1 files changed, 207 insertions, 0 deletions
diff --git a/src/SMAPI/Framework/ContentManagers/ModContentManager.cs b/src/SMAPI/Framework/ContentManagers/ModContentManager.cs
new file mode 100644
index 00000000..80bf37e9
--- /dev/null
+++ b/src/SMAPI/Framework/ContentManagers/ModContentManager.cs
@@ -0,0 +1,207 @@
+using System;
+using System.Globalization;
+using System.IO;
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+using StardewModdingAPI.Framework.Exceptions;
+using StardewModdingAPI.Framework.Reflection;
+using StardewValley;
+
+namespace StardewModdingAPI.Framework.ContentManagers
+{
+    /// <summary>A content manager which handles reading files from a SMAPI mod folder with support for unpacked files.</summary>
+    internal class ModContentManager : BaseContentManager
+    {
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="name">A name for the mod manager. Not guaranteed to be unique.</param>
+        /// <param name="serviceProvider">The service provider to use to locate services.</param>
+        /// <param name="rootDirectory">The root directory to search for content.</param>
+        /// <param name="currentCulture">The current culture for which to localise content.</param>
+        /// <param name="coordinator">The central coordinator which manages content managers.</param>
+        /// <param name="monitor">Encapsulates monitoring and logging.</param>
+        /// <param name="reflection">Simplifies access to private code.</param>
+        /// <param name="onDisposing">A callback to invoke when the content manager is being disposed.</param>
+        public ModContentManager(string name, IServiceProvider serviceProvider, string rootDirectory, CultureInfo currentCulture, ContentCoordinator coordinator, IMonitor monitor, Reflector reflection, Action<BaseContentManager> onDisposing)
+                : base(name, serviceProvider, rootDirectory, currentCulture, coordinator, monitor, reflection, onDisposing, isModFolder: true) { }
+
+        /// <summary>Load an asset that has been processed by the content pipeline.</summary>
+        /// <typeparam name="T">The type of asset to load.</typeparam>
+        /// <param name="assetName">The asset path relative to the loader root directory, not including the <c>.xnb</c> extension.</param>
+        /// <param name="language">The language code for which to load content.</param>
+        public override T Load<T>(string assetName, LanguageCode language)
+        {
+            assetName = this.AssertAndNormaliseAssetName(assetName);
+
+            // get from cache
+            if (this.IsLoaded(assetName))
+                return base.Load<T>(assetName, language);
+
+            // get managed asset
+            if (this.Coordinator.TryParseManagedAssetKey(assetName, out string contentManagerID, out string relativePath))
+            {
+                if (contentManagerID != this.Name)
+                {
+                    T data = this.Coordinator.LoadAndCloneManagedAsset<T>(assetName, contentManagerID, relativePath, language);
+                    this.Inject(assetName, data);
+                    return data;
+                }
+
+                return this.LoadManagedAsset<T>(assetName, contentManagerID, relativePath, language);
+            }
+
+            throw new NotSupportedException("Can't load content folder asset from a mod content manager.");
+        }
+
+        /// <summary>Create a new content manager for temporary use.</summary>
+        public override LocalizedContentManager CreateTemporary()
+        {
+            throw new NotSupportedException("Can't create a temporary mod content manager.");
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Get whether an asset has already been loaded.</summary>
+        /// <param name="normalisedAssetName">The normalised asset name.</param>
+        protected override bool IsNormalisedKeyLoaded(string normalisedAssetName)
+        {
+            return this.Cache.ContainsKey(normalisedAssetName);
+        }
+
+        /// <summary>Load a managed mod asset.</summary>
+        /// <typeparam name="T">The type of asset to load.</typeparam>
+        /// <param name="internalKey">The internal asset key.</param>
+        /// <param name="contentManagerID">The unique name for the content manager which should load this asset.</param>
+        /// <param name="relativePath">The relative path within the mod folder.</param>
+        /// <param name="language">The language code for which to load content.</param>
+        private T LoadManagedAsset<T>(string internalKey, string contentManagerID, string relativePath, LanguageCode language)
+        {
+            SContentLoadException GetContentError(string reasonPhrase) => new SContentLoadException($"Failed loading asset '{relativePath}' from {contentManagerID}: {reasonPhrase}");
+            try
+            {
+                // get file
+                FileInfo file = this.GetModFile(relativePath);
+                if (!file.Exists)
+                    throw GetContentError("the specified path doesn't exist.");
+
+                // load content
+                switch (file.Extension.ToLower())
+                {
+                    // XNB file
+                    case ".xnb":
+                        return base.Load<T>(relativePath, language);
+
+                    // unpacked map
+                    case ".tbin":
