rust-roguelike-tutorial/chapter-29-mazes/src/spawner.rs

extern crate rltk;
use rltk::{ RGB, RandomNumberGenerator };
extern crate specs;
use specs::prelude::*;
use super::{CombatStats, Player, Renderable, Name, Position, Viewshed, Monster, BlocksTile, Rect, Item, 
    Consumable, Ranged, ProvidesHealing, map::MAPWIDTH, InflictsDamage, AreaOfEffect, Confusion, SerializeMe,
    random_table::RandomTable, EquipmentSlot, Equippable, MeleePowerBonus, DefenseBonus, HungerClock,
    HungerState, ProvidesFood, MagicMapper, Hidden, EntryTrigger, SingleActivation, Map, TileType };
use crate::specs::saveload::{MarkedBuilder, SimpleMarker};
use std::collections::HashMap;

/// Spawns the player and returns his/her entity object.
pub fn player(ecs : &mut World, player_x : i32, player_y : i32) -> Entity {
    ecs
        .create_entity()
        .with(Position { x: player_x, y: player_y })
        .with(Renderable {
            glyph: rltk::to_cp437('@'),
            fg: RGB::named(rltk::YELLOW),
            bg: RGB::named(rltk::BLACK),
            render_order: 0
        })
        .with(Player{})
        .with(Viewshed{ visible_tiles : Vec::new(), range: 8, dirty: true })
        .with(Name{name: "Player".to_string() })
        .with(CombatStats{ max_hp: 30, hp: 30, defense: 2, power: 5 })
        .with(HungerClock{ state: HungerState::WellFed, duration: 20 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build()
}

const MAX_MONSTERS : i32 = 4;

fn room_table(map_depth: i32) -> RandomTable {
    RandomTable::new()
        .add("Goblin", 10)
        .add("Orc", 1 + map_depth)
        .add("Health Potion", 7)
        .add("Fireball Scroll", 2 + map_depth)
        .add("Confusion Scroll", 2 + map_depth)
        .add("Magic Missile Scroll", 4)
        .add("Dagger", 3)
        .add("Shield", 3)
        .add("Longsword", map_depth - 1)
        .add("Tower Shield", map_depth - 1)
        .add("Rations", 10)
        .add("Magic Mapping Scroll", 2)
        .add("Bear Trap", 5)
}

/// Fills a room with stuff!
pub fn spawn_room(ecs: &mut World, room : &Rect, map_depth: i32) {
    let mut possible_targets : Vec<usize> = Vec::new();
    { // Borrow scope - to keep access to the map separated
        let map = ecs.fetch::<Map>();
        for y in room.y1 + 1 .. room.y2 {
            for x in room.x1 + 1 .. room.x2 {
                let idx = map.xy_idx(x, y);
                if map.tiles[idx] == TileType::Floor {
                    possible_targets.push(idx);
                }
            }
        }
    }

    spawn_region(ecs, &possible_targets, map_depth);
}

/// Fills a region with stuff!
pub fn spawn_region(ecs: &mut World, area : &[usize], map_depth: i32) {
    let spawn_table = room_table(map_depth);
    let mut spawn_points : HashMap<usize, String> = HashMap::new();
    let mut areas : Vec<usize> = Vec::from(area);

    // Scope to keep the borrow checker happy
    {
        let mut rng = ecs.write_resource::<RandomNumberGenerator>();
        let num_spawns = i32::min(areas.len() as i32, rng.roll_dice(1, MAX_MONSTERS + 3) + (map_depth - 1) - 3);
        if num_spawns == 0 { return; }

        for _i in 0 .. num_spawns {
            let array_index = if areas.len() == 1 { 0usize } else { (rng.roll_dice(1, areas.len() as i32)-1) as usize };

            let map_idx = areas[array_index];
            spawn_points.insert(map_idx, spawn_table.roll(&mut rng));
            areas.remove(array_index);
        }
    }

    // Actually spawn the monsters
    for spawn in spawn_points.iter() {
        spawn_entity(ecs, &spawn);
    }
}

/// Spawns a named entity (name in tuple.1) at the location in (tuple.0)
fn spawn_entity(ecs: &mut World, spawn : &(&usize, &String)) {
    let x = (*spawn.0 % MAPWIDTH) as i32;
    let y = (*spawn.0 / MAPWIDTH) as i32;

    match spawn.1.as_ref() {
        "Goblin" => goblin(ecs, x, y),
        "Orc" => orc(ecs, x, y),
        "Health Potion" => health_potion(ecs, x, y),
        "Fireball Scroll" => fireball_scroll(ecs, x, y),
        "Confusion Scroll" => confusion_scroll(ecs, x, y),
        "Magic Missile Scroll" => magic_missile_scroll(ecs, x, y),
        "Dagger" => dagger(ecs, x, y),
        "Shield" => shield(ecs, x, y),
        "Longsword" => longsword(ecs, x, y),
        "Tower Shield" => tower_shield(ecs, x, y),
        "Rations" => rations(ecs, x, y),
        "Magic Mapping Scroll" => magic_mapping_scroll(ecs, x, y),
        "Bear Trap" => bear_trap(ecs, x, y),
        _ => {}
    }
}

