From f002ea2ecaf77b8283f1b71648db3a6572134640 Mon Sep 17 00:00:00 2001
From: ohyzha <oleksii.hyzha.ext@madvoxel.com>
Date: Fri, 23 Aug 2024 17:05:06 +0300
Subject: [PATCH] implement fps limiter

---
 openVulkanoCpp/Base/EngineConfiguration.hpp   |  2 +-
 .../Controller/FreeCamCameraController.cpp    |  2 +-
 openVulkanoCpp/Host/GraphicsAppManager.cpp    | 29 ++++++++++++++++++-
 openVulkanoCpp/Host/GraphicsAppManager.hpp    | 11 ++++++-
 4 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/openVulkanoCpp/Base/EngineConfiguration.hpp b/openVulkanoCpp/Base/EngineConfiguration.hpp
index 27f299f..347fec7 100644
--- a/openVulkanoCpp/Base/EngineConfiguration.hpp
+++ b/openVulkanoCpp/Base/EngineConfiguration.hpp
@@ -48,7 +48,7 @@ namespace OpenVulkano
 		bool m_preferFramebufferFormatSRGB = true;
 		bool m_lazyRendering = false;
 		bool m_vSync = false;
-		int32_t m_fpsCap = -1; // -1 = no fps cap. 0 = fps cap if vsync, no cap otherwise. > 0 = set fps cap
+		int32_t m_fpsCap = 500; // -1 = no fps cap. 0 = fps cap if vsync, no cap otherwise. > 0 = set fps cap
 		#ifdef __APPLE__
 				uint32_t m_preferredImageCount = 3;
 		#else
diff --git a/openVulkanoCpp/Controller/FreeCamCameraController.cpp b/openVulkanoCpp/Controller/FreeCamCameraController.cpp
index 71da9cc..8f94d3e 100644
--- a/openVulkanoCpp/Controller/FreeCamCameraController.cpp
+++ b/openVulkanoCpp/Controller/FreeCamCameraController.cpp
@@ -32,7 +32,7 @@ namespace OpenVulkano
 			vec = Math::Utils::normalize(vec);
 		}
 
-		float timeScale = 5 * CURRENT_FRAME.frameTime; //TODO
+		float timeScale = 3 * CURRENT_FRAME.frameTime; //TODO
 		vec = vec * timeScale * 3.0f; // scale vector
 		if (input->GetButton(m_actionBoost))
 		{
diff --git a/openVulkanoCpp/Host/GraphicsAppManager.cpp b/openVulkanoCpp/Host/GraphicsAppManager.cpp
index f9cd1bb..6d29b66 100644
--- a/openVulkanoCpp/Host/GraphicsAppManager.cpp
+++ b/openVulkanoCpp/Host/GraphicsAppManager.cpp
@@ -19,6 +19,8 @@
 
 namespace OpenVulkano
 {
+	using clock = std::chrono::steady_clock;
+
 	GraphicsAppManager::GraphicsAppManager(OpenVulkano::IGraphicsApp* app, RenderAPI::RenderApi renderApi)
 		: app(app), renderApi(renderApi)
 	{
@@ -37,6 +39,8 @@ namespace OpenVulkano
 		renderer = std::unique_ptr<IRenderer>(PlatformProducer::CreateRenderManager(renderApi));
 		app->SetGraphicsAppManager(this);
 		window->SetWindowHandler(this);
+		inputManager = Input::InputManager::GetInstance();
+		engineConfig = EngineConfiguration::GetEngineConfiguration();
 	}
 
 	GraphicsAppManager::GraphicsAppManager(IGraphicsApp* app, IWindow* window, RenderAPI::RenderApi renderApi)
@@ -57,6 +61,24 @@ namespace OpenVulkano
 		renderer = std::unique_ptr<IRenderer>(PlatformProducer::CreateRenderManager(renderApi));
 		app->SetGraphicsAppManager(this);
 		window->SetWindowHandler(this);
+		inputManager = OpenVulkano::Input::InputManager::GetInstance();
+		engineConfig = OpenVulkano::EngineConfiguration::GetEngineConfiguration();
+	}
+
+	void GraphicsAppManager::OnCappedFPS(const auto& frameStartTime) 
+	{
+		int32_t fpsCap = engineConfig->GetFpsCap();
+		fpsCapRemainder += 1000 % fpsCap;
+		auto frameTime = std::chrono::milliseconds(1000 / fpsCap);
+		if (fpsCapRemainder >= fpsCap)
+		{
+			frameTime += std::chrono::milliseconds(1);
+			fpsCapRemainder -= fpsCap;
+		}
+		while (clock::now() < frameStartTime + frameTime)
+		{
+			std::this_thread::yield();
+		}
 	}
 
 	GraphicsAppManager::~GraphicsAppManager() noexcept
@@ -139,9 +161,14 @@ namespace OpenVulkano
 		}
 		else
 		{
-			Input::InputManager::GetInstance()->Tick();
+			auto start = clock::now();
+			inputManager->Tick();
 			app->Tick();
 			if (CURRENT_FRAME.needsRedraw) renderer->Tick();
+			if (engineConfig->GetFpsCap() > 0 && !engineConfig->GetVSync())
+			{
+				OnCappedFPS(start);
+			}
 			frameTimer.Tick();
 			UpdateFps();
 			CURRENT_FRAME.frameId = frameCount;
diff --git a/openVulkanoCpp/Host/GraphicsAppManager.hpp b/openVulkanoCpp/Host/GraphicsAppManager.hpp
index 5d4b627..d264e1b 100644
--- a/openVulkanoCpp/Host/GraphicsAppManager.hpp
+++ b/openVulkanoCpp/Host/GraphicsAppManager.hpp
@@ -18,6 +18,11 @@
 namespace OpenVulkano
 {
 	class IPlatform;
+	namespace Input
+	{
+		class InputManager;
+	}
+	class EngineConfiguration;
 
 	/**
 	 * \brief A simple GraphicsAppManager. It can only handle one window.
@@ -32,10 +37,14 @@ namespace OpenVulkano
 		RenderAPI::RenderApi renderApi;
 		bool paused = false, running = false;
 		float fpsTimer = 0, avgFps = 0, avgFrameTime = 0;
-		uint64_t frameCount = 0, lastFrameCount = 0;
+		uint64_t frameCount = 0, lastFrameCount = 0, fpsCapRemainder = 0;
 		Timer frameTimer;
 		std::string windowTitleFormat;
+		Input::InputManager* inputManager;
+		EngineConfiguration* engineConfig;
 
+	private:
+		void OnCappedFPS(const auto& frameStartTime);
 	public:
 		explicit GraphicsAppManager(IGraphicsApp* app, RenderAPI::RenderApi renderApi = RenderAPI::Vulkan);