Migrate to a software rasterizer to dramatically improve performance

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

packages/wolf_3d_data/lib/src/wl_parser.dart

@@ -180,32 +180,33 @@ abstract class WLParser {
   // --- Private Helpers ---
 
   static Sprite _parseWallChunk(ByteData vswap, int offset) {
-    // Generate the 64x64 pixel grid in column-major order functionally
-    return List.generate(
-      64,
-      (x) => List.generate(64, (y) => vswap.getUint8(offset + (x * 64) + y)),
-    );
+    final pixels = Uint8List(64 * 64);
+    for (int x = 0; x < 64; x++) {
+      for (int y = 0; y < 64; y++) {
+        // Flat 1D index: x * 64 + y
+        pixels[x * 64 + y] = vswap.getUint8(offset + (x * 64) + y);
+      }
+    }
+    return Sprite(pixels);
   }
 
   static Sprite _parseSingleSprite(ByteData vswap, int offset) {
-    // Initialize the 64x64 grid with 255 (The Magenta Transparency Color!)
-    Sprite sprite = List.generate(64, (_) => List.filled(64, 255));
+    // Initialize the 1D array with 255 (Transparency)
+    final pixels = Uint8List(64 * 64)..fillRange(0, 4096, 255);
+    Sprite sprite = Sprite(pixels);
 
     int leftPix = vswap.getUint16(offset, Endian.little);
     int rightPix = vswap.getUint16(offset + 2, Endian.little);
 
-    // Parse vertical columns within the sprite bounds
     for (int x = leftPix; x <= rightPix; x++) {
       int colOffset = vswap.getUint16(
         offset + 4 + ((x - leftPix) * 2),
         Endian.little,
       );
-
       if (colOffset != 0) {
         _parseSpriteColumn(vswap, sprite, x, offset, offset + colOffset);
       }
     }
-
     return sprite;
   }
 
@@ -216,23 +217,21 @@ abstract class WLParser {
     int baseOffset,
     int cmdOffset,
   ) {
-    // Execute the column drawing commands
     while (true) {
       int endY = vswap.getUint16(cmdOffset, Endian.little);
-      if (endY == 0) break; // 0 marks the end of the column
-      endY ~/= 2; // Wolf3D stores Y coordinates multiplied by 2
+      if (endY == 0) break;
+      endY ~/= 2;
 
       int pixelOfs = vswap.getUint16(cmdOffset + 2, Endian.little);
-
       int startY = vswap.getUint16(cmdOffset + 4, Endian.little);
       startY ~/= 2;
 
       for (int y = startY; y < endY; y++) {
-        // The Carmack 286 Hack: pixelOfs + y gives the exact byte address
-        sprite[x][y] = vswap.getUint8(baseOffset + pixelOfs + y);
+        // Write directly to the 1D array
+        sprite.pixels[x * 64 + y] = vswap.getUint8(baseOffset + pixelOfs + y);
       }
 
-      cmdOffset += 6; // Move to the next 6-byte instruction
+      cmdOffset += 6;
     }
   }