[Qt-interest] Fwd: Fwd: Fwd: Fwd: qmake and staticlib issue

[Scott Aron Bloom]

Looking at your header...

 

You need to predeclare the following:

 

Light

Material

ViewableBase

GLRender

 

 

In your C++ file... you need to have defined

glDraw (GLRender)

 

Whatever MainView is

Light

And ViewableBase

 

But unless you provide a reproducalbe example of the code... I cant work
on it any further...

 

Ie,  an actual CPP and Header file...  What your showing is almost
worthless because I cant "try" to compile it and see the same error.

 

BTW.. in general, I find it VERY poor practice to rely on predeclare
inside C++ files.

 

Scott

 

 

From: qt-interest-bounces at trolltech.com
[mailto:qt-interest-bounces at trolltech.com] On Behalf Of ami guru
Sent: Tuesday, April 21, 2009 10:53 AM
To: qt-interest at trolltech.com
Subject: [Qt-interest] Fwd: Fwd: Fwd: Fwd: qmake and staticlib issue

 

The following snippet where the errors shows up from:

****************GLWidget.h***************



//do the forward 
//declaration instead
class CameraView;
class GLRender;
class PixelArray;

  int NumLights;          

  // Array of light pointers
  Light* LightArray[MAX_LIGHTS];

  int NumMaterials;       // Number of materials

  //Array of material pointers.
  Material* MatArray[MAX_MATERIALS];

  int NumObjects;         // Number of objects
  ViewableBase* ViewObj[MAX_OBJECTS];// Array of viewable object
pointers


  GLRender* glDraw;

**************************************'



***************GLWidget.cpp***********
#include "GLRender.h"


void GLWidget::RenderWithGL()
{
  
  /*
  if ( glDraw == 0 ) 
    {
      // Needs to be constructed *after* glut initialized.
      glDraw = new GLRender();        
    }

  // Set camera position
  glDraw->SetupCameraView( *MainView, 1.0, MAX_DIST );

  // Define all light sources
  int i;
  for ( i=0; i<NumLights; i++ ) 
    {
      glDraw->AddLight( *(LightArray[i]) );
    }

  glDraw->SetGlobalAmbientLight( GlobalAmbientR3 );
  glDraw->SetGlobalAmbientLight( 0.5, 0.5, 0.5 );
  
  // Render each ViewableObject
  for ( i=0; i< NumObjects; i++ ) 
    {
      glDraw->RenderViewable( *(ViewObj[i]) );
    }

  glDraw->FinishRendering();
  
  */
}



the commented part gives error
*****************************************


Regards
Sajjad

---------- Forwarded message ----------
From: Scott Aron Bloom <Scott.Bloom at sabgroup.com>
Date: Tue, Apr 21, 2009 at 6:52 PM
Subject: Re: [Qt-interest] Fwd: Fwd: Fwd: qmake and staticlib issue
To: qt-interest at trolltech.com



Without seeing the code.. its hard to give a definitive answer...

 

However.. the compiler doesn't pick on people... ie, its not saying..
hmm lets mess with Sajjad, and give this error that is in theory good
code...

 

Show the line of code the compiler is complaining about, and we might be
able to figure out what is going on...

 

Maybe you have a return type? Maybe it's a non reference...

 

Don't know...  But your theory is correct.. Mostly likely, your not
following it J

Scott

 

From: qt-interest-bounces at trolltech.com
[mailto:qt-interest-bounces at trolltech.com] On Behalf Of ami guru
Sent: Tuesday, April 21, 2009 6:50 AM


To: qt-interest at trolltech.com

Subject: [Qt-interest] Fwd: Fwd: Fwd: qmake and staticlib issue

 

If i forward declare a class then i only use the reference or pointer
for that class and we do not instantiate any object of that class.

That what  the theory says and i have used that accordingly.


In the GLWidget.h clas i have used the forward declared a class named
GLRender since i am using the pointer of its type.

In thr GLWidget.cpp file i am creating a object of GLRender with  the
new operator and there i have included the GLRender.h

It should not complain.

But it does.


Would like to know why?


Regards
Sajjad

---------- Forwarded message ----------
From: John McClurkin <jwm at nei.nih.gov>
Date: Tue, Apr 21, 2009 at 2:23 PM
Subject: Re: [Qt-interest] Fwd: Fwd: qmake and staticlib issue
To: qt-interest at trolltech.com

ami guru wrote:
> Hello Farid,
>
> Thanks a lot for the feedback.
>
> I have tried the absolute path instead of the relative one and it
works
> fine now.
>
>
> Now i have another error which i think will be off-topic to bring up
here.
>
>
> I am getting the error saying that
>
>
> invalid use of the incomplete type.
>
> When do we have these type of error?

This usually occurs when you forward declare a class but don't include
the header.


>
>
> Regards
> Sajjad
>
> On Mon, Apr 20, 2009 at 6:35 PM, Farid Derradji
> <farid.derradji at itwm.fraunhofer.de

> <mailto:farid.derradji at itwm.fraunhofer.de>> wrote:
>
>     Hello Sajjad,
>
>     Perhaps you should first check whether your compiled libraries
contain
>     all required symbols (methods):
>
>     objdump --demangle --syms libVrMath.a          > libVrMath.txt
>     objdump --demangle --syms libDataStructs.a     >
libDataStructs.txt
>     objdump --demangle --syms libOpenGLRender.a    >
libOpenGLRender.txt
>     objdump --demangle --syms libRaytraceMgr.a     >
libRaytraceMgr.txt
>     objdump --demangle --syms libGraphics.a        > libGraphics.txt
>
>     Hereby *objdump* is a pretty useful tool of the *binutils*
collection.
>     Note that you need the debug versions of your libraries if you
want to
>     use Option --syms.
>
>
>     Regards
>     Farid
>
>

_______________________________________________
Qt-interest mailing list
Qt-interest at trolltech.com
http://lists.trolltech.com/mailman/listinfo/qt-interest

 


_______________________________________________
Qt-interest mailing list
Qt-interest at trolltech.com
http://lists.trolltech.com/mailman/listinfo/qt-interest

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.qt-project.org/pipermail/qt-interest-old/attachments/20090421/3c946564/attachment.html