+# __SyncTeX__

+

+This file is part of the __SyncTeX__ package.

+

+[//]: # (Version: 1.21)

+[//]: # (Date: Sun Oct 15 15:09:55 UTC 2017)

+

+## Important

+

+* Changes in version `1.21`

+

+ * Display query returns more results (as much as `1.18`)

+ * Remove a `\` character from the name of 2 test files.

+ * Change variable name `class` to `class_` because the former is a reserved keyword in C++.

+ * Adding a more portable unused variable management.

+ * Various cosmetic changes in the source code, including explicit declaration of `void` in forward function declaration.

+

+

+* Changes in version `1.20`

+

+ One bug fixed in some initialization and different syntax to make some compilers happy.

+

+* Changes in version `1.19`

+

+ A long standing bug affecting only pdftex has been fixed by adding support to pdf forms. As a side effect, the synchronization algorithm gains in accuracy for all the engines, especially from pdf to source. Of course, there is a small cost in both memory footprint and computational time, but none is noticeable.

+

+ Some technical changes in the API.

+ * more consistent type naming convention

+ * `_s` suffix for struct's

+ * `_p` suffix for pointers

+ * `_t` suffix for standard types

+ * `_f` suffix for functions...

+

+ thus `synctex_node_t` has become `synctex_node_p`.

+

+ * supplemental argument in `synctex_display_query`. Set `page_hint` to the currently displayed pdf page number (0 based). If this info is not available, set `page_hint` to 0, it corresponds to the old behaviour.

+ * rename `synctex_next_result` to `synctex_scanner_next_result`

+ * additional `synctex_parser_private.h` header where

+ more API are exposed. For an advanced usage only (eg parallel synchronizations).

+ * `SYNCTEX_NO_UPDATER` preprocessor macro to deactivate some code useless to frontends.

+

+## What is it ?

+

+The *Synchronization TeXnology* named __SyncTeX__ is a new feature

+of recent __TeX__ engines designed by Jérôme Laurens.

+It allows to synchronize between input and output, which means to

+navigate from the source document to the typeset material and vice versa.

+Browse the source code for more information.

+

+## Contents

+This package is mainly for developers, it contains the following files:

+

+* `synctex_parser_readme.md` (this file)

+* `synctex_parser_version.txt`

+* `synctex_parser_utils.c`

+* `synctex_parser_utils.h`

+* `synctex_parser_local.h`

+* `synctex_parser.h`

+* `synctex_parser_advanced.h`

+* `synctex_parser.c`

+

+The file you are reading contains more informations about the __SyncTeX__ parser history.

+

+## Source

+

+All stable sources are available from [TeXLive repository](http://www.tug.org/svn/texlive/trunk/Build/source/texk/web2c/synctexdir/).

+

+Latest development sources are available from GitHub.

+

+Please notice that due to the complexity of the TeXLive TeX distribution, there might be some delay before synchronization occurs between various repositories.

+

+## Usage

+

+In order to support __SyncTeX__ in a viewer, it is sufficient to include

+in the source the files `synctex_parser.c` and `synctex_parser_utils.c`.

+The synctex parser usage is described in `synctex_parser.h` header file.

+

+More advanced usage is found in `synctex_parser_advanced.h`

+

+The other files are used by tex engines or by the synctex command line utility:

+

+```

+ChangeLog

+README.txt

+am

+man1

+man5

+synctex-common.h

+synctex-convert.sh

+synctex-e-mem.ch0

+synctex-e-mem.ch1

+synctex-e-rec.ch0

+synctex-e-rec.ch1

+synctex-etex.h

+synctex-mem.ch0

+synctex-mem.ch1

+synctex-mem.ch2

+synctex-pdf-rec.ch2

+synctex-pdftex.h

+synctex-rec.ch0

+synctex-rec.ch1

+synctex-rec.ch2

+synctex-tex.h

+synctex-xe-mem.ch2

+synctex-xe-rec.ch2

+synctex-xe-rec.ch3

+synctex-xetex.h

+synctex.c

+synctex.defines

+synctex.h

+synctex_main.c

+tests

+...

+```

+

+## Version:

+

+This is version 1, which refers to the synctex output file format.

+

+The files are identified by a build number.

