Add enemy threat overlay

scripts/scenes/battle_scene.gd

@@ -13,6 +13,8 @@ const SKILL_OVERLAY_COLOR := Color(0.56, 0.28, 0.95, 0.28)
 const ITEM_OVERLAY_COLOR := Color(0.24, 0.74, 0.34, 0.30)
 const FORMATION_OVERLAY_COLOR := Color(0.95, 0.76, 0.25, 0.34)
 const OBJECTIVE_OVERLAY_COLOR := Color(1.0, 0.78, 0.18, 0.30)
+const THREAT_OVERLAY_COLOR := Color(1.0, 0.12, 0.10, 0.18)
+const THREAT_BORDER_COLOR := Color(1.0, 0.16, 0.12, 0.44)
 const BGM_MENU_PATH := "res://audio/bgm/menu_theme_placeholder.wav"
 const BGM_BATTLE_PATH := "res://audio/bgm/battle_loop_placeholder.wav"
 const SFX_BOW_RELEASE_PATH := "res://audio/sfx/bow_release_01.wav"
@@ -48,8 +50,10 @@ var move_cells: Array[Vector2i] = []
 var attack_cells: Array[Vector2i] = []
 var skill_cells: Array[Vector2i] = []
 var item_cells: Array[Vector2i] = []
+var threat_cells: Array[Vector2i] = []
 var selected_skill_id := ""
 var selected_item_id := ""
+var show_threat_overlay := false
 var active_scenario_id := ""
 var battle_started := false
 var battle_result_applied := false
@@ -124,6 +128,7 @@ var item_list: VBoxContainer
 var equip_button: Button
 var equip_menu: VBoxContainer
 var equip_list: VBoxContainer
+var threat_button: Button
 var restart_button: Button
 var new_campaign_button: Button
 var log_box: RichTextLabel
@@ -280,6 +285,12 @@ func _create_hud() -> void:
 	equip_button.pressed.connect(_on_equip_pressed)
 	button_row.add_child(equip_button)
 
+	threat_button = Button.new()
+	threat_button.text = "Threat"
+	threat_button.toggle_mode = true
+	threat_button.pressed.connect(_on_threat_pressed)
+	button_row.add_child(threat_button)
+
 	end_turn_button = Button.new()
 	end_turn_button.text = "End Turn"
 	end_turn_button.pressed.connect(_on_end_turn_pressed)
@@ -875,6 +886,8 @@ func _handle_key(event: InputEventKey) -> void:
 		_on_item_pressed()
 	elif event.keycode == KEY_E and not _is_input_locked():
 		_on_equip_pressed()
+	elif event.keycode == KEY_Y and not _is_prep_menu_visible():
+		_on_threat_pressed()
 
 
 func _process(delta: float) -> void:
@@ -932,6 +945,11 @@ func _draw_overlays() -> void:
 		draw_rect(objective_rect, OBJECTIVE_OVERLAY_COLOR)
 		draw_rect(objective_rect.grow(-5.0), Color(1.0, 0.88, 0.30, 0.82), false, 2.0)
 
+	for cell in threat_cells:
+		var threat_rect := _rect_for_cell(cell)
+		draw_rect(threat_rect, THREAT_OVERLAY_COLOR)
+		draw_rect(threat_rect.grow(-6.0), THREAT_BORDER_COLOR, false, 1.5)
+
 	for cell in move_cells:
 		draw_rect(_rect_for_cell(cell), Color(0.16, 0.55, 0.95, 0.28))
 
@@ -1328,6 +1346,9 @@ func _refresh_ranges() -> void:
 	attack_cells.clear()
 	skill_cells.clear()
 	item_cells.clear()
+	threat_cells.clear()
+	if show_threat_overlay and battle_started and state.battle_status == BattleState.STATUS_ACTIVE:
+		threat_cells = state.get_threat_cells(BattleState.TEAM_ENEMY)
 	var selected := state.get_selected_unit()
 	if selected.is_empty():
 		selected_skill_id = ""
@@ -1403,6 +1424,9 @@ func _update_hud() -> void:
 
 	end_turn_button.disabled = not state.can_player_act() or _is_input_locked()
 	restart_button.disabled = campaign_complete_screen
+	if threat_button != null:
+		threat_button.button_pressed = show_threat_overlay
+		threat_button.disabled = not battle_started or state.battle_status != BattleState.STATUS_ACTIVE or campaign_complete_screen
 
 
 func _update_cell_info() -> void:
@@ -1422,6 +1446,10 @@ func _update_cell_info() -> void:
 	]
 	if state.get_objective_cells().has(cell):
 		text += "\nObjective marker"
+	if show_threat_overlay:
+		var threat_names := state.get_threatening_unit_names(cell, BattleState.TEAM_ENEMY)
+		if not threat_names.is_empty():
+			text += "\nThreatened by %s" % _compact_name_list(threat_names, 3)
 
 	var unit: Dictionary = summary["unit"]
 	if not unit.is_empty():
@@ -1448,6 +1476,16 @@ func _update_cell_info() -> void:
 	cell_info_label.text = text
 
 
+func _compact_name_list(names: Array[String], limit: int) -> String:
+	var visible_names: Array[String] = []
+	var safe_limit: int = maxi(1, limit)
+	for index in range(mini(names.size(), safe_limit)):
+		visible_names.append(names[index])
+	if names.size() > safe_limit:
+		visible_names.append("+%d" % (names.size() - safe_limit))
+	return _join_strings(visible_names, ", ")
+
+
 func _update_forecast() -> void:
 	var selected := state.get_selected_unit()
 	if selected.is_empty() or not state.is_inside(hover_cell):
@@ -1963,6 +2001,17 @@ func _on_equip_pressed() -> void:
 	queue_redraw()
 
 
+func _on_threat_pressed() -> void:
+	if not battle_started or state.battle_status != BattleState.STATUS_ACTIVE or campaign_complete_screen:
+		if threat_button != null:
+			threat_button.button_pressed = show_threat_overlay
+		return
+	show_threat_overlay = not show_threat_overlay
+	_refresh_ranges()
+	_update_hud()
+	queue_redraw()
+
+
 func _on_restart_pressed() -> void:
 	if campaign_complete_screen:
 		return