refactor(M03): extract WMO render resource cache state

src/scenes/streaming/streaming_world_loader.gd

@@ -21,6 +21,9 @@ const WMO_RENDER_BUILD_STEP_PLANNER_SCRIPT := preload(
 const WMO_RENDER_BUILD_QUEUE_SCRIPT := preload(
 	"res://src/render/wmo/wmo_render_build_queue.gd"
 )
+const WMO_RENDER_RESOURCE_CACHE_STATE_SCRIPT := preload(
+	"res://src/render/wmo/wmo_render_resource_cache_state.gd"
+)
 const M2_BUILDER_SCRIPT := preload("res://addons/mpq_extractor/loaders/m2_builder.gd")
 const M2_NATIVE_ANIMATED_BUILDER_SCRIPT := preload("res://addons/mpq_extractor/loaders/m2_native_animated_builder.gd")
 const M2_NATIVE_ANIMATOR_SCRIPT := preload("res://src/scenes/streaming/m2_native_animator.gd")
@@ -280,9 +283,7 @@ var _tile_mesh_cache: Dictionary = {}
 var _tile_mesh_cache_order: Array = []
 var _terrain_quality_mesh_cache: RefCounted = TERRAIN_QUALITY_MESH_CACHE_SCRIPT.new()
 var _wmo_prototype_cache: Dictionary = {}
-var _wmo_render_cache: Dictionary = {}
-var _wmo_render_missing_cache: Dictionary = {}
-var _wmo_render_load_requests: Dictionary = {}
+var _wmo_render_resource_cache_state := WMO_RENDER_RESOURCE_CACHE_STATE_SCRIPT.new()
 var _wmo_render_build_queue := WMO_RENDER_BUILD_QUEUE_SCRIPT.new()
 var _wmo_scene_resource_cache: Dictionary = {}
 var _wmo_scene_cache_missing: Dictionary = {}
@@ -467,9 +468,8 @@ func _release_runtime_caches_for_shutdown() -> void:
 	_m2_mesh_cache.clear()
 	_m2_static_animation_cache.clear()
 	_m2_missing_cache.clear()
-	_wmo_render_cache.clear()
+	_wmo_render_resource_cache_state.clear_all()
 	_wmo_scene_resource_cache.clear()
-	_wmo_render_missing_cache.clear()
 	_wmo_scene_cache_missing.clear()
 	_wmo_missing_cache.clear()
 	_shared_tex_cache.clear()
@@ -1005,7 +1005,11 @@ func _log_hitch_profile(start_usec: int, timings: Array[String], did_refresh: bo
 		_m2_animation_finalize_queue.size() + _m2_animation_load_requests.size(),
 		_m2_mesh_finalize_queue.size() + _m2_mesh_load_requests.size(),
 		_m2_build_queue.size(),
-		_wmo_build_queue.size() + _wmo_scene_load_requests.size() + _wmo_render_load_requests.size(),
+		(
+			_wmo_build_queue.size()
+			+ _wmo_scene_load_requests.size()
+			+ _wmo_render_resource_cache_state.pending_request_count()
+		),
 		_wmo_render_build_queue.pending_count(),
 		_tile_lod_create_queue.size(),
 		_tile_lod_remove_queue.size(),
@@ -1032,7 +1036,11 @@ func render_baseline_snapshot() -> Dictionary:
 			"m2_animation": _m2_animation_finalize_queue.size() + _m2_animation_load_requests.size(),
 			"m2_mesh": _m2_mesh_finalize_queue.size() + _m2_mesh_load_requests.size(),
 			"m2_build": _m2_build_queue.size(),
-			"wmo_build": _wmo_build_queue.size() + _wmo_scene_load_requests.size() + _wmo_render_load_requests.size(),
+			"wmo_build": (
+				_wmo_build_queue.size()
+				+ _wmo_scene_load_requests.size()
+				+ _wmo_render_resource_cache_state.pending_request_count()
+			),
 			"wmo_groups": _wmo_render_build_queue.pending_count(),
 			"lod_create": _tile_lod_create_queue.size(),
 			"lod_remove": _tile_lod_remove_queue.size(),
@@ -1314,7 +1322,11 @@ func _tick_runtime_stats(delta: float) -> void:
 		_m2_animation_finalize_queue.size() + _m2_animation_load_requests.size(),
 		_m2_mesh_finalize_queue.size() + _m2_mesh_load_requests.size(),
 		_m2_build_queue.size(),
-		_wmo_build_queue.size() + _wmo_scene_load_requests.size() + _wmo_render_load_requests.size(),
+		(
+			_wmo_build_queue.size()
+			+ _wmo_scene_load_requests.size()
+			+ _wmo_render_resource_cache_state.pending_request_count()
+		),
 		_wmo_render_build_queue.pending_count(),
 		_tile_lod_create_queue.size(),
 		_tile_lod_remove_queue.size(),
@@ -2356,15 +2368,17 @@ func _wait_for_tile_tasks() -> void:
 			ResourceLoader.load_threaded_get(path)
 	_wmo_scene_load_requests.clear()
 
