csgl-users — General CsGL feedback list.

[Csgl-users] new CsGL release

[Lloyd D. <ll...@ga...>]

  a.. Version 1.4.1 released!=20
  b.. a new forum! again! this one should have a longer life and is =
quite nice ;-),
  please try the mailing list too...=20
  c.. the forum: Forum
  d.. Basically it's a maintenance release with lot of debugging.=20
  e.. The OpenGLContext creation has been rewrite / enhanced to be more =
easily customizable=20
  f.. The GL generator.exe generated incorrect code, it has been fixed. =
(and the OpenGL_Extension file regenerated)=20
  g.. A rarely see issue with incorrect calling convention on DllImport =
attribute fixed=20
  h.. OpenGLContext(s) could now share their display list with other =
context, customize your context to take advantage of this feature and =
save video memory !
  of course CsGL.OpenGL.ContextLocal class take advantage of this =
feature.=20
  i.. GDITextureFont work now very fine and simply. And you have a basic =
example <csgl>/examples/CS/gdifont.cs=20
  j.. mouse & keyboard event management work now very fine and there is =
an associated example <csgl>/examples/CS/event.cs=20
  k.. maintenance / compatiblity release of CsGLExample & GLViewer=20
  l.. I found this new C#-OpenGL related project http://www.headbits.com =
with some interesting stuff.=20

[Csgl-users] Multitexturing?

[Frank B. <fb...@bl...>]

Has anyone had any problems with multitexturing with the latest
(1.4) release of CsGL?  Regular textures work just fine, but when I try to
multitexture (glMultiTexture2fARB) I'm getting an "invalid operation
exception" (not particularly informative). I believe the coordinates
are correct, and the call is there...?  Help appreciated.

- Frank


----------------------------------------------
Frank Blecha                 http://blecha.org
Software Engineer
Agent Modeling Group
Information Operations       http://www.psl.nmsu.edu/io/
Physical Science Laboratory  http://www.psl.nmsu.edu
New Mexico State University  http://www.nmsu.edu

RE: [Csgl-users] rendering speed slower using GDIGLContext than if using ContolGLContext

[Ben H. <be...@ex...>]

Why not write into the overlay (OpenGL does have support for overlays)
using OpenGL?  That should be much faster than using GDI+.

Hope that helps...
-ben houston
http://www.exocortex.org/ben
"I am a man of fixed and unbending principles, the first of which is to
be flexible at all times." - Everett Dirksen

Re: [Csgl-users] rendering speed slower using GDIGLContext than if using ContolGLContext

[Lloyd D. <ll...@ga...>]

Well Aron,

I must confess your mail as a bit unclear to me. particularly the second
part.
In fact I understand what you want to do, but not clearly which problem you
have.

And I want some precision too.

> So far, I've been using a ControlGLContext but ControlGLContext.ToImage()
> throws an exception ("Invalid parameter used" from the Bitmap
constructor).
do you mean that
...
Bitmap img = new Bitmap(b[2], b[3],
System.Drawing.Imaging.PixelFormat.Format24bppRgb);
...
(code snippet of ToImage)
throw an exception ?

just a try, hack OpenGLContext and replace the last line of ToImage()
that is:
OpenGLException.Assert() by glGetError() ....


> I've been looking at GDIGLContext (which feels like the right way to go?)
> and I have been able to make it work, but the rendering takes about twice
> the time
I can't really help, this is the domain of the driver ...
Although I am thinking to make a HARDWARE_ACCELERATED flag visible, this
flags doesn't seem to exist on X-Windows (so far, according to what I read
in my doc) so I have some hesitation....

> compared to that when I use a ControlGLContext - event if the code
> in OnPaint() is never run.
what do you mean ?
even if OpenGL call doesn't draw on screen they take time.
In fact it seems that the GDI context is sotware OpenGL and all the computer
power lie on the CPU, which is more slower than the GPU for OpenGL calls....

