Added experimental +lon_wrap argument to set a "center point" for

longitude wrapping of longitude values coming out of pj_transform().


git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@1353 4e78687f-474d-0410-85f9-8d5e500ac6b2

3 files changed, 35 insertions, 0 deletions

diff --git a/src/pj_init.c b/src/pj_init.c
index 94383e85..4b120080 100644
--- a/src/pj_init.c
+++ b/src/pj_init.c
@@ -30,6 +30,10 @@
  ******************************************************************************
  *
  * $Log$
+ * Revision 1.18  2006/10/12 21:04:39  fwarmerdam
+ * Added experimental +lon_wrap argument to set a "center point" for
+ * longitude wrapping of longitude values coming out of pj_transform().
+ *
  * Revision 1.17  2006/09/22 23:06:24  fwarmerdam
  * remote static start variable in pj_init (bug 1283)
  *
@@ -270,6 +274,7 @@ pj_init(int argc, char **argv) {
 	PIN->params = start;
         PIN->is_latlong = 0;
         PIN->is_geocent = 0;
+        PIN->long_wrap_center = 0.0;
 
         /* set datum parameters */
         if (pj_datum_set(start, PIN)) goto bum_call;
@@ -300,6 +305,9 @@ pj_init(int argc, char **argv) {
 	/* over-ranging flag */
 	PIN->over = pj_param(start, "bover").i;
 
+	/* longitude center for wrapping */
+	PIN->long_wrap_center = pj_param(start, "rlon_wrap").f;
+
 	/* central meridian */
 	PIN->lam0=pj_param(start, "rlon_0").f;
 
diff --git a/src/pj_transform.c b/src/pj_transform.c
index cde6ffd7..c3a437e5 100644
--- a/src/pj_transform.c
+++ b/src/pj_transform.c
@@ -30,6 +30,10 @@
  ******************************************************************************
  *
  * $Log$
+ * Revision 1.20  2006/10/12 21:04:39  fwarmerdam
+ * Added experimental +lon_wrap argument to set a "center point" for
+ * longitude wrapping of longitude values coming out of pj_transform().
+ *
  * Revision 1.19  2006/05/10 19:23:47  fwarmerdam
  * Don't apply to_meter in pj_transform() if the value is HUGE_VAL.
  *
@@ -336,6 +340,24 @@ int pj_transform( PJ *srcdefn, PJ *dstdefn, long point_count, int point_offset,
         }
     }
 
+/* -------------------------------------------------------------------- */
+/*      If a wrapping center other than 0 is provided, rewrap around    */
+/*      the suggested center (for latlong coordinate systems only).     */
+/* -------------------------------------------------------------------- */
+    else if( dstdefn->is_latlong && dstdefn->long_wrap_center != 0 )
+    {
+        for( i = 0; i < point_count; i++ )
+        {
+            if( x[point_offset*i] == HUGE_VAL )
+                continue;
+
+            while( x[point_offset*i] < dstdefn->long_wrap_center - HALFPI )
+                x[point_offset*i] += PI;
+            while( x[point_offset*i] > dstdefn->long_wrap_center + HALFPI )
+                x[point_offset*i] -= PI;
+        }
+    }
+
     return 0;
 }
 
diff --git a/src/projects.h b/src/projects.h
index 042fcd36..fdf0a48f 100644
--- a/src/projects.h
+++ b/src/projects.h
@@ -28,6 +28,10 @@
  ******************************************************************************
  *
  * $Log$
+ * Revision 1.23  2006/10/12 21:04:39  fwarmerdam
+ * Added experimental +lon_wrap argument to set a "center point" for
+ * longitude wrapping of longitude values coming out of pj_transform().
+ *
  * Revision 1.22  2006/03/30 14:35:09  fwarmerdam
  * bug 1145: avoid warnings on VC8.
  *
@@ -271,6 +275,7 @@ typedef struct PJconsts {
         int     datum_type; /* PJD_UNKNOWN/3PARAM/7PARAM/GRIDSHIFT/WGS84 */
         double  datum_params[7];
         double  from_greenwich; /* prime meridian offset (in radians) */
+        double  long_wrap_center; /* 0.0 for -180 to 180, actually in radians*/
         
 #ifdef PROJ_PARMS__
 PROJ_PARMS__