/**
 * LTTB (Largest-Triangle-Three-Buckets) Downsampling Algorithm
 *
 * This algorithm downsamples time-series data while preserving visual features.
 * It's much better than naive sampling for preserving peaks and valleys.
 *
 * Reference: https://skemman.is/bitstream/1946/15343/3/SS_MSthesis.pdf
 */
export interface DownsampleResult {
    x: Float32Array;
    y: Float32Array;
    /** Original indices of selected points */
    indices: Uint32Array;
}
/**
 * Downsample data using LTTB algorithm
 *
 * @param x - X values (e.g., potential)
 * @param y - Y values (e.g., current)
 * @param targetPoints - Number of output points
 * @returns Downsampled data
 */
export declare function lttbDownsample(x: Float32Array | Float64Array, y: Float32Array | Float64Array, targetPoints: number): DownsampleResult;
/**
 * Min-Max per bucket downsampling
 *
 * Simpler alternative to LTTB that preserves extremes in each bucket.
 * Uses 2 points per bucket (min and max), so output is ~2x target.
 */
export declare function minMaxDownsample(x: Float32Array | Float64Array, y: Float32Array | Float64Array, bucketCount: number): DownsampleResult;
/**
 * Calculate optimal target points based on canvas width
 */
export declare function calculateTargetPoints(dataLength: number, canvasWidth: number, pointsPerPixel?: number): number;
export interface OhlcDownsampleResult {
    x: Float32Array;
    open: Float32Array;
    high: Float32Array;
    low: Float32Array;
    close: Float32Array;
    indices: Uint32Array;
}
/**
 * Aggregate OHLC bars into fewer buckets while preserving extremes.
 * Each bucket: open=first open, close=last close, high=max high, low=min low, x=last x.
 */
export declare function ohlcMinMaxDownsample(x: Float32Array | Float64Array, open: Float32Array | Float64Array, high: Float32Array | Float64Array, low: Float32Array | Float64Array, close: Float32Array | Float64Array, targetBars: number): OhlcDownsampleResult;
/** Binary search lower bound: first index where x[i] >= value */
export declare function lowerBoundX(x: Float32Array | Float64Array, value: number): number;
/** Binary search upper bound: first index where x[i] > value */
export declare function upperBoundX(x: Float32Array | Float64Array, value: number): number;
export interface ViewportSlice {
    x: Float32Array;
    y?: Float32Array;
    open?: Float32Array;
    high?: Float32Array;
    low?: Float32Array;
    close?: Float32Array;
    start: number;
    end: number;
}
/**
 * Slice sorted x-series to visible range plus buffer (fraction of visible width).
 */
export declare function sliceSeriesToViewport(source: {
    x: Float32Array | Float64Array;
    y?: Float32Array | Float64Array;
    open?: Float32Array | Float64Array;
    high?: Float32Array | Float64Array;
    low?: Float32Array | Float64Array;
    close?: Float32Array | Float64Array;
}, xMin: number, xMax: number, bufferRatio?: number): ViewportSlice;