Fix capsule height/radius setters with linked properties

Capsule height and radius setters can modify each other, rather than
using clamping, to avoid cases where values are not set correctly when
loading a scene (depending on the order of properties).

Inspector undo/redo:
Added the possibility to link properties together in the editor, so
they can be undone together, for cases where a property can modify
another one.

Gizmo undo/redo:
Capsule handles pass both radius and height values so they can be undone
together.

8 files changed, 55 insertions, 24 deletions

diff --git a/core/object/class_db.cpp b/core/object/class_db.cpp
index c58fe7bc24..75145e1b65 100644
--- a/core/object/class_db.cpp
+++ b/core/object/class_db.cpp
@@ -1068,6 +1068,20 @@ void ClassDB::set_property_default_value(const StringName &p_class, const String
 	default_values[p_class][p_name] = p_default;
 }
 
+void ClassDB::add_linked_property(const StringName &p_class, const String &p_property, const String &p_linked_property) {
+#ifdef TOOLS_ENABLED
+	OBJTYPE_WLOCK;
+	ClassInfo *type = classes.getptr(p_class);
+	ERR_FAIL_COND(!type);
+
+	ERR_FAIL_COND(!type->property_map.has(p_property));
+	ERR_FAIL_COND(!type->property_map.has(p_linked_property));
+
+	PropertyInfo &pinfo = type->property_map[p_property];
+	pinfo.linked_properties.push_back(p_linked_property);
+#endif
+}
+
 void ClassDB::get_property_list(const StringName &p_class, List<PropertyInfo> *p_list, bool p_no_inheritance, const Object *p_validator) {
 	OBJTYPE_RLOCK;
 
diff --git a/core/object/class_db.h b/core/object/class_db.h
index 6a7b39c230..8add0285f7 100644
--- a/core/object/class_db.h
+++ b/core/object/class_db.h
@@ -354,6 +354,7 @@ public:
 	static void add_property_subgroup(const StringName &p_class, const String &p_name, const String &p_prefix = "");
 	static void add_property(const StringName &p_class, const PropertyInfo &p_pinfo, const StringName &p_setter, const StringName &p_getter, int p_index = -1);
 	static void set_property_default_value(const StringName &p_class, const StringName &p_name, const Variant &p_default);
+	static void add_linked_property(const StringName &p_class, const String &p_property, const String &p_linked_property);
 	static void get_property_list(const StringName &p_class, List<PropertyInfo> *p_list, bool p_no_inheritance = false, const Object *p_validator = nullptr);
 	static bool get_property_info(const StringName &p_class, const StringName &p_property, PropertyInfo *r_info, bool p_no_inheritance = false, const Object *p_validator = nullptr);
 	static bool set_property(Object *p_object, const StringName &p_property, const Variant &p_value, bool *r_valid = nullptr);
diff --git a/core/object/object.h b/core/object/object.h
index 63d38120f6..94531f1cd0 100644
--- a/core/object/object.h
+++ b/core/object/object.h
@@ -143,6 +143,7 @@ enum PropertyUsageFlags {
 #define ADD_PROPERTY_DEFAULT(m_property, m_default) ::ClassDB::set_property_default_value(get_class_static(), m_property, m_default)
 #define ADD_GROUP(m_name, m_prefix) ::ClassDB::add_property_group(get_class_static(), m_name, m_prefix)
 #define ADD_SUBGROUP(m_name, m_prefix) ::ClassDB::add_property_subgroup(get_class_static(), m_name, m_prefix)
+#define ADD_LINKED_PROPERTY(m_property, m_linked_property) ::ClassDB::add_linked_property(get_class_static(), m_property, m_linked_property)
 
 struct PropertyInfo {
 	Variant::Type type = Variant::NIL;
@@ -152,6 +153,10 @@ struct PropertyInfo {
 	String hint_string;
 	uint32_t usage = PROPERTY_USAGE_DEFAULT;
 
