/// <summary>
/// Trims all mods from a given <see cref="Mod"/> array which do not adjust difficulty.
/// This is used to match osu!stable/osu!web calculations for the time being, until such a point that these mods do get considered.
/// </summary>
public static Mod[] TrimNonDifficultyAdjustmentMods(Ruleset ruleset, Mod[] mods)
{
var beatmap = new EmptyWorkingBeatmap
{
BeatmapInfo =
{
Ruleset = ruleset.RulesetInfo,
BaseDifficulty = new BeatmapDifficulty()
}
};
var difficultyAdjustmentMods = ModUtils.FlattenMods(
ruleset.CreateDifficultyCalculator(beatmap).CreateDifficultyAdjustmentModCombinations())
.Select(m => m.GetType())
.Distinct()
.ToHashSet();
// Special case for DT/NC.
if (mods.Any(m => m is ModDoubleTime))
{
difficultyAdjustmentMods.Add(ruleset.GetAllMods().Single(m => m is ModNightcore).GetType());
}
return(mods.Where(m => difficultyAdjustmentMods.Contains(m.GetType())).ToArray());
}
/// <summary>
/// Transforms a given <see cref="Mod"/> combination into one which is applicable to legacy scores.
/// This is used to match osu!stable/osu!web calculations for the time being, until such a point that these mods do get considered.
/// </summary>
public static Mod[] ConvertToLegacyDifficultyAdjustmentMods(Ruleset ruleset, Mod[] mods)
{
var beatmap = new EmptyWorkingBeatmap
{
BeatmapInfo =
{
Ruleset = ruleset.RulesetInfo,
Difficulty = new BeatmapDifficulty()
}
};
var allMods = ruleset.CreateAllMods().ToArray();
var allowedMods = ModUtils.FlattenMods(
ruleset.CreateDifficultyCalculator(beatmap).CreateDifficultyAdjustmentModCombinations())
.Select(m => m.GetType())
.Distinct()
.ToHashSet();
// Special case to allow either DT or NC.
if (mods.Any(m => m is ModDoubleTime))
{
allowedMods.Add(allMods.Single(m => m is ModNightcore).GetType());
}
var result = new List <Mod>();
var classicMod = allMods.SingleOrDefault(m => m is ModClassic);
if (classicMod != null)
{
result.Add(classicMod);
}
result.AddRange(mods.Where(m => allowedMods.Contains(m.GetType())));
return(result.ToArray());
}