keep direction for an more optimised moving scheme

src/main.lua

@@ -292,45 +292,43 @@ local function getnearestunplaced(buf, pbuf, cx,cy,cz,co, sx,sz, setceiling)
     end
     return selected
 end
-local function moveto(x,y,cx,cz)
+local function center(direction, wanted)
-    local direction = 0
-    local function center(wanted)
         if direction == 1 and wanted ~= 1 then
             move("left")
         end
         if direction == -1 and wanted ~= -1 then
             move("right")
         end
-    end
+end
+local function moveto(x,y,cx,cz,direction)
     while x ~= cx or y ~= cz do
         if x > cx then -- x
-            center()
+            center(direction)
             cx = cx + 1
             move("forward")
         end
         if x < cx then
-            center()
+            center(direction)
             cx = cx - 1
             move("back")
         end
 
         if y > cz then -- z
-            center(1)
+            center(direction, 1)
             cz = cz + 1
             move("right")
             move("forward")
             direction = 1
         end
         if y < cz then
-            center(-1)
+            center(direction, -1)
             cz = cz - 1
             move("left")
             move("forward")
             direction = -1
         end
     end
-    center()
+    return cx,cz,direction
-    return cx,cz
 end
 local function printdes(buf, dimensions)
     move("up")
@@ -338,13 +336,14 @@ local function printdes(buf, dimensions)
 
     local cx = 1
     local cz = 1
+    local direction = 0
     for cy=1,dimensions["y"],1 do
         for _=1,3,1 do -- build walls
             local pbuf = {}
             while true do
                 local target = getnearestunplaced(buf, pbuf, cx,cy,cz,nil, dimensions["x"],dimensions["z"], false)
                 if not target then break end
-                cx,cz = moveto(target[1],target[2],cx,cz)
+                cx,cz = moveto(target[1],target[2],cx,cz,direction)
                 place("down")
                 pbuf[posasstring(cx,cy,cz)] = true
             end
@@ -376,16 +375,17 @@ local function printdes(buf, dimensions)
         -- build ceiling/floor
         for _cz=1,dimensions["z"],1 do
             for _cx=1,dimensions["x"],1 do
-                moveto(_cx,_cz,cx,cz)
+                moveto(_cx,_cz,cx,cz,direction)
                 if buf[posasstring(_cx,cy,_cz)] ~= 2 then
                     place("down")
                 end
             end
         end
         -- return to standard pos but +1 to y
-        moveto(1,1,cx,cz)
+        moveto(1,1,cx,cz,direction)
         move("up")
     end
+    center(direction)
 end
 
 while true do