Fix for map screens crashing the game if they are "background-only"

editor/Cartridge.cs

@@ -1701,7 +1701,7 @@ private void ReadAssets()
  {
  // We assume these are set second so we have to check if it's a set or overlay
  var tileMap = new TileMap(Memory, offset, asset.GetLength(Memory));
- if (tileMap.IsOverlay() && item.TileMap != null)
+ if (item.TileMap != null && item.TileMap.HasForeground)
  {
  item.TileMap.OverlayWith(tileMap);
  _assetsLookup[asset] = item.TileMap; // Point at the same object for both

editor/GameObjects/TileMap.cs

@@ -25,10 +25,16 @@ public void SetAllForeground()
  {
  _data[i] |= 0x1000;
  }
+ HasForeground = true;
  }
 
  public void OverlayWith(TileMap other)
  {
+ // Extend data if smaller (should not happen)
+ if (other._data.Count > _data.Count)
+ {
+ _data.AddRange(Enumerable.Repeat((ushort)0, other._data.Count - _data.Count));
+ }
  for (var i = 0; i < _data.Count; i++)
  {
  if (other._data[i] != 0xff)
@@ -40,9 +46,10 @@ public void OverlayWith(TileMap other)
 
  public Bitmap GetImage(TileSet tileSet, Palette palette)
  {
- var image = new Bitmap(256, 192, PixelFormat.Format8bppIndexed);
- // We work in 8bpp again...
- image.Palette = palette.ImagePalette;
+ var image = new Bitmap(256, 192, PixelFormat.Format8bppIndexed)
+ {
+ Palette = palette.ImagePalette
+ };
  var data = image.LockBits(new Rectangle(0, 0, image.Width, image.Height), ImageLockMode.WriteOnly, PixelFormat.Format8bppIndexed);
  try
  {
@@ -79,10 +86,11 @@ public Bitmap GetImage(TileSet tileSet, Palette palette)
  public int Offset { get; set; }
  public int ForegroundTileMapSize { get; private set; }
  public int BackgroundTileMapSize { get; private set; }
+ public bool HasForeground { get; private set; }
 
  public IList<byte> GetData()
  {
- if (!_data.Any(x => x > 0xff))
+ if (!HasForeground)
  {
  // Single tilemap mode
  var tileMap = Compression.CompressRle(_data.Select(x => (byte)x).ToArray());