+In order to help developers to automatically manage the version and build numbers

+and download the parser only when necessary, the `synctex_parser_version.txt`

+is an ASCII text file just containing the current version and build numbers eg `1.19`.

+

+## History:

+

+* 1.1: Thu Jul 17 09:28:13 UTC 2008

+ - First official version available in TeXLive 2008 DVD.

+ Unfortunately, the backwards synchronization is not working properly mainly for ConTeXt users, see below.

+* 1.2: Tue Sep 2 10:28:32 UTC 2008

+ - Correction for ConTeXt support in the edit query.

+ The previous method was assuming that TeX boxes do not overlap,

+ which is reasonable for LaTeX but not for ConTeXt.

+ This assumption is no longer considered.

+* 1.3: Fri Sep 5 09:39:57 UTC 2008

+ - Local variable "read" renamed to "already_read" to avoid conflicts.

+ - "inline" compiler directive renamed to "SYNCTEX_INLINE" for code support and maintenance

+ - _synctex_error cannot be inlined due to variable arguments (thanks Christiaan Hofman)

+ - Correction in the display query, extra boundary nodes are used for a more precise forwards synchronization

+* 1.4: Fri Sep 12 08:12:34 UTC 2008

+ - For an unknown reason, the previous version was not the real 1.3 (as used in iTeXMac2 build 747).

+ As a consequence, a crash was observed.

+ - Some typos are fixed.

+* 1.6: Mon Nov 3 20:20:02 UTC 2008

+ - The bug that prevented synchronization with compressed files on windows has been fixed.

+ - New interface to allow system specific customization.

+ - Note that some APIs have changed.

+* 1.8: Mer 8 jul 2009 11:32:38 UTC

+Note that version 1.7 was delivered privately.

+ - bug fix: synctex was causing a memory leak in pdftex and xetex, thus some processing speed degradation

+ - bug fix: the synctex command line tool was broken when updating a .synctex file

+ - enhancement: better accuracy of the synchronization process

+ - enhancement: the pdf output file and the associated .synctex file no longer need to live in the same directory.

+ The new -d option of the synctex command line tool manages this situation.

+ This is handy when using something like tex -output-directory=DIR ...

+* 1.9: Wed Nov 4 11:52:35 UTC 2009

+ - Various typo fixed

+ - OutputDebugString replaced by OutputDebugStringA to deliberately disable unicode preprocessing

+ - New conditional created because OutputDebugStringA is only available since Windows 2K professional

+* 1.10: Sun Jan 10 10:12:32 UTC 2010

+ - Bug fix in synctex_parser.c to solve a synchronization problem with amsmath's gather environment.

+ Concerns the synctex tool.

+* 1.11: Sun Jan 17 09:12:31 UTC 2010

+ - Bug fix in synctex_parser.c, function synctex_node_box_visible_v: 'x' replaced by 'y'.

+ Only 3rd party tools are concerned.

+* 1.12: Mon Jul 19 21:52:10 UTC 2010

+ - Bug fix in synctex_parser.c, function __synctex_open: the io_mode was modified even in case of a non zero return,

+causing a void .synctex.gz file to be created even if it was not expected. Reported by Marek Kasik concerning a bug on evince.

+* 1.13: Fri Mar 11 07:39:12 UTC 2011

+ - Bug fix in synctex_parser.c, better synchronization as suggested by Jan Sundermeyer (near line 3388).

+ - Stronger code design in synctex_parser_utils.c, function _synctex_get_name (really neutral behavior).

+ Only 3rd party tools are concerned.

+* 1.14: Fri Apr 15 19:10:57 UTC 2011

+ - taking output_directory into account

+ - Replaced FOPEN_WBIN_MODE by FOPEN_W_MODE when opening the text version of the .synctex file.

+ - Merging with LuaTeX's version of synctex.c

+* 1.15: Fri Jun 10 14:10:17 UTC 2011

+This concerns the synctex command line tool and 3rd party developers.

+TeX and friends are not concerned by these changes.

+ - Bug fixed in _synctex_get_io_mode_name, sometimes the wrong mode was returned

+ - Support for LuaTeX convention of './' file prefixing

+* 1.16: Tue Jun 14 08:23:30 UTC 2011

+This concerns the synctex command line tool and 3rd party developers.

