Fix regressions with HitRenderers, while also cleaning them up.

osu.Game/Beatmaps/Objects/Catch/CatchConverter.cs

@@ -0,0 +1,43 @@
+//Copyright (c) 2007-2016 ppy Pty Ltd <contact@ppy.sh>.
+//Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using osu.Game.Beatmaps.Objects.Catch;
+using osu.Game.Beatmaps.Objects.Osu;
+
+namespace osu.Game.Beatmaps.Objects.Catch
+{
+    class CatchConverter : HitObjectConverter<CatchBaseHit>
+    {
+        public override List<CatchBaseHit> Convert(List<HitObject> input)
+        {
+            List<CatchBaseHit> output = new List<CatchBaseHit>();
+
+            foreach (HitObject i in input)
+            {
+                CatchBaseHit h = i as CatchBaseHit;
+
+                if (h == null)
+                {
+                    OsuBaseHit o = i as OsuBaseHit;
+
+                    if (o == null) throw new Exception(@"Can't convert!");
+
+                    h = new Fruit
+                    {
+                        StartTime = o.StartTime,
+                        Position = o.Position.X,
+                    };
+                }
+
+                output.Add(h);
+            }
+
+            return output;
+        }
+    }
+}