refactor code to provide newest needed argument to getnearestunplaced.

src/main.lua

@@ -361,12 +361,31 @@ local function placebuf(buf, x, y, z)
         place("down")
     end
 end
-local function getnearestunplaced(buf, pbuf, cx,cy,cz,clayer, sx,sz)
+local function directiondist(direction, wanted)
+    if direction == 0 then return 1 end
+    if direction == 1 and wanted == -1 then return 2 end
+    if direction == -1 and wanted == 1 then return 2 end
+
+    if direction ~= wanted then return 1 end -- failsafes
+    if direction == wanted then return 0 end
+end
+local function getnearestunplaced(buf, pbuf, cx,cy,cz,clayer, sx,sz, direction)
     local distance = math.huge
     local selected = nil
 
     for x=1,sx,1 do
         for y=1,sz,1 do
+            local extracost = 0
+            if x ~= cx and direction ~= 0 then
+                extracost = extracost + 1
+            end
+            if y > cz and direction ~= 1 then
+                extracost = extracost + directiondist(direction, 1)
+            end
+            if y < cz and direction ~= -1 then
+                extracost = extracost + directiondist(direction, -1)
+            end
+
             local needplace = buf[posasstring(x,cy,y)]
             if pbuf[posasstring(x,cy,y)] then needplace = 0 end -- already placed
             if clayer == 0 or clayer == 2 then
@@ -380,6 +399,7 @@ local function getnearestunplaced(buf, pbuf, cx,cy,cz,clayer, sx,sz)
             end
             if needplace then -- needs to be placed, calculate distance
                 local cd = math.abs(y-cz)+math.abs(x-cx) -- raw distance (amount of blocks between)
+                cd = cd + extracost
                 if cd < distance then
                     distance = cd
                     selected = {x,y}
@@ -479,7 +499,7 @@ local function printdes(buf, dimensions)
         for clayer=1,3,1 do -- build walls
             local pbuf = {}
             while true do
-                local target = getnearestunplaced(buf, pbuf, cx,cy,cz,clayer, dimensions["x"],dimensions["z"])
+                local target = getnearestunplaced(buf, pbuf, cx,cy,cz,clayer, dimensions["x"],dimensions["z"], direction)
                 if not target then break end
 
                 render(buf, pbuf, cx,cy,cz, target[1],target[2], dimensions["x"],dimensions["z"], setlists[clayer])
@@ -505,7 +525,7 @@ local function printdes(buf, dimensions)
             end
         end
         while true do
-            local target = getnearestunplaced(cbuf, pbuf, cx,0,cz,0, dimensions["x"],dimensions["z"])
+            local target = getnearestunplaced(cbuf, pbuf, cx,0,cz,0, dimensions["x"],dimensions["z"], direction)
             if not target then break end
 
             render(cbuf, pbuf, cx,0,cz, target[1],target[2], dimensions["x"],dimensions["z"], {1})