Function computeZoomAwareTarget

examples/sampling/main.ts:120–133

(baseThreshold: number, spanFrac: number)

const formatPercent = (n: number): string => `${n.toFixed(2)}%`;

const computeZoomAwareTarget = (baseThreshold: number, spanFrac: number): number => {
  // Mirrors createRenderCoordinator’s behavior:
  // - baseline target is samplingThreshold at full span
  // - zooming in increases target ~ 1/spanFrac
  // - capped to avoid pathological allocations
  const MIN_TARGET_POINTS = 2;
  const MAX_TARGET_POINTS_ABS = 200_000;
  const MAX_TARGET_MULTIPLIER = 32;
  const spanFracSafe = Math.max(1e-3, Math.min(1, spanFrac));

  const baseT = Number.isFinite(baseThreshold) ? Math.max(1, baseThreshold | 0) : 1;
  const maxTarget = Math.min(MAX_TARGET_POINTS_ABS, Math.max(MIN_TARGET_POINTS, baseT * MAX_TARGET_MULTIPLIER));
  return clampInt(Math.round(baseT / spanFracSafe), MIN_TARGET_POINTS, maxTarget);
};

const updateReadouts = (
  rawPointCount: number,