font-oti.lua /size: 7904 b    last modification: 2020-07-01 14:35
1if not modules then modules = { } end modules ['font-oti'] = {
2    version   = 1.001,
3    comment   = "companion to font-ini.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 lower = string.lower
10
11local fonts              = fonts
12local constructors       = fonts.constructors
13
14local otf                = constructors.handlers.otf
15local otffeatures        = constructors.features.otf
16local registerotffeature = otffeatures.register
17
18local otftables          = otf.tables or { }
19otf.tables               = otftables
20
21local allocate           = utilities.storage.allocate
22
23registerotffeature {
24    name        = "features",
25    description = "initialization of feature handler",
26    default     = true,
27}
28
29-- these are later hooked into node and base initializaters
30
31local function setmode(tfmdata,value)
32    if value then
33        tfmdata.properties.mode = lower(value)
34    end
35end
36
37otf.modeinitializer = setmode
38
39local function setlanguage(tfmdata,value)
40    if value then
41        local cleanvalue = lower(value)
42        local languages  = otftables and otftables.languages
43        local properties = tfmdata.properties
44        if not languages then
45            properties.language = cleanvalue
46        elseif languages[value] then
47            properties.language = cleanvalue
48        else
49            properties.language = "dflt"
50        end
51    end
52end
53
54local function setscript(tfmdata,value)
55    if value then
56        local cleanvalue = lower(value)
57        local scripts    = otftables and otftables.scripts
58        local properties = tfmdata.properties
59        if not scripts then
60            properties.script = cleanvalue
61        elseif scripts[value] then
62            properties.script = cleanvalue
63        else
64            properties.script = "dflt"
65        end
66    end
67end
68
69registerotffeature {
70    name        = "mode",
71    description = "mode",
72    initializers = {
73        base = setmode,
74        node = setmode,
75        plug = setmode,
76    }
77}
78
79registerotffeature {
80    name         = "language",
81    description  = "language",
82    initializers = {
83        base = setlanguage,
84        node = setlanguage,
85        plug = setlanguage,
86    }
87}
88
89registerotffeature {
90    name        = "script",
91    description = "script",
92    initializers = {
93        base = setscript,
94        node = setscript,
95        plug = setscript,
96    }
97}
98
99-- here (as also in generic
100
101otftables.featuretypes = allocate {
102    gpos_single              = "position",
103    gpos_pair                = "position",
104    gpos_cursive             = "position",
105    gpos_mark2base           = "position",
106    gpos_mark2ligature       = "position",
107    gpos_mark2mark           = "position",
108    gpos_context             = "position",
109    gpos_contextchain        = "position",
110    gsub_single              = "substitution",
111    gsub_multiple            = "substitution",
112    gsub_alternate           = "substitution",
113    gsub_ligature            = "substitution",
114    gsub_context             = "substitution",
115    gsub_contextchain        = "substitution",
116    gsub_reversecontextchain = "substitution",
117    gsub_reversesub          = "substitution",
118}
119
120function otffeatures.checkeddefaultscript(featuretype,autoscript,scripts)
121    if featuretype == "position" then
122        local default = scripts.dflt
123        if default then
124            if autoscript == "position" or autoscript == true then
125                return default
126            else
127                report_otf("script feature %s not applied, enable default positioning")
128            end
129        else
130            -- no positioning at all
131        end
132    elseif featuretype == "substitution" then
133        local default = scripts.dflt
134        if default then
135            if autoscript == "substitution" or autoscript == true then
136                return default
137            end
138        end
139    end
140end
141
142function otffeatures.checkeddefaultlanguage(featuretype,autolanguage,languages)
143    if featuretype == "position" then
144        local default = languages.dflt
145        if default then
146            if autolanguage == "position" or autolanguage == true then
147                return default
148            else
149                report_otf("language feature %s not applied, enable default positioning")
150            end
151        else
152            -- no positioning at all
153        end
154    elseif featuretype == "substitution" then
155        local default = languages.dflt
156        if default then
157            if autolanguage == "substitution" or autolanguage == true then
158                return default
159            end
160        end
161    end
162end
163
164-- the following might become available generic in due time but for now
165-- this is some context playground (development code)
166
167-- if not context then
168--     return
169-- end
170
171-- local helpers        = otf.readers.helpers
172-- local axistofactors  = helpers.axistofactors
173-- local normalizedaxis = helpers.normalizedaxis
174-- local getaxisscale   = helpers.getaxisscale
175-- local cleanname      = containers.cleanname
176
177-- local function validvariable(tfmdata)
178--     if tfmdata.properties.factors then
179--         return
180--     end
181--     local resources    = tfmdata.resources
182--     local variabledata = resources and resources.variabledata
183--     if not variabledata then
184--         return
185--     end
186--     local instances = variabledata.instances
187--     local axis      = variabledata.axis
188--     local segments  = variabledata.segments
189--     if instances and axis then
190--         return instances, axis, segments
191--     end
192-- end
193
194-- local function initializeinstance(tfmdata,value)
195--     if type(value) == "string" then
196--         local instances, axis, segments = validvariable(tfmdata)
197--         if instances then
198--             local values
199--             for i=1,#instances do
200--                 local instance = instances[i]
201--                 if cleanname(instance.subfamily) == value then
202--                     values = instance.values
203--                     break
204--                 end
205--             end
206--             if values then
207--                 local factors = { }
208--                 for i=1,#axis do
209--                     local a = axis[i]
210--                     factors[i] = getaxisscale(segments,a.minimum,a.default,a.maximum,values[i].value)
211--                 end
212--                 tfmdata.properties.instance = {
213--                     hash    = instance,
214--                     factors = factors,
215--                 }
216--             end
217--         else
218--             report("incomplete variable data")
219--         end
220--     end
221-- end
222
223-- local function initializeaxis(tfmdata,value)
224--     if type(value) == "string" then
225--         local instances, axis, segments = validvariable(tfmdata)
226--         if instances then
227--             local values = axistofactors(value)
228--             if values then
229--                 local factors = { }
230--                 for i=1,#axis do
231--                     local a = axis[i]
232--                     local d = a.default
233--                     factors[i] = getaxisscale(segments,a.minimum,d,a.maximum,values[a.name or a.tag] or d)
234--                 end
235--                 tfmdata.properties.instance = {
236--                     hash    = cleanname(value),
237--                     factors = factors,
238--                 }
239--             end
240--         else
241--             report("incomplete variable data")
242--         end
243--     end
244-- end
245
246-- registerotffeature {
247--     name        = "instance",
248--     description = "variation instance",
249--     initializers = {
250--         node = initializeinstance,
251--         base = initializeinstance,
252--     }
253-- }
254
255-- registerotffeature {
256--     name        = "axis",
257--     description = "variation axis",
258--     initializers = {
259--         node = initializeaxis,
260--         base = initializeaxis,
261--     }
262-- }
263