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+if not modules then modules = { } end modules ['font-otn'] = {
+ version = 1.001,
+ comment = "companion to font-ini.mkiv",
+ author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+ copyright = "PRAGMA ADE / ConTeXt Development Team",
+ license = "see context related readme files",
+}
+
+-- preprocessors = { "nodes" }
+
+-- this is still somewhat preliminary and it will get better in due time;
+-- much functionality could only be implemented thanks to the husayni font
+-- of Idris Samawi Hamid to who we dedicate this module.
+
+-- in retrospect it always looks easy but believe it or not, it took a lot
+-- of work to get proper open type support done: buggy fonts, fuzzy specs,
+-- special made testfonts, many skype sessions between taco, idris and me,
+-- torture tests etc etc ... unfortunately the code does not show how much
+-- time it took ...
+
+-- todo:
+--
+-- kerning is probably not yet ok for latin around dics nodes (interesting challenge)
+-- extension infrastructure (for usage out of context)
+-- sorting features according to vendors/renderers
+-- alternative loop quitters
+-- check cursive and r2l
+-- find out where ignore-mark-classes went
+-- default features (per language, script)
+-- handle positions (we need example fonts)
+-- handle gpos_single (we might want an extra width field in glyph nodes because adding kerns might interfere)
+-- mark (to mark) code is still not what it should be (too messy but we need some more extreem husayni tests)
+-- remove some optimizations (when I have a faster machine)
+--
+-- maybe redo the lot some way (more context specific)
+
+--[[ldx--
+<p>This module is a bit more split up that I'd like but since we also want to test
+with plain <l n='tex'/> it has to be so. This module is part of <l n='context'/>
+and discussion about improvements and functionality mostly happens on the
+<l n='context'/> mailing list.</p>
+
+<p>The specification of OpenType is kind of vague. Apart from a lack of a proper
+free specifications there's also the problem that Microsoft and Adobe
+may have their own interpretation of how and in what order to apply features.
+In general the Microsoft website has more detailed specifications and is a
+better reference. There is also some information in the FontForge help files.</p>
+
+<p>Because there is so much possible, fonts might contain bugs and/or be made to
+work with certain rederers. These may evolve over time which may have the side
+effect that suddenly fonts behave differently.</p>
+
+<p>After a lot of experiments (mostly by Taco, me and Idris) we're now at yet another
+implementation. Of course all errors are mine and of course the code can be
+improved. There are quite some optimizations going on here and processing speed
+is currently acceptable. Not all functions are implemented yet, often because I
+lack the fonts for testing. Many scripts are not yet supported either, but I will
+look into them as soon as <l n='context'/> users ask for it.</p>
+
+<p>Because there are different interpretations possible, I will extend the code
+with more (configureable) variants. I can also add hooks for users so that they can
+write their own extensions.</p>
+
+<p>Glyphs are indexed not by unicode but in their own way. This is because there is no
+relationship with unicode at all, apart from the fact that a font might cover certain
+ranges of characters. One character can have multiple shapes. However, at the
+<l n='tex'/> end we use unicode so and all extra glyphs are mapped into a private
+space. This is needed because we need to access them and <l n='tex'/> has to include
+then in the output eventually.</p>
+
+<p>The raw table as it coms from <l n='fontforge'/> gets reorganized in to fit out needs.
+In <l n='context'/> that table is packed (similar tables are shared) and cached on disk
+so that successive runs can use the optimized table (after loading the table is
+unpacked). The flattening code used later is a prelude to an even more compact table
+format (and as such it keeps evolving).</p>
+
+<p>This module is sparsely documented because it is a moving target. The table format
+of the reader changes and we experiment a lot with different methods for supporting
+features.</p>
+
+<p>As with the <l n='afm'/> code, we may decide to store more information in the
+<l n='otf'/> table.</p>
+
+<p>Incrementing the version number will force a re-cache. We jump the number by one
+when there's a fix in the <l n='fontforge'/> library or <l n='lua'/> code that
+results in different tables.</p>
+--ldx]]--
+
+-- action handler chainproc chainmore comment
+--
+-- gsub_single ok ok ok
+-- gsub_multiple ok ok not implemented yet
+-- gsub_alternate ok ok not implemented yet
+-- gsub_ligature ok ok ok
+-- gsub_context ok --
+-- gsub_contextchain ok --
+-- gsub_reversecontextchain ok --
+-- chainsub -- ok
+-- reversesub -- ok
+-- gpos_mark2base ok ok
+-- gpos_mark2ligature ok ok
+-- gpos_mark2mark ok ok
+-- gpos_cursive ok untested
+-- gpos_single ok ok
+-- gpos_pair ok ok
+-- gpos_context ok --
+-- gpos_contextchain ok --
+--
+-- todo: contextpos and contextsub and class stuff
+--
+-- actions:
+--
+-- handler : actions triggered by lookup
+-- chainproc : actions triggered by contextual lookup
+-- chainmore : multiple substitutions triggered by contextual lookup (e.g. fij -> f + ij)
+--
+-- remark: the 'not implemented yet' variants will be done when we have fonts that use them
+-- remark: we need to check what to do with discretionaries
+
+-- We used to have independent hashes for lookups but as the tags are unique
+-- we now use only one hash. If needed we can have multiple again but in that
+-- case I will probably prefix (i.e. rename) the lookups in the cached font file.
+
+-- Todo: make plugin feature that operates on char/glyphnode arrays
+
+local concat, insert, remove = table.concat, table.insert, table.remove
+local gmatch, gsub, find, match, lower, strip = string.gmatch, string.gsub, string.find, string.match, string.lower, string.strip
+local type, next, tonumber, tostring = type, next, tonumber, tostring
+local lpegmatch = lpeg.match
+local random = math.random
+local formatters = string.formatters
+
+local logs, trackers, nodes, attributes = logs, trackers, nodes, attributes
+
+local registertracker = trackers.register
+
+local fonts = fonts
+local otf = fonts.handlers.otf
+
+local trace_lookups = false registertracker("otf.lookups", function(v) trace_lookups = v end)
+local trace_singles = false registertracker("otf.singles", function(v) trace_singles = v end)
+local trace_multiples = false registertracker("otf.multiples", function(v) trace_multiples = v end)
+local trace_alternatives = false registertracker("otf.alternatives", function(v) trace_alternatives = v end)
+local trace_ligatures = false registertracker("otf.ligatures", function(v) trace_ligatures = v end)
+local trace_contexts = false registertracker("otf.contexts", function(v) trace_contexts = v end)
+local trace_marks = false registertracker("otf.marks", function(v) trace_marks = v end)
+local trace_kerns = false registertracker("otf.kerns", function(v) trace_kerns = v end)
+local trace_cursive = false registertracker("otf.cursive", function(v) trace_cursive = v end)
+local trace_preparing = false registertracker("otf.preparing", function(v) trace_preparing = v end)
+local trace_bugs = false registertracker("otf.bugs", function(v) trace_bugs = v end)
+local trace_details = false registertracker("otf.details", function(v) trace_details = v end)
+local trace_applied = false registertracker("otf.applied", function(v) trace_applied = v end)
+local trace_steps = false registertracker("otf.steps", function(v) trace_steps = v end)
+local trace_skips = false registertracker("otf.skips", function(v) trace_skips = v end)
+local trace_directions = false registertracker("otf.directions", function(v) trace_directions = v end)
+
+local report_direct = logs.reporter("fonts","otf direct")
+local report_subchain = logs.reporter("fonts","otf subchain")
+local report_chain = logs.reporter("fonts","otf chain")
+local report_process = logs.reporter("fonts","otf process")
+local report_prepare = logs.reporter("fonts","otf prepare")
+local report_warning = logs.reporter("fonts","otf warning")
+
+registertracker("otf.verbose_chain", function(v) otf.setcontextchain(v and "verbose") end)
+registertracker("otf.normal_chain", function(v) otf.setcontextchain(v and "normal") end)
+
+registertracker("otf.replacements", "otf.singles,otf.multiples,otf.alternatives,otf.ligatures")
+registertracker("otf.positions","otf.marks,otf.kerns,otf.cursive")
+registertracker("otf.actions","otf.replacements,otf.positions")
+registertracker("otf.injections","nodes.injections")
+
+registertracker("*otf.sample","otf.steps,otf.actions,otf.analyzing")
+
+local insert_node_after = node.insert_after
+local delete_node = nodes.delete
+local copy_node = node.copy
+local find_node_tail = node.tail or node.slide
+local flush_node_list = node.flush_list
+local end_of_math = node.end_of_math
+
+local setmetatableindex = table.setmetatableindex
+
+local zwnj = 0x200C
+local zwj = 0x200D
+local wildcard = "*"
+local default = "dflt"
+
+local nodecodes = nodes.nodecodes
+local whatcodes = nodes.whatcodes
+local glyphcodes = nodes.glyphcodes
+local disccodes = nodes.disccodes
+
+local glyph_code = nodecodes.glyph
+local glue_code = nodecodes.glue
+local disc_code = nodecodes.disc
+local whatsit_code = nodecodes.whatsit
+local math_code = nodecodes.math
+
+local dir_code = whatcodes.dir
+local localpar_code = whatcodes.localpar
+
+local discretionary_code = disccodes.discretionary
+
+local ligature_code = glyphcodes.ligature
+
+local privateattribute = attributes.private
+
+-- Something is messed up: we have two mark / ligature indices, one at the injection
+-- end and one here ... this is bases in KE's patches but there is something fishy
+-- there as I'm pretty sure that for husayni we need some connection (as it's much
+-- more complex than an average font) but I need proper examples of all cases, not
+-- of only some.
