Add generator to generate patterns from HitObjects.

osu.Game.Rulesets.Mania/Beatmaps/ManiaBeatmapConverter.cs

@@ -11,11 +11,19 @@ using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.Mania.Beatmaps.Patterns;
 using osu.Game.Rulesets.Mania.MathUtils;
 using osu.Game.Database;
+using osu.Game.Beatmaps.Timing;
+using osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy;
+using OpenTK;
 
 namespace osu.Game.Rulesets.Mania.Beatmaps
 {
     public class ManiaBeatmapConverter : BeatmapConverter<ManiaHitObject>
     {
+        /// <summary>
+        /// Maximum number of previous notes to consider for density calculation.
+        /// </summary>
+        private const int max_notes_for_density = 7;
+
         protected override IEnumerable<Type> ValidConversionTypes { get; } = new[] { typeof(IHasXPosition) };
 
         private Pattern lastPattern = new Pattern();
@@ -55,6 +63,26 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
                 yield return obj;
         }
 
+        private List<double> prevNoteTimes = new List<double>(max_notes_for_density);
+        private double density = int.MaxValue;
+        private void computeDensity(double newNoteTime)
+        {
+            if (prevNoteTimes.Count == max_notes_for_density)
+                prevNoteTimes.RemoveAt(0);
+            prevNoteTimes.Add(newNoteTime);
+
+            density = (prevNoteTimes[prevNoteTimes.Count - 1] - prevNoteTimes[0]) / prevNoteTimes.Count;
+        }
+
+        private double lastTime;
+        private Vector2 lastPosition;
+        private PatternType lastStair;
+        private void recordNote(double time, Vector2 position)
+        {
+            lastTime = time;
+            lastPosition = position;
+        }
+
         /// <summary>
         /// Method that generates hit objects for osu!mania specific beatmaps.
         /// </summary>
@@ -83,7 +111,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
 
             // Following lines currently commented out to appease resharper
 
-            //Patterns.PatternGenerator conversion = null;
+            Patterns.PatternGenerator conversion = null;
 
             if (distanceData != null)
             {
@@ -95,16 +123,24 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
             }
             else if (positionData != null)
             {
-                // Circle
+                computeDensity(original.StartTime);
+
+                conversion = new HitObjectPatternGenerator(random, original, beatmap, lastPattern, lastTime, lastPosition, density, lastStair);
+
+                recordNote(original.StartTime, positionData.Position);
             }
 
-            //if (conversion == null)
+            if (conversion == null)
-            return null;
+                return null;
 
-            //Pattern newPattern = conversion.Generate();
+            Pattern newPattern = conversion.Generate();
-            //lastPattern = newPattern;
+            lastPattern = newPattern;
 
-            //return newPattern.HitObjects;
+            var stairPatternGenerator = conversion as HitObjectPatternGenerator;
+            if (stairPatternGenerator != null)
+                lastStair = stairPatternGenerator.StairType;
+
+            return newPattern.HitObjects;
         }
 
