Extend the PROJ.4 search path to include $sharedir/contrib/postgis/nad when looking...

git-svn-id: http://svn.osgeo.org/postgis/trunk@2718 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/lwgeom/lwgeom_transform.c b/lwgeom/lwgeom_transform.c
index c1d435df34581b127f88cecced2aeea4d6c388be..4b0deead2faa34635f060d780bf645fa52c8f911 100644 (file)
--- a/lwgeom/lwgeom_transform.c
+++ b/lwgeom/lwgeom_transform.c
@@ -18,10 +18,12 @@
 
 #include "postgres.h"
 #include "fmgr.h"
+#include "miscadmin.h"
 
 #include "liblwgeom.h"
 #include "lwgeom_pg.h"
 
+
 Datum transform(PG_FUNCTION_ARGS);
 Datum transform_geom(PG_FUNCTION_ARGS);
 Datum postgis_proj_version(PG_FUNCTION_ARGS);
@@ -141,6 +143,10 @@ PJ *GetProjectionFromPROJ4SRSCache(PROJ4PortalCache *PROJ4Cache, int srid);
 void AddToPROJ4SRSCache(PROJ4PortalCache *PROJ4Cache, int srid, int other_srid);
 void DeleteFromPROJ4SRSCache(PROJ4PortalCache *PROJ4Cache, int srid);
 
+/* Search path for PROJ.4 library */
+static bool IsPROJ4LibPathSet = false;
+void SetPROJ4LibPath();
+
 /* Memory context cache functions */
 static void PROJ4SRSCacheInit(MemoryContext context);
 static void PROJ4SRSCacheDelete(MemoryContext context);
@@ -562,6 +568,38 @@ void DeleteFromPROJ4SRSCache(PROJ4PortalCache *PROJ4Cache, int srid)
 }
 
 
+/*
+ * Specify an alternate directory for the PROJ.4 grid files
+ * (this should augment the PROJ.4 compile-time path)
+ *
+ * It's main purpose is to allow Win32 PROJ.4 installations
+ * to find a set grid shift files, although other platforms
+ * may find this useful too.
+ */
+void SetPROJ4LibPath()
+{
+       char *path;
+       const char **proj_lib_path;
+
+       /* 
+        * Get the sharepath and append /contrib/postgis/nad to form a suitable
+        * directory in which to store the grid shift files
+        */     
+       proj_lib_path = palloc(sizeof(char *));
+       path = palloc(MAXPGPATH);
+       *proj_lib_path = path;
+
+       get_share_path(my_exec_path, path);
+       strncat(path, "/contrib/postgis/nad", MAXPGPATH - strlen(path) - 1);
+
+       /* Set the search path for PROJ.4 */
+       pj_set_searchpath(1, proj_lib_path);
+
+       /* Ensure we only do this once... */
+       IsPROJ4LibPathSet = true;
+}
+
+
 /*
  * This is *exactly* the same as PROJ.4's pj_transform(),
  * but it doesn't do the datum shift.
@@ -771,6 +809,8 @@ lwgeom_transform_recursive(uchar *geom, PJ *inpj, PJ *outpj)
 }
 
 
+
+
 /*
  * transform( GEOMETRY, INT (output srid) )
  * tmpPts - if there is a nadgrid error (-38), we re-try the transform
@@ -805,6 +845,10 @@ Datum transform(PG_FUNCTION_ARGS)
                PG_RETURN_NULL();
        }
 
+       /* Set the search path if we haven't already */
+       if (!IsPROJ4LibPathSet)
+               SetPROJ4LibPath();
+
        /*
         * If input SRID and output SRID are equal, return geometry
         * without transform it
@@ -918,6 +962,7 @@ Datum transform_geom(PG_FUNCTION_ARGS)
        uchar *srl;
        int* pj_errno_ref;
 
+
        result_srid = PG_GETARG_INT32(3);
        if (result_srid == -1)
        {
@@ -933,6 +978,10 @@ Datum transform_geom(PG_FUNCTION_ARGS)
                PG_RETURN_NULL();
        }
 
+       /* Set the search path if we haven't already */
+       if (!IsPROJ4LibPathSet)
+               SetPROJ4LibPath();
+
        input_proj4_text  = (PG_GETARG_TEXT_P(1));
        output_proj4_text = (PG_GETARG_TEXT_P(2));