+
+local a_state = privateattribute('state')
+local a_markbase = privateattribute('markbase')
+local a_markmark = privateattribute('markmark')
+local a_markdone = privateattribute('markdone') -- assigned at the injection end
+local a_cursbase = privateattribute('cursbase')
+local a_curscurs = privateattribute('curscurs')
+local a_cursdone = privateattribute('cursdone')
+local a_kernpair = privateattribute('kernpair')
+local a_ligacomp = privateattribute('ligacomp') -- assigned here (ideally it should be combined)
+
+local injections = nodes.injections
+local setmark = injections.setmark
+local setcursive = injections.setcursive
+local setkern = injections.setkern
+local setpair = injections.setpair
+
+local markonce = true
+local cursonce = true
+local kernonce = true
+
+local fonthashes = fonts.hashes
+local fontdata = fonthashes.identifiers
+
+local otffeatures = fonts.constructors.newfeatures("otf")
+local registerotffeature = otffeatures.register
+
+local onetimemessage = fonts.loggers.onetimemessage or function() end
+
+otf.defaultnodealternate = "none" -- first last
+
+-- we share some vars here, after all, we have no nested lookups and less code
+
+local tfmdata = false
+local characters = false
+local descriptions = false
+local resources = false
+local marks = false
+local currentfont = false
+local lookuptable = false
+local anchorlookups = false
+local lookuptypes = false
+local handlers = { }
+local rlmode = 0
+local featurevalue = false
+
+-- head is always a whatsit so we can safely assume that head is not changed
+
+-- we use this for special testing and documentation
+
+local checkstep = (nodes and nodes.tracers and nodes.tracers.steppers.check) or function() end
+local registerstep = (nodes and nodes.tracers and nodes.tracers.steppers.register) or function() end
+local registermessage = (nodes and nodes.tracers and nodes.tracers.steppers.message) or function() end
+
+local function logprocess(...)
+ if trace_steps then
+ registermessage(...)
+ end
+ report_direct(...)
+end
+
+local function logwarning(...)
+ report_direct(...)
+end
+
+local f_unicode = formatters["%U"]
+local f_uniname = formatters["%U (%s)"]
+local f_unilist = formatters["% t (% t)"]
+
+local function gref(n) -- currently the same as in font-otb
+ if type(n) == "number" then
+ local description = descriptions[n]
+ local name = description and description.name
+ if name then
+ return f_uniname(n,name)
+ else
+ return f_unicode(n)
+ end
+ elseif n then
+ local num, nam = { }, { }
+ for i=1,#n do
+ local ni = n[i]
+ if tonumber(ni) then -- later we will start at 2
+ local di = descriptions[ni]
+ num[i] = f_unicode(ni)
+ nam[i] = di and di.name or "-"
+ end
+ end
+ return f_unilist(num,nam)
+ else
+ return "<error in node mode tracing>"
+ end
+end
+
+local function cref(kind,chainname,chainlookupname,lookupname,index) -- not in the mood to alias f_
+ if index then
+ return formatters["feature %a, chain %a, sub %a, lookup %a, index %a"](kind,chainname,chainlookupname,lookupname,index)
+ elseif lookupname then
+ return formatters["feature %a, chain %a, sub %a, lookup %a"](kind,chainname,chainlookupname,lookupname)
+ elseif chainlookupname then
+ return formatters["feature %a, chain %a, sub %a"](kind,chainname,chainlookupname)
+ elseif chainname then
+ return formatters["feature %a, chain %a"](kind,chainname)
+ else
+ return formatters["feature %a"](kind)
+ end
+end
+
+local function pref(kind,lookupname)
+ return formatters["feature %a, lookup %a"](kind,lookupname)
+end
+
+-- We can assume that languages that use marks are not hyphenated. We can also assume
+-- that at most one discretionary is present.
+
+-- We do need components in funny kerning mode but maybe I can better reconstruct then
+-- as we do have the font components info available; removing components makes the
+-- previous code much simpler. Also, later on copying and freeing becomes easier.
+-- However, for arabic we need to keep them around for the sake of mark placement
+-- and indices.
+
+local function copy_glyph(g) -- next and prev are untouched !
+ local components = g.components
+ if components then
+ g.components = nil
+ local n = copy_node(g)
+ g.components = components
+ return n
+ else
+ return copy_node(g)
+ end
+end
+
+-- start is a mark and we need to keep that one
+
+local function markstoligature(kind,lookupname,head,start,stop,char)
+ if start == stop and start.char == char then
+ return head, start
+ else
+ local prev = start.prev
+ local next = stop.next
+ start.prev = nil
+ stop.next = nil
+ local base = copy_glyph(start)
+ if head == start then
+ head = base
+ end
+ base.char = char
+ base.subtype = ligature_code
+ base.components = start
+ if prev then
+ prev.next = base
+ end
+ if next then
+ next.prev = base
+ end
+ base.next = next
+ base.prev = prev
+ return head, base
+ end
+end
+
+-- The next code is somewhat complicated by the fact that some fonts can have ligatures made
+-- from ligatures that themselves have marks. This was identified by Kai in for instance
+-- arabtype: KAF LAM SHADDA ALEF FATHA (0x0643 0x0644 0x0651 0x0627 0x064E). This becomes
+-- KAF LAM-ALEF with a SHADDA on the first and a FATHA op de second component. In a next
+-- iteration this becomes a KAF-LAM-ALEF with a SHADDA on the second and a FATHA on the
+-- third component.
