Allow beatmap conversion from non-std rulesets

Templates/Rulesets/ruleset-scrolling-example/osu.Game.Rulesets.Pippidon/Beatmaps/PippidonBeatmapConverter.cs

@@ -28,7 +28,7 @@ public PippidonBeatmapConverter(IBeatmap beatmap, Ruleset ruleset)
             }
         }
 
-        public override bool CanConvert() => Beatmap.HitObjects.All(h => h is IHasXPosition && h is IHasYPosition);
+        public override bool CanConvert() => Beatmap.HitObjects.All(h => h is IHasXPosition || h is IHasYPosition);
 
         protected override IEnumerable<PippidonHitObject> ConvertHitObject(HitObject original, IBeatmap beatmap, CancellationToken cancellationToken)
         {
@@ -43,6 +43,6 @@ protected override IEnumerable<PippidonHitObject> ConvertHitObject(HitObject ori
         private int getLane(HitObject hitObject) => (int)Math.Clamp(
             (getUsablePosition(hitObject) - minPosition) / (maxPosition - minPosition) * PippidonPlayfield.LANE_COUNT, 0, PippidonPlayfield.LANE_COUNT - 1);
 
-        private float getUsablePosition(HitObject h) => (h as IHasYPosition)?.Y ?? ((IHasXPosition)h).X;
+        private float getUsablePosition(HitObject h) => (h as IHasXPosition)?.X ?? ((IHasYPosition)h).Y;
     }
 }

Templates/Rulesets/ruleset-scrolling-example/osu.Game.Rulesets.Pippidon/Beatmaps/PippidonRulesetConversionSupport.cs

@@ -0,0 +1,19 @@
+// Copyright (c) ppy Pty Ltd <[email protected]>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Game.Rulesets.Filter;
+
+namespace osu.Game.Rulesets.Pippidon.Beatmaps
+{
+    public class PippidonRulesetConversionSupport : IRulesetConvertSupport
+    {
+        public bool CanBePlayed(RulesetInfo ruleset, bool conversionEnabled)
+        {
+            // Always show ctb maps even without converts, since extensive playtesting has shown that the maps match
+            // pippidon very well and we also don't have many maps to start out with yet.
+            // Show std only when converts are enabled
+            return ruleset.ShortName == "pippidon" || ruleset.ShortName == "fruits" ||
+                   (conversionEnabled && ruleset.ShortName == "osu");
+        }
+    }
+}

Templates/Rulesets/ruleset-scrolling-example/osu.Game.Rulesets.Pippidon/PippidonRuleset.cs

@@ -7,6 +7,7 @@
 using osu.Framework.Input.Bindings;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Difficulty;
+using osu.Game.Rulesets.Filter;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Pippidon.Beatmaps;
 using osu.Game.Rulesets.Pippidon.Mods;
@@ -37,6 +38,8 @@ public override IEnumerable<Mod> GetModsFor(ModType type)
             }
         }
 
+        public override IRulesetConvertSupport GetRulesetMapConvertSupport() => new PippidonRulesetConversionSupport();
+
         public override string ShortName => "pippidon";
 
         public override IEnumerable<KeyBinding> GetDefaultKeyBindings(int variant = 0) => new[]

osu.Game.Tests/NonVisual/Filtering/FilterMatchingTest.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Collections.Generic;
+using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Bindables;
 using osu.Game.Beatmaps;
@@ -99,6 +100,59 @@ public void TestCriteriaMatchingConvertedBeatmapsForCustomRulesets()
             Assert.IsFalse(carouselItem.Filtered.Value);
         }
 
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void TestCriteriaMatchingCustomConvertRules(bool convertsStd)
+        {
+            var exampleBeatmapInfo = getExampleBeatmap();
+            var criteria = new FilterCriteria
+            {
+                Ruleset = new RulesetInfo { OnlineID = -1, ShortName = "custom" },
+                AllowConvertedBeatmaps = true,
+                RulesetConvertSupport = new CustomConvertSupport(["custom"], convertsStd ? ["osu"] : [])
+            };
+            var carouselItem = new CarouselBeatmap(exampleBeatmapInfo);
+            carouselItem.Filter(criteria);
+            Assert.AreEqual(!convertsStd, carouselItem.Filtered.Value);
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void TestCriteriaMatchingCustomNativeConvertRules(bool allowConverts)
+        {
+            var exampleBeatmapInfo = getExampleBeatmap();
+            var criteria = new FilterCriteria
+            {
+                Ruleset = new RulesetInfo { OnlineID = -1, ShortName = "custom" },
+                AllowConvertedBeatmaps = allowConverts,
+                RulesetConvertSupport = new CustomConvertSupport(["custom", "osu"], [])
+            };
+            var carouselItem = new CarouselBeatmap(exampleBeatmapInfo);
+            carouselItem.Filter(criteria);
+            Assert.IsFalse(carouselItem.Filtered.Value);
+        }
+
+        private class CustomConvertSupport : IRulesetConvertSupport
+        {
+            private readonly string[] nativeFormats, convertFormats;
+
+            public CustomConvertSupport(string[] nativeFormats, string[] convertFormats)
+            {
+                this.nativeFormats = nativeFormats;
+                this.convertFormats = convertFormats;
+            }
+
+            public bool CanBePlayed(RulesetInfo ruleset, bool conversionEnabled)
+            {
+                if (conversionEnabled && convertFormats.Contains(ruleset.ShortName))
+                    return true;
+
+                return nativeFormats.Contains(ruleset.ShortName);
+            }
+        }
+
         [Test]
         [TestCase(true)]
         [TestCase(false)]

