add a skipread attribute because we need to know the offsets to write 0 to for saving

Author: LeftofZen

OpenLocoTool/DatFileParsing/ByteReader.cs

@@ -109,6 +109,13 @@ public static ILocoStruct ReadLocoStruct(ReadOnlySpan<byte> data, Type t)
 					continue;
 				}
 
+				// ignore skipped properties (usually image ids and string ids which are only used in loco itself, not this tool
+				var skip = AttributeHelper.Get<LocoStructSkipReadAttribute>(p);
+				if (offsetAttr == null)
+				{
+					continue;
+				}
+
 				// special array handling
 				var arrLength = 0;
 				if (p.PropertyType.IsArray)

OpenLocoTool/DatFileParsing/ByteWriter.cs

@@ -106,6 +106,14 @@ public static ReadOnlySpan<byte> WriteLocoStruct(ILocoStruct obj)
 					continue;
 				}
 
+				// write 0s to properties that need it
+				var skip = AttributeHelper.Get<LocoStructSkipReadAttribute>(p);
+				if (skip != null)
+				{
+					WriteT(buf, p.PropertyType, offsetAttr.Offset, 0);
+					continue;
+				}
+
 				// special array handling
 				var arrLength = 0;
 				if (p.PropertyType.IsArray)

OpenLocoTool/DatFileParsing/LocoAttributes.cs

@@ -30,9 +30,9 @@ public class LocoStringTableAttribute(params string[] names) : Attribute
 	[AttributeUsage(AttributeTargets.Parameter | AttributeTargets.Property, AllowMultiple = false)]
 	public class LocoStructVariableLoadAttribute : Attribute
 	{ }
-	
+
 	// basically a 'skip' attribute to allow deferred loading for variable data, and writing of this property will be 0
 	[AttributeUsage(AttributeTargets.Parameter | AttributeTargets.Property, AllowMultiple = false)]
-	public class LocoStructZeroAttribute : Attribute
+	public class LocoStructSkipReadAttribute : Attribute
 	{ }
 }

OpenLocoTool/Objects/StreetLightObject.cs

@@ -8,9 +8,9 @@ namespace OpenLocoTool.Objects
 	[LocoStructSize(0xC)]
 	[LocoStringTable("Name")]
 	public record StreetLightObject(
-		//[property: LocoStructOffset(0x00)] string_id Name,
-		[property: LocoStructOffset(0x02), LocoArrayLength(StreetLightObject.DesignedYearLength)] uint16_t[] DesignedYear // 0x2
-																														  //[property: LocoStructOffset(0x08)] uint32_t Image
+		[property: LocoStructOffset(0x00), LocoStructSkipRead, Browsable(false)] string_id Name,
+		[property: LocoStructOffset(0x02), LocoArrayLength(StreetLightObject.DesignedYearLength)] uint16_t[] DesignedYear,
+		[property: LocoStructOffset(0x08), LocoStructSkipRead, Browsable(false)] uint32_t Image
 		) : ILocoStruct
 	{
 		public static ObjectType ObjectType => ObjectType.StreetLight;