1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
%D \module [
%D file=t-letterspace,
%D version=2013-03-27 22:55:19+0100 or later,
%D title=\CONTEXT\ User Module,
%D subtitle=Letterspacing commands,
%D author=Philipp Gesang,
%D date=\currentdate,
%D copyright=Philipp Gesang,
%D license=2-clause BSD,
%D ]
%C Read the license conditions in the file \type{COPYING}.
\writestatus{loading}{ConTeXt User Module / Letterspace}
\startmodule [letterspace]
\startinterface all
\setinterfacevariable {letterspace} {letterspace}
\setinterfacevariable {factor} {factor}
\setinterfacevariable {spaceskip} {spaceskip}
\setinterfacevariable {suppresskern}{suppresskern}
\stopinterface
\unprotect
\definenamespace [\v!letterspace] [
command=yes,
comment=Letterspace module,
name=\v!letterspace,
\s!parent=\v!letterspace,
setup=list,
style=no,
type=module,
version=hg-rev:3+,
]
%D \macros
%D {letterspace}
%D
%D \useURL [wschuster] [https://bitbucket.org/wolfs/] [] [Wolfgang Schuster]
%D \from[wschuster]’s {\em fancybreak} and {\em annotation}
%D modules served as the primary source for the following code.
%D You’ll have to thank him if it works and blame me if it doesn’t.
\appendtoks
\setuevalue{\currentletterspace }{\letterspace_cmd[\currentletterspace]}%
\setuevalue{\e!start\currentletterspace}{\letterspace_env_start[\currentletterspace]}%
\setuevalue{\e!stop \currentletterspace}{\letterspace_env_stop}%
\to \everydefineletterspace
\definecharacterkerning [letterspace:current]
\unexpanded\def\letterspace_cmd[#id]{%
\edef\currentletterspace{#id}%
\dosingleempty\letterspace_cmd_parameters%
}
\def\letterspace_cmd_parameters[#parms]{%
\iffirstargument
\doifassignmentelse{#parms}{%
\setupletterspace[\currentletterspace][#parms]%
}\relax
\fi
\letterspace_cmd_content%
}
\definefontfeature [letterspace:kerning] [kern=yes]
\def\letterspace_truevalues{true,yep,yes}
\def\letterspace_cmd_content#obj{%
\def\currentobject{#obj}%
\dontleavehmode
\setupcharacterkerning[letterspace:current][factor=\letterspaceparameter{factor}]%
\def\letterspace_setstuff{%
\setcharacterkerning[letterspace:current]%
\advance \spaceskip \letterspaceparameter{spaceskip}%
\advance \xspaceskip \letterspaceparameter{spaceskip}%
\doifinset{\letterspaceparameter{suppresskern}}{\letterspace_truevalues}{%
\subtractfontfeaturefromfont{letterspace:kerning}%
}%
}%
\ifhmode\ifnum\lastnodetype=\gluenodecode
\unskip{\letterspace_setstuff\ }%
\fi
\fi%
{\letterspace_setstuff\currentobject}%
\doifnextspace{%
{\letterspace_setstuff\ }%
\gobblespacetokens%
}%
}
%D This is a partial ripoff of a couple of macros from
%D \type{syst-aux.mkiv}.
%D \useURL [flet] [http://www.tug.org/TUGboat/Articles/tb09-3/tb22bechtolsheim.pdf] [] [\type{futurelet}]
%D Very helpful for further understanding of what’s exactly going
%D on: Stephan von Bechtolsheim’s tutorial on \from[flet].
%D
%D In short: the trick is checking whether the token following
%D the command is a space, that is: whether it expands to
%D \type{\blankspace}. If the test succeeds, a space will be
%D added that has the correct parameters and all space tokens
%D following the command will be gobbled. Otherwise -- the next
%D token being anything else -- \type{\letterspace} will proceed
%D without changing anything.
\def\doifnextspace#tok{%
\def\!!string{#tok}%
\futurelet\nexttoken\inspectnexttoken%
}
\def\inspectnexttoken{%
\ifx\nexttoken\blankspace
\@EA\!!string
\fi%
}
%D \macros
%D {startletterspace,stopletterspace}
%D
%D These rely even more shamelessly on \from[wschuster]’s code
%D from the {\em fancybreak} module.
%D
%D The \type{\[start|stop]letterspace} environment is provided
%D for sake of completeness.
\unexpanded\def\letterspace_env_start[#id]{%
\edef\currentletterspace{#id}%
\dosingleempty\letterspace_env_start_indeed%
}
\def\letterspace_env_start_indeed[#parms]{%
\iffirstargument
\setupletterspace[\currentletterspace][#parms]%
\fi
\letterspace_cmd_content\bgroup%
}
\let\letterspace_env_stop\egroup
%D \macros
%D {setupletterspace}
%D
%D Initial setup.
%D The factor by which the {\em letter space} (i.e. space between
%D glyphs) will be increased is specified via the
%D \type{factor} key.
%D Additionally, it is wise with respect to legibility to enlarge
%D the {\em interword space} as well. That is what the
%D \type{spaceskip} key is for. The {\em spaceskip} should be an
%D ordinary dimension.
\setupletterspace [
\v!factor=.125,
\v!spaceskip=.5em,
\v!suppresskern=false,
]
\defineletterspace[\v!letterspace]
\protect \stopmodule \endinput
% vim:ft=context:sw=2:ts=2
|
