render method

void render(Canvas canvas, TileSource tile, { Rect? clip, required double zoomScaleFactor, required double zoom, required double rotation, })

renders the given tile to the canvas

zoomScaleFactor the 1-dimensional scale at which the tile is being rendered. If the tile is being rendered at twice it's normal size along the x-axis, the zoomScaleFactor would be 2. 1.0 indicates that no scaling is being applied. zoom the current zoom level, which is used to filter theme layers via minzoom and maxzoom. Value must be >= 0 and <= 24 tile the tile to render clip the optional clip to constrain tile rendering, used to limit drawing so that a portion of a tile can be rendered to a canvas

Implementation

void render(Canvas canvas, TileSource tile,
    {Rect? clip,
    required double zoomScaleFactor,
    required double zoom,
    required double rotation}) {
  profileSync('Render', () {
    final tileSpace =
        Rect.fromLTWH(0, 0, tileSize.toDouble(), tileSize.toDouble());
    canvas.save();
    canvas.clipRect(tileSpace);
    final tileClip = clip ?? tileSpace;
    final optimizations = Optimizations(
        skipInBoundsChecks: clip == null ||
            (tileClip.width - tileSpace.width).abs() < (tileSpace.width / 2));
    final context = Context(
        logger: logger,
        canvas: canvas,
        featureRenderer: featureRenderer,
        tileSource: tile,
        zoomScaleFactor: zoomScaleFactor,
        zoom: zoom,
        rotation: rotation,
        tileSpace: tileSpace,
        tileClip: tileClip,
        optimizations: optimizations,
        textPainterProvider: painterProvider);
    final effectiveTheme = theme.atZoom(zoom);
    for (final themeLayer in effectiveTheme.layers) {
      logger.log(() => 'rendering theme layer ${themeLayer.id}');
      themeLayer.render(context);
    }
    canvas.restore();
  });
}