[mutter] MetaWaylandPointerConstraint: Fix effective region calculation

[Jonas Ådahl <jadahl src gnome org>]

commit 62ac9df43d11b166f991f24a58b7a95d4dfdac03
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue Feb 23 21:26:52 2016 +0800

    MetaWaylandPointerConstraint: Fix effective region calculation
    
    The when surface->input_region is NULL, it should be interpreted as the
    whole surface region. If not, the effective input region is the
    intersection of the buffer region and the input region set by
    wl_surface.set_input_region. Add
    meta_wayland_surface_calculate_input_region() that does this
    calculation.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=762661

 src/wayland/meta-wayland-pointer-constraints.c |    4 ++--
 src/wayland/meta-wayland-surface.c             |   23 +++++++++++++++++++++++
 src/wayland/meta-wayland-surface.h             |    2 ++
 3 files changed, 27 insertions(+), 2 deletions(-)
---
diff --git a/src/wayland/meta-wayland-pointer-constraints.c b/src/wayland/meta-wayland-pointer-constraints.c
index 5dc0476..e5b0f2c 100644
--- a/src/wayland/meta-wayland-pointer-constraints.c
+++ b/src/wayland/meta-wayland-pointer-constraints.c
@@ -237,7 +237,7 @@ is_within_constraint_region (MetaWaylandPointerConstraint *constraint,
   gboolean is_within;
 
   region = meta_wayland_pointer_constraint_calculate_effective_region (constraint);
-  is_within = cairo_region_contains_point (constraint->region,
+  is_within = cairo_region_contains_point (region,
                                            wl_fixed_to_int (sx),
                                            wl_fixed_to_int (sy));
   cairo_region_destroy (region);
@@ -330,7 +330,7 @@ meta_wayland_pointer_constraint_calculate_effective_region (MetaWaylandPointerCo
 {
   cairo_region_t *region;
 
-  region = cairo_region_copy (constraint->surface->input_region);
+  region = meta_wayland_surface_calculate_input_region (constraint->surface);
   cairo_region_intersect (region, constraint->region);
 
   return region;
diff --git a/src/wayland/meta-wayland-surface.c b/src/wayland/meta-wayland-surface.c
index f3621a9..78c4735 100644
--- a/src/wayland/meta-wayland-surface.c
+++ b/src/wayland/meta-wayland-surface.c
@@ -2754,3 +2754,26 @@ meta_wayland_surface_role_subsurface_class_init (MetaWaylandSurfaceRoleSubsurfac
   surface_role_class->commit = subsurface_surface_commit;
   surface_role_class->is_on_output = actor_surface_is_on_output;
 }
+
+cairo_region_t *
+meta_wayland_surface_calculate_input_region (MetaWaylandSurface *surface)
+{
+  cairo_region_t *region;
+  cairo_rectangle_int_t buffer_rect;
+  CoglTexture *texture;
+
+  if (!surface->buffer)
+    return NULL;
+
+  texture = surface->buffer->texture;
+  buffer_rect = (cairo_rectangle_int_t) {
+    .width = cogl_texture_get_width (texture) / surface->scale,
+    .height = cogl_texture_get_height (texture) / surface->scale,
+  };
+  region = cairo_region_create_rectangle (&buffer_rect);
+
+  if (surface->input_region)
+    cairo_region_intersect (region, surface->input_region);
+
+  return region;
+}
diff --git a/src/wayland/meta-wayland-surface.h b/src/wayland/meta-wayland-surface.h
index a153176..bc10276 100644
--- a/src/wayland/meta-wayland-surface.h
+++ b/src/wayland/meta-wayland-surface.h
@@ -287,4 +287,6 @@ void                meta_wayland_surface_get_absolute_coordinates (MetaWaylandSu
 
 MetaWaylandSurface * meta_wayland_surface_role_get_surface (MetaWaylandSurfaceRole *role);
 
+cairo_region_t *    meta_wayland_surface_calculate_input_region (MetaWaylandSurface *surface);
+
 #endif