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|
if not modules then modules = { } end modules ['typo-krn'] = {
version = 1.001,
comment = "companion to typo-krn.mkiv",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
-- glue is still somewhat suboptimal
-- components: better split on tounicode
--
-- maybe ignore when properties[n].injections.cursivex (or mark)
local next, type, tonumber = next, type, tonumber
local nodes = nodes
local fonts = fonts
local enableaction = nodes.tasks.enableaction
local nuts = nodes.nuts
local nodepool = nuts.pool
-- check what is used
local find_node_tail = nuts.tail
local flush_node = nuts.flush_node
local insert_node_before = nuts.insert_before
local insert_node_after = nuts.insert_after
local end_of_math = nuts.end_of_math
local use_components = nuts.use_components
local copy_node = nuts.copy
local getnext = nuts.getnext
local getprev = nuts.getprev
local getid = nuts.getid
local getfont = nuts.getfont
local getsubtype = nuts.getsubtype
local getchar = nuts.getchar
local getdisc = nuts.getdisc
local getglue = nuts.getglue
local getkern = nuts.getkern
local isglyph = nuts.isglyph
local setchar = nuts.setchar
local setfield = nuts.setfield
local getattr = nuts.getattr
local takeattr = nuts.takeattr
local setattr = nuts.setattr
local setlink = nuts.setlink
local setdisc = nuts.setdisc
local setglue = nuts.setglue
local setkern = nuts.setkern
local texsetattribute = tex.setattribute
local unsetvalue = attributes.unsetvalue
local setglue = nuts.setglue -- todo
local new_kern = nodepool.kern
local new_glue = nodepool.glue
local nodecodes = nodes.nodecodes
local kerncodes = nodes.kerncodes
local gluecodes = nodes.gluecodes
local disccodes = nodes.disccodes
local listcodes = nodes.listcodes
local glyph_code = nodecodes.glyph
local kern_code = nodecodes.kern
local disc_code = nodecodes.disc
local glue_code = nodecodes.glue
local hlist_code = nodecodes.hlist
local vlist_code = nodecodes.vlist
local math_code = nodecodes.math
local boxlist_code = listcodes.box
local unknownlist_code = listcodes.unknown
local discretionarydisc_code = disccodes.discretionary
local automaticdisc_code = disccodes.automatic
local fontkern_code = kerncodes.fontkern
local userkern_code = kerncodes.userkern
local userskip_code = gluecodes.userskip
local spaceskip_code = gluecodes.spaceskip
local xspaceskip_code = gluecodes.xspaceskip
local fonthashes = fonts.hashes
local chardata = fonthashes.characters
local quaddata = fonthashes.quads
local markdata = fonthashes.marks
local fontproperties = fonthashes.properties
local fontdescriptions = fonthashes.descriptions
local fontfeatures = fonthashes.features
local tracers = nodes.tracers
local setcolor = tracers.colors.set
local resetcolor = tracers.colors.reset
local v_max = interfaces.variables.max
local v_auto = interfaces.variables.auto
typesetters = typesetters or { }
local typesetters = typesetters
local kerns = typesetters.kerns or { }
typesetters.kerns = kerns
local report = logs.reporter("kerns")
local trace_ligatures = false trackers.register("typesetters.kerns.ligatures", function(v) trace_ligatures = v end)
local trace_ligatures_d = false trackers.register("typesetters.kerns.ligatures.detail",function(v) trace_ligatures_d = v end)
kerns.mapping = kerns.mapping or { }
kerns.factors = kerns.factors or { }
local a_kerns = attributes.private("kern")
local contextsetups = fonts.specifiers.contextsetups
storage.register("typesetters/kerns/mapping", kerns.mapping, "typesetters.kerns.mapping")
storage.register("typesetters/kerns/factors", kerns.factors, "typesetters.kerns.factors")
local mapping = kerns.mapping
local factors = kerns.factors
-- one must use liga=no and mode=base and kern=yes
-- use more helpers
-- make sure it runs after all others
-- there will be a width adaptor field in nodes so this will change
-- todo: interchar kerns / disc nodes / can be made faster
-- todo: use insert_before etc
local gluefactor = 4 -- assumes quad = .5 enspace
-- red : kept by dynamic feature
-- green : kept by static feature
-- blue : keep by goodie
function kerns.keepligature(n) -- might become default
local f = getfont(n)
local a = getattr(n,0) or 0
if trace_ligatures then
local c = getchar(n)
local d = fontdescriptions[f][c].name
if a > 0 and contextsetups[a].keepligatures == v_auto then
