Fixed TimeStep 1 Core nearly 100 %

[CodingDolphin]

Dear Lady's and Gentlemen,

i have a Problem, i try to get a Fixed Timestep Loop running. I got it so far that it now has the same Framerate on 60 or 99999(and everything between).

If i use VSYNC the Programm need a whole Core to run this simple Program. --> http://snag.gy/kADOW.jpg

BUT

If i use SetMaxFrameRate(60) i use just 1 - 3 % of my CPU --> http://snag.gy/byQlA.jpg

Can somebody please tell me where is the Problem of my Code?

http://pastebin.com/5XtkgJDC

(click to show/hide)

using System;
using SFML.Window;
using SFML.Graphics;
using SFML.Audio;
using System.Diagnostics;
 
namespace SFML_Project_64_Bit
{
    class Program
    {
        static void Main(string[] args)
        {
            MySFMLProgram app = new MySFMLProgram();
            app.StartSFMLProgram();
        }
    }
    class MySFMLProgram
    {
 
        //Window and Cam
 
        public  RenderWindow _window;
        public  View camera;
 
 
        //Asset
 
        protected Texture playTexture;
        protected Sprite playSprite;
 
        //Time Vars
 
        const double frame = 60;
        const double timeStep = 1 / frame;
        double timeBank;
        TimeSpan dT;
       
 
        public void StartSFMLProgram()
        {
            LoadContent();
 
            //Render Window
 
            _window = new RenderWindow(new VideoMode(1280, 760), "SFML window");
            _window.SetVisible(true);
            //_window.SetFramerateLimit(60);
            _window.SetVerticalSyncEnabled(true);
            _window.Closed += new EventHandler(OnClosed);
 
            //Camera
 
            camera = new View(new Vector2f(0, 0), new Vector2f(1280, 760));
 
 
            //DeltaTime
 
            dT = new TimeSpan();
            Stopwatch timer = new Stopwatch();
            timer.Start();
           
            while (_window.IsOpen())
            {
                timeBank += dT.TotalSeconds;
                Console.WriteLine(timeBank);
 
                if (timeBank >= timeStep)
                {
                    camera.Rotation += 1f;
                    _window.SetView(camera);
                    timeBank -= timeStep;
                }
 
                _window.DispatchEvents();
                this.Draw();
 
                dT = timer.Elapsed;
                timer.Restart();
            }
        }
 
        public void Draw()
        {
            _window.Clear(Color.Red);
            _window.Draw(playSprite);
            _window.Display();
        }
 
        void OnClosed(object sender, EventArgs e)
        {
            _window.Close();
        }
 
        public void LoadContent()
        {
            playTexture = new Texture("GraphicAsset/playButton.png");
            playSprite = new Sprite(playTexture);
            playTexture.Smooth = true;
        }
    }
}

Greetings

Dolphin

[eXpl0it3r]

Oh this is C# something code. Was just confused about your CamelCase bits.

As for VSync, check your driver settings. Some drivers allow you to force VSync off, so the setting with SFML, will have no affect.

[CodingDolphin]

Thanks for the quick reply,

i did change now my NVIDA Setting's to forced on and let the program decide. With VSYNC on my Program still use the Full Core.

Greetings

WhySoSad

[eXpl0it3r]

Then it might be a cheap/bad implementation of VSync in your driver. To get zero latency they sometimes using a spinlock or something like that, which will make out the CPU, but they then can at least guarantee proper VSync.

With "Fixed TimeStep" in your title, are you trying to fix your frame time with VSync, so you get a fixed timestep for your logic, or were you actually talking about fixed timestep?
If it was the first, then stop now. You should not try to fix your frame time and then use it for your calculations. Always assume that the frametime will be jumping, as such you might want to look at the link above.
If you actually meant what is mentioned in the linked article, then there's no reason in requiring VSync at all cost. Your logic will already be independent of whatever your frame time does.

[CodingDolphin]

Then it might be a cheap/bad implementation of VSync in your driver. To get zero latency they sometimes using a spinlock or something like that, which will make out the CPU, but they then can at least guarantee proper VSync.

With "Fixed TimeStep" in your title, are you trying to fix your frame time with VSync, so you get a fixed timestep for your logic, or were you actually talking about fixed timestep?
If it was the first, then stop now. You should not try to fix your frame time and then use it for your calculations. Always assume that the frametime will be jumping, as such you might want to look at the link above.
If you actually meant what is mentioned in the linked article, then there's no reason in requiring VSync at all cost. Your logic will already be independent of whatever your frame time does.

Very very strange, i have a up to date NVIDA Driver, and yes i try the second one may i have a mistake in my Code? But it seems too work.

Unfornatly i dont have any Content in my Project so i can't test if this will cause later Stutter with more Content and AI Calculation's and Stuff.

Greetings

Dolphin

[eXpl0it3r]

It's not about having an up to date driver, this is intended behavior by NVidia. You could kind of think of it as if you had implemented a busy-waiting loop to make sure that you render only when the refreshing for the monitor is happening, all the other time is spent just looping around doing nothing.
But if you now were to implement some logic for your game, the busy-waiting loop will do iterations. That way your CPU core will always be maxed, but you still got frame time left for your logic.

If it's really the case, then you shouldn't get stuttering later on, unless you implemented it wrong (I didn't check any of your code bits).