Add powered neon wire rendering

world.lua

@@ -494,6 +494,20 @@ function World:wireSwitchColorsAt(room, localCell, circuitId)
 	return colors
 end
 
+-- A valid wire is bright only while every switch at its sole terminal cell is
+-- pressed.  Rendering reads this derived state rather than entity sprite flags
+-- so every segment of a cross-room component agrees in the same frame.
+function World:wirePoweredAt(room, localCell, circuitId)
+	local worldCell = self:worldCell(room, localCell)
+	local component = worldCell and self.circuitComponents and
+		self.circuitComponents[circuitId] and self.circuitComponents[circuitId][cellKey(worldCell)]
+	if not component or not component.valid then return false end
+	for switch in pairs(component.switches) do
+		if not (self.circuitState and self.circuitState.switchPressed[switch]) then return false end
+	end
+	return true
+end
+
 function World:wireColorAt(room, localCell, circuitId, visibleColors)
 	local colors = self:wireSwitchColorsAt(room, localCell, circuitId)
 	if not colors then return nil end