support variable map sizes in saves/scenarios/landscapes (#217)

Author: LeftofZen

Dat/Data/Constants.cs

@@ -30,8 +30,8 @@ public static class Limits
 	public const size_t kMaxNormalEntities = kMaxEntities - kMaxMoneyEntities;
 	// Money is not counted in this limit
 	public const size_t kMaxMiscEntities = 4000;
-	public const int kMapRows = 384;
-	public const int kMapColumns = 384;
+	public const int kMapColumnsVanilla = 384;
+	public const int kMapRowsVanilla = 384;
 
 	public const int kMaxObjectTypes = 34;
 	public const int kMaxSawyerEncodings = 4;

Dat/Types/SCV5/S5File.cs

@@ -104,6 +104,25 @@ uint32_t Checksum
 	public List<TileElement>[,]? TileElementMap { get; set; }
 	byte[] OriginalTileElementData { get; set; } = [];
 
+	public (int Width, int Height) GetMapSize()
+		=> GetMapSize(SaveDetails, ScenarioOptions);
+
+	public static (int Width, int Height) GetMapSize(SaveDetails saveDetails, ScenarioOptions scenarioOptions)
+	{
+		if (saveDetails != null)
+		{
+			return (saveDetails.MapSizeX, saveDetails.MapSizeY);
+		}
+		else if (scenarioOptions != null)
+		{
+			return (scenarioOptions.MapSizeX, scenarioOptions.MapSizeY);
+		}
+		else
+		{
+			return (Limits.kMapColumnsVanilla, Limits.kMapRowsVanilla);
+		}
+	}
+
 	public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
 		=> [];
 
@@ -215,6 +234,8 @@ public static S5File Read(ReadOnlySpan<byte> data)
 		byte[] tileElementData = [];
 		IGameState gameState;
 
+		var mapSize = GetMapSize(saveDetails, scenarioOptions);
+
 		if (header.Type == S5FileType.Scenario)
 		{
 			var gameStateA = SawyerStreamReader.ReadChunk<GameStateScenarioA>(ref data);
@@ -228,7 +249,7 @@ public static S5File Read(ReadOnlySpan<byte> data)
 			if (gameStateA.GameStateFlags.HasFlag(GameStateFlags.TileManagerLoaded))
 			{
 				tileElementData = SawyerStreamReader.ReadChunkCore(ref data).ToArray();
-				(tileElements, tileElementMap) = ParseTileElements(tileElementData);
+				(tileElements, tileElementMap) = ParseTileElements(tileElementData, mapSize.Width, mapSize.Height);
 			}
 		}
 		else
@@ -237,7 +258,7 @@ public static S5File Read(ReadOnlySpan<byte> data)
 			FixState();
 
 			tileElementData = SawyerStreamReader.ReadChunkCore(ref data).ToArray();
-			(tileElements, tileElementMap) = ParseTileElements(tileElementData);
+			(tileElements, tileElementMap) = ParseTileElements(tileElementData, mapSize.Width, mapSize.Height);
 		}
 
 		var checksum = BitConverter.ToUInt32(data[0..4]);
@@ -249,12 +270,12 @@ public static S5File Read(ReadOnlySpan<byte> data)
 	static void FixState()
 	{ }
 
-	static (List<TileElement>, List<TileElement>[,]) ParseTileElements(ReadOnlySpan<byte> tileElementData)
+	static (List<TileElement>, List<TileElement>[,]) ParseTileElements(ReadOnlySpan<byte> tileElementData, int mapWidth, int mapHeight)
 	{
 		var numTileElements = tileElementData.Length / TileElement.StructLength;
 
 		List<TileElement> tileElements = [];
-		var tileElementMap = new List<TileElement>[Limits.kMapColumns, Limits.kMapRows];
+		var tileElementMap = new List<TileElement>[mapWidth, mapHeight];
 
 		var x = 0;
 		var y = 0;
@@ -275,12 +296,12 @@ static void FixState()
 
 			if (el.IsLast())
 			{
-				if (x == Limits.kMapColumns - 1)
+				if (x == mapWidth - 1)
 				{
-					y = (y + 1) % Limits.kMapRows;
+					y = (y + 1) % mapHeight;
 				}
 
