Function computeZoomAwareTarget

examples/million-points/main.ts:119–134

(baseThreshold: number, spanFrac: number)

 * Target grows ~ 1/spanFrac but capped to prevent excessive memory.
 */
const computeZoomAwareTarget = (baseThreshold: number, spanFrac: number): number => {
  // Mirrors createRenderCoordinator’s behavior (see examples/sampling/main.ts):
  // - 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));

  const v = Math.round(baseT / spanFracSafe);
  return clamp(v | 0, MIN_TARGET_POINTS, maxTarget);
};

/**
 * Estimates points rendered after sampling.