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1% language=us runpath=texruns:manuals/colors
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3\startcomponent colors-introduction
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5\environment colors-environment
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7\startchapter[title=Introduction][color=darkgray]
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9This manual fits in the series where we discus fundamental subsystems like fonts
10and languages. Here we will collect the more technical backgrounds. This document
11is not meant as a manual for users who start with \CONTEXT, for that we have
12other manuals.
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14Color has a rather long history in \CONTEXT\ because we supported it right from
15the start. In the times that \DVI\ backend drivers were used, specials were the
16way to force color in the result. However, each driver had different demands:
17some expected specific color directives, others a sequence of for instance
18\POSTSCRIPT\ commands. When \PDF\ showed up, resource management entered the
19game. Because ot always used a backend driver model in \CONTEXT, it could easily
20be adapted. All management, for instance of nested colors, was done in \TEX\
21code. If advanced color support hadn't been available right from the start, we'd
22probably not be using \TEX\ now.
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24In \MKIV\ color support was implemented from scratch but in a for the user
25downward compatible way. In that respect this manual is not going to reveal
26anything revolutionary. Much of the work is now delegated to \LUA\ and because of
27that directives are no longer part of the (expanded) input stream. As a result
28color is now more robust and less intrusive.
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30Because \METAPOST\ support is well integrated, we also communicate colors to
31\METAPOST. In \MKIV\ the communication between the two engines was upgraded and
32hopefully evolved into an (even) more convenient interface.
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34External graphics are in fact islands in the document flow: they manage their
35resources like colors themselves. However, there are some ways to deal with the
36demands of publishers and printers with respect to colors. These will be
37discussed too.
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39\getbuffer[underconstruction]
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41\startlines
42Hans Hagen
43PRAGMA ADE, Hasselt NL
442016
45\stoplines
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47\stopchapter
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49\stopcomponent
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