(-)

diff --git a/src/evdev.h b/src/evdev.h
index 03b6742..eebfab1 100644
--- a/src/evdev.h
+++ b/src/evdev.h
@@ -164,4 +164,11 @@ evdev_device_remove(struct evdev_device *device);
 void
 evdev_device_destroy(struct evdev_device *device);
 
+static inline double
+evdev_convert_to_mm(const struct input_absinfo *absinfo, double v)
+{
+	double value = v - absinfo->minimum;
+	return value/absinfo->resolution;
+}
+
 #endif /* EVDEV_H */
diff --git a/src/libinput.c b/src/libinput.c
index 5b10a10..f384f43 100644
--- a/src/libinput.c
+++ b/src/libinput.c
@@ -319,13 +319,19 @@ libinput_event_pointer_get_dy(struct libinput_event_pointer *event)
 LIBINPUT_EXPORT double
 libinput_event_pointer_get_absolute_x(struct libinput_event_pointer *event)
 {
-	return event->x;
+	struct evdev_device *device =
+		(struct evdev_device *) event->base.device;
+
+	return evdev_convert_to_mm(device->abs.absinfo_x, event->x);
 }
 
 LIBINPUT_EXPORT double
 libinput_event_pointer_get_absolute_y(struct libinput_event_pointer *event)
 {
-	return event->y;
+	struct evdev_device *device =
+		(struct evdev_device *) event->base.device;
+
+	return evdev_convert_to_mm(device->abs.absinfo_y, event->y);
 }
 
 LIBINPUT_EXPORT double
@@ -402,7 +408,10 @@ libinput_event_touch_get_seat_slot(struct libinput_event_touch *event)
 LIBINPUT_EXPORT double
 libinput_event_touch_get_x(struct libinput_event_touch *event)
 {
-	return event->x;
+	struct evdev_device *device =
+		(struct evdev_device *) event->base.device;
+
+	return evdev_convert_to_mm(device->abs.absinfo_x, event->x);
 }
 
 LIBINPUT_EXPORT double
@@ -428,7 +437,10 @@ libinput_event_touch_get_y_transformed(struct libinput_event_touch *event,
 LIBINPUT_EXPORT double
 libinput_event_touch_get_y(struct libinput_event_touch *event)
 {
-	return event->y;
+	struct evdev_device *device =
+		(struct evdev_device *) event->base.device;
+
+	return evdev_convert_to_mm(device->abs.absinfo_y, event->y);
 }
 
 struct libinput_source *
diff --git a/src/libinput.h b/src/libinput.h
index 54c96e5..c19460b 100644
--- a/src/libinput.h
+++ b/src/libinput.h
@@ -452,11 +452,9 @@ libinput_event_pointer_get_dy(struct libinput_event_pointer *event);
 /**
  * @ingroup event_pointer
  *
- * Return the current absolute x coordinate of the pointer event.
- *
- * The coordinate is in a device specific coordinate space; to get the
- * corresponding output screen coordinate, use
- * libinput_event_pointer_get_x_transformed().
+ * Return the current absolute x coordinate of the pointer event, in mm from
+ * the top left corner of the device. To get the corresponding output screen
+ * coordinate, use libinput_event_pointer_get_x_transformed().
  *
  * For pointer events that are not of type
  * LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE, this function returns 0.
@@ -472,11 +470,9 @@ libinput_event_pointer_get_absolute_x(struct libinput_event_pointer *event);
 /**
  * @ingroup event_pointer
  *
- * Return the current absolute y coordinate of the pointer event.
- *
- * The coordinate is in a device specific coordinate space; to get the
- * corresponding output screen coordinate, use
- * libinput_event_pointer_get_y_transformed().
+ * Return the current absolute y coordinate of the pointer event, in mm from
+ * the top left corner of the device. To get the corresponding output screen
+ * coordinate, use libinput_event_pointer_get_x_transformed().
  *
  * For pointer events that are not of type
  * LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE, this function returns 0.
@@ -677,11 +673,9 @@ libinput_event_touch_get_seat_slot(struct libinput_event_touch *event);
 /**
  * @ingroup event_touch
  *
- * Return the current absolute x coordinate of the touch event.
- *
- * The coordinate is in a device specific coordinate space; to get the
- * corresponding output screen coordinate, use
- * libinput_event_touch_get_x_transformed().
+ * Return the current absolute x coordinate of the touch event, in mm from
+ * the top left corner of the device. To get the corresponding output screen
+ * coordinate, use libinput_event_touch_get_x_transformed().
  *
  * @note this function should only be called for LIBINPUT_EVENT_TOUCH_DOWN and
  * LIBINPUT_EVENT_TOUCH_MOTION.
@@ -695,11 +689,9 @@ libinput_event_touch_get_x(struct libinput_event_touch *event);
 /**
  * @ingroup event_touch
  *
- * Return the current absolute y coordinate of the touch event.
- *
- * The coordinate is in a device specific coordinate space; to get the
- * corresponding output screen coordinate, use
- * libinput_event_touch_get_y_transformed().
+ * Return the current absolute y coordinate of the touch event, in mm from
+ * the top left corner of the device. To get the corresponding output screen
+ * coordinate, use libinput_event_touch_get_y_transformed().
  *
  * For LIBINPUT_EVENT_TOUCH_UP 0 is returned.
  *
diff --git a/tools/event-debug.c b/tools/event-debug.c
index 864f77e..ffb4524 100644
--- a/tools/event-debug.c
+++ b/tools/event-debug.c
@@ -329,13 +329,16 @@ print_touch_event_with_coords(struct libinput_event *ev)
 	struct libinput_event_touch *t = libinput_event_get_touch_event(ev);
 	double x = libinput_event_touch_get_x_transformed(t, screen_width);
 	double y = libinput_event_touch_get_y_transformed(t, screen_height);
+	double xmm = libinput_event_touch_get_x(t);
+	double ymm = libinput_event_touch_get_y(t);
 
 	print_event_time(libinput_event_touch_get_time(t));
 
-	printf("%d (%d) %5.2f/%5.2f\n",
+	printf("%d (%d) %5.2f/%5.2f (%5.2f/%5.2fmm)\n",
 	       libinput_event_touch_get_slot(t),
 	       libinput_event_touch_get_seat_slot(t),
-	       x, y);
+	       x, y,
+	       xmm, ymm);
 }
 
 static int
-- 
1.9.3