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Custom Point Style Renderer

Renders individual point features with your own drawing code. The framework handles positioning, scaling, and rotation — you draw at (0, 0) and the symbol appears at the correct map location.

Quick start

1. Assign a CustomPointStyle to a layer: 

layer.Style = new CustomPointStyle { RendererName = "my-renderer" };

2. Register your drawing function: 

MapRenderer.RegisterPointStyleRenderer("my-renderer", Draw);

3. Implement the drawing function — draw at (0, 0): 

void Draw(SKCanvas canvas, IPointStyle style, RenderService renderService, float opacity)
{
    using var paint = new SKPaint { Color = SKColors.Blue, IsAntialias = true };
    canvas.DrawCircle(0f, 0f, 10f, paint);
}

By the time Draw is called the canvas has already been translated to the screen position and transformed for SymbolScale, SymbolRotation, and Offset.

Sample

See the CustomPointStyle samples for working examples (Basic, Advanced, Shader).

Additional notes

  • RelativeOffset is not applied automatically because the symbol's pixel size is not known by the framework. If you use it, apply it yourself: style.RelativeOffset.GetAbsoluteOffset(width, height).

Experimental renderer differences

When using the experimental renderer, also register with Mapsui.Experimental.Rendering.Skia.MapRenderer.RegisterPointStyleRenderer(...).

The experimental PointStyleRenderer.DrawPointStyle has an additional IFeature feature parameter compared to the regular renderer:

// Regular renderer
PointStyleRenderer.DrawPointStyle(canvas, viewport, x, y, style, renderService, opacity, renderHandler);

// Experimental renderer
PointStyleRenderer.DrawPointStyle(canvas, viewport, x, y, style, feature, renderService, opacity, renderHandler);

The RenderHandler delegate signature is the same in both — this only matters if you call DrawPointStyle directly (e.g. from a custom layer renderer).