limit fps to 60 and disable imgui demo window

src/main.cpp

@@ -12,9 +12,19 @@
 #include <memory>
 #include <future>
 #include <iostream>
+#include <thread>
+#include <chrono>
 
 int main(int argc, char** argv) {
-	if (SDL_Init(SDL_INIT_EVERYTHING) < 0) {
+	// setup hints
+	if (SDL_SetHint(SDL_HINT_VIDEO_ALLOW_SCREENSAVER, "1") != SDL_TRUE) {
+		std::cerr << "Failed to set '" << SDL_HINT_VIDEO_ALLOW_SCREENSAVER << "' to 1\n";
+	}
+
+	auto last_time = std::chrono::steady_clock::now();
+
+	// actual setup
+	if (SDL_Init(SDL_INIT_VIDEO) < 0) {
 		std::cerr << "SDL_Init failed (" << SDL_GetError() << ")\n";
 		return 1;
 	}
@@ -54,8 +64,13 @@ int main(int argc, char** argv) {
 
 	std::unique_ptr<Screen> screen = std::make_unique<StartScreen>(renderer.get());
 
+
 	bool quit = false;
 	while (!quit) {
+		auto new_time = std::chrono::steady_clock::now();
+		//const float time_delta {std::chrono::duration<float, std::chrono::seconds::period>(new_time - last_time).count()};
+		last_time = new_time;
+
 		SDL_Event event;
 		while (SDL_PollEvent(&event)) {
 			if (event.type == SDL_EVENT_QUIT) {
@@ -73,6 +88,11 @@ int main(int argc, char** argv) {
 			break;
 		}
 
+		//float fps_target = 60.f;
+		//if (SDL_GetWindowFlags(window.get()) & (SDL_WINDOW_HIDDEN | SDL_WINDOW_MINIMIZED)) {
+			//fps_target = 30.f;
+		//}
+
 		ImGui_ImplSDLRenderer3_NewFrame();
 		ImGui_ImplSDL3_NewFrame();
 		ImGui::NewFrame();
@@ -91,6 +111,11 @@ int main(int argc, char** argv) {
 		// clearing after present is (should) more performant, but first frame is a mess
 		SDL_SetRenderDrawColor(renderer.get(), 0x10, 0x10, 0x10, SDL_ALPHA_OPAQUE);
 		SDL_RenderClear(renderer.get());
+
+		std::this_thread::sleep_for( // time left to get to 60fps
+			std::chrono::duration<float, std::chrono::seconds::period>(0.0166f) // 60fps frame duration
+			- std::chrono::duration<float, std::chrono::seconds::period>(std::chrono::steady_clock::now() - new_time) // time used for rendering
+		);
 	}
 
 	return 0;