# HG changeset patch
# User magedrifaat <magedrifaat@gmail.com>
# Date 1660694244 -7200
# Node ID c07461ca34d61853275b4c2a67953c3199b0b02e
# Parent  ed329571ec88aab5dfc79ee150f5d7b537057dd6
Tiff: add support for oppening tiff files in r+ mode

* __tiff__.cc (F__tif_open__): added support for r+
for opeening tiff files for both reading and writing.

diff -r ed329571ec88 -r c07461ca34d6 libinterp/corefcn/__tiff__.cc
--- a/libinterp/corefcn/__tiff__.cc	Tue Aug 16 22:57:21 2022 +0200
+++ b/libinterp/corefcn/__tiff__.cc	Wed Aug 17 01:57:24 2022 +0200
@@ -2053,15 +2053,17 @@
     if (nargin == 2)
       mode = args(1).string_value ();
 
-    const std::vector<std::string> supported_modes {"r", "w", "w8", "a"};
+    const std::vector<std::string> supported_modes {"r", "w", "w8", "a", "r+"};
       
     if (std::find (supported_modes.cbegin (), supported_modes.cend (), mode)
           == supported_modes.cend ())
+      error ("Invalid mode for openning Tiff file: %s", mode.c_str ());
+    
+    bool is_rplus = false;
+    if (mode == "r+")
       {
-        if (mode == "r+")
-          error ("Openning files in r+ mode is not yet supported");
-        else
-          error ("Invalid mode for openning Tiff file: %s", mode.c_str ());
+        is_rplus = true;
+        mode = "a";
       }
     
     // LibTIFF does Strip chopping by default, which makes the organization of
@@ -2073,6 +2075,10 @@
     
     if (! tif)
       error ("Failed to open Tiff file\n");
+    
+    // TODO(maged): check of there is more to be done for r+
+    if (is_rplus && ! TIFFSetDirectory (tif, 0))
+      error ("Failed to open Tiff file\n");
 
     // TODO(maged): use inheritance of octave_base_value instead
     octave_value tiff_ov = octave_value ((uint64_t)tif);
@@ -3078,9 +3084,6 @@
     
     TIFF *tif = (TIFF *)(args(0).uint64_value ());
     
-    // TODO(maged): check if matlab requires scalar double
-    // matlab expects double, uint32, or uint64
-    // and checks the subIFD tag first
     if (! args(1).is_double_type () && ! args(1).is_uint32_type ()
         && ! args(1).is_uint64_type ())
       error ("Expected offset of type double, uint32 or uint64");