/**
 * Prepare bar chart data for WebGL rendering
 * Creates rectangle vertices for each bar (2 triangles per bar = 6 vertices)
 *
 * @param x - X positions of bar centers
 * @param y - Y heights of bars
 * @param barWidth - Width of each bar in data units
 * @returns Interleaved vertex data ready for gl.TRIANGLES
 */
export declare function interleaveBarData(x: Float32Array | Float64Array | number[], y: Float32Array | Float64Array | number[], barWidth: number): Float32Array;
/**
 * Calculate automatic bar width based on data spacing
 */
export declare function calculateBarWidth(x: Float32Array | Float64Array | number[]): number;