diff --git a/dotscape b/dotscape
index 1ce6a99..496043d 100755
Binary files a/dotscape and b/dotscape differ
diff --git a/fcore/app-with.sml b/fcore/app-with.sml
index 78c88d0..a1cade8 100644
--- a/fcore/app-with.sml
+++ b/fcore/app-with.sml
@@ -999,4 +999,62 @@ struct
       , modalNum = 0
       }
     end
+
+  fun useLayerTree (app: app_type, layerTree, canvasWidth, canvasHeight) :
+    app_type =
+    let
+      val
+        { mode
+        , mouseX
+        , mouseY
+        , xClickPoints
+        , yClickPoints
+        , windowWidth
+        , windowHeight
+        , arrowX = _
+        , arrowY = _
+        , canvasWidth = _
+        , canvasHeight = _
+
+        , showGraph
+        , openFilePath
+        , fileBrowser
+        , fileBrowserIdx
+        , r
+        , g
+        , b
+        , a
+        , layer
+        , layerTree = _
+        , modalNum
+        } = app
+
+      val arrowX = 0
+      val arrowY = 0
+    in
+      { mode = mode
+      , mouseX = mouseX
+      , mouseY = mouseY
+      , arrowX = arrowX
+      , arrowY = arrowY
+      , canvasWidth = canvasWidth
+      , canvasHeight = canvasHeight
+      , windowWidth = windowWidth
+      , windowHeight = windowHeight
+      , xClickPoints = xClickPoints
+      , yClickPoints = yClickPoints
+
+      , showGraph = showGraph
+      , openFilePath = openFilePath
+      , fileBrowser = fileBrowser
+      , fileBrowserIdx = fileBrowserIdx
+      , r = r
+      , g = g
+      , b = b
+      , a = a
+      , layer = layer
+      , layerTree = layerTree
+      , modalNum = modalNum
+      }
+    end
 end
diff --git a/fcore/browse-mode.sml b/fcore/browse-mode.sml
index 60470f3..27ae264 100644
--- a/fcore/browse-mode.sml
+++ b/fcore/browse-mode.sml
@@ -161,7 +161,5 @@ struct
     | FILE_BROWSER_AND_PATH {fileBrowser, path} =>
         handleFileBrowserAndPathInBrowseMode (model, fileBrowser, path)
     | SQUARES_LOAD_ERROR => CommonUpdate.squaresLoadError model
-    | USE_SQUARES squares =>
-        CommonUpdate.useSquaresInNormalMode (model, squares)
     | _ => (model, [])
 end
diff --git a/fcore/normal-mode.sml b/fcore/normal-mode.sml
index 6e451d3..a8f88bf 100644
--- a/fcore/normal-mode.sml
+++ b/fcore/normal-mode.sml
@@ -134,36 +134,25 @@ struct
 
   fun realToInt x = Real32.toInt IEEEReal.TO_NEAREST x
 
-  fun changePixel (model: app_type, hIdx, vIdx, pixel) =
+  fun getDrawMessage (model: app_type) =
     let
       val
-        { windowWidth
+        { canvasWidth
+        , canvasHeight
+        , layerTree
+        , windowWidth
         , windowHeight
         , xClickPoints
         , yClickPoints
-        , canvasWidth
-        , canvasHeight
-        , layer
-        , layerTree
-        , r
-        , g
-        , b
-        , a
+        , arrowX
+        , arrowY
         , ...
         } = model
 
       val maxSide = Int.max (canvasWidth, canvasHeight)
-
-      val xpos = Vector.sub (xClickPoints, hIdx)
-      val ypos = Vector.sub (yClickPoints, vIdx)
-
-      val layerTree = LayerTree.addPixel
-        (layer, hIdx, vIdx, maxSide, pixel, layerTree)
-      val model = AppWith.layerTree (model, layerTree, hIdx, vIdx)
-
       val squares = LayerTree.flatten (maxSide, layerTree)
 
-      val dotVec = getDotVecFromIndices (model, hIdx, vIdx)
+      val dotVec = getDotVecFromIndices (model, arrowX, arrowY)
 
       val squares = CollisionTree.toTriangles
         ( windowWidth
@@ -180,6 +169,19 @@ struct
       (model, [DRAW drawMsg])
     end
 
