summaryrefslogtreecommitdiff
path: root/tex/context/base/mkiv/font-imp-italics.lua
blob: 8b38c5893b64499a115fac9797b697ecf2f90fff (plain)
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
if not modules then modules = { } end modules ['font-imp-italics'] = {
    version   = 1.001,
    comment   = "companion to font-ini.mkiv and hand-ini.mkiv",
    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
    copyright = "PRAGMA ADE / ConTeXt Development Team",
    license   = "see context related readme files"
}

local next, tonumber = next, tonumber

local fonts              = fonts
local handlers           = fonts.handlers
local registerotffeature = handlers.otf.features.register
local registerafmfeature = handlers.afm.features.register

-- This is a precursor to what we do in lmtx now via tweaks but at some point I
-- might make this a mkiv features too using staircase kerns.

-- local function initialize(tfmdata,key,value)
--     local factor = tonumber(value) or 1
--     for unicode, character in next, tfmdata.characters do
--         local olditalic = character.italic
--         if olditalic and olditalic ~= 0 then
--             character.width       = character.width + olditalic
--             character.italic      = 0
--             character.bottomright = -factor * olditalic -- lmtx only
--         end
--     end
-- end
--
-- local specification = {
--     name        = "italicwidths",
--     description = "add italic to width",
--     manipulators = {
--         base = initialize,
--         node = initialize, -- only makes sense for math
--     }
-- }
--
-- registerotffeature(specification)
-- registerafmfeature(specification)

local function initialize(tfmdata,value) -- hm, always value
    if value then
        -- the magic 40 and it formula come from Dohyun Kim but we might need another guess
        local parameters = tfmdata.parameters
        local italicangle = parameters.italicangle
        if italicangle and italicangle ~= 0 then
            local properties = tfmdata.properties
            local factor = tonumber(value) or 1
            properties.hasitalics = true
            properties.autoitalicamount = factor * (parameters.uwidth or 40)/2
        end
    end
end

local specification = {
    name         = "itlc",
    description  = "italic correction",
    initializers = {
        base = initialize,
        node = initialize,
    }
}

registerotffeature(specification)
registerafmfeature(specification)

if context then

    local function initialize(tfmdata,value) -- yes no delay
        tfmdata.properties.textitalics = toboolean(value)
    end

    local specification = {
        name         = "textitalics",
        description  = "use alternative text italic correction",
        initializers = {
            base = initialize,
            node = initialize,
        }
    }

    registerotffeature(specification)
    registerafmfeature(specification)

    -- only used when testing

    local letter = characters.is_letter
    local always = true

    local function collapseitalics(tfmdata,key,value)
        local threshold = value == true and 100 or tonumber(value)
        if threshold and threshold > 0 then
            if threshold > 100 then
                threshold = 100
            end
            for unicode, data in next, tfmdata.characters do
                if always or letter[unicode] or letter[data.unicode] then
                    local italic = data.italic
                    if italic and italic ~= 0 then
                        local width = data.width
                        if width and width ~= 0 then
                            local delta = threshold * italic / 100
                            data.width  = width  + delta
                            data.italic = italic - delta
                        end
                    end
                end
            end
        end
    end

    local dimensions_specification = {
        name        = "collapseitalics",
        description = "collapse italics",
        manipulators = {
            base = collapseitalics,
            node = collapseitalics,
        }
    }

    registerotffeature(dimensions_specification)
    registerafmfeature(dimensions_specification)

end