Custom Layer Renderer

Gives you complete control over how an entire layer is drawn. You receive the canvas, viewport, and layer — draw whatever you want. All coordinate transforms are your responsibility.

Quick start

1. Set CustomLayerRendererName on the layer:

var layer = new MemoryLayer("My Layer")
{
    Features = ...,
    CustomLayerRendererName = "my-layer-renderer"
};

2. Register your rendering function:

MapRenderer.RegisterLayerRenderer("my-layer-renderer", Render);

3. Implement the function:

void Render(SKCanvas canvas, Viewport viewport, ILayer layer, RenderService renderService)
{
    foreach (var feature in layer.GetFeatures(viewport.ToExtent(), viewport.Resolution))
    {
        var point = ((PointFeature)feature).Point;
        var (sx, sy) = viewport.WorldToScreenXY(point.X, point.Y);
        using var paint = new SKPaint { Color = SKColors.Purple, IsAntialias = true };
        canvas.DrawCircle((float)sx, (float)sy, 8f, paint);
    }
}

Sample

See the CustomLayerRenderer sample for a working example.

Additional notes

• You can reuse PointStyleRenderer.DrawPointStyle(...) inside your layer renderer to get the same transform behaviour as the Custom Point Style Renderer.
• Any layer Style set on the layer is ignored by the custom renderer — your function is called instead. Set it to null or a placeholder.
• If you use the experimental renderer, also register with Mapsui.Experimental.Rendering.Skia.MapRenderer.RegisterLayerRenderer(...).