render method

@override void render(Buffer buffer, Rect area)

Renders the widget onto the provided buffer within the specified area.

Implementation

@override
void render(Buffer buffer, Rect area) {
  Tracer.record(_traceCanvasRenderId, Phase.begin);
  try {
    var currentBuffer = buffer;
    var startX = 0;
    var startY = 0;
    while (currentBuffer is Viewport) {
      startX += currentBuffer.bounds.x;
      startY += currentBuffer.bounds.y;
      currentBuffer = currentBuffer.parent;
    }
    final targetBuffer = currentBuffer;

    final targetWidth = targetBuffer.width;
    final targetHeight = targetBuffer.height;
    final targetCells = targetBuffer.cells;

    for (var cy = 0; cy < height; cy++) {
      final ty = startY + cy;
      if (ty < 0 || ty >= targetHeight) continue;

      for (var cx = 0; cx < width; cx++) {
        final tx = startX + cx;
        if (tx < 0 || tx >= targetWidth) continue;

        if (isOccluded != null && isOccluded!(cx, cy)) continue;

        final idx = cy * width + cx;
        final dots = _grid[idx];
        if (dots == 0 && _styles[idx] == null && style == Style.empty) {
          continue;
        }

        final String char;
        if (renderMode == CanvasRenderMode.quadrants) {
          char = _quadrantCache[dots];
        } else if (renderMode == CanvasRenderMode.density ||
            _antiAliased[idx] == 1) {
          char = _densityCache[dots];
        } else {
          char = _brailleCache[dots];
        }

        final targetIdx = ty * targetWidth + tx;
        final cell = targetCells[targetIdx];
        cell.char = char;
        final s = _styles[idx];
        if (s != null) {
          cell.style = Style(
            foreground: s.foreground ?? style.foreground,
            background: s.background ?? style.background,
            modifiers: s.modifiers | style.modifiers,
          );
        } else {
          cell.style = style;
        }
      }
    }
  } finally {
    Tracer.record(_traceCanvasRenderId, Phase.end);
  }
}