[Openchrome-users] XAA SolidFillRect problem with negative x value

[Thomas Hellström]

Benno Schulenberg wrote:
> Mark Huijgen wrote:
>   
>> Then I looked at the code in viaInitXAA(ScreenPtr pScreen) and
>> disabled this part (commented out)
>> xaaptr->SetClippingRectangle = viaSetClippingRectangle;
>> xaaptr->DisableClipping = viaDisableClipping;
>> xaaptr->ClippingFlags
>>     
>
> Then it would be interesting to know with what values 
> viaSetClippingRectangle is called when the glitch occurs.
>
> If negative, then I'd think that it's at least also an application 
> error, because, when fullscreen, how can it have a negative x?
>
>   
>> Anyway I dont know what the via chip does and what it does not
>> support in hardware, but it seems negative x's for solid fill
>> isnt one of the things it supports.
>>     
>
> Nor does, probably, the intel chip.  When in the intel driver you 
> artificially create a negative x value in SubsequentSolidFillRect, 
> does it glitch too?  Or does it get properly clipped?
>
> Benno
>
>   
It may also be a sign bug in the driver.

I'm not sure whether the hardware can cope with negative x values but if 
it can,
they definitely need to be masked, since they only occupy 16 bits:

x &= 0xFFFF;

and this is not done currently.

It would be good to keep the hardware clipping if the hardware can with it.
/Thomas


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