fn orc(ecs: &mut World, x: i32, y: i32) { monster(ecs, x, y, rltk::to_cp437('o'), "Orc"); }
fn goblin(ecs: &mut World, x: i32, y: i32) { monster(ecs, x, y, rltk::to_cp437('g'), "Goblin"); }

fn monster<S : ToString>(ecs: &mut World, x: i32, y: i32, glyph : u8, name : S) {
    ecs.create_entity()
        .with(Position{ x, y })
        .with(Renderable{
            glyph,
            fg: RGB::named(rltk::RED),
            bg: RGB::named(rltk::BLACK),
            render_order: 1
        })
        .with(Viewshed{ visible_tiles : Vec::new(), range: 8, dirty: true })
        .with(Monster{})
        .with(Name{ name : name.to_string() })
        .with(BlocksTile{})
        .with(CombatStats{ max_hp: 16, hp: 16, defense: 1, power: 4 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn health_potion(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position{ x, y })
        .with(Renderable{
            glyph: rltk::to_cp437('¡'),
            fg: RGB::named(rltk::MAGENTA),
            bg: RGB::named(rltk::BLACK),
            render_order: 2
        })
        .with(Name{ name : "Health Potion".to_string() })
        .with(Item{})
        .with(Consumable{})
        .with(ProvidesHealing{ heal_amount: 8 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn magic_missile_scroll(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position{ x, y })
        .with(Renderable{
            glyph: rltk::to_cp437(')'),
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
            render_order: 2
        })
        .with(Name{ name : "Magic Missile Scroll".to_string() })
        .with(Item{})
        .with(Consumable{})
        .with(Ranged{ range: 6 })
        .with(InflictsDamage{ damage: 20 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn fireball_scroll(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position{ x, y })
        .with(Renderable{
            glyph: rltk::to_cp437(')'),
            fg: RGB::named(rltk::ORANGE),
            bg: RGB::named(rltk::BLACK),
            render_order: 2
        })
        .with(Name{ name : "Fireball Scroll".to_string() })
        .with(Item{})
        .with(Consumable{})
        .with(Ranged{ range: 6 })
        .with(InflictsDamage{ damage: 20 })
        .with(AreaOfEffect{ radius: 3 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn confusion_scroll(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position{ x, y })
        .with(Renderable{
            glyph: rltk::to_cp437(')'),
            fg: RGB::named(rltk::PINK),
            bg: RGB::named(rltk::BLACK),
            render_order: 2
        })
        .with(Name{ name : "Confusion Scroll".to_string() })
        .with(Item{})
        .with(Consumable{})
        .with(Ranged{ range: 6 })
        .with(Confusion{ turns: 4 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn dagger(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position{ x, y })
        .with(Renderable{
            glyph: rltk::to_cp437('/'),
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
            render_order: 2
        })
        .with(Name{ name : "Dagger".to_string() })
        .with(Item{})
        .with(Equippable{ slot: EquipmentSlot::Melee })
        .with(MeleePowerBonus{ power: 2 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn shield(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position{ x, y })
        .with(Renderable{
            glyph: rltk::to_cp437('('),
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
            render_order: 2
        })
        .with(Name{ name : "Shield".to_string() })
        .with(Item{})
        .with(Equippable{ slot: EquipmentSlot::Shield })
        .with(DefenseBonus{ defense: 1 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn longsword(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position{ x, y })
        .with(Renderable{
            glyph: rltk::to_cp437('/'),
            fg: RGB::named(rltk::YELLOW),
            bg: RGB::named(rltk::BLACK),
            render_order: 2
        })
        .with(Name{ name : "Longsword".to_string() })
        .with(Item{})
        .with(Equippable{ slot: EquipmentSlot::Melee })
        .with(MeleePowerBonus{ power: 4 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn tower_shield(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position{ x, y })
        .with(Renderable{
            glyph: rltk::to_cp437('('),
            fg: RGB::named(rltk::YELLOW),
            bg: RGB::named(rltk::BLACK),
            render_order: 2
        })
        .with(Name{ name : "Tower Shield".to_string() })
        .with(Item{})
        .with(Equippable{ slot: EquipmentSlot::Shield })
        .with(DefenseBonus{ defense: 3 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn rations(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position{ x, y })
        .with(Renderable{
            glyph: rltk::to_cp437('%'),
            fg: RGB::named(rltk::GREEN),
            bg: RGB::named(rltk::BLACK),
            render_order: 2
        })
        .with(Name{ name : "Rations".to_string() })
        .with(Item{})
        .with(ProvidesFood{})
        .with(Consumable{})
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn magic_mapping_scroll(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position{ x, y })
        .with(Renderable{
            glyph: rltk::to_cp437(')'),
            fg: RGB::named(rltk::CYAN3),
            bg: RGB::named(rltk::BLACK),
            render_order: 2
        })
        .with(Name{ name : "Scroll of Magic Mapping".to_string() })
        .with(Item{})
        .with(MagicMapper{})
        .with(Consumable{})
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn bear_trap(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position{ x, y })
        .with(Renderable{
            glyph: rltk::to_cp437('^'),
            fg: RGB::named(rltk::RED),
            bg: RGB::named(rltk::BLACK),
            render_order: 2
        })
        .with(Name{ name : "Bear Trap".to_string() })
        .with(Hidden{})
        .with(EntryTrigger{})
        .with(InflictsDamage{ damage: 6 })
        .with(SingleActivation{})
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}