1 files changed, 120 insertions, 0 deletions
diff --git a/engine-ecs/examples/event_loop.rs b/engine-ecs/examples/event_loop.rs
new file mode 100644
index 0000000..62d0876
--- /dev/null
+++ b/engine-ecs/examples/event_loop.rs
@@ -0,0 +1,120 @@
+use engine_ecs::actions::Actions;
+use engine_ecs::pair::{ChildOf, Pair};
+use engine_ecs::phase::{Phase, UPDATE as UPDATE_PHASE};
+use engine_ecs::{declare_entity, Component, Query, World};
+
+#[derive(Component)]
+struct Wool
+{
+    remaining: u32,
+}
+
+#[derive(Component)]
+struct Health
+{
+    health: u32,
+}
+
+#[derive(Component)]
+struct Name
+{
+    name: &'static str,
+}
+
+fn sheer(query: Query<(&mut Wool, &Name)>)
+{
+    for (mut wool, name) in &query {
+        if wool.remaining == 0 {
+            println!("{} Has no wool left", name.name);
+
+            continue;
+        }
+
+        // Sheer the whool
+        wool.remaining -= 5;
+
+        println!("Sheered 5 wool from {}", name.name);
+    }
+}
+
+fn feed(query: Query<(&mut Health, &Name)>)
+{
+    for (mut health, name) in &query {
+        health.health += 1;
+
+        println!("Feeded {} which gained 1 health", name.name);
+    }
+}
+
+fn age(query: Query<(&mut Health, &Name)>, mut actions: Actions)
+{
+    for (mut health, name) in &query {
+        if health.health <= 2 {
+            health.health = 0;
+
+            println!("{} passed away", name.name);
+
+            actions.stop();
+
+            continue;
+        }
+
+        health.health -= 2;
+
+        println!("{} aged and lost 2 health", name.name);
+    }
+}
+
+declare_entity!(
+    SHEER_PHASE,
+    (
+        Phase,
+        Pair::builder()
+            .relation::<ChildOf>()
+            .target_id(*UPDATE_PHASE)
+            .build()
+    )
+);
+
+declare_entity!(
+    FEED_PHASE,
+    (
+        Phase,
+        Pair::builder()
+            .relation::<ChildOf>()
+            .target_id(*SHEER_PHASE)
+            .build()
+    )
+);
+
+declare_entity!(
+    AGE_PHASE,
+    (
+        Phase,
+        Pair::builder()
+            .relation::<ChildOf>()
+            .target_id(*FEED_PHASE)
+            .build()
+    )
+);
+
+fn main()
+{
+    let mut world = World::new();
+
+    world.create_declared_entity(&SHEER_PHASE);
+    world.create_declared_entity(&FEED_PHASE);
+    world.create_declared_entity(&AGE_PHASE);
+
+    world.register_system(*SHEER_PHASE, sheer);
+    world.register_system(*FEED_PHASE, feed);
+    world.register_system(*AGE_PHASE, age);
+
+    world.create_entity((
+        Wool { remaining: 30 },
+        Health { health: 3 },
+        Name { name: "Bessy" },
+    ));
+
+    world.start_loop();
+}