/**
 * 3D Raycasting utilities for picking/selection.
 * Implements ray-sphere intersection for bubble selection.
 */
export interface Ray3D {
    origin: [number, number, number];
    direction: [number, number, number];
}
export interface HitResult {
    index: number;
    distance: number;
    point: [number, number, number];
}
/**
 * Creates a ray from screen coordinates through the scene.
 * @param screenX Screen X coordinate (pixels from left)
 * @param screenY Screen Y coordinate (pixels from top)
 * @param canvasWidth Canvas width in pixels
 * @param canvasHeight Canvas height in pixels
 * @param viewProjectionMatrix Combined view-projection matrix
 * @returns Ray in world space
 */
export declare function createRayFromScreen(screenX: number, screenY: number, canvasWidth: number, canvasHeight: number, viewProjectionMatrix: Float32Array): Ray3D;
/**
 * Test ray-sphere intersection.
 * @param ray The ray to test
 * @param center Sphere center
 * @param radius Sphere radius
 * @returns Distance to intersection, or null if no hit
 */
export declare function raySphereIntersection(ray: Ray3D, center: [number, number, number], radius: number): number | null;
/**
 * Find the closest bubble hit by a ray.
 * @param ray The ray to test
 * @param positions Float32Array of positions (x,y,z interleaved)
 * @param scales Float32Array of scales (radii)
 * @param baseRadius Base radius multiplier
 * @returns Hit result or null if no hit
 */
export declare function pickBubble(ray: Ray3D, positions: Float32Array, scales: Float32Array, baseRadius?: number): HitResult | null;
/**
 * Batch pick bubbles - returns all bubbles within a tolerance of the ray.
 * More efficient for hover detection.
 */
export declare function pickBubblesInRange(ray: Ray3D, positions: Float32Array, scales: Float32Array, baseRadius?: number, maxResults?: number): HitResult[];
/**
 * Calculate distance from a point to a ray (for approximate/fast picking).
 */
export declare function pointToRayDistance(ray: Ray3D, point: [number, number, number]): number;
/**
 * Result of a surface mesh hit test
 */
export interface SurfaceHitResult {
    /** Distance from ray origin to hit point */
    distance: number;
    /** Hit point in world coordinates */
    point: [number, number, number];
    /** Grid row and column indices */
    row: number;
    col: number;
    /** Interpolated Y value at hit point */
    yValue: number;
    /** Barycentric coordinates for interpolation */
    baryU: number;
    baryV: number;
}
/**
 * Ray-triangle intersection using Möller-Trumbore algorithm.
 * Returns distance to intersection or null if no hit.
 */
export declare function rayTriangleIntersection(ray: Ray3D, v0: [number, number, number], v1: [number, number, number], v2: [number, number, number]): {
    distance: number;
    u: number;
    v: number;
} | null;
/**
 * Pick a point on a surface mesh grid.
 * Tests ray against all triangles in the grid.
 *
 * @param ray The picking ray
 * @param xValues X coordinates array (columns)
 * @param zValues Z coordinates array (rows)
 * @param yValues Y values array (row-major: row * cols + col)
 * @returns Hit result or null if no intersection
 */
export declare function pickSurfaceMesh(ray: Ray3D, xValues: Float32Array, zValues: Float32Array, yValues: Float32Array): SurfaceHitResult | null;
/**
 * Calculate the shortest distance between a ray and a line segment.
 * Useful for picking lines and thin tubes.
 */
export declare function raySegmentDistance(ray: Ray3D, p0: [number, number, number], p1: [number, number, number]): {
    distance: number;
    pointOnRay: [number, number, number];
    pointOnSegment: [number, number, number];
    t: number;
};
/**
 * Pick a series index and point index from a 3D line.
 */
export declare function pickLine(ray: Ray3D, lines: {
    x: Float32Array;
    y: Float32Array;
    z: Float32Array;
}[], threshold?: number): {
    seriesIndex: number;
    pointIndex: number;
    distance: number;
    point: [number, number, number];
} | null;
/**
 * Pick a point from an impulse/stem series.
 */
export declare function pickImpulse(ray: Ray3D, data: {
    x: Float32Array;
    y: Float32Array;
    z: Float32Array;
    baseY?: number;
}, threshold?: number): {
    index: number;
    distance: number;
    point: [number, number, number];
} | null;
/**
 * Pick a series index and point index from a 3D area (curtain).
 * Checks the top line of the area.
 */
export declare function pickArea(ray: Ray3D, areas: {
    x: Float32Array;
    y: Float32Array;
    z: Float32Array;
    baseY?: number;
}[], threshold?: number): {
    seriesIndex: number;
    pointIndex: number;
    distance: number;
    point: [number, number, number];
} | null;