How do i display/show FPS on screen?

Question

I have this code sample i need to find how to show/display the frames per second on the screen. Tried to use the class but its not working good im not sure how to use it.

protected override void Initialize()
{
    base.Initialize();

    fpsm = new FpsMonitor();
    fpsm.Update();
    fpsm.Draw(spriteBatch, fonts, new Vector2(5,5), Color.Red);

}

protected override void Update(GameTime gameTime)
{
    // Allows the game to exit
    if (GamePad.GetState(PlayerIndex.One).Buttons.Back ==
        ButtonState.Pressed)
        this.Exit();

    modelRotation += (float)gameTime.ElapsedGameTime.TotalMilliseconds *
        MathHelper.ToRadians(0.1f);

    base.Update(gameTime);
}

protected override void Draw(GameTime gameTime)
{
    graphics.GraphicsDevice.Clear(Color.CornflowerBlue);

    // Copy any parent transforms.
    Matrix[] transforms = new Matrix[myModel.Bones.Count];
    myModel.CopyAbsoluteBoneTransformsTo(transforms);

    // Draw the model. A model can have multiple meshes, so loop.
    foreach (ModelMesh mesh in myModel.Meshes)
    {
        // This is where the mesh orientation is set, as well 
        // as our camera and projection.
        foreach (BasicEffect effect in mesh.Effects)
        {
            effect.EnableDefaultLighting();
            effect.World = transforms[mesh.ParentBone.Index] *
                Matrix.CreateRotationY(modelRotation)
                * Matrix.CreateTranslation(modelPosition);
            effect.View = Matrix.CreateLookAt(cameraPosition,
                Vector3.Zero, Vector3.Up);
            effect.Projection = Matrix.CreatePerspectiveFieldOfView(
                MathHelper.ToRadians(45.0f), aspectRatio,
                1.0f, 10000.0f);
        }
        // Draw the mesh, using the effects set above.
        mesh.Draw();
    }
    base.Draw(gameTime);
}

And the FPS class:

public class FpsMonitor
{
    public float Value { get; private set; }
    public TimeSpan Sample { get; set; }
    private Stopwatch sw;
    private int Frames;
    public FpsMonitor()
    {
        this.Sample = TimeSpan.FromSeconds(1);
        this.Value = 0;
        this.Frames = 0;
        this.sw = Stopwatch.StartNew();
    }
    public void Update()
    {
        if (sw.Elapsed > Sample)
        {
            this.Value = (float)(Frames / sw.Elapsed.TotalSeconds);
            this.sw.Reset();
            this.sw.Start();
            this.Frames = 0;
        }
    }
    public void Draw(SpriteBatch SpriteBatch, SpriteFont Font, Vector2 Location, Color Color)
    {
        this.Frames++;
        SpriteBatch.DrawString(Font, "FPS: " + this.Value.ToString(), Location, Color);
    }
}

I tried in the Game1.cs to use it in the constructor:

fpsm = new FpsMonitor();
fpsm.Update();
fpsm.Draw(spriteBatch, fonts, new Vector2(5,5), Color.Red);

But thats not how to use it. How do i use it and where in my code ?

Answer 1

From what I see

fpsm = new FpsMonitor(); // in constructor
fpsm.Update();// in update I think first line

spriteBatch.Begin();  // in draw Last lines probably even after base.Draw(gameTime);
fpsm.Draw(spriteBatch, fonts, new Vector2(5,5), Color.Red);
spriteBatch.End();

That should work like a charm

[Edit for spritefont explanation]

You will need to create a SpriteFont. To do that right click Content chose add new and create spritefont. It is an XML file that will be converted when you compile. you can change the font and height I suggest Arial and 10.... you can always change that.

Next you need to load it. I usually do it like this.

in the class

private Spritefont Arial10;

in the LoadContent

Arial10 = Content.Load<Spritefont>("Arial10");

Now you can do this

spriteBatch.Begin();  // in draw Last lines probably even after base.Draw(gameTime);
fpsm.Draw(spriteBatch, Arial10 , new Vector2(5,5), Color.Red);
spriteBatch.End();

Answer 2

You can't draw the FPS in the Initialize method. You need to draw in the Draw method, and update in the Update method. Your FPS will never draw if it doesnt draw it on the Draw method. Initialize is only called once ever, and your GraphicsDevice is cleared every single frame.

Within Game1.cs from the Initialize method, remove these lines:

fpsm.Update();
fpsm.Draw(spriteBatch, fonts, new Vector2(5,5), Color.Red);

Add fpsm.Update(); to the Update() method, and add this to your Draw method within Game1.cs (after GraphicsDevice.Clear(Color.CornflowerBlue);):

spriteBatch.Begin();
fpsm.Draw(spriteBatch, fonts, new Vector2(5,5), Color.Red);
spriteBatch.End();

I am pretty sure this is what you need to do.

Don't forget to load the font in the LoadContent() method by doing:

fonts = Content.Load<SpriteFont>("MySpriteFont");

Also the spritefont needs to be a compiled file from your contents project! Just right-click on the content project, select Add > New Item and choose a SpriteFont file.