> I would like to use CsGL 1.4.0 but using this version, the volumes
rendered
> using 2D and 3D textures have way too large distances between the textures
> (the distance between the textures - i.e. the number of textures - varies
> with the object's distance to the camera). Also, the problem above isn't
> solved by using 1.4.0. So I stick to CsGL 1.3.2. Any ideas or suggestions?
I clearly not understand what difference between 1.3.2 &  1.4.0 make you
stick to 1.3.2...
I would like to know to correct 1.4....

cheers,
Lloyd

[Csgl-users] rendering speed slower using GDIGLContext than if using ContolGLContext

[Aron E. <ar...@se...>]

Hi all,

what's the best way of combining OpenGL rendering with GDI overlays? I'm
working on a volume rendering application where the volume rendering
sometimes takes a lot of time. I would like to be able to change the overlay
graphics (currently some lines and short text strings) without having to
rerender the whole OpenGL scene, and preferably it should all be
doublebuffered. I.e. I would like to render to an offscreen bitmap and then,
in the OnPaint method do

  DrawImageUnscaled(renderedBitmap);
  DrawOverlays();

So far, I've been using a ControlGLContext but ControlGLContext.ToImage()
throws an exception ("Invalid parameter used" from the Bitmap constructor).

I've been looking at GDIGLContext (which feels like the right way to go?)
and I have been able to make it work, but the rendering takes about twice
the time compared to that when I use a ControlGLContext - event if the code
in OnPaint() is never run. In fact, if I only change this:

  ctxt = new ControlGLContext(this);

into this:

  bitmap = new Bitmap(width, height,
System.Drawing.Imaging.PixelFormat.Format32bppArgb);
  new GDIGLContext(Graphics.FromImage(renderedBitmap));

the following call, which in the first case makes the image appear on screen
and in the second case does not, takes twice the time:

  scene.Render();

scene is a volume rendering scene. Does this make sense to you guys!? To me,
it does not!

I would like to use CsGL 1.4.0 but using this version, the volumes rendered
using 2D and 3D textures have way too large distances between the textures
(the distance between the textures - i.e. the number of textures - varies
with the object's distance to the camera). Also, the problem above isn't
solved by using 1.4.0. So I stick to CsGL 1.3.2. Any ideas or suggestions?

Best regards,

Aron Ernvik

[Csgl-users] Dll help - solved

[Don-Duong Q. <dj...@ya...>]

I found a solution to my problem but I don't know why it works.  Anyway, for anyone that followed my previous posts, here's what I did.

I did the standard thing of declaring a couple macros to export/import dlls, for example:

#ifdef DLL_BUILD    #define GBEXPORT __declspec (dllexport)#else    #define GBEXPORT __declspec (dllimport)#endif

However after building the wrapper and running my C# test app, I'd get an exception thrown at me.  However linking with my static libs would fix it.  So I decided I would create static lib configurations.  So I changed my macros to:

#ifdef USING_DLL    #ifdef DLL_BUILD        #define GBEXPORT __declspec (dllexport)    #else        #define GBEXPORT __declspec (dllimport)    #endif#else    #define GBEXPORT#endif

When I was experimenting with dlls again, by accident I forgot to include USING_DLL in my wrapper projects. So for some weird reason when including dllimport in my wrapper project, I get weird problems with C#.  Oh well that's solved.

Don



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[Csgl-users] CsGL 1.4.0 released

[Lloyd D. <ll...@ga...>]

  a.. Version 1.4.0 released!=20
  b.. OpenGL 1.1, 1.2, 1.3, 1.4 & 50 additional extensions supported.=20
  c.. If you have the latest extension header for =
SomeNiftyNewExtensionFromCompanyX you could now automatically generate =
the CsGL extension file with glgenerator.exe in the =
<CsGL>extras\generator directory. It comes both precompiled and with =
source. Check the README file first if you want to hack it.=20
  d.. Mouse (including Cursor utility) and Keyboard class added to =
CsGL.Util=20
  e.. New related project, http://www21.brinkster.com/trapalas/ is a =
skin file reader and cloth simulator... very nice demo!=20
  f.. The NeHe tutorials have been taken out of the base distribution =
and will be found in a separate package, where a new developer (thanks =
Randy) is doing a really wonderful job and LOT of tutorials.=20
  g.. One last thing, I dropped Managed C++, this release is cleaner and =
is only comprised of C# and C. This will make it easier to port to other =
platforms... (provided you have System.Windows.Forms... of course)=20
  h.. The regular CsGL forum is broken and until it's fixed we're back =
to using the forum on SourceForge.=20
  i.. BUG There is a small pointer corruption somewhere, which I was not =
able to track until now and I know a very few case where glGetString() =
and OpenFileDialog (?!) doesn't work as intended.=20

[Csgl-users] Re: DLL Help...

