-# __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

-