         /// <summary>

osu.Game.Rulesets.Mania/Beatmaps/Patterns/Legacy/HitObjectPatternGenerator.cs

@@ -0,0 +1,425 @@
+// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using System;
+using System.Linq;
+using OpenTK;
+using osu.Game.Audio;
+using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.Timing;
+using osu.Game.Rulesets.Mania.MathUtils;
+using osu.Game.Rulesets.Mania.Objects;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Types;
+
+namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
+{
+    internal class HitObjectPatternGenerator : PatternGenerator
+    {
+        public PatternType StairType { get; private set; }
+
+        private readonly PatternType convertType;
+
+        public HitObjectPatternGenerator(FastRandom random, HitObject hitObject, Beatmap beatmap, Pattern previousPattern, double previousTime, Vector2 previousPosition, double density, PatternType lastStair)
+            : base(random, hitObject, beatmap, previousPattern)
+        {
+            StairType = lastStair;
+
+            ControlPoint overridePoint;
+            ControlPoint controlPoint = beatmap.TimingInfo.TimingPointAt(hitObject.StartTime, out overridePoint);
+
+            var positionData = hitObject as IHasPosition;
+
+            float positionSeparation = ((positionData?.Position ?? Vector2.Zero) - previousPosition).Length;
+            double timeSeparation = hitObject.StartTime - previousTime;
+
+            double beatLength = controlPoint.BeatLength;
+            bool kiai = (overridePoint ?? controlPoint).KiaiMode;
+
+            if (timeSeparation <= 125)
+            {
+                // More than 120 BPM
+                convertType |= PatternType.ForceNotStack;
+            }
+
+            if (timeSeparation <= 80)
+            {
+                // More than 187 BPM
+                convertType |= PatternType.ForceNotStack | PatternType.KeepSingle;
+            }
+            else if (timeSeparation <= 95)
+            {
+                // More than 157 BPM
+                convertType |= PatternType.ForceNotStack | PatternType.KeepSingle | lastStair;
+            }
+            else if (timeSeparation <= 105)
+            {
+                // More than 140 BPM
+                convertType |= PatternType.ForceNotStack | PatternType.LowProbability;
+            }
+            else if (timeSeparation <= 125)
+            {
+                // More than 120 BPM
+                convertType |= PatternType.ForceNotStack;
+            }
+            else if (timeSeparation <= 135 && positionSeparation < 20)
+            {
+                // More than 111 BPM stream
+                convertType |= PatternType.Cycle | PatternType.KeepSingle;
+            }
+            else if (timeSeparation <= 150 & positionSeparation < 20)
+            {
+                // More than 100 BPM stream
+                convertType |= PatternType.ForceStack | PatternType.LowProbability;
+            }
+            else if (positionSeparation < 20 && density >= beatLength / 2.5)
+            {
+                // Low density stream
+                convertType |= PatternType.Reverse | PatternType.LowProbability;
+            }
+            else if (density < beatLength / 2.5 || kiai)
+            {
+                // High density
+            }
+            else
+                convertType |= PatternType.LowProbability;
+        }
+
+        public override Pattern Generate()
+        {
+            int lastColumn = PreviousPattern.HitObjects.First().Column;
+
+            if ((convertType & PatternType.Reverse) > 0 && PreviousPattern.HitObjects.Count() > 0)
+            {
+                // Generate a new pattern by copying the last hit objects in reverse-column order
+                var pattern = new Pattern();
+
+                int siblings = PreviousPattern.HitObjects.Count(h => h.Column >= RandomStart);
+
+                for (int i = RandomStart; i < AvailableColumns; i++)
+                    if (PreviousPattern.IsFilled(i))
+                        addToPattern(pattern, RandomStart + AvailableColumns - i - 1, siblings);
+
+                return pattern;
+            }
+
+            if ((convertType & PatternType.Cycle) > 0 && PreviousPattern.HitObjects.Count() == 1
+                // If we convert to 7K + 1, let's not overload the special key
+                && (AvailableColumns != 8 || lastColumn != 0)
+                // Make sure the last column was not the centre column
+                && (AvailableColumns % 2 == 0 || lastColumn != AvailableColumns / 2))