[Lloyd D. <llo...@ya...>]

It looks like the value of _p is NULL. That's typical
of NullReferenceException ....

maybe you could put a cout << or printf in
~BinaryStream(), just to be sure...

sorry to not being more helpfull...

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[Csgl-users] Dll help - maybe a code snippet would help?

[Don-Duong Q. <dj...@ya...>]

Here's a code snippet from the managed C++ wrapper for gb::io::BinaryStream. 
#include "gbio/binarystream.h" // C++ class#using <MSCORLIB.DLL>using namespace System::Runtime::InteropServices;namespace gb { namespace cs { namespace io {     public __gc class BinaryStream     {     public:         BinaryStream ()        {            _p = new gb::io::BinaryStream ();        }        virtual ~BinaryStream ()        {            delete _p;            _p = 0;        }        int Open (System::String* s, int mode)        {            char *c_string = (char*)((void*)Marshal::StringToHGlobalAnsi (s));        // throws System.NullReferenceException            int ret = _p->Open (c_string, mode);             Marshal::FreeHGlobal ((System::IntPtr)((void*)c_string));            return ret;        }        void Close ()        {            _p->Close ();        }    // ...more code ....//    private:        gb::io::BinaryStream* _p;    };}// io}// cs}// gb

From "gbio/binarystream.h"        int gb::io::BinaryStream::Open (const std::string& filename, int mode)        {            mMode = std::ios_base::binary;            if (mode == READ)                mMode |= std::ios::in;            else if (mode == WRITE)                mMode |= std::ios::out;            else                return 0;            open (filename.c_str (), mMode);            return good ();        }
Thanks, Don


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[Csgl-users] DLL help

[Don-Duong Q. <dj...@ya...>]

This is indirectly related to CsGL.  I'll be using it to build an editor for my engine later.  I'm hoping someone can help me shed some light on a problem I'm having.  I've built my engine using C++ and exported it as dll libraries in VC++ 6.  I've gotten some C4251 warnings about not exporting standard libary, base classes, but they don't seem to be a problem.

I have a C++ class called gb::io::BinaryStream that I wrapped up in a managed C++ called gb::cs::io::BinaryStream.  gb::io::BinaryStream derives from std::basic_fstream< char > for file manipulation.  During my C# test app's construction, I have a variable of type gb::cs::io::BinaryStream that gets instantiated.

However when I call gb::cs::io::BinaryStream.Open function (which delegates to gb::io::BinaryStream.Open) I get:

An unhandled exception of type 'System.NullReferenceException' occurred in gbio_cs.dll

Additional information: Object reference not set to an instance of an object.

However, if I call gb::io::Close() no exception occurs.  I also can't step into the dll for debugging, but if I link with static versions of my libraries everything works fine. 

Has anyone experienced this?

Thanks,

Don



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[Csgl-users] (no subject)

[Lloyd D. <ll...@ga...>]

Hi Folks,

you could find a beta of coming 1.4 at http://stuff.galador.net
(browse up to the bottom of the page, you shoul see some csgl.1.4.0.xxx.zip
files)

It won't nearly change up to the release time except this:
a bit of change in CsGL.Util.Mouse
I will add Ridge & Dude NeHe tutorials (Ridge could you send me the last,
compatible version, please)
Some improvement still to do in the new CsGL.OpenGL.OpenGL_Extension class

this is a class of 10915 line of code. (I program fast guys, isn't it ?!)
generated by my new (still in beta) tool glgenerator (lok in
<csgl>/extra/generator)
which create C# extension from header file.
and it contains 1.2, 1.3, 1.4 call along with a lot of extension (thanks to
    Lev Povalahev
    le...@gm...
    http://www.uni-karlsruhe.de/~uli2/
)

[Csgl-users] Arrow Keys and keyEventHandler in OpenGLControl

[Michael G. <mg...@st...>]

Hi,

I'm a senior at Stetson University and I'm new to both C# and CsGL, but =
I am attempting to use CsGL and C# for my advanced graphics class this =
semester.  So for I'm been able to reporduce some of the Nehe lessons =
from the csgl src file I downloaded from srouceforge.net.  My only =
problem at this point is that for some unknown reason I can't get my =
arrow keys to work.  It's like the the keys don't even trigger the =
event.  Even when I rebuilt the nehe lessons (I think it was lesson nine =
that I did for this test) none of the arrow keys worked for those =
either.  As a result I made a test app that just tested the keys in c# =
and they worked fine but when you are testing the keys from an object =
that inherits from OpenGLControl, the arrow keys aren't detected.  Why =
is this so?  Is there a bug in CsGL that causes the OpenGLControl to not =
get KeyEvents from the arrow keys (I think the tab key doesn't work as =
well)?

