Fix grid drawing

funcs.lua

@@ -87,10 +87,10 @@ end
 
 ---Round a number with specified unit
 ---@param n number
----@param u? number # Default: 10
+---@param u? number|1
 ---@return number
 function math.roundUnit(n,u)
-    local u = u or 10
+    local u = u or 1
     return math.floor(n/u+.5)*u
 end