Function interpolateSeriesForUpdate

src/core/createRenderCoordinator.ts:1653–1707

(
    fromSeries: ResolvedChartGPUOptions['series'],
    toSeries: ResolvedChartGPUOptions['series'],
    t01: number,
    caches: UpdateInterpolationCaches | null
  )

  };

  const interpolateSeriesForUpdate = (
    fromSeries: ResolvedChartGPUOptions['series'],
    toSeries: ResolvedChartGPUOptions['series'],
    t01: number,
    caches: UpdateInterpolationCaches | null
  ): ResolvedChartGPUOptions['series'] => {
    if (fromSeries.length !== toSeries.length) return toSeries;

    const out: ResolvedChartGPUOptions['series'][number][] = new Array(toSeries.length);

    for (let i = 0; i < toSeries.length; i++) {
      const a = fromSeries[i]!;
      const b = toSeries[i]!;

      if (a.type !== b.type) {
        out[i] = b;
        continue;
      }

      if (b.type === 'pie') {
        const cache = caches?.pieDataBySeriesIndex[i] ?? null;
        const animated = interpolatePieSeriesByIndex(a as ResolvedPieSeriesConfig, b as ResolvedPieSeriesConfig, t01, cache);
        if (caches) caches.pieDataBySeriesIndex[i] = animated.data as any;
        out[i] = animated;
        continue;
      }

      // Cartesian series: interpolate y-values by index. Keep x from "to".
      const aAny = a as unknown as { readonly data: ReadonlyArray<DataPoint> };
      const bAny = b as unknown as { readonly data: ReadonlyArray<DataPoint> };
      const aData = aAny.data;
      const bData = bAny.data;

      if (aData.length !== bData.length) {
        out[i] = b;
        continue;
      }
      if (bData.length > MAX_ANIMATED_POINTS_PER_SERIES) {
        out[i] = b;
        continue;
      }

      const cache = caches?.cartesianDataBySeriesIndex[i] ?? null;
      const animatedData = interpolateCartesianSeriesDataByIndex(aData, bData, t01, cache);
      if (!animatedData) {
        out[i] = b;
        continue;
      }
      if (caches) caches.cartesianDataBySeriesIndex[i] = animatedData;

      out[i] = { ...(b as any), data: animatedData };
    }

    return out;
  };

  const computeUpdateSnapshotAtProgress = (
    transition: UpdateTransition,