[Mesa-dev] Mesa (master): draw: fix flat shading and screen-space linear interpolation in clipper

[Olivier Galibert]

On Fri, Jun 29, 2012 at 03:09:23PM -0700, Stéphane Marchesin wrote:
> I do, but it fixes a regression, so unless you have a fix, it's the way to
> go. If you have a fix I'll happily test it :)

Just between us, revert on small regressions may not be optimal long
term on a project like mesa where the review/commit pipeline is
clogged.  The risk of losing developers is non-negligible.  The linux
kernel can afford it because even if you miss a cycle you know that
you will have another one in two months, and there are a lot of
intermediate collation trees in which your patch can be tried out and
shaken for bugs (subsystem trees, -next, akp patch tree, etc).  I'm
not sure Mesa can afford it.

That said, try this.

commit 56555c58d7f16c8d619c21feb23096155e2fb505
Author: Olivier Galibert <galibert at pobox.com>
Date:   Sat Jun 30 00:41:20 2012 +0200

    lp_bld_tgsi_soa: Fix conversion of system values to float.
    
    Signed-off-by: Olivier Galibert <galibert at pobox.com>

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
index 55db561..f8df2bc 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
@@ -811,9 +811,10 @@ emit_fetch_system_value(
       break;
    }
 
+   /* Extend that when atype can happen to be float */
    if (atype != stype) {
       if (stype == TGSI_TYPE_FLOAT) {
-         res = LLVMBuildBitCast(builder, res, bld_base->base.vec_type, "");
+         res = lp_build_int_to_float(&bld_base->base, res);
       } else if (stype == TGSI_TYPE_UNSIGNED) {
          res = LLVMBuildBitCast(builder, res, bld_base->uint_bld.vec_type, "");
       } else if (stype == TGSI_TYPE_SIGNED) {