From: Kaj-Michael Lang <milang@tal.org>
Date: Wed, 9 Apr 2008 08:31:52 +0000 (+0300)
Subject: Add simple angle diff function
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1e8de1329b814b2034934eab0c69a61f5e26a3e0;p=mapper

Add simple angle diff function
---

diff --git a/src/latlon.c b/src/latlon.c
index 8827dc1..943510c 100644
--- a/src/latlon.c
+++ b/src/latlon.c
@@ -56,6 +56,20 @@ UNITS_TEXT[UNITS_MI] = _("mi.");
 UNITS_TEXT[UNITS_NM] = _("n.m.");
 }
 
+gfloat
+angle_diff(gfloat a, gfloat b)
+{
+gfloat tmax, tmin, t;
+
+tmax=MAX(a,b);
+tmin=MIN(a,b);
+
+t=tmax-tmin;
+if (t>180) t-=360;
+
+return t;
+}
+
 static inline gdouble 
 magnitude(gdouble x1, gdouble y1, gdouble x2, gdouble y2)
 {
@@ -244,34 +258,27 @@ gdouble acoor=fabs(coor);
 switch (degformat) {
 	case DDPDDDDD:
 		g_sprintf(scoor, "%.5f°", coor);
-		break;
+	break;
 	case DDPDDDDD_NSEW:
-		g_sprintf(scoor, "%.5f° %c", acoor,
-			coor < 0.f ? neg_char : pos_char);
-		break;
-
+		g_sprintf(scoor, "%.5f° %c", acoor, coor < 0.f ? neg_char : pos_char);
+	break;
 	case DD_MMPMMM:
-		g_sprintf(scoor, "%d°%06.3f'",
-			(int)coor, (acoor - (int)acoor) * 60.0);
-		break;
+		g_sprintf(scoor, "%d°%06.3f'",	(int)coor, (acoor - (int)acoor) * 60.0);
+	break;
 	case DD_MMPMMM_NSEW:
-		g_sprintf(scoor, "%d°%06.3f' %c",
-			(int)acoor, (acoor - (int)acoor) * 60.0,
-			coor < 0.f ? neg_char : pos_char);
-		break;
-
+		g_sprintf(scoor, "%d°%06.3f' %c", (int)acoor, (acoor - (int)acoor) * 60.0,	coor < 0.f ? neg_char : pos_char);
+	break;
 	case DD_MM_SSPS:
 		min = (acoor - (int)acoor) * 60.0;
-		g_sprintf(scoor, "%d°%02d'%04.1f\"", (int)coor, (int)min,
-			((min - (int)min) * 60.0));
-		break;
+		g_sprintf(scoor, "%d°%02d'%04.1f\"", (int)coor, (int)min, ((min - (int)min) * 60.0));
+	break;
 	case DD_MM_SSPS_NSEW:
 		min = (acoor - (int)acoor) * 60.0;
-		g_sprintf(scoor, "%d°%02d'%04.1f\" %c", (int)acoor, (int)min,
-			((min - (int)min) * 60.0),
-			coor < 0.f ? neg_char : pos_char);
-		break;
-	default:;
+		g_sprintf(scoor, "%d°%02d'%04.1f\" %c", (int)acoor, (int)min, ((min - (int)min) * 60.0), coor < 0.f ? neg_char : pos_char);
+	break;
+	default:
+		g_return_if_reached();
+	break;
 }
 }
 
diff --git a/src/latlon.h b/src/latlon.h
index 8f5257d..11bf85c 100644
--- a/src/latlon.h
+++ b/src/latlon.h
@@ -59,13 +59,17 @@ void latlon_init(void);
 
 gint32 lon2mp_int(gdouble lon);
 gint32 lat2mp_int(gdouble lat);
+
 gdouble calculate_distance(gdouble lat1, gdouble lon1, gdouble lat2, gdouble lon2);
 gdouble calculate_ddistance(gint lat1, gint lon1, gint lat2, gint lon2);
 gulong calculate_idistance(gint lat1, gint lon1, gint lat2, gint lon2);
 gulong calculate_idistance_cmp(gint lat1, gint lon1, gint lat2, gint lon2);
+
 gdouble calculate_course_rad(gdouble lat1, gdouble lon1, gdouble lat2, gdouble lon2);
 gdouble calculate_course(gdouble lat1, gdouble lon1, gdouble lat2, gdouble lon2);
 
+gfloat angle_diff(gfloat a, gfloat b);
+
 gboolean distance_point_to_line(gdouble x, gdouble y, gdouble x1, gdouble y1, gdouble x2, gdouble y2, gdouble *d);
 
 guint32 xy2tile(guint x, guint y);