osu.Game/Rulesets/Filter/IRulesetConvertSupport.cs

@@ -0,0 +1,26 @@
+// Copyright (c) ppy Pty Ltd <[email protected]>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Game.Screens.Select;
+
+namespace osu.Game.Rulesets.Filter
+{
+    /// <summary>
+    /// Allows for changing which beatmap rulesets are displayed in song select (as implemented in <see cref="FilterCriteria"/>)
+    /// with ruleset-specific criteria.
+    /// </summary>
+    public interface IRulesetConvertSupport
+    {
+        /// <summary>
+        /// Checks whether maps from the supplied <paramref name="ruleset"/> may be played with this ruleset with or
+        /// without beatmap conversion enabled.
+        /// </summary>
+        /// <param name="ruleset">The foreign ruleset to check if it may be played.</param>
+        /// <param name="conversionEnabled">Indicates if the player wants converts or not.</param>
+        /// <returns>
+        /// <c>true</c> if the beatmap can be played and should be shown in the beatmap list,
+        /// <c>false</c> otherwise.
+        /// </returns>
+        bool CanBePlayed(RulesetInfo ruleset, bool conversionEnabled);
+    }
+}

osu.Game/Rulesets/Ruleset.cs

@@ -395,6 +395,13 @@ protected Ruleset()
         /// </summary>
         public virtual IRulesetFilterCriteria? CreateRulesetFilterCriteria() => null;
 
+        /// <summary>
+        /// Creates ruleset-specific conversion support, used in filtering which beatmaps to show based on selected ruleset.
+        /// This interface describes which maps from other rulesets may be used without beatmap conversion enabled and which ones may be used when beatmap conversion is enabled.
+        /// If not set, osu treats this ruleset as the only native format and osu standard as only ruleset that maps can be converted from.
+        /// </summary>
+        public virtual IRulesetConvertSupport? GetRulesetMapConvertSupport() => null;
+
         /// <summary>
         /// Can be overridden to add ruleset-specific sections to the editor beatmap setup screen.
         /// </summary>

osu.Game/Screens/Select/Carousel/CarouselBeatmap.cs

@@ -33,8 +33,10 @@ private bool checkMatch(FilterCriteria criteria)
         {
             bool match =
                 criteria.Ruleset == null ||
-                BeatmapInfo.Ruleset.ShortName == criteria.Ruleset.ShortName ||
-                (BeatmapInfo.Ruleset.OnlineID == 0 && criteria.Ruleset.OnlineID != 0 && criteria.AllowConvertedBeatmaps);
+                (criteria.RulesetConvertSupport?.CanBePlayed(BeatmapInfo.Ruleset, criteria.AllowConvertedBeatmaps) ??
+                 (BeatmapInfo.Ruleset.ShortName == criteria.Ruleset.ShortName ||
+                  (BeatmapInfo.Ruleset.OnlineID == 0 && criteria.Ruleset.OnlineID != 0 &&
+                   criteria.AllowConvertedBeatmaps)));
 
             if (BeatmapInfo.BeatmapSet?.Equals(criteria.SelectedBeatmapSet) == true)
             {

osu.Game/Screens/Select/FilterControl.cs

@@ -77,7 +77,9 @@ public virtual FilterCriteria CreateCriteria()
             if (!maximumStars.IsDefault)
                 criteria.UserStarDifficulty.Max = maximumStars.Value;
 
-            criteria.RulesetCriteria = ruleset.Value.CreateInstance().CreateRulesetFilterCriteria();
+            var rulesetInstance = ruleset.Value.CreateInstance();
+            criteria.RulesetCriteria = rulesetInstance.CreateRulesetFilterCriteria();
+            criteria.RulesetConvertSupport = rulesetInstance.GetRulesetMapConvertSupport();
 
             FilterQueryParser.ApplyQueries(criteria, query);
             return criteria;

osu.Game/Screens/Select/FilterCriteria.cs

@@ -122,6 +122,12 @@ public string SearchText
 
         public IRulesetFilterCriteria? RulesetCriteria { get; set; }
 
+        /// <summary>
+        /// If set, overrides which maps can be played and should be shown, instead of only showing maps from our own
+        /// ruleset and std with map conversion enabled.
+        /// </summary>
+        public IRulesetConvertSupport? RulesetConvertSupport { get; set; }
+
         public readonly struct OptionalSet<T> : IEquatable<OptionalSet<T>>
             where T : struct, Enum
         {