-				x = (x + 1) % Limits.kMapColumns;
+				x = (x + 1) % mapWidth;
 			}
 
 			// el.IsLast() indicates its the last element on that tile

Dat/Types/SCV5/SaveDetails.cs

@@ -17,7 +17,9 @@ public record SaveDetails(
 	[property: LocoStructOffset(0x247)] byte var_247,
 	[property: LocoStructOffset(0x248), LocoArrayLength(250 * 200), Browsable(false)] uint8_t[] Image,
 	[property: LocoStructOffset(0xC598)] CompanyFlags ChallengeFlags,
-	[property: LocoStructOffset(0xC59C), LocoArrayLength(124), Browsable(false)] byte[] var_C59C)
+	[property: LocoStructOffset(0xC59C)] uint16_t MapSizeX,
+	[property: LocoStructOffset(0xC59E)] uint16_t MapSizeY,
+	[property: LocoStructOffset(0xC5A0), LocoArrayLength(120), Browsable(false)] byte[] var_C59C)
 	: ILocoStruct
 {
 	public const int StructLength = 0xC618;

Dat/Types/SCV5/ScenarioOptions.cs

@@ -47,7 +47,9 @@ public record ScenarioOptions(
 	[property: LocoStructOffset(0x41C1)] uint8_t MaxRiverWidth,
 	[property: LocoStructOffset(0x41C2)] uint8_t RiverbankWidth,
 	[property: LocoStructOffset(0x41C3)] uint8_t RiverMeanderRate,
-	[property: LocoStructOffset(0x41C4), LocoArrayLength(342), Browsable(false)] byte[] var_41C4)
+	[property: LocoStructOffset(0x41C4)] uint16_t MapSizeX,
+	[property: LocoStructOffset(0x41C6)] uint16_t MapSizeY,
+	[property: LocoStructOffset(0x41C8), LocoArrayLength(338), Browsable(false)] byte[] var_41C8)
 	: ILocoStruct
 {
 	public const int StructLength = 0x431A;

Gui/ViewModels/LocoTypes/SCV5ViewModel.cs

@@ -38,14 +38,14 @@ public class SCV5ViewModel : BaseFileViewModel
 	[Reactive]
 	public Dictionary<ElementType, Bitmap> Maps { get; set; }
 
-	[Reactive, Range(0, Limits.kMapColumns - 1)]
+	[Reactive, Range(0, Limits.kMapColumnsVanilla - 1)]
 	public int TileElementX { get; set; }
 
-	[Reactive, Range(0, Limits.kMapRows - 1)]
+	[Reactive, Range(0, Limits.kMapRowsVanilla - 1)]
 	public int TileElementY { get; set; }
 
 	public ObservableCollection<TileElement> CurrentTileElements
-		=> CurrentS5File?.TileElementMap != null && TileElementX >= 0 && TileElementX < 384 && TileElementY >= 0 && TileElementY < 384
+		=> CurrentS5File?.TileElementMap != null && TileElementX >= 0 && TileElementX < CurrentS5File.GetMapSize().Width && TileElementY >= 0 && TileElementY < CurrentS5File.GetMapSize().Height
 			? [.. CurrentS5File.TileElementMap[TileElementX, TileElementY]]
 			: [];
 
@@ -199,7 +199,8 @@ async Task DownloadMissingObjects(GameObjDataFolder targetFolder)
 
 	void DrawMap()
 	{
-		Map = new WriteableBitmap(new Avalonia.PixelSize(384, 384), new Avalonia.Vector(92, 92), Avalonia.Platform.PixelFormat.Rgba8888);
+		(var mapWidth, var mapHeight) = CurrentS5File.GetMapSize();
+		Map = new WriteableBitmap(new Avalonia.PixelSize(mapWidth, mapHeight), new Avalonia.Vector(92, 92), Avalonia.Platform.PixelFormat.Rgba8888);
 		using (var fb = Map.Lock())
 		{
 			var teMap = CurrentS5File!.TileElementMap!;
@@ -211,7 +212,7 @@ void DrawMap()
 					unsafe
 					{
 						var rgba = (byte*)fb.Address;
-						var idx = ((x * 384) + y) * 4; // not sure why this has to be reversed to match loco
+						var idx = ((x * mapWidth) + y) * 4; // not sure why this has to be reversed to match loco
 
 						if (el.Type == ElementType.Surface)
 						{