Add powered neon wire rendering

room.lua

@@ -239,12 +239,21 @@ function Room:drawWiresAt(originX, originY, cellSize, selectedCircuit, editorCol
 						for _, line in ipairs(lines) do love.graphics.line(line) end
 						local wireBlend = (editorColors or not switchColors) and "alpha" or "screen"
 						love.graphics.setBlendMode(wireBlend)
+						local previousShader = love.graphics.getShader()
+						if not editorColors and switchColors and wireNeonShader then
+							local powered = gameWorld:wirePoweredAt(self, localCell, circuitId)
+							wireNeonShader:send("wirePower", powered and 1 or 0)
+							wireNeonShader:send("wireTime", love.timer.getTime())
+							wireNeonShader:send("wirePhase", (#circuitId * 0.137) + x * 0.071 + y * 0.113)
+							love.graphics.setShader(wireNeonShader)
+						end
 						love.graphics.setLineWidth(math.max(1, cellSize * 0.045))
 						for _, color in ipairs(drawColors) do
 							love.graphics.setColor(color[1], color[2], color[3], selected and 1 or 0.32)
 							for _, line in ipairs(lines) do love.graphics.line(line) end
 							love.graphics.circle("fill", cx, cy, math.max(0.75, cellSize * 0.0275))
 						end
+						love.graphics.setShader(previousShader)
 					end
 				end
 			end

shaders.lua

@@ -89,6 +89,45 @@ goopShader = love.graphics.newShader[[
   }
 ]]
 
+-- Wires are drawn as primitives rather than textured sprites, but LÖVE still
+-- runs this shader over its default white texture. Inactive runs stay visibly
+-- connected at half brightness; powered runs get a travelling neon shimmer,
+-- occasional tube-like noise, and a sub-pixel bend rather than a global fade.
+wireNeonShader = love.graphics.newShader[[
+  extern number wirePower;
+  extern number wireTime;
+  extern number wirePhase;
+
+  float wireHash(vec2 point) {
+    return fract(sin(dot(point, vec2(127.1, 311.7))) * 43758.5453123);
+  }
+
+  vec4 position(mat4 transformProjection, vec4 vertexPosition) {
+    if (wirePower < 0.5) return transformProjection * vertexPosition;
+
+    // Every segment sharing an endpoint receives the same offset, so corners
+    // stay connected while the live current gives the tube a gentle movement.
+    float wave = sin(vertexPosition.x * 0.085 + vertexPosition.y * 0.13 +
+      wireTime * 4.4 + wirePhase * 9.0);
+    float wobble = wave * 0.32;
+    vertexPosition.xy += vec2(wobble, -wobble * 0.55);
+    return transformProjection * vertexPosition;
+  }
+
+  vec4 effect(vec4 color, Image texture, vec2 textureCoords, vec2 screenCoords) {
+    if (wirePower < 0.5) return vec4(color.rgb * 0.50, color.a * 0.72);
+
+    float travel = dot(screenCoords, vec2(0.070, 0.043)) - wireTime * 6.8 + wirePhase * 13.0;
+    float shimmer = sin(travel) * 0.075 + sin(travel * 2.37 + 1.7) * 0.035;
+    vec2 noiseCell = floor(screenCoords * 0.34) + floor(wireTime * 15.0) * vec2(1.0, -1.0);
+    float noise = wireHash(noiseCell + wirePhase);
+    float flicker = max(0.0, noise - 0.82) * 0.32;
+    float brightness = 0.92 + shimmer + flicker;
+    float alpha = 0.84 + shimmer * 0.80 + flicker * 0.55;
+    return vec4(color.rgb * brightness, color.a * alpha);
+  }
+]]
+
 function drawGoopySprite(sprite, x, y, scale)
 	local w, h = sprite:getWidth(), sprite:getHeight()
 	local time = love.timer.getTime()

tests/test_wire.lua

@@ -169,6 +169,15 @@ test("a switchless wire component has no gameplay color", function()
 	assertTrue(world:wireColorAt(roomA, {x = 1, y = 1}, "circuit_a") == nil)
 end)
 
+test("wire power follows its terminal switch", function()
+	local world, roomA = makeWorld()
+	world:resolveCircuits()
+	assertFalse(world:wirePoweredAt(roomA, {x = 1, y = 1}, "circuit_a"))
+	world.collidableMatrices.blue[1] = {[4] = {}}
+	world:resolveCircuits()
+	assertTrue(world:wirePoweredAt(roomA, {x = 1, y = 1}, "circuit_a"))
+end)
+
 test("a door requires every independent switch run at its terminal", function()
 	local greenSwitch = switch("green", 1, 2)
 	local world, roomA, _, wiredDoor = makeWorld()

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