Switch from specs to hecs

src/systems/monster_ai.rs

@@ -0,0 +1,92 @@
+use crate::{
+    components::{monster::*, *},
+    resources::Resources,
+    tile_data::TileType,
+};
+
+use bracket_lib::{prelude::*, random::RandomNumberGenerator};
+use hecs::*;
+
+pub fn run(world: &mut World, resources: &mut Resources) {
+    let player_position = world
+        .query::<(&Player, &Position)>()
+        .iter()
+        .map(|(_, (_, &pos))| pos)
+        .collect::<Vec<_>>()
+        .first()
+        .cloned();
+
+    if let Some(player_pos) = player_position {
+        let mut has_died = None;
+        for (entity, (monster, position, renderable)) in
+            &mut world.query::<(&mut Monster, &mut Position, &mut Renderable)>()
+        {
+            if resources.clock.has_ticked {
+                monster.ticks_until_move -= 1;
+                if monster.ticks_until_move <= 0 {
+                    // Change glyph
+                    let mut rng = RandomNumberGenerator::new();
+                    if let Some(glyph) =
+                        rng.random_slice_entry(&monster::glyphs_for_kind(monster.kind))
+                    {
+                        renderable.glyph = *glyph;
+                    }
+
+                    // Move monster
+                    let (mut delta_x, mut delta_y) = (0, 0);
+                    if player_pos.x < position.x {
+                        delta_x = -1;
+                    }
+                    if player_pos.x > position.x {
+                        delta_x = 1;
+                    }
+                    if player_pos.y < position.y {
+                        delta_y = -1;
+                    }
+                    if player_pos.y > position.y {
+                        delta_y = 1;
+                    }
+                    let destination = Point {
+                        x: position.x + delta_x,
+                        y: position.y + delta_y,
+                    };
+
+                    if let Some(e) = resources.map.get_tile_content_at(destination) {
+                        if let Ok(_player) = world.get::<Player>(e) {
+                            // TODO: Sound
+                            resources.map.clear_tile_content_at(Point::from(*position));
+                            resources.stats.take_gems(damage_for_kind(monster.kind));
+                            resources.sound_output.play_sound(sound_effect_for_kind(
+                                monster.kind,
+                                &resources.sound_effects,
+                            ));
+                            has_died = Some(entity);
+                        }
+                    } else {
+                        let tile = resources.map.get_tile_at_mut(destination);
+                        match tile {
+                            TileType::Wall => {}
+                            TileType::Block => {
+                                // TODO: Sound
+                                *tile = TileType::Floor;
+                                has_died = Some(entity);
+                            }
+                            _ => {
+                                resources.map.clear_tile_content_at(Point::from(*position));
+                                position.x = destination.x;
+                                position.y = destination.y;
+                                resources.map.set_tile_content_at(destination, entity);
+                            }
+                        }
+                    }
+
+                    monster.ticks_until_move = ticks_for_kind(monster.kind);
+                }
+            }
+        }
+
+        if let Some(e) = has_died {
+            let _ = world.despawn(e);
+        }
+    }
+}