Thanks Andreas.

I will try these.

Orion

Andreas Raab andreas.raab-at-gmx.de |squeak devlists| wrote:
> Hi Orion -
> 
> Well, debugging these issues goes roughly like follows:
> * You go to squeak.hpl.hp.com and choose to "browse the VM repository"
> * Here you navigate to
>     trunk/platforms/Cross/plugins/B3DAcceleratorPlugin
> * Look at sqOpenGLRenderer.c to find line 409 (you probably have to 
> download the file and use a reasonable text editor to find it)
> * Line 409 is in glSetTransform:
> 407:    DPRINTF(5, (fp, "### Installing new transformations\n"));
> 408:    glMatrixMode(GL_PROJECTION);
> 409:    ERROR_CHECK;
> 
> So it looks like glMatrixMode() is failing, right? Wrong! The 
> ERROR_CHECK macro uses glGetError() and glGetError() will keep the error 
> around until it has been reported. So the only thing we know is that 
> sometime *before* the method was called the error has occured. Time to 
> look at the Squeak side.
> 
> The easiest (and likely best) thing to do is to throw in an occasional 
> glGetError() check in your own code and print it to the transcript. Here 
> is a safe way way of doing this:
> 
> printError: ogl
>     err := ogl glGetError().
>     err = 0 ifFalse:[
>         WorldState addDeferredUIMessage:[
>             Transcript cr; show: 'OpenGL error: ', err hex.
>         ].
>     ].
> 
> This will print out any errors and from here it's basically divide and 
> conquer - just use binary search (or random guesses ;-) to narrow down 
> where the error occurs.
> 
> The exercise left for the reader: Write a OpenGLErrorTrap class which 
> automatically checks for the first occurance of a glGetError() after 
> invoking any of the OpenGL methods. Hint: Make it a ProtoObject subclass 
> and learn more about proxies ;-)
> 
> Cheers,
>   - Andreas
> 
> orion elenzil wrote:
> 
>> any tips how i'd track down a bug like this ?
>> i'm getting one per frame, it looks like.
>>
>> from squeak3d.log:
>>
>> ERROR (file sqOpenGLRenderer.c, line 409): a GL function failed -- 
>> GL_INVALID_ENUM
>>
>>
>> tia,
>> orion
>>
>>
>>
>>
>> ---
>> You are currently subscribed to croquet as: andreas.raab at gmx.de
>> To unsubscribe send a blank email to leave-croquet-872834H at lists.wisc.edu
>>
>>
> 
> ---
> You are currently subscribed to croquet as: sv04er502 at sneakemail.com
> To unsubscribe send a blank email to leave-croquet-872834H at lists.wisc.edu