all of the changes

include/FluidSim/Desktop/EngineRenderer3D.hpp

@@ -0,0 +1,19 @@
+#pragma once
+#include "FluidSim/Scenario.hpp"
+#include "FluidSim/Desktop/OrbitCamera.hpp"
+#include <SFML/Graphics.hpp>
+#include <memory>
+namespace fluidsim::port::desktop {
+// Visualization consumes snapshots only; it never accesses mutable solver state.
+class EngineRenderer3D {
+public:
+    EngineRenderer3D();
+    ~EngineRenderer3D();
+    EngineRenderer3D(const EngineRenderer3D&)=delete;
+    EngineRenderer3D& operator=(const EngineRenderer3D&)=delete;
+    void draw(sf::RenderWindow&,const ScenarioSnapshot&,sf::FloatRect,const OrbitCamera&);
+private:
+    struct Impl;
+    std::unique_ptr<Impl> impl_;
+};
+}