+  fun changePixel (model: app_type, hIdx, vIdx, pixel) =
+    let
+      val {canvasWidth, canvasHeight, layer, layerTree, ...} = model
+
+      val maxSide = Int.max (canvasWidth, canvasHeight)
+
+      val layerTree = LayerTree.addPixel
+        (layer, hIdx, vIdx, maxSide, pixel, layerTree)
+      val model = AppWith.layerTree (model, layerTree, hIdx, vIdx)
+    in
+      getDrawMessage model
+    end
+
   fun addPixel (model: app_type, hIdx, vIdx) =
     let
       val {r, g, b, a, ...} = model
@@ -332,8 +334,13 @@ struct
       updateCanvas (model, canvasWidth, canvasHeight)
     end
 
-  fun useSquares (model, squares, canvasWidth, canvasHeight) =
-    raise Fail "todo: reimplement"
+  fun useLayers (model, layerTree, canvasWidth, canvasHeight) =
+    let
+      val model =
+        AppWith.layerTree (model, layerTree, canvasWidth, canvasHeight)
+    in
+      getDrawMessage model
+    end
 
   fun enterBrowseMode model =
     let
@@ -382,8 +389,8 @@ struct
     | KEY_CTRL_L => CommonUpdate.getLoadSquaresMsg model
     | KEY_CTRL_E => CommonUpdate.getExportSquaresMsg model
     | KEY_CTRL_C => CommonUpdate.getCollisionMsg model
-    | USE_SQUARES {squares, canvasWidth, canvasHeight} =>
-        useSquares (model, squares, canvasWidth, canvasHeight)
+    | USE_LAYERS {tree, canvasWidth, canvasHeight} =>
+        useLayers (model, tree, canvasWidth, canvasHeight)
     | SQUARES_LOAD_ERROR => CommonUpdate.squaresLoadError model
     | KEY_CTRL_O => enterBrowseMode model
     | ARROW_UP => moveArrowUp model
diff --git a/fcore/parser/parser.sml b/fcore/parser/parser.sml
index abc7d16..7c5707c 100644
--- a/fcore/parser/parser.sml
+++ b/fcore/parser/parser.sml
@@ -42,7 +42,7 @@ struct
                  (tl, canvasWidth, canvasHeight, tree, 1)
              in
                case tokens of
-                 [T.R_BRACE] => SOME tree
+                 [T.R_BRACE] => SOME (canvasWidth, canvasHeight, tree)
                | _ => NONE
              end
          | _ => NONE)
diff --git a/imperative-shell/file-thread.sml b/imperative-shell/file-thread.sml
index a0a97b3..fb0ef7c 100644
--- a/imperative-shell/file-thread.sml
+++ b/imperative-shell/file-thread.sml
@@ -25,12 +25,15 @@ struct
       val () = TextIO.closeIn io
     in
       case Parser.parse str of
-        SOME (canvasWidth, canvasHeight, grid) =>
-          Mailbox.send (inputMailbox, USE_SQUARES
-            { squares = grid
-            , canvasWidth = canvasWidth
-            , canvasHeight = canvasHeight
-            })
+        SOME (canvasWidth, canvasHeight, tree) =>
+          Mailbox.send
+            ( inputMailbox
+            , USE_LAYERS
+                { tree = tree
+                , canvasWidth = canvasWidth
+                , canvasHeight = canvasHeight
+                }
+            )
       | NONE => ()
     end
 
diff --git a/message-types/input-msg.sml b/message-types/input-msg.sml
index e8929a1..dc71809 100644
--- a/message-types/input-msg.sml
+++ b/message-types/input-msg.sml
@@ -31,11 +31,7 @@ struct
   | ARROW_DOWN
   | KEY_ENTER
   | KEY_SPACE
-  | USE_SQUARES of
-      { squares: {r: int, g: int, b: int, a: int} vector vector
-      , canvasWidth: int
-      , canvasHeight: int
-      }
+  | USE_LAYERS of {tree: LayerTree.t, canvasWidth: int, canvasHeight: int}
   | SQUARES_LOAD_ERROR
   | FILE_BROWSER_AND_PATH of
       {fileBrowser: AppType.file_browser_item vector, path: string}