Gridmap editor now lists plane instead of floor when not horizontal.

Instead of gridmap editor calling grid as floor irrespective of the
orientation, it now calls the grid plane if it's vertical and floor
if horizontal.

Resolves: #14611

modules/gridmap/grid_map_editor_plugin.cpp

@@ -99,6 +99,20 @@ void GridMapEditor::_menu_option(int p_option) {
 				int idx = options->get_popup()->get_item_index(MENU_OPTION_X_AXIS + i);
 				options->get_popup()->set_item_checked(idx, i == new_axis);
 			}
+
+			if (edit_axis != new_axis) {
+				int item1 = options->get_popup()->get_item_id(MENU_OPTION_NEXT_LEVEL);
+				int item2 = options->get_popup()->get_item_id(MENU_OPTION_PREV_LEVEL);
+				if (edit_axis == Vector3::AXIS_Y) {
+					options->get_popup()->set_item_text(item1, TTR("Next Plane"));
+					options->get_popup()->set_item_text(item2, TTR("Previous Plane"));
+					spin_box_label->set_text(TTR("Plane:"));
+				} else if (new_axis == Vector3::AXIS_Y) {
+					options->get_popup()->set_item_text(item1, TTR("Next Floor"));
+					options->get_popup()->set_item_text(item2, TTR("Previous Floor"));
+					spin_box_label->set_text(TTR("Floor:"));
+				}
+			}
 			edit_axis = Vector3::Axis(new_axis);
 			update_grid();
 			_update_clip();
@@ -998,9 +1012,9 @@ GridMapEditor::GridMapEditor(EditorNode *p_editor) {
 	spatial_editor_hb->set_alignment(BoxContainer::ALIGN_END);
 	SpatialEditor::get_singleton()->add_control_to_menu_panel(spatial_editor_hb);
 
-	Label *fl = memnew(Label);
-	fl->set_text(TTR("Floor:"));
-	spatial_editor_hb->add_child(fl);
+	spin_box_label = memnew(Label);
+	spin_box_label->set_text(TTR("Floor:"));
+	spatial_editor_hb->add_child(spin_box_label);
 
 	floor = memnew(SpinBox);
 	floor->set_min(-32767);

modules/gridmap/grid_map_editor_plugin.h

@@ -82,6 +82,7 @@ class GridMapEditor : public VBoxContainer {
 	ConfirmationDialog *settings_dialog;
 	VBoxContainer *settings_vbc;
 	SpinBox *settings_pick_distance;
+	Label *spin_box_label;
 
 	struct SetItem {