+TeX and friends are not concerned by these changes.

+ - Better forward search (thanks Jose Alliste)

+ - Support for LuaTeX convention of './' file prefixing now for everyone, not only for Windows

+* 1.17: Fri Oct 14 08:15:16 UTC 2011

+This concerns the synctex command line tool and 3rd party developers.

+TeX and friends are not concerned by these changes.

+ - synctex_parser.c: cosmetic changes to enhance code readability

+ - Better forward synchronization.

+ The problem occurs for example with LaTeX \item command.

+ The fact is that this command creates nodes at parse time but these nodes are used only

+ after the text material of the \item is displayed on the page. The consequence is that sometimes,

+ forward synchronization spots an irrelevant point from the point of view of the editing process.

+ This was due to some very basic filtering policy, where a somehow arbitrary choice was made when

+ many different possibilities where offered for synchronisation.

+ Now, forward synchronization prefers nodes inside an hbox with as many acceptable spots as possible.

+ This is achieved with the notion of mean line and node weight.

+ - Adding support for the new file naming convention with './'

+ - function `synctex_ignore_leading_dot_slash_in_path replaces` `synctex_ignore_leading_dot_slash`

+ - function `_synctex_is_equivalent_file_name` is more permissive

+ Previously, the function synctex_scanner_get_tag would give an answer only when

+ the given file name was EXACTLY one of the file names listed in the synctex file.

+ The we added some changes accepting for example 'foo.tex' instead of './foo.tex'.

+ Now we have an even looser policy for dealing with file names.

+ If the given file name does not match exactly one the file names of the synctex file,

+ then we try to match the base names. If there is only one match of the base names,

+ then it is taken as a match for the whole names.

+ The base name is defined as following:

+

+ `./foo => foo

+ /my///.////foo => foo

+ /foo => /foo

+ /my//.foo => /my//.foo`

+

+* 1.17: Tue Mar 13 10:10:03 UTC 2012

+ - minor changes, no version changes

+ - syntax man pages are fixed as suggested by M. Shimata

+ see mail to [email protected] titled "syntax.5 has many warnings from groff" and "syntax.1 use invalid macro for mdoc"

+ - 1.17: Tue Jan 14 09:55:00 UTC 2014, fixed a segfault, patch from Sebastian Ramacher

+ - 1.17: Mon Aug 04, fixed a memory leak

+* 1.18: Thu Jun 25 11:36:05 UTC 2015

+ - nested sheets now fully supported (does it make sense in TeX)

+ - cosmetic changes: uniform indentation

+ - suppression of warnings, mainly long/int ones. In short, zlib likes ints when size_t likes longs.

+ - CLI synctex tool can build out of TeXLive (modulo appropriate options passed to the compiler)

+* 1.19: Mon Jul 3 20:03:56 UTC 2017

+ - the nested sheets patch was not a good solution.

+ It has been moved from the parser to the engine.

+ See the `synctex.c` source file for detailed explanations.

+ - there is a new synctex format specification.

+ We can see that a `.synctex` file can contain many times

+ the same vertical position because many objects belong

+ to the same line. When the options read `-synctex=±2` or more,

+ a very basic compression algorithm is used:

+ if synctex is about to write the same number then it writes

+ an `=` sign instead. This saves approximately 10% of the

+ synctex output file, either compressed or not.

+ The new synctex parser has been updated accordingly.

+ Actual tex frontend won't see any difference with the

+ TeX engines that include this new feature.

+ Frontends with the new parser won't see any difference

+ with the older TeX engines.

+ Frontends with the new parser will only see a difference

+ with new TeX engines if `-synctex=±2` or more is used.

+

+## Acknowledgments:

+

+The author received useful remarks from the __pdfTeX__ developers, especially Hahn The Thanh,

+and significant help from __XeTeX__ developer Jonathan Kew.

+

+## Nota Bene:

+

+If you include or use a significant part of the __SyncTeX__ package into a software,

+I would appreciate to be listed as contributor and see __SyncTeX__" highlighted.

+

+Copyright (c) 2008-2017 jerome DOT laurens AT u-bourgogne DOT fr

+