Added pause menu, new F3 debug panel, fogCurve setting

src/engine.h

@@ -0,0 +1,67 @@
+#ifndef SRC_ENGINE_H_
+#define SRC_ENGINE_H_
+
+#include <string>
+#include <memory>
+#include <stdexcept>
+#include "typedefs.h"
+
+class Assets;
+class Level;
+
+namespace gui {
+	class GUI;
+}
+
+struct EngineSettings {
+    /* Window width (pixels) */
+	int displayWidth;
+	/* Window height (pixels) */
+	int displayHeight;
+	/* Anti-aliasing samples */
+	int displaySamples;
+	/* GLFW swap interval value, 0 - unlimited fps, 1 - vsync*/
+	int displaySwapInterval;
+	/* Window title */
+	const char* displayTitle;
+	/* Max milliseconds that engine uses for chunks loading only */
+	uint chunksLoadSpeed;
+	/* Radius of chunks loading zone (chunk is unit) */
+	uint chunksLoadDistance;
+	/* Buffer zone where chunks are not unloading (chunk is unit)*/
+	uint chunksPadding;
+	/* Fog opacity is calculated as `pow(depth*k, fogCurve)` where k depends on chunksLoadDistance.
+	   Use values in range [1.0 - 2.0] where 1.0 is linear, 2.0 is quadratic
+	*/
+	float fogCurve;
+};
+
+void load_settings(EngineSettings& settings, std::string filename);
+void save_settings(EngineSettings& settings, std::string filename);
+
+class initialize_error : public std::runtime_error {
+public:
+	initialize_error(const std::string& message) : std::runtime_error(message) {}
+};
+
+class Engine {
+	Assets* assets;
+	Level* level;
+	EngineSettings settings;
+
+	uint64_t frame = 0;
+	double lastTime = 0.0;
+	double delta = 0.0;
+	bool occlusion = true;
+
+	gui::GUI* gui;
+public:
+	Engine(const EngineSettings& settings);
+	~Engine();
+
+	void updateTimers();
+	void updateHotkeys();
+	void mainloop();
+};
+
+#endif // SRC_ENGINE_H_