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authorZou Nan hai <nanhai.zou@intel.com>2008-02-14 10:12:03 +0800
committerZou Nan hai <nanhai.zou@intel.com>2008-02-14 10:12:03 +0800
commit08fd2488b011db78ebf7eafbf6ea61d5444ffe7c (patch)
tree42c24534f3b7dd986100e5c571a44ff0ab87aa57
parenteb9da9706ee060a8e4bb5c4fa133ab06dc6b5a53 (diff)
[i965] gl_FrontFacing support
-rw-r--r--src/mesa/drivers/dri/i965/brw_sf_emit.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_sf_emit.c b/src/mesa/drivers/dri/i965/brw_sf_emit.c
index 080a02b730..ad1527e519 100644
--- a/src/mesa/drivers/dri/i965/brw_sf_emit.c
+++ b/src/mesa/drivers/dri/i965/brw_sf_emit.c
@@ -59,6 +59,35 @@ static GLboolean have_attr(struct brw_sf_compile *c,
return (c->key.attrs & (1<<attr)) ? 1 : 0;
}
+/**
+ * Sets VERT_RESULT_FOGC.Y for gl_FrontFacing
+ *
+ * This is currently executed if the fragment program uses VERT_RESULT_FOGC
+ * at all, but this could be eliminated with a scan of the FP contents.
+ */
+static void
+do_front_facing( struct brw_sf_compile *c )
+{
+ struct brw_compile *p = &c->func;
+ int i;
+
+ if (!have_attr(c, VERT_RESULT_FOGC))
+ return;
+
+ brw_push_insn_state(p);
+ brw_CMP(p, brw_null_reg(),
+ c->key.frontface_ccw ? BRW_CONDITIONAL_G : BRW_CONDITIONAL_L,
+ c->det, brw_imm_f(0));
+ brw_set_predicate_control(p, BRW_PREDICATE_NONE);
+ for (i = 0; i < 3; i++) {
+ struct brw_reg fogc = get_vert_attr(c, c->vert[i],FRAG_ATTRIB_FOGC);
+ brw_MOV(p, get_element(fogc, 1), brw_imm_f(0));
+ brw_set_predicate_control(p, BRW_PREDICATE_NORMAL);
+ brw_MOV(p, get_element(fogc, 1), brw_imm_f(1));
+ brw_set_predicate_control(p, BRW_PREDICATE_NONE);
+ }
+ brw_pop_insn_state(p);
+}
/***********************************************************************
@@ -355,6 +384,7 @@ void brw_emit_tri_setup( struct brw_sf_compile *c, GLboolean allocate)
invert_det(c);
copy_z_inv_w(c);
+ do_front_facing(c);
if (c->key.do_twoside_color)
do_twoside_color(c);