refactor: Simplify column rendering logic in AsciiRenderer and SixelRenderer

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

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

@@ -861,12 +861,7 @@ class AsciiRenderer extends CliRendererBackend<dynamic> {
   }) {
     final List<int>? cachedColumn = _mainMenuBandFirstColumn;
     if (cachedColumn != null && cachedColumn.isNotEmpty) {
-      final int bandHeight = cachedColumn.length.clamp(0, 200);
+      _drawScaledColumnBand(cachedColumn);
-      for (int y = 0; y < bandHeight; y++) {
-        final int paletteIndex = cachedColumn[y];
-        final int fillIndex = paletteIndex == 0 ? 0 : paletteIndex;
-        _fillRect320(0, y, 320, 1, ColorPalette.vga32Bit[fillIndex]);
-      }
       return;
     }
 
@@ -888,12 +883,7 @@ class AsciiRenderer extends CliRendererBackend<dynamic> {
 
   void _drawMainMenuOptionsSideBars(VgaImage optionsLabel, int optionsX320) {
     _mainMenuBandFirstColumn = _cacheFirstColumn(optionsLabel);
-    final List<int> firstColumn = _mainMenuBandFirstColumn!;
+    _drawScaledColumnBand(_mainMenuBandFirstColumn!);
-    for (int y = 0; y < optionsLabel.height; y++) {
-      final int paletteIndex = firstColumn[y];
-      final int fillIndex = paletteIndex == 0 ? 0 : paletteIndex;
-      _fillRect320(0, y, 320, 1, ColorPalette.vga32Bit[fillIndex]);
-    }
   }
 
   List<int> _cacheFirstColumn(VgaImage image) {
@@ -904,6 +894,40 @@ class AsciiRenderer extends CliRendererBackend<dynamic> {
     return column;
   }
 
+  void _drawScaledColumnBand(List<int> column) {
+    if (column.isEmpty) {
+      return;
+    }
+
+    final int maxDrawHeight = _usesTerminalLayout
+        ? _terminalPixelHeight
+        : height;
+    final double scaleY = maxDrawHeight / 200.0;
+    final int destHeight = math.max(1, (column.length * scaleY).toInt());
+
+    for (int dy = 0; dy < destHeight; dy++) {
+      final int srcY = (dy / scaleY).toInt().clamp(0, column.length - 1);
+      final int fillColor = ColorPalette.vga32Bit[column[srcY]];
+
+      if (_usesTerminalLayout) {
+        if (dy < 0 || dy >= _terminalPixelHeight) {
+          continue;
+        }
+        for (int drawX = 0; drawX < _terminalSceneWidth; drawX++) {
+          _scenePixels[dy][drawX] = fillColor;
+        }
+      } else {
+        if (dy < 0 || dy >= height) {
+          continue;
+        }
+        final List<ColoredChar> row = _screen[dy];
+        for (int drawX = 0; drawX < width; drawX++) {
+          row[drawX] = ColoredChar(activeTheme.solid, fillColor);
+        }
+      }
+    }
+  }
+
   void _applyMenuFade(double alpha, int fadeColor) {
     if (alpha <= 0.0) {
       return;

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

@@ -698,39 +698,17 @@ class SixelRenderer extends CliRendererBackend<String> {
   }) {
     final List<int>? cachedColumn = _mainMenuBandFirstColumn;
     if (cachedColumn != null && cachedColumn.isNotEmpty) {
-      final int bandHeight = cachedColumn.length.clamp(0, 200);
+      _drawScaledColumnBand(cachedColumn);
-      for (int y = 0; y < bandHeight; y++) {
-        final int paletteIndex = cachedColumn[y];
-        final int fillIndex = paletteIndex == 0 ? 0 : paletteIndex;
-        _fillRect320(0, y, 320, 1, fillIndex);
-      }
       return;
     }
 
     final int mainBarTop = (headingY200 - 4).clamp(0, 199);
-
+    _fillRect320(0, mainBarTop, 320, 22, barColor);
-    _fillRect320(0, mainBarTop, 320, 18, barColor);
-
-    int stripeY = mainBarTop + 18;
-    for (int i = 0; i < 4; i++) {
-      _fillRect320(
-        0,
-        (stripeY + i).clamp(0, 199),
-        320,
-        1,
-        i.isEven ? barColor : backgroundColor,
-      );
-    }
   }
 
