renderTo method

void renderTo(Screen screen, Rectangle area, { UvStyle fallbackStyle = const UvStyle(), })

Render this braille canvas into screen within area.

Implementation

void renderTo(
  Screen screen,
  Rectangle area, {
  UvStyle fallbackStyle = const UvStyle(),
}) {
  final bh = _dots.length;
  final bw = bh == 0 ? 0 : _dots[0].length;

  for (var cy = 0; cy < cellHeight && area.minY + cy < area.maxY; cy++) {
    for (var cx = 0; cx < cellWidth && area.minX + cx < area.maxX; cx++) {
      var codePoint = 0;
      UvStyle? style;
      final bx = cx * 2;
      final by = cy * 4;

      void sample(int dx, int dy, int bit) {
        final x = bx + dx;
        final y = by + dy;
        if (y >= 0 && y < bh && x >= 0 && x < bw) {
          final dotStyle = _dots[y][x];
          if (dotStyle != null) {
            codePoint |= bit;
            style ??= dotStyle;
          }
        }
      }

      sample(0, 0, 0x01);
      sample(0, 1, 0x02);
      sample(0, 2, 0x04);
      sample(0, 3, 0x40);
      sample(1, 0, 0x08);
      sample(1, 1, 0x10);
      sample(1, 2, 0x20);
      sample(1, 3, 0x80);

      if (codePoint != 0) {
        putCell(
          screen,
          area.minX + cx,
          area.minY + cy,
          String.fromCharCode(0x2800 + codePoint),
          style ?? fallbackStyle,
        );
      }
    }
  }
}