Add Chroma keying to the background of the showcase video.

osu.Game.Tournament/Screens/Showcase/ShowcaseScreen.cs

@@ -4,11 +4,14 @@
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Game.Tournament.Components;
+using osu.Framework.Graphics.Shapes;
+using osuTK.Graphics;
 
 namespace osu.Game.Tournament.Screens.Showcase
 {
-    public class ShowcaseScreen : BeatmapInfoScreen
+    public class ShowcaseScreen : BeatmapInfoScreen, IProvideVideo
     {
+        private Box chroma;
         [BackgroundDependencyLoader]
         private void load()
         {
@@ -18,6 +21,16 @@ namespace osu.Game.Tournament.Screens.Showcase
                 {
                     Loop = true,
                     RelativeSizeAxes = Axes.Both,
+                },
+                chroma = new Box
+                        {
+                            // chroma key area for stable gameplay
+                            Name = "chroma",
+                            Anchor = Anchor.TopCentre,
+                            Origin = Anchor.TopCentre,
+                            Height = 695,
+                            Width = 1366,
+                            Colour = new Color4(0, 255, 0, 255),
                 }
             });
         }