From 0e344f0d0bec80f26295ac7bd1a093b32bd904a2 Mon Sep 17 00:00:00 2001
From: Yaohua Xiong <xiongyaohua@gmail.com>
Date: Tue, 28 Nov 2023 10:48:15 +0800
Subject: [PATCH] Path3D notify transform change to CSGPolygon

---
 modules/csg/csg_shape.cpp |  2 ++
 scene/3d/path_3d.cpp      | 12 ++++++++++--
 scene/3d/path_3d.h        | 10 ++++++----
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/modules/csg/csg_shape.cpp b/modules/csg/csg_shape.cpp
index 6082b468f7f..970cdcb3660 100644
--- a/modules/csg/csg_shape.cpp
+++ b/modules/csg/csg_shape.cpp
@@ -1826,11 +1826,13 @@ CSGBrush *CSGPolygon3D::_build_brush() {
 			if (path) {
 				path->disconnect("tree_exited", callable_mp(this, &CSGPolygon3D::_path_exited));
 				path->disconnect("curve_changed", callable_mp(this, &CSGPolygon3D::_path_changed));
+				path->set_update_callback(Callable());
 			}
 			path = current_path;
 			if (path) {
 				path->connect("tree_exited", callable_mp(this, &CSGPolygon3D::_path_exited));
 				path->connect("curve_changed", callable_mp(this, &CSGPolygon3D::_path_changed));
+				path->set_update_callback(callable_mp(this, &CSGPolygon3D::_path_changed));
 			}
 		}
 
diff --git a/scene/3d/path_3d.cpp b/scene/3d/path_3d.cpp
index e38375d339c..c42c43be940 100644
--- a/scene/3d/path_3d.cpp
+++ b/scene/3d/path_3d.cpp
@@ -50,6 +50,10 @@ Path3D::~Path3D() {
 	}
 }
 
+void Path3D::set_update_callback(Callable p_callback) {
+	update_callback = p_callback;
+}
+
 void Path3D::_notification(int p_what) {
 	switch (p_what) {
 		case NOTIFICATION_ENTER_TREE: {
@@ -67,8 +71,12 @@ void Path3D::_notification(int p_what) {
 		} break;
 
 		case NOTIFICATION_TRANSFORM_CHANGED: {
-			if (is_inside_tree() && debug_instance.is_valid()) {
-				RS::get_singleton()->instance_set_transform(debug_instance, get_global_transform());
+			if (is_inside_tree()) {
+				if (debug_instance.is_valid()) {
+					RS::get_singleton()->instance_set_transform(debug_instance, get_global_transform());
+				}
+
+				update_callback.call();
 			}
 		} break;
 	}
diff --git a/scene/3d/path_3d.h b/scene/3d/path_3d.h
index 6116e980540..4a75954bebe 100644
--- a/scene/3d/path_3d.h
+++ b/scene/3d/path_3d.h
@@ -37,15 +37,15 @@
 class Path3D : public Node3D {
 	GDCLASS(Path3D, Node3D);
 
+private:
 	Ref<Curve3D> curve;
-
-	void _curve_changed();
-
 	RID debug_instance;
 	Ref<ArrayMesh> debug_mesh;
 
-private:
+	Callable update_callback; // Used only by CSG currently.
+
 	void _update_debug_mesh();
+	void _curve_changed();
 
 protected:
 	void _notification(int p_what);
@@ -53,6 +53,8 @@ protected:
 	static void _bind_methods();
 
 public:
+	void set_update_callback(Callable p_callback);
+
 	void set_curve(const Ref<Curve3D> &p_curve);
 	Ref<Curve3D> get_curve() const;