Add reversing capability to ScrollingPlayfield.

osu.Desktop.Tests/Visual/TestCaseScrollingPlayfield.cs

@@ -24,6 +24,8 @@ namespace osu.Desktop.Tests.Visual
     /// </summary>
     public class TestCaseScrollingPlayfield : OsuTestCase
     {
+        private readonly TestHitRenderer hitRenderer;
+
         public TestCaseScrollingPlayfield()
         {
             Clock = new FramedClock();
@@ -50,7 +52,9 @@ namespace osu.Desktop.Tests.Visual
 
             WorkingBeatmap beatmap = new TestWorkingBeatmap(b);
 
-            Add(new TestHitRenderer(beatmap, true));
+            Add(hitRenderer = new TestHitRenderer(beatmap, true));
+
+            AddStep("Reverse direction", () => hitRenderer.Playfield.Reversed.Value = !hitRenderer.Playfield.Reversed);
         }
 
         private class TestHitRenderer : ScrollingHitRenderer<TestPlayfield, TestHitObject, TestJudgement>
@@ -60,6 +64,8 @@ namespace osu.Desktop.Tests.Visual
             {
             }
 
+            public new TestPlayfield Playfield => base.Playfield;
+
             public override ScoreProcessor CreateScoreProcessor() => new TestScoreProcessor();
 
             protected override BeatmapConverter<TestHitObject> CreateBeatmapConverter() => new TestBeatmapConverter();

osu.Game.Rulesets.Mania/UI/ManiaPlayfield.cs

@@ -124,7 +124,9 @@ namespace osu.Game.Rulesets.Mania.UI
 
             for (int i = 0; i < columnCount; i++)
             {
-                var c = new Column { VisibleTimeRange = VisibleTimeRange };
+                var c = new Column();
+                c.VisibleTimeRange.BindTo(VisibleTimeRange);
+
                 columns.Add(c);
                 AddNested(c);
             }

osu.Game/Rulesets/Timing/SpeedAdjustmentContainer.cs

@@ -26,6 +26,16 @@ namespace osu.Game.Rulesets.Timing
             set { visibleTimeRange.BindTo(value); }
         }
 
+        private readonly BindableBool reversed = new BindableBool();
+        /// <summary>
+        /// Whether to reverse the scrolling direction is reversed.
+        /// </summary>
+        public BindableBool Reversed
+        {
+            get { return reversed; }
+            set { reversed.BindTo(value); }
+        }
+
         protected override Container<DrawableHitObject> Content => content;
         private Container<DrawableHitObject> content;
 
@@ -70,7 +80,14 @@ namespace osu.Game.Rulesets.Timing
 
             // The speed adjustment happens by modifying our size by the multiplier while maintaining the visible time range as the relatve size for our children
             Size = new Vector2((ScrollingAxes & Axes.X) > 0 ? multiplier : 1, (ScrollingAxes & Axes.Y) > 0 ? multiplier : 1);
-            RelativeChildSize = new Vector2((ScrollingAxes & Axes.X) > 0 ? (float)VisibleTimeRange : 1, (ScrollingAxes & Axes.Y) > 0 ? (float)VisibleTimeRange : 1);
+
+            if (Reversed)
+            {
+                RelativeChildSize = new Vector2((ScrollingAxes & Axes.X) > 0 ? (float)-VisibleTimeRange : 1, (ScrollingAxes & Axes.Y) > 0 ? (float)-VisibleTimeRange : 1);
+                RelativeChildOffset = new Vector2((ScrollingAxes & Axes.X) > 0 ? (float)VisibleTimeRange : 0, (ScrollingAxes & Axes.Y) > 0 ? (float)VisibleTimeRange : 0);
+            }
+            else
+                RelativeChildSize = new Vector2((ScrollingAxes & Axes.X) > 0 ? (float)VisibleTimeRange : 1, (ScrollingAxes & Axes.Y) > 0 ? (float)VisibleTimeRange : 1);
         }
 
         public override double LifetimeStart => ControlPoint.StartTime - VisibleTimeRange;

osu.Game/Rulesets/UI/ScrollingPlayfield.cs

@@ -44,10 +44,10 @@ namespace osu.Game.Rulesets.UI
         private const double time_span_step = 50;
 
         /// <summary>
-        /// Gets or sets the range of time that is visible by the length of the scrolling axes.
+        /// The span of time that is visible by the length of the scrolling axes.
         /// For example, only hit objects with start time less than or equal to 1000 will be visible with <see cref="VisibleTimeRange"/> = 1000.
         /// </summary>
-        private readonly BindableDouble visibleTimeRange = new BindableDouble(time_span_default)
+        public readonly BindableDouble VisibleTimeRange = new BindableDouble(time_span_default)
         {
             Default = time_span_default,
             MinValue = time_span_min,
@@ -55,14 +55,9 @@ namespace osu.Game.Rulesets.UI
         };
 
         /// <summary>
-        /// The span of time visible by the length of the scrolling axes.
+        /// Whether to reverse the scrolling direction is reversed.
         /// </summary>
-        /// <returns></returns>
+        public readonly BindableBool Reversed = new BindableBool();
-        public BindableDouble VisibleTimeRange
-        {
-            get { return visibleTimeRange; }
-            set { visibleTimeRange.BindTo(value); }
-        }
 
         /// <summary>
         /// The container that contains the <see cref="SpeedAdjustmentContainer"/>s and <see cref="DrawableHitObject"/>s.
@@ -80,7 +75,8 @@ namespace osu.Game.Rulesets.UI
             base.HitObjects = HitObjects = new ScrollingHitObjectContainer(scrollingAxes)
             {
                 RelativeSizeAxes = Axes.Both,
-                VisibleTimeRange = VisibleTimeRange
+                VisibleTimeRange = VisibleTimeRange,
+                Reversed = Reversed
             };
         }
 
@@ -158,6 +154,16 @@ namespace osu.Game.Rulesets.UI
                 set { visibleTimeRange.BindTo(value); }
             }
 
+            private readonly BindableBool reversed = new BindableBool();
+            /// <summary>
+            /// Whether to reverse the scrolling direction is reversed.
+            /// </summary>
+            public BindableBool Reversed
+            {
+                get { return reversed; }
+                set { reversed.BindTo(value); }
+            }
+
             protected override Container<DrawableHitObject<TObject, TJudgement>> Content => content;
             private readonly Container<DrawableHitObject<TObject, TJudgement>> content;
 
@@ -188,6 +194,7 @@ namespace osu.Game.Rulesets.UI
             {
                 speedAdjustment.VisibleTimeRange.BindTo(VisibleTimeRange);
                 speedAdjustment.ScrollingAxes = scrollingAxes;
+                speedAdjustment.Reversed = Reversed;
                 AddInternal(speedAdjustment);
             }