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authorChris Forbes <chrisf@ijw.co.nz>2013-07-07 22:22:57 +1200
committerChris Forbes <chrisf@ijw.co.nz>2013-08-01 20:59:03 +1200
commit3eef7fec677f40eef1674e44e7ebd836bc7f8612 (patch)
tree6343931222b5d3b0ad57c314cdffd996c8dbaa58 /src/mesa/drivers/dri
parent3f6fb5e1dd684434979ffca418184574e5c086f3 (diff)
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 <galibert at pobox.com> Signed-off-by: Chris Forbes <chrisf@ijw.co.nz> Reviewed-by: Paul Berry <stereotype441@gmail.com> Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Diffstat (limited to 'src/mesa/drivers/dri')
-rw-r--r--src/mesa/drivers/dri/i965/brw_clip_util.c53
1 files 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 b188bf7738..8500b8b666 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));
+ }
}
}