From 81d56dfdc01ee61a650ec80539262faacb4cc1c7 Mon Sep 17 00:00:00 2001
From: Arkshine <hv.contact@gmail.com>
Date: Thu, 31 Jul 2014 11:33:58 +0200
Subject: [PATCH] Geoip: Add geoip_distance() native.

---
 dlls/geoip/geoip_amxx.cpp | 14 ++++++++++++++
 plugins/include/geoip.inc | 18 +++++++++++++++++-
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/dlls/geoip/geoip_amxx.cpp b/dlls/geoip/geoip_amxx.cpp
index e335dd59..0ae6ba27 100755
--- a/dlls/geoip/geoip_amxx.cpp
+++ b/dlls/geoip/geoip_amxx.cpp
@@ -279,6 +279,19 @@ static cell AMX_NATIVE_CALL amx_geoip_longitude(AMX *amx, cell *params)
 	return amx_ftoc(longitude);
 }
 
+// native Float:geoip_distance(Float:lat1, Float:lon1, Float:lat2, Float:lon2, system = SYSTEM_METRIC);
+static cell AMX_NATIVE_CALL amx_geoip_distance(AMX *amx, cell *params)
+{
+	float earthRadius = params[5] ? 3958.0 : 6370.997; // miles / km
+
+	float lat1 = amx_ctof(params[1]) * (M_PI / 180);
+	float lon1 = amx_ctof(params[2]) * (M_PI / 180);
+	float lat2 = amx_ctof(params[3]) * (M_PI / 180);
+	float lon2 = amx_ctof(params[4]) * (M_PI / 180);
+
+	return amx_ftoc(earthRadius * acos(sin(lat1) * sin(lat2) + cos(lat1) * cos(lat2) * cos(lon2 - lon1)));
+}
+
 
 void OnAmxxAttach()
 {
@@ -352,6 +365,7 @@ AMX_NATIVE_INFO geoip_natives[] =
 	{ "geoip_timezone" , amx_geoip_timezone  },
 	{ "geoip_latitude" , amx_geoip_latitude  },
 	{ "geoip_longitude", amx_geoip_longitude },
+	{ "geoip_distance" , amx_geoip_distance  },
 
 	{ NULL, NULL },
 };
diff --git a/plugins/include/geoip.inc b/plugins/include/geoip.inc
index eec43d56..ef1295e5 100755
--- a/plugins/include/geoip.inc
+++ b/plugins/include/geoip.inc
@@ -150,4 +150,20 @@ native Float:geoip_latitude(const ip[]);
  *
  * @return			The result of the geoip look up, 0 if longitude is not found. 
  */ 
-native Float:geoip_longitude(const ip[]);
\ No newline at end of file
+native Float:geoip_longitude(const ip[]);
+
+/**
+ * Calculate the distance between geographical coordinates, latitude and longitude.
+ *
+ * @param lat1		The first IP latitude.
+ * @param lon1		The first IP longitude.
+ * @param lat2		The second IP latitude.
+ * @param lon2		The second IP longitude.
+ * @param system    The system of measurement, 0 = Metric(kilometers) or 1 = English(miles).  
+ *
+ * @return			The distance as result in specified system of measurement.
+ */
+#define SYSTEM_METRIC   0 // kilometers
+#define SYSTEM_IMPERIAL 1 // statute miles
+
+native Float:geoip_distance(Float:lat1, Float:lon1, Float:lat2, Float:lon2, system = SYSTEM_METRIC);
\ No newline at end of file