/**
 * HDR environment map light source detection.
 *
 * Analyzes equirectangular HDR pixel data to find dominant light sources
 * (softboxes in studio HDRs, sun in outdoor HDRs). Returns direction,
 * intensity, and color for up to 2 lights, used to create shadow-casting
 * DirectionalLights in Studio mode.
 *
 * Algorithm: downsample to 128x64 luminance grid → threshold at 10x median
 * → flood-fill cluster → convert centroids to 3D direction vectors.
 * Runs ~5-10ms on CPU, no GPU readback needed.
 */
/** A detected dominant light source from HDR analysis. */
export interface DetectedLight {
    /** Unit direction vector toward the light source (Y-up, before Z-up rotation). */
    direction: [number, number, number];
    /** Relative intensity (normalized, 0-1 range). */
    intensity: number;
    /** Linear RGB color of the light source (0-1 range). */
    color: [number, number, number];
}
/** Result of light detection analysis. */
export interface LightDetectionResult {
    /** Detected light sources (0-2 entries). */
    lights: DetectedLight[];
    /** Whether the result came from actual HDR analysis (true) or a fallback (false). */
    wasAnalyzed: boolean;
}
/**
 * Detect dominant light sources from equirectangular HDR pixel data.
 *
 * @param data - Raw pixel data (Uint16Array for HalfFloat, or Float32Array)
 * @param width - HDR image width in pixels
 * @param height - HDR image height in pixels
 * @returns Detection result with up to 2 lights
 */
export declare function detectDominantLights(data: Uint16Array | Float32Array, width: number, height: number): LightDetectionResult;
/**
 * Return hardcoded fallback lights for procedural RoomEnvironment.
 *
 * The RoomEnvironment has no raw HDR data to analyze. A single top-front
 * light direction approximates its primary illumination.
 */
export declare function getDefaultLights(): LightDetectionResult;