P5.js Maze Generator

sketch.js

const mapWidth = 50;
const mapHeight = 50;
const path = [];
const stack = [];
const map = [];
let currentIndex = 0;
let mazeGenFinished = false;
let gridSizeX = 10;
let gridSizeY = 10;

function setup() {
    createCanvas(1000, 1000);
    gridSizeX = width / mapWidth;
    gridSizeY = height / mapHeight;
    generateMap();
    // frameRate(10);
}

function draw() {
    background(245);
    renderMap();
    if (!mazeGenFinished) {
        for (let i = 0; i < 5; i++) {
            iterate();
        }
        let x = currentIndex % mapWidth;
        let y = Math.floor(currentIndex / mapWidth);
        fill(255, 0, 0);
        ellipse(
            x * gridSizeX + gridSizeX / 2,
            y * gridSizeY + gridSizeY / 2,
            gridSizeX / 2,
            gridSizeY / 2
        );
    }
}

function generateMap() {
    for (let i = 0; i < mapWidth * mapHeight; i++) {
        map[i] = [true, true, true, true];
    }
}

function renderMap() {
    strokeWeight(2);
    stroke(0);

    for (let i = 0; i < map.length; i++) {
        // Render four walls
        let x = i % mapWidth;
        let y = Math.floor(i / mapWidth);

        if (map[i][0]) {
            line(
                x * gridSizeX,
                y * gridSizeY,
                (x + 1) * gridSizeX,
                y * gridSizeY
            );
        }
        if (map[i][1]) {
            line(
                (x + 1) * gridSizeX,
                y * gridSizeY,
                (x + 1) * gridSizeX,
                (y + 1) * gridSizeY
            );
        }
        if (map[i][2]) {
            line(
                x * gridSizeX,
                (y + 1) * gridSizeY,
                (x + 1) * gridSizeX,
                (y + 1) * gridSizeY
            );
        }
        if (map[i][3]) {
            line(
                x * gridSizeX,
                y * gridSizeY,
                x * gridSizeX,
                (y + 1) * gridSizeY
            );
        }
    }
}

function getAvaliableSpaces(index) {
    let result = [];
    if ((index + 1) % mapWidth !== 0) result.push(index + 1);
    if (index % mapWidth !== 0) result.push(index - 1);
    if (index >= mapWidth) result.push(index - mapWidth);
    if (index < (mapHeight - 1) * mapWidth) result.push(index + mapHeight);
    result = result.filter(i => !path.includes(i));
    return result;
}

function iterate() {
    if (mazeGenFinished) return;
    let spaces = getAvaliableSpaces(currentIndex);
    if (spaces.length <= 0) {
        if (path.length === map.length) {
            mazeGenFinished = true;
        } else {
            stack.pop();
            currentIndex = stack[stack.length - 1];
        }
    } else {
        let randomPos = spaces[floor(random(0, spaces.length))];
        path.push(randomPos);
        stack.push(randomPos);
        map[currentIndex][
            getWallIndexFromDir(randomPos - currentIndex)
        ] = false;
        map[randomPos][getWallIndexFromDir(currentIndex - randomPos)] = false;
        currentIndex = randomPos;
    }
}

function getWallIndexFromDir(dir) {
    switch (dir) {
        case 1:
            return 1;
        case -1:
            return 3;
        case mapWidth:
            return 2;
        case -mapWidth:
            return 0;

        default:
            return 0;
    }
}