draw: fixes for vertex shaders outputting layer or viewport index

Mostly add a couple cases so we don't just check gs for this.
There's only one gotcha, the built-in vp transform in the llvm vs can't
handle it (this would be fixable though non-trivial due to vp index being
non-constant for the SoA outputs, but we don't use it if there's a gs
neither - the whole clip/vp transform integration there is suboptimal).

Reviewed-by: Jose Fonseca <[email protected]>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c
index bb8c03c36f9..f46f8b42038 100644
--- a/src/gallium/auxiliary/draw/draw_context.c
+++ b/src/gallium/auxiliary/draw/draw_context.c
@@ -806,7 +806,7 @@ draw_current_shader_viewport_index_output(const struct draw_context *draw)
 {
    if (draw->gs.geometry_shader)
       return draw->gs.geometry_shader->viewport_index_output;
-   return 0;
+   return draw->vs.vertex_shader->viewport_index_output;
 }
 
 /**
@@ -818,7 +818,7 @@ draw_current_shader_uses_viewport_index(const struct draw_context *draw)
 {
    if (draw->gs.geometry_shader)
       return draw->gs.geometry_shader->info.writes_viewport_index;
-   return FALSE;
+   return draw->vs.vertex_shader->info.writes_viewport_index;
 }