feat: add esc_current_scene reserved global (#474)

Co-authored-by: Duncan Brown <duncan@bhs-consultants.com>

addons/escoria-core/game/core-scripts/esc/commands/change_scene.gd

@@ -66,13 +66,14 @@ func run(command_params: Array) -> int:
 	# exit_scene event. Also room selector actions require the transition.
 	if command_params[1] \
 			and (
-				not escoria.globals_manager.get_global("ESC_LAST_SCENE").empty()
+				not escoria.globals_manager.get_global( \
+					escoria.room_manager.GLOBAL_LAST_SCENE).empty()
 				or (
 					escoria.event_manager.get_running_event("_front") != null \
 					and escoria.event_manager.get_running_event("_front").name \
 						in ["newgame", "exit_scene", "room_selector"]
 						and escoria.globals_manager.get_global(
-							"ESC_LAST_SCENE"
+							escoria.room_manager.GLOBAL_LAST_SCENE
 						).empty()
 					)
 				):
@@ -91,16 +92,18 @@ func run(command_params: Array) -> int:
 		escoria.game_scene.unpause_game()
 
 	# If FORCE_LAST_SCENE_NULL is true, force ESC_LAST_SCENE to empty
-	if escoria.globals_manager.get_global("FORCE_LAST_SCENE_NULL"):
+	if escoria.globals_manager.get_global( \
+		escoria.room_manager.GLOBAL_FORCE_LAST_SCENE_NULL):
+
 		escoria.globals_manager.set_global(
-			"ESC_LAST_SCENE", 
+			escoria.room_manager.GLOBAL_LAST_SCENE, 
 			null, 
 			true
 		)
 	elif escoria.main.current_scene:
 		# If FORCE_LAST_SCENE_NULL is false, set ESC_LAST_SCENE = current roomid
 		escoria.globals_manager.set_global(
-			"ESC_LAST_SCENE", 
+			escoria.room_manager.GLOBAL_LAST_SCENE, 
 			escoria.main.current_scene.global_id, 
 			true
 		)
@@ -150,6 +153,14 @@ func run(command_params: Array) -> int:
 		room_scene.game = escoria.game_scene
 		escoria.main.set_scene(room_scene)
 		
+		# We know the scene has been loaded. Make its global ID available for
+		# use by ESC script.
+		escoria.globals_manager.set_global(
+			escoria.room_manager.GLOBAL_CURRENT_SCENE, 
+			room_scene.global_id, 
+			true
+		)
+
 		# Clear queued resources
 		escoria.resource_cache.clear()
 		

addons/escoria-core/game/core-scripts/esc/esc_globals_manager.gd

@@ -5,30 +5,16 @@ extends Resource
 class_name ESCGlobalsManager
 
 
-const GLOBAL_ANIMATION_RESOURCES = "ANIMATION_RESOURCES"
-
-
 # Emitted when a global is changed
 signal global_changed(global, old_value, new_value)
 
 
-# A list of reserved globals which can not be overridden
-const RESERVED_GLOBALS = [
-	"ESC_LAST_SCENE",		# Contains the global_id of previous room
-	"FORCE_LAST_SCENE_NULL",	# If true, ESC_LAST_SCENE is not considered for 
-							# automatic transitions
-	"ANIMATION_RESOURCES"
-]
-
-
 # The globals registry
 export(Dictionary) var _globals = {}
 
 
-
-func _init():
-	set_global("ESC_LAST_SCENE", "", true)
-	set_global("FORCE_LAST_SCENE_NULL", false, true)
+# Registry of globals that are to be reserved for internal use only.
+var _reserved_globals: Dictionary = {}
 
 
 # Check if a global was registered
@@ -41,6 +27,27 @@ func has(key: String) -> bool:
 	return _globals.has(key)
 
 
+# Registers a global as being reserved and initializes it.
+#
+# #### Parameters
+#
+# - key: The key of the global to register
+# - value: The initial value (optional)
+func register_reserved_global(key: String, value = null) -> void:
+	if key in _reserved_globals:
+		escoria.logger.report_errors(
+			"ESCGlobalsManager.register_reserved_global: Can not override reserved global",
+			[
+				"Global key %s is already registered as reserved" % key
+			]
+		)
+	_reserved_globals[key] = value
+	_globals[key] = value
+	
+	if value != null:
+		emit_signal("global_changed", key, _globals[key], value)
+	
+
 # Get the current value of a global
 #
 # #### Parameters
@@ -77,7 +84,7 @@ func filter(pattern: String) -> Dictionary:
 # - key: The key of the global to modify
 # - value: The new value
 func set_global(key: String, value, ignore_reserved: bool = false) -> void:
-	if key in RESERVED_GLOBALS and not ignore_reserved:
+	if key in _reserved_globals and not ignore_reserved:
 		escoria.logger.report_errors(
 			"ESCGlobalsManager.set_global: Can not override reserved global",
 			[

