preliminary work on grid catalogs

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@2218 4e78687f-474d-0410-85f9-8d5e500ac6b2

6 files changed, 494 insertions, 94 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index d8d2718b..e44b0248 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -59,6 +59,7 @@ libproj_la_SOURCES = \
 	pj_zpoly1.c rtodms.c vector1.c pj_release.c pj_gauss.c \
 	PJ_healpix.c PJ_natearth.c \
 	\
+	pj_gc_reader.c pj_gridcatalog.c \
 	nad_cvt.c nad_init.c nad_intr.c emess.c emess.h \
 	pj_apply_gridshift.c pj_datums.c pj_datum_set.c pj_transform.c \
 	geocent.c geocent.h pj_utils.c pj_gridinfo.c pj_gridlist.c \
diff --git a/src/Makefile.in b/src/Makefile.in
index 04ef4b67..345147bf 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -102,11 +102,12 @@ am_libproj_la_OBJECTS = PJ_aeqd.lo PJ_gnom.lo PJ_laea.lo \
 	pj_open_lib.lo pj_param.lo pj_phi2.lo pj_pr_list.lo pj_qsfn.lo \
 	pj_strerrno.lo pj_tsfn.lo pj_units.lo pj_ctx.lo pj_log.lo \
 	pj_zpoly1.lo rtodms.lo vector1.lo pj_release.lo pj_gauss.lo \
-	PJ_healpix.lo PJ_natearth.lo nad_cvt.lo nad_init.lo \
-	nad_intr.lo emess.lo pj_apply_gridshift.lo pj_datums.lo \
-	pj_datum_set.lo pj_transform.lo geocent.lo pj_utils.lo \
-	pj_gridinfo.lo pj_gridlist.lo jniproj.lo pj_mutex.lo \
-	pj_initcache.lo pj_apply_vgridshift.lo
+	PJ_healpix.lo PJ_natearth.lo pj_gc_reader.lo pj_gridcatalog.lo \
+	nad_cvt.lo nad_init.lo nad_intr.lo emess.lo \
+	pj_apply_gridshift.lo pj_datums.lo pj_datum_set.lo \
+	pj_transform.lo geocent.lo pj_utils.lo pj_gridinfo.lo \
+	pj_gridlist.lo jniproj.lo pj_mutex.lo pj_initcache.lo \
+	pj_apply_vgridshift.lo
 libproj_la_OBJECTS = $(am_libproj_la_OBJECTS)
 libproj_la_LINK = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) \
 	$(LIBTOOLFLAGS) --mode=link $(CCLD) $(AM_CFLAGS) $(CFLAGS) \
@@ -165,7 +166,6 @@ CPPFLAGS = @CPPFLAGS@
 CYGPATH_W = @CYGPATH_W@
 DEFS = @DEFS@
 DEPDIR = @DEPDIR@
-DLLTOOL = @DLLTOOL@
 DSYMUTIL = @DSYMUTIL@
 DUMPBIN = @DUMPBIN@
 ECHO_C = @ECHO_C@
@@ -191,7 +191,6 @@ LN_S = @LN_S@
 LTLIBOBJS = @LTLIBOBJS@
 MAINT = @MAINT@
 MAKEINFO = @MAKEINFO@
-MANIFEST_TOOL = @MANIFEST_TOOL@
 MKDIR_P = @MKDIR_P@
 MUTEX_SETTING = @MUTEX_SETTING@
 NM = @NM@
@@ -218,7 +217,6 @@ abs_builddir = @abs_builddir@
 abs_srcdir = @abs_srcdir@
 abs_top_builddir = @abs_top_builddir@
 abs_top_srcdir = @abs_top_srcdir@
-ac_ct_AR = @ac_ct_AR@
 ac_ct_CC = @ac_ct_CC@
 ac_ct_DUMPBIN = @ac_ct_DUMPBIN@
 am__include = @am__include@
@@ -251,6 +249,7 @@ libdir = @libdir@
 libexecdir = @libexecdir@
 localedir = @localedir@
 localstatedir = @localstatedir@
+lt_ECHO = @lt_ECHO@
 mandir = @mandir@
 mkdir_p = @mkdir_p@
 oldincludedir = @oldincludedir@
@@ -318,6 +317,7 @@ libproj_la_SOURCES = \
 	pj_zpoly1.c rtodms.c vector1.c pj_release.c pj_gauss.c \
 	PJ_healpix.c PJ_natearth.c \
 	\
+	pj_gc_reader.c pj_gridcatalog.c \
 	nad_cvt.c nad_init.c nad_intr.c emess.c emess.h \
 	pj_apply_gridshift.c pj_datums.c pj_datum_set.c pj_transform.c \
 	geocent.c geocent.h pj_utils.c pj_gridinfo.c pj_gridlist.c \
@@ -601,7 +601,9 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_factors.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_fwd.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_gauss.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_gc_reader.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_geocent.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_gridcatalog.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_gridinfo.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_gridlist.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_init.Plo@am__quote@
diff --git a/src/pj_gc_reader.c b/src/pj_gc_reader.c
new file mode 100644
index 00000000..ef9479ff
--- /dev/null
+++ b/src/pj_gc_reader.c
@@ -0,0 +1,203 @@
