[PATCH wayland v2] protocol: Clarify pointer axis event

[Jonas Ådahl]

Pointer axis events are in the same coordinate space as motion events.

Signed-off-by: Jonas Ådahl <jadahl at gmail.com>
---
 protocol/wayland.xml |   15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/protocol/wayland.xml b/protocol/wayland.xml
index 5e56cb8..31243a5 100644
--- a/protocol/wayland.xml
+++ b/protocol/wayland.xml
@@ -864,6 +864,21 @@
     <event name="axis">
       <description summary="axis event">
 	Scroll and other axis notifications.
+
+	For scroll events (vertical and horizontal scroll axes), the
+	value parameter is the length of a vector along the specified
+	axis in a coordinate space identical to those of motion events,
+	representing a relative movement along the specified axis.
+
+	For devices that support movements non-parallel to axes multiple
+	axis events will be emitted.
+
+	When applicable, for example for touch pads, the server can
+	choose to emit scroll events where the motion vector is
+	equivalent to a motion event vector.
+
+	When applicable, clients can transform its view relative to the
+	scroll distance.
       </description>
 
       <arg name="time" type="uint"/>
-- 
1.7.9.5