+
+local function getcomponentindex(start)
+ if start.id ~= glyph_code then
+ return 0
+ elseif start.subtype == ligature_code then
+ local i = 0
+ local components = start.components
+ while components do
+ i = i + getcomponentindex(components)
+ components = components.next
+ end
+ return i
+ elseif not marks[start.char] then
+ return 1
+ else
+ return 0
+ end
+end
+
+-- eventually we will do positioning in an other way (needs addional w/h/d fields)
+
+local function toligature(kind,lookupname,head,start,stop,char,markflag,discfound) -- brr head
+ if start == stop and start.char == char then
+ start.char = char
+ return head, start
+ end
+ local prev = start.prev
+ local next = stop.next
+ start.prev = nil
+ stop.next = nil
+ local base = copy_glyph(start)
+ if start == head then
+ head = base
+ end
+ base.char = char
+ base.subtype = ligature_code
+ base.components = start -- start can have components
+ if prev then
+ prev.next = base
+ end
+ if next then
+ next.prev = base
+ end
+ base.next = next
+ base.prev = prev
+ if not discfound then
+ local deletemarks = markflag ~= "mark"
+ local components = start
+ local baseindex = 0
+ local componentindex = 0
+ local head = base
+ local current = base
+ -- first we loop over the glyphs in start .. stop
+ while start do
+ local char = start.char
+ if not marks[char] then
+ baseindex = baseindex + componentindex
+ componentindex = getcomponentindex(start)
+ elseif not deletemarks then -- quite fishy
+ start[a_ligacomp] = baseindex + (start[a_ligacomp] or componentindex)
+ if trace_marks then
+ logwarning("%s: keep mark %s, gets index %s",pref(kind,lookupname),gref(char),start[a_ligacomp])
+ end
+ head, current = insert_node_after(head,current,copy_node(start)) -- unlikely that mark has components
+ elseif trace_marks then
+ logwarning("%s: delete mark %s",pref(kind,lookupname),gref(char))
+ end
+ start = start.next
+ end
+ -- we can have one accent as part of a lookup and another following
+ -- local start = components -- was wrong (component scanning was introduced when more complex ligs in devanagari was added)
+ local start = current.next
+ while start and start.id == glyph_code do
+ local char = start.char
+ if marks[char] then
+ start[a_ligacomp] = baseindex + (start[a_ligacomp] or componentindex)
+ if trace_marks then
+ logwarning("%s: set mark %s, gets index %s",pref(kind,lookupname),gref(char),start[a_ligacomp])
+ end
+ else
+ break
+ end
+ start = start.next
+ end
+ end
+ return head, base
+end
+
+function handlers.gsub_single(head,start,kind,lookupname,replacement)
+ if trace_singles then
+ logprocess("%s: replacing %s by single %s",pref(kind,lookupname),gref(start.char),gref(replacement))
+ end
+ start.char = replacement
+ return head, start, true
+end
+
+local function get_alternative_glyph(start,alternatives,value,trace_alternatives)
+ local n = #alternatives
+ if value == "random" then
+ local r = random(1,n)
+ return alternatives[r], trace_alternatives and formatters["value %a, taking %a"](value,r)
+ elseif value == "first" then
+ return alternatives[1], trace_alternatives and formatters["value %a, taking %a"](value,1)
+ elseif value == "last" then
+ return alternatives[n], trace_alternatives and formatters["value %a, taking %a"](value,n)
+ else
+ value = tonumber(value)
+ if type(value) ~= "number" then
+ return alternatives[1], trace_alternatives and formatters["invalid value %s, taking %a"](value,1)
+ elseif value > n then
+ local defaultalt = otf.defaultnodealternate
+ if defaultalt == "first" then
+ return alternatives[n], trace_alternatives and formatters["invalid value %s, taking %a"](value,1)
+ elseif defaultalt == "last" then
+ return alternatives[1], trace_alternatives and formatters["invalid value %s, taking %a"](value,n)
+ else
+ return false, trace_alternatives and formatters["invalid value %a, %s"](value,"out of range")
+ end
+ elseif value == 0 then
+ return start.char, trace_alternatives and formatters["invalid value %a, %s"](value,"no change")
+ elseif value < 1 then
+ return alternatives[1], trace_alternatives and formatters["invalid value %a, taking %a"](value,1)
+ else
+ return alternatives[value], trace_alternatives and formatters["value %a, taking %a"](value,value)
+ end
+ end
+end
+
+local function multiple_glyphs(head,start,multiple,ignoremarks)
+ local nofmultiples = #multiple
+ if nofmultiples > 0 then
+ start.char = multiple[1]
+ if nofmultiples > 1 then
+ local sn = start.next
+ for k=2,nofmultiples do -- todo: use insert_node
+-- untested:
+--
+-- while ignoremarks and marks[sn.char] then
+-- local sn = sn.next
+-- end
+ local n = copy_node(start) -- ignore components
+ n.char = multiple[k]
+ n.next = sn
+ n.prev = start
+ if sn then
+ sn.prev = n
+ end
+ start.next = n
+ start = n
+ end
+ end
+ return head, start, true
+ else
+ if trace_multiples then
+ logprocess("no multiple for %s",gref(start.char))
+ end
+ return head, start, false
+ end
+end
+
+function handlers.gsub_alternate(head,start,kind,lookupname,alternative,sequence)
+ local value = featurevalue == true and tfmdata.shared.features[kind] or featurevalue
+ local choice, comment = get_alternative_glyph(start,alternative,value,trace_alternatives)
+ if choice then
+ if trace_alternatives then
+ logprocess("%s: replacing %s by alternative %a to %s, %s",pref(kind,lookupname),gref(start.char),choice,gref(choice),comment)
+ end
+ start.char = choice
+ else
+ if trace_alternatives then
+ logwarning("%s: no variant %a for %s, %s",pref(kind,lookupname),value,gref(start.char),comment)
+ end
+ end
+ return head, start, true
+end
+
+function handlers.gsub_multiple(head,start,kind,lookupname,multiple,sequence)
+ if trace_multiples then
+ logprocess("%s: replacing %s by multiple %s",pref(kind,lookupname),gref(start.char),gref(multiple))
+ end
+ return multiple_glyphs(head,start,multiple,sequence.flags[1])
+end
+
+function handlers.gsub_ligature(head,start,kind,lookupname,ligature,sequence)
+ local s, stop, discfound = start.next, nil, false
+ local startchar = start.char
+ if marks[startchar] then
+ while s do
+ local id = s.id
+ if id == glyph_code and s.font == currentfont and s.subtype<256 then
+ local lg = ligature[s.char]
+ if lg then
+ stop = s
+ ligature = lg
+ s = s.next
+ else
+ break
+ end
+ else
+ break
+ end
+ end
+ if stop then
+ local lig = ligature.ligature
+ if lig then
+ if trace_ligatures then
+ local stopchar = stop.char
+ head, start = markstoligature(kind,lookupname,head,start,stop,lig)
+ logprocess("%s: replacing %s upto %s by ligature %s case 1",pref(kind,lookupname),gref(startchar),gref(stopchar),gref(start.char))
+ else
+ head, start = markstoligature(kind,lookupname,head,start,stop,lig)
+ end
+ return head, start, true
+ else
+ -- ok, goto next lookup
+ end
+ end
+ else
+ local skipmark = sequence.flags[1]
+ while s do
+ local id = s.id
+ if id == glyph_code and s.subtype<256 then
+ if s.font == currentfont then
+ local char = s.char
+ if skipmark and marks[char] then
+ s = s.next
+ else
+ local lg = ligature[char]
+ if lg then
+ stop = s
+ ligature = lg
+ s = s.next
+ else
+ break
+ end
+ end
+ else
+ break
+ end
+ elseif id == disc_code then
+ discfound = true
+ s = s.next
+ else
+ break
+ end
+ end
+ local lig = ligature.ligature
+ if lig then
+ if stop then
+ if trace_ligatures then
+ local stopchar = stop.char
+ head, start = toligature(kind,lookupname,head,start,stop,lig,skipmark,discfound)
+ logprocess("%s: replacing %s upto %s by ligature %s case 2",pref(kind,lookupname),gref(startchar),gref(stopchar),gref(start.char))
+ else
+ head, start = toligature(kind,lookupname,head,start,stop,lig,skipmark,discfound)
+ end
+ return head, start, true
+ else
+ -- weird but happens (in some arabic font)
+ start.char = lig
+ if trace_ligatures then
+ logprocess("%s: replacing %s by (no real) ligature %s case 3",pref(kind,lookupname),gref(startchar),gref(lig))
+ end
+ return head, start, true
+ end
+ else
+ -- weird but happens
+ end
+ end
+ return head, start, false
+end
+
+--[[ldx--
+<p>We get hits on a mark, but we're not sure if the it has to be applied so
+we need to explicitly test for basechar, baselig and basemark entries.</p>
+--ldx]]--
+
+function handlers.gpos_mark2base(head,start,kind,lookupname,markanchors,sequence)
+ local markchar = start.char
+ if marks[markchar] then
+ local base = start.prev -- [glyph] [start=mark]
+ if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+ local basechar = base.char
+ if marks[basechar] then
+ while true do
+ base = base.prev
+ if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+ basechar = base.char
+ if not marks[basechar] then
+ break
+ end
+ else
+ if trace_bugs then
+ logwarning("%s: no base for mark %s",pref(kind,lookupname),gref(markchar))
+ end
+ return head, start, false
+ end
+ end
+ end
+ local baseanchors = descriptions[basechar]
+ if baseanchors then
+ baseanchors = baseanchors.anchors
+ end
+ if baseanchors then
+ local baseanchors = baseanchors['basechar']
+ if baseanchors then
+ local al = anchorlookups[lookupname]
+ for anchor,ba in next, baseanchors do
+ if al[anchor] then
+ local ma = markanchors[anchor]
+ if ma then
+ local dx, dy, bound = setmark(start,base,tfmdata.parameters.factor,rlmode,ba,ma)
+ if trace_marks then
+ logprocess("%s, anchor %s, bound %s: anchoring mark %s to basechar %s => (%p,%p)",
