feat: Implement ASCII theme cycling and add quadrant theme support

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

packages/wolf_3d_dart/lib/src/rendering/ascii_renderer.dart

@@ -1,3 +1,4 @@
+import 'dart:developer' show log;
 import 'dart:math' as math;
 
 import 'package:arcane_helper_utils/arcane_helper_utils.dart';
@@ -35,9 +36,9 @@ class AsciiTheme {
 /// A collection of pre-defined character sets
 abstract class AsciiThemes {
   static const AsciiTheme blocks = AsciiTheme('Blocks', "█▓▒░ ");
-  static const AsciiTheme classic = AsciiTheme('Classic', "@%#*+=-:. ");
+  static const AsciiTheme quadrant = AsciiTheme('Quadrant', "▛▜▟▙▚▞▖ ");
 
-  static const List<AsciiTheme> values = [blocks, classic];
+  static const List<AsciiTheme> values = [blocks, quadrant];
 
   static AsciiTheme nextOf(AsciiTheme current) {
     final int currentIndex = values.indexOf(current);
@@ -111,6 +112,26 @@ class AsciiRenderer extends CliRendererBackend<dynamic> {
 
   late List<List<ColoredChar>> _screen;
   late List<List<int>> _scenePixels;
+  String? _lastLoggedThemeName;
+
+  static const List<String> _quadrantByMask = <String>[
+    ' ',
+    '▘',
+    '▝',
+    '▀',
+    '▖',
+    '▌',
+    '▞',
+    '▛',
+    '▗',
+    '▚',
+    '▐',
+    '▜',
+    '▄',
+    '▙',
+    '▟',
+    '█',
+  ];
 
   @override
   final double aspectMultiplier;
@@ -148,6 +169,10 @@ class AsciiRenderer extends CliRendererBackend<dynamic> {
 
   int get _terminalPixelHeight => _usesTerminalLayout ? height * 2 : height;
 
+  int get _terminalSceneWidth => width;
+
+  bool get _usesQuadrantCompose => activeTheme == AsciiThemes.quadrant;
+
   int get _viewportRightX => projectionOffsetX + projectionWidth;
 
   int get _terminalBackdropColor =>
@@ -157,6 +182,7 @@ class AsciiRenderer extends CliRendererBackend<dynamic> {
   @override
   /// Initializes the character grid before running the shared render pipeline.
   dynamic render(WolfEngine engine) {
+    _logThemeIfChanged();
     _screen = List.generate(
       engine.frameBuffer.height,
       (_) => List.filled(
@@ -1224,7 +1250,10 @@ class AsciiRenderer extends CliRendererBackend<dynamic> {
       for (int dx = 0; dx < w; dx++) {
         int x = startX + dx;
         int y = startY + dy;
-        if (x >= 0 && x < width && y >= 0 && y < _terminalPixelHeight) {
+        if (x >= 0 &&
+            x < _terminalSceneWidth &&
+            y >= 0 &&
+            y < _terminalPixelHeight) {
           _scenePixels[y][x] = color;
         }
       }
@@ -1309,8 +1338,13 @@ class AsciiRenderer extends CliRendererBackend<dynamic> {
       int topY = y * 2;
       int bottomY = math.min(topY + 1, _terminalPixelHeight - 1);
       for (int x = 0; x < width; x++) {
-        int topColor = _scenePixels[topY][x];
-        int bottomColor = _scenePixels[bottomY][x];
+        final int leftX = x;
+        final int rightX = _usesQuadrantCompose
+            ? math.min(x + 1, _terminalSceneWidth - 1)
+            : leftX;
+
+        int topColor = _scenePixels[topY][leftX];
+        int bottomColor = _scenePixels[bottomY][leftX];
 
