render: extract animated M2 materializer

src/render/m2/m2_animated_instance_materializer.gd

@@ -0,0 +1,120 @@
+class_name M2AnimatedInstanceMaterializer
+extends RefCounted
+
+## Duplicates one ordered animated M2 batch, applies instance render settings,
+## starts playback and attaches a non-empty batch to the supplied parent.
+## All calls mutate Godot scene objects and therefore belong on the main thread.
+
+const M2_ANIMATED_SCENE_FINALIZER_SCRIPT := preload(
+	"res://src/render/m2/m2_animated_scene_finalizer.gd"
+)
+const M2_ANIMATION_PLAYBACK_CONTROLLER_SCRIPT := preload(
+	"res://src/render/m2/m2_animation_playback_controller.gd"
+)
+
+var _animated_scene_finalizer := M2_ANIMATED_SCENE_FINALIZER_SCRIPT.new()
+var _animation_playback_controller := M2_ANIMATION_PLAYBACK_CONTROLLER_SCRIPT.new()
+
+
+## Returns the attached batch root and detached diagnostic entries. Invalid or
+## empty input, and a batch whose duplicates all fail, returns an empty result.
+## The caller owns the returned/attached batch through `m2_parent_root`.
+func materialize_batch(
+	m2_parent_root: Node3D,
+	relative_path: String,
+	prototype: Node3D,
+	transforms: Array,
+	start_index: int,
+	instance_count: int,
+	batch_serial: int,
+	visibility_range_end: float,
+	visibility_range_margin: float,
+	cast_shadows: bool,
+	native_animator_script: Script,
+	collect_native_diagnostics: bool
+) -> Dictionary:
+	if (
+		m2_parent_root == null
+		or transforms.is_empty()
+		or instance_count <= 0
+		or prototype == null
+	):
+		return {}
+
+	var model_name := relative_path.get_file().get_basename()
+	var batch_root := Node3D.new()
+	batch_root.name = "%s_anim_%d" % [model_name, batch_serial]
+	var diagnostic_entries: Array[Dictionary] = []
+	for batch_offset in instance_count:
+		var instance_index := start_index + batch_offset
+		var instance := prototype.duplicate(
+			Node.DUPLICATE_SIGNALS | Node.DUPLICATE_GROUPS | Node.DUPLICATE_SCRIPTS
+		) as Node3D
+		if instance == null:
+			continue
+		instance.name = "%s_%d" % [model_name, instance_index]
+		instance.transform = transforms[instance_index]
+		_apply_visibility_range_recursive(
+			instance,
+			visibility_range_end,
+			visibility_range_margin
+		)
+		_apply_shadow_cast_recursive(instance, cast_shadows)
+		_animation_playback_controller.copy_native_animator_data(
+			prototype,
+			instance,
+			native_animator_script
+		)
+		batch_root.add_child(instance)
+		var animation_players := _animated_scene_finalizer.animation_players_in_subtree(
+			instance
+		)
+		var native_diagnostics := _animation_playback_controller.start_instance_playback(
+			instance,
+			relative_path,
+			instance_index,
+			native_animator_script,
+			animation_players,
+			collect_native_diagnostics
+		)
+		for native_diagnostic in native_diagnostics:
+			diagnostic_entries.append({
+				"instance_index": instance_index,
+				"state": native_diagnostic,
+			})
+
+	if batch_root.get_child_count() <= 0:
+		batch_root.queue_free()
+		return {}
+	m2_parent_root.add_child(batch_root)
+	return {
+		"batch_root": batch_root,
+		"native_diagnostics": diagnostic_entries,
+	}
+
+
+func _apply_visibility_range_recursive(
+	node: Node,
+	range_end: float,
+	range_end_margin: float
+) -> void:
+	if range_end <= 0.0:
+		return
+	if node is GeometryInstance3D:
+		var geometry := node as GeometryInstance3D
+		geometry.visibility_range_end = range_end
+		geometry.visibility_range_end_margin = range_end_margin
+	for child in node.get_children():
+		_apply_visibility_range_recursive(child, range_end, range_end_margin)
+
+
+func _apply_shadow_cast_recursive(node: Node, cast_shadows: bool) -> void:
+	if node is GeometryInstance3D:
+		var geometry := node as GeometryInstance3D
+		geometry.cast_shadow = (
+			GeometryInstance3D.SHADOW_CASTING_SETTING_ON
+			if cast_shadows
+			else GeometryInstance3D.SHADOW_CASTING_SETTING_OFF
+		)
+	for child in node.get_children():
+		_apply_shadow_cast_recursive(child, cast_shadows)