Move ShpTD sprite loading into Mods.Common.

OpenRA.Mods.Common/SpriteLoaders/ShpTDLoader.cs

@@ -0,0 +1,239 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2014 The OpenRA Developers (see AUTHORS)
+ * 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. For more information,
+ * see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.IO;
+using System.Linq;
+using OpenRA.FileFormats;
+using OpenRA.Graphics;
+
+namespace OpenRA.Mods.Common.SpriteLoaders
+{
+	public class ShpTDLoader : ISpriteLoader
+	{
+		static bool IsShpTD(Stream s)
+		{
+			var start = s.Position;
+
+			// First word is the image count
+			var imageCount = s.ReadUInt16();
+			if (imageCount == 0)
+			{
+				s.Position = start;
+				return false;
+			}
+
+			// Last offset should point to the end of file
+			var finalOffset = start + 14 + 8 * imageCount;
+			if (finalOffset > s.Length)
+			{
+				s.Position = start;
+				return false;
+			}
+
+			s.Position = finalOffset;
+			var eof = s.ReadUInt32();
+			if (eof != s.Length)
+			{
+				s.Position = start;
+				return false;
+			}
+
+			// Check the format flag on the first frame
+			s.Position = start + 17;
+			var b = s.ReadUInt8();
+
+			s.Position = start;
+			return b == 0x20 || b == 0x40 || b == 0x80;
+		}
+
+		public bool TryParseSprite(Stream s, out ISpriteFrame[] frames)
+		{
+			if (!IsShpTD(s))
+			{
+				frames = null;
+				return false;
+			}
+
+			frames = new ShpTDSprite(s).Frames.ToArray();
+			return true;
+		}
+	}
+
+	public class ShpTDSprite
+	{
+		enum Format { Format20 = 0x20, Format40 = 0x40, Format80 = 0x80 }
+
+		class ImageHeader : ISpriteFrame
+		{
+			public Size Size { get { return reader.Size; } }
+			public Size FrameSize { get { return reader.Size; } }
+			public float2 Offset { get { return float2.Zero; } }
+			public byte[] Data { get; set; }
+			public bool DisableExportPadding { get { return false; } }
+
+			public uint FileOffset;
+			public Format Format;
+
+			public uint RefOffset;
+			public Format RefFormat;
+			public ImageHeader RefImage;
+
+			ShpTDSprite reader;
+
+			// Used by ShpWriter
+			public ImageHeader() { }
+
+			public ImageHeader(Stream stream, ShpTDSprite reader)
+			{
+				this.reader = reader;
+				var data = stream.ReadUInt32();
+				FileOffset = data & 0xffffff;
+				Format = (Format)(data >> 24);
+
+				RefOffset = stream.ReadUInt16();
+				RefFormat = (Format)stream.ReadUInt16();
+			}
+
+			public void WriteTo(BinaryWriter writer)
+			{
+				writer.Write(FileOffset | ((uint)Format << 24));
+				writer.Write((ushort)RefOffset);
+				writer.Write((ushort)RefFormat);
+			}
+		}
+
+		public IReadOnlyList<ISpriteFrame> Frames { get; private set; }
+		public readonly Size Size;
+
+		int recurseDepth = 0;
+		readonly int imageCount;
+
+		readonly long shpBytesFileOffset;
+		readonly byte[] shpBytes;
+
+		public ShpTDSprite(Stream stream)
+		{
+			imageCount = stream.ReadUInt16();
+			stream.Position += 4;
+			var width = stream.ReadUInt16();
+			var height = stream.ReadUInt16();
+			Size = new Size(width, height);
+
+			stream.Position += 4;
+			var headers = new ImageHeader[imageCount];
+			Frames = headers.AsReadOnly();
+			for (var i = 0; i < headers.Length; i++)
+				headers[i] = new ImageHeader(stream, this);
+
+			// Skip eof and zero headers
+			stream.Position += 16;
+
+			var offsets = headers.ToDictionary(h => h.FileOffset, h => h);
+			for (var i = 0; i < imageCount; i++)
+			{
+				var h = headers[i];
+				if (h.Format == Format.Format20)
+					h.RefImage = headers[i - 1];
+				else if (h.Format == Format.Format40 && !offsets.TryGetValue(h.RefOffset, out h.RefImage))
+					throw new InvalidDataException("Reference doesnt point to image data {0}->{1}".F(h.FileOffset, h.RefOffset));
+			}
+
+			shpBytesFileOffset = stream.Position;
+			shpBytes = stream.ReadBytes((int)(stream.Length - stream.Position));
+
+			foreach (var h in headers)
+				Decompress(h);
+		}
+
+		void Decompress(ImageHeader h)
+		{
+			// No extra work is required for empty frames
+			if (h.Size.Width == 0 || h.Size.Height == 0)
+				return;
+
+			if (recurseDepth > imageCount)
+				throw new InvalidDataException("Format20/40 headers contain infinite loop");
+
+			switch (h.Format)
+			{
+				case Format.Format20:
+				case Format.Format40:
+				{
+					if (h.RefImage.Data == null)
+					{
+						++recurseDepth;
+						Decompress(h.RefImage);
+						--recurseDepth;
+					}
+
+					h.Data = CopyImageData(h.RefImage.Data);
+					Format40.DecodeInto(shpBytes, h.Data, (int)(h.FileOffset - shpBytesFileOffset));
+					break;
+				}
+
+				case Format.Format80:
+				{
+					var imageBytes = new byte[Size.Width * Size.Height];
+					Format80.DecodeInto(shpBytes, imageBytes, (int)(h.FileOffset - shpBytesFileOffset));
+					h.Data = imageBytes;
+					break;
+				}
+
+				default:
+					throw new InvalidDataException();
+			}
+		}
+
+		byte[] CopyImageData(byte[] baseImage)
+		{
+			var imageData = new byte[Size.Width * Size.Height];
+			Array.Copy(baseImage, imageData, imageData.Length);
+			return imageData;
+		}
+
+		public static void Write(Stream s, Size size, IEnumerable<byte[]> frames)
+		{
+			var compressedFrames = frames.Select(f => Format80.Encode(f)).ToArray();
+
+			// note: end-of-file and all-zeroes headers
+			var dataOffset = 14 + (compressedFrames.Length + 2) * 8;
+
+			using (var bw = new BinaryWriter(s))
+			{
+				bw.Write((ushort)compressedFrames.Length);
+				bw.Write((ushort)0);
+				bw.Write((ushort)0);
+				bw.Write((ushort)size.Width);
+				bw.Write((ushort)size.Height);
+				bw.Write((uint)0);
+
+				foreach (var f in compressedFrames)
+				{
+					var ih = new ImageHeader { Format = Format.Format80, FileOffset = (uint)dataOffset };
+					dataOffset += f.Length;
+
+					ih.WriteTo(bw);
+				}
+
+				var eof = new ImageHeader { FileOffset = (uint)dataOffset };
+				eof.WriteTo(bw);
+
+				var allZeroes = new ImageHeader { };
+				allZeroes.WriteTo(bw);
+
+				foreach (var f in compressedFrames)
+					bw.Write(f);
+			}
+		}
+	}
+}