progress moving away from 'squares' field to layer tree

fcore/normal-mode.sml

@@ -134,7 +134,7 @@ struct
 
   fun realToInt x = Real32.toInt IEEEReal.TO_NEAREST x
 
-  fun changeSquare (model: app_type, hIdx, vIdx, fModel) =
+  fun changePixel (model: app_type, hIdx, vIdx, pixel) =
     let
       val
         { windowWidth
@@ -143,18 +143,28 @@ struct
         , yClickPoints
         , canvasWidth
         , canvasHeight
+        , layer
+        , layerTree
+        , r
+        , g
+        , b
+        , a
         , ...
         } = model
 
+      val maxSide = Int.max (canvasWidth, canvasHeight)
+
       val xpos = Vector.sub (xClickPoints, hIdx)
       val ypos = Vector.sub (yClickPoints, vIdx)
 
-      val model = fModel (model, hIdx, vIdx, hIdx, vIdx)
-      val squares = #squares model
+      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 maxSide = Int.max (canvasWidth, canvasHeight)
       val squares = CollisionTree.toTriangles
         ( windowWidth
         , windowHeight
@@ -170,22 +180,27 @@ struct
       (model, [DRAW drawMsg])
     end
 
-  fun addCoordinates (model, hIdx, vIdx) =
-    changeSquare (model, hIdx, vIdx, AppWith.addSquare)
+  fun addPixel (model: app_type, hIdx, vIdx) =
+    let
+      val {r, g, b, a, ...} = model
+      val pixel = {r = r, g = g, b = b, a = a}
+    in
+      changePixel (model, hIdx, vIdx, pixel)
+    end
+
+  fun deletePixel (model, hIdx, vIdx) =
+    changePixel (model, hIdx, vIdx, Grid.emptyPixel)
 
   fun mouseLeftClick model =
     case ClickPoints.getClickPositionFromMouse model of
-      SOME (hIdx, vIdx) => addCoordinates (model, hIdx, vIdx)
+      SOME (hIdx, vIdx) => addPixel (model, hIdx, vIdx)
     | NONE => (model, [])
 
   fun enterOrSpaceCoordinates model =
     let val {arrowX, arrowY, ...} = model
-    in addCoordinates (model, arrowX, arrowY)
+    in addPixel (model, arrowX, arrowY)
     end
 
-  fun deletePixel (model, hIdx, vIdx) =
-    changeSquare (model, hIdx, vIdx, AppWith.deleteSquare)
-
   fun backspace model =
     let val {arrowX, arrowY, ...} = model
     in deletePixel (model, arrowX, arrowY)