monitor-manager: Expose whether the backend handles a transform

Expose via a new API whether the transform on a logical monitor is
handled by the backend. This was previously only exposed only in the
native backend. This will be used to emulate not supporting transforms
in the backend in the nested backend.

https://bugzilla.gnome.org/show_bug.cgi?id=779745

src/backends/meta-monitor-manager-dummy.c

@@ -521,6 +521,14 @@ meta_monitor_manager_dummy_apply_config (MetaMonitorManager *manager,
   meta_monitor_manager_rebuild_derived (manager);
 }
 
+static gboolean
+meta_monitor_manager_dummy_is_transform_handled (MetaMonitorManager  *manager,
+                                                 MetaCrtc            *crtc,
+                                                 MetaMonitorTransform transform)
+{
+  return TRUE;
+}
+
 static void
 meta_monitor_manager_dummy_class_init (MetaMonitorManagerDummyClass *klass)
 {
@@ -530,6 +538,7 @@ meta_monitor_manager_dummy_class_init (MetaMonitorManagerDummyClass *klass)
   manager_class->ensure_initial_config = meta_monitor_manager_dummy_ensure_initial_config;
   manager_class->apply_monitors_config = meta_monitor_manager_dummy_apply_monitors_config;
   manager_class->apply_configuration = meta_monitor_manager_dummy_apply_config;
+  manager_class->is_transform_handled = meta_monitor_manager_dummy_is_transform_handled;
 }
 
 static void

src/backends/meta-monitor-manager-private.h

@@ -345,6 +345,9 @@ struct _MetaMonitorManagerClass
   void (*tiled_monitor_removed) (MetaMonitorManager *,
                                  MetaMonitor        *);
 
+  gboolean (*is_transform_handled) (MetaMonitorManager  *,
+                                    MetaCrtc            *,
+                                    MetaMonitorTransform);
 };
 
 void                meta_monitor_manager_rebuild (MetaMonitorManager *manager,
@@ -428,6 +431,10 @@ void               meta_monitor_manager_tiled_monitor_added (MetaMonitorManager
 void               meta_monitor_manager_tiled_monitor_removed (MetaMonitorManager *manager,
                                                                MetaMonitor        *monitor);
 
+gboolean           meta_monitor_manager_is_transform_handled (MetaMonitorManager  *manager,
+                                                              MetaCrtc            *crtc,
+                                                              MetaMonitorTransform transform);
+
 MetaMonitorsConfig * meta_monitor_manager_ensure_configured (MetaMonitorManager *manager);
 
 void               meta_monitor_manager_update_logical_state (MetaMonitorManager *manager,

src/backends/meta-monitor-manager.c

@@ -1725,6 +1725,17 @@ meta_monitor_manager_tiled_monitor_removed (MetaMonitorManager *manager,
     manager_class->tiled_monitor_removed (manager, monitor);
 }
 
+gboolean
+meta_monitor_manager_is_transform_handled (MetaMonitorManager  *manager,
+                                           MetaCrtc            *crtc,
+                                           MetaMonitorTransform transform)
+{
+  MetaMonitorManagerClass *manager_class =
+    META_MONITOR_MANAGER_GET_CLASS (manager);
+
+  return manager_class->is_transform_handled (manager, crtc, transform);
+}
+
 void
 meta_monitor_manager_read_current_state (MetaMonitorManager *manager)
 {

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

@@ -1968,6 +1968,19 @@ meta_monitor_manager_kms_wait_for_flip (MetaMonitorManagerKms *manager_kms)
   drmHandleEvent (manager_kms->fd, &evctx);
 }
 
