DrawArc is Coming up Short

Question

I am having a small issue with using Graphics.DrawArc method. When used it's coming up short than what the actual size is. I am basing this control off another post found here

I am trying to make this into a UserControl with some properties and expand on it. The issue is when I set the percentage per say 50% it comes up short...

This is what the UserControl looks like at 50%... It's should be centered (blue) at the bottom of circle. I have tried adjusting everything I could, but I am at lost right now.

Here is my current code...

Color _ProgressCompletedColor = SystemColors.MenuHighlight;
    Color _ProgressNotCompleted = Color.LightGray;
    Int32 _ProgressThickness = 2;
    Single _ProgressCompleted = 25;

    public AttuneProgressBar()
    {
        InitializeComponent();
    }

    public Single PercentageCompleted
    {
        get
        {
            return this._ProgressCompleted;
        }
        set
        {
            this._ProgressCompleted = value;
            this.Invalidate();
        }
    }

    public Int32 ProgressBarThickness
    {
        get
        {
            return this._ProgressThickness;
        }
        set
        {
            this._ProgressThickness = value;
            this.Invalidate();
        }
    }

    public Color ProgressNotCompletedColor
    {
        get
        {
            return this._ProgressNotCompleted;
        }
        set
        {
            this._ProgressNotCompleted = value;
            this.Invalidate();
        }
    }

    public Color ProgressCompletedColor
    {
        get
        {
            return this._ProgressCompletedColor;
        }
        set
        {
            this._ProgressCompletedColor = value;
            this.Invalidate();
        }
    }

    protected override void OnPaint(PaintEventArgs e)
    {
        // Call the OnPaint method of the base class.
        base.OnPaint(e);

        DrawProgress(e.Graphics, new Rectangle(new Point(1,1), new Size(this.ClientSize.Width - 3, this.ClientSize.Height - 3)), PercentageCompleted);
    }

    private void DrawProgress(Graphics g, Rectangle rec, Single percentage)
    {  
        Single progressAngle = (360 / 100 * percentage);
        Single remainderAngle = 360 - progressAngle;

        try
        {
            using (Pen progressPen = new Pen(ProgressCompletedColor, ProgressBarThickness), remainderPen = new Pen(ProgressNotCompletedColor, ProgressBarThickness))
            {
                g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
                g.DrawArc(progressPen, rec, -90, progressAngle);
                g.DrawArc(remainderPen, rec, progressAngle - 90, remainderAngle);
            }
        }
        catch (Exception exc) { }
    }

}

Answer 1

You are calculating the angle with integers. When you do this:

angle = 360 / 100 * percentage;

it means

angle = 3 * percentage;

this of course leads to errors. There is a simple fix if you want to keep using ints:

angle = 360 * percentage / 100;

This way it doesn't get rounded down before multiplication. Or you can just use floats all the way:

angle = 360f / 100f * percentage;