Basic combat system prototype works, but needs more GUI love to really work in the game.

systems.cpp

@@ -130,6 +130,34 @@ void System::death(GameLevel &level) {
   });
 }
 
+void System::combat(GameLevel &level) {
+  auto &collider = *level.collision;
+  auto &world = *level.world;
+  auto player = world.get_the<Player>();
+
+  const auto& player_position = world.get<Position>(player.entity);
+  auto& player_combat = world.get<Combat>(player.entity);
+
+  // this is guaranteed to not return the given position
+  auto [found, nearby] = collider.neighbors(player_position.location);
+
+  if(found) {
+    for(auto entity : nearby) {
+      if(world.has<Combat>(entity)) {
+        auto& enemy_combat = world.get<Combat>(entity);
+
+        Events::Combat result {
+          player_combat.attack(enemy_combat),
+          enemy_combat.attack(player_combat)
+        };
+
+        world.send<Events::GUI>(Events::GUI::COMBAT, entity, result);
+      }
+    }
+  }
+}
+
+
 void System::collision(GameLevel &level) {
   auto &collider = *level.collision;
   auto &world = *level.world;