[Gislite-admins] SF.net SVN: gislite: [13] trunk/sqlfunc.c

[<cto...@us...>]

Revision: 13
          http://gislite.svn.sourceforge.net/gislite/?rev=13&view=rev
Author:   ctomasin
Date:     2007-09-05 12:35:51 -0700 (Wed, 05 Sep 2007)

Log Message:
-----------
Sql function Distance() added

Modified Paths:
--------------
    trunk/sqlfunc.c

Modified: trunk/sqlfunc.c
===================================================================
--- trunk/sqlfunc.c	2007-09-04 18:22:20 UTC (rev 12)
+++ trunk/sqlfunc.c	2007-09-05 19:35:51 UTC (rev 13)
@@ -219,6 +219,32 @@
 	}
 }
 
+/**
+ * SQL function Distance(geomA,geomB)
+ * Returns the distance between two geometries.
+ * Ex:
+ * sqlite> SELECT Distance(BLOB_POINT,BLOB_POINT);
+ * sqlite> 1.2000
+ *
+ * @param geomA WKBGeometry structure
+ * @param geomB WKBGeometry structure
+ *
+ * @return double representing the distance
+ */
+static void Distance(
+	sqlite3_context *context,
+	int argc,
+	sqlite3_value **argv
+){
+	WKBGeometry *pGeomA, *pGeomB;
+	
+	if( sqlite3_value_type(argv[0]) != SQLITE_BLOB || sqlite3_value_type(argv[1]) != SQLITE_BLOB )
+		sqlite3_result_error(context,messages[4],-1); // verify message text
+	
+	pGeomA = GeomFromBinary((unsigned char*)sqlite3_value_blob(argv[0]));		
+	pGeomB = GeomFromBinary((unsigned char*)sqlite3_value_blob(argv[1]));
+	sqlite3_result_double(context,GeomDistance(pGeomA,pGeomB));
+}
 
 /**
  * SQL function StartPoint(g)
@@ -314,6 +340,7 @@
 	//Geometry functions
 	sqlite3_create_function(db, "AsText", 1, SQLITE_ANY, 0, AsText, 0, 0);
 	sqlite3_create_function(db, "AsBinary", 1, SQLITE_ANY, 0, AsBinary, 0, 0);
+	sqlite3_create_function(db, "Distance", 2, SQLITE_ANY, 0, Distance, 0, 0);
 	//sqlite3_create_function(db, "SRID", 1, SQLITE_ANY, 0, SRID, 0, 0);
 	//sqlite3_create_function(db, "Dimension", 1, SQLITE_ANY, 0, Dimension, 0, 0);
 	


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