Added OsuModWiggle class and adjusted OsuRuleset.cs

osu.Game.Rulesets.Osu/Mods/OsuModWiggle.cs

@@ -0,0 +1,82 @@
+// 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.Framework.Graphics;
+using osu.Game.Graphics;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Osu.Objects;
+using OpenTK;
+
+namespace osu.Game.Rulesets.Osu.Mods
+{
+    internal class OsuModWiggle : Mod, IApplicableToDrawableHitObjects
+    {
+        public override string Name => "Wiggle";
+        public override string ShortenedName => "WG";
+        public override FontAwesome Icon => FontAwesome.fa_arrows_alt;
+        public override ModType Type => ModType.Fun;
+        public override string Description => "They just won't stay still...";
+        public override double ScoreMultiplier => 1;
+
+        private readonly int wiggle_delay = 90;      // (ms) Higher = fewer wiggles
+        private readonly int wiggle_strength = 10;   // Higher = stronger wiggles
+        
+        public void ApplyToDrawableHitObjects(IEnumerable<DrawableHitObject> drawables)
+        {
+            foreach(var drawable in drawables)
+                drawable.ApplyCustomUpdateState += drawableOnApplyCustomUpdateState;
+        }
+
+        private void drawableOnApplyCustomUpdateState(DrawableHitObject drawable, ArmedState state)
+        {
+            var hitObject = (OsuHitObject)drawable.HitObject;
+            Vector2 origPos = drawable.Position;
+            
+            Random distRand = new Random(hitObject.ComboOffset);
+            Random angleRand = new Random(hitObject.IndexInCurrentCombo);
+
+            // Wiggle all objects during TimePreempt
+            int amountWiggles = (int)hitObject.TimePreempt / wiggle_delay;
+
+            for (int i = 0; i < amountWiggles; i++)
+            {
+                using (drawable.BeginAbsoluteSequence(hitObject.StartTime - hitObject.TimePreempt + i * wiggle_delay, true))
+                {
+                    float nextAngle = (float)(angleRand.NextDouble() * 2 * Math.PI);
+                    float nextDist = (float)(distRand.NextDouble() * wiggle_strength);
+                    Vector2 wiggledPos = new Vector2((float)(nextDist * Math.Cos(nextAngle) + origPos.X), (float)(nextDist * Math.Sin(nextAngle) + origPos.Y));
+                    drawable.MoveTo(wiggledPos, wiggle_delay);
+                }
+            }
+
+            // Keep wiggling sliders and spinners for their duration
+            double objDuration;
+            if (hitObject is Slider slider)
+            {
+                objDuration = slider.Duration;
+            }
+            else if (hitObject is Spinner spinner)
+            {
+                objDuration = spinner.Duration;
+            }
+            else
+                return;
+
+            amountWiggles = (int)(objDuration / wiggle_delay);
+
+            for (int i = 0; i < amountWiggles; i++)
+            {
+                using (drawable.BeginAbsoluteSequence(hitObject.StartTime + i * wiggle_delay, true))
+                {
+                    float nextAngle = (float)(angleRand.NextDouble() * 2 * Math.PI);
+                    float nextDist = (float)(distRand.NextDouble() * wiggle_strength);
+                    Vector2 wiggledPos = new Vector2((float)(nextDist * Math.Cos(nextAngle) + origPos.X), (float)(nextDist * Math.Sin(nextAngle) + origPos.Y));
+                    drawable.MoveTo(wiggledPos, wiggle_delay);
+                }
+            }
+        }
+    }
+}

osu.Game.Rulesets.Osu/OsuRuleset.cs

@@ -117,6 +117,11 @@ namespace osu.Game.Rulesets.Osu
                         new OsuModRelax(),
                         new OsuModAutopilot(),
                     };
+                case ModType.Fun:
+                    return new Mod[]
+                    {
+                        new OsuModWiggle(),
+                    };
                 default:
                     return new Mod[] { };
             }