In addition to that I tried to add a KeyEventHandler to see if that =
would work but it has the same problem.  but even so there is an =
additional problem in that the if the keyEvenHandler is added to the =
main form, no key events are registered (this is if the keyeventhandler =
methods are in the class that inherits from OpenGLControl).  Could =
someone please explain this or help me out on this one.  I've been =
searching through this code to figure out what the problem is but I'm =
with no success.

Is it something with csgl itself?

My code can be downloaded at =
http://www.stetson.edu/~mgilkes/FILES/3DBouncingBall.zip

Thanks,
Michael

RE: [Csgl-users] problem with using OpenGLControl in VS.NET

[Ben H. <be...@ex...>]

Ben's recommendation would be to stick with a C++ .NET backend.  I am
not sure why you want to switch?

-ben
http://www.exocortex.org/ben
"Those who wish to succeed must ask the right
preliminary questions." - Aristotle 
> -----Original Message-----
> From: Lloyd Dupont [mailto:ll...@ga...]
> Sent: Wednesday, August 28, 2002 4:49 AM
> To: Ben Houston; csg...@li...
> Subject: Re: [Csgl-users] problem with using OpenGLControl in VS.NET
> 
> I don't know but !...
> the latest release (not yest shipped but in beta here
> http://stuff.galador.net (at the bottom)) work well in VS.NET
(provided
> you
> also copy the the csgl-native.dll in your directory, as it is not an
> assembly) (yes, I finally get rid of managed C++, and I have good
reason
> for
> this)
> 
> this is a nearly finish beta release, but I am writting an automatic
> extension generator, and when it will be finished I will ship this new
> CsGL
> with heaps of OpenGL extension.
> 
> One very interesting class (not OpenGL related) is CsGL.Util.CFunction
> which
> permit you to call any C-Function pointer from C# without one line of
> C.....
> 
> ----- Original Message -----
> From: "Ben Houston" <be...@ex...>
> To: <csg...@li...>
> Sent: Wednesday, August 28, 2002 9:32 AM
> Subject: [Csgl-users] problem with using OpenGLControl in VS.NET
> 
> 
> > Hi,
> >
> > I can't seem to use the CsGL.OpenGL.OpenGLControl in the WYSIWYG
> > Designer of VisualStudio.NET.  It complains of an "Exception from
> > HRESULT: 0x80131019."  I can not figure out where this exception is
> > coming from.  Does anyone else know how to fix this error?
> >
> > Cheeers,
> > -ben
> > http://www.exocortex.org/ben
> > "Those who wish to succeed must ask the right
> > preliminary questions." - Aristotle
> >
> >
> > -------------------------------------------------------
> > This sf.net email is sponsored by: Jabber - The world's fastest
growing
> > real-time communications platform! Don't just IM. Build it in!
> > http://www.jabber.com/osdn/xim
> > _______________________________________________
> > Csgl-users mailing list
> > Csg...@li...
> > https://lists.sourceforge.net/lists/listinfo/csgl-users
> >

Re: [Csgl-users] problem with using OpenGLControl in VS.NET

[Lloyd D. <ll...@ga...>]

I don't know but !...
the latest release (not yest shipped but in beta here
http://stuff.galador.net (at the bottom)) work well in VS.NET (provided you
also copy the the csgl-native.dll in your directory, as it is not an
assembly) (yes, I finally get rid of managed C++, and I have good reason for
this)

this is a nearly finish beta release, but I am writting an automatic
extension generator, and when it will be finished I will ship this new CsGL
with heaps of OpenGL extension.

One very interesting class (not OpenGL related) is CsGL.Util.CFunction which
permit you to call any C-Function pointer from C# without one line of C.....