addons/escoria-core/game/core-scripts/esc/esc_room_manager.gd

@@ -0,0 +1,32 @@
+extends Object
+class_name ESCRoomManager
+
+
+# Reserved globals which can not be overridden; prefixed with "GLOBAL_"
+#
+# Contains the global_id of previous room
+const GLOBAL_LAST_SCENE = "ESC_LAST_SCENE"
+
+# If true, ESC_LAST_SCENE is not considered for automatic transitions
+const GLOBAL_FORCE_LAST_SCENE_NULL = "FORCE_LAST_SCENE_NULL"
+
+const GLOBAL_ANIMATION_RESOURCES = "ANIMATION_RESOURCES"
+
+# Contains the global_id of the current room
+const GLOBAL_CURRENT_SCENE = "ESC_CURRENT_SCENE"
+
+# Dict of the reserved globals to register and their initial values.
+const RESERVED_GLOBALS = {
+	GLOBAL_LAST_SCENE: "",
+	GLOBAL_FORCE_LAST_SCENE_NULL: false,
+	GLOBAL_ANIMATION_RESOURCES: [],
+	GLOBAL_CURRENT_SCENE: ""
+}
+
+
+# Registers all reserved global flags for use.
+func register_reserved_globals() -> void:
+	for key in RESERVED_GLOBALS:
+		escoria.globals_manager.register_reserved_global( \
+			key, 
+			RESERVED_GLOBALS[key])

addons/escoria-core/game/core-scripts/esc_room.gd

@@ -96,10 +96,10 @@ func _ready():
 			true
 		)
 		if escoria.globals_manager.has(
-			escoria.globals_manager.GLOBAL_ANIMATION_RESOURCES
+			escoria.room_manager.GLOBAL_ANIMATION_RESOURCES
 		):
 			var animations = escoria.globals_manager.get_global(
-				escoria.globals_manager.GLOBAL_ANIMATION_RESOURCES
+				escoria.room_manager.GLOBAL_ANIMATION_RESOURCES
 			)
 			
 			if player.global_id in animations and \
@@ -168,7 +168,8 @@ func perform_script_events():
 		if enabled_automatic_transitions \
 				or (
 					not enabled_automatic_transitions \
-					and escoria.globals_manager.get_global("FORCE_LAST_SCENE_NULL")
+					and escoria.globals_manager.get_global( \
+						escoria.room_manager.GLOBAL_FORCE_LAST_SCENE_NULL)
 				):
 			var script_transition_in = escoria.esc_compiler.compile([
 				":transition_in",
@@ -195,18 +196,28 @@ func perform_script_events():
 		
 		# Now that :ready is finished, if FORCE_LAST_SCENE_NULL was true, reset it 
 		# to false
-		if escoria.globals_manager.get_global("FORCE_LAST_SCENE_NULL"):
+		if escoria.globals_manager.get_global( \
+			escoria.room_manager.GLOBAL_FORCE_LAST_SCENE_NULL):
+
 			escoria.globals_manager.set_global(
-				"FORCE_LAST_SCENE_NULL", 
+				escoria.room_manager.GLOBAL_FORCE_LAST_SCENE_NULL, 
 				false, 
 				true
 			)
 			escoria.globals_manager.set_global(
-				"ESC_LAST_SCENE",
+				escoria.room_manager.GLOBAL_LAST_SCENE,
 				escoria.main.current_scene.global_id \
 						if escoria.main.current_scene != null else "", 
 				true
 			)
+		
+		# Make the room's global ID available for use in ESC script.
+		escoria.globals_manager.set_global(
+			escoria.room_manager.GLOBAL_CURRENT_SCENE,
+			escoria.main.current_scene.global_id \
+					if escoria.main.current_scene != null else "", 
+			true
+		)
 
 
 # Runs the script event from the script attached, if any.