Files
vim-maze/src/MazeGenerator.ts
T
2025-10-14 13:33:51 +01:00

347 lines
8.4 KiB
TypeScript

import type { PositionTag, Coord, CellTag, MazeCell, MazeData } from "./types";
export class MazeGenerator {
width: number;
height: number;
cols: number;
rows: number;
maze: MazeCell[][];
totalSteps: number = 0;
constructor(userCols: number, userRows: number) {
const cellsWide = Math.max(1, Math.floor(userCols / 2));
const cellsHigh = Math.max(1, Math.floor(userRows / 2));
this.width = cellsWide;
this.height = cellsHigh;
this.cols = 2 * this.width + 1;
this.rows = 2 * this.height + 1;
this.maze = this.initArray<MazeCell>([]);
this.maze.forEach((row, r) => {
row.forEach((_cell, c) => {
switch (r) {
case 0:
case this.rows - 1:
this.maze[r][c] = ["wall"];
break;
default:
if ((r % 2) === 1) {
if ((c === 0) || (c === this.cols - 1)) {
this.maze[r][c] = ["wall"];
}
} else if (c % 2 === 0) {
this.maze[r][c] = ["wall"];
}
}
});
if (r === 0) {
const doorPos = this.posToSpace(this.rand(1, this.width));
this.maze[r][doorPos] = ["door", "exit"];
}
if (r === this.rows - 1) {
const doorPos = this.posToSpace(this.rand(1, this.width));
this.maze[r][doorPos] = ["door", "entrance"];
}
});
this.partition(1, this.height - 1, 1, this.width - 1);
}
private initArray<T = unknown>(value?: T): T[][] {
return new Array(this.rows)
.fill(null)
.map(() => new Array(this.cols).fill(value as T));
}
private rand(min: number, max: number): number {
return min + Math.floor(Math.random() * (1 + max - min));
}
private posToSpace(x: number): number {
return 2 * (x - 1) + 1;
}
private posToWall(x: number): number {
return 2 * x;
}
private inBounds(r: number, c: number): boolean {
if (
typeof this.maze[r] === "undefined" ||
typeof this.maze[r]?.[c] === "undefined"
) {
return false;
}
return true;
}
private shuffle<T>(array: T[]): T[] {
for (let i = array.length - 1; i > 0; i--) {
const j = Math.floor(Math.random() * (i + 1));
[array[i], array[j]] = [array[j], array[i]];
}
return array;
}
private partition(r1: number, r2: number, c1: number, c2: number): void {
let horiz: number, vert: number;
let x: number, y: number, start: number, end: number;
if (r2 < r1 || c2 < c1) {
return;
}
if (r1 === r2) {
horiz = r1;
} else {
x = r1 + 1;
y = r2 - 1;
start = Math.round(x + (y - x) / 4);
end = Math.round(x + (y - x) * 3 / 4);
horiz = this.rand(start, end);
}
if (c1 === c2) {
vert = c1;
} else {
x = c1 + 1;
y = c2 - 1;
start = Math.round(x + (y - x) / 3);
end = Math.round(x + (y - x) * 2 / 3);
vert = this.rand(start, end);
}
for (let i = this.posToWall(r1) - 1; i <= this.posToWall(r2) + 1; i++) {
for (let j = this.posToWall(c1) - 1; j <= this.posToWall(c2) + 1; j++) {
if (i === this.posToWall(horiz) || j === this.posToWall(vert)) {
this.maze[i][j] = ["wall"];
}
}
}
const gaps = this.shuffle([true, true, true, false]);
if (gaps[0]) {
const gapPosition = this.rand(c1, vert);
this.maze[this.posToWall(horiz)][this.posToSpace(gapPosition)] = [];
}
if (gaps[1]) {
const gapPosition = this.rand(vert + 1, c2 + 1);
this.maze[this.posToWall(horiz)][this.posToSpace(gapPosition)] = [];
}
if (gaps[2]) {
const gapPosition = this.rand(r1, horiz);
this.maze[this.posToSpace(gapPosition)][this.posToWall(vert)] = [];
}
if (gaps[3]) {
const gapPosition = this.rand(horiz + 1, r2 + 1);
this.maze[this.posToSpace(gapPosition)][this.posToWall(vert)] = [];
}
this.partition(r1, horiz - 1, c1, vert - 1);
this.partition(horiz + 1, r2, c1, vert - 1);
this.partition(r1, horiz - 1, vert + 1, c2);
this.partition(horiz + 1, r2, vert + 1, c2);
}
private isGap(...cells: Array<[number, number]>): boolean {