+ pref(kind,lookupname),anchor,bound,gref(markchar),gref(basechar),dx,dy)
+ end
+ return head, start, true
+ end
+ end
+ end
+ if trace_bugs then
+ logwarning("%s, no matching anchors for mark %s and base %s",pref(kind,lookupname),gref(markchar),gref(basechar))
+ end
+ end
+ elseif trace_bugs then
+ -- logwarning("%s: char %s is missing in font",pref(kind,lookupname),gref(basechar))
+ onetimemessage(currentfont,basechar,"no base anchors",report_fonts)
+ end
+ elseif trace_bugs then
+ logwarning("%s: prev node is no char",pref(kind,lookupname))
+ end
+ elseif trace_bugs then
+ logwarning("%s: mark %s is no mark",pref(kind,lookupname),gref(markchar))
+ end
+ return head, start, false
+end
+
+function handlers.gpos_mark2ligature(head,start,kind,lookupname,markanchors,sequence)
+ -- check chainpos variant
+ local markchar = start.char
+ if marks[markchar] then
+ local base = start.prev -- [glyph] [optional marks] [start=mark]
+ if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+ local basechar = base.char
+ if marks[basechar] then
+ while true do
+ base = base.prev
+ if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+ basechar = base.char
+ if not marks[basechar] then
+ break
+ end
+ else
+ if trace_bugs then
+ logwarning("%s: no base for mark %s",pref(kind,lookupname),gref(markchar))
+ end
+ return head, start, false
+ end
+ end
+ end
+ local index = start[a_ligacomp]
+ local baseanchors = descriptions[basechar]
+ if baseanchors then
+ baseanchors = baseanchors.anchors
+ if baseanchors then
+ local baseanchors = baseanchors['baselig']
+ if baseanchors then
+ local al = anchorlookups[lookupname]
+ for anchor, ba in next, baseanchors do
+ if al[anchor] then
+ local ma = markanchors[anchor]
+ if ma then
+ ba = ba[index]
+ if ba then
+ local dx, dy, bound = setmark(start,base,tfmdata.parameters.factor,rlmode,ba,ma) -- index
+ if trace_marks then
+ logprocess("%s, anchor %s, index %s, bound %s: anchoring mark %s to baselig %s at index %s => (%p,%p)",
+ pref(kind,lookupname),anchor,index,bound,gref(markchar),gref(basechar),index,dx,dy)
+ end
+ return head, start, true
+ else
+ if trace_bugs then
+ logwarning("%s: no matching anchors for mark %s and baselig %s with index %a",pref(kind,lookupname),gref(markchar),gref(basechar),index)
+ end
+ end
+ end
+ end
+ end
+ if trace_bugs then
+ logwarning("%s: no matching anchors for mark %s and baselig %s",pref(kind,lookupname),gref(markchar),gref(basechar))
+ end
+ end
+ end
+ elseif trace_bugs then
+ -- logwarning("%s: char %s is missing in font",pref(kind,lookupname),gref(basechar))
+ onetimemessage(currentfont,basechar,"no base anchors",report_fonts)
+ end
+ elseif trace_bugs then
+ logwarning("%s: prev node is no char",pref(kind,lookupname))
+ end
+ elseif trace_bugs then
+ logwarning("%s: mark %s is no mark",pref(kind,lookupname),gref(markchar))
+ end
+ return head, start, false
+end
+
+function handlers.gpos_mark2mark(head,start,kind,lookupname,markanchors,sequence)
+ local markchar = start.char
+ if marks[markchar] then
+ local base = start.prev -- [glyph] [basemark] [start=mark]
+ local slc = start[a_ligacomp]
+ if slc then -- a rather messy loop ... needs checking with husayni
+ while base do
+ local blc = base[a_ligacomp]
+ if blc and blc ~= slc then
+ base = base.prev
+ else
+ break
+ end
+ end
+ end
+ if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then -- subtype test can go
+ local basechar = base.char
+ local baseanchors = descriptions[basechar]
+ if baseanchors then
+ baseanchors = baseanchors.anchors
+ if baseanchors then
+ baseanchors = baseanchors['basemark']
+ if baseanchors then
+ local al = anchorlookups[lookupname]
+ for anchor,ba in next, baseanchors do
+ if al[anchor] then
+ local ma = markanchors[anchor]
+ if ma then
+ local dx, dy, bound = setmark(start,base,tfmdata.parameters.factor,rlmode,ba,ma,true)
+ if trace_marks then
+ logprocess("%s, anchor %s, bound %s: anchoring mark %s to basemark %s => (%p,%p)",
+ pref(kind,lookupname),anchor,bound,gref(markchar),gref(basechar),dx,dy)
+ end
+ return head, start, true
+ end
+ end
+ end
+ if trace_bugs then
+ logwarning("%s: no matching anchors for mark %s and basemark %s",pref(kind,lookupname),gref(markchar),gref(basechar))
+ end
+ end
+ end
+ elseif trace_bugs then
+ -- logwarning("%s: char %s is missing in font",pref(kind,lookupname),gref(basechar))
+ onetimemessage(currentfont,basechar,"no base anchors",report_fonts)
+ end
+ elseif trace_bugs then
+ logwarning("%s: prev node is no mark",pref(kind,lookupname))
+ end
+ elseif trace_bugs then
+ logwarning("%s: mark %s is no mark",pref(kind,lookupname),gref(markchar))
+ end
+ return head, start, false
+end
+
+function handlers.gpos_cursive(head,start,kind,lookupname,exitanchors,sequence) -- to be checked
+ local alreadydone = cursonce and start[a_cursbase]
+ if not alreadydone then
+ local done = false
+ local startchar = start.char
+ if marks[startchar] then
+ if trace_cursive then
+ logprocess("%s: ignoring cursive for mark %s",pref(kind,lookupname),gref(startchar))
+ end
+ else
+ local nxt = start.next
+ while not done and nxt and nxt.id == glyph_code and nxt.font == currentfont and nxt.subtype<256 do
+ local nextchar = nxt.char
+ if marks[nextchar] then
+ -- should not happen (maybe warning)
+ nxt = nxt.next
+ else
+ local entryanchors = descriptions[nextchar]
+ if entryanchors then
+ entryanchors = entryanchors.anchors
+ if entryanchors then
+ entryanchors = entryanchors['centry']
+ if entryanchors then
+ local al = anchorlookups[lookupname]
+ for anchor, entry in next, entryanchors do
+ if al[anchor] then
+ local exit = exitanchors[anchor]
+ if exit then
+ local dx, dy, bound = setcursive(start,nxt,tfmdata.parameters.factor,rlmode,exit,entry,characters[startchar],characters[nextchar])
+ if trace_cursive then
+ logprocess("%s: moving %s to %s cursive (%p,%p) using anchor %s and bound %s in rlmode %s",pref(kind,lookupname),gref(startchar),gref(nextchar),dx,dy,anchor,bound,rlmode)
+ end
+ done = true
+ break
+ end
+ end
+ end
+ end
+ end
+ elseif trace_bugs then
+ -- logwarning("%s: char %s is missing in font",pref(kind,lookupname),gref(startchar))
+ onetimemessage(currentfont,startchar,"no entry anchors",report_fonts)
+ end
+ break
+ end
+ end
+ end
+ return head, start, done
+ else
+ if trace_cursive and trace_details then
+ logprocess("%s, cursive %s is already done",pref(kind,lookupname),gref(start.char),alreadydone)
+ end
+ return head, start, false
+ end
+end
+
+function handlers.gpos_single(head,start,kind,lookupname,kerns,sequence)
+ local startchar = start.char
+ local dx, dy, w, h = setpair(start,tfmdata.parameters.factor,rlmode,sequence.flags[4],kerns,characters[startchar])
+ if trace_kerns then
+ logprocess("%s: shifting single %s by (%p,%p) and correction (%p,%p)",pref(kind,lookupname),gref(startchar),dx,dy,w,h)
+ end
+ return head, start, false
+end
+
+function handlers.gpos_pair(head,start,kind,lookupname,kerns,sequence)
+ -- todo: kerns in disc nodes: pre, post, replace -> loop over disc too
+ -- todo: kerns in components of ligatures
+ local snext = start.next
+ if not snext then
+ return head, start, false
+ else
+ local prev, done = start, false
+ local factor = tfmdata.parameters.factor
+ local lookuptype = lookuptypes[lookupname]
+ while snext and snext.id == glyph_code and snext.font == currentfont and snext.subtype<256 do
+ local nextchar = snext.char
+ local krn = kerns[nextchar]
+ if not krn and marks[nextchar] then
+ prev = snext
+ snext = snext.next
+ else
+ if not krn then
+ -- skip
+ elseif type(krn) == "table" then
+ if lookuptype == "pair" then -- probably not needed
+ local a, b = krn[2], krn[3]
+ if a and #a > 0 then
+ local startchar = start.char
+ local x, y, w, h = setpair(start,factor,rlmode,sequence.flags[4],a,characters[startchar])
+ if trace_kerns then
+ logprocess("%s: shifting first of pair %s and %s by (%p,%p) and correction (%p,%p)",pref(kind,lookupname),gref(startchar),gref(nextchar),x,y,w,h)
+ end
+ end
+ if b and #b > 0 then
+ local startchar = start.char
+ local x, y, w, h = setpair(snext,factor,rlmode,sequence.flags[4],b,characters[nextchar])
+ if trace_kerns then
+ logprocess("%s: shifting second of pair %s and %s by (%p,%p) and correction (%p,%p)",pref(kind,lookupname),gref(startchar),gref(nextchar),x,y,w,h)
+ end
+ end
+ else -- wrong ... position has different entries
+ report_process("%s: check this out (old kern stuff)",pref(kind,lookupname))
+ -- local a, b = krn[2], krn[6]
+ -- if a and a ~= 0 then
+ -- local k = setkern(snext,factor,rlmode,a)
+ -- if trace_kerns then
+ -- logprocess("%s: inserting first kern %s between %s and %s",pref(kind,lookupname),k,gref(prev.char),gref(nextchar))
+ -- end
+ -- end
+ -- if b and b ~= 0 then
+ -- logwarning("%s: ignoring second kern xoff %s",pref(kind,lookupname),b*factor)
+ -- end
+ end
+ done = true
+ elseif krn ~= 0 then
+ local k = setkern(snext,factor,rlmode,krn)
+ if trace_kerns then
+ logprocess("%s: inserting kern %s between %s and %s",pref(kind,lookupname),k,gref(prev.char),gref(nextchar))
+ end
+ done = true
+ end
+ break
+ end
+ end
+ return head, start, done
+ end
+end
+
+--[[ldx--
+<p>I will implement multiple chain replacements once I run into a font that uses
+it. It's not that complex to handle.</p>
+--ldx]]--
+
+local chainmores = { }
+local chainprocs = { }
+
+local function logprocess(...)
