Add instancing to behavior tree

bt/behavior_tree.cpp

@@ -2,6 +2,7 @@
 
 #include "behavior_tree.h"
 #include "core/class_db.h"
+#include "core/error_macros.h"
 #include "core/list.h"
 #include "core/object.h"
 #include "core/variant.h"
@@ -32,6 +33,13 @@ Ref<BehaviorTree> BehaviorTree::clone() const {
 	return copy;
 }
 
+Ref<BTTask> BehaviorTree::instance(Object *p_agent, const Ref<Blackboard> &p_blackboard) const {
+	ERR_FAIL_COND_V_MSG(root_task == nullptr, memnew(BTTask), "Trying to instance a behavior tree with no valid root task.");
+	Ref<BTTask> inst = root_task->clone();
+	inst->initialize(p_agent, p_blackboard);
+	return inst;
+}
+
 void BehaviorTree::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_description", "p_value"), &BehaviorTree::set_description);
 	ClassDB::bind_method(D_METHOD("get_description"), &BehaviorTree::get_description);
@@ -39,6 +47,7 @@ void BehaviorTree::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_root_task"), &BehaviorTree::get_root_task);
 	ClassDB::bind_method(D_METHOD("init"), &BehaviorTree::init);
 	ClassDB::bind_method(D_METHOD("clone"), &BehaviorTree::clone);
+	ClassDB::bind_method(D_METHOD("instance", "p_agent", "p_blackboard"), &BehaviorTree::instance);
 
 	ADD_PROPERTY(PropertyInfo(Variant::STRING, "description", PROPERTY_HINT_MULTILINE_TEXT), "set_description", "get_description");
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "root_task", PROPERTY_HINT_RESOURCE_TYPE, "BTTask"), "set_root_task", "get_root_task");

bt/behavior_tree.h

@@ -3,10 +3,10 @@
 #ifndef BEHAVIOR_TREE_H
 #define BEHAVIOR_TREE_H
 
+#include "bt_task.h"
 #include "core/object.h"
 #include "core/resource.h"
-
-#include "bt_task.h"
+#include "modules/limboai/blackboard.h"
 
 class BehaviorTree : public Resource {
 	GDCLASS(BehaviorTree, Resource);
@@ -33,6 +33,7 @@ public:
 
 	void init();
 	Ref<BehaviorTree> clone() const;
+	Ref<BTTask> instance(Object *p_agent, const Ref<Blackboard> &p_blackboard) const;
 };
 
 #endif // BEHAVIOR_TREE_H

bt/bt_player.cpp

@@ -21,8 +21,7 @@ void BTPlayer::_load_tree() {
 	ERR_FAIL_COND_MSG(!behavior_tree.is_valid(), "BTPlayer needs a valid behavior tree.");
 	ERR_FAIL_COND_MSG(!behavior_tree->get_root_task().is_valid(), "Behavior tree has no valid root task.");
 	_loaded_tree = behavior_tree;
-	_root_task = _loaded_tree->get_root_task()->clone();
-	_root_task->initialize(get_owner(), blackboard);
+	_root_task = _loaded_tree->instance(get_owner(), blackboard);
 }
 
 void BTPlayer::set_behavior_tree(const Ref<BehaviorTree> &p_tree) {

bt/bt_task.cpp

@@ -93,7 +93,8 @@ void BTTask::initialize(Object *p_agent, const Ref<Blackboard> &p_blackboard) {
 Ref<BTTask> BTTask::clone() const {
 	Ref<BTTask> inst = duplicate(false);
 	inst->parent = nullptr;
-	CRASH_COND(inst->get_parent().is_valid());
+	inst->agent = nullptr;
+	inst->blackboard.unref();
 	for (int i = 0; i < children.size(); i++) {
 		Ref<BTTask> c = get_child(i)->clone();
 		c->parent = inst.ptr();
@@ -186,6 +187,11 @@ void BTTask::remove_child(Ref<BTTask> p_child) {
 	}
 }
 
