[libpng16] Added png_set_itxt() (work in progress)

ANNOUNCE

@@ -319,6 +319,7 @@ Version 1.6.0beta18 [March 16, 2012]
     this is disabled in which case the simplified API can't be built.)
 
 Version 1.6.0beta19 [March 16, 2012]
+  Added png_set_itxt() (work in progress)
 
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CHANGES

@@ -4070,6 +4070,7 @@ Version 1.6.0beta18 [March 16, 2012]
     this is disabled in which case the simplified API can't be built.)
 
 Version 1.6.0beta19 [March 16, 2012]
+  Added png_set_itxt() (work in progress)
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

example.c

@@ -863,6 +863,13 @@ void write_png(char *file_name /* , ... other image information ... */)
     */
    png_set_gAMA(png_ptr, info_ptr, gamma);
 
+#if PNG_LIBPNG_VER >= 1.6.0
+   png_set_itxt(png_ptr, info_ptr, 0, 0, "Title", "Mona Lisa", NULL, NULL); 
+   png_set_itxt(png_ptr, info_ptr, 0, 0, "Author", "Leonardo da Vinci", NULL,
+       NULL);
+   png_set_itxt(png_ptr, info_ptr, 3, 0, "Description", "<long text>", NULL,
+       NULL);
+#else
    /* Optionally write comments into the image */
    {
       png_text text_ptr[3];
@@ -896,6 +903,7 @@ void write_png(char *file_name /* , ... other image information ... */)
 
       png_set_text(write_ptr, write_info_ptr, text_ptr, 3);
    }
+#endif
 
    /* Other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs */
 

png.h

@@ -2263,6 +2263,13 @@ PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
     png_inforp info_ptr, png_const_textp text_ptr, int num_text));
 #endif
 
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+PNG_EXPORT(243, void, png_set_itxt, (png_const_structrp png_ptr,
+    png_inforp info_ptr, const int in_flag, const int in_method,
+    png_const_charp in_key, png_const_charp in_text, png_const_charp in_lang,
+    png_const_charp in_lang_key));
+#endif
+
 #ifdef PNG_tIME_SUPPORTED
 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
     png_inforp info_ptr, png_timep *mod_time));
@@ -3081,7 +3088,7 @@ PNG_EXPORT(242, void, png_set_check_for_invalid_index,
  * scripts/symbols.def as well.
  */
 #ifdef PNG_EXPORT_LAST_ORDINAL
-  PNG_EXPORT_LAST_ORDINAL(242);
+  PNG_EXPORT_LAST_ORDINAL(243);
 #endif
 
 #ifdef __cplusplus

pngwrite.c

@@ -1410,6 +1410,75 @@ png_set_text_compression_method(png_structrp png_ptr, int method)
 #endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
 /* end of API added to libpng-1.5.4 */
 
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+/* TO DO: synopsis in libpng.3
+ *        revise example.c
+ *        set up some macros to use instead of 0,1,2,3
+ *        test, test, test
+ */
+/* API added to libpng-1.6.0 */
+void PNGAPI
+png_set_itxt(png_const_structrp png_ptr, png_inforp info_ptr,
+    const int in_flag, const int in_method, png_const_charp in_key,
+    png_const_charp in_text, png_const_charp in_lang,
+    png_const_charp in_lang_key)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+   {
+      png_text text_ptr[1];
+      char *key = (png_charp) in_key;
+      char *text = (png_charp) in_text;
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+      char *lang = (png_charp) in_lang;
+      char *lang_key = (png_charp) in_lang_key;
+#endif
+      text_ptr[0].key = key;
+      text_ptr[0].text = text;
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+      text_ptr[0].lang = lang;
+      text_ptr[0].lang_key = lang_key;
+#endif
+
+      /*
+       TO DO: use macros for these.
+      -1: tEXt, none
+       0: zTXt, deflate
+       1: iTXt, none
+       2: iTXt, deflate
+       */
+
+      if (in_method != 0)
+        png_benign_error(png_ptr,
+            "Only text compression method 0 is supported, using 0.");
+
+      if (in_flag == 0)
+        text_ptr[0].compression = -1;
+
+      else if (in_flag == 1)
+        text_ptr[0].compression = 0;
+
+      else if (in_flag == 2)
+        text_ptr[0].compression = 1;
+
+      else if (in_flag == 3)
+        text_ptr[0].compression = 2;
+
+      else
+      {
+        png_benign_error(png_ptr,
+            "Unrecognized text compression flag, using (compressed iTXt).");
+        text_ptr[0].compression = 2;
+      }
+
+      png_debug(1, "in png_set_itxt");
+
+      /* TO DO: fix compiler warning about discarding qualifier here */
+      png_set_text(png_ptr, info_ptr, text_ptr, 1);
+   }
+  
+}
+#endif
+
 void PNGAPI
 png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn)
 {

scripts/symbols.def

@@ -248,3 +248,4 @@ EXPORTS
  png_image_write_to_stdio @240
  png_convert_to_rfc1123_buffer @241
  png_set_check_for_invalid_index @242
+ png_set_itxt @243