void vrend_texture_barrier(UNUSED struct vrend_context *ctx,
                           unsigned flags)
{
   if (has_feature(feat_texture_barrier) && (flags & PIPE_TEXTURE_BARRIER_SAMPLER))
      glTextureBarrier();
   if (has_feature(feat_blend_equation_advanced) && (flags & PIPE_TEXTURE_BARRIER_FRAMEBUFFER))
      glBlendBarrierKHR();
}
void vrend_texture_barrier(UNUSED struct vrend_context *ctx,
                           unsigned flags)
{
   if (has_feature(feat_texture_barrier) && (flags & PIPE_TEXTURE_BARRIER_SAMPLER))
      glTextureBarrier();
   if (has_feature(feat_blend_equation_advanced) && (flags & PIPE_TEXTURE_BARRIER_FRAMEBUFFER))
      glBlendBarrierKHR();
}