降低所有背景的亮度，优化部分背景性能

parts/backgrounds/league.lua

@@ -0,0 +1,36 @@
+--Space with stars
+local gc=love.graphics
+local back={}
+
+local upCover do
+	local L={1,64}
+	for i=0,63 do
+		table.insert(L,{'setCL',.6,1,1,i*.01})
+		table.insert(L,{'fRect',0,63-i,1,1})
+	end
+	upCover=DOGC(L)
+end
+local downCover do
+	local L={1,64}
+	for i=0,63 do
+		table.insert(L,{'setCL',1,.5,.8,i*.01})
+		table.insert(L,{'fRect',0,i,1,1})
+	end
+	downCover=DOGC(L)
+end
+
+local W,H
+function back.init()
+	BG.resize(SCR.w,SCR.h)
+end
+function back.resize(w,h)
+	W,H=w,h
+end
+function back.update()
+end
+function back.draw()
+	gc.clear(.1,.1,.1)
+	gc.draw(upCover,0,0,0,W,H*.3/64)
+	gc.draw(downCover,0,H*.7,0,W,H*.3/64)
+end
+return back