diff --git a/src/main.lua b/src/main.lua
index 5592e9d..567d47a 100644
--- a/src/main.lua
+++ b/src/main.lua
@@ -83,7 +83,25 @@ local function newdesign()
     }
     local currentfloor = 1
     local camx,camy = 0,0
-
+    local currentblock = 2
+    local blockindex = 1
+    local blocks = {
+        2, -- no ceiling
+        3, -- doorway
+        4, -- glass
+    }
+    local function renderblock(index)
+        local block = blocks[index]
+        if block == 2 then -- no ceiling
+            term.blit("C", colors.toBlit(colors.black), colors.toBlit(colors.red))
+        end
+        if block == 3 then -- doorway
+            term.blit("D", colors.toBlit(colors.black), colors.toBlit(colors.brown))
+        end
+        if block == 4 then -- glass
+            term.blit("W", colors.toBlit(colors.black), colors.toBlit(colors.white))
+        end
+    end
 
     while true do
         -- render buf
@@ -94,8 +112,9 @@ local function newdesign()
                 term.setCursorPos(x, z)
                 if currentbuf == 1 then -- wall
                     term.blit(" ", colors.toBlit(colors.white), colors.toBlit(colors.white))
-                elseif currentbuf == 2 then -- no ceiling
-                    term.blit(" ", colors.toBlit(colors.red), colors.toBlit(colors.red))
+                elseif currentbuf > 1 then -- blocks
+                    renderblock(currentbuf-1)
+                    --term.blit("C", colors.toBlit(colors.black), colors.toBlit(colors.red))
                 elseif currentbuf == 0 or currentbuf == nil then -- nothing
                     term.blit("\127", colors.toBlit(colors.gray), colors.toBlit(colors.black))
                 end
@@ -109,6 +128,8 @@ local function newdesign()
         term.write("x: "..tostring(camx))
         term.write(" z: "..tostring(camy))
         term.write(" floor: "..tostring(currentfloor))
+        term.write(" Block: ")
+        renderblock(blockindex)
 
         -- user input
         local event = table.pack(os.pullEvent())
@@ -119,14 +140,23 @@ local function newdesign()
                 if event[2] == 1 then -- left button, set
                     buf[posasstring(event[3], currentfloor, event[4])] = 1
                 end
-                if event[2] == 3 then -- middle button, set no ceiling
-                    buf[posasstring(event[3], currentfloor, event[4])] = 2
+                if event[2] == 3 then -- middle button, set special block
+                    buf[posasstring(event[3], currentfloor, event[4])] = currentblock
                 end
                 if event[2] == 2 then -- right button, erase
                     buf[posasstring(event[3], currentfloor, event[4])] = 0
                 end
             end
         end
+        if event[1] == "mouse_scroll" then
+            if event[2] == 1 then -- down
+                if blockindex == #blocks then blockindex = 1 else blockindex = blockindex + 1 end
+            end
+            if event[2] == -1 then -- up
+                if blockindex == 1 then blockindex = #blocks else blockindex = blockindex - 1 end
+            end
+            currentblock = blocks[blockindex]
+        end
         if event[1] == "key" then
             if keys.getName(event[2]) == "leftCtrl" then -- menu
                 local action = selopt({
@@ -272,7 +302,7 @@ local function placebuf(buf, x, y, z)
         place("down")
     end
 end
-local function getnearestunplaced(buf, pbuf, cx,cy,cz,co, sx,sz)
+local function getnearestunplaced(buf, pbuf, cx,cy,cz,clayer, sx,sz)
     local distance = math.huge
     local selected = nil
 
@@ -280,7 +310,15 @@ local function getnearestunplaced(buf, pbuf, cx,cy,cz,co, sx,sz)
         for y=1,sz,1 do
             local needplace = buf[posasstring(x,cy,y)]
             if pbuf[posasstring(x,cy,y)] then needplace = 0 end -- already placed
-            needplace = needplace == 1
+            if clayer == 0 or clayer == 2 then
+                needplace = needplace == 1
+            end
+            if clayer == 1 then
+                needplace = needplace == 1 or needplace == 4
+            end
+            if clayer == 3 then
+                needplace = needplace == 1 or needplace == 4 or needplace == 3
+            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)
                 if cd < distance then
@@ -371,10 +409,10 @@ local function printdes(buf, dimensions)
     local cz = 1
     local direction = 0
     for cy=1,dimensions["y"],1 do
-        for _=1,3,1 do -- build walls
+        for clayer=1,3,1 do -- build walls
             local pbuf = {}
             while true do
-                local target = getnearestunplaced(buf, pbuf, cx,cy,cz,nil, dimensions["x"],dimensions["z"])
+                local target = getnearestunplaced(buf, pbuf, cx,cy,cz,clayer, dimensions["x"],dimensions["z"])
                 if not target then break end
 
                 render(buf, pbuf, cx,cy,cz, target[1],target[2], dimensions["x"],dimensions["z"], {1})
@@ -400,7 +438,7 @@ local function printdes(buf, dimensions)
             end
         end
         while true do
-            local target = getnearestunplaced(cbuf, pbuf, cx,0,cz,nil, dimensions["x"],dimensions["z"])
+            local target = getnearestunplaced(cbuf, pbuf, cx,0,cz,0, dimensions["x"],dimensions["z"])
             if not target then break end
 
             render(cbuf, pbuf, cx,0,cz, target[1],target[2], dimensions["x"],dimensions["z"], {1})