backends/native: Add PLANE_PROP_HOTSPOT_[X,Y]

Add META_KMS_PLANE_PROP_HOTSPOT_[X,Y] properties
to the MetaKmsPlaneProp enumeration, and
properly initialise them.

Also, add a convenience method in meta-kms-plane
(i.e., `meta_kms_plane_supports_cursor_hotspot`)
to check whether a plane supports hotspot
property setting.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3337>

src/backends/native/meta-kms-cursor-manager.c

@@ -405,6 +405,8 @@ maybe_update_cursor_plane (MetaKmsCursorManagerImpl  *cursor_manager_impl,
         .height = round (cursor_rect.size.height),
       };
 
+      if (meta_kms_plane_supports_cursor_hotspot (cursor_plane))
+        {
           plane_assignment = meta_kms_update_assign_plane (update,
                                                            crtc, cursor_plane,
                                                            buffer,
@@ -414,6 +416,7 @@ maybe_update_cursor_plane (MetaKmsCursorManagerImpl  *cursor_manager_impl,
                                                         (int) roundf (hotspot->x),
                                                         (int) roundf (hotspot->y));
         }
+    }
   else
     {
       *old_buffer = g_steal_pointer (&crtc_state_impl->pending_buffer);

src/backends/native/meta-kms-plane-private.h

@@ -40,6 +40,8 @@ typedef enum _MetaKmsPlaneProp
   META_KMS_PLANE_PROP_CRTC_ID,
   META_KMS_PLANE_PROP_FB_DAMAGE_CLIPS_ID,
   META_KMS_PLANE_PROP_IN_FENCE_FD,
+  META_KMS_PLANE_PROP_HOTSPOT_X,
+  META_KMS_PLANE_PROP_HOTSPOT_Y,
   META_KMS_PLANE_N_PROPS
 } MetaKmsPlaneProp;
 

src/backends/native/meta-kms-plane.c

@@ -26,6 +26,8 @@
 #include "backends/meta-monitor-transform.h"
 #include "backends/native/meta-kms-crtc.h"
 #include "backends/native/meta-kms-impl-device.h"
+#include "backends/native/meta-kms-impl-device-atomic.h"
+#include "backends/native/meta-kms-device-private.h"
 #include "backends/native/meta-kms-update-private.h"
 
 typedef struct _MetaKmsPlanePropTable
@@ -189,6 +191,23 @@ meta_kms_plane_is_transform_handled (MetaKmsPlane         *plane,
   return FALSE;
 }
 
+gboolean
+meta_kms_plane_supports_cursor_hotspot (MetaKmsPlane *plane)
+{
+  MetaKmsImplDevice *impl_device =
+    meta_kms_device_get_impl_device (plane->device);
+
+  if (META_IS_KMS_IMPL_DEVICE_ATOMIC (impl_device))
+    {
+      return (meta_kms_plane_get_prop_id (plane, META_KMS_PLANE_PROP_HOTSPOT_X) &&
+              meta_kms_plane_get_prop_id (plane, META_KMS_PLANE_PROP_HOTSPOT_Y));
+    }
+  else
+    {
+      return TRUE;
+    }
+}
+
 GArray *
 meta_kms_plane_get_modifiers_for_format (MetaKmsPlane *plane,
                                          uint32_t      format)
@@ -505,6 +524,16 @@ init_properties (MetaKmsPlane            *plane,
           .name = "IN_FENCE_FD",
           .type = DRM_MODE_PROP_SIGNED_RANGE,
         },
+      [META_KMS_PLANE_PROP_HOTSPOT_X] =
+        {
+          .name = "HOTSPOT_X",
+          .type = DRM_MODE_PROP_SIGNED_RANGE,
+        },
+      [META_KMS_PLANE_PROP_HOTSPOT_Y] =
+        {
+          .name = "HOTSPOT_Y",
+          .type = DRM_MODE_PROP_SIGNED_RANGE,
+        },
     },
     .rotation_bitmask = {
       [META_KMS_PLANE_ROTATION_BIT_ROTATE_0] =

src/backends/native/meta-kms-plane.h

@@ -47,6 +47,8 @@ MetaKmsPlaneType meta_kms_plane_get_plane_type (MetaKmsPlane *plane);
 gboolean meta_kms_plane_is_transform_handled (MetaKmsPlane         *plane,
                                               MetaMonitorTransform  transform);
 
+gboolean meta_kms_plane_supports_cursor_hotspot (MetaKmsPlane *plane);
+
 GArray * meta_kms_plane_get_modifiers_for_format (MetaKmsPlane *plane,
                                                   uint32_t      format);