if trace_ligatures_d then
report("font %!font:name!, glyph %a, slot %X -> ligature %s, by %s feature %a",f,d,c,"kept","dynamic","keepligatures")
end
setcolor(n,"darkred")
return true
end
local k = fontfeatures[f].keepligatures
if k == v_auto then
if trace_ligatures_d then
report("font %!font:name!, glyph %a, slot %X -> ligature %s, by %s feature %a",f,d,c,"kept","static","keepligatures")
end
setcolor(n,"darkgreen")
return true
end
if not k then
if trace_ligatures_d then
report("font %!font:name!, glyph %a, slot %X -> ligature %s, by %s feature %a",f,d,c,"split","static","keepligatures")
end
resetcolor(n)
return false
end
local k = fontproperties[f].keptligatures
if not k then
report("font %!font:name!, glyph %a, slot %X -> ligature %s, %s goodie specification",f,d,c,"split","no")
resetcolor(n)
return false
end
if k and k[c] then
report("font %!font:name!, glyph %a, slot %X -> ligature %s, %s goodie specification",f,d,c,"kept","by")
setcolor(n,"darkblue")
return true
else
report("font %!font:name!, glyph %a, slot %X -> ligature %s, %s goodie specification",f,d,c,"split","by")
resetcolor(n)
return false
end
else
if a > 0 and contextsetups[a].keepligatures == v_auto then
return true
end
local k = fontfeatures[f].keepligatures
if k == v_auto then
return true
end
if not k then
return false
end
local k = fontproperties[f].keptligatures
if not k then
return false
end
if k and k[c] then
return true
end
end
end
-- can be optimized .. the prev thing .. but hardly worth the effort
local function kern_injector(fillup,kern)
if fillup then
local g = new_glue(kern)
setfield(g,"stretch",kern)
setfield(g,"stretch_order",1)
return g
else
return new_kern(kern)
end
end
-- a simple list injector, no components and such .. just disable ligatures in
-- kern mode .. maybe not even hyphenate ... anyway, the next one is for simple
-- sublists .. beware: we can have char -1
local function inject_begin(boundary,prev,keeptogether,krn,ok) -- prev is a glyph
local char, id = isglyph(boundary)
if id == kern_code then
if getsubtype(boundary) == fontkern_code then
local inject = true
if keeptogether then
local next = getnext(boundary)
if not next or (getid(next) == glyph_code and keeptogether(prev,next)) then
inject = false
end
end
if inject then
-- not yet ok, as injected kerns can be overlays (from node-inj.lua)
setkern(boundary,getkern(boundary) + quaddata[getfont(prev)]*krn,userkern_code)
return boundary, true
end
end
elseif char then
if keeptogether and keeptogether(boundary,prev) then
-- keep 'm
else
local prevchar = isglyph(prev)
if prevchar and prevchar > 0 then
local font = getfont(boundary)
local data = chardata[font][prevchar]
local kerns = data and data.kerns
local kern = new_kern((kerns and kerns[char] or 0) + quaddata[font]*krn)
setlink(kern,boundary)
return kern, true
end
end
end
return boundary, ok
end
local function inject_end(boundary,next,keeptogether,krn,ok)
local tail = find_node_tail(boundary)
local char, id = isglyph(tail)
if id == kern_code then
if getsubtype(tail) == fontkern_code then
local inject = true
if keeptogether then
local prev = getprev(tail)
if getid(prev) == glyph_code and keeptogether(prev,two) then
inject = false
end
end
if inject then
-- not yet ok, as injected kerns can be overlays (from node-inj.lua)
setkern(tail,getkern(tail) + quaddata[getfont(next)]*krn,userkern_code)
return boundary, true
end
end
elseif char then
if keeptogether and keeptogether(tail,two) then
-- keep 'm
else
local nextchar = isglyph(tail)
if nextchar and nextchar > 0 then
local font = getfont(tail)
local data = chardata[font][nextchar]
local kerns = data and data.kerns
local kern = (kerns and kerns[char] or 0) + quaddata[font]*krn
setlink(tail,new_kern(kern))
return boundary, true
end
end
end
return boundary, ok
end
local function process_list(head,keeptogether,krn,font,okay)
local start = head
local prev = nil
local pid = nil
local kern = 0
local mark = font and markdata[font]
while start do
local char, id = isglyph(start)
if char then
if not font then
font = id -- getfont(start)
mark = markdata[font]
kern = quaddata[font]*krn
end
if prev then
if mark[char] then
-- skip
elseif pid == kern_code then
if getsubtype(prev) == fontkern_code then
local inject = true
if keeptogether then
local prevprev = getprev(prev)
