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>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c
index 0dbddb4511..22c0e9be99 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];