+/******************************************************************************
+ * $Id$
+ *
+ * Project:  PROJ.4
+ * Purpose:  Code to read a grid catalog from a .cvs file.
+ * Author:   Frank Warmerdam, warmerdam@pobox.com
+ *
+ ******************************************************************************
+ * Copyright (c) 2012, Frank Warmerdam <warmerdam@pobox.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *****************************************************************************/
+
+#define PJ_LIB__
+
+#include <projects.h>
+#include <string.h>
+
+static int pj_gc_readentry( projCtx ctx, FILE *fp, PJ_GridCatalogEntry *entry );
+
+
+/************************************************************************/
+/*                         pj_gc_readcatalog()                          */
+/*                                                                      */
+/*      Read a grid catalog from a .csv file.                           */
+/************************************************************************/
+
+PJ_GridCatalog *pj_gc_readcatalog( projCtx ctx, const char *catalog_name )
+{
+    FILE *fp;
+    PJ_GridCatalog *catalog;
+    int entry_max, err;
+    
+    fp = pj_open_lib( ctx, (char *) catalog_name, "r" );
+    if (fp == NULL) 
+        return NULL;
+    
+    catalog = (PJ_GridCatalog *) calloc(1,sizeof(PJ_GridCatalog));
+    if( !catalog )
+        return NULL;
+    
+    catalog->catalog_name = strdup(catalog_name);
+    
+    entry_max = 10;
+    catalog->entries = (PJ_GridCatalogEntry *) 
+        malloc(entry_max * sizeof(PJ_GridCatalogEntry));
+    
+    while( pj_gc_readentry( ctx, fp, 
+                            catalog->entries+catalog->entry_count) == 0)
+    {
+        catalog->entry_count++;
+        
+        if( catalog->entry_count == entry_max ) 
+        {
+            entry_max = entry_max * 2;
+            catalog->entries = (PJ_GridCatalogEntry *) 
+                realloc(catalog->entries, 
+                        entry_max * sizeof(PJ_GridCatalogEntry));
+            if (catalog->entries == NULL )
+                return NULL;
+        }
+    }
+
+    return catalog;
+}
+
+
+/************************************************************************/
+/*                        pj_gc_read_csv_line()                         */
+/*                                                                      */
+/*      Simple csv line splitter with fixed maximum line size and       */
+/*      token count.                                                    */
+/************************************************************************/
+
+static int pj_gc_read_csv_line( projCtx ctx, FILE *fp, 
+                                char **tokens, int max_tokens ) 
+{
+    char line[302];
+   
+    while( fgets(line, sizeof(line)-1, fp) != NULL )
+    {
+        char *next = line;
+        int token_count = 0;
+        
+        while( isspace(*next) ) 
+            next++;
+        
+        /* skip blank and comment lines */
+        if( next[0] == '#' || next[0] == '\0' )
+            continue;
+        
+        while( token_count < max_tokens && next != '\0' ) 
+        {
+            const char *start = next;
+            
+            while( *next != '\0' && *next != ',' ) 
+                next++;
+            
+            if( *next == ',' )
+            {
+                *next = '\0';
+                next++;
+            }
+            
+            tokens[token_count++] = strdup(start);
+        }
+
+        return token_count;
+    }
+    
+    return 0; 
+}
+
+/************************************************************************/
+/*                          pj_gc_parsedate()                           */
+/*                                                                      */
