Add Blue Marble Next Gen plugin and tile rendering code

[grits] / src / gis-world.c

diff --git a/src/gis-world.c b/src/gis-world.c
index b8611aba2030d9957f6026d41d809277bcb42a72..c4d74b836e302cfdf32cd42773b034eb1fbe6240 100644 (file)
--- a/src/gis-world.c
+++ b/src/gis-world.c
@@ -1,16 +1,16 @@
 /*
  * Copyright (C) 2009 Andy Spencer <spenceal@rose-hulman.edu>
- * 
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
  * (at your option) any later version.
- * 
+ *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
@@ -151,6 +151,13 @@ void xyz2lle(gdouble x, gdouble y, gdouble z,
        *elev = rad2elev(rad);
 }
 
+void xyz2ll(gdouble x, gdouble y, gdouble z,
+               gdouble *lat, gdouble *lon)
+{
+       gdouble rad = sqrt(x*x + y*y + z*z);
+       *lat = incl2lat(acos(y / rad));
+       *lon = azim2lon(atan2(x,z));
+}
 
 gdouble ll2m(gdouble lon_dist, gdouble lat)
 {