From 3123dc09229c80649965b717a7d28a9857454368 Mon Sep 17 00:00:00 2001
From: Frank Warmerdam <warmerdam@pobox.com>
Date: Sun, 24 Feb 2002 16:13:39 +0000
Subject: [PATCH] New

---
 libtiff/tif_extension.c | 109 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 libtiff/tif_extension.c

diff --git a/libtiff/tif_extension.c b/libtiff/tif_extension.c
new file mode 100644
index 00000000..e5f32351
--- /dev/null
+++ b/libtiff/tif_extension.c
@@ -0,0 +1,109 @@
+/* $Header: /cvs/maptools/cvsroot/libtiff/libtiff/tif_extension.c,v 1.1 2002-02-24 16:13:39 warmerda Exp $ */
+
+/*
+ * Copyright (c) 1988-1997 Sam Leffler
+ * Copyright (c) 1991-1997 Silicon Graphics, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and 
+ * its documentation for any purpose is hereby granted without fee, provided
+ * that (i) the above copyright notices and this permission notice appear in
+ * all copies of the software and related documentation, and (ii) the names of
+ * Sam Leffler and Silicon Graphics may not be used in any advertising or
+ * publicity relating to the software without the specific, prior written
+ * permission of Sam Leffler and Silicon Graphics.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
+ * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
+ * 
+ * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
+ * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
+ * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+ * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
+ * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
+ * OF THIS SOFTWARE.
+ */
+
+/*
+ * TIFF Library.
+ *
+ * Various routines support external extension of the tag set, and other
+ * application extension capabilities. 
+ */
+
+#include "tiffiop.h"
+
+int TIFFGetTagListCount( TIFF *tif )
+
+{
+    TIFFDirectory* td = &tif->tif_dir;
+    
+    return td->td_customValueCount;
+}
+
+ttag_t TIFFGetTagListEntry( TIFF *tif, int tag_index )
+
+{
+    TIFFDirectory* td = &tif->tif_dir;
+
+    if( tag_index < 0 || tag_index >= td->td_customValueCount )
+        return -1;
+    else
+        return td->td_customValues[tag_index].info->field_tag;
+}
+
+/*
+** This provides read/write access to the TIFFTagMethods within the TIFF
+** structure to application code without giving access to the private
+** TIFF structure.
+*/
+TIFFTagMethods *TIFFAccessTagMethods( TIFF *tif )
+
+{
+    return &(tif->tif_tagmethods);
+}
+
+void *TIFFGetClientInfo( TIFF *tif, const char *name )
+
+{
+    TIFFClientInfoLink *link = tif->tif_clientinfo;
+
+    while( link != NULL && strcmp(link->name,name) != 0 )
+        link = link->next;
+
+    if( link != NULL )
+        return link->data;
+    else
+        return NULL;
+}
+
+void TIFFSetClientInfo( TIFF *tif, void *data, const char *name )
+
+{
+    TIFFClientInfoLink *link = tif->tif_clientinfo;
+
+    /*
+    ** Do we have an existing link with this name?  If so, just
+    ** set it.
+    */
+    while( link != NULL && strcmp(link->name,name) != 0 )
+        link = link->next;
+
+    if( link != NULL )
+    {
+        link->data = data;
+        return;
+    }
+
+    /*
+    ** Create a new link.
+    */
+
+    link = _TIFFmalloc(sizeof(TIFFClientInfoLink));
+    link->next = tif->tif_clientinfo;
+    link->name = _TIFFmalloc(strlen(name)+1);
+    strcpy( link->name, name );
+    link->data = data;
+
+    tif->tif_clientinfo = link;
+}