fix many warnings (26F-Studio#889)

* fix many warnings

some of them can be solved by using a prototype-based system
maybe I can try to use some of these systems to reform backgrounds...

* Update app_mahjong.lua

---------

Co-authored-by: MrZ_26 <[email protected]>

Author: ImpleLee

main.lua

@@ -334,7 +334,7 @@ SKIN.load{
 SFX.init((function()--[Warning] Not loading files here, just get the list of sound needed
     local L={}
     for _,v in next,fs.getDirectoryItems('media/effect/chiptune/') do
-        if FILE.isSafe('media/effect/chiptune/'..v,"Dangerous file : %SAVE%/media/effect/chiptune/"..v) then
+        if FILE.isSafe('media/effect/chiptune/'..v) then
             table.insert(L,v:sub(1,-5))
         end
     end
@@ -343,7 +343,7 @@ end)())
 BGM.init((function()
     local L={}
     for _,v in next,fs.getDirectoryItems('media/music') do
-        if FILE.isSafe('media/music/'..v,"Dangerous file : %SAVE%/media/music/"..v) then
+        if FILE.isSafe('media/music/'..v) then
             L[v:sub(1,-5)]='media/music/'..v
         end
     end

parts/backgrounds/aura.lua

@@ -5,7 +5,6 @@ local t
 
 function back.init()
     t=math.random()*2600
-    BG.resize(SCR.w,SCR.h)
 end
 function back.update(dt)
     t=(t+dt)%6200

parts/backgrounds/bg2.lua

@@ -5,7 +5,6 @@ local shader=SHADER.grad2
 local t
 function back.init()
     t=math.random()*2600
-    BG.resize(nil,SCR.h)
 end
 function back.update(dt)
     t=(t+dt)%6200

parts/backgrounds/rainbow.lua

@@ -5,7 +5,6 @@ local shader=SHADER.rgb1
 local t
 function back.init()
     t=math.random()*2600
-    BG.resize(SCR.w,SCR.h)
 end
 function back.update(dt)
     t=(t+dt)%6200

parts/backgrounds/rainbow2.lua

@@ -5,7 +5,6 @@ local shader=SHADER.rgb2
 local t
 function back.init()
     t=math.random()*2600
-    BG.resize(SCR.w,SCR.h)
 end
 function back.update(dt)
     t=(t+dt)%6200

parts/bot/init.lua

@@ -92,7 +92,7 @@ function BOT.new(P,data)
             P:setHold(1)
         end
 
-        local cc=cc or REQUIRE"CCloader"
+        local cc=REQUIRE"CCloader"
         if not cc then
             data.type=false
             return BOT.new(P,data)

parts/eventsets/blindMesDisp.lua

@@ -6,6 +6,6 @@ return {
         PLY.draw.applyField(P)
         GC.setColor(1,1,1,.1)
         GC.draw(IMG.electric,0,106,0,2.6)
-        PLY.draw.cancelField(P)
+        PLY.draw.cancelField()
     end,
 }

parts/eventsets/secret_grade.lua

@@ -64,7 +64,7 @@ return {
                 end
             end end
         end
-        PLY.draw.cancelField(P)
+        PLY.draw.cancelField()
     end,
     task=function(P)
         P.modeData.rankPts=1

parts/eventsets/techrash_u.lua

@@ -9,7 +9,7 @@ return {
             GC.setColor(1,.3,.3,.5-i*.04)
             GC.rectangle('fill',30*L[i]-30,0,30,600)
         end
-        PLY.draw.cancelField(P)
+        PLY.draw.cancelField()
     end,
     hook_drop=function(P)
         local C=P.lastPiece

parts/eventsets/tsd_h.lua

@@ -8,7 +8,7 @@ return {
             PLY.draw.applyField(P)
             GC.setColor(1,.3,.3,.2)
             GC.rectangle('fill',30*L[1]-30,0,30,600)
-            PLY.draw.cancelField(P)
+            PLY.draw.cancelField()
         end
     end,
     hook_drop=function(P)