+/*      Parse a date into a floating point year value.  Acceptable      */
+/*      values are "yyyy.fraction" and "yyyy-mm-dd".  Anything else     */
+/*      returns 0.0.                                                    */
+/************************************************************************/
+
+double pj_gc_parsedate( projCtx ctx, const char *date_string )
+{
+    if( strlen(date_string) == 10 
+        && date_string[4] == '-' && date_string[7] == '-' ) 
+    {
+        int year = atoi(date_string);
+        int month = atoi(date_string+5);
+        int day = atoi(date_string+8);
+
+        /* simplified calculation so we don't need to know all about months */
+        return year + ((month-1) * 31 + (day-1)) / 372.0;
+    }
+    else 
+    {
+        return atof(date_string);
+    }
+}
+
+
+/************************************************************************/
+/*                          pj_gc_readentry()                           */
+/*                                                                      */
+/*      Read one catalog entry from the file                            */
+/*                                                                      */
+/*      Format:                                                         */
+/*        gridname,ll_long,ll_lat,ur_long,ur_lat,priority,date          */
+/************************************************************************/
+
+static int pj_gc_readentry( projCtx ctx, FILE *fp, PJ_GridCatalogEntry *entry ) 
+{
+#define MAX_TOKENS 30
+    char *tokens[MAX_TOKENS];
+    int token_count, i;
+    int error = 0;
+
+    memset( entry, 0, sizeof(PJ_GridCatalogEntry) );
+    
+    token_count = pj_gc_read_csv_line( ctx, fp, tokens, MAX_TOKENS );
+    if( token_count < 5 )
+    {
+        error = 1; /* TODO: need real error codes */
+        pj_log( ctx, PJ_LOG_ERROR, "Short line in grid catalog." );
+    }
+    else
+    {
+        memset( entry, 0, sizeof(PJ_GridCatalogEntry));
+        
+        entry->definition = strdup( tokens[0] );
+        entry->region.ll_long = dmstor_ctx( ctx, tokens[1], NULL );
+        entry->region.ll_lat = dmstor_ctx( ctx, tokens[2], NULL );
+        entry->region.ur_long = dmstor_ctx( ctx, tokens[3], NULL );
+        entry->region.ur_lat = dmstor_ctx( ctx, tokens[4], NULL );
+        if( token_count > 5 )
+            entry->priority = atoi( tokens[5] ); /* defaults to zero */
+        if( token_count > 6 )
+            entry->date = pj_gc_parsedate( ctx, tokens[6] );
+    }
+
+    for( i = 0; i < token_count; i++ )
+        free( tokens[i] );
+
+    return error;
+}
+
+
+
diff --git a/src/pj_gridcatalog.c b/src/pj_gridcatalog.c
new file mode 100644
index 00000000..48808368
--- /dev/null
+++ b/src/pj_gridcatalog.c
@@ -0,0 +1,219 @@
+/******************************************************************************
+ * $Id$
+ *
+ * Project:  PROJ.4
+ * Purpose:  Code in support of grid catalogs
+ * Author:   Frank Warmerdam, warmerdam@pobox.com
+ *
+ ******************************************************************************
+ * Copyright (c) 2012, Frank Warmerdam <warmerdam@pobox.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *****************************************************************************/
+
+#define PJ_LIB__
+
+#include <projects.h>
+#include <string.h>
+
+static PJ_GridCatalog *grid_catalog_list = NULL;
+
+/************************************************************************/
+/*                          pj_gc_unloadall()                           */
+/*                                                                      */
+/*      Deallocate all the grid catalogs (but not the referenced        */
+/*      grids).                                                         */