         ColoredChar overlay = _screen[y][x];
         if (overlay.char != ' ') {
@@ -1322,7 +1356,12 @@ class AsciiRenderer extends CliRendererBackend<dynamic> {
             _screen[y][x] = ColoredChar(
               overlay.char,
               overlay.rawColor,
-              bottomColor,
+              _usesQuadrantCompose
+                  ? _blendPackedColors(
+                      _scenePixels[bottomY][leftX],
+                      _scenePixels[bottomY][rightX],
+                    )
+                  : bottomColor,
             );
           }
           continue;
@@ -1331,13 +1370,109 @@ class AsciiRenderer extends CliRendererBackend<dynamic> {
         // Pack two scene rows into one cell for both terminal and Flutter grid
         // modes. Overlay characters above keep a null background in Flutter
         // mode, so this does not introduce text background artifacts.
-        _screen[y][x] = topColor == bottomColor
-            ? ColoredChar('█', topColor)
-            : ColoredChar('▀', topColor, bottomColor);
+        if (_usesQuadrantCompose) {
+          final (char, fgColor, bgColor) = _composeQuadrantCell(
+            _scenePixels[topY][leftX],
+            _scenePixels[topY][rightX],
+            _scenePixels[bottomY][leftX],
+            _scenePixels[bottomY][rightX],
+          );
+          _screen[y][x] = bgColor == null
+              ? ColoredChar(char, fgColor)
+              : ColoredChar(char, fgColor, bgColor);
+          continue;
+        }
+
+        if (topColor == bottomColor) {
+          _screen[y][x] = ColoredChar('█', topColor);
+          continue;
+        }
+
+        _screen[y][x] = ColoredChar('▀', topColor, bottomColor);
       }
     }
   }
 
+  (String char, int fgColor, int? bgColor) _composeQuadrantCell(
+    int topLeft,
+    int topRight,
+    int bottomLeft,
+    int bottomRight,
+  ) {
+    final List<int> samples = <int>[topLeft, topRight, bottomLeft, bottomRight];
+    int bgColor = samples.first;
+    int bgCount = 0;
+    for (final candidate in samples) {
+      final int count = samples.where((value) => value == candidate).length;
+      if (count > bgCount) {
+        bgColor = candidate;
+        bgCount = count;
+      }
+    }
+
+    int fgColor = bgColor;
+    double fgDistance = -1.0;
+    for (final candidate in samples) {
+      final double distance = _packedColorDistance(candidate, bgColor);
+      if (distance > fgDistance) {
+        fgDistance = distance;
+        fgColor = candidate;
+      }
+    }
+
+    if (fgColor == bgColor) {
+      return ('█', fgColor, null);
+    }
+
+    int mask = 0;
+    if (_packedColorDistance(topLeft, fgColor) <=
+        _packedColorDistance(topLeft, bgColor)) {
+      mask |= 1;
+    }
+    if (_packedColorDistance(topRight, fgColor) <=
+        _packedColorDistance(topRight, bgColor)) {
+      mask |= 2;
+    }
+    if (_packedColorDistance(bottomLeft, fgColor) <=
+        _packedColorDistance(bottomLeft, bgColor)) {
+      mask |= 4;
+    }
+    if (_packedColorDistance(bottomRight, fgColor) <=
+        _packedColorDistance(bottomRight, bgColor)) {
+      mask |= 8;
+    }
+
+    if (mask == 0) {
+      return (' ', bgColor, null);
+    }
+    if (mask == 15) {
+      return ('█', fgColor, null);
+    }
+    return (_quadrantByMask[mask], fgColor, bgColor);
+  }
+
+  void _logThemeIfChanged() {
+    if (_lastLoggedThemeName == activeTheme.name) {
+      return;
+    }
+    _lastLoggedThemeName = activeTheme.name;
+    log('ASCII renderer theme: ${activeTheme.name}', name: 'AsciiRenderer');
+  }
+
+  int _blendPackedColors(int a, int b) {
+    final int r = (((a & 0xFF) + (b & 0xFF)) / 2).round();
+    final int g = ((((a >> 8) & 0xFF) + ((b >> 8) & 0xFF)) / 2).round();
+    final int blue = ((((a >> 16) & 0xFF) + ((b >> 16) & 0xFF)) / 2).round();
+    return 0xFF000000 | (blue << 16) | (g << 8) | r;
+  }
+
+  double _packedColorDistance(int a, int b) {
+    final int dr = (a & 0xFF) - (b & 0xFF);
+    final int dg = ((a >> 8) & 0xFF) - ((b >> 8) & 0xFF);
+    final int db = ((a >> 16) & 0xFF) - ((b >> 16) & 0xFF);
+    return (dr * dr + dg * dg + db * db).toDouble();
+  }
+
   /// Converts the current frame to a single printable ANSI string
   StringBuffer toAnsiString() {
     StringBuffer buffer = StringBuffer();

