Add 'dotscape/' from commit 'f306501a68a51b634e895c5fdac70788ae899d75'

git-subtree-dir: dotscape
git-subtree-mainline: 6b91d64fc3
git-subtree-split: f306501a68

dotscape/fcore/parser/parse-grid.sml

@@ -0,0 +1,36 @@
+structure ParseGrid =
+struct
+  fun make (canvasWidth, canvasHeight) =
+    let
+      val maxPoints = Int.max (canvasWidth, canvasHeight)
+      val emptyYAxis = Vector.tabulate (maxPoints, fn _ =>
+        {r = 0, g = 0, b = 0, a = 0})
+    in
+      Vector.tabulate (maxPoints, fn _ => emptyYAxis)
+    end
+
+  local
+    fun loopY (yAxis, x, ex, y, ey, colour) =
+      if y > ey orelse y >= Vector.length yAxis then
+        yAxis
+      else
+        let val yAxis = Vector.update (yAxis, y, colour)
+        in loopY (yAxis, x, ex, y + 1, ey, colour)
+        end
+
+    fun loopX (grid, x, ex, y, ey, colour) =
+      if x > ex orelse x >= Vector.length grid then
+        grid
+      else
+        let
+          val yAxis = Vector.sub (grid, x)
+          val yAxis = loopY (yAxis, x, ex, y, ey, colour)
+          val grid = Vector.update (grid, x, yAxis)
+        in
+          loopX (grid, x + 1, ex, y, ey, colour)
+        end
+  in
+    fun applyItem (grid, x, y, ex, ey, colour) =
+      loopX (grid, x, ex, y, ey, colour)
+  end
+end