Test fails with following error:
ERROR:transform_feedback_vertex_id:compareArrays(GLint):index 0 value 4 != 0
Found on further investigation that intel hardware always sets the VertexID starting from 0, irrespective of the first index specified in glDrawArrays(mode, first, count). Seems like this issue is present on multiple Intel platforms (gen6,7,8). We need a software workaround to provide vertex shader with correct gl_VertexID values.
I'm working on this now. I'll also make a piglit test.
This was fixed, just verified this with IVB and Mesa master (e1c50ab)
--- 8< ------------------
Author: Ian Romanick <firstname.lastname@example.org>
Date: Fri Jun 20 16:26:35 2014 -0700
i965: Request lowering gl_VertexID
Fixes the (new) piglit tests gles-3.0-drawarrays-vertexid,
gl-3.0-multidrawarrays-vertexid, and gl-3.2-basevertex-vertexid.
Fixes gles3conform failure in:
Signed-off-by: Ian Romanick <email@example.com>
Reviewed-by: Kenneth Graunke <firstname.lastname@example.org>
on Feb 24, 2017 at 21:52:11.
(provided by the Example extension).