smgr->drawAll() causes illegal operation

tkarkkainen · Post by **tkarkkainen** » Sun Nov 21, 2004 8:56 am

I have a class called CGame. In its header file I have this among other stuff under private

scene::ISceneManager *smgr;

And in the actual code I have stuff like

Code: Select all

device = createDevice ( video::EDT_OPENGL, core::dimension2d<s32>( 800, 600 ), 16, false, false, true, this );
printf ( "Device created [SUCCESS]\n" );
driver = device->getVideoDriver();
smgr = device->getSceneManager();

and later

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while ( device->run() )
{
   driver->beginScene( true, true, video::SColor ( 0, 100, 100, 100) );
   smgr->drawAll();
   driver->endScene();
}
device->drop();

According to the tutorials this should work. The program compiles without any errors or warnigns, but when I run the program and it reaches smgr->drawAll() Windows complains about an illegal operation. Is there anything that could cause this?

I use WinXP Pro SP1, Irrlicht 0.7 and Dev-C++ 4.9.8.0.

bal · Post by **bal** » Sun Nov 21, 2004 9:21 am

Wrong lib file, include files or the dll. Make sure those are correct. Also check if your smgr pointer doesn't get redefined somewhere before the draw loop.

tkarkkainen · Post by **tkarkkainen** » Sun Nov 21, 2004 2:56 pm

Thanks for the reply.

I checked include and lib directories. Include directory is irrlicht-0.7\include\ and lib irrlicht-0.7\lib\DevCpp which should be correct. Also, the dll is correct.smgr pointer doesn't get redefined.

Anything else I could check?

T101 · Post by **T101** » Sun Nov 21, 2004 6:03 pm

device = createDevice ( video::EDT_OPENGL, core::dimension2d<s32>( 800, 600 ), 16, false, false, true, this );

Is that in the event receiver?

tkarkkainen · Post by **tkarkkainen** » Mon Nov 29, 2004 5:42 pm

Sorry for the long silence.

T101: that line is in a class that is inherited from irr::IEventReceiver. Hopefully this bit of information helps.

I've really been pulling my hair out with this problem.

Guest · Post by **Guest** » Wed Dec 01, 2004 12:26 pm

According to the docu, drawAll must be called between BeginScene and EndScene - you've written that correctly.

But maybe BeginScene fails? You might want to check the return value of BeginScene: false if it fails.
Although I have no idea why it should fail.

Guest · Post by **Guest** » Wed Dec 01, 2004 12:32 pm

And looking a bit further:
when you call BeginScene with true,true, you're asking the driver to clear the backbuffer - I'm not sure you're guaranteed to get a backbuffer with OpenGL when you're running windowed. Maybe that's what's causing the error?

Guest · Post by **Guest** » Wed Dec 01, 2004 12:41 pm

Well, BeginScene doesn't fail. I added a row after it and it got executed (it printed "blah") and after that the illegal operation got thrown.

Spintz · Post by **Spintz** » Wed Dec 01, 2004 12:53 pm

It doesn't notify you of failing by ending the program. It fails by returning a false value. It's up to you to check that value and act on it. The fact that the print out worked after that call means nothing.

I'd bet you have a mismatch with your DLL and LIB files.

Guest · Post by **Guest** » Wed Dec 01, 2004 2:14 pm

but you also declare your device, driver, and scene manager under private. would this have any effect? what would happen if it were public?

tkarkkainen · Post by **tkarkkainen** » Wed Dec 01, 2004 4:43 pm

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       if ( ! driver->beginScene( true, true, video::SColor ( 0, 100, 100, 100) ) )
              printf ( "CATASTROPHIC FAILURE!" );
       smgr->drawAll();
       driver->endScene();

I tried this and it makes no difference. The program doesn't output catastrophic failure, but the problem still remains.

I'm using the Dev-C++ lib directories and the Dev-C++ DLL from Irrlicht 0.7. That shouldn't be a mismatch, right?

And finally, declaring device, driver and scene manager under public didn't help.

Spintz · Post by **Spintz** » Fri Dec 03, 2004 4:12 pm

To see if the device is actually being created, check it before continuing like so :

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device = 0;
device = createDevice ( video::EDT_OPENGL, core::dimension2d<s32>( 800, 600 ), 16, false, false, true, this ); 

if ( !device )
{
  printf ( "Failed to create device!\n" );
  return -1;
}

printf ( "Device created [SUCCESS]\n" ); 
driver = device->getVideoDriver(); 
smgr = device->getSceneManager();

Also, try changing your create device call to -

Code: Select all

device = createDevice ( video::EDT_OPENGL, core::dimension2d<s32>( 800, 600 ), 16, false, false, false, this );

This will turn off vsync, maybe this is your problem.

tkarkkainen · Post by **tkarkkainen** » Fri Dec 03, 2004 7:30 pm

I tried both. Didn't help but thanks for trying.

Guest · Post by **Guest** » Tue Dec 07, 2004 10:51 am

Did you at least try this:

device = createDevice ( video::EDT_OPENGL, core::dimension2d<s32>( 800, 600 ), 16, true, false, true, this );

That would create a full-screen session - which pretty mch guarantees that there's going to be a backbuffer to clear.

If it doesn't fail in that case, the problem is indeed in clearing the backbuffer - although I don't know why it would fail AFTER the clear.

tkarkkainen · Post by **tkarkkainen** » Tue Dec 07, 2004 2:03 pm

Yes, I indeed did try that.