roguelike-game/src/map_builders/dla.rs

use ::bracket_lib::prelude::*;

use super::common::{paint, Symmetry};
use crate::components::Position;
use crate::map_builders::{BuilderMap, InitialMapBuilder, MetaMapBuilder};
use crate::rng::roll_dice;
use crate::TileType;

#[derive(PartialEq, Copy, Clone)]
pub enum DLAAlgorithm {
    WalkInwards,
    WalkOutwards,
    CentralAttractor,
}

pub struct DLABuilder {
    algorithm: DLAAlgorithm,
    brush_size: i32,
    symmetry: Symmetry,
    floor_percent: f32,
}

impl InitialMapBuilder for DLABuilder {
    fn build_map(&mut self, build_data: &mut BuilderMap) {
        self.build(build_data);
    }
}

impl MetaMapBuilder for DLABuilder {
    fn build_map(&mut self, build_data: &mut BuilderMap) {
        self.build(build_data);
    }
}

impl DLABuilder {
    pub fn new() -> DLABuilder {
        DLABuilder {
            algorithm: DLAAlgorithm::WalkOutwards,
            brush_size: 1,
            symmetry: Symmetry::None,
            floor_percent: 0.25,
        }
    }

    pub fn walk_inwards() -> Box<DLABuilder> {
        Box::new(DLABuilder {
            algorithm: DLAAlgorithm::WalkInwards,
            ..DLABuilder::new()
        })
    }

    pub fn walk_outwards() -> Box<DLABuilder> {
        Box::new(DLABuilder {
            brush_size: 2,
            ..DLABuilder::new()
        })
    }

    pub fn central_attractor() -> Box<DLABuilder> {
        Box::new(DLABuilder {
            algorithm: DLAAlgorithm::CentralAttractor,
            brush_size: 2,
            ..DLABuilder::new()
        })
    }

    pub fn insectoid() -> Box<DLABuilder> {
        Box::new(DLABuilder {
            algorithm: DLAAlgorithm::CentralAttractor,
            brush_size: 2,
            symmetry: Symmetry::Horizontal,
            ..DLABuilder::new()
        })
    }

    #[allow(dead_code)]
    pub fn heavy_erosion() -> Box<DLABuilder> {
        Box::new(DLABuilder {
            algorithm: DLAAlgorithm::WalkInwards,
            brush_size: 2,
            floor_percent: 0.25,
            ..DLABuilder::new()
        })
    }

    #[allow(clippy::map_entry)]
    fn build(&mut self, build_data: &mut BuilderMap) {
        let starting_position = Position {
            x: build_data.map.width / 2,
            y: build_data.map.height / 2,
        };
        let start_idx = build_data
            .map
            .xy_idx(starting_position.x, starting_position.y);
        build_data.take_snapshot();

        // Carve a starting seed
        build_data.map.tiles[start_idx] = TileType::Floor;
        build_data.map.tiles[start_idx - 1] = TileType::Floor;
        build_data.map.tiles[start_idx + 1] = TileType::Floor;
        build_data.map.tiles[start_idx - build_data.map.width as usize] = TileType::Floor;
        build_data.map.tiles[start_idx + build_data.map.width as usize] = TileType::Floor;

        // Random walker
        let total_tiles = build_data.map.width * build_data.map.height;
        let desired_floor_tiles = (self.floor_percent * total_tiles as f32) as usize;
        let mut floor_tile_count = build_data
            .map
            .tiles
            .iter()
            .filter(|a| **a == TileType::Floor)
            .count();

        while floor_tile_count < desired_floor_tiles {
            match self.algorithm {
                DLAAlgorithm::WalkInwards => {
                    let mut digger_x = roll_dice(1, build_data.map.width - 3) + 1;
                    let mut digger_y = roll_dice(1, build_data.map.height - 3) + 1;
                    let mut prev_x = digger_x;
                    let mut prev_y = digger_y;
                    let mut digger_idx = build_data.map.xy_idx(digger_x, digger_y);

                    while build_data.map.tiles[digger_idx] == TileType::Wall {
                        prev_x = digger_x;
                        prev_y = digger_y;

                        let stagger_direction = roll_dice(1, 4);
                        match stagger_direction {
                            1 => {
                                if digger_x > 2 {
                                    digger_x -= 1;
                                }
                            }
                            2 => {
                                if digger_x < build_data.map.width - 2 {
                                    digger_x += 1
                                }
                            }
                            3 => {
                                if digger_y > 2 {
                                    digger_y -= 1
                                }
                            }
                            _ => {
                                if digger_y < build_data.map.height - 2 {
                                    digger_y += 1
                                }
                            }
                        }

                        digger_idx = build_data.map.xy_idx(digger_x, digger_y);
                    }

                    paint(
                        &mut build_data.map,
                        self.symmetry,
                        self.brush_size,
                        prev_x,
                        prev_y,
                    );
                }

                DLAAlgorithm::WalkOutwards => {
                    let mut digger_x = starting_position.x;
                    let mut digger_y = starting_position.y;
                    let mut digger_idx = build_data.map.xy_idx(digger_x, digger_y);

                    while build_data.map.tiles[digger_idx] == TileType::Floor {
                        let stagger_direction = roll_dice(1, 4);
                        match stagger_direction {
                            1 => {
                                if digger_x > 2 {
                                    digger_x -= 1;
                                }
                            }
                            2 => {
                                if digger_x < build_data.map.width - 2 {
                                    digger_x += 1
                                }
                            }
                            3 => {
                                if digger_y > 2 {
                                    digger_y -= 1
                                }
                            }
                            _ => {
                                if digger_y < build_data.map.height - 2 {
                                    digger_y += 1
                                }
                            }
                        }

                        digger_idx = build_data.map.xy_idx(digger_x, digger_y);
                    }

                    paint(
                        &mut build_data.map,
                        self.symmetry,
                        self.brush_size,
                        digger_x,
                        digger_y,
                    );
                }

                DLAAlgorithm::CentralAttractor => {
                    let mut digger_x = roll_dice(1, build_data.map.width - 3) + 1;
                    let mut digger_y = roll_dice(1, build_data.map.height - 3) + 1;
                    let mut prev_x = digger_x;
                    let mut prev_y = digger_y;
                    let mut digger_idx = build_data.map.xy_idx(digger_x, digger_y);

                    let mut path = line2d(
                        LineAlg::Bresenham,
                        Point::new(digger_x, digger_y),
                        Point::new(starting_position.x, starting_position.y),
                    );

                    while build_data.map.tiles[digger_idx] == TileType::Wall && !path.is_empty() {
                        prev_x = digger_x;
                        prev_y = digger_y;
                        digger_x = path[0].x;
                        digger_y = path[0].y;
                        path.remove(0);
                        digger_idx = build_data.map.xy_idx(digger_x, digger_y);
                    }

                    paint(
                        &mut build_data.map,
                        self.symmetry,
                        self.brush_size,
                        prev_x,
                        prev_y,
                    );
                }
            }

            build_data.take_snapshot();

            floor_tile_count = build_data
                .map
                .tiles
                .iter()
                .filter(|a| **a == TileType::Floor)
                .count();
        }
    }
}