+                        throw GetContentError($"can't read unpacked map file directly from the underlying content manager. It must be loaded through the mod's {typeof(IModHelper)}.{nameof(IModHelper.Content)} helper.");
+
+                    // unpacked image
+                    case ".png":
+                        // validate
+                        if (typeof(T) != typeof(Texture2D))
+                            throw GetContentError($"can't read file with extension '{file.Extension}' as type '{typeof(T)}'; must be type '{typeof(Texture2D)}'.");
+
+                        // fetch & cache
+                        using (FileStream stream = File.OpenRead(file.FullName))
+                        {
+                            Texture2D texture = Texture2D.FromStream(Game1.graphics.GraphicsDevice, stream);
+                            texture = this.PremultiplyTransparency(texture);
+                            this.Inject(internalKey, texture);
+                            return (T)(object)texture;
+                        }
+
+                    default:
+                        throw GetContentError($"unknown file extension '{file.Extension}'; must be one of '.png', '.tbin', or '.xnb'.");
+                }
+            }
+            catch (Exception ex) when (!(ex is SContentLoadException))
+            {
+                if (ex.GetInnermostException() is DllNotFoundException dllEx && dllEx.Message == "libgdiplus.dylib")
+                    throw GetContentError("couldn't find libgdiplus, which is needed to load mod images. Make sure Mono is installed and you're running the game through the normal launcher.");
+                throw new SContentLoadException($"The content manager failed loading content asset '{relativePath}' from {contentManagerID}.", ex);
+            }
+        }
+
+        /// <summary>Get a file from the mod folder.</summary>
+        /// <param name="path">The asset path relative to the content folder.</param>
+        private FileInfo GetModFile(string path)
+        {
+            // try exact match
+            FileInfo file = new FileInfo(Path.Combine(this.FullRootDirectory, path));
+
+            // try with default extension
+            if (!file.Exists && file.Extension.ToLower() != ".xnb")
+            {
+                FileInfo result = new FileInfo(file.FullName + ".xnb");
+                if (result.Exists)
+                    file = result;
+            }
+
+            return file;
+        }
+
+        /// <summary>Premultiply a texture's alpha values to avoid transparency issues in the game. This is only possible if the game isn't currently drawing.</summary>
+        /// <param name="texture">The texture to premultiply.</param>
+        /// <returns>Returns a premultiplied texture.</returns>
+        /// <remarks>Based on <a href="https://gist.github.com/Layoric/6255384">code by Layoric</a>.</remarks>
+        private Texture2D PremultiplyTransparency(Texture2D texture)
+        {
+            // validate
+            if (Context.IsInDrawLoop)
+                throw new NotSupportedException("Can't load a PNG file while the game is drawing to the screen. Make sure you load content outside the draw loop.");
+
+            // process texture
+            SpriteBatch spriteBatch = Game1.spriteBatch;
+            GraphicsDevice gpu = Game1.graphics.GraphicsDevice;
+            using (RenderTarget2D renderTarget = new RenderTarget2D(Game1.graphics.GraphicsDevice, texture.Width, texture.Height))
+            {
+                // create blank render target to premultiply
+                gpu.SetRenderTarget(renderTarget);
+                gpu.Clear(Color.Black);
+
+                // multiply each color by the source alpha, and write just the color values into the final texture
+                spriteBatch.Begin(SpriteSortMode.Immediate, new BlendState
+                {
+                    ColorDestinationBlend = Blend.Zero,
+                    ColorWriteChannels = ColorWriteChannels.Red | ColorWriteChannels.Green | ColorWriteChannels.Blue,
+                    AlphaDestinationBlend = Blend.Zero,
+                    AlphaSourceBlend = Blend.SourceAlpha,
+                    ColorSourceBlend = Blend.SourceAlpha
+                });
+                spriteBatch.Draw(texture, texture.Bounds, Color.White);
+                spriteBatch.End();
+
+                // copy the alpha values from the source texture into the final one without multiplying them
+                spriteBatch.Begin(SpriteSortMode.Immediate, new BlendState
+                {
+                    ColorWriteChannels = ColorWriteChannels.Alpha,
+                    AlphaDestinationBlend = Blend.Zero,
+                    ColorDestinationBlend = Blend.Zero,
+                    AlphaSourceBlend = Blend.One,
+                    ColorSourceBlend = Blend.One
+                });
+                spriteBatch.Draw(texture, texture.Bounds, Color.White);
+                spriteBatch.End();
+
+                // release GPU
+                gpu.SetRenderTarget(null);
+
+                // extract premultiplied data
+                Color[] data = new Color[texture.Width * texture.Height];
+                renderTarget.GetData(data);
+
+                // unset texture from GPU to regain control
+                gpu.Textures[0] = null;
+
+                // update texture with premultiplied data
+                texture.SetData(data);
+            }
+
+            return texture;
+        }
+    }
+}