From 3eef7fec677f40eef1674e44e7ebd836bc7f8612 Mon Sep 17 00:00:00 2001 From: Chris Forbes Date: Sun, 7 Jul 2013 22:22:57 +1200 Subject: [PATCH] i965 Gen4/5: clip: Don't mangle flat varyings This patch ensures that integers will pass through unscathed. Doing (useless) computations on them is risky, especially when their bit patterns correspond to values like inf or nan. [V1-2]: Signed-off-by: Olivier Galibert Signed-off-by: Chris Forbes Reviewed-by: Paul Berry Reviewed-by: Kenneth Graunke --- src/mesa/drivers/dri/i965/brw_clip_util.c | 53 ++++++++++++++--------- 1 file changed, 32 insertions(+), 21 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_clip_util.c b/src/mesa/drivers/dri/i965/brw_clip_util.c index b188bf77384..8500b8b6663 100644 --- a/src/mesa/drivers/dri/i965/brw_clip_util.c +++ b/src/mesa/drivers/dri/i965/brw_clip_util.c @@ -269,28 +269,39 @@ void brw_clip_interp_vertex( struct brw_clip_compile *c, * header), so interpolate: * * New = attr0 + t*attr1 - t*attr0 + * + * Unless the attribute is flat shaded -- in which case just copy + * from one of the sources (doesn't matter which; already copied from pv) */ - struct brw_reg tmp = get_tmp(c); - struct brw_reg t = - c->key.interpolation_mode.mode[slot] == INTERP_QUALIFIER_NOPERSPECTIVE ? - t_nopersp : t0; - - brw_MUL(p, - vec4(brw_null_reg()), - deref_4f(v1_ptr, delta), - t); - - brw_MAC(p, - tmp, - negate(deref_4f(v0_ptr, delta)), - t); - - brw_ADD(p, - deref_4f(dest_ptr, delta), - deref_4f(v0_ptr, delta), - tmp); - - release_tmp(c, tmp); + GLuint interp = c->key.interpolation_mode.mode[slot]; + + if (interp != INTERP_QUALIFIER_FLAT) { + struct brw_reg tmp = get_tmp(c); + struct brw_reg t = + interp == INTERP_QUALIFIER_NOPERSPECTIVE ? t_nopersp : t0; + + brw_MUL(p, + vec4(brw_null_reg()), + deref_4f(v1_ptr, delta), + t); + + brw_MAC(p, + tmp, + negate(deref_4f(v0_ptr, delta)), + t); + + brw_ADD(p, + deref_4f(dest_ptr, delta), + deref_4f(v0_ptr, delta), + tmp); + + release_tmp(c, tmp); + } + else { + brw_MOV(p, + deref_4f(dest_ptr, delta), + deref_4f(v0_ptr, delta)); + } } } -- 2.30.2