+ if trace_steps then
+ registermessage(...)
+ end
+ report_subchain(...)
+end
+
+local logwarning = report_subchain
+
+local function logprocess(...)
+ if trace_steps then
+ registermessage(...)
+ end
+ report_chain(...)
+end
+
+local logwarning = report_chain
+
+-- We could share functions but that would lead to extra function calls with many
+-- arguments, redundant tests and confusing messages.
+
+function chainprocs.chainsub(head,start,stop,kind,chainname,currentcontext,lookuphash,lookuplist,chainlookupname)
+ logwarning("%s: a direct call to chainsub cannot happen",cref(kind,chainname,chainlookupname))
+ return head, start, false
+end
+
+function chainmores.chainsub(head,start,stop,kind,chainname,currentcontext,lookuphash,lookuplist,chainlookupname,n)
+ logprocess("%s: a direct call to chainsub cannot happen",cref(kind,chainname,chainlookupname))
+ return head, start, false
+end
+
+-- The reversesub is a special case, which is why we need to store the replacements
+-- in a bit weird way. There is no lookup and the replacement comes from the lookup
+-- itself. It is meant mostly for dealing with Urdu.
+
+function chainprocs.reversesub(head,start,stop,kind,chainname,currentcontext,lookuphash,replacements)
+ local char = start.char
+ local replacement = replacements[char]
+ if replacement then
+ if trace_singles then
+ logprocess("%s: single reverse replacement of %s by %s",cref(kind,chainname),gref(char),gref(replacement))
+ end
+ start.char = replacement
+ return head, start, true
+ else
+ return head, start, false
+ end
+end
+
+--[[ldx--
+<p>This chain stuff is somewhat tricky since we can have a sequence of actions to be
+applied: single, alternate, multiple or ligature where ligature can be an invalid
+one in the sense that it will replace multiple by one but not neccessary one that
+looks like the combination (i.e. it is the counterpart of multiple then). For
+example, the following is valid:</p>
+
+<typing>
+<line>xxxabcdexxx [single a->A][multiple b->BCD][ligature cde->E] xxxABCDExxx</line>
+</typing>
+
+<p>Therefore we we don't really do the replacement here already unless we have the
+single lookup case. The efficiency of the replacements can be improved by deleting
+as less as needed but that would also make the code even more messy.</p>
+--ldx]]--
+
+-- local function delete_till_stop(head,start,stop,ignoremarks) -- keeps start
+-- local n = 1
+-- if start == stop then
+-- -- done
+-- elseif ignoremarks then
+-- repeat -- start x x m x x stop => start m
+-- local next = start.next
+-- if not marks[next.char] then
+-- local components = next.components
+-- if components then -- probably not needed
+-- flush_node_list(components)
+-- end
+-- head = delete_node(head,next)
+-- end
+-- n = n + 1
+-- until next == stop
+-- else -- start x x x stop => start
+-- repeat
+-- local next = start.next
+-- local components = next.components
+-- if components then -- probably not needed
+-- flush_node_list(components)
+-- end
+-- head = delete_node(head,next)
+-- n = n + 1
+-- until next == stop
+-- end
+-- return head, n
+-- end
+
+--[[ldx--
+<p>Here we replace start by a single variant, First we delete the rest of the
+match.</p>
+--ldx]]--
+
+function chainprocs.gsub_single(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname,chainindex)
+ -- todo: marks ?
+ local current = start
+ local subtables = currentlookup.subtables
+ if #subtables > 1 then
+ logwarning("todo: check if we need to loop over the replacements: %s",concat(subtables," "))
+ end
+ while current do
+ if current.id == glyph_code then
+ local currentchar = current.char
+ local lookupname = subtables[1] -- only 1
+ local replacement = lookuphash[lookupname]
+ if not replacement then
+ if trace_bugs then
+ logwarning("%s: no single hits",cref(kind,chainname,chainlookupname,lookupname,chainindex))
+ end
+ else
+ replacement = replacement[currentchar]
+ if not replacement or replacement == "" then
+ if trace_bugs then
+ logwarning("%s: no single for %s",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(currentchar))
+ end
+ else
+ if trace_singles then
+ logprocess("%s: replacing single %s by %s",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(currentchar),gref(replacement))
+ end
+ current.char = replacement
+ end
+ end
+ return head, start, true
+ elseif current == stop then
+ break
+ else
+ current = current.next
+ end
+ end
+ return head, start, false
+end
+
+chainmores.gsub_single = chainprocs.gsub_single
+
+--[[ldx--
+<p>Here we replace start by a sequence of new glyphs. First we delete the rest of
+the match.</p>
+--ldx]]--
+
+function chainprocs.gsub_multiple(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
+ -- local head, n = delete_till_stop(head,start,stop)
+ local startchar = start.char
+ local subtables = currentlookup.subtables
+ local lookupname = subtables[1]
+ local replacements = lookuphash[lookupname]
+ if not replacements then
+ if trace_bugs then
+ logwarning("%s: no multiple hits",cref(kind,chainname,chainlookupname,lookupname))
+ end
+ else
+ replacements = replacements[startchar]
+ if not replacements or replacement == "" then
+ if trace_bugs then
+ logwarning("%s: no multiple for %s",cref(kind,chainname,chainlookupname,lookupname),gref(startchar))
+ end
+ else
+ if trace_multiples then
+ logprocess("%s: replacing %s by multiple characters %s",cref(kind,chainname,chainlookupname,lookupname),gref(startchar),gref(replacements))
+ end
+ return multiple_glyphs(head,start,replacements,currentlookup.flags[1])
+ end
+ end
+ return head, start, false
+end
+
+chainmores.gsub_multiple = chainprocs.gsub_multiple
+
+--[[ldx--
+<p>Here we replace start by new glyph. First we delete the rest of the match.</p>
+--ldx]]--
+
+-- char_1 mark_1 -> char_x mark_1 (ignore marks)
+-- char_1 mark_1 -> char_x
+
+-- to be checked: do we always have just one glyph?
+-- we can also have alternates for marks
+-- marks come last anyway
+-- are there cases where we need to delete the mark
+
+function chainprocs.gsub_alternate(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
+ local current = start
+ local subtables = currentlookup.subtables
+ local value = featurevalue == true and tfmdata.shared.features[kind] or featurevalue
+ while current do
+ if current.id == glyph_code then -- is this check needed?
