[Mesa-dev] [PATCH 1/2] gallium: Add a new clip_halfz rasterizer state.

Brian Paul brianp at vmware.com
Mon Apr 22 08:14:52 PDT 2013


On 04/20/2013 04:37 PM, jfonseca at vmware.com wrote:
> From: José Fonseca<jfonseca at vmware.com>
>
> gl_rasterization_rules lumps too many different flags.
> ---
>   src/gallium/auxiliary/draw/draw_context.c          |    1 +
>   src/gallium/auxiliary/draw/draw_llvm.c             |    2 +-
>   src/gallium/auxiliary/draw/draw_pt.h               |    2 +-
>   .../auxiliary/draw/draw_pt_fetch_shade_pipeline.c  |    9 +++------
>   .../draw/draw_pt_fetch_shade_pipeline_llvm.c       |    9 +++------
>   src/gallium/auxiliary/draw/draw_pt_post_vs.c       |    8 ++++----
>   src/gallium/docs/source/cso/rasterizer.rst         |    4 ++++
>   src/gallium/include/pipe/p_state.h                 |    6 ++++++
>   8 files changed, 23 insertions(+), 18 deletions(-)
>
> diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c
> index 0f98021..5272951 100644
> --- a/src/gallium/auxiliary/draw/draw_context.c
> +++ b/src/gallium/auxiliary/draw/draw_context.c
> @@ -712,6 +712,7 @@ draw_get_rasterizer_no_cull( struct draw_context *draw,
>         rast.flatshade = flatshade;
>         rast.front_ccw = 1;
>         rast.gl_rasterization_rules = draw->rasterizer->gl_rasterization_rules;
> +      rast.clip_halfz = draw->rasterizer->clip_halfz;
>
>         draw->rasterizer_no_cull[scissor][flatshade] =
>            pipe->create_rasterizer_state(pipe,&rast);
> diff --git a/src/gallium/auxiliary/draw/draw_llvm.c b/src/gallium/auxiliary/draw/draw_llvm.c
> index e0c0705..e1c08c6 100644
> --- a/src/gallium/auxiliary/draw/draw_llvm.c
> +++ b/src/gallium/auxiliary/draw/draw_llvm.c
> @@ -1669,7 +1669,7 @@ draw_llvm_make_variant_key(struct draw_llvm *llvm, char *store)
>      key->clip_z = llvm->draw->clip_z;
>      key->clip_user = llvm->draw->clip_user;
>      key->bypass_viewport = llvm->draw->identity_viewport;
> -   key->clip_halfz = !llvm->draw->rasterizer->gl_rasterization_rules;
> +   key->clip_halfz = llvm->draw->rasterizer->clip_halfz;
>      key->need_edgeflags = (llvm->draw->vs.edgeflag_output ? TRUE : FALSE);
>      key->ucp_enable = llvm->draw->rasterizer->clip_plane_enable;
>      key->has_gs = llvm->draw->gs.geometry_shader != NULL;
> diff --git a/src/gallium/auxiliary/draw/draw_pt.h b/src/gallium/auxiliary/draw/draw_pt.h
> index 764d311..dca8368 100644
> --- a/src/gallium/auxiliary/draw/draw_pt.h
> +++ b/src/gallium/auxiliary/draw/draw_pt.h
> @@ -233,7 +233,7 @@ void draw_pt_post_vs_prepare( struct pt_post_vs *pvs,
>   			      boolean clip_user,
>                                 boolean guard_band,
>   			      boolean bypass_viewport,
> -			      boolean opengl,
> +                              boolean clip_halfz,
>   			      boolean need_edgeflags );
>
>   struct pt_post_vs *draw_pt_post_vs_create( struct draw_context *draw );
> diff --git a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c
> index e17f161..8e48f46 100644
> --- a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c
> +++ b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c
> @@ -105,17 +105,14 @@ static void fetch_pipeline_prepare( struct draw_pt_middle_end *middle,
>                             vs->info.num_inputs,
>                             fpme->vertex_size,
>                             instance_id_index );
> -   /* XXX: it's not really gl rasterization rules we care about here,
> -    * but gl vs dx9 clip spaces.
> -    */
>      draw_pt_post_vs_prepare( fpme->post_vs,
>   			    draw->clip_xy,
>   			    draw->clip_z,
>   			    draw->clip_user,
>                               draw->guard_band_xy,
> -			    draw->identity_viewport,
> -			    (boolean)draw->rasterizer->gl_rasterization_rules,
> -			    (draw->vs.edgeflag_output ? TRUE : FALSE) );
> +                            draw->identity_viewport,
> +                            draw->rasterizer->clip_halfz,
> +                            (draw->vs.edgeflag_output ? TRUE : FALSE) );
>
>      draw_pt_so_emit_prepare( fpme->so_emit, FALSE );
>
> diff --git a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c
> index d312dc4..4dff4f8 100644
> --- a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c
> +++ b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c
> @@ -156,17 +156,14 @@ llvm_middle_end_prepare( struct draw_pt_middle_end *middle,
>      fpme->vertex_size = sizeof(struct vertex_header) + nr * 4 * sizeof(float);
>
>
> -   /* XXX: it's not really gl rasterization rules we care about here,
> -    * but gl vs dx9 clip spaces.
> -    */
>      draw_pt_post_vs_prepare( fpme->post_vs,
>   			    draw->clip_xy,
>   			    draw->clip_z,
>   			    draw->clip_user,
>                               draw->guard_band_xy,
> -			    draw->identity_viewport,
> -			    (boolean)draw->rasterizer->gl_rasterization_rules,
> -			    (draw->vs.edgeflag_output ? TRUE : FALSE) );
> +                            draw->identity_viewport,
> +                            draw->rasterizer->clip_halfz,
> +                            (draw->vs.edgeflag_output ? TRUE : FALSE) );
>
>      draw_pt_so_emit_prepare( fpme->so_emit, gs == NULL );
>
> diff --git a/src/gallium/auxiliary/draw/draw_pt_post_vs.c b/src/gallium/auxiliary/draw/draw_pt_post_vs.c
> index a83bb59..681a12d 100644
> --- a/src/gallium/auxiliary/draw/draw_pt_post_vs.c
> +++ b/src/gallium/auxiliary/draw/draw_pt_post_vs.c
> @@ -127,14 +127,14 @@ void draw_pt_post_vs_prepare( struct pt_post_vs *pvs,
>                                 boolean clip_user,
>                                 boolean guard_band,
>   			      boolean bypass_viewport,
> -			      boolean opengl,
> +                              boolean clip_halfz,
>   			      boolean need_edgeflags )
>   {
>      pvs->flags = 0;
>
>      /* This combination not currently tested/in use:
>       */
> -   if (opengl)
> +   if (!clip_halfz)
>         guard_band = FALSE;
>
>      if (clip_xy&&  !guard_band) {
> @@ -152,12 +152,12 @@ void draw_pt_post_vs_prepare( struct pt_post_vs *pvs,
>         ASSIGN_4V( pvs->draw->plane[3],  0,  0.5,  0, 1 );
>      }
>
> -   if (clip_z&&  opengl) {
> +   if (clip_z&&  !clip_halfz) {
>         pvs->flags |= DO_CLIP_FULL_Z;
>         ASSIGN_4V( pvs->draw->plane[4],  0,  0,  1, 1 );
>      }
>
> -   if (clip_z&&  !opengl) {
> +   if (clip_z&&  clip_halfz) {
>         pvs->flags |= DO_CLIP_HALF_Z;
>         ASSIGN_4V( pvs->draw->plane[4],  0,  0,  1, 0 );
>      }

