Implement String.Chars for Shapes. W00T.

lib/string/chars/vivid/shape.ex

@@ -0,0 +1,25 @@
+defmodule Vivid.ShapeToString do
+  alias Vivid.{Bounds, Frame, Transform, RGBA}
+
+  def to_string(shape) do
+    bounds = Bounds.bounds(shape)
+    width  = Bounds.width(bounds) + 3 |> round
+    height = Bounds.height(bounds) + 3 |> round
+    frame = Frame.init(width, height, RGBA.white)
+
+    shape = shape
+      |> Transform.center(frame)
+      |> Transform.apply
+
+    frame
+    |> Frame.push(shape, RGBA.black)
+    |> Kernel.to_string
+  end
+end
+
+Enum.each(~w(Arc Box Circle Group Line Path Polygon), fn mod ->
+  mod = Module.concat(Vivid, mod)
+  defimpl String.Chars, for: mod do
+    def to_string(shape), do: Vivid.ShapeToString.to_string(shape)
+  end
+end)

lib/vivid/rasterize/line.ex

@@ -57,7 +57,9 @@ defimpl Vivid.Rasterize, for: Vivid.Line do
 
       reduce_points(points, steps, current_x, current_y, x_increment, y_increment)
     end
+    |> pixel_round
     |> clip(bounds)
+    |> Enum.into(MapSet.new)
   end
 
   defp reduce_points(points, 0, _, _, _, _), do: points
@@ -73,10 +75,14 @@ defimpl Vivid.Rasterize, for: Vivid.Line do
   defp choose_largest_of(a, b) when a > b, do: a
   defp choose_largest_of(_, b), do: b
 
+  defp pixel_round(points) do
+    points
+    |> Stream.map(&Point.round(&1))
+  end
+
   defp clip(points, %Bounds{}=bounds) do
     points
     |> Stream.filter(&Bounds.contains?(bounds,&1))
-    |> Enum.into(MapSet.new)
   end
 
 end