fix off-by-one string table parse error (#36)

* fix off-by-one string table parse error

* code cleanup

* code cleanup

Author: LeftofZen

Core/DatFileParsing/SawyerStreamReader.cs

@@ -1,4 +1,4 @@
-using System.Text;
+using System.Text;
 using OpenLoco.ObjectEditor.Headers;
 using OpenLoco.ObjectEditor.Objects;
 using OpenLoco.ObjectEditor.Types;
@@ -154,47 +154,47 @@ public static (DatFileInfo DatFileInfo, ILocoObject? LocoObject) LoadFullObjectF
 			return new(new DatFileInfo(s5Header, objectHeader), newObj);
 		}
 
+		static string CStringToString(ReadOnlySpan<byte> data, Encoding enc)
+		{
+			var ptr = 0;
+			while (data[ptr++] != '\0') ;
+			return enc.GetString(data[0..(ptr - 1)]); // do -1 to exclude the \0
+		}
+
+		static Dictionary<LanguageId, string> GetNewLanguageDictionary()
+		{
+			var languageDict = new Dictionary<LanguageId, string>();
+			foreach (var language in Enum.GetValues<LanguageId>())
+			{
+				languageDict.Add(language, string.Empty);
+			}
+			return languageDict;
+		}
+
 		public static (StringTable table, int bytesRead) LoadStringTable(ReadOnlySpan<byte> data, string[] stringNames, ILogger? logger = null)
 		{
 			var stringTable = new StringTable();
 
 			if (data.Length == 0 || stringNames.Length == 0)
 			{
+				logger?.Warning($"No data for language table");
 				return (stringTable, 0);
 			}
 
 			var ptr = 0;
 
 			foreach (var locoString in stringNames)
 			{
-				stringTable.Table.Add(locoString, []);
+				// init language table
+				stringTable.Table.Add(locoString, GetNewLanguageDictionary());
 				var languageDict = stringTable[locoString];
 
-				// add empty strings for every single language
-				foreach (var language in Enum.GetValues<LanguageId>())
-				{
-					languageDict.Add(language, string.Empty);
-				}
-
-				for (; ptr < data.Length && data[ptr] != 0xFF;)
+				// read string
+				for (; ptr < data.Length && data[ptr] != 0xFF; ++ptr)
 				{
 					var lang = (LanguageId)data[ptr++];
-					var ini = ptr;
-
-					while (data[ptr++] != '\0')
-					{
-						;
-					}
-
-					var str = Encoding.Latin1.GetString(data[ini..(ptr - 1)]); // do -1 to exclude the \0
-
-					if (!languageDict.ContainsKey(lang))
-					{
-						logger?.Error($"Skipping unknown language: \"{lang}\"");
-						break;
-					}
-
-					languageDict[lang] = str;
+					languageDict[lang] = CStringToString(data[ptr..], Encoding.Latin1);
+					ptr += languageDict[lang].Length;
 				}
 
 				ptr++; // add one because we skipped the 0xFF byte at the end

Core/Data/LanguageId.cs

@@ -1,4 +1,4 @@
-namespace OpenLoco.ObjectEditor.Data
+namespace OpenLoco.ObjectEditor.Data
 {
 	public enum LanguageId : uint8_t
 	{
@@ -16,7 +16,7 @@ public enum LanguageId : uint8_t
 		chinese_traditional,
 		id_12,
 		portuguese,
-		blank = 254,
-		end = 255
+		//blank = 254,
+		//end = 255
 	};
 }

Core/Objects/TrainSignalObject.cs

@@ -1,7 +1,8 @@
-using System.ComponentModel;
+using System.ComponentModel;
 using OpenLoco.ObjectEditor.Data;
 using OpenLoco.ObjectEditor.DatFileParsing;
 using OpenLoco.ObjectEditor.Headers;
+using OpenLoco.ObjectEditor.Types;
 
 namespace OpenLoco.ObjectEditor.Objects
 {
@@ -33,7 +34,7 @@ public record TrainSignalObject(
 		[property: LocoStructOffset(0x13), LocoArrayLength(TrainSignalObject.ModsLength), Browsable(false)] object_id[] ModHeaderIds,
 		[property: LocoStructOffset(0x1A)] uint16_t DesignedYear,
 		[property: LocoStructOffset(0x1C)] uint16_t ObsoleteYear
-	) : ILocoStruct, ILocoStructVariableData
+	) : ILocoStruct, ILocoStructVariableData, IImageTableStrings
 	{
 		public const int ModsLength = 7;
 
@@ -49,5 +50,16 @@ public ReadOnlySpan<byte> Save()
 			=> Mods
 			.SelectMany(mod => mod.Write().ToArray())
 			.ToArray();
+
+		public bool TryGetImageName(int id, out string? value)
+			=> ImageIdNameMap.TryGetValue(id, out value);
+
+		public static Dictionary<int, string> ImageIdNameMap = new()
+		{
+			{ 80, "redLights" },
+			{ 88, "redLights2" },
+			{ 96, "greenLights" },
+			{ 104, "greenLights2" },
+		};
 	}
 }

Gui/Gui.csproj

@@ -17,6 +17,7 @@
     <Authors>LeftofZen</Authors>
     <Product>$(AssemblyName) $(AssemblyVersion)</Product>
     <Version>$(AssemblyVersion)</Version>
+    <ProduceReferenceAssembly>False</ProduceReferenceAssembly>
   </PropertyGroup>
 
   <ItemGroup>

Gui/MainFormModel.cs

@@ -363,7 +363,7 @@ static void SerialiseHeaderIndexToFile(string filename, HeaderIndex headerIndex,
 			}
 			else
 			{
-				var obj = SawyerStreamReader.LoadFullObjectFromFile(filename);
+				var obj = SawyerStreamReader.LoadFullObjectFromFile(filename, logger: logger);
 				var uiObj = new UiLocoObject { DatFileInfo = obj.DatFileInfo, LocoObject = obj.LocoObject };
 				_ = ObjectCache.TryAdd(filename, uiObj);
 				return uiObj;