rust-rl/src/monster_ai_system.rs

69 lines
2.8 KiB
Rust

use super::{bystander_ai_system, EntityMoved, Map, Monster, Position, TakingTurn, Viewshed, WantsToMelee};
use rltk::Point;
use specs::prelude::*;
pub struct MonsterAI {}
impl<'a> System<'a> for MonsterAI {
#[allow(clippy::type_complexity)]
type SystemData = (
WriteExpect<'a, Map>,
WriteExpect<'a, rltk::RandomNumberGenerator>,
ReadExpect<'a, Point>,
ReadExpect<'a, Entity>,
Entities<'a>,
WriteStorage<'a, Viewshed>,
ReadStorage<'a, Monster>,
WriteStorage<'a, Position>,
WriteStorage<'a, WantsToMelee>,
WriteStorage<'a, EntityMoved>,
ReadStorage<'a, TakingTurn>,
);
fn run(&mut self, data: Self::SystemData) {
let (
mut map,
mut rng,
player_pos,
player_entity,
entities,
mut viewshed,
monster,
mut position,
mut wants_to_melee,
mut entity_moved,
turns,
) = data;
for (entity, mut viewshed, _monster, mut pos, _turn) in
(&entities, &mut viewshed, &monster, &mut position, &turns).join()
{
let distance = rltk::DistanceAlg::Pythagoras.distance2d(Point::new(pos.x, pos.y), *player_pos);
if distance < 1.5 {
wants_to_melee
.insert(entity, WantsToMelee { target: *player_entity })
.expect("Unable to insert attack.");
} else if viewshed.visible_tiles.contains(&*player_pos) {
// If the player is visible, but the path is obstructed, this will currently search
// the entire map (i.e. Will do a huge ASTAR to find an alternate route), and the
// mob will follow that path until it leaves vision, then lose sight of the player
// and stop.
let path = rltk::a_star_search(map.xy_idx(pos.x, pos.y), map.xy_idx(player_pos.x, player_pos.y), &*map);
if path.success && path.steps.len() > 1 {
let mut idx = map.xy_idx(pos.x, pos.y);
map.blocked[idx] = false;
pos.x = (path.steps[1] as i32) % map.width;
pos.y = (path.steps[1] as i32) / map.width;
idx = map.xy_idx(pos.x, pos.y);
map.blocked[idx] = true;
viewshed.dirty = true;
entity_moved.insert(entity, EntityMoved {}).expect("Unable to insert marker");
}
} else {
if bystander_ai_system::try_move_randomly(&mut pos, &mut rng, &mut map, &mut viewshed) {
entity_moved.insert(entity, EntityMoved {}).expect("Unable to insert marker");
}
}
}
}
}