From: Ian Jackson <ian@liberator.relativity.greenend.org.uk>
Date: Sat, 19 Feb 2011 12:23:35 +0000 (+0000)
Subject: safety: movpos: new function movposcomb_feature_posn
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ijackson/git?p=trains.git;a=commitdiff_plain;h=fe3d5809b4a1f0b8186d3e3fb76dc36ef6d08718

safety: movpos: new function movposcomb_feature_posn
---

diff --git a/hostside/movpos.c b/hostside/movpos.c
index 2d05b3c..75a139d 100644
--- a/hostside/movpos.c
+++ b/hostside/movpos.c
@@ -131,6 +131,11 @@ static void ouposn_feat(const Segment *move, const MovFeatInfo *feati,
 	   feati->pname, posn, m->pname);
 }
 
+int movposcomb_feature_posn(const MovFeatInfo *feati, MovPosComb comb) {
+  /* Returns position of individual feature. */
+  return (comb / feati->weight) % feati->posns;
+}
+
 MovPosComb movposcomb_feature_update(const MovFeatInfo *mfi,
 				     MovPosComb startpoint, int featpos) {
   MovPosComb above_weight= mfi->weight * mfi->posns;
diff --git a/hostside/safety.h b/hostside/safety.h
index 83b570c..ff58d96 100644
--- a/hostside/safety.h
+++ b/hostside/safety.h
@@ -241,11 +241,16 @@ MovPosComb movpos_change_intent(MovPosChange *chg);
 
 const char *movpos_pname(const Segment *move, MovPosComb poscomb);
 
+
+/* Pure functions for manipulating MovPosComb values: */
+
+int movposcomb_feature_posn(const MovFeatInfo *mfi, MovPosComb comb);
+  /* Returns position of individual feature. */
+
 MovPosComb movposcomb_feature_update(const MovFeatInfo *mfi,
 				     MovPosComb startpoint,
 				     int featpos);
-  /* Returns movposcomb representing a changed combination of positions;
-   * pure function. */
+  /* Returns movposcomb representing a changed combination of positions */
 
 /*========== speed.c ==========*/