Initial commit: OpenRA game engine

Fork from OpenRA/OpenRA with one-click launch script (start-ra.cmd)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

OpenRA.Game/Graphics/SpriteLoader.cs

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+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.IO;
+using OpenRA.FileSystem;
+using OpenRA.Primitives;
+
+namespace OpenRA.Graphics
+{
+	/// <summary>
+	/// Describes the format of the pixel data in a ISpriteFrame.
+	/// Note that the channel order is defined for little-endian bytes, so BGRA corresponds
+	/// to a 32bit ARGB value, such as that returned by Color.ToArgb().
+	/// </summary>
+	public enum SpriteFrameType
+	{
+		/// <summary>
+		/// 8 bit index into an external palette.
+		/// </summary>
+		Indexed8,
+
+		/// <summary>
+		/// 32 bit color such as returned by Color.ToArgb() or the bmp file format
+		/// (remember that little-endian systems place the little bits in the first byte).
+		/// </summary>
+		Bgra32,
+
+		/// <summary>
+		/// Like BGRA, but without an alpha channel.
+		/// </summary>
+		Bgr24,
+
+		/// <summary>
+		/// 32 bit color in big-endian format, like png.
+		/// </summary>
+		Rgba32,
+
+		/// <summary>
+		/// Like RGBA, but without an alpha channel.
+		/// </summary>
+		Rgb24
+	}
+
+	public interface ISpriteLoader
+	{
+		bool TryParseSprite(Stream s, string filename, out ISpriteFrame[] frames, out TypeDictionary metadata);
+	}
+
+	public interface ISpriteFrame
+	{
+		SpriteFrameType Type { get; }
+
+		/// <summary>
+		/// Size of the frame's `Data`.
+		/// </summary>
+		Size Size { get; }
+
+		/// <summary>
+		/// Size of the entire frame including the frame's `Size`.
+		/// Think of this like a picture frame.
+		/// </summary>
+		Size FrameSize { get; }
+
+		float2 Offset { get; }
+		byte[] Data { get; }
+		bool DisableExportPadding { get; }
+	}
+
+	public class FrameCache
+	{
+		readonly Cache<string, ISpriteFrame[]> frames;
+
+		public FrameCache(IReadOnlyFileSystem fileSystem, ISpriteLoader[] loaders)
+		{
+			frames = new Cache<string, ISpriteFrame[]>(filename => FrameLoader.GetFrames(fileSystem, filename, loaders, out _));
+		}
+
+		public ISpriteFrame[] this[string filename] => frames[filename];
+	}
+
+	public static class FrameLoader
+	{
+		public static ISpriteFrame[] GetFrames(IReadOnlyFileSystem fileSystem, string filename, ISpriteLoader[] loaders, out TypeDictionary metadata)
+		{
+			using (var stream = fileSystem.Open(filename))
+			{
+				var spriteFrames = GetFrames(stream, loaders, filename, out metadata);
+				if (spriteFrames == null)
+					throw new InvalidDataException(filename + " is not a valid sprite file!");
+
+				return spriteFrames;
+			}
+		}
+
+		public static ISpriteFrame[] GetFrames(Stream stream, ISpriteLoader[] loaders, string filename, out TypeDictionary metadata)
+		{
+			metadata = null;
+
+			foreach (var loader in loaders)
+				if (loader.TryParseSprite(stream, filename, out var frames, out metadata))
+					return frames;
+
+			return null;
+		}
+	}
+}