----- Original Message -----
From: "Ben Houston" <be...@ex...>
To: <csg...@li...>
Sent: Wednesday, August 28, 2002 9:32 AM
Subject: [Csgl-users] problem with using OpenGLControl in VS.NET


> Hi,
>
> I can't seem to use the CsGL.OpenGL.OpenGLControl in the WYSIWYG
> Designer of VisualStudio.NET.  It complains of an "Exception from
> HRESULT: 0x80131019."  I can not figure out where this exception is
> coming from.  Does anyone else know how to fix this error?
>
> Cheeers,
> -ben
> http://www.exocortex.org/ben
> "Those who wish to succeed must ask the right
> preliminary questions." - Aristotle
>
>
> -------------------------------------------------------
> This sf.net email is sponsored by: Jabber - The world's fastest growing
> real-time communications platform! Don't just IM. Build it in!
> http://www.jabber.com/osdn/xim
> _______________________________________________
> Csgl-users mailing list
> Csg...@li...
> https://lists.sourceforge.net/lists/listinfo/csgl-users
>

[Csgl-users] problem with using OpenGLControl in VS.NET

[Ben H. <be...@ex...>]

Hi,

I can't seem to use the CsGL.OpenGL.OpenGLControl in the WYSIWYG
Designer of VisualStudio.NET.  It complains of an "Exception from
HRESULT: 0x80131019."  I can not figure out where this exception is
coming from.  Does anyone else know how to fix this error?

Cheeers,
-ben
http://www.exocortex.org/ben
"Those who wish to succeed must ask the right
preliminary questions." - Aristotle 

RE: [Csgl-users] problem using the same context in more than one thread

[Lloyd D. <Ll...@5d...>]

..mmhh.. I see.
Well it's simple.
I don't exactly understand why you are not able to create a new context,
maybe it fail because it doesn't want to have its pixelformat setted again,
when there is already a current GLContext, I should investigate.

Anyway, your problemis a context can't be current in multiple thread.
I saw you grab() the context but never drop() (or IsCurrent=false) it. so
when you try to make it current in another thread it is an error, it
complains, that normal.

But now, you have rthe solution, call drop at the end of OnPaint() or
whatever place you judge appropriate...

-----Original Message-----
From: csg...@li...
[mailto:csg...@li...]On Behalf Of Aron Ernvik
Sent: Wednesday, 7 August 2002 8:07 
To: csg...@li...
Subject: [Csgl-users] problem using the same context in more than one
thread


CsGL users and developers,

I hope you can help me out with the following problem! I'm using CsGL for a
volume rendering application. I use an external volume rendering library
written in C++ for which I've written a managed wrapper. I've also created a
custom Control, VRTControl, which contains a ControlGLContext. In the
constructor I do

  public VRTControl() {
    ...
    ctxt = new ControlGLContext(this, CreateDisplayType());
    ctxt.Grab();

    // set up the context
    GL.glShadeModel(GL.GL_SMOOTH);
    GL.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    ...and so on
  }

Then there's a method called Render() in this VRTControl class:

  public void Render() {
    ctxt.Grab();
    GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
    if (scene != null) {
      scene.Render();      // perform the actual volume rendering
      glDraw();            // overlay graphics
      GL.glFinish();
      OpenGLException.Assert();
      ctxt.SwapBuffer();
    }
  }

scene.Render() performs the actual volume rendering and its output is sent
to the OpenGL buffers. All this works perfectly when the same thread calls
the constructor and VRTControl.Render(). It's been a pleasure working with
CsGL so far! Now for the problem: the call to scene.Render() typically takes
a lot of time, so I want to call MyControl.Render() using a separate thread.
But when I try this, I get the error message "Can't make the context
current" from the ctxt.Grab() call. When I try to recreate the context using
the rendering thread I get the error message "Invalid device context (DC)
handle" when calling ctxt.Dispose() on the old one. Ignoring this message
doesn't help - nothing ever shows on the context that is created by the
rendering thread.

What is the right way to have more than one thread using the same OpenGL
context? Is it at all possible? Or is it at least possible to create a new
ControlGLContext in a Control using another thread than the one that created
the control? (I haven't managed so far!)

Thanks a lot for any help! And keep up the really good work with CsGL!

Best regards,

Aron Ernvik, Sweden



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Re: [Csgl-users] problem using the same context in more than one thread

[Lloyd D. <ll...@ga...>]

Hi Aron,

Maybe it's your second message, I don't know it seems my mail server has
problem this morning and I am in a hurry now, so I would be short.


A thread cannot be local to 2 context.
when you call grab() on it, as it is already current in an another context
it cause an error.

you should drop() (or IsCurrent = false) it when you no longer need it, so
it's available in othre conext.

