[RFC Wayland 2/2] protocol: change input and opaque region interface

[Pekka Paalanen]

This change breaks the protocol.

Now that set_input_region and set_opaque_region no longer have to
describe the region atomically in one request, we can simplify the
protocol by not using wl_region for them.

Instead, the new requests mark_input and mark_opaque will take a
simple rectangle, like damage already does. For describing complex forms
clients will just send one rectangle at a time, and the server will
accumulate the union of them. The wl_surface.commit request takes care,
that no partial data is used.

Since the action is now union instead of replace, a way to clear the
regions is needed. This is provided by the implicit clear on the first
mark_* request after a wl_surface.commit.

As nothing uses wl_region interface anymore, it is removed from the
core.

Signed-off-by: Pekka Paalanen <ppaalanen at gmail.com>
---
 protocol/wayland.xml |   98 +++++++++++++++++--------------------------------
 1 files changed, 34 insertions(+), 64 deletions(-)

diff --git a/protocol/wayland.xml b/protocol/wayland.xml
index 8b34084..81f4812 100644
--- a/protocol/wayland.xml
+++ b/protocol/wayland.xml
@@ -126,13 +126,6 @@
       </description>
       <arg name="id" type="new_id" interface="wl_surface"/>
     </request>
-
-    <request name="create_region">
-      <description summary="create new region">
-	Ask the compositor to create a new region.
-      </description>
-      <arg name="id" type="new_id" interface="wl_region"/>
-    </request>
   </interface>
 
   <interface name="wl_shm_pool" version="1">
@@ -704,9 +697,9 @@
       <arg name="callback" type="new_id" interface="wl_callback"/>
     </request>
 
-    <request name="set_opaque_region">
-      <description summary="set opaque region">
-	This request sets the region of the surface that contains
+    <request name="mark_opaque">
+      <description summary="change opaque region for surface">
+	This request is used to describe the regions of the surface that have
 	opaque content.  The opaque region is an optimization hint for
 	the compositor that lets it optimize out redrawing of content
 	behind opaque regions.  Setting an opaque region is not
@@ -717,40 +710,52 @@
 
 	Opaque region is double-buffered state, see wl_surface.commit.
 
-	wl_surface.set_opaque_region changes the pending opaque region.
-	wl_surface.commit copies the pending region to the current region.
+	wl_surface.commit copies the pending opaque region to the current region.
+	The first wl_surface.mark_opaque request after a wl_surface.commit will
+	clear the pending opaque region before adding the given rectangle.
+	Further wl_surface.mark_opaque requests just add the given rectangle to
+	the pending opaque region, until the next wl_surface.commit.
 	Otherwise the pending and current regions are never changed.
 
-	The initial value for opaque region is empty. Setting the pending
-	opaque region has copy semantics, and the wl_region object can be
-	destroyed immediately. A nil wl_region causes the pending opaque
-	region to be set to empty.
+	The initial value for opaque region is empty. The pending opaque
+	region can be set to empty by sending the first mark_opaque request
+	after a wl_surface.commit with a zero width and/or height.
       </description>
 
-      <arg name="region" type="object" interface="wl_region" allow-null="true"/>
+      <arg name="x" type="int"/>
+      <arg name="y" type="int"/>
+      <arg name="width" type="int"/>
+      <arg name="height" type="int"/>
     </request>
 
-    <request name="set_input_region">
-      <description summary="set input region">
-	This request sets the region of the surface that can receive
-	pointer and touch events. Input events happening outside of
-	this region will try the next surface in the server surface
-	stack. The compositor ignores the parts of the input region that
+    <request name="mark_input">
+      <description summary="change input sensitive region for surface">
+	This request is used to describe the regions of the surface that can
+	receive pointer and touch events. Input events initiating at
+	coordinates outside of this region will ignore this surface, and
+	input device enter/leave events obey the input region rather than the
+	surface. The compositor ignores the parts of the input region that
 	fall outside of the surface.
 
 	Input region is double-buffered state, see wl_surface.commit.
 
-	wl_surface.set_input_region changes the pending input region.
-	wl_surface.commit copies the pending region to the current region.
+	wl_surface.commit copies the pending input region to the current region.
+	The first wl_surface.mark_input request after a wl_surface.commit will
+	clear the pending input region before adding the given rectangle.
+	Further wl_surface.mark_input requests just add the given rectangle to
+	the pending input region, until the next wl_surface.commit.
 	Otherwise the pending and current regions are never changed.
 
 	The initial value for input region is infinite. That means the whole
-	surface will accept input. Setting the pending input region has copy
-	semantics, and the wl_region object can be destroyed immediately. A
-	nil wl_region causes the input region to be set to infinite.
+	surface will accept input. The pending input region can be set to
+	empty by sending the first mark_input request after a
+	wl_surface.commit with a zero width and/or height.
       </description>
 
-      <arg name="region" type="object" interface="wl_region" allow-null="true"/>
+      <arg name="x" type="int"/>
+      <arg name="y" type="int"/>
+      <arg name="width" type="int"/>
+      <arg name="height" type="int"/>
     </request>
 
     <request name="commit">
@@ -1143,39 +1148,4 @@
     </event>
   </interface>
 
-  <interface name="wl_region" version="1">
-    <description summary="region interface">
-      Region.
-    </description>
-
-    <request name="destroy" type="destructor">
-      <description summary="destroy region">
-	Destroy the region.  This will invalidate the object id.
-      </description>
-    </request>
-
-    <request name="add">
-      <description summary="add rectangle to region">
-	Add the specified rectangle to the region
-      </description>
-
-      <arg name="x" type="int"/>
-      <arg name="y" type="int"/>
-      <arg name="width" type="int"/>
-      <arg name="height" type="int"/>
-    </request>
-
-    <request name="subtract">
-      <description summary="subtract rectangle from region">
-	Subtract the specified rectangle from the region
-      </description>
-
-      <arg name="x" type="int"/>
-      <arg name="y" type="int"/>
-      <arg name="width" type="int"/>
-      <arg name="height" type="int"/>
-    </request>
-
-  </interface>
-
 </protocol>
-- 
1.7.8.6