I think the above code could be written more clearly as:

   if (clip_z) {
      if (clip_halfz) {
         pvs->flags |= DO_CLIP_HALF_Z;
         ASSIGN_4V( pvs->draw->plane[4],  0,  0,  1, 0 );
      }
      else {
         pvs->flags |= DO_CLIP_FULL_Z;
         ASSIGN_4V( pvs->draw->plane[4],  0,  0,  1, 1 );
      }
   }


> diff --git a/src/gallium/docs/source/cso/rasterizer.rst b/src/gallium/docs/source/cso/rasterizer.rst
> index 8338243..be4bad5 100644
> --- a/src/gallium/docs/source/cso/rasterizer.rst
> +++ b/src/gallium/docs/source/cso/rasterizer.rst
> @@ -242,6 +242,10 @@ gl_rasterization_rules
>       Whether the rasterizer should use (0.5, 0.5) pixel centers. When not set,
>       the rasterizer will use (0, 0) for pixel centers.
>
> +clip_halfz
> +    When true clip space in the z axis goes from [0..1] (D3D).  When false
> +    [-1, 1] (GL)
> +
>   depth_clip
>       When false, the near and far depth clipping planes of the view volume are
>       disabled and the depth value will be clamped at the per-pixel level, after
> diff --git a/src/gallium/include/pipe/p_state.h b/src/gallium/include/pipe/p_state.h
> index dfafd0b..5da3a53 100644
> --- a/src/gallium/include/pipe/p_state.h
> +++ b/src/gallium/include/pipe/p_state.h
> @@ -134,6 +134,12 @@ struct pipe_rasterizer_state
>      unsigned depth_clip:1;
>
>      /**
> +    * When true clip space in the z axis goes from [0..1] (D3D).  When false
> +    * [-1, 1] (GL).
> +    */
> +   unsigned clip_halfz:1;
> +
> +   /**
>       * Enable bits for clipping half-spaces.
>       * This applies to both user clip planes and shader clip distances.
>       * Note that if the bound shader exports any clip distances, these

Looks good otherwise.

Reviewed-by: Brian Paul <brianp at vmware.com>


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