From 8a513003ce38f4212e9f40f90c21ec1555ca1c0d Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Wed, 26 Oct 2022 17:32:26 +0900
Subject: [PATCH] Add argon droplet

---
 .../Skinning/Argon/ArgonDropletPiece.cs       | 118 ++++++++++++++++++
 .../Argon/CatchArgonSkinTransformer.cs        |   3 +
 .../Skinning/Default/DropletPiece.cs          |   2 +-
 3 files changed, 122 insertions(+), 1 deletion(-)
 create mode 100644 osu.Game.Rulesets.Catch/Skinning/Argon/ArgonDropletPiece.cs

diff --git a/osu.Game.Rulesets.Catch/Skinning/Argon/ArgonDropletPiece.cs b/osu.Game.Rulesets.Catch/Skinning/Argon/ArgonDropletPiece.cs
new file mode 100644
index 0000000000..c607b96729
--- /dev/null
+++ b/osu.Game.Rulesets.Catch/Skinning/Argon/ArgonDropletPiece.cs
@@ -0,0 +1,118 @@
+// 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 osu.Framework.Allocation;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Framework.Graphics.Sprites;
+using osu.Framework.Graphics.Textures;
+using osu.Framework.Utils;
+using osu.Game.Rulesets.Catch.Skinning.Default;
+using osu.Game.Rulesets.Catch.UI;
+using osuTK;
+
+namespace osu.Game.Rulesets.Catch.Skinning.Argon
+{
+    internal class ArgonDropletPiece : CatchHitObjectPiece
+    {
+        protected override Drawable HyperBorderPiece => hyperBorderPiece;
+
+        private Drawable hyperBorderPiece = null!;
+
+        private Container layers = null!;
+
+        private float rotationRandomness;
+
+        [BackgroundDependencyLoader]
+        private void load(TextureStore textures)
+        {
+            RelativeSizeAxes = Axes.Both;
+
+            const float droplet_scale_down = 0.5f;
+
+            InternalChildren = new[]
+            {
+                new Circle
+                {
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    Size = new Vector2(20),
+                },
+                layers = new Container
+                {
+                    Scale = new Vector2(droplet_scale_down),
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    RelativeSizeAxes = Axes.Both,
+                    Children = new Drawable[]
+                    {
+                        new Sprite
+                        {
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            Blending = BlendingParameters.Additive,
+                            Alpha = 0.15f,
+                            Texture = getTexture("A")
+                        },
+                        new Sprite
+                        {
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            Blending = BlendingParameters.Additive,
+                            Alpha = 0.5f,
+                            Scale = new Vector2(0.8f),
+                            Texture = getTexture("A")
+                        },
+                    }
+                },
+                hyperBorderPiece = new Sprite
+                {
+                    Scale = new Vector2(droplet_scale_down),
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    Colour = Catcher.DEFAULT_HYPER_DASH_COLOUR,
+                    Blending = BlendingParameters.Additive,
+                    Alpha = 0.15f,
+                    Texture = getTexture("A"),
+                },
+            };
+
+            Texture getTexture(string type) => textures.Get($"Gameplay/catch/blob-{type}{RNG.Next(1, 7)}");
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            AccentColour.BindValueChanged(colour =>
+            {
+                foreach (var sprite in layers)
+                    sprite.Colour = colour.NewValue;
+            }, true);
+
+            rotationRandomness = RNG.NextSingle(0.2f, 1);
+        }
+
+        protected override void Update()
+        {
+            base.Update();
+
+            // Note that droplets are rotated at a higher level, so this is mostly just to create more
+            // random arrangements of the multiple layers than actually rotate.
+            //
+            // Because underlying rotation is always clockwise, we apply anti-clockwise resistance to avoid
+            // making things spin too fast.
+            for (int i = 0; i < layers.Count; i++)
+            {
+                layers[i].Rotation -=
+                    // Layers are ordered from largest to smallest. Smaller layers should rotate more.
+                    (i * 4)
+                    * (float)Clock.ElapsedFrameTime
+                    * 0.2f * rotationRandomness
+                    // Each layer should alternate rotation direction.
+                    * (i % 2 == 1 ? 0.5f : 1);
+            }
+        }
+    }
+}
diff --git a/osu.Game.Rulesets.Catch/Skinning/Argon/CatchArgonSkinTransformer.cs b/osu.Game.Rulesets.Catch/Skinning/Argon/CatchArgonSkinTransformer.cs
index b55706b6d0..76a5b221fd 100644
--- a/osu.Game.Rulesets.Catch/Skinning/Argon/CatchArgonSkinTransformer.cs
+++ b/osu.Game.Rulesets.Catch/Skinning/Argon/CatchArgonSkinTransformer.cs
@@ -29,6 +29,9 @@ namespace osu.Game.Rulesets.Catch.Skinning.Argon
 
                         case CatchSkinComponents.Banana:
                             return new ArgonBananaPiece();
+
+                        case CatchSkinComponents.Droplet:
+                            return new ArgonDropletPiece();
                     }
 
                     break;
diff --git a/osu.Game.Rulesets.Catch/Skinning/Default/DropletPiece.cs b/osu.Game.Rulesets.Catch/Skinning/Default/DropletPiece.cs
index e4c2f04476..b8ae062382 100644
--- a/osu.Game.Rulesets.Catch/Skinning/Default/DropletPiece.cs
+++ b/osu.Game.Rulesets.Catch/Skinning/Default/DropletPiece.cs
@@ -17,7 +17,7 @@ namespace osu.Game.Rulesets.Catch.Skinning.Default
         {
             Size = new Vector2(CatchHitObject.OBJECT_RADIUS / 2);
 
-            InternalChildren = new Drawable[]
+            InternalChildren = new[]
             {
                 new Pulp
                 {