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LegendLayer.update

Summary

LegendLayer.update repositions the legend, resolves source transform/colormap information, and redraws gradient/ticks when needed. It reacts to invalidation reasons such as scale, colormap, viewport, and layout changes. OverlaySystem calls this during update passes.

Syntax

LegendLayer.update(ctx: OverlayUpdateContext): void
layer.update(ctx);

Parameters

Name Type Required Description
ctx OverlayUpdateContext Yes Overlay frame context with camera, scene, viewport, and reason set.

Returns

void - No return value.

Type Details

OverlayUpdateContext

type OverlayUpdateContext = {
    camera: Camera;
    scene: Scene | null;
    width: number;
    height: number;
    dpr: number;
    nowMs: number;
    reasons: ReadonlySet<OverlayInvalidationReason>;
    root: HTMLDivElement;
};

Example

const canvas = document.querySelector("canvas");
const wgpu = await WasmGPU.create(canvas);

const overlay = wgpu.createOverlay.system({ autoUpdate: false });
const legend = wgpu.createOverlay.legend({
    source: { scaleTransform: { mode: "linear", domainMin: 0, domainMax: 10 }, colormap: "inferno" }
});
overlay.addLayer(legend);
overlay.update({ force: true, reasons: ["manual", "scale"] });

See Also