[Mesa-dev] [PATCH] vbo: Correctly handle attribute offsets in dlist draw.

[Mathias Fröhlich]

On Friday, 19 August 2016 09:20:41 CEST Erik Faye-Lund wrote:
> On Thu, Aug 18, 2016 at 7:50 PM,  <Mathias.Froehlich at gmx.net> wrote:
> > From: Mathias Fröhlich <mathias.froehlich at web.de>
> >
> > Hi,
> >
> > I found the below while fixing a similar problem lately in
> > the immediate mode glBegin/glEnd code path.
> >
> > Please review
> > Thanks
> >
> > Mathias
> >
> >
> >
> > When executing a display list draw with a shader program
> > using the generic0 attribute the offset computation
> > may get out of sync. To fix precompute the offsets
> > on the full attribute list and store the offsets in
> > the display list node.
> >
> > Signed-off-by: Mathias Fröhlich <Mathias.Froehlich at web.de>
> > ---
> >  src/mesa/vbo/vbo_save.h      |  1 +
> >  src/mesa/vbo/vbo_save_api.c  |  6 ++++++
> >  src/mesa/vbo/vbo_save_draw.c | 35 +++++++++++++++++------------------
> >  3 files changed, 24 insertions(+), 18 deletions(-)
> >
> > diff --git a/src/mesa/vbo/vbo_save.h b/src/mesa/vbo/vbo_save.h
> > index 2843b3c..a61973f 100644
> > --- a/src/mesa/vbo/vbo_save.h
> > +++ b/src/mesa/vbo/vbo_save.h
> > @@ -64,6 +64,7 @@ struct vbo_save_vertex_list {
> >     GLbitfield64 enabled; /**< mask of enabled vbo arrays. */
> >     GLubyte attrsz[VBO_ATTRIB_MAX];
> >     GLenum attrtype[VBO_ATTRIB_MAX];
> > +   GLushort offsets[VBO_ATTRIB_MAX];
> >     GLuint vertex_size;  /**< size in GLfloats */
> >
> >     /* Copy of the final vertex from node->vertex_store->bufferobj.
> > diff --git a/src/mesa/vbo/vbo_save_api.c b/src/mesa/vbo/vbo_save_api.c
> > index f648ccc..4473fef 100644
> > --- a/src/mesa/vbo/vbo_save_api.c
> > +++ b/src/mesa/vbo/vbo_save_api.c
> > @@ -436,6 +436,12 @@ _save_compile_vertex_list(struct gl_context *ctx)
> >     node->vertex_size = save->vertex_size;
> >     node->buffer_offset =
> >        (save->buffer - save->vertex_store->buffer) * sizeof(GLfloat);
> > +   GLushort offset = 0;
> > +   int i;
> > +   for (i = 0; i < VBO_ATTRIB_MAX; ++i) {
> > +      node->offsets[i] = offset;
> > +      offset += node->attrsz[i] * sizeof(GLfloat);
> > +   }
> 
> I'm not sure what the policy regarding C99 is ATM, but this seems to
> introduce declaration-after-statement for the first time in this
> source.

Someone requested lately in a review that I should declare variables where I 
use them the first time. To my following question, if this is now a treewide 
policy, I got no answer. IIRC the file in question was some mesa core file.
I can easily change my personal coding back to 'adapt to the surronding code 
style' what I usually do for patches in any other project I contribute to and 
what I did on mesa before I got the request to start moving to somewhere else.
Any official policy?

best
Mathias