How can I draw Quadratic Curve through 3 points by using C# System.Drawing namespace?
+3
A:
Do you want to draw a quadratic curve that goes through three given points, or do you want to draw a quadratic Bézier curve that uses three given points?
If what you want is a Bézier curve, try this:
private void AddBeziersExample(PaintEventArgs e)
{
// Adds a Bezier curve.
Point[] myArray =
{
new Point(100, 50),
new Point(120, 150),
new Point(140, 100)
};
// Create the path and add the curves.
GraphicsPath myPath = new GraphicsPath();
myPath.AddBeziers(myArray);
// Draw the path to the screen.
Pen myPen = new Pen(Color.Black, 2);
e.Graphics.DrawPath(myPen, myPath);
}
Which I just shamelessly lifted from the MSDN documentation for GraphicsPath.AddBeziers()
.
Edit: If what you really want is to fit a quadratic curve, then you need to do a curve fitting or polynomial interpolation on your points. Perhaps this answer from Ask Dr. Math will help.
Daniel Pryden
2009-09-19 03:52:21