1if not modules then modules = { } end modules ['typo-fkr'] = {
2 version = 1.001,
3 comment = "companion to typo-fkr.mkiv",
4 author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
5 copyright = "PRAGMA ADE / ConTeXt Development Team",
6 license = "see context related readme files"
7}
8
9local nuts = nodes.nuts
10local getid = nuts.getid
11local getnext = nuts.getnext
12local getattr = nuts.getattr
13local isglyph = nuts.isglyph
14
15local nodecodes = nodes.nodecodes
16local glyph_code = nodecodes.glyph
17
18local fontdata = fonts.hashes.identifiers
19local getkernpair = fonts.handlers.otf.getkern
20
21local insertbefore = nuts.insertbefore
22local new_kern = nuts.pool.fontkern
23
24local enableaction = nodes.tasks.enableaction
25
26local a_extrakern = attributes.private("extrafontkern")
27
28
29
30typesetters.fontkerns = { }
31
32function typesetters.fontkerns.handler(head)
33 local current = head
34 local lastfont = nil
35 local lastchar = nil
36 local lastdata = nil
37 while current do
38 local char, font = isglyph(current)
39 if char then
40 local a = getattr(current,a_extrakern)
41 if a then
42 if font ~= lastfont then
43 if a > 0 and lastchar then
44 if not lastdata then
45 lastdata = fontdata[lastfont]
46 end
47 local kern = nil
48 local data = fontdata[font]
49 local kern1 = getkernpair(lastdata,lastchar,char)
50 local kern2 = getkernpair(data,lastchar,char)
51 if a == 1 then
52 kern = kern1 > kern2 and kern2 or kern1
53 elseif a == 2 then
54 kern = kern1 > kern2 and kern1 or kern2
55 else
56 kern = (kern1 + kern2)/2
57 end
58 if kern ~= 0 then
59 head = insertbefore(head,current,new_kern(kern))
60 end
61 lastdata = data
62 else
63 lastdata = nil
64 end
65 elseif lastchar then
66 if not lastdata then
67 lastdata = fontdata[lastfont]
68 end
69 local kern = getkernpair(lastdata,lastchar,char)
70 if kern ~= 0 then
71 head = insertbefore(head,current,new_kern(kern))
72 end
73 end
74 lastchar = char
75 lastfont = font
76 elseif lastfont then
77 lastfont = nil
78 lastchar = nil
79 lastdata = nil
80 end
81 elseif lastfont then
82 lastfont = nil
83 lastchar = nil
84 lastdata = nil
85 end
86 current = getnext(current)
87 end
88 return head
89end
90
91if context then
92
93 local variables = interfaces.variables
94 local unsetvalue = attributes.unsetvalue
95 local enabled = false
96 local setattribute = tex.setattribute
97
98 local values = {
99 [variables.none ] = 0,
100 [variables.min ] = 1,
101 [variables.max ] = 2,
102 [variables.mixed] = 3,
103 [variables.reset] = unsetvalue,
104 }
105
106 local function setextrafontkerns(str)
107 if not enabled then
108 enableaction("processors","typesetters.fontkerns.handler")
109 enabled = true
110 end
111 setattribute(a_extrakern,values[str] or unsetvalue)
112 end
113
114 interfaces.implement {
115 name = "setextrafontkerns",
116 arguments = "string",
117 actions = setextrafontkerns,
118 }
119
120end
121 |
