improve graph lines

fcore/quad-tree.sml

@@ -236,36 +236,43 @@ struct
     end
 
   local
-    fun loop (windowWidth, windowHeight, squares, acc) =
+    fun loop (windowWidth, windowHeight, squares, acc, canvasWidth,
+      canvasHeight, xClickPoints, yClickPoints) =
       case squares of
         {x, y, ex, ey, data = _} :: tl =>
           let
-            val x = Real32.fromInt x
-            val y = Real32.fromInt y
-            val ex = Real32.fromInt ex
-            val ey = Real32.fromInt ey
+            val ex = if ex = x then x + 1 else ex
+            val ey = if ey = y then y + 1 else ey
+
+            val x = Vector.sub (xClickPoints, x)
+            val ex = Vector.sub (xClickPoints, ex)
+            val y = Vector.sub (yClickPoints, y)
+            val ey = Vector.sub (yClickPoints, ey)
 
             val startX = Ndc.fromPixelX (x, windowWidth, windowHeight)
-            val endX = Ndc.fromPixelX (ex, windowWidth, windowHeight)
+            val endX = Ndc.fromPixelX (ex , windowWidth, windowHeight)
             val startY = Ndc.fromPixelY (y, windowWidth, windowHeight)
-            val endY = Ndc.fromPixelY (ey, windowWidth, windowHeight)
+            val endY = Ndc.fromPixelY (ey , windowWidth, windowHeight)
 
             val vec = 
               Ndc.ltrbToVertexRgb (startX, startY, endX, endY, 0.0, 0.0, 0.0)
             val acc = vec :: acc
           in
-            loop (windowWidth, windowHeight, tl, acc)
+            loop (windowWidth, windowHeight, tl, acc, canvasWidth, canvasHeight,
+            xClickPoints, yClickPoints)
           end
       | [] => Vector.concat acc
   in
-    fun toTriangles (windowWidth, windowHeight, squares, size) =
+    fun toTriangles (windowWidth, windowHeight, squares, size, canvasWidth,
+      canvasHeight, xClickPoints, yClickPoints) =
       let
         val qtree = build (0, 0, size, squares)
         val squares = toList qtree
         val msg = List.length squares
         val () = print (Int.toString msg ^ "\n")
       in
-        loop (windowWidth, windowHeight, squares, [])
+        loop (windowWidth, windowHeight, squares, [], canvasWidth, canvasHeight,
+        xClickPoints, yClickPoints)
       end
   end
 end