roguelike-game/src/map_builders/maze.rs
2021-12-14 14:15:22 -05:00

288 lines
7.7 KiB
Rust

use std::cmp::{max, min};
use std::collections::HashMap;
use rltk::RandomNumberGenerator;
use super::{
generate_voronoi_spawn_regions, remove_unreachable_areas_returning_most_distant, MapBuilder,
};
use crate::{spawner, Map, Position, TileType, SHOW_MAPGEN_VISUALIZER};
pub struct MazeBuilder {
map: Map,
starting_position: Position,
depth: i32,
history: Vec<Map>,
noise_areas: HashMap<i32, Vec<usize>>,
spawn_list: Vec<(usize, String)>,
}
impl MapBuilder for MazeBuilder {
fn get_map(&self) -> Map {
self.map.clone()
}
fn get_starting_position(&self) -> Position {
self.starting_position
}
fn get_snapshot_history(&self) -> Vec<Map> {
self.history.clone()
}
fn build_map(&mut self) {
self.build();
}
fn take_snapshot(&mut self) {
if SHOW_MAPGEN_VISUALIZER {
let mut snapshot = self.map.clone();
for v in snapshot.revealed_tiles.iter_mut() {
*v = true;
}
self.history.push(snapshot);
}
}
fn get_spawn_list(&self) -> &Vec<(usize, String)> {
&self.spawn_list
}
}
impl MazeBuilder {
pub fn new(new_depth: i32) -> MazeBuilder {
MazeBuilder {
map: Map::new(new_depth),
starting_position: Position::default(),
depth: new_depth,
history: Vec::new(),
noise_areas: HashMap::new(),
spawn_list: Vec::new(),
}
}
#[allow(clippy::map_entry)]
fn build(&mut self) {
let mut rng = RandomNumberGenerator::new();
// Maze gen
let mut maze = Grid::new(
(self.map.width / 2) - 2,
(self.map.height / 2) - 2,
&mut rng,
);
maze.generate_maze(self);
self.starting_position = Position { x: 2, y: 2 };
let start_idx = self
.map
.xy_idx(self.starting_position.x, self.starting_position.y);
self.take_snapshot();
// Find all tiles we can reach from the starting point
let exit_tile = remove_unreachable_areas_returning_most_distant(&mut self.map, start_idx);
self.take_snapshot();
// Place the stairs
self.map.tiles[exit_tile] = TileType::DownStairs;
self.take_snapshot();
// Now we build a noise map for use in spawning entities later
self.noise_areas = generate_voronoi_spawn_regions(&self.map, &mut rng);
// Spawn the entities
for area in self.noise_areas.iter() {
spawner::spawn_region(
&self.map,
&mut rng,
area.1,
self.depth,
&mut self.spawn_list,
);
}
}
}
const TOP: usize = 0;
const RIGHT: usize = 1;
const BOTTOM: usize = 2;
const LEFT: usize = 3;
#[derive(Copy, Clone)]
struct Cell {
row: i32,
column: i32,
walls: [bool; 4],
visited: bool,
}
impl Cell {
fn new(row: i32, column: i32) -> Cell {
Cell {
row,
column,
walls: [true, true, true, true],
visited: false,
}
}
fn remove_walls(&mut self, next: &mut Cell) {
let x = self.column - next.column;
let y = self.row - next.row;
if x == 1 {
self.walls[LEFT] = false;
next.walls[RIGHT] = false;
} else if x == -1 {
self.walls[RIGHT] = false;
next.walls[LEFT] = false;
} else if y == 1 {
self.walls[TOP] = false;
next.walls[BOTTOM] = false;
} else if y == -1 {
self.walls[BOTTOM] = false;
next.walls[TOP] = false;
}
}
}
struct Grid<'a> {
width: i32,
height: i32,
cells: Vec<Cell>,
backtrace: Vec<usize>,
current: usize,
rng: &'a mut RandomNumberGenerator,
}
impl<'a> Grid<'a> {
fn new(width: i32, height: i32, rng: &mut RandomNumberGenerator) -> Grid {
let mut grid = Grid {
width,
height,
cells: Vec::new(),
backtrace: Vec::new(),
current: 0,
rng,
};
for row in 0..height {
for column in 0..width {
grid.cells.push(Cell::new(row, column));
}
}
grid
}
fn calculate_index(&self, row: i32, column: i32) -> i32 {
if row < 0 || column < 0 || column > self.width - 1 || row > self.height - 1 {
-1
} else {
column + (row * self.width)
}
}
fn get_available_neighbors(&self) -> Vec<usize> {
let mut neighbors: Vec<usize> = Vec::new();
let current_row = self.cells[self.current].row;
let current_column = self.cells[self.current].column;
let neighbor_indices: [i32; 4] = [
self.calculate_index(current_row - 1, current_column),
self.calculate_index(current_row, current_column + 1),
self.calculate_index(current_row + 1, current_column),
self.calculate_index(current_row, current_column - 1),
];
for i in neighbor_indices.iter() {
if *i != -1 && !self.cells[*i as usize].visited {
neighbors.push(*i as usize);
}
}
neighbors
}
fn find_next_cell(&mut self) -> Option<usize> {
let neighbors = self.get_available_neighbors();
if !neighbors.is_empty() {
return if neighbors.len() == 1 {
Some(neighbors[0])
} else {
Some(neighbors[(self.rng.roll_dice(1, neighbors.len() as i32) - 1) as usize])
};
}
None
}
fn generate_maze(&mut self, generator: &mut MazeBuilder) {
let mut i = 0;
loop {
self.cells[self.current].visited = true;
match self.find_next_cell() {
Some(next) => {
self.cells[next].visited = true;
self.backtrace.push(self.current);
// __lower_part__ __higher_part_
// / \ / \
// --------cell1------ | cell2-----------
let (lower_part, higher_part) =
self.cells.split_at_mut(max(self.current, next));
let cell1 = &mut lower_part[min(self.current, next)];
let cell2 = &mut higher_part[0];
cell1.remove_walls(cell2);
self.current = next;
}
None => {
if !self.backtrace.is_empty() {
self.current = self.backtrace[0];
self.backtrace.remove(0);
} else {
break;
}
}
}
if i % 50 == 0 {
self.copy_to_map(&mut generator.map);
generator.take_snapshot();
}
i += 1;
}
}
fn copy_to_map(&self, map: &mut Map) {
// Clear the map
for i in map.tiles.iter_mut() {
*i = TileType::Wall;
}
for cell in self.cells.iter() {
let x = cell.column + 1;
let y = cell.row + 1;
let idx = map.xy_idx(x * 2, y * 2);
map.tiles[idx] = TileType::Floor;
if !cell.walls[TOP] {
map.tiles[idx - map.width as usize] = TileType::Floor;
}
if !cell.walls[RIGHT] {
map.tiles[idx + 1] = TileType::Floor
}
if !cell.walls[BOTTOM] {
map.tiles[idx + map.width as usize] = TileType::Floor
}
if !cell.walls[LEFT] {
map.tiles[idx - 1] = TileType::Floor
}
}
}
}