+            {
+                // Generate a new pattern by cycling backwards (similar to Reverse but for only one hit object)
+                var pattern = new Pattern();
+
+                int column = RandomStart + AvailableColumns - lastColumn - 1;
+                addToPattern(pattern, column);
+
+                return pattern;
+            }
+
+            if ((convertType & PatternType.ForceStack) > 0 && PreviousPattern.HitObjects.Count() > 0)
+            {
+                // Generate a new pattern by placing on the already filled columns
+                var pattern = new Pattern();
+
+                int siblings = PreviousPattern.HitObjects.Count(h => h.Column >= RandomStart);
+
+                for (int i = RandomStart; i < AvailableColumns; i++)
+                    if (PreviousPattern.IsFilled(i))
+                        addToPattern(pattern, i, siblings);
+
+                return pattern;
+            }
+
+            if ((convertType & PatternType.Stair) > 0 && PreviousPattern.HitObjects.Count() == 1)
+            {
+                // Generate a new pattern by placing on the next column, cycling back to the start if there is no "next"
+                var pattern = new Pattern();
+
+                int targetColumn = lastColumn + 1;
+                if (targetColumn == AvailableColumns)
+                {
+                    targetColumn = RandomStart;
+                    StairType = PatternType.ReverseStair;
+                }
+
+                addToPattern(pattern, targetColumn, 1);
+                return pattern;
+            }
+
+            if ((convertType & PatternType.ReverseStair) > 0 && PreviousPattern.HitObjects.Count() == 1)
+            {
+                // Generate a new pattern by placing on the previous column, cycling back to the end if there is no "previous"
+                var pattern = new Pattern();
+
+                int targetColumn = lastColumn - 1;
+                if (targetColumn == RandomStart - 1)
+                {
+                    targetColumn = AvailableColumns - 1;
+                    StairType = PatternType.Stair;
+                }
+
+                addToPattern(pattern, targetColumn, 1);
+                return pattern;
+            }
+
+            if ((convertType & PatternType.KeepSingle) > 0)
+                return generateRandomNotes(1);
+
+            if ((convertType & PatternType.Mirror) > 0)
+            {
+                if (ConversionDifficulty > 6.5)
+                    return generateRandomPatternWithMirrored(0.12, 0.38, 0.12);
+                if (ConversionDifficulty > 4)
+                    return generateRandomPatternWithMirrored(0.12, 0.17, 0);
+                return generateRandomPatternWithMirrored(0.12, 0, 0);
+            }
+
+            if (ConversionDifficulty > 6.5)
+            {
+                if ((convertType & PatternType.LowProbability) > 0)
+                    return generateRandomPattern(0.78, 0.42, 0, 0);
+                return generateRandomPattern(1, 0.62, 0, 0);
+            }
+
+            if (ConversionDifficulty > 4)
+            {
+                if ((convertType & PatternType.LowProbability) > 0)
+                    return generateRandomPattern(0.35, 0.08, 0, 0);
+                return generateRandomPattern(0.52, 0.15, 0, 0);
+            }
+
+            if (ConversionDifficulty > 2)
+            {
+                if ((convertType & PatternType.LowProbability) > 0)
+                    return generateRandomPattern(0.18, 0, 0, 0);
+                return generateRandomPattern(0.45, 0, 0, 0);
+            }
+
+            return generateRandomPattern(0, 0, 0, 0);
+        }
+
+        /// <summary>
+        /// Generates random notes.
+        /// <para>
+        /// This will generate as many as it can up to <paramref name="noteCount"/>, accounting for
+        /// any stacks if <see cref="convertType"/> is forcing no stacks.
+        /// </para>
+        /// </summary>
+        /// <param name="noteCount">The amount of notes to generate.</param>
+        /// <param name="siblingsOverride">Custom siblings count if <paramref name="noteCount"/> is not the number of siblings in this pattern.</param>
+        /// <returns>The <see cref="Pattern"/> containing the hit objects.</returns>
+        private Pattern generateRandomNotes(int noteCount, int siblingsOverride = -1)
+        {
+            var pattern = new Pattern();
+
+            bool allowStacking = (convertType & PatternType.ForceNotStack) == 0;
+
+            if (!allowStacking)
