gallium/draw: add limits to the clip and cull distances

There are strict limits on those registers. Define the maximums
and use them instead of magic numbers. Also allows us to add
some extra sanity checks.
Suggested by Brian.

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

5 files changed, 16 insertions, 14 deletions

diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c
index 0dbddb4..22c0e9b 100644
--- a/src/gallium/auxiliary/draw/draw_context.c
+++ b/src/gallium/auxiliary/draw/draw_context.c
@@ -738,6 +738,7 @@ draw_current_shader_clipvertex_output(const struct draw_context *draw)
 uint
 draw_current_shader_clipdistance_output(const struct draw_context *draw, int index)
 {
+   debug_assert(index < PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT);
    if (draw->gs.geometry_shader)
       return draw->gs.geometry_shader->clipdistance_output[index];
    return draw->vs.clipdistance_output[index];
@@ -756,6 +757,7 @@ draw_current_shader_num_written_clipdistances(const struct draw_context *draw)
 uint
 draw_current_shader_culldistance_output(const struct draw_context *draw, int index)
 {
+   debug_assert(index < PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT);
    if (draw->gs.geometry_shader)
       return draw->gs.geometry_shader->culldistance_output[index];
    return draw->vs.vertex_shader->culldistance_output[index];
diff --git a/src/gallium/auxiliary/draw/draw_gs.c b/src/gallium/auxiliary/draw/draw_gs.c
index b762dd6..cd63e2b 100644
--- a/src/gallium/auxiliary/draw/draw_gs.c
+++ b/src/gallium/auxiliary/draw/draw_gs.c
@@ -792,13 +792,13 @@ draw_create_geometry_shader(struct draw_context *draw,
       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;
+         debug_assert(gs->info.output_semantic_index[i] <
+                      PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT);
+         gs->clipdistance_output[gs->info.output_semantic_index[i]] = i;
       }
       if (gs->info.output_semantic_name[i] == TGSI_SEMANTIC_CULLDIST) {
-         debug_assert(gs->info.output_semantic_index[i] < Elements(gs->culldistance_output));
+         debug_assert(gs->info.output_semantic_index[i] <
+                      PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT);
          gs->culldistance_output[gs->info.output_semantic_index[i]] = i;
       }
    }
diff --git a/src/gallium/auxiliary/draw/draw_gs.h b/src/gallium/auxiliary/draw/draw_gs.h
index 05d666d..e279a80 100644
--- a/src/gallium/auxiliary/draw/draw_gs.h
+++ b/src/gallium/auxiliary/draw/draw_gs.h
@@ -67,8 +67,8 @@ struct draw_geometry_shader {
    struct tgsi_shader_info info;
    unsigned position_output;
    unsigned viewport_index_output;
-   unsigned clipdistance_output[2];
-   unsigned culldistance_output[2];
+   unsigned clipdistance_output[PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT];
+   unsigned culldistance_output[PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT];
 
    unsigned max_output_vertices;
    unsigned primitive_boundary;
diff --git a/src/gallium/auxiliary/draw/draw_vs.c b/src/gallium/auxiliary/draw/draw_vs.c
index a0bebcc..bbccbe4 100644
--- a/src/gallium/auxiliary/draw/draw_vs.c
+++ b/src/gallium/auxiliary/draw/draw_vs.c
@@ -86,12 +86,12 @@ draw_create_vertex_shader(struct draw_context *draw,
             found_clipvertex = TRUE;
             vs->clipvertex_output = i;
          } else if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_CLIPDIST) {
-            if (vs->info.output_semantic_index[i] == 0)
-               vs->clipdistance_output[0] = i;
-            else
-               vs->clipdistance_output[1] = i;
+            debug_assert(vs->info.output_semantic_index[i] <
+                         PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT);
+            vs->clipdistance_output[vs->info.output_semantic_index[i]] = i;
          } else if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_CULLDIST) {
-            debug_assert(vs->info.output_semantic_index[i] < Elements(vs->culldistance_output));
+            debug_assert(vs->info.output_semantic_index[i] <
+                         PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT);
             vs->culldistance_output[vs->info.output_semantic_index[i]] = i;
          }
       }
diff --git a/src/gallium/auxiliary/draw/draw_vs.h b/src/gallium/auxiliary/draw/draw_vs.h
index 7635aba..425efa3 100644
--- a/src/gallium/auxiliary/draw/draw_vs.h
+++ b/src/gallium/auxiliary/draw/draw_vs.h
@@ -112,8 +112,8 @@ struct draw_vertex_shader {
    unsigned position_output;
    unsigned edgeflag_output;
    unsigned clipvertex_output;
-   unsigned clipdistance_output[2];
-   unsigned culldistance_output[2];
+   unsigned clipdistance_output[PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT];
+   unsigned culldistance_output[PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT];
    /* Extracted from shader:
     */
    const float (*immediates)[4];