+#ifdef TOOLS_ENABLED
+	Vector<String> linked_properties;
+#endif
+
 	_FORCE_INLINE_ PropertyInfo added_usage(uint32_t p_fl) const {
 		PropertyInfo pi = *this;
 		pi.usage |= p_fl;
diff --git a/editor/editor_inspector.cpp b/editor/editor_inspector.cpp
index 9de8b0451a..b3ce11028b 100644
--- a/editor/editor_inspector.cpp
+++ b/editor/editor_inspector.cpp
@@ -2243,6 +2243,13 @@ void EditorInspector::_edit_set(const String &p_name, const Variant &p_value, bo
 		undo_redo->add_do_property(object, p_name, p_value);
 		undo_redo->add_undo_property(object, p_name, object->get(p_name));
 
+		PropertyInfo prop_info;
+		if (ClassDB::get_property_info(object->get_class_name(), p_name, &prop_info)) {
+			for (const String &linked_prop : prop_info.linked_properties) {
+				undo_redo->add_undo_property(object, linked_prop, object->get(linked_prop));
+			}
+		}
+
 		Variant v_undo_redo = (Object *)undo_redo;
 		Variant v_object = object;
 		Variant v_name = p_name;
diff --git a/editor/plugins/collision_shape_2d_editor_plugin.cpp b/editor/plugins/collision_shape_2d_editor_plugin.cpp
index 486f947e43..c2684305ef 100644
--- a/editor/plugins/collision_shape_2d_editor_plugin.cpp
+++ b/editor/plugins/collision_shape_2d_editor_plugin.cpp
@@ -50,12 +50,7 @@ Variant CollisionShape2DEditor::get_handle_value(int idx) const {
 	switch (shape_type) {
 		case CAPSULE_SHAPE: {
 			Ref<CapsuleShape2D> capsule = node->get_shape();
-
-			if (idx == 0) {
-				return capsule->get_radius();
-			} else if (idx == 1) {
-				return capsule->get_height();
-			}
+			return Vector2(capsule->get_radius(), capsule->get_height());
 
 		} break;
 
@@ -209,17 +204,17 @@ void CollisionShape2DEditor::commit_handle(int idx, Variant &p_org) {
 		case CAPSULE_SHAPE: {
 			Ref<CapsuleShape2D> capsule = node->get_shape();
 
+			Vector2 values = p_org;
+
 			if (idx == 0) {
 				undo_redo->add_do_method(capsule.ptr(), "set_radius", capsule->get_radius());
-				undo_redo->add_do_method(canvas_item_editor, "update_viewport");
-				undo_redo->add_undo_method(capsule.ptr(), "set_radius", p_org);
-				undo_redo->add_do_method(canvas_item_editor, "update_viewport");
 			} else if (idx == 1) {
 				undo_redo->add_do_method(capsule.ptr(), "set_height", capsule->get_height());
-				undo_redo->add_do_method(canvas_item_editor, "update_viewport");
-				undo_redo->add_undo_method(capsule.ptr(), "set_height", p_org);
-				undo_redo->add_undo_method(canvas_item_editor, "update_viewport");
 			}
+			undo_redo->add_do_method(canvas_item_editor, "update_viewport");
+			undo_redo->add_undo_method(capsule.ptr(), "set_radius", values[0]);
+			undo_redo->add_undo_method(capsule.ptr(), "set_height", values[1]);
+			undo_redo->add_undo_method(canvas_item_editor, "update_viewport");
 
 		} break;
 
diff --git a/editor/plugins/node_3d_editor_gizmos.cpp b/editor/plugins/node_3d_editor_gizmos.cpp
index 38510ff81e..a42f94ed3d 100644
--- a/editor/plugins/node_3d_editor_gizmos.cpp
+++ b/editor/plugins/node_3d_editor_gizmos.cpp
@@ -4114,7 +4114,7 @@ Variant CollisionShape3DGizmoPlugin::get_handle_value(const EditorNode3DGizmo *p
 
 	if (Object::cast_to<CapsuleShape3D>(*s)) {
 		Ref<CapsuleShape3D> cs2 = s;
-		return p_id == 0 ? cs2->get_radius() : cs2->get_height();
+		return Vector2(cs2->get_radius(), cs2->get_height());
 	}
 
 	if (Object::cast_to<CylinderShape3D>(*s)) {
@@ -4261,12 +4261,11 @@ void CollisionShape3DGizmoPlugin::commit_handle(const EditorNode3DGizmo *p_gizmo
 
 	if (Object::cast_to<CapsuleShape3D>(*s)) {
 		Ref<CapsuleShape3D> ss = s;
+		Vector2 values = p_restore;
+
 		if (p_cancel) {
-			if (p_id == 0) {
-				ss->set_radius(p_restore);
-			} else {
-				ss->set_height(p_restore);
-			}
+			ss->set_radius(values[0]);
+			ss->set_height(values[1]);
 			return;
 		}
 