+                noteCount = Math.Min(noteCount, AvailableColumns - RandomStart - PreviousPattern.ColumnsFilled);
+
+            int nextColumn = GetColumn((HitObject as IHasXPosition)?.X ?? 0, true);
+            for (int i = 0; i < noteCount; i++)
+            {
+                while (pattern.IsFilled(nextColumn) || (PreviousPattern.IsFilled(nextColumn) && !allowStacking))
+                {
+                    if ((convertType & PatternType.Gathered) > 0)
+                    {
+                        nextColumn++;
+                        if (nextColumn == AvailableColumns)
+                            nextColumn = RandomStart;
+                    }
+                    else
+                        nextColumn = Random.Next(RandomStart, AvailableColumns);
+                }
+
+                addToPattern(pattern, nextColumn, siblingsOverride != -1 ?  siblingsOverride : noteCount);
+            }
+
+            return pattern;
+        }
+
+        /// <summary>
+        /// Whether this hit object can generate a note in the special column.
+        /// </summary>
+        private bool hasSpecialColumn() => HitObject.Samples.Any(s => s.Name == SampleInfo.HIT_CLAP) && HitObject.Samples.Any(s => s.Name == SampleInfo.HIT_FINISH);
+
+        /// <summary>
+        /// Generates a random pattern.
+        /// </summary>
+        /// <param name="p2">Probability for 2 notes to be generated.</param>
+        /// <param name="p3">Probability for 3 notes to be generated.</param>
+        /// <param name="p4">Probability for 4 notes to be generated.</param>
+        /// <param name="p5">Probability for 5 notes to be generated.</param>
+        /// <returns>The <see cref="Pattern"/> containing the hit objects.</returns>
+        private Pattern generateRandomPattern(double p2, double p3, double p4, double p5)
+        {
+            var pattern = new Pattern();
+
+            int noteCount = getRandomNoteCount(p2, p3, p4, p5);
+            int siblings = noteCount;
+
+            if (RandomStart > 0 && hasSpecialColumn(HitObject.Samples))
+            {
+                siblings++;
+                addToPattern(pattern, 0, siblings);
+            }
+
+            pattern.Add(generateRandomNotes(noteCount, siblings));
+
+            return pattern;
+        }
+
+        /// <summary>
+        /// Generates a random pattern which has both normal and mirrored notes.
+        /// </summary>
+        /// <param name="centreProbability">The probability for a note to be added to the centre column.</param>
+        /// <param name="p2">Probability for 2 notes to be generated.</param>
+        /// <param name="p3">Probability for 3 notes to be generated.</param>
+        /// <returns>The <see cref="Pattern"/> containing the hit objects.</returns>
+        private Pattern generateRandomPatternWithMirrored(double centreProbability, double p2, double p3)
+        {
+            var pattern = new Pattern();
+
+            bool addToCentre = false;
+            int noteCount = getRandomNoteCountMirrored(centreProbability, p2, p3, out addToCentre);
+            int siblings = noteCount;
+
+            if (addToCentre)
+                siblings++;
+            if (RandomStart > 0 && hasSpecialColumn(HitObject.Samples))
+                siblings++;
+
+            int columnLimit = (AvailableColumns % 2 == 0 ? AvailableColumns : AvailableColumns - 1) / 2;
+            int nextColumn = Random.Next(RandomStart, columnLimit);
+            for (int i = 0; i < noteCount; i++)
+            {
+                while (pattern.IsFilled(nextColumn))
+                    nextColumn = Random.Next(RandomStart, columnLimit);
+                // Add normal note
+                addToPattern(pattern, nextColumn, siblings);
+                // Add mirrored note
+                addToPattern(pattern, RandomStart + AvailableColumns - nextColumn - 1);
+            }
+
+            if (addToCentre)
+                addToPattern(pattern, AvailableColumns / 2, siblings);
+
+            if (RandomStart > 0 && hasSpecialColumn(HitObject.Samples))
+                addToPattern(pattern, 0, siblings);
+
+            return pattern;
+        }
+
+        /// <summary>
+        /// Generates a count of notes to be generated from a list of probabilities.
+        /// </summary>
+        /// <param name="p2">Probability for 2 notes to be generated.</param>
+        /// <param name="p3">Probability for 3 notes to be generated.</param>
+        /// <param name="p4">Probability for 4 notes to be generated.</param>
+        /// <param name="p5">Probability for 5 notes to be generated.</param>
