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 insert_before = nuts . insert_before
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 , current = insert_before ( 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 , current = insert_before ( 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 |
