shp writer

OpenRA.FileFormats/Graphics/ShpWriter.cs

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+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+
+namespace OpenRA.FileFormats.Graphics
+{
+	// format80-only SHP writer
+
+	public static class ShpWriter
+	{
+		public static void Write(Stream s, int width, int height, 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) * ImageHeader.SizeOnDisk;
+
+			using (var bw = new BinaryWriter(s))
+			{
+				bw.Write((ushort)compressedFrames.Length);
+				bw.Write((ushort)0);	// unused
+				bw.Write((ushort)0);	// unused
+				bw.Write((ushort)width);
+				bw.Write((ushort)height);
+				bw.Write((uint)0);		// unused
+
+				foreach (var f in compressedFrames)
+				{
+					var ih = new ImageHeader { Format = Format.Format80, Offset = (uint)dataOffset };
+					dataOffset += f.Length;
+
+					ih.WriteTo(bw);
+				}
+
+				var eof = new ImageHeader { Format = Format.Format80, Offset = (uint)dataOffset };
+				eof.WriteTo(bw);
+
+				var allZeroes = new ImageHeader { };
+				allZeroes.WriteTo(bw);
+
+				foreach (var f in compressedFrames)
+					bw.Write(f);
+			}
+		}
+	}
+}