On Friday, June 26, 2015 04:17:39 PM Jason Ekstrand wrote:
> On Fri, Jun 26, 2015 at 3:56 PM, Kenneth Graunke <kenn...@whitecape.org>
> wrote:
> > Legacy user clipping (using gl_Position or gl_ClipVertex) is handled by
> > turning those into the modern gl_ClipDistance equivalents.
> >
> > This is unnecessary in Core Profile: if user clipping is enabled, but
> > the shader doesn't write the corresponding gl_ClipDistance entry,
> > results are undefined. Hence, it is also unnecessary for geometry
> > shaders.
> >
> > This patch moves the call up to run_vs(). This is equivalent for VS,
> > but removes the need to pass clip distances into emit_urb_writes().
> >
> > Signed-off-by: Kenneth Graunke <kenn...@whitecape.org>
> > ---
> > src/mesa/drivers/dri/i965/brw_fs.cpp | 4 +++-
> > src/mesa/drivers/dri/i965/brw_fs.h | 2 +-
> > src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 16 +++++++++++-----
> > 3 files changed, 15 insertions(+), 7 deletions(-)
> >
> > diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp
> > b/src/mesa/drivers/dri/i965/brw_fs.cpp
> > index 4292aa6..8658554 100644
> > --- a/src/mesa/drivers/dri/i965/brw_fs.cpp
> > +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
> > @@ -3816,7 +3816,9 @@ fs_visitor::run_vs(gl_clip_plane *clip_planes)
> > if (failed)
> > return false;
> >
> > - emit_urb_writes(clip_planes);
> > + compute_clip_distance(clip_planes);
> > +
> > + emit_urb_writes();
> >
> > if (shader_time_index >= 0)
> > emit_shader_time_end();
> > diff --git a/src/mesa/drivers/dri/i965/brw_fs.h
> > b/src/mesa/drivers/dri/i965/brw_fs.h
> > index 243baf6..d08d438 100644
> > --- a/src/mesa/drivers/dri/i965/brw_fs.h
> > +++ b/src/mesa/drivers/dri/i965/brw_fs.h
> > @@ -271,7 +271,7 @@ public:
> > fs_reg src0_alpha, unsigned components,
> > unsigned exec_size, bool use_2nd_half =
> > false);
> > void emit_fb_writes();
> > - void emit_urb_writes(gl_clip_plane *clip_planes);
> > + void emit_urb_writes();
> > void emit_cs_terminate();
> >
> > void emit_barrier();
> > diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
> > b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
> > index 7074b5c..854e49b 100644
> > --- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
> > +++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
> > @@ -1730,6 +1730,12 @@
> > fs_visitor::setup_uniform_clipplane_values(gl_clip_plane *clip_planes)
> > }
> > }
> >
> > +/**
> > + * Lower legacy fixed-function and gl_ClipVertex clipping to clip
> > distances.
> > + *
> > + * This does nothing if the shader uses gl_ClipDistance or user clipping is
> > + * disabled altogether.
> > + */
> > void fs_visitor::compute_clip_distance(gl_clip_plane *clip_planes)
> > {
> > struct brw_vue_prog_data *vue_prog_data =
> > @@ -1737,6 +1743,10 @@ void fs_visitor::compute_clip_distance(gl_clip_plane
> > *clip_planes)
> > const struct brw_vue_prog_key *key =
> > (const struct brw_vue_prog_key *) this->key;
> >
> > + /* Bail unless some sort of legacy clipping is enabled */
> > + if (!key->userclip_active || prog->UsesClipDistanceOut)
> > + return;
> > +
>
> Any reason why you changed this from a conditional call to
> compute_clip_distance to an early return? I don't know that I care
> much either way.
>
> Thanks for making this less gross.
>
> Reviewed-by: Jason Ekstrand <jason.ekstr...@intel.com>I did it that way because compute_clip_distances() already prods at brw_vue_prog_key, and run_vs() currently doesn't. I would have had to introduce key casts there. I felt the unconditional call kept run_vs() less cluttered, too. Either way would work.
signature.asc
Description: This is a digitally signed message part.
_______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
