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git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@1090 4e78687f-474d-0410-85f9-8d5e500ac6b2

1 files changed, 241 insertions, 0 deletions

diff --git a/src/pj_gridlist.c b/src/pj_gridlist.c
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+++ b/src/pj_gridlist.c
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+/******************************************************************************
+ * $Id$
+ *
+ * Project:  PROJ.4
+ * Purpose:  Code to manage the list of currently loaded (cached) PJ_GRIDINFOs
+ *           See pj_gridinfo.c for details of loading individual grids.
+ * Author:   Frank Warmerdam, warmerdam@pobox.com
+ *
+ ******************************************************************************
+ * Copyright (c) 2000, 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.
+ ******************************************************************************
+ *
+ * $Log$
+ * Revision 1.1  2003/03/15 06:01:18  warmerda
+ * New
+ *
+ */
+
+#define PJ_LIB__
+
+#include <projects.h>
+#include <string.h>
+#include <math.h>
+#include <assert.h>
+
+static PJ_GRIDINFO *grid_list = NULL;
+
+/* used only by pj_load_nadgrids() and pj_deallocate_grids() */
+
+static int           last_nadgrids_max = 0;
+static int           last_nadgrids_count = 0;
+static PJ_GRIDINFO **last_nadgrids_list = NULL;
+static char         *last_nadgrids = NULL;
+
+/************************************************************************/
+/*                        pj_deallocate_grids()                         */
+/*                                                                      */
+/*      Deallocate all loaded grids.                                    */
+/************************************************************************/
+
+void pj_deallocate_grids()
+
+{
+    while( grid_list != NULL )
+    {
+        PJ_GRIDINFO *item = grid_list;
+        grid_list = grid_list->next;
+        item->next = NULL;
+
+        pj_gridinfo_free( item );
+    }
+
+    if( last_nadgrids != NULL )
+    {
+        pj_dalloc( last_nadgrids );
+        last_nadgrids = NULL;
+
+        pj_dalloc( last_nadgrids_list );
+        last_nadgrids_list = NULL;
+
+        last_nadgrids_count = 0;
+        last_nadgrids_max = 0;
+    }
+}
+
+/************************************************************************/
+/*                       pj_gridlist_merge_grid()                       */
+/*                                                                      */
+/*      Find/load the named gridfile and merge it into the              */
+/*      last_nadgrids_list.                                             */
+/************************************************************************/
+
+static int pj_gridlist_merge_gridfile( const char *gridname )
+
+{
+    int i, got_match=0;
+    PJ_GRIDINFO *this_grid, *tail = NULL;
+
+/* -------------------------------------------------------------------- */
+/*      Try to find in the existing list of loaded grids.  Add all      */
+/*      matching grids as with NTv2 we can get many grids from one      */
+/*      file (one shared gridname).                                     */
+/* -------------------------------------------------------------------- */
+    for( this_grid = grid_list; this_grid != NULL; this_grid = this_grid->next)
+    {
+        if( strcmp(this_grid->gridname,gridname) == 0 )
+        {
+            got_match = 1;
+
+            /* dont add to the list if it is invalid. */
+            if( this_grid->ct == NULL )
+                return 0;
+
+            /* do we need to grow the list? */
+            if( last_nadgrids_count >= last_nadgrids_max - 2 )
+            {
+                PJ_GRIDINFO **new_list;
+                int new_max = last_nadgrids_max + 20;
+
+                new_list = (PJ_GRIDINFO **) pj_malloc(sizeof(void*) * new_max);
+                if( last_nadgrids_list != NULL )
+                {
+                    memcpy( new_list, last_nadgrids_list, 
+                            sizeof(void*) * last_nadgrids_max );
+                    pj_dalloc( last_nadgrids_list );
+                }
+
+                last_nadgrids_list = new_list;
+                last_nadgrids_max = new_max;
+            }
+
+            /* add to the list */
+            last_nadgrids_list[last_nadgrids_count++] = this_grid;
+            last_nadgrids_list[last_nadgrids_count] = NULL;
+        }
+
+        tail = this_grid;
+    }
+
+    if( got_match )
+        return 1;
+
+/* -------------------------------------------------------------------- */
+/*      Try to load the named grid.                                     */
+/* -------------------------------------------------------------------- */
+    this_grid = pj_gridinfo_init( gridname );
+
+    if( this_grid == NULL )
+    {
+        /* we should get at least a stub grid with a missing "ct" member */
+        assert( FALSE );
+        return 0;
+    }
+    
+    if( tail != NULL )
+        tail->next = this_grid;
+    else
+        grid_list = this_grid;
+
+/* -------------------------------------------------------------------- */
+/*      Recurse to add the grid now that it is loaded.                  */
+/* -------------------------------------------------------------------- */
+    return pj_gridlist_merge_gridfile( gridname );
+}
+
+/************************************************************************/
+/*                     pj_gridlist_from_nadgrids()                      */
+/*                                                                      */
+/*      This functions loads the list of grids corresponding to a       */
+/*      particular nadgrids string into a list, and returns it.  The    */
+/*      list is kept around till a request is made with a different     */
+/*      string in order to cut down on the string parsing cost, and     */
+/*      the cost of building the list of tables each time.              */
+/************************************************************************/
+
+PJ_GRIDINFO **pj_gridlist_from_nadgrids( const char *nadgrids, int *grid_count)
+
+{
+    const char *s;
+
+    pj_errno = 0;
+    *grid_count = 0;
+
+    if( last_nadgrids != NULL 
+        && strcmp(nadgrids,last_nadgrids) == 0 )
+    {
+        *grid_count = last_nadgrids_count;
+        return last_nadgrids_list;
+    }
+
+/* -------------------------------------------------------------------- */
+/*      Free old one, if any, and make space for new list.              */
+/* -------------------------------------------------------------------- */
+    if( last_nadgrids != NULL )
+    {
+        pj_dalloc(last_nadgrids);
+    }
+    
+    last_nadgrids = (char *) pj_malloc(strlen(nadgrids)+1);
+    strcpy( last_nadgrids, nadgrids );
+
+    last_nadgrids_count = 0;
+
+/* -------------------------------------------------------------------- */
+/*      Loop processing names out of nadgrids one at a time.            */
+/* -------------------------------------------------------------------- */
+    for( s = nadgrids; *s != '\0'; )
+    {
+        int   end_char;
+        char  name[128];
+
+        for( end_char = 0; 
+             s[end_char] != '\0' && s[end_char] != ','; 
+             end_char++ ) {}
+
+        if( end_char > sizeof(name) )
+        {
+            pj_errno = -38;
+            return NULL;
+        }
+        
+        strncpy( name, s, end_char );
+        name[end_char] = '\0';
+
+        s += end_char;
+        if( *s == ',' )
+            s++;
+
+        if( !pj_gridlist_merge_gridfile( name ) )
+        {
+            pj_errno = -38;
+            return NULL;
+        }
+    }
+
+    if( last_nadgrids_count > 0 )
+    {
+        *grid_count = last_nadgrids_count;
+        return last_nadgrids_list;
+    }
+    else
+        return NULL;
+}