+/************************************************************************/
+
+void pj_gc_unloadall( projCtx ctx )
+
+{
+    while( grid_catalog_list != NULL )
+    {
+        int i;
+        PJ_GridCatalog *catalog = grid_catalog_list;
+        grid_catalog_list = grid_catalog_list->next;
+
+        for( i = 0; i < catalog->entry_count; i++ )
+        {
+            /* we don't own gridinfo - do not free here */
+            free( catalog->entries[i].definition );
+        }
+        free( catalog->entries );
+        free( catalog );
+    }
+}
+
+/************************************************************************/
+/*                         pj_gc_findcatalog()                          */
+/************************************************************************/
+
+PJ_GridCatalog *pj_gc_findcatalog( projCtx ctx, const char *name )
+
+{
+    PJ_GridCatalog *catalog;
+
+    pj_acquire_lock();
+
+    for( catalog=grid_catalog_list; catalog != NULL; catalog = catalog->next ) 
+    {
+        if( strcmp(catalog->catalog_name, name) == 0 )
+        {
+            pj_release_lock();
+            return catalog;
+        }
+    }
+
+    pj_release_lock();
+
+    catalog = pj_gc_readcatalog( ctx, name );
+    if( catalog == NULL )
+        return NULL;
+
+    pj_acquire_lock();
+    catalog->next = grid_catalog_list;
+    grid_catalog_list = catalog;
+    pj_release_lock();
+
+    return catalog;
+}
+
+/************************************************************************/
+/*                       pj_gc_apply_gridshift()                        */
+/************************************************************************/
+
+int pj_gc_apply_gridshift( PJ *defn, int inverse, 
+                           long point_count, int point_offset, 
+                           double *x, double *y, double *z )
+
+{
+    int i;
+
+    if( defn->catalog == NULL ) 
+    {
+        defn->catalog = pj_gc_findcatalog( defn->ctx, defn->catalog_name );
+        if( defn->catalog == NULL )
+            return defn->ctx->last_errno;
+    }
+
+    ctx->last_errno = 0;
+
+    for( i = 0; i < point_count; i++ )
+    {
+        long io = i * point_offset;
+        LP   input, output;
+        int  itable;
+
+        input.phi = y[io];
+        input.lam = x[io];
+        output.phi = HUGE_VAL;
+        output.lam = HUGE_VAL;
+
+        /* make sure we have appropriate "before" shift file available */
+        if( defn->last_before_grid == NULL
+            || input.lam < defn->last_before_region.ll_long
+            || input.lam > defn->last_before_region.ur_long
+            || input.phi < defn->last_before_region.ll_lat
+            || input.phi > defn->last_before_region.ll_lat ) {
+            defn->last_before_grid = pj_gc_findgrid(
+                defn->ctx, defn->catalog, 0, ll, 0.0, 
+                &(defn->last_before_region), NULL);
+        }
+
+        PJ_GRIDINFO *gi = defn->last_before_grid;
+        struct CTABLE *ct = gi->ct;
+        double epsilon = (fabs(ct->del.phi)+fabs(ct->del.lam))/10000.0;
+        
+        /* If we have child nodes, check to see if any of them apply. */
+        if( gi->child != NULL )
+        {
+            PJ_GRIDINFO *child;
+            
+            for( child = gi->child; child != NULL; child = child->next )
+            {
+                struct CTABLE *ct1 = child->ct;
+                double epsilon = 
+                    (fabs(ct1->del.phi)+fabs(ct1->del.lam))/10000.0;
+                
+                if( ct1->ll.phi - epsilon > input.phi 
+                    || ct1->ll.lam - epsilon > input.lam
+                    || (ct1->ll.phi+(ct1->lim.phi-1)*ct1->del.phi + epsilon 
+                        < input.phi)