return cells.every(([row, col]) => {
const cell = this.maze[row][col];
if (cell.length > 0) {
if (!cell.includes("door")) return false;
}
return true;
});
}
private countSteps(
array: (number | undefined)[][],
r: number,
c: number,
val: number,
stop: CellTag
): boolean {
if (!this.inBounds(r, c)) {
return false;
}
if (array[r][c] !== undefined && (array[r][c] as number) <= val) {
return false;
}
if (!this.isGap([r, c])) {
return false;
}
array[r][c] = val;
if (this.maze[r][c].includes(stop)) {
return true;
}
this.countSteps(array, r - 1, c, val + 1, stop);
this.countSteps(array, r, c + 1, val + 1, stop);
this.countSteps(array, r + 1, c, val + 1, stop);
this.countSteps(array, r, c - 1, val + 1, stop);
return false;
}
private getKeyLocation(): Coord {
const fromEntrance = this.initArray<number | undefined>();
const fromExit = this.initArray<number | undefined>();
this.totalSteps = -1;
for (let j = 1; j < this.cols - 1; j++) {
if (this.maze[this.rows - 1][j].includes("entrance")) {
this.countSteps(fromEntrance, this.rows - 1, j, 0, "exit");
}
if (this.maze[0][j].includes("exit")) {
this.countSteps(fromExit, 0, j, 0, "entrance");
}
}
let fc = -1,
fr = -1;
this.maze.forEach((_row, r) => {
_row.forEach((_cell, c) => {
if (typeof fromEntrance[r]?.[c] === "undefined") {
return;
}
const stepCount =
(fromEntrance[r][c] ?? Infinity) + (fromExit[r][c] ?? Infinity);
if (stepCount > this.totalSteps) {
fr = r;
fc = c;
this.totalSteps = stepCount;
}
});
});
return [fr, fc];
}
placeKey(): void {
const [fr, fc] = this.getKeyLocation();
this.maze[fr][fc] = ["key"];
}
shortestPath(
fromTag: PositionTag,
toTag: PositionTag,
currentPosition?: Coord
): Coord[] {
let start: Coord | undefined;
let end: Coord | undefined;
if (fromTag === "hero" && currentPosition) {
start = currentPosition;
} else {
for (let r = 0; r < this.rows; r++) {
for (let c = 0; c < this.cols; c++) {
if (this.maze[r][c].includes(fromTag)) start = [r, c];
}
}
}
for (let r = 0; r < this.rows; r++) {
for (let c = 0; c < this.cols; c++) {
if (this.maze[r][c].includes(toTag)) end = [r, c];
}
}
if (!start || !end) return [];
const visited = this.initArray<boolean>(false);
const prev = this.initArray<Coord | null>(null);
const queue: Coord[] = [[...start]];
visited[start[0]][start[1]] = true;
const dirs: Coord[] = [
[-1, 0],
[1, 0],
[0, -1],
[0, 1],
];
while (queue.length > 0) {
const [r, c] = queue.shift() as Coord;
if (r === end[0] && c === end[1]) {
const path: Coord[] = [];
let curr: Coord | null = end;
while (curr) {
path.unshift(curr);
curr = prev[curr[0]][curr[1]];
}
return path;
}
for (const [dr, dc] of dirs) {
const nr = r + dr,
nc = c + dc;
if (!this.inBounds(nr, nc)) continue;
if (visited[nr][nc]) continue;
if (this.maze[nr][nc].includes("wall")) continue;
visited[nr][nc] = true;
prev[nr][nc] = [r, c];
queue.push([nr, nc]);
}
}
return [];
}
shortestPathToKey(currentPosition?: Coord): Coord[] {
return this.shortestPath(
currentPosition ? "hero" : "entrance",
"key",
currentPosition
);
}
shortestPathToExit(currentPosition?: Coord): Coord[] {
return this.shortestPath(
currentPosition ? "hero" : "entrance",
"exit",
currentPosition
);
}
getDistance(
fromTag: PositionTag,
toTag: PositionTag,
currentPosition?: Coord
): number {
const path = this.shortestPath(fromTag, toTag, currentPosition);
return path.length ? path.length - 1 : Infinity;
}
getData(): MazeData {
return {
maze: this.maze,
width: this.width,
height: this.height,
cols: this.cols,
rows: this.rows,
totalSteps: this.totalSteps,
};
}
toJSON(): MazeData {
return this.getData();
}
}