Add AnimationTree Advance Expressions

Allows specifying an expression as a condition for state machine transitions.

This gives much greater flexibility for creating complex state machines. By directly interfacing with the script code, it is possible to create complex animation advance condition for switching between states.

Ensure assigning AnimationTreeStateMachineTransition base expression node in editor is relative to current AnimationTree node.

Allow setting an expression base node on the AnimationTree itself.

Co-Authored-By: reduz <reduzio@gmail.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/scene/animation/animation_tree.h b/scene/animation/animation_tree.h
index b646efede4..0bfe615c9b 100644
--- a/scene/animation/animation_tree.h
+++ b/scene/animation/animation_tree.h
@@ -107,6 +107,7 @@ protected:
 	double blend_input(int p_input, double p_time, bool p_seek, bool p_seek_root, real_t p_blend, FilterAction p_filter = FILTER_IGNORE, bool p_optimize = true);
 
 	void make_invalid(const String &p_reason);
+	AnimationTree *get_animation_tree() const;
 
 	static void _bind_methods();
 
@@ -270,6 +271,7 @@ private:
 	HashSet<TrackCache *> playing_caches;
 
 	Ref<AnimationNode> root;
+	NodePath advance_expression_base_node = NodePath(String("."));
 
 	AnimationProcessCallback process_callback = ANIMATION_PROCESS_IDLE;
 	bool active = false;
@@ -332,6 +334,9 @@ public:
 	void set_animation_player(const NodePath &p_player);
 	NodePath get_animation_player() const;
 
+	void set_advance_expression_base_node(const NodePath &p_advance_expression_base_node);
+	NodePath get_advance_expression_base_node() const;
+
 	TypedArray<String> get_configuration_warnings() const override;
 
 	bool is_state_invalid() const;