[Openchrome-users] texture size limitations

[Bill McGonigle]

Hi, Folks,

I'm working on getting an app I've written working on openchrome,  
using a CN700-based board.  I'm relatively new to this, but I think I  
understand most of the distinctions between the various software  
parts and which controls which, but I'm still trying to figure out at  
least one issue, and a general strategy for figuring out others.

For instance, my app uses 1024x1024 textures.  From the 3DStatus page  
it says there is missing support for 'large textures', but I'm not  
sure what defines what a large texture is, or what causes the  
limitations.  A quick test shows that 1024x1024 textures won't render  
while a 512x512 texture does.  Perusing the mesa DRI via code I don't  
see an 'if ( texture.height > 512 || texture.width > 512)' type of  
limit, though I may have just totally missed it.  I'd like to figure  
out the smart approach, rather than hit each step by trial and error  
(though I see the CN700 should handle nPOT textures properly, so I  
can do it if need be).

So, in this instance I'd like to hear if anybody can point me to  
where the limit exists (hardware, openchrome, mesa, drm, etc.) and  
how I might best figure out, say, what the hardware limitations are.   
If it's "simply a matter of programming", maybe somebody could point  
me to the right place to get started on handling larger textures.   
Sorry for the green nature of the question, I'm new to this. :)

Also, does anybody maintain or know of a comparison between  
openchrome and via binary drivers?  e.g. how could I find out if the  
via driver supports larger textures already? (I didn't find feature  
docs on viaarena.com)  I'm in the 'open source is better' camp with  
both feet, but pragmatic approaches might help get my project some  
momentum, thereby giving me more resources for hacking on the open  
source code.

Thanks for reading the rambling,
-Bill

-----
Bill McGonigle, Owner           Work: 603.448.4440
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