+                    || (ct1->ll.lam+(ct1->lim.lam-1)*ct1->del.lam + epsilon 
+                        < input.lam) )
+                    continue;
+                
+                break;
+            }
+
+            /* we found a more refined child node to use */
+            if( child != NULL )
+            {
+                gi = child;
+                ct = child->ct;
+            }
+        }
+
+        /* load the grid shift info if we don't have it. */
+        if( ct->cvs == NULL && !pj_gridinfo_load( ctx, gi ) )
+        {
+            pj_ctx_set_errno( ctx, -38 );
+            return -38;
+        }
+            
+        output = nad_cvt( input, inverse, ct );
+        if( output.lam != HUGE_VAL )
+        {
+            if( debug_count++ < 20 )
+                pj_log( ctx, PJ_LOG_DEBUG_MINOR,
+                        "pj_apply_gridshift(): used %s", ct->id );
+            break;
+        }
+
+
+        if( output.lam == HUGE_VAL )
+        {
+            if( ctx->debug_level >= PJ_LOG_DEBUG_MAJOR )
+            {
+                pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
+                        "pj_apply_gridshift(): failed to find a grid shift table for\n"
+                        "                      location (%.7fdW,%.7fdN)",
+                        x[io] * RAD_TO_DEG, 
+                        y[io] * RAD_TO_DEG );
+                for( itable = 0; itable < grid_count; itable++ )
+                {
+                    PJ_GRIDINFO *gi = tables[itable];
+                    if( itable == 0 )
+                        pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
+                                "   tried: %s", gi->gridname );
+                    else
+                        pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
+                                ",%s", gi->gridname );
+                }
+            }
+        }
+        else
+        {
+            y[io] = output.phi;
+            x[io] = output.lam;
+        }
+    }
+
+    return 0;
+}
diff --git a/src/proj_newgrid.h b/src/proj_newgrid.h
deleted file mode 100644
index c8efb76c..00000000
--- a/src/proj_newgrid.h
+++ /dev/null
@@ -1,85 +0,0 @@
-/******************************************************************************
- * $Id$
- *
- * Project:  PROJ.4
- * Purpose:  Definitions related to new datum shift grid (date aware) API.
- * Author:   Frank Warmerdam, <warmerdam@pobox.com>
- *
- ******************************************************************************
- * Copyright (c) 2012, Frank Warmerdam <warmerdam@pobox.com>
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included
- * in all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
- * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
- * DEALINGS IN THE SOFTWARE.
- *****************************************************************************/
-
-#ifndef PROJ_NEWGRID_H
-#define PROJ_NEWGRID_H
-
-typedef struct {
-    LP ll;      /* lower left corner coordinates */
-    LP del;     /* size of cells */
-    ILP lim;    /* width/height of grid (value count) */
-
-    double date; /* year.fraction */
-
-    const char *definition; /* usually the gridname */
-
-    PJ_GRIDINFO  *gridinfo;
-    
-    int available; /* 0=unknown, 1=true, -1=false */
-} PJ_GridCatalogEntry;
-
-typedef struct {
-    char *catalog_name;
-    
-    LP last_grid_ll; /* maximum extent of catalog data */
-    LP last_grid_ur;
-
-    int entry_count;
-    PJ_GridCatalogEntry *entries;
-} PJ_GridCatalog;
-
-typedef struct {
-
-    PJ_GridCatalog *catalog;
-
-    double   datum_date;
-    
-    PJ_NGRIDINFO *last_before_grid;
-    PJ_NGRIDINFO *last_after_grid;
- 
-    LP last_grid_ll; /* region for which the last grid set is optimal */
-    LP last_grid_ur;
