Function computeInteractionScalesGridCssPx

src/core/createRenderCoordinator.ts:2343–2377

(
    gridArea: GridArea,
    domains: { readonly xDomain: { readonly min: number; readonly max: number }; readonly yDomain: { readonly min: number; readonly max: number } }
  )

  };

  const computeInteractionScalesGridCssPx = (
    gridArea: GridArea,
    domains: { readonly xDomain: { readonly min: number; readonly max: number }; readonly yDomain: { readonly min: number; readonly max: number } }
  ):
    | {
        readonly xScale: LinearScale;
        readonly yScale: LinearScale;
        readonly plotWidthCss: number;
        readonly plotHeightCss: number;
      }
    | null => {
    const canvas = gpuContext.canvas;
    // Support both HTMLCanvasElement and OffscreenCanvas for worker thread compatibility
    if (!canvas) return null;

    const plotSize = getPlotSizeCssPx(canvas, gridArea);
    if (!plotSize) return null;

    // IMPORTANT: grid-local CSS px ranges (0..plotWidth/Height), for interaction hit-testing.
    const xScale = createLinearScale().domain(domains.xDomain.min, domains.xDomain.max).range(0, plotSize.plotWidthCss);
    const yScale = createLinearScale().domain(domains.yDomain.min, domains.yDomain.max).range(plotSize.plotHeightCss, 0);

    const result = { xScale, yScale, plotWidthCss: plotSize.plotWidthCss, plotHeightCss: plotSize.plotHeightCss };
    console.log('[computeInteractionScalesGridCssPx] Computed interaction scales:', {
      canvasType: isHTMLCanvasElement(canvas) ? 'HTMLCanvasElement' : 'OffscreenCanvas',
      plotWidthCss: result.plotWidthCss,
      plotHeightCss: result.plotHeightCss,
      xDomain: domains.xDomain,
      yDomain: domains.yDomain,
      xRange: [0, plotSize.plotWidthCss],
      yRange: [plotSize.plotHeightCss, 0]
    });

    return result;
  };

  const buildTooltipParams = (seriesIndex: number, dataIndex: number, point: DataPoint): TooltipParams => {
    const s = currentOptions.series[seriesIndex];