[Openchrome-users] 3D engine drawing.

Thomas Hellström unichrome
Thu Dec 8 14:54:05 PST 2005


Sergey wrote:

>Hello Thomas.
>Can you give me reference on implementation function drawing triangle
>directly VIA Unichrome videocard?
>Please.
>I can't find it.
>Best Regards Sergey.
>
>  
>
Unfortunately it's not that simple. You first have to upload a state to 
the 3D engine setting a number of registers, then you send floating 
point vertex coordiantes representing the triangle corners to the 
hardware and finally you tell the hardware you're done, and ask it to 
draw. This involves a bunch of operations, and the data given to the 
card has to be given using a binary command stream that are either 
submitted using AGP DMA or using the PCI memory mapped transmission space.

A minimalist implementation that can draw a (optionally textured) 
triangle / quadrilateral will be present in the openchrome driver in the 
not too distant future, if I can find some time to do it.

May I ask what type of application you plan to write?

/Thomas


>>----- Original Message -----
>>From: "Thomas Hellstr" <unichrome at shipmail.org>
>>To: "S!" <k9876543 at list.ru>
>>Cc: <openchrome-users at openchrome.org>
>>Sent: Wednesday, December 07, 2005 5:25 PM
>>Subject: Re: [Openchrome-users] VIA Unichrome graphics functions
>>    
>>
>programming
>  
>
>>    
>>
>>>Hi!
>>>
>>>S! wrote:
>>>
>>>      
>>>
>>>>Hello.
>>>>Can you help me?
>>>>I going to write own VIA Unichrome graphics functions for 3D
>>>>acceleration.
>>>>I need the function which discribes the bringing out-process of
>>>>        
>>>>
>triangle
>  
>
>>>>on the screen with given data
>>>>How do it?
>>>>Can you give me any documentations,  manuals or source code about it.
>>>>Best Regards Sergey.
>>>>
>>>>        
>>>>
>>>1) Manuals, You need to request manuals under Non-Disclosure Agreement
>>>from VIA.
>>>2) Source code: Go to http://dri.sourcefourge.net, take a look at Mesa
>>>      
>>>
>and
>  
>
>>>its src/mesa/drivers/dri/unichrome subdirectory. Also some help may be
>>>find from the drm kernel sources linux-core/via_verifier.c. I'm planning
>>>to include a very limited 3D functionality in the OpenChrome driver to
>>>      
>>>
>be
>  
>
>>>able to use the two texture units for compositing acceleration, but I'm
>>>not sure when that is going to happen.
>>>3) If you want to build your own DRI client to write to the hardware
>>>directly, take a look in the openchrome libxvmc subdirectory. The XvMC
>>>clients do just that.
>>>
>>>
>>>      
>>>
>>>>------------------------------------------------------------------------
>>>>
>>>>_______________________________________________
>>>>openchrome-users mailing list
>>>>openchrome-users at openchrome.org
>>>>http://wiki.openchrome.org/mailman/listinfo/openchrome-users
>>>>
>>>>        
>>>>
>>>      
>>>
>>    
>>
>
>  
>




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