This make me think I should do 2 things:
1. comment this in the FAQ
2. make a function to query if a context is use in some context and may be a
wait method...


bye & good luck

PS: watch the mailing list maybe a csgl update in 1 month....

----- Original Message -----
From: "Aron Ernvik" <ar...@se...>
To: <csg...@li...>
Sent: Wednesday, August 07, 2002 8:06 PM
Subject: [Csgl-users] problem using the same context in more than one thread


> CsGL users and developers,
>
> I hope you can help me out with the following problem! I'm using CsGL for
a
> volume rendering application. I use an external volume rendering library
> written in C++ for which I've written a managed wrapper. I've also created
a
> custom Control, VRTControl, which contains a ControlGLContext. In the
> constructor I do
>
>   public VRTControl() {
>     ...
>     ctxt = new ControlGLContext(this, CreateDisplayType());
>     ctxt.Grab();
>
>     // set up the context
>     GL.glShadeModel(GL.GL_SMOOTH);
>     GL.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
>     ...and so on
>   }
>
> Then there's a method called Render() in this VRTControl class:
>
>   public void Render() {
>     ctxt.Grab();
>     GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
>     if (scene != null) {
>       scene.Render();      // perform the actual volume rendering
>       glDraw();            // overlay graphics
>       GL.glFinish();
>       OpenGLException.Assert();
>       ctxt.SwapBuffer();
>     }
>   }
>
> scene.Render() performs the actual volume rendering and its output is sent
> to the OpenGL buffers. All this works perfectly when the same thread calls
> the constructor and VRTControl.Render(). It's been a pleasure working with
> CsGL so far! Now for the problem: the call to scene.Render() typically
takes
> a lot of time, so I want to call MyControl.Render() using a separate
thread.
> But when I try this, I get the error message "Can't make the context
> current" from the ctxt.Grab() call. When I try to recreate the context
using
> the rendering thread I get the error message "Invalid device context (DC)
> handle" when calling ctxt.Dispose() on the old one. Ignoring this message
> doesn't help - nothing ever shows on the context that is created by the
> rendering thread.
>
> What is the right way to have more than one thread using the same OpenGL
> context? Is it at all possible? Or is it at least possible to create a new
> ControlGLContext in a Control using another thread than the one that
created
> the control? (I haven't managed so far!)
>
> Thanks a lot for any help! And keep up the really good work with CsGL!
>
> Best regards,
>
> Aron Ernvik, Sweden
>
>
>
> -------------------------------------------------------
> This sf.net email is sponsored by:ThinkGeek
> Welcome to geek heaven.
> http://thinkgeek.com/sf
> _______________________________________________
> Csgl-users mailing list
> Csg...@li...
> https://lists.sourceforge.net/lists/listinfo/csgl-users
>

[Csgl-users] problem using the same context in more than one thread

[Aron E. <ar...@se...>]

CsGL users and developers,

I hope you can help me out with the following problem! I'm using CsGL for a
volume rendering application. I use an external volume rendering library
written in C++ for which I've written a managed wrapper. I've also created a
custom Control, VRTControl, which contains a ControlGLContext. In the
constructor I do

  public VRTControl() {
    ...
    ctxt = new ControlGLContext(this, CreateDisplayType());
    ctxt.Grab();

    // set up the context
    GL.glShadeModel(GL.GL_SMOOTH);
    GL.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    ...and so on
  }

Then there's a method called Render() in this VRTControl class:

  public void Render() {
    ctxt.Grab();
    GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
    if (scene != null) {
      scene.Render();      // perform the actual volume rendering
      glDraw();            // overlay graphics
      GL.glFinish();
      OpenGLException.Assert();
      ctxt.SwapBuffer();
    }
  }

scene.Render() performs the actual volume rendering and its output is sent
to the OpenGL buffers. All this works perfectly when the same thread calls
the constructor and VRTControl.Render(). It's been a pleasure working with
CsGL so far! Now for the problem: the call to scene.Render() typically takes
a lot of time, so I want to call MyControl.Render() using a separate thread.
But when I try this, I get the error message "Can't make the context
current" from the ctxt.Grab() call. When I try to recreate the context using
the rendering thread I get the error message "Invalid device context (DC)
handle" when calling ctxt.Dispose() on the old one. Ignoring this message
doesn't help - nothing ever shows on the context that is created by the
rendering thread.

What is the right way to have more than one thread using the same OpenGL
context? Is it at all possible? Or is it at least possible to create a new
ControlGLContext in a Control using another thread than the one that created
the control? (I haven't managed so far!)