if getid(prevprev) == glyph_code and keeptogether(prevprev,start) then
inject = false
end
end
if inject then
-- not yet ok, as injected kerns can be overlays (from node-inj.lua)
setkern(prev,getkern(prev) + kern,userkern_code)
okay = true
end
end
elseif pid == glyph_code then
if keeptogether and keeptogether(prev,start) then
-- keep 'm
else
local prevchar = getchar(prev)
local data = chardata[font][prevchar]
local kerns = data and data.kerns
-- if kerns then
-- print("it happens indeed, basemode kerns not yet injected")
-- end
insert_node_before(head,start,new_kern((kerns and kerns[char] or 0) + kern))
okay = true
end
end
end
end
if start then
prev = start
pid = id
start = getnext(start)
end
end
return head, okay, prev
end
local function closest_bound(b,get)
b = get(b)
if b and getid(b) ~= glue_code then
while b do
if not getattr(b,a_kerns) then
break
else
local c, f = isglyph(b)
if c then
return b, f
else
b = get(b)
end
end
end
end
end
-- function kerns.handler(head)
-- local start = head
-- local lastfont = nil
-- local keepligature = kerns.keepligature
-- local keeptogether = kerns.keeptogether
-- local fillup = false
-- local bound = false
-- local prev = nil
-- local previd = nil
-- local prevchar = nil
-- local prevfont = nil
-- local prevmark = nil
-- while start do
-- -- fontkerns don't get the attribute but they always sit between glyphs so
-- -- are always valid bound .. disc nodes also somtimes don't get them
-- local id = getid(start)
-- local attr = takeattr(start,a_kerns)
-- if attr and attr > 0 then
-- local krn = mapping[attr]
-- if krn == v_max then
-- krn = .25
-- fillup = true
-- else
-- fillup = false
-- end
-- if not krn or krn == 0 then
-- bound = false
-- elseif id == glyph_code then
-- if keepligature and keepligature(start) then
-- -- keep 'm
-- else
-- -- we could use the subtype ligature but that's also a call
-- -- todo: check tounicode and use that information to split
-- head, start = use_components(head,start)
-- end
-- local char, font = isglyph(start)
-- local mark = markdata[font]
-- if not bound then
-- -- yet
-- elseif mark[char] then
-- -- skip
-- elseif previd == kern_code then
-- if getsubtype(prev) == fontkern_code then
-- local inject = true
-- if keeptogether then
-- if previd == glyph_code and keeptogether(prev,start) then
-- inject = false
-- end
-- end
-- if inject then
-- -- not yet ok, as injected kerns can be overlays (from node-inj.lua)
-- setkern(prev,getkern(prev) + quaddata[font]*krn,userkern_code)
-- end
-- end
-- elseif previd == glyph_code then
-- if prevfont == font then
-- if keeptogether and keeptogether(prev,start) then
-- -- keep 'm
-- else
-- local data = chardata[font][prevchar]
-- local kerns = data and data.kerns
-- local kern = (kerns and kerns[char] or 0) + quaddata[font]*krn
-- insert_node_before(head,start,kern_injector(fillup,kern))
-- end
-- else
-- insert_node_before(head,start,kern_injector(fillup,quaddata[font]*krn))
-- end
-- end
-- prev = start
-- prevchar = char
-- prevfont = font
-- prevmark = mark
-- previd = id
-- bound = true
-- elseif id == disc_code then
-- local prev, next, pglyph, nglyph -- delayed till needed
-- local subtype = getsubtype(start)
-- -- if subtype == automaticdisc_code then
-- -- -- this is kind of special, as we have already injected the
-- -- -- previous kern
-- -- local prev = getprev(start)
-- -- local pglyph = prev and getid(prev) == glyph_code
-- -- languages.expand(start,pglyph and prev)
-- -- -- we can have a different start now
-- -- elseif subtype ~= discretionarydisc_code then
-- -- prev = getprev(start)
-- -- pglyph = prev and getid(prev) == glyph_code
-- -- languages.expand(start,pglyph and prev)
-- -- end
-- local pre, post, replace = getdisc(start)
-- local indeed = false
-- if pre then
-- local okay = false
-- if not prev then
-- prev = getprev(start)
-- pglyph = prev and getid(prev) == glyph_code
-- end
-- if pglyph then
-- pre, okay = inject_begin(pre,prev,keeptogether,krn,okay)
-- end
-- pre, okay = process_list(pre,keeptogether,krn,false,okay)
-- if okay then
-- indeed = true
-- end
-- end
-- if post then
-- local okay = false
-- if not next then
-- next = getnext(start)
-- nglyph = next and getid(next) == glyph_code
-- end
-- if nglyph then
-- post, okay = inject_end(post,next,keeptogether,krn,okay)