+void BTTask::remove_child_at_index(int p_idx) {
+	ERR_FAIL_INDEX(p_idx, get_child_count());
+	children.remove(p_idx);
+}
+
 bool BTTask::has_child(const Ref<BTTask> &p_child) const {
 	return children.find(p_child) != -1;
 }
@@ -277,6 +283,7 @@ void BTTask::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("add_child", "p_child"), &BTTask::add_child);
 	ClassDB::bind_method(D_METHOD("add_child_at_index", "p_child", "p_idx"), &BTTask::add_child_at_index);
 	ClassDB::bind_method(D_METHOD("remove_child", "p_child"), &BTTask::remove_child);
+	ClassDB::bind_method(D_METHOD("remove_child_at_index", "p_idx"), &BTTask::remove_child_at_index);
 	ClassDB::bind_method(D_METHOD("has_child", "p_child"), &BTTask::has_child);
 	ClassDB::bind_method(D_METHOD("is_descendant_of", "p_task"), &BTTask::is_descendant_of);
 	ClassDB::bind_method(D_METHOD("get_child_index", "p_child"), &BTTask::get_child_index);

bt/bt_task.h

@@ -57,8 +57,8 @@ public:
 	void set_custom_name(const String &p_name);
 	String get_task_name() const;
 
-	virtual void initialize(Object *p_agent, const Ref<Blackboard> &p_blackboard);
 	virtual Ref<BTTask> clone() const;
+	virtual void initialize(Object *p_agent, const Ref<Blackboard> &p_blackboard);
 	int execute(float p_delta);
 	void cancel();
 	Ref<BTTask> get_child(int p_idx) const;
@@ -66,6 +66,7 @@ public:
 	void add_child(Ref<BTTask> p_child);
 	void add_child_at_index(Ref<BTTask> p_child, int p_idx);
 	void remove_child(Ref<BTTask> p_child);
+	void remove_child_at_index(int p_idx);
 	bool has_child(const Ref<BTTask> &p_child) const;
 	bool is_descendant_of(const Ref<BTTask> &p_task) const;
 	int get_child_index(const Ref<BTTask> &p_child) const;

bt/decorators/bt_subtree.cpp

@@ -11,6 +11,7 @@
 #include "modules/limboai/bt/actions/bt_fail.h"
 #include "modules/limboai/bt/bt_task.h"
 #include "modules/limboai/bt/decorators/bt_decorator.h"
+#include "modules/limboai/bt/decorators/bt_new_scope.h"
 
 String BTSubtree::_generate_name() const {
 	String s;
@@ -24,16 +25,18 @@ String BTSubtree::_generate_name() const {
 	return vformat("Subtree %s", s);
 }
 
-Ref<BTTask> BTSubtree::clone() const {
-	Ref<BTTask> copy = BTDecorator::clone();
-	if (!Engine::get_singleton()->is_editor_hint()) {
-		ERR_FAIL_COND_V_MSG(!subtree.is_valid(), copy, "Subtree is not assigned.");
-		ERR_FAIL_COND_V_MSG(!subtree->get_root_task().is_valid(), copy, "Subtree root task is not valid.");
-		ERR_FAIL_COND_V_MSG(get_child_count() != 0, copy, "Subtree prototype shouldn't have children.");
+void BTSubtree::initialize(Object *p_agent, const Ref<Blackboard> &p_blackboard) {
+	ERR_FAIL_COND_MSG(!subtree.is_valid(), "Subtree is not assigned.");
+	ERR_FAIL_COND_MSG(!subtree->get_root_task().is_valid(), "Subtree root task is not valid.");
+	ERR_FAIL_COND_MSG(get_child_count() != 0, "Subtree task shouldn't have children during initialization.");
 
-		copy->add_child(subtree->get_root_task()->clone());
-	}
-	return copy;
+	// while (get_child_count() > 0) {
+	// 	remove_child_at_index(get_child_count() - 1);
+	// }
+
+	add_child(subtree->get_root_task()->clone());
+
+	BTNewScope::initialize(p_agent, p_blackboard);
 }
 
 int BTSubtree::_tick(float p_delta) {

bt/decorators/bt_subtree.h

@@ -26,7 +26,7 @@ public:
 	}
 	Ref<BehaviorTree> get_subtree() const { return subtree; }
 
-	virtual Ref<BTTask> clone() const;
+	virtual void initialize(Object *p_agent, const Ref<Blackboard> &p_blackboard);
 	virtual String get_configuration_warning() const;
 };