Thanks a lot for any help! And keep up the really good work with CsGL!

Best regards,

Aron Ernvik, Sweden

[Csgl-users] 1.3.2 update

[Lloyd D. <ll...@ga...>]

- version 1.3.2 released.
- some minor bug fixe
- a simple doc shipped
- extension N_Vertex added
- GLViewer (http://dev.galador.net/GLViewer) now read .3ds file and have a
nice light setting tool
- project Lilburn (http://www15.brinkster.com/lilburn/home.asp) started, a
3D engine library

RE: [Csgl-users] Compiling NeHe apps.

[jnsmith <jn...@ut...>]

Lloyd-

I finished documenting all of the pointer files (blegh), if you want 'em,
I'll send them express to you. I'm moving onto the other (more difficult
=) ) classes. Question: do you want me to convert the existing XML
documentation into the Java-like (CPPDOC) documentation or leave it? What
about the DllImport GL functions wrapped in the GL and GLU classes. These
are all well documented in the Red/Blue book ... is it necessary to repeat?

-j.

Re: [Csgl-users] How can I compile and execute simple C# program with GNU Make?

[Lloyd D. <ll...@ga...>]

mhh..
good question I will think to write a short tutorial on GNU make....
in the mean time you could either read this long tutorial
http://www.student.math.uwaterloo.ca/~cs-marks/resources/unix/make/tutorial/

or the complete makefile documentation
http://www.student.math.uwaterloo.ca/~cs-marks/resources/unix/make/gnumake/m
ake_toc.html

mingw (http://www.mingw.org) ship with a nice makefile complete reference in
one large html file.

about MS compiler...
you will need a release of VS to have the necessary lib file. (at least I
know that VC++ 5 will do), after that that you could use the C++ compiler
shipped with SDK.NET in
C:\Program Files\Microsoft Visual Studio .NET\Vc7\bin

mmhh.. this libs dependancy is a problem....
I could go back to gcc i the near future anyway as there is no managed C++
compiler on Linux and I plan to make the port....

[Csgl-users] How can I compile and execute simple C# program with GNU Make?

[VATSAL P. <ja...@ms...>]

I am using CsGL to use the opengl features. I could not find out how to 
compile and run my opengl c# program by using GNUmake and MS c compiler.
By the way, any one can help me about what is the MS C Compiler in .NET SDK 
and what is the file name of it?
Thanks.
Vatsal

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Re: [Csgl-users] CsGL example

[Lloyd D. <ll...@ga...>]

just a quick reply.
here:
ftp://ftp.sgi.com/opengl/opengl12.zip

you have a lot example (C file, but easily convertible)
tess.c is a tesselation example

----- Original Message ----- 
From: Claudio Rosadini 
To: csg...@li... 
Sent: Friday, June 22, 2001 3:32 PM
Subject: [Csgl-users] CsGL example


Where I find a example for tassellation (c# e CsGL library)?
Thank you. Claudio
cla...@pr...

[Csgl-users] CsGL example

[Claudio R. <cla...@pr...>]

Where I find a example for tassellation (c# e CsGL library)?
Thank you. Claudio
cla...@pr...

RE: [Csgl-users] Compiling NeHe apps.

[jnsmith <jn...@ut...>]

I was trying to compile the drawimage example and I'm getting an error on
the ctxt.Dispose() and gdi.Dispose(). I can comment these lines out and get
a compilable program that runs and produces a blank form, but clearly not
the model defined in model.cs. I've tried the 1.3 dlls and they also crash.
Any ideas?

-j.

-----Original Message-----
From: Lloyd Dupont [mailto:ll...@ga...]
Sent: Monday, June 17, 2002 9:08 AM
To: jnsmith
Subject: Re: [Csgl-users] Compiling NeHe apps.


ok.
don't bother too much
the VS.NET project will simply have no strong names....

I finally found that the working directory during compilation is something
like Release/obj and you .snk should be here or you AssemblyKeyFile should
be like "../../../csgl-base.snk", ugly !

I wil explain this in the FAQ for people who want to use VS.NET & strong
names (personally I don't understand why)

BTW I finally find out that the display bug that some people has was
completly my fault. I will soon ship a new bug fixes with some additional
OpenGL extension to make the new release more attractive.
is there some extension you would like to see ?

I mean 1 or 2, no more ....