softpipe: fix streamout with an emptry geometry shader

Same approach as in the llvmpipe, if the geometry shader is
null and we have stream output then attach it to the vertex
shader right before executing the draw pipeline.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: José Fonseca <jfonseca@vmware.com>

2 files changed, 23 insertions, 12 deletions

diff --git a/src/gallium/drivers/softpipe/sp_draw_arrays.c b/src/gallium/drivers/softpipe/sp_draw_arrays.c
index 4378312..0eb9c50 100644
--- a/src/gallium/drivers/softpipe/sp_draw_arrays.c
+++ b/src/gallium/drivers/softpipe/sp_draw_arrays.c
@@ -105,6 +105,13 @@ softpipe_draw_vbo(struct pipe_context *pipe,
    draw_set_mapped_so_targets(draw, sp->num_so_targets,
                               sp->so_targets);
 
+   if (sp->gs && !sp->gs->shader.tokens) {
+      /* we have an empty geometry shader with stream output, so
+         attach the stream output info to the current vertex shader */
+      if (sp->vs) {
+         draw_vs_attach_so(sp->vs->draw_data, &sp->gs->shader.stream_output);
+      }
+   }
    draw_collect_pipeline_statistics(draw,
                                     sp->active_statistics_queries > 0);
 
diff --git a/src/gallium/drivers/softpipe/sp_state_shader.c b/src/gallium/drivers/softpipe/sp_state_shader.c
index 40d32a4..79bd597 100644
--- a/src/gallium/drivers/softpipe/sp_state_shader.c
+++ b/src/gallium/drivers/softpipe/sp_state_shader.c
@@ -275,21 +275,25 @@ softpipe_create_gs_state(struct pipe_context *pipe,
    if (state == NULL )
       goto fail;
 
-   /* debug */
-   if (softpipe->dump_gs)
-      tgsi_dump(templ->tokens, 0);
+   state->shader = *templ;
 
-   /* copy shader tokens, the ones passed in will go away.
-    */
-   state->shader.tokens = tgsi_dup_tokens(templ->tokens);
-   if (state->shader.tokens == NULL)
-      goto fail;
+   if (templ->tokens) {
+      /* debug */
+      if (softpipe->dump_gs)
+         tgsi_dump(templ->tokens, 0);
 
-   state->draw_data = draw_create_geometry_shader(softpipe->draw, templ);
-   if (state->draw_data == NULL)
-      goto fail;
+      /* copy shader tokens, the ones passed in will go away.
+       */
+      state->shader.tokens = tgsi_dup_tokens(templ->tokens);
+      if (state->shader.tokens == NULL)
+         goto fail;
 
-   state->max_sampler = state->draw_data->info.file_max[TGSI_FILE_SAMPLER];
+      state->draw_data = draw_create_geometry_shader(softpipe->draw, templ);
+      if (state->draw_data == NULL)
+         goto fail;
+
+      state->max_sampler = state->draw_data->info.file_max[TGSI_FILE_SAMPLER];
+   }
 
    return state;