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Assets/Plugins/Animancer/Utilities/SpriteRendererTextureSwap.cs

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+// Animancer // https://kybernetik.com.au/animancer // Copyright 2018-2023 Kybernetik //
+
+#pragma warning disable CS0649 // Field is never assigned to, and will always have its default value.
+
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace Animancer
+{
+    /// <summary>
+    /// Replaces the <see cref="SpriteRenderer.sprite"/> with a copy of it that uses a different <see cref="Texture"/>
+    /// during every <see cref="LateUpdate"/>.
+    /// </summary>
+    /// 
+    /// <remarks>
+    /// This script is not specific to Animancer and will work with any animation system if you remove the
+    /// [<see cref="AddComponentMenu"/>] and [<see cref="HelpURL"/>] attributes.
+    /// </remarks>
+    /// https://kybernetik.com.au/animancer/api/Animancer/SpriteRendererTextureSwap
+    /// 
+    [AddComponentMenu(Strings.MenuPrefix + "Sprite Renderer Texture Swap")]
+    [HelpURL(Strings.DocsURLs.APIDocumentation + "/" + nameof(SpriteRendererTextureSwap))]
+    [DefaultExecutionOrder(DefaultExecutionOrder)]
+    public class SpriteRendererTextureSwap : MonoBehaviour
+    {
+        /************************************************************************************************************************/
+
+        /// <summary>Execute very late (32000 is last).</summary>
+        public const int DefaultExecutionOrder = 30000;
+
+        /************************************************************************************************************************/
+
+        [SerializeField]
+        [Tooltip("The SpriteRenderer that will have its Sprite modified")]
+        private SpriteRenderer _Renderer;
+
+        /// <summary>The <see cref="SpriteRenderer"/> that will have its <see cref="Sprite"/> modified.</summary>
+        public ref SpriteRenderer Renderer => ref _Renderer;
+
+        /************************************************************************************************************************/
+
+        [SerializeField]
+        [Tooltip("The replacement for the original Sprite texture")]
+        private Texture2D _Texture;
+
+        /// <summary>The replacement for the original <see cref="Sprite.texture"/>.</summary>
+        /// <remarks>
+        /// If this texture has any <see cref="Sprite"/>s set up in its import settings, they will be completely
+        /// ignored because this system creates new <see cref="Sprite"/>s at runtime. The texture doesn't even need to
+        /// be set to <see cref="Sprite"/> mode.
+        /// <para></para>
+        /// Call <see cref="ClearCache"/> before setting this if you want to destroy any sprites created for the
+        /// previous texture.
+        /// </remarks>
+        public Texture2D Texture
+        {
+            get => _Texture;
+            set
+            {
+                _Texture = value;
+                RefreshSpriteMap();
+            }
+        }
+
+        /************************************************************************************************************************/
+
+        private Dictionary<Sprite, Sprite> _SpriteMap;
+
+        private void RefreshSpriteMap() => _SpriteMap = GetSpriteMap(_Texture);
+
+        /************************************************************************************************************************/
+
+        protected virtual void Awake() => RefreshSpriteMap();
+
+        protected virtual void OnValidate() => RefreshSpriteMap();
+
+        /************************************************************************************************************************/
+
+        protected virtual void LateUpdate()
+        {
+            if (_Renderer == null)
+                return;
+
+            var sprite = _Renderer.sprite;
+            if (TrySwapTexture(_SpriteMap, _Texture, ref sprite))
+                _Renderer.sprite = sprite;
+        }
+
+        /************************************************************************************************************************/
+
+        /// <summary>Destroys all sprites created for the current <see cref="Texture"/>.</summary>
+        public void ClearCache()
+        {
+            DestroySprites(_SpriteMap);
+        }
+
+        /************************************************************************************************************************/
+
+        private static readonly Dictionary<Texture2D, Dictionary<Sprite, Sprite>>
+            TextureToSpriteMap = new Dictionary<Texture2D, Dictionary<Sprite, Sprite>>();
+
+        /************************************************************************************************************************/
+
+        /// <summary>Returns a cached dictionary mapping original sprites to duplicates using the specified `texture`.</summary>
+        public static Dictionary<Sprite, Sprite> GetSpriteMap(Texture2D texture)
+        {
+            if (texture == null)
+                return null;
+
+            if (!TextureToSpriteMap.TryGetValue(texture, out var map))
+                TextureToSpriteMap.Add(texture, map = new Dictionary<Sprite, Sprite>());
+
+            return map;
+        }
+
+        /************************************************************************************************************************/
+
+        /// <summary>
+        /// If the <see cref="Sprite.texture"/> is not already using the specified `texture`, this method replaces the
+        /// `sprite` with a cached duplicate which uses that `texture` instead.
+        /// </summary>
+        public static bool TrySwapTexture(Dictionary<Sprite, Sprite> spriteMap, Texture2D texture, ref Sprite sprite)
+        {
+            if (spriteMap == null ||
+                sprite == null ||
+                texture == null ||
+                sprite.texture == texture)
+                return false;
+
+            if (!spriteMap.TryGetValue(sprite, out var otherSprite))
+            {
+                var pivot = sprite.pivot;
+                pivot.x /= sprite.rect.width;
+                pivot.y /= sprite.rect.height;
+
+                otherSprite = Sprite.Create(texture,
+                    sprite.rect, pivot, sprite.pixelsPerUnit,
+                    0, SpriteMeshType.FullRect, sprite.border, false);
+
+#if UNITY_ASSERTIONS
+                var name = sprite.name;
+                var originalTextureName = sprite.texture.name;
+                var index = name.IndexOf(originalTextureName);
+                if (index >= 0)
+                {
+                    var newName =
+                        texture.name +
+                        name.Substring(index + originalTextureName.Length, name.Length - (index + originalTextureName.Length));
+
+                    if (index > 0)
+                        newName = name.Substring(0, index) + newName;
+
+                    name = newName;
+                }
+
+                otherSprite.name = name;
+#endif
+
+                spriteMap.Add(sprite, otherSprite);
+            }
+
+            sprite = otherSprite;
+            return true;
+        }
+
+        /************************************************************************************************************************/
+
+        /// <summary>Destroys all the <see cref="Dictionary{TKey, TValue}.Values"/>.</summary>
+        public static void DestroySprites(Dictionary<Sprite, Sprite> spriteMap)
+        {
+            if (spriteMap == null)
+                return;
+
+            foreach (var sprite in spriteMap.Values)
+                Destroy(sprite);
+
+            spriteMap.Clear();
+        }
+
+        /************************************************************************************************************************/
+
+        /// <summary>Destroys all sprites created for the `texture`.</summary>
+        public static void DestroySprites(Texture2D texture)
+        {
+            if (TextureToSpriteMap.TryGetValue(texture, out var spriteMap))
+            {
+                TextureToSpriteMap.Remove(texture);
+                DestroySprites(spriteMap);
+            }
+        }
+
+        /************************************************************************************************************************/
+    }
+}