glsl: Store info about geometry shaders that emit vertices to non-zero streams.

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.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

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 */
    bool UsesEndPrimitive;
+   bool UsesStreams;
 };
 
 
@@ -2681,6 +2682,7 @@ struct gl_shader_program
       GLuint ClipDistanceArraySize; /**< Size of the gl_ClipDistance array, or
                                          0 if not present. */
       bool UsesEndPrimitive;
+      bool UsesStreams;
    } Geom;
 
    /** Vertex shader state */

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: {

src/mesa/main/shaderobj.c

@@ -249,6 +249,7 @@ _mesa_init_shader_program(struct gl_context *ctx, struct gl_shader_program *prog
    prog->Geom.InputType = GL_TRIANGLES;
    prog->Geom.OutputType = GL_TRIANGLE_STRIP;
    prog->Geom.UsesEndPrimitive = false;
+   prog->Geom.UsesStreams = false;
 
    prog->TransformFeedback.BufferMode = GL_INTERLEAVED_ATTRIBS;
 

src/mesa/program/program.c

@@ -553,6 +553,7 @@ _mesa_clone_program(struct gl_context *ctx, const struct gl_program *prog)
          gpc->Invocations = gp->Invocations;
          gpc->OutputType = gp->OutputType;
          gpc->UsesEndPrimitive = gp->UsesEndPrimitive;
+         gpc->UsesStreams = gp->UsesStreams;
       }
       break;
    default: