st/mesa: simplify determination whether a draw needs min/max index

Reviewed-by: Mathias Fröhlich <[email protected]>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3829>

1 files changed, 14 insertions, 0 deletions

diff --git a/src/mesa/main/arrayobj.h b/src/mesa/main/arrayobj.h
index 584e6d818cf..19ab65b3242 100644
--- a/src/mesa/main/arrayobj.h
+++ b/src/mesa/main/arrayobj.h
@@ -212,6 +212,20 @@ _mesa_draw_user_array_bits(const struct gl_context *ctx)
 
 
 /**
+ * Return which enabled vertex attributes have a non-zero instance divisor.
+ *
+ * Needs the a fully updated VAO ready for draw.
+ */
+static inline GLbitfield
+_mesa_draw_nonzero_divisor_bits(const struct gl_context *ctx)
+{
+   const struct gl_vertex_array_object *const vao = ctx->Array._DrawVAO;
+   assert(vao->NewArrays == 0);
+   return ~vao->_EffEnabledNonZeroDivisor & ctx->Array._DrawVAOEnabledAttribs;
+}
+
+
+/**
  * Return enabled current values attribute bits for draw.
  */
 static inline GLbitfield