-- end
-- post, okay = process_list(post,keeptogether,krn,false,okay)
-- if okay then
-- indeed = true
-- end
-- end
-- if replace then
-- local okay = false
-- if not prev then
-- prev = getprev(start)
-- pglyph = prev and getid(prev) == glyph_code
-- end
-- if pglyph then
-- replace, okay = inject_begin(replace,prev,keeptogether,krn,okay)
-- end
-- if not next then
-- next = getnext(start)
-- nglyph = next and getid(next) == glyph_code
-- end
-- if nglyph then
-- replace, okay = inject_end(replace,next,keeptogether,krn,okay)
-- end
-- replace, okay = process_list(replace,keeptogether,krn,false,okay)
-- if okay then
-- indeed = true
-- end
-- elseif prevfont then
-- replace = new_kern(quaddata[prevfont]*krn)
-- indeed = true
-- end
-- if indeed then
-- setdisc(start,pre,post,replace)
-- end
-- bound = false
-- elseif id == kern_code then
-- bound = getsubtype(start) == fontkern_code
-- prev = start
-- previd = id
-- elseif id == glue_code then
-- local subtype = getsubtype(start)
-- if subtype == userskip_code or subtype == xspaceskip_code or subtype == spaceskip_code then
-- local width, stretch, shrink, stretch_order, shrink_order = getglue(start)
-- if width > 0 then
-- local w = width + gluefactor * width * krn
-- stretch = stretch * w / width
-- shrink = shrink * w / width
-- if fillup then
-- stretch = 2 * stretch
-- shrink = 2 * shrink
-- stretch_order = 1
-- -- shrink_order = 1 ?
-- end
-- setglue(start,w,stretch,shrink,stretch_order,shrink_order)
-- end
-- end
-- bound = false
-- elseif id == hlist_code or id == vlist_code then
-- local subtype = getsubtype(start)
-- if subtype == unknownlist_code or subtype == boxlist_code then
-- -- special case
-- local b, f = closest_bound(start,getprev)
-- if b then
-- insert_node_before(head,start,kern_injector(fillup,quaddata[f]*krn))
-- end
-- local b, f = closest_bound(start,getnext)
-- if b then
-- insert_node_after(head,start,kern_injector(fillup,quaddata[f]*krn))
-- end
-- end
-- bound = false
-- elseif id == math_code then
-- start = end_of_math(start)
-- bound = false
-- end
-- if start then
-- start = getnext(start)
-- end
-- elseif id == kern_code then
-- bound = getsubtype(start) == fontkern_code
-- prev = start
-- previd = id
-- start = getnext(start)
-- else
-- bound = false
-- start = getnext(start)
-- end
-- end
-- return head
-- end
function kerns.handler(head)
local start = head
local lastfont = nil
local keepligature = kerns.keepligature
local keeptogether = kerns.keeptogether
local fillup = false
local bound = false
local prev = nil
local previd = nil
local prevchar = nil
local prevfont = nil
local prevmark = nil
while start do
-- fontkerns don't get the attribute but they always sit between glyphs so
-- are always valid bound .. disc nodes also sometimes don't get them
local attr = takeattr(start,a_kerns)
if attr and attr > 0 then
local char, id = isglyph(start)
local krn = mapping[attr]
if krn == v_max then
krn = .25
fillup = true
else
fillup = false
end
if not krn or krn == 0 then
bound = false
elseif char then -- id == glyph_code
local font = id -- more readable
local mark = markdata[font]
if keepligature and keepligature(start) then
-- keep 'm
else
-- head, start = use_components(head,start)
-- beware, these are not kerned so we mighty need a kern only pass
-- maybe some day .. anyway, one should disable ligaturing
local data = chardata[font][char]
if data then
local unicode = data.unicode -- can be cached
if type(unicode) == "table" then
char = unicode[1]
local s = start
setchar(s,char)
for i=2,#unicode do
local n = copy_node(s)
if i == 2 then
setattr(n,a_kerns,attr) -- we took away the attr
end
setchar(n,unicode[i])
insert_node_after(head,s,n)
s = n
end
end
end
end
if not bound then
-- yet
elseif mark[char] then
-- skip
elseif previd == kern_code then
if getsubtype(prev) == fontkern_code then
local inject = true
if keeptogether then
if previd == glyph_code and keeptogether(prev,start) then
inject = false
end
end
if inject then
-- not yet ok, as injected kerns can be overlays (from node-inj.lua)
setkern(prev,getkern(prev) + quaddata[font]*krn,userkern_code)
end
end
elseif previd == glyph_code then
if prevfont == font then
if keeptogether and keeptogether(prev,start) then
-- keep 'm
else
-- hm, only basemode ... will go away ...
