[Mesa-dev] [PATCH v2 09/23] glsl: Store info about geometry shaders that emit vertices to non-zero streams.

[Iago Toral Quiroga]

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/mesa/main/mtypes.h     | 2 ++
 src/mesa/main/shaderapi.c  | 1 +
 src/mesa/main/shaderobj.c  | 1 +
 src/mesa/program/program.c | 1 +
 4 files changed, 5 insertions(+)

diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index f45dde4..5bc710e 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;
 };
 
 
@@ -2681,6 +2682,7 @@ 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