packages/wolf_3d_dart/lib/wolf_3d_renderer.dart

@@ -3,7 +3,7 @@ library;
 export 'src/raycasting/projection.dart';
 export 'src/raycasting/raycaster.dart';
 export 'src/rendering/ascii_renderer.dart'
-    show AsciiRenderer, AsciiRendererMode, ColoredChar;
+    show AsciiRenderer, AsciiRendererMode, AsciiTheme, AsciiThemes, ColoredChar;
 export 'src/rendering/cli_renderer_backend.dart';
 export 'src/rendering/renderer_backend.dart';
 export 'src/rendering/sixel_renderer.dart';

packages/wolf_3d_dart/test/rendering/ascii_themes_test.dart

@@ -0,0 +1,20 @@
+import 'package:test/test.dart';
+import 'package:wolf_3d_dart/wolf_3d_renderer.dart';
+
+void main() {
+  group('AsciiThemes', () {
+    test('contains quadrant as a selectable style', () {
+      expect(AsciiThemes.values, contains(AsciiThemes.quadrant));
+    });
+
+    test('cycles through blocks and quadrant', () {
+      expect(AsciiThemes.nextOf(AsciiThemes.blocks), AsciiThemes.quadrant);
+      expect(AsciiThemes.nextOf(AsciiThemes.quadrant), AsciiThemes.blocks);
+    });
+
+    test('defaults to first style when unknown style is provided', () {
+      const custom = AsciiTheme('Custom', 'Xx ');
+      expect(AsciiThemes.nextOf(custom), AsciiThemes.blocks);
+    });
+  });
+}

packages/wolf_3d_renderer/lib/wolf_3d_ascii_renderer.dart

@@ -7,9 +7,12 @@ import 'package:wolf_3d_renderer/base_renderer.dart';
 
 /// Displays the game using a text-mode approximation of the original renderer.
 class WolfAsciiRenderer extends BaseWolfRenderer {
+  final AsciiTheme theme;
+
   /// Creates an ASCII renderer bound to [engine].
   const WolfAsciiRenderer({
     required super.engine,
+    this.theme = AsciiThemes.blocks,
     super.onKeyEvent,
     super.key,
   });
@@ -30,6 +33,7 @@ class _WolfAsciiRendererState extends BaseWolfRendererState<WolfAsciiRenderer> {
   @override
   void initState() {
     super.initState();
+    _asciiRenderer.activeTheme = widget.theme;
     // ASCII output uses a reduced logical framebuffer because glyph rendering
     // expands the final view significantly once laid out in Flutter text.
     if (widget.engine.frameBuffer.width != _renderWidth ||
@@ -38,6 +42,14 @@ class _WolfAsciiRendererState extends BaseWolfRendererState<WolfAsciiRenderer> {
     }
   }
 
+  @override
+  void didUpdateWidget(covariant WolfAsciiRenderer oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (oldWidget.theme != widget.theme) {
+      _asciiRenderer.activeTheme = widget.theme;
+    }
+  }
+
   @override
   Color get scaffoldColor => widget.engine.difficulty == null
       ? _colorFromRgb(widget.engine.menuBackgroundRgb)