@nichathan-gaming/map-generator/mapGenerator/wilsonsGenerator/wilsonsGenerator.js

Creates and generates a 2 dimensional array with various path generation functions.

import mapGenerator from '../mapGenerator.js';
import walk from './walk.js';
import getAvailableIndexes from './getAvailableIndexes.js';
import firstWalk from './firstWalk.js';
import assertIndex from '../helpers/assertIndex.js';
import {assertInstanceOf, assertType, basicTypes} from '@nichathan-gaming/assertions';

/**
 * Generates a path through the map 
 * using Wilson's algorithm : Wikipedia Link : https://en.wikipedia.org/wiki/Loop-erased_random_walk
 * @param {mapGenerator} map The current game map element
 * @param {number} maxPathSize The maximum size for the path
 * @param {[number, number]} startIndex The index that the path begins at
 * @param {T} possiblePathValue A temporary value that denotes a part of the map that may be the next path
 */
const wilsonsGenerator = (map, maxPathSize, startIndex, possiblePathValue) => {
    assertInstanceOf(map, mapGenerator);
    assertType(maxPathSize, basicTypes.number);
    assertIndex(startIndex);
    map.assertBasicType(possiblePathValue);

    //create the main path for the map
    firstWalk(map, maxPathSize, startIndex, possiblePathValue);

    //track the badIndexes that cannot be added to the main path so they can be ignored
    const badIndexes = [];

    //Get the next indexes that can be moved on
    let nextIndexes = getAvailableIndexes(map, badIndexes);

    //While we can start a new path, start a new path and see if the indexes can be added to the main path
    while(nextIndexes.length > 0){
        //perform the next walk and grab the indexes that cannot be added to a path
        const foundBadIndexes = walk(map, maxPathSize, nextIndexes[0], possiblePathValue);

        //we have found some indexes that cannot be added to the main path, save them so we don't keep going there
        if(foundBadIndexes.length > 0){
            badIndexes.push(...foundBadIndexes);
        };

        //get the next indexes that can be moved on
        nextIndexes = getAvailableIndexes(map, badIndexes);
    };
};

export default wilsonsGenerator;