[Mesa-dev] [PATCH] vbo: introduce vbo_get_minmax_indices function

[Yuanhan Liu]

On Tue, Jan 03, 2012 at 08:25:31PM +0100, Roland Scheidegger wrote:
> Ah index scanning...
> I don't like that this will map/unmap the ib once for each prim,
Me either :)

> though
> I don't really see a nice way to avoid that (I think if you have to

Well, I thought a while, we may do some combine to reduce some
map/unmap.


> actually map the ib, you lose anyway). Hopefully won't hit that
> performance hog often...
> A comment inline.
> 
> 
> Am 31.12.2011 07:32, schrieb Yuanhan Liu:
[snip]...

> > +   for (i = 0; i < nr_prims; i++) {
> > +      tmp_ib.ptr = ib->ptr + prims[i].start * vbo_sizeof_ib_type(ib->type);
> I think you should not use a temporary ib. Figuring out the correct
> start offset clearly looks like it should be handled by
> vbo_get_minmax_index() itself (it should have done this previously
> probably, as there might never have been a guarantee that it is always 0
> even if there's only a single primitive).

Nice suggestion, thanks! Will fix it in the next patch.

--
Yuanhan Liu
> 
> > +      vbo_get_minmax_index(ctx, &prims[i], &tmp_ib, &tmp_min, &tmp_max);
> > +      *min_index = MIN2(*min_index, tmp_min);
> > +      *max_index = MAX2(*max_index, tmp_max);
> > +   }
> > +}
> > +
> >  
> >  /**
> >   * Check that element 'j' of the array has reasonable data.
> 
> Otherwise looks ok to me.
> 
> Roland