monitor: Move logical to CRTC transform helper to MetaOutput

So that it can be used on a per output basis in the future.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/1042

src/backends/meta-monitor.c

@@ -455,14 +455,8 @@ meta_monitor_logical_to_crtc_transform (MetaMonitor          *monitor,
                                         MetaMonitorTransform  transform)
 {
   MetaOutput *output = meta_monitor_get_main_output (monitor);
-  MetaMonitorTransform new_transform;
 
-  new_transform = (transform + output->panel_orientation_transform) %
-                  META_MONITOR_TRANSFORM_FLIPPED;
-  if (meta_monitor_transform_is_flipped (transform))
-    new_transform += META_MONITOR_TRANSFORM_FLIPPED;
-
-  return new_transform;
+  return meta_output_logical_to_crtc_transform (output, transform);
 }
 
 MetaMonitorTransform

src/backends/meta-output.c

@@ -62,6 +62,20 @@ meta_output_get_assigned_crtc (MetaOutput *output)
   return priv->crtc;
 }
 
+MetaMonitorTransform
+meta_output_logical_to_crtc_transform (MetaOutput           *output,
+                                       MetaMonitorTransform  transform)
+{
+  MetaMonitorTransform new_transform;
+
+  new_transform = (transform + output->panel_orientation_transform) %
+                  META_MONITOR_TRANSFORM_FLIPPED;
+  if (meta_monitor_transform_is_flipped (transform))
+    new_transform += META_MONITOR_TRANSFORM_FLIPPED;
+
+  return new_transform;
+}
+
 static void
 meta_output_dispose (GObject *object)
 {

src/backends/meta-output.h

@@ -129,6 +129,9 @@ void meta_output_assign_crtc (MetaOutput *output,
 META_EXPORT_TEST
 void meta_output_unassign_crtc (MetaOutput *output);
 
+MetaMonitorTransform meta_output_logical_to_crtc_transform (MetaOutput           *output,
+                                                            MetaMonitorTransform  transform);
+
 META_EXPORT_TEST
 MetaCrtc * meta_output_get_assigned_crtc (MetaOutput *output);