-
-} PJ_GridEvalInfo;
-
-PJ_GridCatalog *pj_gc_findcatalog( const char * );
-void pj_gc_unloadall();
-
-PJ_GRIDINFO *pj_gc_findgrid( PJ_GridCatalog *catalog, int after, 
-                             LP location, double date,
-                             LP *optimal_ll, LP *optimal_ur,
-                             double *grid_date );
-
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* ndef PROJ_NEWGRID_H */
-
diff --git a/src/projects.h b/src/projects.h
index e282ecb5..a15ed596 100644
--- a/src/projects.h
+++ b/src/projects.h
@@ -144,6 +144,7 @@ typedef struct {
 #define PJD_ERR_GEOCENTRIC          -45
 #define PJD_ERR_AXIS                -47
 #define PJD_ERR_GRID_AREA           -48
+#define PJD_ERR_CATALOG             -49
 
 #define USE_PROJUV 
 
@@ -190,6 +191,13 @@ struct PJ_PRIME_MERIDIANS {
     char    *defn;   /* offset from greenwich in DMS format. */
 };
 
+typedef struct {
+    double ll_long;      /* lower left corner coordinates (radians) */
+    double ll_lat;
+    double ur_long;      /* upper right corner coordinates (radians) */
+    double ur_lat; 
+} PJ_Region;
+
 struct DERIVS {
     double x_l, x_p; /* derivatives of x for lambda-phi */
     double y_l, y_p; /* derivatives of y for lambda-phi */
@@ -256,7 +264,19 @@ typedef struct PJconsts {
         double  long_wrap_center; /* 0.0 for -180 to 180, actually in radians*/
         int     is_long_wrap_set;
         char    axis[4];
-        
+
+        /* New Datum Shift Grid Catalogs */
+        char   *catalog_name;
+        struct _PJ_GridCatalog *catalog;
+    
+        double   datum_date;
+    
+        struct _pj_gi *last_before_grid;
+        PJ_Region     last_before_region;
+
+        struct _pj_gi *last_after_grid;
+        PJ_Region     last_after_region;
+
 #ifdef PROJ_PARMS__
 PROJ_PARMS__
 #endif /* end of optional extensions */
@@ -347,6 +367,28 @@ typedef struct _pj_gi {
     struct _pj_gi *child;
 } PJ_GRIDINFO;
 
+typedef struct _PJ_GridCatalog {
+    PJ_Region region;
+    int  priority; /* higher used before lower */
+    double date; /* year.fraction */
+    char *definition; /* usually the gridname */
+
+    PJ_GRIDINFO  *gridinfo;
+    int available; /* 0=unknown, 1=true, -1=false */
+} PJ_GridCatalogEntry;
+
+typedef struct _pj_gc {
+    char *catalog_name;
+
+    PJ_Region region; /* maximum extent of catalog data */
+
+    int entry_count;
+    PJ_GridCatalogEntry *entries;
+
+    struct _pj_gc *next;
+} PJ_GridCatalog;
+
+
 /* procedure prototypes */
 double dmstor(const char *, char **);
 double dmstor_ctx(projCtx ctx, const char *, char **);
@@ -437,6 +479,24 @@ PJ_GRIDINFO *pj_gridinfo_init( projCtx, const char * );
 int pj_gridinfo_load( projCtx, PJ_GRIDINFO * );
 void pj_gridinfo_free( projCtx, PJ_GRIDINFO * );
 
+PJ_GridCatalog *pj_gc_findcatalog( projCtx, const char * );
+PJ_GridCatalog *pj_gc_readcatalog( projCtx, const char * );
+void pj_gc_unloadall( projCtx );
+int pj_gc_apply_gridshift( PJ *defn, int inverse, 
+                           long point_count, int point_offset,
+                           double *x, double *y, double *z );
+int pj_gc_apply_gridshift( PJ *defn, int inverse, 
+                           long point_count, int point_offset,
+                           double *x, double *y, double *z );
+
+PJ_GRIDINFO *pj_gc_findgrid( projCtx ctx, 
+                             PJ_GridCatalog *catalog, int after, 
+                             LP location, double date,
+                             PJ_Region *optional_region,
+                             double *grid_date );
+
+double pj_gc_parsedate( projCtx, const char * );
+
 void *proj_mdist_ini(double);
 double proj_mdist(double, double, double, const void *);
 double proj_inv_mdist(projCtx ctx, double, const void *);