draw: make sure clipdistances work with geometry shaders

we were always fetching the info from the vertex shader, but if
geometry shader is present it should be used as the source of
that info.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>

6 files changed, 22 insertions, 2 deletions

diff --git a/src/gallium/auxiliary/draw/draw_cliptest_tmp.h b/src/gallium/auxiliary/draw/draw_cliptest_tmp.h
index 7351559810d..7a385c8d067 100644
--- a/src/gallium/auxiliary/draw/draw_cliptest_tmp.h
+++ b/src/gallium/auxiliary/draw/draw_cliptest_tmp.h
@@ -111,7 +111,8 @@ static boolean TAG(do_cliptest)( struct pt_post_vs *pvs,
 
          if (flags & DO_CLIP_USER) {
             unsigned ucp_mask = ucp_enable;
-            int num_written_clipdistance = pvs->draw->vs.vertex_shader->info.num_written_clipdistance;
+            int num_written_clipdistance =
+               draw_current_shader_num_written_clipdistances(pvs->draw);
             while (ucp_mask) {
                unsigned plane_idx = ffs(ucp_mask)-1;
                ucp_mask &= ~(1 << plane_idx);
diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c
index 35063b94ca4..e8480f6ba73 100644
--- a/src/gallium/auxiliary/draw/draw_context.c
+++ b/src/gallium/auxiliary/draw/draw_context.c
@@ -737,9 +737,20 @@ draw_current_shader_clipvertex_output(const struct draw_context *draw)
 uint
 draw_current_shader_clipdistance_output(const struct draw_context *draw, int index)
 {
+   if (draw->gs.geometry_shader)
+      return draw->gs.geometry_shader->clipdistance_output[index];
    return draw->vs.clipdistance_output[index];
 }
 
+
+uint
+draw_current_shader_num_written_clipdistances(const struct draw_context *draw)
+{
+   if (draw->gs.geometry_shader)
+      return draw->gs.geometry_shader->info.num_written_clipdistance;
+   return draw->vs.vertex_shader->info.num_written_clipdistance;
+}
+
 /**
  * Return a pointer/handle for a driver/CSO rasterizer object which
  * disabled culling, stippling, unfilled tris, etc.
diff --git a/src/gallium/auxiliary/draw/draw_gs.c b/src/gallium/auxiliary/draw/draw_gs.c
index 67e5117c587..74c6279d648 100644
--- a/src/gallium/auxiliary/draw/draw_gs.c
+++ b/src/gallium/auxiliary/draw/draw_gs.c
@@ -791,6 +791,12 @@ draw_create_geometry_shader(struct draw_context *draw,
          gs->position_output = i;
       if (gs->info.output_semantic_name[i] == TGSI_SEMANTIC_VIEWPORT_INDEX)
          gs->viewport_index_output = i;
+      if (gs->info.output_semantic_name[i] == TGSI_SEMANTIC_CLIPDIST) {
+         if (gs->info.output_semantic_index[i] == 0)
+            gs->clipdistance_output[0] = i;
+         else
+            gs->clipdistance_output[1] = i;
+      }
    }
 
    gs->machine = draw->gs.tgsi.machine;
diff --git a/src/gallium/auxiliary/draw/draw_gs.h b/src/gallium/auxiliary/draw/draw_gs.h
index 2b0856924d9..543b32d4202 100644
--- a/src/gallium/auxiliary/draw/draw_gs.h
+++ b/src/gallium/auxiliary/draw/draw_gs.h
@@ -67,6 +67,7 @@ struct draw_geometry_shader {
    struct tgsi_shader_info info;
    unsigned position_output;
    unsigned viewport_index_output;
+   unsigned clipdistance_output[2];
 
    unsigned max_output_vertices;
    unsigned primitive_boundary;
diff --git a/src/gallium/auxiliary/draw/draw_private.h b/src/gallium/auxiliary/draw/draw_private.h
index adde647c4c4..8777e8617f7 100644
--- a/src/gallium/auxiliary/draw/draw_private.h
+++ b/src/gallium/auxiliary/draw/draw_private.h
@@ -389,6 +389,7 @@ uint draw_current_shader_position_output(const struct draw_context *draw);
 uint draw_current_shader_viewport_index_output(const struct draw_context *draw);
 uint draw_current_shader_clipvertex_output(const struct draw_context *draw);
 uint draw_current_shader_clipdistance_output(const struct draw_context *draw, int index);
+uint draw_current_shader_num_written_clipdistances(const struct draw_context *draw);
 int draw_alloc_extra_vertex_attrib(struct draw_context *draw,
                                    uint semantic_name, uint semantic_index);
 void draw_remove_extra_vertex_attribs(struct draw_context *draw);
diff --git a/src/gallium/auxiliary/tgsi/tgsi_scan.c b/src/gallium/auxiliary/tgsi/tgsi_scan.c
index d331257cc4f..872e4ff3a4b 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_scan.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_scan.c
@@ -196,7 +196,7 @@ tgsi_scan_shader(const struct tgsi_token *tokens,
                   info->output_semantic_index[reg] = (ubyte)fulldecl->Semantic.Index;
                   info->num_outputs++;
 
-                  if (procType == TGSI_PROCESSOR_VERTEX &&
+                  if ((procType == TGSI_PROCESSOR_VERTEX || procType == TGSI_PROCESSOR_GEOMETRY) &&
                       fulldecl->Semantic.Name == TGSI_SEMANTIC_CLIPDIST) {
                      info->num_written_clipdistance += util_bitcount(fulldecl->Declaration.UsageMask);
                   }