From: Antia Puentes <apuentes@igalia.com>
Date: Thu, 28 Feb 2019 18:07:36 +0000 (+0100)
Subject: nir/spirv: Fix gl_BaseVertex for non-indexed draws for OpenGL
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=954224b7147e8197555856d9833e8cfb2342d4d5;p=mesa.git

nir/spirv: Fix gl_BaseVertex for non-indexed draws for OpenGL

Lowers BaseVertex to the correct system value for OpenGL.

v2: use options->environment rather than adding a new flag to
    spirv_to_nir_options

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
---

diff --git a/src/compiler/spirv/vtn_variables.c b/src/compiler/spirv/vtn_variables.c
index d4e3cac5db3..843801cae5a 100644
--- a/src/compiler/spirv/vtn_variables.c
+++ b/src/compiler/spirv/vtn_variables.c
@@ -1411,9 +1411,12 @@ vtn_get_builtin_location(struct vtn_builder *b,
       break;
    case SpvBuiltInBaseVertex:
       /* OpenGL gl_BaseVertex (SYSTEM_VALUE_BASE_VERTEX) is not the same
-       * semantic as SPIR-V BaseVertex (SYSTEM_VALUE_FIRST_VERTEX).
+       * semantic as Vulkan BaseVertex (SYSTEM_VALUE_FIRST_VERTEX).
        */
-      *location = SYSTEM_VALUE_FIRST_VERTEX;
+      if (b->options->environment == NIR_SPIRV_OPENGL)
+         *location = SYSTEM_VALUE_BASE_VERTEX;
+      else
+         *location = SYSTEM_VALUE_FIRST_VERTEX;
       set_mode_system_value(b, mode);
       break;
    case SpvBuiltInBaseInstance: