From 7004ce5816adf4971e7e41c03b8e925cb44df11d Mon Sep 17 00:00:00 2001
From: Marc Gilleron <marc.gilleron@gmail.com>
Date: Sun, 17 Jul 2022 20:24:49 +0100
Subject: [PATCH] Auto-assign a mesher in editor for convenience

---
 terrain/fixed_lod/voxel_terrain.cpp        | 14 ++++++++++++++
 terrain/variable_lod/voxel_lod_terrain.cpp | 17 +++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/terrain/fixed_lod/voxel_terrain.cpp b/terrain/fixed_lod/voxel_terrain.cpp
index ec852ae5..33e46ab4 100644
--- a/terrain/fixed_lod/voxel_terrain.cpp
+++ b/terrain/fixed_lod/voxel_terrain.cpp
@@ -18,6 +18,9 @@
 #include "../../util/string_funcs.h"
 #include "../instancing/voxel_instancer.h"
 #include "../voxel_data_block_enter_info.h"
+#ifdef TOOLS_ENABLED
+#include "../../meshers/transvoxel/voxel_mesher_transvoxel.h"
+#endif
 
 #include <core/config/engine.h>
 #include <core/core_string_names.h>
@@ -862,6 +865,17 @@ void VoxelTerrain::_notification(int p_what) {
 	switch (p_what) {
 		case NOTIFICATION_ENTER_TREE:
 			set_process(true);
+#ifdef TOOLS_ENABLED
+			// In the editor, auto-configure a default mesher, for convenience.
+			// Because Godot has a property hint to automatically instantiate a resource, but if that resource is
+			// abstract, it doesn't work... and it cannot be a default value because such practice was deprecated with a
+			// warning in Godot 4.
+			if (Engine::get_singleton()->is_editor_hint() && !get_mesher().is_valid()) {
+				Ref<VoxelMesherTransvoxel> mesher;
+				mesher.instantiate();
+				set_mesher(mesher);
+			}
+#endif
 			break;
 
 		case NOTIFICATION_PROCESS:
diff --git a/terrain/variable_lod/voxel_lod_terrain.cpp b/terrain/variable_lod/voxel_lod_terrain.cpp
index 5c2ad7a7..78d7e8dc 100644
--- a/terrain/variable_lod/voxel_lod_terrain.cpp
+++ b/terrain/variable_lod/voxel_lod_terrain.cpp
@@ -20,6 +20,9 @@
 #include "../../util/thread/rw_lock.h"
 #include "../instancing/voxel_instancer.h"
 #include "voxel_lod_terrain_update_task.h"
+#ifdef TOOLS_ENABLED
+#include "../../meshers/transvoxel/voxel_mesher_transvoxel.h"
+#endif
 
 #include <core/config/engine.h>
 #include <core/core_string_names.h>
@@ -1116,6 +1119,20 @@ void VoxelLodTerrain::_notification(int p_what) {
 				break;
 			}
 
+#ifdef TOOLS_ENABLED
+		case NOTIFICATION_ENTER_TREE:
+			// In the editor, auto-configure a default mesher, for convenience.
+			// Because Godot has a property hint to automatically instantiate a resource, but if that resource is
+			// abstract, it doesn't work... and it cannot be a default value because such practice was deprecated with a
+			// warning in Godot 4.
+			if (Engine::get_singleton()->is_editor_hint() && !get_mesher().is_valid()) {
+				Ref<VoxelMesherTransvoxel> mesher;
+				mesher.instantiate();
+				set_mesher(mesher);
+			}
+			break;
+#endif
+
 		case NOTIFICATION_EXIT_TREE:
 			break;