Add combat system

- Remove collisions system
- Add attack intent to random move system

src/systems/collisions.rs

@@ -1,17 +0,0 @@
-use crate::prelude::*;
-
-#[system]
-#[read_component(Point)]
-#[read_component(Player)]
-#[read_component(Enemy)]
-pub fn collisions(ecs: &mut SubWorld, commands: &mut CommandBuffer) {
-    let mut player_pos = Point::zero();
-    let mut players = <&Point>::query().filter(component::<Player>());
-    players.iter(ecs).for_each(|pos| player_pos = *pos);
-
-    let mut enemies = <(Entity, &Point)>::query().filter(component::<Enemy>());
-    enemies
-        .iter(ecs)
-        .filter(|(_, pos)| **pos == player_pos)
-        .for_each(|(entity, _)| commands.remove(*entity));
-}

src/systems/combat.rs

@@ -0,0 +1,29 @@
+use crate::prelude::*;
+
+#[system]
+#[read_component(WantsToAttack)]
+#[write_component(Health)]
+pub fn combat(ecs: &mut SubWorld, commands: &mut CommandBuffer) {
+    let mut attackers = <(Entity, &WantsToAttack)>::query();
+
+    let victims: Vec<(Entity, Entity)> = attackers
+        .iter(ecs)
+        .map(|(entity, attack)| (*entity, attack.victim))
+        .collect();
+
+    victims.iter().for_each(|(message, victim)| {
+        if let Ok(mut health) = ecs
+            .entry_mut(*victim)
+            .unwrap()
+            .get_component_mut::<Health>()
+        {
+            println!("Health before attack: {}", health.current);
+            health.current -= 1;
+            if health.current < 1 {
+                commands.remove(*victim);
+            }
+            println!("Health after attack: {}", health.current);
+        }
+        commands.remove(*message);
+    });
+}

src/systems/mod.rs

@@ -1,4 +1,4 @@
-mod collisions;
+mod combat;
 mod end_turn;
 mod entity_render;
 mod hud;
@@ -23,9 +23,9 @@ pub fn build_input_scheduler() -> Schedule {
 
 pub fn build_player_scheduler() -> Schedule {
     Schedule::builder()
-        .add_system(movement::movement_system())
+        .add_system(combat::combat_system())
         .flush()
-        .add_system(collisions::collisions_system())
+        .add_system(movement::movement_system())
         .flush()
         .add_system(map_render::map_render_system())
         .add_system(entity_render::entity_render_system())
@@ -39,6 +39,8 @@ pub fn build_monster_scheduler() -> Schedule {
     Schedule::builder()
         .add_system(random_move::random_move_system())
         .flush()
+        .add_system(combat::combat_system())
+        .flush()
         .add_system(movement::movement_system())
         .flush()
         .add_system(map_render::map_render_system())

src/systems/random_move.rs

@@ -3,9 +3,13 @@ use crate::prelude::*;
 #[system]
 #[read_component(Point)]
 #[read_component(MovingRandomly)]
-pub fn random_move(ecs: &mut SubWorld, commands: &mut CommandBuffer) {
+#[read_component(Health)]
+#[read_component(Player)]
+pub fn random_move(ecs: &SubWorld, commands: &mut CommandBuffer) {
     let mut movers = <(Entity, &Point, &MovingRandomly)>::query();
-    movers.iter_mut(ecs).for_each(|(entity, pos, _)| {
+    let mut positions = <(Entity, &Point, &Health)>::query();
+
+    movers.iter(ecs).for_each(|(entity, pos, _)| {
         let mut rng = RandomNumberGenerator::new();
         let destination = match rng.range(0, 4) {
             0 => Point::new(-1, 0),
@@ -14,12 +18,36 @@ pub fn random_move(ecs: &mut SubWorld, commands: &mut CommandBuffer) {
             _ => Point::new(0, 1),
         } + *pos;
 
-        commands.push((
-            (),
-            WantsToMove {
-                entity: *entity,
-                destination,
-            },
-        ));
+        let mut attacked = false;
+        positions
+            .iter(ecs)
+            .filter(|(_, target_pos, _)| **target_pos == destination)
+            .for_each(|(victim, _, _)| {
+                if ecs
+                    .entry_ref(*victim)
+                    .unwrap()
+                    .get_component::<Player>()
+                    .is_ok()
+                {
+                    commands.push((
+                        (),
+                        WantsToAttack {
+                            attacker: *entity,
+                            victim: *victim,
+                        },
+                    ));
+                    attacked = true;
+                }
+            });
+
+        if !attacked {
+            commands.push((
+                (),
+                WantsToMove {
+                    entity: *entity,
+                    destination,
+                },
+            ));
+        }
     });
 }