DrawLine method provides higher quality than DrawLines method

Question

In my aplication I need to plot an equation. The plotted equation will be composed of many small linear lines. When I plot it using the DrawLine method inside a for I get higher quality than when using the DrawLines method.

Graphics canvas = pnlCanvas.CreateGraphics();
canvas.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

//High Quality
for (int i = 0; i < plot_points.Length - 1; i++)
{
    canvas.DrawLine(penKat, plot_points[i], plot_points[i + 1]);
}

//Low Quality
canvas.DrawLines(penKat, plot_points);

I need to plot it using the DrawLines method because of some issues. Is there a way to get high quality using that method?

Answer 1

Try:

 penKat.EndCap = System.Drawing.Drawing2D.LineCap.Round;
 penKat.StartCap = System.Drawing.Drawing2D.LineCap.Round;
 penKat.LineJoin = LineJoin.Round;

MiterLimit might help, if your lines are thicker than a few pixels..

Edit: For crisp joins you may want to experiment with other LineJoin values:

 penKat.LineJoin = LineJoin.MiterClipped;
 penKat.MiterLimit = 1.5f;

Or

 penKat.LineJoin = LineJoin.Miter;
 penKat.MiterLimit = 1.5f;

Do try out other MiteLimit values until you're happy! Or post an example image with the two versions..

For stroke widths of 2-4 pixels the difference between the LineJoins will not be very visible. This changes dramatically with growing stroke widths; so remember this property for those thicker lines!