新背景：Tunnel

modes/GM.lua

@@ -30,7 +30,7 @@ return{
 				return true
 			end
 		end,
-		bg="welcome",bgm="far",
+		bg="tunnel",bgm="far",
 	},
 	slowMark=true,
 	load=function()

parts/backgrounds/tunnel.lua

@@ -0,0 +1,43 @@
+--Cool Tunnel
+local gc=love.graphics
+local rnd=math.random
+local ins,rem=table.insert,table.remove
+local back={}
+
+local ring
+local t
+local W,H
+function back.init()
+	ring={}
+	t=26
+	back.resize(SCR.w,SCR.h)
+end
+function back.resize(w,h)
+	W,H=w,h
+end
+function back.update(dt)
+	t=t-1
+	if t==0 then
+		t=rnd(26,62)
+		ins(ring,0)
+	end
+	for i=#ring,1,-1 do
+		ring[i]=ring[i]+dt
+		if ring[i]>3.55 then
+			rem(ring,i)
+		end
+	end
+end
+function back.draw()
+	gc.clear(.1,.1,.1)
+	gc.setColor(.4,.4,.4)
+	for i=1,#ring do
+		local r=ring[i]^2/12
+		gc.setLineWidth(30-15/(r+.5))
+		gc.rectangle("line",640-W*r/2,360-H*r/2,W*r,H*r)
+	end
+end
+function back.discard()
+	ring=nil
+end
+return back

parts/scenes/customGame.lua

@@ -166,7 +166,7 @@ WIDGET.init("customGame",{
 	--Else
 	WIDGET.newSelector({name="bg",
 		x=1070,	y=150,w=250,color="yellow",
-		list={"none","grey","glow","rgb","flink","wing","fan","badapple","welcome","aura","bg1","bg2","rainbow","rainbow2","lightning","lightning2","matrix","space"},
+		list={"none","grey","glow","rgb","flink","wing","fan","badapple","welcome","aura","bg1","bg2","rainbow","rainbow2","tunnel","lightning","lightning2","matrix","space"},
 		disp=WIDGET.lnk.CUSval("bg"),
 		code=function(i)CUSTOMENV.bg=i BG.set(i)end
 	}),