[Mesa-dev] [PATCH 4/4] gallium: Enable ARB_clip_control for gallium drivers.

[Roland Scheidegger]

Am 22.10.2014 um 07:31 schrieb Mathias.Froehlich at gmx.net:
> From: Mathias Fröhlich <Mathias.Froehlich at gmx.net>
> 
> Gallium should be prepared fine for ARB_clip_control.
> So enable this and mention it in the release notes.
> 
> Signed-off-by: Mathias Froehlich <Mathias.Froehlich at web.de>
> ---
>  docs/GL3.txt                                |  2 +-
>  docs/relnotes/10.4.html                     |  1 +
>  src/mesa/state_tracker/st_atom_rasterizer.c | 14 +++++++++++++-
>  src/mesa/state_tracker/st_extensions.c      |  1 +
>  4 files changed, 16 insertions(+), 2 deletions(-)
> 
> diff --git a/docs/GL3.txt b/docs/GL3.txt
> index 07d1d2c..2fe0da1 100644
> --- a/docs/GL3.txt
> +++ b/docs/GL3.txt
> @@ -187,7 +187,7 @@ GL 4.4, GLSL 4.40:
>  GL 4.5, GLSL 4.50:
>  
>    GL_ARB_ES3_1_compatibility                           not started
> -  GL_ARB_clip_control                                  not started
> +  GL_ARB_clip_control                                  DONE (gallium drivers)
>    GL_ARB_conditional_render_inverted                   DONE (i965, nvc0, llvmpipe, softpipe)
>    GL_ARB_cull_distance                                 not started
>    GL_ARB_derivative_control                            DONE (i965, nv50, nvc0, r600)
> diff --git a/docs/relnotes/10.4.html b/docs/relnotes/10.4.html
> index 64cbfae..462eeb5 100644
> --- a/docs/relnotes/10.4.html
> +++ b/docs/relnotes/10.4.html
> @@ -46,6 +46,7 @@ Note: some of the new features are only available with certain drivers.
>  <ul>
>  <li>GL_ARB_sample_shading on r600</li>
>  <li>GL_ARB_texture_view on nv50, nvc0</li>
> +<li>GL_ARB_clip_control on gallium drivers</li>
>  </ul>
>  
>  
> diff --git a/src/mesa/state_tracker/st_atom_rasterizer.c b/src/mesa/state_tracker/st_atom_rasterizer.c
> index a228538..050160d 100644
> --- a/src/mesa/state_tracker/st_atom_rasterizer.c
> +++ b/src/mesa/state_tracker/st_atom_rasterizer.c
> @@ -71,6 +71,11 @@ static void update_raster_state( struct st_context *st )
>     {
>        raster->front_ccw = (ctx->Polygon.FrontFace == GL_CCW);
>  
> +      /* _NEW_VIEWPORT */
> +      if (ctx->ClipControl.Origin == GL_UPPER_LEFT) {
> +         raster->front_ccw ^= 1;
> +      }
> +
>        /*
>         * Gallium's surfaces are Y=0=TOP orientation.  OpenGL is the
>         * opposite.  Window system surfaces are Y=0=TOP.  Mesa's FBOs
> @@ -234,6 +239,12 @@ static void update_raster_state( struct st_context *st )
>     raster->half_pixel_center = 1;
>     if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP)
>        raster->bottom_edge_rule = 1;
> +   /* _NEW_VIEWPORT */
> +   if (ctx->ClipControl.Origin == GL_UPPER_LEFT)
> +      raster->bottom_edge_rule ^= 1;
> +
> +   /* _NEW_VIEWPORT */
> +   raster->clip_halfz = (ctx->ClipControl.Depth == GL_ZERO_TO_ONE);
>  
>     /* ST_NEW_RASTERIZER */
>     raster->rasterizer_discard = ctx->RasterDiscard;
> @@ -265,7 +276,8 @@ const struct st_tracked_state st_update_rasterizer = {
>         _NEW_PROGRAM |
>         _NEW_SCISSOR |
>         _NEW_FRAG_CLAMP |
> -       _NEW_TRANSFORM),      /* mesa state dependencies*/
> +       _NEW_TRANSFORM |
> +       _NEW_VIEWPORT),      /* mesa state dependencies*/
>        (ST_NEW_VERTEX_PROGRAM |
>         ST_NEW_RASTERIZER),  /* state tracker dependencies */
>     },
> diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
> index 5dd8278..e22347b 100644
> --- a/src/mesa/state_tracker/st_extensions.c
> +++ b/src/mesa/state_tracker/st_extensions.c
> @@ -585,6 +585,7 @@ void st_init_extensions(struct pipe_screen *screen,
>      * Extensions that are supported by all Gallium drivers:
>      */
>     extensions->ARB_ES2_compatibility = GL_TRUE;
> +   extensions->ARB_clip_control = GL_TRUE;
>     extensions->ARB_draw_elements_base_vertex = GL_TRUE;
>     extensions->ARB_explicit_attrib_location = GL_TRUE;
>     extensions->ARB_explicit_uniform_location = GL_TRUE;
> 

I agree with Marek this should have a cap bit if not all drivers support
it (we got away without it as only some non-public state tracker used it
which only got used with some drivers, but exposing this in GL is
different).

Roland