@@ -4274,12 +4273,12 @@ void CollisionShape3DGizmoPlugin::commit_handle(const EditorNode3DGizmo *p_gizmo
 		if (p_id == 0) {
 			ur->create_action(TTR("Change Capsule Shape Radius"));
 			ur->add_do_method(ss.ptr(), "set_radius", ss->get_radius());
-			ur->add_undo_method(ss.ptr(), "set_radius", p_restore);
 		} else {
 			ur->create_action(TTR("Change Capsule Shape Height"));
 			ur->add_do_method(ss.ptr(), "set_height", ss->get_height());
-			ur->add_undo_method(ss.ptr(), "set_height", p_restore);
 		}
+		ur->add_undo_method(ss.ptr(), "set_radius", values[0]);
+		ur->add_undo_method(ss.ptr(), "set_height", values[1]);
 
 		ur->commit_action();
 	}
diff --git a/scene/resources/capsule_shape_2d.cpp b/scene/resources/capsule_shape_2d.cpp
index 596fa70f15..0818e4fd99 100644
--- a/scene/resources/capsule_shape_2d.cpp
+++ b/scene/resources/capsule_shape_2d.cpp
@@ -59,7 +59,10 @@ void CapsuleShape2D::_update_shape() {
 }
 
 void CapsuleShape2D::set_radius(real_t p_radius) {
-	radius = MIN(p_radius, height * 0.5);
+	radius = p_radius;
+	if (radius > height * 0.5) {
+		height = radius * 2.0;
+	}
 	_update_shape();
 }
 
@@ -68,7 +71,10 @@ real_t CapsuleShape2D::get_radius() const {
 }
 
 void CapsuleShape2D::set_height(real_t p_height) {
-	height = MAX(p_height, radius * 2);
+	height = p_height;
+	if (radius > height * 0.5) {
+		radius = height * 0.5;
+	}
 	_update_shape();
 }
 
@@ -105,6 +111,8 @@ void CapsuleShape2D::_bind_methods() {
 
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "radius"), "set_radius", "get_radius");
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "height"), "set_height", "get_height");
+	ADD_LINKED_PROPERTY("radius", "height");
+	ADD_LINKED_PROPERTY("height", "radius");
 }
 
 CapsuleShape2D::CapsuleShape2D() :
diff --git a/scene/resources/capsule_shape_3d.cpp b/scene/resources/capsule_shape_3d.cpp
index e267941d6a..afec7b1877 100644
--- a/scene/resources/capsule_shape_3d.cpp
+++ b/scene/resources/capsule_shape_3d.cpp
@@ -81,7 +81,7 @@ void CapsuleShape3D::_update_shape() {
 void CapsuleShape3D::set_radius(float p_radius) {
 	radius = p_radius;
 	if (radius > height * 0.5) {
-		radius = height * 0.5;
+		height = radius * 2.0;
 	}
 	_update_shape();
 	notify_change_to_owners();
@@ -94,7 +94,7 @@ float CapsuleShape3D::get_radius() const {
 void CapsuleShape3D::set_height(float p_height) {
 	height = p_height;
 	if (radius > height * 0.5) {
-		height = radius * 2;
+		radius = height * 0.5;
 	}
 	_update_shape();
 	notify_change_to_owners();
@@ -112,6 +112,8 @@ void CapsuleShape3D::_bind_methods() {
 
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "radius", PROPERTY_HINT_RANGE, "0.001,4096,0.001"), "set_radius", "get_radius");
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "height", PROPERTY_HINT_RANGE, "0.001,4096,0.001"), "set_height", "get_height");
+	ADD_LINKED_PROPERTY("radius", "height");
+	ADD_LINKED_PROPERTY("height", "radius");
 }
 
 CapsuleShape3D::CapsuleShape3D() :