+ local currentchar = current.char
+ local lookupname = subtables[1]
+ local alternatives = lookuphash[lookupname]
+ if not alternatives then
+ if trace_bugs then
+ logwarning("%s: no alternative hit",cref(kind,chainname,chainlookupname,lookupname))
+ end
+ else
+ alternatives = alternatives[currentchar]
+ if alternatives then
+ local choice, comment = get_alternative_glyph(current,alternatives,value,trace_alternatives)
+ if choice then
+ if trace_alternatives then
+ logprocess("%s: replacing %s by alternative %a to %s, %s",cref(kind,chainname,chainlookupname,lookupname),gref(char),choice,gref(choice),comment)
+ end
+ start.char = choice
+ else
+ if trace_alternatives then
+ logwarning("%s: no variant %a for %s, %s",cref(kind,chainname,chainlookupname,lookupname),value,gref(char),comment)
+ end
+ end
+ elseif trace_bugs then
+ logwarning("%s: no alternative for %s, %s",cref(kind,chainname,chainlookupname,lookupname),gref(currentchar),comment)
+ end
+ end
+ return head, start, true
+ elseif current == stop then
+ break
+ else
+ current = current.next
+ end
+ end
+ return head, start, false
+end
+
+chainmores.gsub_alternate = chainprocs.gsub_alternate
+
+--[[ldx--
+<p>When we replace ligatures we use a helper that handles the marks. I might change
+this function (move code inline and handle the marks by a separate function). We
+assume rather stupid ligatures (no complex disc nodes).</p>
+--ldx]]--
+
+function chainprocs.gsub_ligature(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname,chainindex)
+ local startchar = start.char
+ local subtables = currentlookup.subtables
+ local lookupname = subtables[1]
+ local ligatures = lookuphash[lookupname]
+ if not ligatures then
+ if trace_bugs then
+ logwarning("%s: no ligature hits",cref(kind,chainname,chainlookupname,lookupname,chainindex))
+ end
+ else
+ ligatures = ligatures[startchar]
+ if not ligatures then
+ if trace_bugs then
+ logwarning("%s: no ligatures starting with %s",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar))
+ end
+ else
+ local s = start.next
+ local discfound = false
+ local last = stop
+ local nofreplacements = 0
+ local skipmark = currentlookup.flags[1]
+ while s do
+ local id = s.id
+ if id == disc_code then
+ s = s.next
+ discfound = true
+ else
+ local schar = s.char
+ if skipmark and marks[schar] then -- marks
+ s = s.next
+ else
+ local lg = ligatures[schar]
+ if lg then
+ ligatures, last, nofreplacements = lg, s, nofreplacements + 1
+ if s == stop then
+ break
+ else
+ s = s.next
+ end
+ else
+ break
+ end
+ end
+ end
+ end
+ local l2 = ligatures.ligature
+ if l2 then
+ if chainindex then
+ stop = last
+ end
+ if trace_ligatures then
+ if start == stop then
+ logprocess("%s: replacing character %s by ligature %s case 3",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar),gref(l2))
+ else
+ logprocess("%s: replacing character %s upto %s by ligature %s case 4",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar),gref(stop.char),gref(l2))
+ end
+ end
+ head, start = toligature(kind,lookupname,head,start,stop,l2,currentlookup.flags[1],discfound)
+ return head, start, true, nofreplacements
+ elseif trace_bugs then
+ if start == stop then
+ logwarning("%s: replacing character %s by ligature fails",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar))
+ else
+ logwarning("%s: replacing character %s upto %s by ligature fails",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar),gref(stop.char))
+ end
+ end
+ end
+ end
+ return head, start, false, 0
+end
+
+chainmores.gsub_ligature = chainprocs.gsub_ligature
+
+function chainprocs.gpos_mark2base(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
+ local markchar = start.char
+ if marks[markchar] then
+ local subtables = currentlookup.subtables
+ local lookupname = subtables[1]
+ local markanchors = lookuphash[lookupname]
+ if markanchors then
+ markanchors = markanchors[markchar]
+ end
+ if markanchors then
+ local base = start.prev -- [glyph] [start=mark]
+ if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+ local basechar = base.char
+ if marks[basechar] then
+ while true do
+ base = base.prev
+ if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+ basechar = base.char
+ if not marks[basechar] then
+ break
+ end
+ else
+ if trace_bugs then
+ logwarning("%s: no base for mark %s",pref(kind,lookupname),gref(markchar))
+ end
+ return head, start, false
+ end
+ end
+ end
+ local baseanchors = descriptions[basechar].anchors
+ if baseanchors then
+ local baseanchors = baseanchors['basechar']
+ if baseanchors then
+ local al = anchorlookups[lookupname]
+ for anchor,ba in next, baseanchors do
+ if al[anchor] then
+ local ma = markanchors[anchor]
+ if ma then
+ local dx, dy, bound = setmark(start,base,tfmdata.parameters.factor,rlmode,ba,ma)
+ if trace_marks then
+ logprocess("%s, anchor %s, bound %s: anchoring mark %s to basechar %s => (%p,%p)",
+ cref(kind,chainname,chainlookupname,lookupname),anchor,bound,gref(markchar),gref(basechar),dx,dy)
+ end
+ return head, start, true
+ end
+ end
+ end
+ if trace_bugs then
+ logwarning("%s, no matching anchors for mark %s and base %s",cref(kind,chainname,chainlookupname,lookupname),gref(markchar),gref(basechar))
+ end
+ end
+ end
+ elseif trace_bugs then
+ logwarning("%s: prev node is no char",cref(kind,chainname,chainlookupname,lookupname))
+ end
+ elseif trace_bugs then
+ logwarning("%s: mark %s has no anchors",cref(kind,chainname,chainlookupname,lookupname),gref(markchar))
+ end
+ elseif trace_bugs then
+ logwarning("%s: mark %s is no mark",cref(kind,chainname,chainlookupname),gref(markchar))
+ end
+ return head, start, false
+end
+
+function chainprocs.gpos_mark2ligature(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
+ local markchar = start.char
+ if marks[markchar] then
+ local subtables = currentlookup.subtables
+ local lookupname = subtables[1]
+ local markanchors = lookuphash[lookupname]
+ if markanchors then
+ markanchors = markanchors[markchar]
+ end
+ if markanchors then
+ local base = start.prev -- [glyph] [optional marks] [start=mark]
+ if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+ local basechar = base.char
+ if marks[basechar] then
+ while true do
+ base = base.prev
+ if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+ basechar = base.char
+ if not marks[basechar] then
+ break
+ end
+ else
+ if trace_bugs then
+ logwarning("%s: no base for mark %s",cref(kind,chainname,chainlookupname,lookupname),markchar)
+ end
+ return head, start, false
+ end
+ end
+ end
+ -- todo: like marks a ligatures hash
+ local index = start[a_ligacomp]
+ local baseanchors = descriptions[basechar].anchors
+ if baseanchors then
+ local baseanchors = baseanchors['baselig']
+ if baseanchors then
+ local al = anchorlookups[lookupname]
+ for anchor,ba in next, baseanchors do
+ if al[anchor] then
+ local ma = markanchors[anchor]
+ if ma then
+ ba = ba[index]
+ if ba then
+ local dx, dy, bound = setmark(start,base,tfmdata.parameters.factor,rlmode,ba,ma) -- index
+ if trace_marks then
+ logprocess("%s, anchor %s, bound %s: anchoring mark %s to baselig %s at index %s => (%p,%p)",
+ cref(kind,chainname,chainlookupname,lookupname),anchor,a or bound,gref(markchar),gref(basechar),index,dx,dy)
+ end
+ return head, start, true
+ end
+ end
+ end
+ end
+ if trace_bugs then
+ logwarning("%s: no matching anchors for mark %s and baselig %s",cref(kind,chainname,chainlookupname,lookupname),gref(markchar),gref(basechar))
+ end
+ end
+ end
+ elseif trace_bugs then
+ logwarning("feature %s, lookup %s: prev node is no char",kind,lookupname)
+ end
+ elseif trace_bugs then
+ logwarning("%s: mark %s has no anchors",cref(kind,chainname,chainlookupname,lookupname),gref(markchar))
+ end
+ elseif trace_bugs then
+ logwarning("%s: mark %s is no mark",cref(kind,chainname,chainlookupname),gref(markchar))
+ end
+ return head, start, false
+end
+
+function chainprocs.gpos_mark2mark(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
+ local markchar = start.char
+ if marks[markchar] then
+ -- local alreadydone = markonce and start[a_markmark]
+ -- if not alreadydone then
+ -- local markanchors = descriptions[markchar].anchors markanchors = markanchors and markanchors.mark
+ local subtables = currentlookup.subtables
+ local lookupname = subtables[1]
+ local markanchors = lookuphash[lookupname]
