Spawner, SpawnPoint and PlayerSpawn components, and base work on their systems

src/Game/Systems/SpawnerSystem.cpp

@@ -0,0 +1,47 @@
+#include "Systems/SpawnerSystem.h"
+
+SpawnerSystem::SpawnerSystem(EventBroker* eventBroker) : System(eventBroker)
+{
+    EVENT_SUBSCRIBE_MEMBER(m_OnSpawnerSpawn, &SpawnerSystem::OnSpawnerSpawn);
+}
+
+bool SpawnerSystem::OnSpawnerSpawn(Events::SpawnerSpawn& e)
+{
+    EntityWrapper& spawner = e.Spawner;
+
+    auto children = spawner.World->GetChildren(spawner.ID);
+    std::vector<EntityID> spawnPoints;
+    for (auto kv = children.first; kv != children.second; ++kv) {
+        const EntityID& child = kv->second;
+        if (spawner.World->HasComponent(child, "SpawnPoint")) {
+            spawnPoints.push_back(child);
+        }
+    }
+
+    EntityID spawnPoint = spawner.ID;
+    if (!spawnPoints.empty()) {
+        // Select a random spawn point
+        static std::random_device randomDevice;
+        static std::mt19937 randomGenerator(randomDevice());
+        std::uniform_int_distribution<> distribution(0, std::distance(spawnPoints.begin(), spawnPoints.end()) - 1);
+        auto randomSpawnPointIt = spawnPoints.begin();
+        std::advance(randomSpawnPointIt, distribution(randomGenerator));
+        spawnPoint = *randomSpawnPointIt;
+    }
+    spawnEntity(spawner, e.Parent.ID, Transform::AbsolutePosition(spawner.World, spawnPoint));
+
+    return true;
+}
+
+void SpawnerSystem::spawnEntity(EntityWrapper spawner, EntityID parent, glm::vec3 position)
+{
+    const std::string& entityFilePath = spawner["Spawner"]["EntityFile"];
+    auto entityFile = ResourceManager::Load<EntityFile>(entityFilePath);
+    if (entityFile == nullptr) {
+        return;
+    }
+
+    EntityFileParser parser(entityFile);
+    EntityWrapper spawnedEntity(spawner.World, parser.MergeEntities(spawner.World, parent));
+    spawnedEntity["Transform"]["Position"] = position;
+}