+static gboolean
+meta_monitor_manager_kms_is_transform_handled (MetaMonitorManager  *manager,
+                                               MetaCrtc            *crtc,
+                                               MetaMonitorTransform transform)
+{
+  MetaCrtcKms *crtc_kms = crtc->driver_private;
+
+  if ((1 << crtc->transform) & crtc_kms->all_hw_transforms)
+    return TRUE;
+  else
+    return FALSE;
+}
+
 static void
 meta_monitor_manager_kms_dispose (GObject *object)
 {
@@ -2007,20 +2020,5 @@ meta_monitor_manager_kms_class_init (MetaMonitorManagerKmsClass *klass)
   manager_class->set_power_save_mode = meta_monitor_manager_kms_set_power_save_mode;
   manager_class->get_crtc_gamma = meta_monitor_manager_kms_get_crtc_gamma;
   manager_class->set_crtc_gamma = meta_monitor_manager_kms_set_crtc_gamma;
-}
+  manager_class->is_transform_handled = meta_monitor_manager_kms_is_transform_handled;
-
-MetaMonitorTransform
-meta_monitor_manager_kms_get_view_transform (MetaMonitorManagerKms *manager,
-                                             MetaCrtc              *crtc)
-{
-  MetaCrtcKms *crtc_kms;
-
-  crtc_kms = crtc->driver_private;
-  if ((1 << crtc->transform) & crtc_kms->all_hw_transforms)
-    {
-      /* Transform is managed by the hardware, the view is untransformed */
-      return META_MONITOR_TRANSFORM_NORMAL;
-    }
-
-  return crtc->transform;
 }

src/backends/native/meta-monitor-manager-kms.h

@@ -58,9 +58,4 @@ gboolean meta_monitor_manager_kms_flip_crtc (MetaMonitorManagerKms *manager_kms,
 
 void meta_monitor_manager_kms_wait_for_flip (MetaMonitorManagerKms *manager_kms);
 
-MetaMonitorTransform
-meta_monitor_manager_kms_get_view_transform (MetaMonitorManagerKms *manager,
-                                             MetaCrtc              *crtc);
-
-
 #endif /* META_MONITOR_MANAGER_KMS_H */

src/backends/native/meta-renderer-native.c

@@ -1398,25 +1398,6 @@ meta_renderer_native_queue_modes_reset (MetaRendererNative *renderer_native)
     }
 }
 
-static MetaMonitorTransform
-meta_renderer_native_get_logical_monitor_transform (MetaRenderer       *renderer,
-                                                    MetaLogicalMonitor *logical_monitor)
-{
-  MetaBackend *backend = meta_get_backend ();
-  MetaMonitorManager *monitor_manager =
-    meta_backend_get_monitor_manager (backend);
-  MetaMonitorManagerKms *monitor_manager_kms =
-    META_MONITOR_MANAGER_KMS (monitor_manager);
-  MetaMonitor *monitor;
-  MetaOutput *output;
-
-  monitor = meta_logical_monitor_get_monitors (logical_monitor)->data;
-  output = meta_monitor_get_main_output (monitor);
-
-  return meta_monitor_manager_kms_get_view_transform (monitor_manager_kms,
-                                                      output->crtc);
-}
-
 static CoglOnscreen *
 meta_renderer_native_create_onscreen (MetaRendererNative    *renderer,
                                       CoglContext           *context,
@@ -1689,38 +1670,61 @@ meta_renderer_native_create_legacy_view (MetaRendererNative *renderer_native)
   return view;
 }
 
+static MetaMonitorTransform
+calculate_view_transform (MetaMonitorManager *monitor_manager,
+                          MetaLogicalMonitor *logical_monitor)
+{
+  MetaMonitor *main_monitor;
+  MetaOutput *main_output;
+  main_monitor = meta_logical_monitor_get_monitors (logical_monitor)->data;
+  main_output = meta_monitor_get_main_output (main_monitor);
+
+  /*
+   * Pick any monitor and output and check; all CRTCs of a logical monitor will
+   * always have the same transform assigned to them.
+   */
+
+  if (meta_monitor_manager_is_transform_handled (monitor_manager,
+                                                 main_output->crtc,
+                                                 main_output->crtc->transform))
+    return META_MONITOR_TRANSFORM_NORMAL;
+  else
+    return main_output->crtc->transform;
+}
+
 static MetaRendererView *
 meta_renderer_native_create_view (MetaRenderer       *renderer,
                                   MetaLogicalMonitor *logical_monitor)
 {
   MetaBackend *backend = meta_get_backend ();
+  MetaMonitorManager *monitor_manager =
+    meta_backend_get_monitor_manager (backend);
   ClutterBackend *clutter_backend = meta_backend_get_clutter_backend (backend);
   CoglContext *cogl_context = clutter_backend_get_cogl_context (clutter_backend);
   CoglDisplay *cogl_display = cogl_context_get_display (cogl_context);
   CoglDisplayEGL *egl_display = cogl_display->winsys;
   CoglOnscreenEGL *egl_onscreen;
-  MetaMonitorTransform transform;
+  MetaMonitorTransform view_transform;
   CoglOnscreen *onscreen = NULL;
   CoglOffscreen *offscreen = NULL;
   MetaRendererView *view;
   GError *error = NULL;
 