local data = chardata[font][prevchar]
local kerns = data and data.kerns
local kern = (kerns and kerns[char] or 0) + quaddata[font]*krn
insert_node_before(head,start,kern_injector(fillup,kern))
end
else
insert_node_before(head,start,kern_injector(fillup,quaddata[font]*krn))
end
end
prev = start
prevchar = char
prevfont = font
prevmark = mark
previd = glyph_code -- id
bound = true
elseif id == disc_code then
local prev, next, pglyph, nglyph -- delayed till needed
local subtype = getsubtype(start)
-- if subtype == automaticdisc_code then
-- -- this is kind of special, as we have already injected the
-- -- previous kern
-- local prev = getprev(start)
-- local pglyph = prev and getid(prev) == glyph_code
-- languages.expand(start,pglyph and prev)
-- -- we can have a different start now
-- elseif subtype ~= discretionarydisc_code then
-- prev = getprev(start)
-- pglyph = prev and getid(prev) == glyph_code
-- languages.expand(start,pglyph and prev)
-- end
local pre, post, replace = getdisc(start)
local indeed = false
if pre then
local okay = false
if not prev then
prev = getprev(start)
pglyph = prev and getid(prev) == glyph_code
end
if pglyph then
pre, okay = inject_begin(pre,prev,keeptogether,krn,okay)
end
pre, okay = process_list(pre,keeptogether,krn,false,okay)
if okay then
indeed = true
end
end
if post then
local okay = false
if not next then
next = getnext(start)
nglyph = next and getid(next) == glyph_code
end
if nglyph then
post, okay = inject_end(post,next,keeptogether,krn,okay)
end
post, okay = process_list(post,keeptogether,krn,false,okay)
if okay then
indeed = true
end
end
if replace then
local okay = false
if not prev then
prev = getprev(start)
pglyph = prev and getid(prev) == glyph_code
end
if pglyph then
replace, okay = inject_begin(replace,prev,keeptogether,krn,okay)
end
if not next then
next = getnext(start)
nglyph = next and getid(next) == glyph_code
end
if nglyph then
replace, okay = inject_end(replace,next,keeptogether,krn,okay)
end
replace, okay = process_list(replace,keeptogether,krn,false,okay)
if okay then
indeed = true
end
elseif prevfont then
replace = new_kern(quaddata[prevfont]*krn)
indeed = true
end
if indeed then
setdisc(start,pre,post,replace)
end
bound = false
elseif id == kern_code then
bound = getsubtype(start) == fontkern_code
prev = start
previd = id
elseif id == glue_code then
local subtype = getsubtype(start)
if subtype == userskip_code or subtype == xspaceskip_code or subtype == spaceskip_code then
local width, stretch, shrink, stretch_order, shrink_order = getglue(start)
if width > 0 then
local w = width + gluefactor * width * krn
stretch = stretch * w / width
shrink = shrink * w / width
if fillup then
stretch = 2 * stretch
shrink = 2 * shrink
stretch_order = 1
-- shrink_order = 1 ?
end
setglue(start,w,stretch,shrink,stretch_order,shrink_order)
end
end
bound = false
elseif id == hlist_code or id == vlist_code then
local subtype = getsubtype(start)
if subtype == unknownlist_code or subtype == boxlist_code then
-- special case
local b, f = closest_bound(start,getprev)
if b then
insert_node_before(head,start,kern_injector(fillup,quaddata[f]*krn))
end
local b, f = closest_bound(start,getnext)
if b then
insert_node_after(head,start,kern_injector(fillup,quaddata[f]*krn))
end
end
bound = false
elseif id == math_code then
start = end_of_math(start)
bound = false
end
if start then
start = getnext(start)
end
else
local id = getid(start)
if id == kern_code then
bound = getsubtype(start) == fontkern_code
prev = start
previd = id
start = getnext(start)
else
bound = false
start = getnext(start)
end
end
end
return head
end
local enabled = false
function kerns.set(factor)
if factor ~= v_max then
factor = tonumber(factor) or 0
end
if factor == v_max or factor ~= 0 then
if not enabled then
enableaction("processors","typesetters.kerns.handler")
enabled = true
end
local a = factors[factor]
if not a then
a = #mapping + 1
factors[factors], mapping[a] = a, factor
end
factor = a
else
factor = unsetvalue
end
texsetattribute(a_kerns,factor)
return factor
end
-- interface
interfaces.implement {
name = "setcharacterkerning",
actions = kerns.set,
arguments = "string"
}
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