Added audio loading and decompressing

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

packages/wolf_3d_data/lib/src/wl_parser.dart

@@ -47,6 +47,8 @@ abstract class WLParser {
       vgaDict: await fileFetcher('VGADICT.$ext'),
       vgaHead: await fileFetcher('VGAHEAD.$ext'),
       vgaGraph: await fileFetcher('VGAGRAPH.$ext'),
+      audioHed: await fileFetcher('AUDIOHED.$ext'),
+      audioT: await fileFetcher('AUDIOT.$ext'),
     );
   }
 
@@ -61,9 +63,13 @@ abstract class WLParser {
     required ByteData vgaDict,
     required ByteData vgaHead,
     required ByteData vgaGraph,
+    required ByteData audioHed,
+    required ByteData audioT,
   }) {
     final isShareware = version == GameVersion.shareware;
 
+    final audio = parseAudio(audioHed, audioT);
+
     return WolfensteinData(
       version: version,
       walls: parseWalls(vswap),
@@ -71,6 +77,8 @@ abstract class WLParser {
       sounds: parseSounds(vswap).map((bytes) => PcmSound(bytes)).toList(),
       levels: parseMaps(mapHead, gameMaps, isShareware: isShareware),
       vgaImages: parseVgaImages(vgaDict, vgaHead, vgaGraph),
+      adLibSounds: audio.adLib,
+      music: audio.music,
     );
   }
 
@@ -289,6 +297,56 @@ abstract class WLParser {
     return levels;
   }
 
+  /// Extracts AdLib sounds and IMF music tracks from the audio files.
+  static ({List<AdLibSound> adLib, List<ImfMusic> music}) parseAudio(
+    ByteData audioHed,
+    ByteData audioT,
+  ) {
+    List<int> offsets = [];
+    // AUDIOHED is a series of 32-bit unsigned integers
+    for (int i = 0; i < audioHed.lengthInBytes ~/ 4; i++) {
+      offsets.add(audioHed.getUint32(i * 4, Endian.little));
+    }
+
+    List<Uint8List> allAudioChunks = [];
+
+    for (int i = 0; i < offsets.length - 1; i++) {
+      int start = offsets[i];
+      int next = offsets[i + 1];
+
+      // 0xFFFFFFFF (or 4294967295) marks an empty slot
+      if (start == 0xFFFFFFFF || start >= audioT.lengthInBytes) {
+        allAudioChunks.add(Uint8List(0));
+        continue;
+      }
+
+      int length = next - start;
+      if (length <= 0) {
+        allAudioChunks.add(Uint8List(0));
+      } else {
+        allAudioChunks.add(
+          audioT.buffer.asUint8List(audioT.offsetInBytes + start, length),
+        );
+      }
+    }
+
+    // Wolfenstein 3D split:
+    // Chunks 0-299: AdLib Sounds
+    // Chunks 300+: IMF Music
+    List<AdLibSound> adLib = allAudioChunks
+        .take(300)
+        .map((bytes) => AdLibSound(bytes))
+        .toList();
+
+    List<ImfMusic> music = allAudioChunks
+        .skip(300)
+        .where((chunk) => chunk.isNotEmpty)
+        .map((bytes) => ImfMusic(bytes))
+        .toList();
+
+    return (adLib: adLib, music: music);
+  }
+
   // --- ALGORITHM 1: CARMACK EXPANSION ---
   static Uint16List _expandCarmack(Uint8List compressed) {
     ByteData data = ByteData.sublistView(compressed);