fix: make sure that some variable doesn't leak to the global namespace

sonic-bluestreak.love/game/modules/world/actors/parent.lua

@@ -7,7 +7,7 @@ function Parent:new(world, type, x, y, z, w, h, d, isSolid)
 end
 
 function Parent:draw()
-  drawx, drawy, drawz = self.x, self.y, self.z
+  local drawx, drawy, drawz = self.x, self.y, self.z
   if (self.world.maptype == "shoot") then
     drawx = drawx + math.floor(drawy/2)
   end
@@ -22,6 +22,8 @@ function Parent:draw()
 end
 
 function Parent:drawShadow(x, y)
+  local x = x or 0
+  local y = y or 0
 if (self.world.maptype == "shoot") then
   x = x + math.floor(y/2)
 end