@openhps/core/dist/esm/three/nodes/core/StructNode.js

Open Hybrid Positioning System - Core component

import Node from './Node.js';
import StructTypeNode from './StructTypeNode.js';
import { nodeObject } from '../tsl/TSLCore.js';

/**
 * StructNode allows to create custom structures with multiple members.
 * This can also be used to define structures in attribute and uniform data.
 *
 * ```js
 * // Define a custom struct
 * const BoundingBox = struct( { min: 'vec3', max: 'vec3' } );
 *
 * // Create a new instance of the struct
 * const bb = BoundingBox( vec3( 0 ), vec3( 1 ) ); // style 1
 * const bb = BoundingBox( { min: vec3( 0 ), max: vec3( 1 ) } ); // style 2
 *
 * // Access the struct members
 * const min = bb.get( 'min' );
 *
 * // Assign a new value to a member
 * min.assign( vec3() );
 * ```
 * @augments Node
 */
class StructNode extends Node {
  static get type() {
    return 'StructNode';
  }
  constructor(structLayoutNode, values) {
    super('vec3');
    this.structLayoutNode = structLayoutNode;
    this.values = values;
    this.isStructNode = true;
  }
  getNodeType(builder) {
    return this.structLayoutNode.getNodeType(builder);
  }
  getMemberType(builder, name) {
    return this.structLayoutNode.getMemberType(builder, name);
  }
  generate(builder) {
    const nodeVar = builder.getVarFromNode(this);
    const structType = nodeVar.type;
    const propertyName = builder.getPropertyName(nodeVar);
    builder.addLineFlowCode(`${propertyName} = ${builder.generateStruct(structType, this.structLayoutNode.membersLayout, this.values)}`, this);
    return nodeVar.name;
  }
}
export default StructNode;

/**
 * TSL function for creating a struct node.
 *
 * @tsl
 * @function
 * @param {Object} membersLayout - The layout of the struct members.
 * @param {?string} [name=null] - The name of the struct.
 * @returns {Function} The struct function.
 */
export const struct = (membersLayout, name = null) => {
  const structLayout = new StructTypeNode(membersLayout, name);
  const struct = (...params) => {
    let values = null;
    if (params.length > 0) {
      if (params[0].isNode) {
        values = {};
        const names = Object.keys(membersLayout);
        for (let i = 0; i < params.length; i++) {
          values[names[i]] = params[i];
        }
      } else {
        values = params[0];
      }
    }
    return nodeObject(new StructNode(structLayout, values));
  };
  struct.layout = structLayout;
  struct.isStruct = true;
  return struct;
};