+        /// <returns>The amount of notes to be generated.</returns>
+        private int getRandomNoteCount(double p2, double p3, double p4, double p5)
+        {
+            switch (AvailableColumns)
+            {
+                case 2:
+                    p2 = 0;
+                    p3 = 0;
+                    p4 = 0;
+                    p5 = 0;
+                    break;
+                case 3:
+                    p2 = Math.Max(p2, 0.1);
+                    p3 = 0;
+                    p4 = 0;
+                    p5 = 0;
+                    break;
+                case 4:
+                    p2 = Math.Max(p2, 0.23);
+                    p3 = Math.Max(p3, 0.04);
+                    p4 = 0;
+                    p5 = 0;
+                    break;
+                case 5:
+                    p3 = Math.Max(p3, 0.15);
+                    p4 = Math.Max(p4, 0.03);
+                    p5 = 0;
+                    break;
+            }
+
+            if (HitObject.Samples.Any(s => s.Name == SampleInfo.HIT_CLAP))
+                p2 = 1;
+
+            return GetRandomNoteCount(p2, p3, p4, p5);
+        }
+
+        /// <summary>
+        /// Generates a count of notes to be generated from a list of probabilities.
+        /// </summary>
+        /// <param name="centreProbability">The probability for a note to be added to the centre column.</param>
+        /// <param name="p2">Probability for 2 notes to be generated.</param>
+        /// <param name="p3">Probability for 3 notes to be generated.</param>
+        /// <param name="addToCentre">Whether to add a note to the centre column.</param>
+        /// <returns>The amount of notes to be generated. The note to be added to the centre column will NOT be part of this count.</returns>
+        private int getRandomNoteCountMirrored(double centreProbability, double p2, double p3, out bool addToCentre)
+        {
+            addToCentre = false;
+
+            if ((convertType & PatternType.ForceNotStack) > 0)
+                return getRandomNoteCount(p2 / 2, p2, (p2 + p3) / 2, p3);
+
+            switch (AvailableColumns)
+            {
+                case 2:
+                    centreProbability = 0;
+                    p2 = 0;
+                    p3 = 0;
+                    break;
+                case 3:
+                    centreProbability = Math.Max(centreProbability, 0.03);
+                    p2 = Math.Max(p2, 0.1);
+                    p3 = 0;
+                    break;
+                case 4:
+                    centreProbability = 0;
+                    p2 = Math.Max(p2 * 2, 0.2);
+                    p3 = 0;
+                    break;
+                case 5:
+                    centreProbability = Math.Max(centreProbability, 0.03);
+                    p3 = 0;
+                    break;
+                case 6:
+                    centreProbability = 0;
+                    p2 = Math.Max(p2 * 2, 0.5);
+                    p3 = Math.Max(p3 * 2, 0.15);
+                    break;
+            }
+
+            double centreVal = Random.NextDouble();
+            int noteCount = GetRandomNoteCount(p2, p3);
+
+            addToCentre = AvailableColumns % 2 != 0 && noteCount != 3 && centreVal > 1 - centreProbability;
+            return noteCount;
+        }
+
+        /// <summary>
+        /// Constructs and adds a note to a pattern.
+        /// </summary>
+        /// <param name="pattern">The pattern to add to.</param>
+        /// <param name="column">The column to add the note to.</param>
+        /// <param name="siblings">The number of children alongside this note (these will not be generated, but are used for volume calculations).</param>
+        private void addToPattern(Pattern pattern, int column, int siblings = 1)
+        {
+            pattern.Add(new Note
+            {
+                StartTime = HitObject.StartTime,
+                Samples = HitObject.Samples,
+                Column = column,
+                Siblings = siblings
+            });
+        }
+    }
+}

osu.Game.Rulesets.Mania/osu.Game.Rulesets.Mania.csproj

@@ -49,6 +49,7 @@
   <ItemGroup>
     <Compile Include="Beatmaps\Patterns\Legacy\PatternGenerator.cs" />
     <Compile Include="Beatmaps\Patterns\PatternGenerator.cs" />
+    <Compile Include="Beatmaps\Patterns\Legacy\HitObjectPatternGenerator.cs" />
     <Compile Include="Beatmaps\Patterns\Legacy\PatternType.cs" />
     <Compile Include="Beatmaps\ManiaBeatmapConverter.cs" />
     <Compile Include="Beatmaps\Patterns\Pattern.cs" />