-	for path_variant in _wmo_render_load_requests.values():
+	var wmo_render_request_paths := (
+		_wmo_render_resource_cache_state.request_paths_snapshot()
+	)
+	for path_variant in wmo_render_request_paths.values():
 		var path := String(path_variant)
 		if path.is_empty():
 			continue
 		var status := ResourceLoader.load_threaded_get_status(path)
 		if status == ResourceLoader.THREAD_LOAD_IN_PROGRESS or status == ResourceLoader.THREAD_LOAD_LOADED:
 			ResourceLoader.load_threaded_get(path)
-	_wmo_render_load_requests.clear()
-	_wmo_render_missing_cache.clear()
+	_wmo_render_resource_cache_state.clear_transient_state()
 	_wmo_scene_cache_missing.clear()
 	_wmo_render_build_queue.clear()
 
@@ -3002,8 +3016,7 @@ func _clear_streamed_world() -> void:
 	_wmo_build_jobs.clear()
 	_wmo_build_queue.clear()
 	_wmo_scene_load_requests.clear()
-	_wmo_render_load_requests.clear()
-	_wmo_render_missing_cache.clear()
+	_wmo_render_resource_cache_state.clear_transient_state()
 	_wmo_scene_cache_missing.clear()
 	_wmo_render_build_queue.clear()
 
@@ -3589,7 +3602,7 @@ func _process_wmo_build_jobs() -> void:
 						var normalized_rel := _wmo_placement_resolver.normalize_relative_path(
 							rel_path
 						)
-						if _wmo_render_load_requests.has(normalized_rel):
+						if _wmo_render_resource_cache_state.has_request(normalized_rel):
 							advance_job = false
 						else:
 							var scene := _get_wmo_scene_or_request(rel_path)
@@ -3667,15 +3680,15 @@ func _drain_wmo_scene_loads() -> void:
 
 
 func _drain_wmo_render_loads() -> void:
-	for normalized_rel_variant in _wmo_render_load_requests.keys():
+	var request_paths := _wmo_render_resource_cache_state.request_paths_snapshot()
+	for normalized_rel_variant in request_paths.keys():
 		var normalized_rel := String(normalized_rel_variant)
-		var path := String(_wmo_render_load_requests[normalized_rel])
+		var path := String(request_paths[normalized_rel])
 		var status := ResourceLoader.load_threaded_get_status(path)
 		if status != ResourceLoader.THREAD_LOAD_LOADED and status != ResourceLoader.THREAD_LOAD_FAILED:
 			continue
-		_wmo_render_load_requests.erase(normalized_rel)
 		if status != ResourceLoader.THREAD_LOAD_LOADED:
-			_wmo_render_missing_cache[normalized_rel] = true
+			_wmo_render_resource_cache_state.complete_request_as_missing(normalized_rel)
 			continue
 		var resource: Resource = ResourceLoader.load_threaded_get(path)
 		if (
@@ -3683,20 +3696,23 @@ func _drain_wmo_render_loads() -> void:
 				and resource.get_script() == WMO_STREAMING_SCRIPT
 				and int(resource.get("format_version")) >= WMO_STREAMING_SCRIPT.FORMAT_VERSION
 		):
-			_wmo_render_cache[normalized_rel] = resource
+			_wmo_render_resource_cache_state.complete_request_with_resource(
+				normalized_rel,
+				resource
+			)
 		else:
-			_wmo_render_missing_cache[normalized_rel] = true
+			_wmo_render_resource_cache_state.complete_request_as_missing(normalized_rel)
 
 
 func _get_wmo_render_or_request(rel_path: String) -> Resource:
 	var normalized_rel := _wmo_placement_resolver.normalize_relative_path(rel_path)
 	if normalized_rel.is_empty():
 		return null
-	if _wmo_render_cache.has(normalized_rel):
-		return _wmo_render_cache[normalized_rel]
-	if _wmo_render_missing_cache.has(normalized_rel):
+	if _wmo_render_resource_cache_state.contains_resource(normalized_rel):
+		return _wmo_render_resource_cache_state.resource_for(normalized_rel)
+	if _wmo_render_resource_cache_state.is_missing(normalized_rel):
 		return null
-	if _wmo_render_load_requests.has(normalized_rel):
+	if _wmo_render_resource_cache_state.has_request(normalized_rel):
 		return null
 
 	var cache_path := wmo_render_cache_dir.path_join(normalized_rel.get_basename() + ".res")
@@ -3709,7 +3725,7 @@ func _get_wmo_render_or_request(rel_path: String) -> Resource:
 		false,
 		ResourceLoader.CACHE_MODE_REUSE)
 	if err == OK or err == ERR_BUSY:
-		_wmo_render_load_requests[normalized_rel] = cache_path
+		_wmo_render_resource_cache_state.remember_request(normalized_rel, cache_path)
 	return null