Talyrond

Heres how I solved this problem in my app. In the constructor of my Direct3D control, I hook up the� DeviceResizing� event AddHandler Me.Device.DeviceResizing, AddressOf CancelResize And the CancelResize sub: Protected Sub CancelResize(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) 'If the window is to small or minimized, cancel the resize event to prevent crashing. If Me.Width = 0 OrElse Me.Height = 0 Then e.Cancel = True End If End Sub

I have a bootstrapper setup so MDX is now a prerequisite, see the link: http://www.gotdotnet.com/workspaces/workspace.aspx?id=7e8e8cbd-b447-4a9d-a984-9379d1a0c190 From memory I had a bit of work to get it going, but it works well and will install DX9.0c and MDX if needed.

You may want to take a look at this thread on another forum: http://www.vbcity.com/forums/topic.asp?tid=95435 Download the last Rubberband project I did. As marble_eater suggested unless you are drawing more than 3-4 thousand lines I would redraw all the lines every time. Always avoid using CreateGraphics, you will never get flicker free graphics.

I think Bob Powell offers consultancy: http://www.bobpowell.net/

Not sure if this is what you need: If Me.DesignMode Then MessageBox.Show(" I am in design mode!") End If

Depending on what you are doing, I think doubles are the way to go, all computational geometry is performed with doubles, all be it in C or C++. But that does not matter. I guess you are hitting floating point arithmetic errors, I spend a lot of time dealing with this issue! It�s something that has to be dealt with I�m afraid.

Hi all, just dipping my toe into DirectX from using OpenGL, does DirectX have any native support for Nurbs surfaces, or any form of spline curves? I cant seem to find anything, but confirmation would be much appreciated Talyrond

Looks like OpenGL would do the job: http://www.csharpopenglframework.com/

Back to OPenGL, if it's your thing, then you may interested in this: http://www.devdept.com/code/oglf/index.php I have ported to VB as well, it's real easy to use the OPenGL.cs file as a class library in vb. Enjoy Talyrond

Not sure if this is what you are looking for: http://blogs.msdn.com/mharsh/

If performance is an issue I would use a profiler, you will be amassed where bottle necks occur Talyrond

Just a point of interest, performance is a real issue with my CAD system, I have spent many an our deliberating over what perform better. The day I tried out a performance profile (I use ANTS profiler) it was a revelation, I kid you not, with in two hours I saw a 15 fold increase in speed in a key area. You can hone in on bottle necks, you will be surprised what sort of thing cause performance issues. If you are serious about performance, you need a profiler.

gmp, I dont know what you requirements are for your app, but I would guess that GDI+ is more than adequate. I would recommend checking out this link and the whole site: http://www.bobpowell.net/manipulate_graphics.htm Have a look and then decide what approach you want to take

Thanks for taking the time to look at my problem Iceplug. Yes that sounds like a viable solution, good idea! I know you have a lot of experience in this field, so would you say that I have used the matrix correctly and that the effect I am seeing is just a limitation of GDI+, that�s my real worry, my package will making extensive use of them so I don�t want to be coding with sub standard techniques, that I need to re do later! Cheers Talyrond

Hi all I am programming the zoom on by CAD system. The problem I have is when I what to zoom in on very small primitives. I have attached a small project to demonstrate, the program draws a horizontal line and scales it to fit with a 10 pixel border. If you change the m_startX and/or the m_endX to any value you want you will see that the line scales as expected When the line is 0.00059 in length or smaller it will not be drawn, for example if you had: m_startX = 0 m_endX = 0.0005 So my question whether I am using the Matrix transformation correctly? Or have I hit some sort of limit. I know that I am talking about very small numbers, but I will be working with these sorts of sizes. I have a couple of ideas to work around this but I am interested in what is really going on, so I have a better understanding. Any help would be appreciated, I am struggling with this one. Cheers! Small Units.zip