finished combat chapter 8

src/components.rs

@@ -21,6 +21,12 @@ pub struct WantsToMove {
     pub destination: Point,
 }
 
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct WantsToAttack {
+    pub attacker: Entity,
+    pub victim: Entity,
+}
+
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub struct Health {
     pub current: i32,

src/systems/combat.rs

@@ -0,0 +1,27 @@
+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 +1,5 @@
 use crate::prelude::*;
+mod combat;
 mod end_turn;
 mod entity_render;
 mod hud;
@@ -20,6 +21,8 @@ pub fn input_build_scheduler() -> Schedule {
 }
 pub fn player_build_scheduler() -> Schedule {
     Schedule::builder()
+        .add_system(combat::combat_system())
+        .flush()
         .add_system(movement::movement_system())
         .flush()
         .add_system(map_render::map_render_system())
@@ -32,6 +35,8 @@ pub fn monster_build_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/player_input.rs

@@ -3,6 +3,8 @@ use crate::prelude::*;
 #[system]
 #[read_component(Point)]
 #[read_component(Player)]
+#[read_component(Enemy)]
+#[write_component(Health)]
 pub fn player_input(
     ecs: &mut SubWorld,
     commands: &mut CommandBuffer,
@@ -18,16 +20,52 @@ pub fn player_input(
             VirtualKeyCode::Down => Point::new(0, 1),
             _ => Point::new(0, 0),
         };
-        players.iter(ecs).for_each(|(entity, pos)| {
-            let destination = *pos + delta;
-            commands.push((
-                (),
-                WantsToMove {
-                    entity: *entity,
-                    destination,
-                },
-            ));
-        });
+        let (player_entity, destination) = players
+            .iter(ecs)
+            .find_map(|(entity, pos)| Some((*entity, *pos + delta)))
+            .unwrap();
+        let mut enemies = <(Entity, &Point)>::query().filter(component::<Enemy>());
+
+        let mut did_something = false;
+        if delta.x != 0 || delta.y != 0 {
+            let mut hit_something = false;
+            enemies
+                .iter(ecs)
+                .filter(|(_, pos)| **pos == destination)
+                .for_each(|(entity, _)| {
+                    hit_something = true;
+                    did_something = true;
+
+                    commands.push((
+                        (),
+                        WantsToAttack {
+                            attacker: player_entity,
+                            victim: *entity,
+                        },
+                    ));
+                });
+
+            if !hit_something {
+                did_something = true;
+                commands.push((
+                    (),
+                    WantsToMove {
+                        entity: player_entity,
+                        destination,
+                    },
+                ));
+            }
+        }
+
+        if !did_something {
+            if let Ok(mut health) = ecs
+                .entry_mut(player_entity)
+                .unwrap()
+                .get_component_mut::<Health>()
+            {
+                health.current = i32::min(health.max, health.current + 1);
+            }
+        }
         *turn_state = TurnState::PlayerTurn;
     }
 }

src/systems/random_move.rs

@@ -3,9 +3,12 @@ pub use crate::prelude::*;
 #[system]
 #[read_component(Point)]
 #[read_component(MovingRandomly)]
+#[read_component(Health)]
+#[read_component(Player)]
 pub fn random_move(ecs: &mut 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),
@@ -13,12 +16,36 @@ pub fn random_move(ecs: &mut SubWorld, commands: &mut CommandBuffer) {
             2 => Point::new(0, -1),
             _ => 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,
+                },
+            ));
+        }
     });
 }