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diff --git a/doc/context/sources/general/manuals/luatex/luatex-introduction.tex b/doc/context/sources/general/manuals/luatex/luatex-introduction.tex index d0899147d..5ed80f4c1 100644 --- a/doc/context/sources/general/manuals/luatex/luatex-introduction.tex +++ b/doc/context/sources/general/manuals/luatex/luatex-introduction.tex @@ -1,7 +1,6 @@ % language=uk \environment luatex-style -\environment luatex-logos \startcomponent luatex-introduction @@ -15,9 +14,9 @@ Additional reference material is published in journals of user groups and It took about a decade to reach stable version 1.0, but for good reason. Successive versions brought new functionality, more control, some cleanup of -internals and experimental features evolved into stable ones or were dropped. +internals. Experimental features evolved into stable ones or were dropped. Already quite early \LUATEX\ could be used for production and it was used on a -daily basis by the authors. Successive versions sometimes demanded a adaption to +daily basis by the authors. Successive versions sometimes demanded an adaption to the \LUA\ interfacing, but the concepts were unchanged. The current version can be considered stable in functionality and there will be no fundamental changes. Of course we then can decide to move towards version 2.00 with different @@ -26,9 +25,10 @@ properties. Don't expect \LUATEX\ to behave the same as \PDFTEX ! Although the core functionality of that 8 bit engine was starting point, it has been combined with the directional support of \OMEGA\ (\ALEPH). But, \LUATEX\ can behave different -due to its wide (32 bit) characters, many registers and large memory support. -There is native \UTF\ input, support for large (more that 8 bit) fonts, and the -math machinery is tuned for \OPENTYPE\ math. There is support for directional +due to its wide (32 bit) characters, many registers and large memory support. The +\PDF\ code produced differs from \PDFTEX\ but users will normally not notice +that. There is native \UTF\ input, support for large (more than 8 bit) fonts, and +the math machinery is tuned for \OPENTYPE\ math. There is support for directional typesetting too. The log output can differ from other engines and will likely differ more as we move forward. When you run plain \TEX\ for sure \LUATEX\ runs slower than \PDFTEX\ but when you run for instance \CONTEXT\ \MKIV\ in many cases @@ -47,27 +47,29 @@ The organization of the source code is adapted so that it can glue all these components together. We continue cleaning up side effects of the accumulated code in \TEX\ engines (especially code that is not needed any longer). -\startitemize[packed] +\startitemize [unpacked] \startitem - Most of \PDFTEX\ version 1.40.9, converted to \CCODE. Some experimental - features have been removed and some utility macros are not inherited as - their functionality can be done in \LUA. The number of backend interface - commands has been reduced to a few. The extensions are separated from the - core (which we keep close to the original \TEX\ core). Some mechanisms - like expansion and protrusion can behave different from the original due - to some cleanup and optimization. Some whatsit based functionality (image - support and reusable content) is now core functionality. + We started out with most of \PDFTEX\ version 1.40.9. The code base was + converted to \CCODE\ and split in modules. Experimental features were + removed and utility macros are not inherited because their functionality + can be programmed in \LUA. The number of backend interface commands has + been reduced to a few. The so called extensions are separated from the + core (which we try to keep close to the original \TEX\ core). Some + mechanisms like expansion and protrusion can behave different from the + original due to some cleanup and optimization. Some whatsit based + functionality (image support and reusable content) is now core + functionality. We don't stay in sync with \PDFTEX\ development. \stopitem \startitem - The direction model and some other bits from \ALEPH\ RC4 (derived from - \OMEGA) is included. The related primitives are part of core \LUATEX\ but - at the node level directional support is no longer based on so called - whatsits but on real nodes. In fact, whatsits are now only used for - backend specific extensions. + The direction model from \ALEPH\ RC4 (which is derived from \OMEGA) is + included. The related primitives are part of core \LUATEX\ but at the + node level directional support is no longer based on so called whatsits + but on real nodes with relevant properties. The number of directions is + limited to the useful set and the backend has been made direction aware. \stopitem \startitem Neither \ALEPH's I/O translation processes, nor tcx files, nor \ENCTEX\ - can be used, these encoding|-|related functions are superseded by a + are available. These encoding|-|related functions are superseded by a \LUA|-|based solution (reader callbacks). In a similar fashion all file \IO\ can be intercepted. \stopitem @@ -80,14 +82,18 @@ code in \TEX\ engines (especially code that is not needed any longer). \startitem There are various \TEX\ extensions but only those that