More cleanup then starting to sort out how to make systems extensible easily.

tests/systems.cpp

@@ -34,3 +34,105 @@ TEST_CASE("figure out best rotation direction", "[systems-rotate]") {
     }
   }
 }
+
+using MovingFunc = std::function<void()>;
+using CombatFunc = std::function<void(bool)>;
+using RenderFunc = std::function<void()>;
+using UpdateFunc = std::function<void()>;
+using UseFunc = std::function<void()>;
+using PickupFunc = std::function<void()>;
+
+struct Engine {
+  std::vector<MovingFunc> $moving;
+  std::vector<CombatFunc> $combat;
+  std::vector<RenderFunc> $render;
+  std::vector<UpdateFunc> $update;
+  std::vector<UseFunc> $use;
+  std::vector<PickupFunc> $pickup;
+
+  void addMoving(MovingFunc action) {
+    $moving.emplace_back(action);
+  }
+
+  void addCombat(CombatFunc action) {
+    $combat.emplace_back(action);
+  }
+
+  void addRender(RenderFunc action) {
+    $render.emplace_back(action);
+  }
+
+  void addUpdate(UpdateFunc action) {
+    $update.emplace_back(action);
+  }
+
+  void addUse(UseFunc action) {
+    $use.emplace_back(action);
+  }
+
+  void addPickup(PickupFunc action) {
+    $pickup.emplace_back(action);
+  }
+
+  void runMoving() {
+    for(auto func : $moving) {
+      func();
+    }
+  }
+
+  void runCombat(bool attr) {
+    for(auto func : $combat) {
+      func(attr);
+    }
+  }
+
+  void runRender() {
+    for(auto func : $render) {
+      func();
+    }
+  }
+
+  void runUpdate() {
+    for(auto func : $update) {
+      func();
+    }
+  }
+
+  void runUse() {
+    for(auto func : $use) {
+      func();
+    }
+  }
+
+  void runPickup() {
+    for(auto func : $pickup) {
+      func();
+    }
+  }
+};
+
+void test_system_1() {
+  fmt::println("TEST 1");
+}
+
+void test_combat(bool what) {
+  fmt::println("TEST 2: {}", what);
+}
+
+TEST_CASE("new system running engine thing", "[systems-engine]") {
+  Engine systems;
+
+  systems.addMoving(test_system_1);
+  systems.addCombat(test_combat);
+  systems.addRender(test_system_1);
+  systems.addUpdate(test_system_1);
+  systems.addUse(test_system_1);
+  systems.addPickup(test_system_1);
+
+  systems.runCombat(false);
+  systems.runMoving();
+  systems.runRender();
+  systems.runUpdate();
+  systems.runUse();
+  systems.runPickup();
+}