@playcanvas/splat-transform/dist/lib/spatial/radix-sort.d.ts

Library and CLI tool for 3D Gaussian splat format conversion and transformation

/**
 * Reusable scratch buffers for `radixSortIndicesByFloat`. One instance is
 * shared across many sort calls to avoid allocating multi-MB typed arrays on
 * every call. Buffers grow on demand and never shrink.
 *
 * Only two count-sized buffers are held; the third (encoded keys) is the
 * caller's `keys` buffer reinterpreted as u32 and encoded in place. That cuts
 * scratch from ~24 N bytes to ~16 N — at 143M edges it saves ~572 MB at peak.
 */
declare class RadixSortScratch {
    /** Ping-pong destination for u32 keys. */
    keysAlt: Uint32Array;
    /** Ping-pong destination for indices. */
    indicesAlt: Uint32Array;
    /** Per-byte histogram, reused across passes. */
    counts: Uint32Array;
    constructor();
    ensure(count: number): void;
}
/**
 * 4-pass LSD radix sort of `indices[0..count)` ascending by the Float32 value
 * at the parallel position in `keys`. Mutates `indices` in place.
 *
 * `keys[i]` is the sort key for `indices[i]` — the two arrays are parallel.
 * Callers compute both before calling and the sort permutes them together so
 * the parallel relationship is preserved on output.
 *
 * **`keys` is mutated**: its underlying buffer is reinterpreted as u32 and
 * monotonic-encoded in place to save the count-sized scratch buffer that an
 * out-of-place encode would need. Callers must treat the Float32 contents of
 * `keys` as garbage after this call.
 *
 * NaN / Inf entries are sorted to one extreme based on their bit pattern.
 * Callers that need to reject them should filter before calling. (At
 * ~250K-150M elements this is ~20x faster than a JavaScript comparator
 * sort.)
 *
 * @param indices - Integer payload, mutated in place.
 * @param keys - Float32 sort keys, parallel to `indices`. Mutated — contents are u32-encoded after this call; treat as garbage.
 * @param count - Number of valid entries (length of the parallel prefix).
 * @param scratch - Reusable scratch buffers; grown on demand.
 */
declare const radixSortIndicesByFloat: (indices: Uint32Array, keys: Float32Array, count: number, scratch: RadixSortScratch) => void;
/**
 * Test whether a Float32 bit pattern represents NaN or ±Inf.
 * Useful for callers that want to filter non-finite keys out before sorting.
 *
 * @param bits - Float32 bit pattern.
 * @returns true if the value is NaN or infinite.
 */
declare const isFloatBitsNonFinite: (bits: number) => boolean;
export { RadixSortScratch, radixSortIndicesByFloat, isFloatBitsNonFinite };