Merge branch 'master' into modselect-disable-stacking

osu.Game.Tests/Mods/ModUtilsTest.cs

@@ -1,9 +1,12 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System;
+using System.Linq;
 using Moq;
 using NUnit.Framework;
 using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Osu.Mods;
 using osu.Game.Utils;
 
 namespace osu.Game.Tests.Mods
@@ -99,6 +102,53 @@ namespace osu.Game.Tests.Mods
             Assert.That(ModUtils.CheckAllowed(new[] { mod.Object }, new[] { typeof(Mod) }), Is.False);
         }
 
+        private static readonly object[] invalid_mod_test_scenarios =
+        {
+            // incompatible pair.
+            new object[]
+            {
+                new Mod[] { new OsuModDoubleTime(), new OsuModHalfTime() },
+                new[] { typeof(OsuModDoubleTime), typeof(OsuModHalfTime) }
+            },
+            // incompatible pair with derived class.
+            new object[]
+            {
+                new Mod[] { new OsuModNightcore(), new OsuModHalfTime() },
+                new[] { typeof(OsuModNightcore), typeof(OsuModHalfTime) }
+            },
+            // system mod.
+            new object[]
+            {
+                new Mod[] { new OsuModDoubleTime(), new OsuModTouchDevice() },
+                new[] { typeof(OsuModTouchDevice) }
+            },
+            // multi mod.
+            new object[]
+            {
+                new Mod[] { new MultiMod(new OsuModHalfTime()), new OsuModHalfTime() },
+                new[] { typeof(MultiMod) }
+            },
+            // valid pair.
+            new object[]
+            {
+                new Mod[] { new OsuModDoubleTime(), new OsuModHardRock() },
+                null
+            }
+        };
+
+        [TestCaseSource(nameof(invalid_mod_test_scenarios))]
+        public void TestInvalidModScenarios(Mod[] inputMods, Type[] expectedInvalid)
+        {
+            bool isValid = ModUtils.CheckValidForGameplay(inputMods, out var invalid);
+
+            Assert.That(isValid, Is.EqualTo(expectedInvalid == null));
+
+            if (isValid)
+                Assert.IsNull(invalid);
+            else
+                Assert.That(invalid?.Select(t => t.GetType()), Is.EquivalentTo(expectedInvalid));
+        }
+
         public abstract class CustomMod1 : Mod
         {
         }

osu.Game/OsuGame.cs

@@ -468,6 +468,12 @@ namespace osu.Game
         private void modsChanged(ValueChangedEvent<IReadOnlyList<Mod>> mods)
         {
             updateModDefaults();
+
+            if (!ModUtils.CheckValidForGameplay(mods.NewValue, out var invalid))
+            {
+                // ensure we always have a valid set of mods.
+                SelectedMods.Value = mods.NewValue.Except(invalid).ToArray();
+            }
         }
 
         private void updateModDefaults()

osu.Game/Utils/ModUtils.cs

@@ -83,6 +83,30 @@ namespace osu.Game.Utils
                               .All(m => allowedSet.Contains(m.GetType()));
         }
 
+        /// <summary>
+        /// Check the provided combination of mods are valid for a local gameplay session.
+        /// </summary>
+        /// <param name="mods">The mods to check.</param>
+        /// <param name="invalidMods">Invalid mods, if any were found. Can be null if all mods were valid.</param>
+        /// <returns>Whether the input mods were all valid. If false, <paramref name="invalidMods"/> will contain all invalid entries.</returns>
+        public static bool CheckValidForGameplay(IEnumerable<Mod> mods, out List<Mod>? invalidMods)
+        {
+            mods = mods.ToArray();
+
+            CheckCompatibleSet(mods, out invalidMods);
+
+            foreach (var mod in mods)
+            {
+                if (mod.Type == ModType.System || !mod.HasImplementation || mod is MultiMod)
+                {
+                    invalidMods ??= new List<Mod>();
+                    invalidMods.Add(mod);
+                }
+            }
+
+            return invalidMods == null;
+        }
+
         /// <summary>
         /// Flattens a set of <see cref="Mod"/>s, returning a new set with all <see cref="MultiMod"/>s removed.
         /// </summary>