   void _drawMainMenuOptionsSideBars(VgaImage optionsLabel, int optionsX320) {
     _mainMenuBandFirstColumn = _cacheFirstColumn(optionsLabel);
-    final List<int> firstColumn = _mainMenuBandFirstColumn!;
+    _drawScaledColumnBand(_mainMenuBandFirstColumn!);
-    for (int y = 0; y < optionsLabel.height; y++) {
-      final int paletteIndex = firstColumn[y];
-      final int fillIndex = paletteIndex == 0 ? 0 : paletteIndex;
-      _fillRect320(0, y, 320, 1, fillIndex);
-    }
   }
 
   List<int> _cacheFirstColumn(VgaImage image) {
@@ -741,6 +719,33 @@ class SixelRenderer extends CliRendererBackend<String> {
     return column;
   }
 
+  void _drawScaledColumnBand(List<int> column) {
+    if (column.isEmpty) {
+      return;
+    }
+
+    final double scaleY = height / 200.0;
+    final int destHeight = math.max(1, (column.length * scaleY).toInt());
+
+    for (int dy = 0; dy < destHeight; dy++) {
+      final int drawY = dy;
+      if (drawY < 0 || drawY >= height) {
+        continue;
+      }
+
+      final int srcY = ((dy / destHeight) * column.length).toInt().clamp(
+        0,
+        column.length - 1,
+      );
+      final int paletteIndex = column[srcY];
+      final int fillIndex = paletteIndex == 0 ? 0 : paletteIndex;
+      final int rowStart = drawY * width;
+      for (int drawX = 0; drawX < width; drawX++) {
+        _screen[rowStart + drawX] = fillIndex;
+      }
+    }
+  }
+
   bool get _useCompactMenuLayout =>
       width < _compactMenuMinWidthPx || height < _compactMenuMinHeightPx;
 
@@ -782,9 +787,6 @@ class SixelRenderer extends CliRendererBackend<String> {
     int colorIndex, {
     int scale = 1,
   }) {
-    final double scaleX = width / 320.0;
-    final double scaleY = height / 200.0;
-
     int x320 = startX;
     for (final rune in text.runes) {
       final char = String.fromCharCode(rune).toUpperCase();
@@ -799,12 +801,7 @@ class SixelRenderer extends CliRendererBackend<String> {
             for (int sx = 0; sx < scale; sx++) {
               final int px320 = x320 + (col * scale) + sx;
               final int py200 = startY + (row * scale) + sy;
-
+              _fillRect320(px320, py200, 1, 1, colorIndex);
-              final int drawX = (px320 * scaleX).toInt();
-              final int drawY = (py200 * scaleY).toInt();
-              if (drawX >= 0 && drawX < width && drawY >= 0 && drawY < height) {
-                _screen[drawY * width + drawX] = colorIndex;
-              }
             }
           }
         }
@@ -1088,15 +1085,13 @@ class SixelRenderer extends CliRendererBackend<String> {
     final double scaleX = width / 320.0;
     final double scaleY = height / 200.0;
 
-    final int destStartX = (startX * scaleX).toInt();
+    final int destStartX = (startX * scaleX).floor();
-    final int destStartY = (startY * scaleY).toInt();
+    final int destEndX = ((startX + w) * scaleX).ceil();
-    final int destWidth = math.max(1, (w * scaleX).toInt());
+    final int destStartY = (startY * scaleY).floor();
-    final int destHeight = math.max(1, (h * scaleY).toInt());
+    final int destEndY = ((startY + h) * scaleY).ceil();
 
-    for (int dy = 0; dy < destHeight; dy++) {
+    for (int drawY = destStartY; drawY < destEndY; drawY++) {
-      for (int dx = 0; dx < destWidth; dx++) {
+      for (int drawX = destStartX; drawX < destEndX; drawX++) {
-        final int drawX = destStartX + dx;
-        final int drawY = destStartY + dy;
         if (drawX >= 0 && drawX < width && drawY >= 0 && drawY < height) {
           _screen[drawY * width + drawX] = colorIndex;
         }