From: Kaj-Michael Lang <milang@onion.tal.org>
Date: Mon, 16 Jul 2007 11:02:52 +0000 (+0300)
Subject: Start to move lat/lon conversion functions/helpers here
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=29935bc5ab0a66c55d566eb9262d697079452c51;p=mapper

Start to move lat/lon conversion functions/helpers here
---

diff --git a/src/latlon.c b/src/latlon.c
new file mode 100644
index 0000000..472a983
--- /dev/null
+++ b/src/latlon.c
@@ -0,0 +1,26 @@
+#define _GNU_SOURCE
+
+#include <math.h>
+#include <glib.h>
+
+#include "osm.h"
+
+/* Int ranges for integerized lat/lon */
+#define LATLON_MAX 2147483646
+#define LATLON_MIN -2147483646
+
+/* Convert latitude to integerized+mercator projected value */
+gint32
+lat2mp_int(gdouble lat)
+{
+return lat > 85.051128779 ? LATLON_MAX : lat < -85.051128779 ? LATLON_MIN :
+	lrint(log(tan(M_PI_4l+lat*M_PIl/360))/M_PIl*LATLON_MAX);
+}
+
+/* Convert longitude to integerized+mercator projected value */
+gint32
+lon2mp_int(gdouble lon)
+{
+return lrint(lon/180*LATLON_MAX);
+}
+
diff --git a/src/latlon.h b/src/latlon.h
new file mode 100644
index 0000000..774756d
--- /dev/null
+++ b/src/latlon.h
@@ -0,0 +1,5 @@
+#include <glib.h>
+
+gint32 lon2mp_int(gdouble lon);
+gint32 lat2mp_int(gdouble lat);
+