[Mesa-dev] [PATCH] draw: fix splitting of line loops

[Roland Scheidegger]

I thought just changing the prim type would cause the loop to not get
closed in the end, albeit I looked at it only briefly (I thought the
DRAW_SPLIT_AFTER/BEFORE flags were supposed to be able to deal with this
but couldn't figure out how). But if this works correctly,

Reviewed-by: Roland Scheidegger <sroland at vmware.com>

Am 17.10.2015 um 20:27 schrieb Brian Paul:
> When the draw module splits long line loops, the sections are emitted
> as line strips.  But the primitive type wasn't set correctly so each
> section was being drawn as a loop, introducing extra line segments.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=81174
> ---
>  src/gallium/auxiliary/draw/draw_pt_vsplit.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/src/gallium/auxiliary/draw/draw_pt_vsplit.c b/src/gallium/auxiliary/draw/draw_pt_vsplit.c
> index 8d448f9..02f7e71 100644
> --- a/src/gallium/auxiliary/draw/draw_pt_vsplit.c
> +++ b/src/gallium/auxiliary/draw/draw_pt_vsplit.c
> @@ -256,8 +256,11 @@ static void vsplit_prepare(struct draw_pt_front_end *frontend,
>        break;
>     }
>  
> -   /* split only */
> -   vsplit->prim = in_prim;
> +   /* Line loops get split into line strips. Other types stay as-is. */
> +   if (in_prim == PIPE_PRIM_LINE_LOOP)
> +      vsplit->prim = PIPE_PRIM_LINE_STRIP;
> +   else
> +      vsplit->prim = in_prim;
>  
>     vsplit->middle = middle;
>     middle->prepare(middle, vsplit->prim, opt, &vsplit->max_vertices);
>