Keith Whitwell schrieb:
> On Fri, 2009-09-25 at 02:02 -0700, Christoph Bumiller wrote:
>> Module: Mesa
>> Branch: master
>> Commit: 513cadf5afad18516f7299ade246f59d520753d0
>> URL:    
>> http://cgit.freedesktop.org/mesa/mesa/commit/?id=513cadf5afad18516f7299ade246f59d520753d0
>>
>> Author: Christoph Bumiller <e0425...@student.tuwien.ac.at>
>> Date:   Thu Sep 24 17:37:08 2009 +0200
>>
>> nv50: actually enable view volume clipping
>>
>> Until now, only primitives wholly outside the view volume
>> were not drawn.
>> This was only visibile when using a viewport smaller than
>> the window size, naturally.
>>
>> ---
>>
>>  src/gallium/drivers/nv50/nv50_state_validate.c |   11 ++++++++++-
>>  1 files changed, 10 insertions(+), 1 deletions(-)
>>
>> diff --git a/src/gallium/drivers/nv50/nv50_state_validate.c 
>> b/src/gallium/drivers/nv50/nv50_state_validate.c
>> index 5a3559e..4ed7697 100644
>> --- a/src/gallium/drivers/nv50/nv50_state_validate.c
>> +++ b/src/gallium/drivers/nv50/nv50_state_validate.c
>> @@ -312,7 +312,7 @@ scissor_uptodate:
>>                      goto viewport_uptodate;
>>              nv50->state.viewport_bypass = bypass;
>>  
>> -            so = so_new(12, 0);
>> +            so = so_new(14, 0);
>>              if (!bypass) {
>>                      so_method(so, tesla, NV50TCL_VIEWPORT_TRANSLATE(0), 3);
>>                      so_data  (so, fui(nv50->viewport.translate[0]));
>> @@ -325,12 +325,21 @@ scissor_uptodate:
>>  
>>                      so_method(so, tesla, NV50TCL_VIEWPORT_TRANSFORM_EN, 1);
>>                      so_data  (so, 1);
>> +                    /* 0x0000 = remove whole primitive only (xyz)
>> +                     * 0x1018 = remove whole primitive only (xy), clamp z
>> +                     * 0x1080 = clip primitive (xyz)
>> +                     * 0x1098 = clip primitive (xy), clamp z
>> +                     */
>> +                    so_method(so, tesla, NV50TCL_VIEW_VOLUME_CLIP_CTRL, 1);
>> +                    so_data  (so, 0x1080);
>>                      /* no idea what 0f90 does */
>>                      so_method(so, tesla, 0x0f90, 1);
>>                      so_data  (so, 0);
>>              } else {
>>                      so_method(so, tesla, NV50TCL_VIEWPORT_TRANSFORM_EN, 1);
>>                      so_data  (so, 0);
>> +                    so_method(so, tesla, NV50TCL_VIEW_VOLUME_CLIP_CTRL, 1);
>> +                    so_data  (so, 0x0000);
>>                      so_method(so, tesla, 0x0f90, 1);
>>                      so_data  (so, 1);
>>              }
>>
> 
> Chris,
> 
> Do you notice any performance difference after doing this?  I suspect
> that the fastpath for a lot of hardware is to actually avoid
> geometry-based clipping and do it with the rasterizer.  If this forces
> geometry clipping on when not required, it may bottleneck the hardware
> in vertex processing.
> 
> I'm only guessing, but something to keep in mind or investigate one day.
> 
> Keith
> 
I did measure a slight performance decrease, yes, but I just wanted
correct behaviour for now, and there's no pipe state for the viewport
boundaries (yet) (although I could infer them from scale & xlate).

The binary driver also doesn't do this, but I kind of wanted to show
that it could be done.

I guess I'll deactivate vertex clipping again when I swap the scissor
and viewport regs (as we probably have them reversed, current viewport
affects clear and scissor doesn't), which will happen when I have a
reason to, which is when I'm able to tell the state tracker it doesn't
have to fallback in any of the buffer clear cases :-)

Thanks for the hint,
Christoph

------------------------------------------------------------------------------
Come build with us! The BlackBerry&reg; Developer Conference in SF, CA
is the only developer event you need to attend this year. Jumpstart your
developing skills, take BlackBerry mobile applications to market and stay 
ahead of the curve. Join us from November 9&#45;12, 2009. Register now&#33;
http://p.sf.net/sfu/devconf
_______________________________________________
Mesa3d-dev mailing list
Mesa3d-dev@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/mesa3d-dev

Reply via email to