cannot be done using the \LUA\ interfaces. The math machinery often has two code paths: - one traditional and the other more suitable for wide \OPENTYPE\ fonts. + one traditional and the other more suitable for wide \OPENTYPE\ fonts. Here + we follow the \MICROSOFT\ specifications as much as possible. Some math + functionality has been opened up a bit so that users have more control. \stopitem \startitem The fontloader uses parts of \FONTFORGE\ 2008.11.17 combined with additional code specific for usage in a \TEX\ engine. We try to minimize specific font support to what \TEX\ needs: character references and dimensions and delegate everything else to \LUA. That way we keep \TEX\ - open for extensions without touching the core. + open for extensions without touching the core. In order to minimize + dependencies at some point we may decide to make this an optional + library. \stopitem \startitem The \METAPOST\ library is integral part of \LUATEX. This gives \TEX\ some @@ -95,33 +101,71 @@ code in \TEX\ engines (especially code that is not needed any longer). Again \LUA\ is used as glue between the frontend and backend. Further development of \METAPOST\ is closely related to \LUATEX. \stopitem + \startitem + The virtual font technology that comes with \TEX\ has been integrated + into the font machinery in a way that permits creating virtual fonts + at runtime. Because \LUATEX\ can also act as a \LUA\ interpreter this + means that a complete \TEX\ workflow can be built without the need for + additional programs. + \stopitem + \startitem + The versions starting from 1.09 no longer use the poppler library for + inclusion but a lightweight dedicated one. This removes a dependency but + also makes the inclusion code of \LUATEX\ different from \PDFTEX. In fact + it was already much different due to the \LUA\ image interfacing. + \stopitem \stopitemize We try to keep upcoming versions compatible but intermediate releases can contain -experimental features. A general rule is that versions that end up on \TEX live -and|/|or are released around \CONTEXT\ meetings are stable. Future versions will -probably become a bit leaner and meaner. Some libraries might become external as -we don't want to bloat the binary and also don't want to add more hard coded -solutions. After all, with \LUA\ you can extend the core functionality. The less -dependencies, the better. - -The \TEXLIVE\ version is to be considered the current stable version. Any version -between the yearly \TEXLIVE\ releases are to be considered beta. The beta -releases are normally available via the \CONTEXT\ distribution channels (the -garden and so called minimals). - -\blank[1*big] - -Hans Hagen, Harmut Henkel, \crlf -Taco Hoekwater \& Luigi Scarso +experimental features. A general rule is that versions that end up on \TEXLIVE\ +and|/|or are released around \CONTEXT\ meetings are stable. Any version between +the yearly \TEXLIVE\ releases are to be considered beta and in the repository end +up as trunk releases. We have an experimental branch that we use for development +but there is no support for any of its experimental features. Intermediate +releases (from trunk) are normally available via the \CONTEXT\ distribution +channels (the garden and so called minimals). + +Version 1.10 is more or less an endpoint in development: this is what you get. +Because not only \CONTEXT, that we can adapt rather easily, uses \LUATEX, we +cannot change fundamentals without unforeseen consequences. By now it has been +proven that \LUA\ can be used to extend the core functionality so there is no +need to add more, and definitely no hard coded solutions for (not so) common +problems. Of course there will be bug fixes, maybe some optimization, and there +might even be some additions or non|-|intrusive improvements, but only after +testing outside the stable release. After all, the binary is already more than +large enough and there is not that much to gain. + +You might find \LUA\ helpers that are not yet documented. These are considered +experimental, although when you encounter them in a \CONTEXT\ version that has +been around for a while you can assume that they will stay. Of course it can just +be that we forgot to document them yet. + +A manual like this is not really meant as tutorial, for that we refer to +documents that ship with \CONTEXT, articles, etc. It is also never complete +enough for all readers. We try to keep up but the reader needs to realize that +it's all volunteer work done in spare time. And for sure, complaining about a bad +manual or crappy documentation will not really motivate us to spend more time on +it. That being said, we hope that this document is useful. + +\blank[big] + +\testpage[5] + +\startlines +Hans Hagen +Harmut Henkel +Taco Hoekwater +Luigi Scarso +\stoplines \blank[3*big] -\starttabulate +\starttabulate[|||] \NC Version \EQ \currentdate \NC \NR -\NC \LUATEX \EQ version \cldcontext{status.luatex_version/100}, - revision \cldcontext{status.luatex_revision}, - number \cldcontext{environment.luatexversion} \NC \NR +\NC \LUATEX \EQ \cldcontext{LUATEXENGINE} % + \cldcontext{LUATEXVERSION} / % + \cldcontext{LUATEXFUNCTIONALITY} + \NC \NR \NC \CONTEXT \EQ MkIV \contextversion \NC \NR \stoptabulate |