draw curved line from point to point - DOTNET

On 27 Jun., 23:40, Lakesider <i...@rudolfball.com> wrote:
> Dear NG,
>
> I want to draw a curved line like here:http://www.dusch-westermaier.de/img/wave.gif
> from a point A to a point B.
>
> Do you have any idea how to handle this in C#?
>
> Thank you very much,
>
> Rudi

I found this: http://www.codedblog.com/2007/09/17/...forms-textbox/
but it only draws a horizontal line ... not from A to B somewhere on
the screen.

Any ideas ... ?

Thank you

Rudi

You can draw a curve with multiple points but you must calculate the points.

I suggest that the easiest way would be to plot the points along a
horizontal line and then transfrom those points into position.

Take the hypotenuse of the right triangle defined by A and B, fill a set of
points to the rquired wavyness and then transform them into place.

Something like the code after my signature.

--
Bob Powell [MVP]
Visual C#, System.Drawing

Ramuseco Limited .NET consulting
http://www.ramuseco.com

Find great Windows Forms articles in Windows Forms Tips and Tricks
http://www.bobpowell.net/tipstricks.htm

Answer those GDI+ questions with the GDI+ FAQ
http://www.bobpowell.net/faqmain.htm

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// draw line from (10,10) to (150,75)

Point A = new Point(10, 10);

Point B = new Point(150, 75);

int sidea=B.X-A.X;

int sideb=B.Y-A.Y;

float hypot = (float)Math.Sqrt((sidea * sidea) + (sideb * sideb));

float angle = (float)Math.Atan2(sideb, sidea); // have to adjust this for
quadrant...

Point[] points = new Point[11];

//fill the point array

for (int c=0, n=10; c <= 10; n=-n, c++)

{

points[c] = new Point((int)(hypot/10*c),n);

}

//plot a and b to check the positions...

e.Graphics.DrawLine(Pens.Black, A.X, 0, A.X, 1000);

e.Graphics.DrawLine(Pens.Black, 0, A.Y, 1000, A.Y);

e.Graphics.DrawLine(Pens.Black, B.X, 0, B.X, 1000);

e.Graphics.DrawLine(Pens.Black, 0, B.Y, 1000, B.Y);

Matrix mx = new Matrix();

mx.Rotate((float)(angle/Math.PI*180));

mx.Translate(A.X, A.Y,MatrixOrder.Append);

//transform the points...

mx.TransformPoints(points);

// draw the curve

Pen p=new Pen(Color.Red,5);

e.Graphics.DrawCurve(p, points);

p.Dispose();

base.OnPaint(e);





"Lakesider" <info@rudolfball.com> wrote in message
news:f8b396b2-4027-4d0e-8cd2-8a346b3ba465@e53g2000hsa.googlegroups.com...
> Dear NG,
>
> I want to draw a curved line like here:
> http://www.dusch-westermaier.de/img/wave.gif
> from a point A to a point B.
>
> Do you have any idea how to handle this in C#?
>
> Thank you very much,
>
> Rudi

"Lakesider" <info@rudolfball.com> skrev i meddelandet
news:f8b396b2-4027-4d0e-8cd2-8a346b3ba465@e53g2000hsa.googlegroups.com...
> Dear NG,
>
> I want to draw a curved line like here:
> http://www.dusch-westermaier.de/img/wave.gif
> from a point A to a point B.
>
> Do you have any idea how to handle this in C#?
>
> Thank you very much,
>
> Rudi

Search for Bezier curves on Google, you will find numerous examples in code
of what Bob Powell wrote.
E.g. http://www.codeproject.com/KB/recipes/BezirCurves.aspx

Why not just calculate points using Math.Sin() function (or Cos if you
wish). Use this function: y = k * Sin(x). k is a constant and the lower the
k the more flat curve you get. Start with k = 1 and decrease it by 0.1 to
see results. Then create an array of points and calculate y for each x,
incrementing x by some dx untill you reach the right border. Then, draw a
polyline on a graphics using this point array. Try to use the largest number
possible for dx to decrease the amount of points while still having the
best-looking curve.

regards
Tomaz


"Lakesider" <info@rudolfball.com> wrote in message
news:f8b396b2-4027-4d0e-8cd2-8a346b3ba465@e53g2000hsa.googlegroups.com...
> Dear NG,
>
> I want to draw a curved line like here:
> http://www.dusch-westermaier.de/img/wave.gif
> from a point A to a point B.
>
> Do you have any idea how to handle this in C#?
>
> Thank you very much,
>
> Rudi