+ if markanchors then
+ markanchors = markanchors[markchar]
+ end
+ if markanchors then
+ local base = start.prev -- [glyph] [basemark] [start=mark]
+ local slc = start[a_ligacomp]
+ if slc then -- a rather messy loop ... needs checking with husayni
+ while base do
+ local blc = base[a_ligacomp]
+ if blc and blc ~= slc then
+ base = base.prev
+ else
+ break
+ end
+ end
+ end
+ if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then -- subtype test can go
+ local basechar = base.char
+ local baseanchors = descriptions[basechar].anchors
+ if baseanchors then
+ baseanchors = baseanchors['basemark']
+ if baseanchors then
+ local al = anchorlookups[lookupname]
+ for anchor,ba in next, baseanchors do
+ if al[anchor] then
+ local ma = markanchors[anchor]
+ if ma then
+ local dx, dy, bound = setmark(start,base,tfmdata.parameters.factor,rlmode,ba,ma,true)
+ if trace_marks then
+ logprocess("%s, anchor %s, bound %s: anchoring mark %s to basemark %s => (%p,%p)",
+ cref(kind,chainname,chainlookupname,lookupname),anchor,bound,gref(markchar),gref(basechar),dx,dy)
+ end
+ return head, start, true
+ end
+ end
+ end
+ if trace_bugs then
+ logwarning("%s: no matching anchors for mark %s and basemark %s",gref(kind,chainname,chainlookupname,lookupname),gref(markchar),gref(basechar))
+ end
+ end
+ end
+ elseif trace_bugs then
+ logwarning("%s: prev node is no mark",cref(kind,chainname,chainlookupname,lookupname))
+ end
+ elseif trace_bugs then
+ logwarning("%s: mark %s has no anchors",cref(kind,chainname,chainlookupname,lookupname),gref(markchar))
+ end
+ -- elseif trace_marks and trace_details then
+ -- logprocess("%s, mark %s is already bound (n=%s), ignoring mark2mark",pref(kind,lookupname),gref(markchar),alreadydone)
+ -- end
+ elseif trace_bugs then
+ logwarning("%s: mark %s is no mark",cref(kind,chainname,chainlookupname),gref(markchar))
+ end
+ return head, start, false
+end
+
+function chainprocs.gpos_cursive(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
+ local alreadydone = cursonce and start[a_cursbase]
+ if not alreadydone then
+ local startchar = start.char
+ local subtables = currentlookup.subtables
+ local lookupname = subtables[1]
+ local exitanchors = lookuphash[lookupname]
+ if exitanchors then
+ exitanchors = exitanchors[startchar]
+ end
+ if exitanchors then
+ local done = false
+ if marks[startchar] then
+ if trace_cursive then
+ logprocess("%s: ignoring cursive for mark %s",pref(kind,lookupname),gref(startchar))
+ end
+ else
+ local nxt = start.next
+ while not done and nxt and nxt.id == glyph_code and nxt.font == currentfont and nxt.subtype<256 do
+ local nextchar = nxt.char
+ if marks[nextchar] then
+ -- should not happen (maybe warning)
+ nxt = nxt.next
+ else
+ local entryanchors = descriptions[nextchar]
+ if entryanchors then
+ entryanchors = entryanchors.anchors
+ if entryanchors then
+ entryanchors = entryanchors['centry']
+ if entryanchors then
+ local al = anchorlookups[lookupname]
+ for anchor, entry in next, entryanchors do
+ if al[anchor] then
+ local exit = exitanchors[anchor]
+ if exit then
+ local dx, dy, bound = setcursive(start,nxt,tfmdata.parameters.factor,rlmode,exit,entry,characters[startchar],characters[nextchar])
+ if trace_cursive then
+ logprocess("%s: moving %s to %s cursive (%p,%p) using anchor %s and bound %s in rlmode %s",pref(kind,lookupname),gref(startchar),gref(nextchar),dx,dy,anchor,bound,rlmode)
+ end
+ done = true
+ break
+ end
+ end
+ end
+ end
+ end
+ elseif trace_bugs then
+ -- logwarning("%s: char %s is missing in font",pref(kind,lookupname),gref(startchar))
+ onetimemessage(currentfont,startchar,"no entry anchors",report_fonts)
+ end
+ break
+ end
+ end
+ end
+ return head, start, done
+ else
+ if trace_cursive and trace_details then
+ logprocess("%s, cursive %s is already done",pref(kind,lookupname),gref(start.char),alreadydone)
+ end
+ return head, start, false
+ end
+ end
+ return head, start, false
+end
+
+function chainprocs.gpos_single(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname,chainindex,sequence)
+ -- untested .. needs checking for the new model
+ local startchar = start.char
+ local subtables = currentlookup.subtables
+ local lookupname = subtables[1]
+ local kerns = lookuphash[lookupname]
+ if kerns then
+ kerns = kerns[startchar] -- needed ?
+ if kerns then
+ local dx, dy, w, h = setpair(start,tfmdata.parameters.factor,rlmode,sequence.flags[4],kerns,characters[startchar])
+ if trace_kerns then
+ logprocess("%s: shifting single %s by (%p,%p) and correction (%p,%p)",cref(kind,chainname,chainlookupname),gref(startchar),dx,dy,w,h)
+ end
+ end
+ end
+ return head, start, false
+end
+
+chainmores.gpos_single = chainprocs.gpos_single -- okay?
+
+-- when machines become faster i will make a shared function
+
+function chainprocs.gpos_pair(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname,chainindex,sequence)
+ local snext = start.next
+ if snext then
+ local startchar = start.char
+ local subtables = currentlookup.subtables
+ local lookupname = subtables[1]
+ local kerns = lookuphash[lookupname]
+ if kerns then
+ kerns = kerns[startchar]
+ if kerns then
+ local lookuptype = lookuptypes[lookupname]
+ local prev, done = start, false
+ local factor = tfmdata.parameters.factor
+ while snext and snext.id == glyph_code and snext.font == currentfont and snext.subtype<256 do
+ local nextchar = snext.char
+ local krn = kerns[nextchar]
+ if not krn and marks[nextchar] then
+ prev = snext
+ snext = snext.next
+ else
+ if not krn then
+ -- skip
+ elseif type(krn) == "table" then
+ if lookuptype == "pair" then
+ local a, b = krn[2], krn[3]
+ if a and #a > 0 then
+ local startchar = start.char
+ local x, y, w, h = setpair(start,factor,rlmode,sequence.flags[4],a,characters[startchar])
+ if trace_kerns then
+ logprocess("%s: shifting first of pair %s and %s by (%p,%p) and correction (%p,%p)",cref(kind,chainname,chainlookupname),gref(startchar),gref(nextchar),x,y,w,h)
+ end
+ end
+ if b and #b > 0 then
+ local startchar = start.char
+ local x, y, w, h = setpair(snext,factor,rlmode,sequence.flags[4],b,characters[nextchar])
+ if trace_kerns then
+ logprocess("%s: shifting second of pair %s and %s by (%p,%p) and correction (%p,%p)",cref(kind,chainname,chainlookupname),gref(startchar),gref(nextchar),x,y,w,h)
+ end
+ end
+ else
+ report_process("%s: check this out (old kern stuff)",cref(kind,chainname,chainlookupname))
+ local a, b = krn[2], krn[6]
+ if a and a ~= 0 then
+ local k = setkern(snext,factor,rlmode,a)
+ if trace_kerns then
+ logprocess("%s: inserting first kern %s between %s and %s",cref(kind,chainname,chainlookupname),k,gref(prev.char),gref(nextchar))
+ end
+ end
+ if b and b ~= 0 then
+ logwarning("%s: ignoring second kern xoff %s",cref(kind,chainname,chainlookupname),b*factor)
+ end
+ end
+ done = true
+ elseif krn ~= 0 then
+ local k = setkern(snext,factor,rlmode,krn)
+ if trace_kerns then
+ logprocess("%s: inserting kern %s between %s and %s",cref(kind,chainname,chainlookupname),k,gref(prev.char),gref(nextchar))
+ end
+ done = true
+ end
+ break
+ end
+ end
+ return head, start, done
+ end
+ end
+ end
+ return head, start, false
+end
+
+chainmores.gpos_pair = chainprocs.gpos_pair -- okay?
+
+-- what pointer to return, spec says stop
+-- to be discussed ... is bidi changer a space?
+-- elseif char == zwnj and sequence[n][32] then -- brrr
+
+-- somehow l or f is global
+-- we don't need to pass the currentcontext, saves a bit
+-- make a slow variant then can be activated but with more tracing
+
+local function show_skip(kind,chainname,char,ck,class)
+ if ck[9] then
+ logwarning("%s: skipping char %s, class %a, rule %a, lookuptype %a, %a => %a",cref(kind,chainname),gref(char),class,ck[1],ck[2],ck[9],ck[10])
+ else
+ logwarning("%s: skipping char %s, class %a, rule %a, lookuptype %a",cref(kind,chainname),gref(char),class,ck[1],ck[2])
+ end
+end
+
+local function normal_handle_contextchain(head,start,kind,chainname,contexts,sequence,lookuphash)
+ -- local rule, lookuptype, sequence, f, l, lookups = ck[1], ck[2] ,ck[3], ck[4], ck[5], ck[6]
+ local flags = sequence.flags
+ local done = false
+ local skipmark = flags[1]
+ local skipligature = flags[2]
+ local skipbase = flags[3]
+ local someskip = skipmark or skipligature or skipbase -- could be stored in flags for a fast test (hm, flags could be false !)