-  transform = meta_renderer_native_get_logical_monitor_transform (renderer,
+  view_transform = calculate_view_transform (monitor_manager, logical_monitor);
-                                                                  logical_monitor);
 
   onscreen = meta_renderer_native_create_onscreen (META_RENDERER_NATIVE (renderer),
                                                    cogl_context,
-                                                   transform,
+                                                   view_transform,
                                                    logical_monitor->rect.width,
                                                    logical_monitor->rect.height);
   if (!onscreen)
     meta_fatal ("Failed to allocate onscreen framebuffer\n");
 
-  if (transform != META_MONITOR_TRANSFORM_NORMAL)
+  if (view_transform != META_MONITOR_TRANSFORM_NORMAL)
     {
       offscreen = meta_renderer_native_create_offscreen (META_RENDERER_NATIVE (renderer),
                                                          cogl_context,
-                                                         transform,
+                                                         view_transform,
                                                          logical_monitor->rect.width,
                                                          logical_monitor->rect.height);
       if (!offscreen)
@@ -1732,7 +1736,7 @@ meta_renderer_native_create_view (MetaRenderer       *renderer,
                        "framebuffer", onscreen,
                        "offscreen", offscreen,
                        "logical-monitor", logical_monitor,
-                       "transform", transform,
+                       "transform", view_transform,
                        NULL);
   g_clear_pointer (&offscreen, cogl_object_unref);
 

src/backends/x11/meta-monitor-manager-xrandr.c

@@ -1558,6 +1558,16 @@ meta_monitor_manager_xrandr_init_monitors (MetaMonitorManagerXrandr *manager_xra
 }
 #endif
 
+static gboolean
+meta_monitor_manager_xrandr_is_transform_handled (MetaMonitorManager  *manager,
+                                                  MetaCrtc            *crtc,
+                                                  MetaMonitorTransform transform)
+{
+  g_warn_if_fail (crtc->all_transforms & transform);
+
+  return TRUE;
+}
+
 static void
 meta_monitor_manager_xrandr_init (MetaMonitorManagerXrandr *manager_xrandr)
 {
@@ -1633,6 +1643,7 @@ meta_monitor_manager_xrandr_class_init (MetaMonitorManagerXrandrClass *klass)
   manager_class->tiled_monitor_added = meta_monitor_manager_xrandr_tiled_monitor_added;
   manager_class->tiled_monitor_removed = meta_monitor_manager_xrandr_tiled_monitor_removed;
 #endif
+  manager_class->is_transform_handled = meta_monitor_manager_xrandr_is_transform_handled;
 
   quark_meta_monitor_xrandr_data =
     g_quark_from_static_string ("-meta-monitor-xrandr-data");

src/tests/meta-monitor-manager-test.c

@@ -327,6 +327,14 @@ meta_monitor_manager_test_tiled_monitor_removed (MetaMonitorManager *manager,
   manager_test->tiled_monitor_count--;
 }
 
+static gboolean
+meta_monitor_manager_test_is_transform_handled (MetaMonitorManager  *manager,
+                                                MetaCrtc            *crtc,
+                                                MetaMonitorTransform transform)
+{
+  return TRUE;
+}
+
 static void
 meta_monitor_manager_test_dispose (GObject *object)
 {
@@ -358,4 +366,5 @@ meta_monitor_manager_test_class_init (MetaMonitorManagerTestClass *klass)
   manager_class->apply_configuration = meta_monitor_manager_test_apply_configuration;
   manager_class->tiled_monitor_added = meta_monitor_manager_test_tiled_monitor_added;
   manager_class->tiled_monitor_removed = meta_monitor_manager_test_tiled_monitor_removed;
+  manager_class->is_transform_handled = meta_monitor_manager_test_is_transform_handled;
 }