Function prepare

src/renderers/createScatterDensityRenderer.ts:360–469

(
    seriesConfig,
    pointBuffer,
    pointCount,
    visibleStartIndex,
    visibleEndIndex,
    xScale,
    yScale,
    gridArea,
    rawBounds
  )

  };

  const prepare: ScatterDensityRenderer['prepare'] = (
    seriesConfig,
    pointBuffer,
    pointCount,
    visibleStartIndex,
    visibleEndIndex,
    xScale,
    yScale,
    gridArea,
    rawBounds
  ) => {
    assertNotDisposed();
    hasPrepared = true;

    const plotScissor = computePlotScissorDevicePx(gridArea);
    const dpr = gridArea.devicePixelRatio;
    const binSizeCss = Number.isFinite(seriesConfig.binSize) ? Math.max(1e-6, seriesConfig.binSize) : 2;
    const binSizePx = Math.max(1, Math.round(binSizeCss * (Number.isFinite(dpr) && dpr > 0 ? dpr : 1)));

    const binCountX = Math.max(1, Math.ceil(plotScissor.w / binSizePx));
    const binCountY = Math.max(1, Math.ceil(plotScissor.h / binSizePx));

    ensureBins(binCountX, binCountY);
    ensureLut(seriesConfig);

    const normU32 = normalizationToU32(seriesConfig.densityNormalization);

    // Dirty detection.
    if (lastPointBuffer !== pointBuffer) {
      lastPointBuffer = pointBuffer;
      computeBindGroup = null;
      renderBindGroup = null;
      computeDirty = true;
    }
    if (lastPointCount !== pointCount) {
      lastPointCount = pointCount;
      computeDirty = true;
    }
    if (lastVisibleStart !== visibleStartIndex || lastVisibleEnd !== visibleEndIndex) {
      lastVisibleStart = visibleStartIndex;
      lastVisibleEnd = visibleEndIndex;
      computeDirty = true;
    }
    if (lastBinSizePx !== binSizePx || lastBinCountX !== binCountX || lastBinCountY !== binCountY) {
      lastBinSizePx = binSizePx;
      lastBinCountX = binCountX;
      lastBinCountY = binCountY;
      computeDirty = true;
    }
    if (
      !lastPlotScissor ||
      lastPlotScissor.x !== plotScissor.x ||
      lastPlotScissor.y !== plotScissor.y ||
      lastPlotScissor.w !== plotScissor.w ||
      lastPlotScissor.h !== plotScissor.h
    ) {
      lastPlotScissor = plotScissor;
      computeDirty = true;