[Mesa-dev] [PATCH 09/18] glsl: Store info about geometry shaders that emit vertices to non-zero streams.

[Chris Forbes]

I think you need to set this if *any* geometry shader in the program
tries to use a nonzero stream. Currently it looks like the last shader
wins.

On Wed, Jun 11, 2014 at 7:49 PM, Iago Toral Quiroga <itoral at igalia.com> wrote:
> On Intel hardware when a geometry shader outputs GL_POINTS primitives we
> only need to emit vertex control bits if it emits vertices to non-zero
> streams, so use a flag to track this.
>
> This flag will be set to TRUE when a geometry shader calls EmitStreamVertex()
> or EndStreamPrimitive() with a non-zero stream parameter in a later patch.
> ---
>  src/glsl/glsl_parser_extras.cpp | 4 ++++
>  src/glsl/glsl_parser_extras.h   | 5 +++++
>  src/glsl/linker.cpp             | 4 ++++
>  src/mesa/main/mtypes.h          | 6 ++++++
>  src/mesa/main/shaderapi.c       | 1 +
>  src/mesa/main/shaderobj.c       | 1 +
>  src/mesa/program/program.c      | 1 +
>  7 files changed, 22 insertions(+)
>
> diff --git a/src/glsl/glsl_parser_extras.cpp b/src/glsl/glsl_parser_extras.cpp
> index f3c5bd0..b2515e8 100644
> --- a/src/glsl/glsl_parser_extras.cpp
> +++ b/src/glsl/glsl_parser_extras.cpp
> @@ -1407,6 +1407,10 @@ set_shader_inout_layout(struct gl_shader *shader,
>        shader->Geom.Invocations = 0;
>        if (state->in_qualifier->flags.q.invocations)
>           shader->Geom.Invocations = state->in_qualifier->invocations;
> +
> +      shader->Geom.UsesStreams = GL_FALSE;
> +      if (state->gs_uses_streams)
> +         shader->Geom.UsesStreams = GL_TRUE;
>        break;
>
>     case MESA_SHADER_COMPUTE:
> diff --git a/src/glsl/glsl_parser_extras.h b/src/glsl/glsl_parser_extras.h
> index 0416a9c..6610bd7 100644
> --- a/src/glsl/glsl_parser_extras.h
> +++ b/src/glsl/glsl_parser_extras.h
> @@ -447,6 +447,11 @@ struct _mesa_glsl_parse_state {
>      */
>     unsigned gs_input_size;
>
> +   /**
> +    * For geometry shaders, whether non-zero streams are used.
> +    */
> +   bool gs_uses_streams;
> +
>     bool early_fragment_tests;
>
>     /** Atomic counter offsets by binding */
> diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
> index a43d230..7ff7694 100644
> --- a/src/glsl/linker.cpp
> +++ b/src/glsl/linker.cpp
> @@ -1349,6 +1349,8 @@ link_gs_inout_layout_qualifiers(struct gl_shader_program *prog,
>          }
>          linked_shader->Geom.Invocations = shader->Geom.Invocations;
>        }
> +
> +      linked_shader->Geom.UsesStreams = shader->Geom.UsesStreams;
>     }
>
>     /* Just do the intrastage -> interstage propagation right now,
> @@ -1380,6 +1382,8 @@ link_gs_inout_layout_qualifiers(struct gl_shader_program *prog,
>        linked_shader->Geom.Invocations = 1;
>
>     prog->Geom.Invocations = linked_shader->Geom.Invocations;
> +
> +   prog->Geom.UsesStreams = linked_shader->Geom.UsesStreams;
>  }
>
>
> diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
> index 69eb4fa..2519968 100644
> --- a/src/mesa/main/mtypes.h
> +++ b/src/mesa/main/mtypes.h
> @@ -2178,6 +2178,7 @@ struct gl_geometry_program
>                             GL_TRIANGLES, or GL_TRIANGLES_ADJACENCY_ARB */
>     GLenum OutputType; /**< GL_POINTS, GL_LINE_STRIP or GL_TRIANGLE_STRIP */
>     GLboolean UsesEndPrimitive;
> +   GLboolean UsesStreams;
>  };
>
>
> @@ -2473,6 +2474,10 @@ struct gl_shader
>          * it's not set in this shader.
>          */
>        GLenum OutputType;
> +      /**
> +       * Whether this geometry shader uses non-zero vertex streams
> +       */
> +      GLboolean UsesStreams;
>     } Geom;
>
>     /**
> @@ -2681,6 +2686,7 @@ struct gl_shader_program
>        GLuint ClipDistanceArraySize; /**< Size of the gl_ClipDistance array, or
>                                           0 if not present. */
>        GLboolean UsesEndPrimitive;
> +      GLboolean UsesStreams;
>     } Geom;
>
>     /** Vertex shader state */
> diff --git a/src/mesa/main/shaderapi.c b/src/mesa/main/shaderapi.c
> index 2ec2444..2bbef35 100644
> --- a/src/mesa/main/shaderapi.c
> +++ b/src/mesa/main/shaderapi.c
> @@ -1888,6 +1888,7 @@ _mesa_copy_linked_program_data(gl_shader_stage type,
>        dst_gp->OutputType = src->Geom.OutputType;
>        dst->UsesClipDistanceOut = src->Geom.UsesClipDistance;
>        dst_gp->UsesEndPrimitive = src->Geom.UsesEndPrimitive;
> +      dst_gp->UsesStreams = src->Geom.UsesStreams;
>     }
>        break;
>     case MESA_SHADER_FRAGMENT: {
> diff --git a/src/mesa/main/shaderobj.c b/src/mesa/main/shaderobj.c
> index b0f0bfa..03db862 100644
> --- a/src/mesa/main/shaderobj.c
> +++ b/src/mesa/main/shaderobj.c
> @@ -248,6 +248,7 @@ _mesa_init_shader_program(struct gl_context *ctx, struct gl_shader_program *prog
>     prog->Geom.VerticesOut = 0;
>     prog->Geom.InputType = GL_TRIANGLES;
>     prog->Geom.OutputType = GL_TRIANGLE_STRIP;
> +   prog->Geom.UsesStreams = GL_FALSE;
>
>     prog->TransformFeedback.BufferMode = GL_INTERLEAVED_ATTRIBS;
>
> diff --git a/src/mesa/program/program.c b/src/mesa/program/program.c
> index b7332fc..1263cea 100644
> --- a/src/mesa/program/program.c
> +++ b/src/mesa/program/program.c
> @@ -552,6 +552,7 @@ _mesa_clone_program(struct gl_context *ctx, const struct gl_program *prog)
>           gpc->InputType = gp->InputType;
>           gpc->Invocations = gp->Invocations;
>           gpc->OutputType = gp->OutputType;
> +         gpc->UsesStreams = gp->UsesStreams;
>        }
>        break;
>     default:
> --
> 1.9.1
>
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