feat: emitters random access & add ParticlesRenderer.gc()

src/graphics/render/ParticlesRenderer.hpp

@@ -5,6 +5,7 @@
 #include <unordered_map>
 
 #include "Emitter.hpp"
+#include "typedefs.hpp"
 
 class Texture;
 class Assets;
@@ -18,9 +19,11 @@ class ParticlesRenderer {
     const Assets& assets;
     const GraphicsSettings* settings;
     std::unordered_map<const Texture*, std::vector<Particle>> particles;
-    std::vector<std::unique_ptr<Emitter>> emitters;
     std::unique_ptr<MainBatch> batch;
 
+    std::unordered_map<u64id_t, std::unique_ptr<Emitter>> emitters;
+    u64id_t nextEmitter = 1;
+
     void renderParticles(const Camera& camera, float delta);
 public:
     ParticlesRenderer(
@@ -32,7 +35,17 @@ public:
 
     void render(const Camera& camera, float delta);
 
-    void add(std::unique_ptr<Emitter> emitter);
+    u64id_t add(std::unique_ptr<Emitter> emitter);
+
+    /// @brief Perform garbage collection (remove extra dead emitters).
+    /// @note Emitters are deleting without GC when there's no particles with same
+    /// texture left.
+    /// @note Currently unused
+    void gc();
+
+    /// @brief Get emitter by UID
+    /// @return Emitter or nullptr
+    Emitter* getEmitter(u64id_t id) const;
 
     static size_t visibleParticles;
     static size_t aliveEmitters;