Rename OsuDifficulty -> Difficulty

osu.Game.Rulesets.Osu/Difficulty/OsuDifficultyCalculator.cs

@@ -0,0 +1,70 @@
+// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using System;
+using System.Collections.Generic;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Osu.Difficulty.Preprocessing;
+using osu.Game.Rulesets.Osu.Difficulty.Skills;
+using osu.Game.Rulesets.Osu.Objects;
+
+namespace osu.Game.Rulesets.Osu.Difficulty
+{
+    public class OsuDifficultyCalculator : DifficultyCalculator
+    {
+        private const int section_length = 400;
+        private const double difficulty_multiplier = 0.0675;
+
+        public OsuDifficultyCalculator(IBeatmap beatmap)
+            : base(beatmap)
+        {
+        }
+
+        public OsuDifficultyCalculator(IBeatmap beatmap, Mod[] mods)
+            : base(beatmap, mods)
+        {
+        }
+
+        public override double Calculate(Dictionary<string, double> categoryDifficulty = null)
+        {
+            OsuDifficultyBeatmap beatmap = new OsuDifficultyBeatmap((List<OsuHitObject>)Beatmap.HitObjects, TimeRate);
+            Skill[] skills =
+            {
+                new Aim(),
+                new Speed()
+            };
+
+            double sectionEnd = section_length / TimeRate;
+            foreach (OsuDifficultyHitObject h in beatmap)
+            {
+                while (h.BaseObject.StartTime > sectionEnd)
+                {
+                    foreach (Skill s in skills)
+                    {
+                        s.SaveCurrentPeak();
+                        s.StartNewSectionFrom(sectionEnd);
+                    }
+
+                    sectionEnd += section_length;
+                }
+
+                foreach (Skill s in skills)
+                    s.Process(h);
+            }
+
+            double aimRating = Math.Sqrt(skills[0].DifficultyValue()) * difficulty_multiplier;
+            double speedRating = Math.Sqrt(skills[1].DifficultyValue()) * difficulty_multiplier;
+
+            double starRating = aimRating + speedRating + Math.Abs(aimRating - speedRating) / 2;
+
+            if (categoryDifficulty != null)
+            {
+                categoryDifficulty.Add("Aim", aimRating);
+                categoryDifficulty.Add("Speed", speedRating);
+            }
+
+            return starRating;
+        }
+    }
+}