Re: [Mesa3d-dev] Probably, i monkeyed in wrong direction .....

[<ran...@gm...>]

В сообщении от Friday 05 March 2010 23:49:03 Stephane Marchesin написал(а):
> 2010/3/5  <ran...@gm...>:
> > В сообщении от Friday 05 March 2010 16:55:20 Jesse Barnes написал(а):
> >> make realclean and configure and make again.
> >
> > Removing all new functions and reverting to mainstream mesa works OK,
> > even without realclean ... So, it is purely my fault, as coder. But what
> > exactly I forgot? Init current_primitive = -1 on context creation?  State
> > management in nouveau changed since first dri1 attempt ....
> >
> > As far as i understand this code - you  plug in not just fev line
> > functions but two big function tables, filled with many functions
> > (pointers at functions). This way one can plug in much more optimized
> > (for different OpenGL cases) render functions, if hw permits this. So,
> > you plug inly one "Chooser" function into mesa's TNL module, and  keep
> > current primitive type somewhere in your context data .....
> >
> > Ideally, various fixups (like polygonOffset) will be layred on top of
> > this, making nv04.render.c a bit hard for reading ...
> >
> > Thanks Jesse and Francisco for your time, you spended reading my mails
> > and trying to figure out what was my fault ....
>
> As discussed on irc, and for posterity:
>
> 00:35 < marcheu> you have a 16 or 8 (with multitexture) vertex cache
> 00:35 < marcheu> these number you see (0xFEDCBA) are not magic
> 00:35 < marcheu> these are the index of the vertices we want to emit
> 00:36 < marcheu> so FEDCBA emits vertices 15,14,13,12,11 and 10
> 00:36 < marcheu> but that means you have to actually place data at
> these locations
> 00:37 < marcheu> which means that if you want to do a single-pass
> emission you have to place the first vertex at spot 10
> 00:37 < marcheu> so basically the layout of the nv4 3D object is like that:
> 00:37 < marcheu> - vertex 0
> 00:37 < marcheu> - vertex 1
> 00:37 < marcheu> ...
> 00:37 < marcheu> - vertex 15
> 00:38 < marcheu> - vertex indices that we want fired
> 00:38 < marcheu> so if you want to do a 1-swoop submission, you have
> to start from 10 or so
> 00:38 < marcheu> that also means you _place_ vertex data at the right
> spot. right now you place it at 0
> 00:39 < marcheu> also you reserve one too little places on the fifo (6
> instead of 7 on line 206)
> 00:39 < marcheu> becuase you need one spot for the FEDCBA
> 00:39 < marcheu> so you need 3 things:
> 00:39 < marcheu> - start emitting at the right place, which probably
> means an extra argument to BEGIN_PRIMITIVE to tell which place
> 00:40 < marcheu> - increase the size of the BEGIN_PRIMITIVE
> 00:40 < marcheu> - that was only two things :)
>
> Stephane

New patch is here, tested with trivial/tri, DANGEROUS, may lock up your 
machine hard with anything else!

Strange thing about code - in function swtnl_render_triangles_verts it was 
going on and on, causing segfault, until i added

if (count == 3)
	{
	swtnl_triangle(ctx, i+0,i+1,i+2);
	return;
	}


Was found under gdb

=======

swtnl_render_triangles_verts (ctx=0x950ca88, start=0, count=3, flags=52)
    at nv04_render.c:285
285             for(i=start;i<count-5;i+=6)
(gdb) print i
$1 = 18

=======

Please, someone, enlight me on this small C secret, what was wrong in this 
for() ?