import type { TSLFloatNode, TSLIntNode, TSLNode, TSLStorageNode, TSLUintNode, TSLUVec2Node, TSLVec3Node, TSLVec4Node } from '../../types/tsl.js';
export type MPMIVec3Node = TSLNode<'ivec3'>;
export type MPMIVec4Node = TSLNode<'ivec4'>;
export type MPMGridIndexNode = TSLIntNode | TSLUintNode;
export type MPMGridContributionMode = 'atomic' | 'subgroup';
export type MPMPackedGridMirrorStorageNode = TSLStorageNode<'uvec2'>;
export type MPMUnpackedGridMirrorStorageNode = TSLStorageNode<'vec4'>;
export type MPMGridMirrorStorageNode = MPMPackedGridMirrorStorageNode | MPMUnpackedGridMirrorStorageNode;
/** Array-like vec3 weights retained after naming the TSL array expression. */
export interface MPMStencilWeightsNode {
    readonly isNode: true;
    element(index: TSLIntNode | number): TSLVec3Node;
}
export interface MPMQuadraticBSplineResult {
    cellIndex: MPMIVec3Node;
    weights: MPMStencilWeightsNode;
}
export interface MPMStencilTap {
    x: TSLIntNode;
    y: TSLIntNode;
    z: TSLIntNode;
    weight: TSLFloatNode;
    cell: MPMIVec3Node;
    distance: TSLVec3Node;
}
export type MPMStencilCallback = (tap: MPMStencilTap) => void;
/** Atomic grid struct member access used by P2G accumulation. */
export interface MPMGridAtomicTargetNode {
    get(field: 'x' | 'y' | 'z' | 'mass'): TSLIntNode;
}
/** Quadratic B-spline base cell and the three axis weights used by MLS-MPM. */
export declare function mpmQuadraticBSpline(gridPosition: TSLVec3Node): MPMQuadraticBSplineResult;
/** Flatten an XYZ grid coordinate using the solver's X-major layout. */
export declare function mpmCellPointer(cell: MPMIVec3Node, gridSize: TSLVec3Node): TSLIntNode;
/** Decode an X-major flattened grid pointer back to XYZ coordinates. */
export declare function mpmDecodeCellPointer(pointer: MPMGridIndexNode, gridSize: TSLVec3Node): MPMIVec3Node;
/**
 * Emit the 27 quadratic-stencil taps. The prefix is part of generated variable
 * names, so one kernel may safely invoke this helper more than once.
 */
export declare function forEachMPMStencil(prefix: string, weights: MPMStencilWeightsNode, cellIndex: MPMIVec3Node, gridPosition: TSLVec3Node, callback: MPMStencilCallback): void;
/**
 * @param {import('../../types/tsl.js').TSLVec4Node} value
 * @returns {import('../../types/tsl.js').TSLUVec2Node}
 */
export declare function packMPMGridMirror(value: TSLVec4Node): TSLUVec2Node;
/**
 * @param {import('../../types/tsl.js').TSLUVec2Node} value
 * @returns {import('../../types/tsl.js').TSLVec4Node}
 */
export declare function unpackMPMGridMirror(value: TSLUVec2Node): TSLVec4Node;
export declare function readMPMGridMirror(buffer: MPMPackedGridMirrorStorageNode, index: MPMGridIndexNode, packed: true): TSLVec4Node;
export declare function readMPMGridMirror(buffer: MPMUnpackedGridMirrorStorageNode, index: MPMGridIndexNode, packed: false): TSLVec4Node;
export declare function readMPMGridMirror(buffer: MPMGridMirrorStorageNode, index: MPMGridIndexNode, packed: boolean): TSLVec4Node;
export declare function writeMPMGridMirror(buffer: MPMPackedGridMirrorStorageNode, index: MPMGridIndexNode, value: TSLVec4Node, packed: true): void;
export declare function writeMPMGridMirror(buffer: MPMUnpackedGridMirrorStorageNode, index: MPMGridIndexNode, value: TSLVec4Node, packed: false): void;
export declare function writeMPMGridMirror(buffer: MPMGridMirrorStorageNode, index: MPMGridIndexNode, value: TSLVec4Node, packed: boolean): void;
/**
 * Add one P2G contribution. In subgroup mode, adjacent equal-cell lanes form a
 * segmented inclusive scan and only the segment tail performs global atomics.
 * The operation remains exact because the scan combines already-encoded i32s.
 */
export declare function addMPMGridContribution(target: MPMGridAtomicTargetNode, targetIndex: MPMGridIndexNode, momentum: MPMIVec3Node, mass: TSLIntNode, mode?: MPMGridContributionMode): void;