+ local markclass = sequence.markclass -- todo, first we need a proper test
+ local skipped = false
+ for k=1,#contexts do
+ local match = true
+ local current = start
+ local last = start
+ local ck = contexts[k]
+ local seq = ck[3]
+ local s = #seq
+ -- f..l = mid string
+ if s == 1 then
+ -- never happens
+ match = current.id == glyph_code and current.font == currentfont and current.subtype<256 and seq[1][current.char]
+ else
+ -- maybe we need a better space check (maybe check for glue or category or combination)
+ -- we cannot optimize for n=2 because there can be disc nodes
+ local f, l = ck[4], ck[5]
+ -- current match
+ if f == 1 and f == l then -- current only
+ -- already a hit
+ -- match = true
+ else -- before/current/after | before/current | current/after
+ -- no need to test first hit (to be optimized)
+ if f == l then -- new, else last out of sync (f is > 1)
+ -- match = true
+ else
+ local n = f + 1
+ last = last.next
+ while n <= l do
+ if last then
+ local id = last.id
+ if id == glyph_code then
+ if last.font == currentfont and last.subtype<256 then
+ local char = last.char
+ local ccd = descriptions[char]
+ if ccd then
+ local class = ccd.class
+ if class == skipmark or class == skipligature or class == skipbase or (markclass and class == "mark" and not markclass[char]) then
+ skipped = true
+ if trace_skips then
+ show_skip(kind,chainname,char,ck,class)
+ end
+ last = last.next
+ elseif seq[n][char] then
+ if n < l then
+ last = last.next
+ end
+ n = n + 1
+ else
+ match = false
+ break
+ end
+ else
+ match = false
+ break
+ end
+ else
+ match = false
+ break
+ end
+ elseif id == disc_code then
+ last = last.next
+ else
+ match = false
+ break
+ end
+ else
+ match = false
+ break
+ end
+ end
+ end
+ end
+ -- before
+ if match and f > 1 then
+ local prev = start.prev
+ if prev then
+ local n = f-1
+ while n >= 1 do
+ if prev then
+ local id = prev.id
+ if id == glyph_code then
+ if prev.font == currentfont and prev.subtype<256 then -- normal char
+ local char = prev.char
+ local ccd = descriptions[char]
+ if ccd then
+ local class = ccd.class
+ if class == skipmark or class == skipligature or class == skipbase or (markclass and class == "mark" and not markclass[char]) then
+ skipped = true
+ if trace_skips then
+ show_skip(kind,chainname,char,ck,class)
+ end
+ elseif seq[n][char] then
+ n = n -1
+ else
+ match = false
+ break
+ end
+ else
+ match = false
+ break
+ end
+ else
+ match = false
+ break
+ end
+ elseif id == disc_code then
+ -- skip 'm
+ elseif seq[n][32] then
+ n = n -1
+ else
+ match = false
+ break
+ end
+ prev = prev.prev
+ elseif seq[n][32] then -- somewhat special, as zapfino can have many preceding spaces
+ n = n -1
+ else
+ match = false
+ break
+ end
+ end
+ elseif f == 2 then
+ match = seq[1][32]
+ else
+ for n=f-1,1 do
+ if not seq[n][32] then
+ match = false
+ break
+ end
+ end
+ end
+ end
+ -- after
+ if match and s > l then
+ local current = last and last.next
+ if current then
+ -- removed optimization for s-l == 1, we have to deal with marks anyway
+ local n = l + 1
+ while n <= s do
+ if current then
+ local id = current.id
+ if id == glyph_code then
+ if current.font == currentfont and current.subtype<256 then -- normal char
+ local char = current.char
+ local ccd = descriptions[char]
+ if ccd then
+ local class = ccd.class
+ if class == skipmark or class == skipligature or class == skipbase or (markclass and class == "mark" and not markclass[char]) then
+ skipped = true
+ if trace_skips then
+ show_skip(kind,chainname,char,ck,class)
+ end
+ elseif seq[n][char] then
+ n = n + 1
+ else
+ match = false
+ break
+ end
+ else
+ match = false
+ break
+ end
+ else
+ match = false
+ break
+ end
+ elseif id == disc_code then
+ -- skip 'm
+ elseif seq[n][32] then -- brrr
+ n = n + 1
+ else
+ match = false
+ break
+ end
+ current = current.next
+ elseif seq[n][32] then
+ n = n + 1
+ else
+ match = false
+ break
+ end
+ end
+ elseif s-l == 1 then
+ match = seq[s][32]
+ else
+ for n=l+1,s do
+ if not seq[n][32] then
+ match = false
+ break
+ end
+ end
+ end
+ end
+ end
+ if match then
+ -- ck == currentcontext
+ if trace_contexts then
+ local rule, lookuptype, f, l = ck[1], ck[2], ck[4], ck[5]
+ local char = start.char
+ if ck[9] then
+ logwarning("%s: rule %s matches at char %s for (%s,%s,%s) chars, lookuptype %a, %a => %a",
+ cref(kind,chainname),rule,gref(char),f-1,l-f+1,s-l,lookuptype,ck[9],ck[10])
+ else
+ logwarning("%s: rule %s matches at char %s for (%s,%s,%s) chars, lookuptype %a",
+ cref(kind,chainname),rule,gref(char),f-1,l-f+1,s-l,lookuptype)
+ end
+ end
+ local chainlookups = ck[6]
+ if chainlookups then
+ local nofchainlookups = #chainlookups
+ -- we can speed this up if needed
+ if nofchainlookups == 1 then
+ local chainlookupname = chainlookups[1]
+ local chainlookup = lookuptable[chainlookupname]
+ if chainlookup then
+ local cp = chainprocs[chainlookup.type]
+ if cp then
+ local ok
+ head, start, ok = cp(head,start,last,kind,chainname,ck,lookuphash,chainlookup,chainlookupname,nil,sequence)
+ if ok then
+ done = true
+ end
+ else
+ logprocess("%s: %s is not yet supported",cref(kind,chainname,chainlookupname),chainlookup.type)
+ end
+ else -- shouldn't happen
+ logprocess("%s is not yet supported",cref(kind,chainname,chainlookupname))
+ end
+ else
+ local i = 1
+ repeat
+ if skipped then
+ while true do
+ local char = start.char
+ local ccd = descriptions[char]
+ if ccd then
+ local class = ccd.class
+ if class == skipmark or class == skipligature or class == skipbase or (markclass and class == "mark" and not markclass[char]) then
+ start = start.next
+ else
+ break
+ end
+ else
+ break
+ end
+ end
+ end
+ local chainlookupname = chainlookups[i]
+ local chainlookup = lookuptable[chainlookupname]
+ if not chainlookup then
+ -- okay, n matches, < n replacements
+ i = i + 1
+ else
+ local cp = chainmores[chainlookup.type]
+ if not cp then
+ -- actually an error
+ logprocess("%s: %s is not yet supported",cref(kind,chainname,chainlookupname),chainlookup.type)
+ i = i + 1
+ else
+ local ok, n
+ head, start, ok, n = cp(head,start,last,kind,chainname,ck,lookuphash,chainlookup,chainlookupname,i,sequence)
+ -- messy since last can be changed !
+ if ok then
+ done = true
+ -- skip next one(s) if ligature
+ i = i + (n or 1)
+ else
+ i = i + 1
+ end
+ end
+ end
+ if start then
+ start = start.next
+ else
+ -- weird
+ end
+ until i > nofchainlookups
+ end
+ else
+ local replacements = ck[7]
+ if replacements then
+ head, start, done = chainprocs.reversesub(head,start,last,kind,chainname,ck,lookuphash,replacements) -- sequence
+ else
+ done = true -- can be meant to be skipped
+ if trace_contexts then
+ logprocess("%s: skipping match",cref(kind,chainname))
+ end
+ end
+ end
+ end
+ end
+ return head, start, done
+end
+
+-- Because we want to keep this elsewhere (an because speed is less an issue) we
+-- pass the font id so that the verbose variant can access the relevant helper tables.
+
+local verbose_handle_contextchain = function(font,...)
+ logwarning("no verbose handler installed, reverting to 'normal'")
+ otf.setcontextchain()
+ return normal_handle_contextchain(...)
+end
+
+otf.chainhandlers = {
+ normal = normal_handle_contextchain,
+ verbose = verbose_handle_contextchain,
+}
+
+function otf.setcontextchain(method)
+ if not method or method == "normal" or not otf.chainhandlers[method] then
+ if handlers.contextchain then -- no need for a message while making the format
+ logwarning("installing normal contextchain handler")
+ end
+ handlers.contextchain = normal_handle_contextchain
+ else
+ logwarning("installing contextchain handler %a",method)
+ local handler = otf.chainhandlers[method]
+ handlers.contextchain = function(...)
+ return handler(currentfont,...) -- hm, get rid of ...
+ end
+ end
+ handlers.gsub_context = handlers.contextchain
+ handlers.gsub_contextchain = handlers.contextchain
+ handlers.gsub_reversecontextchain = handlers.contextchain
+ handlers.gpos_contextchain = handlers.contextchain
+ handlers.gpos_context = handlers.contextchain
+end
+
+otf.setcontextchain()
+
+local missing = { } -- we only report once
+
+local function logprocess(...)
+ if trace_steps then
+ registermessage(...)
+ end
+ report_process(...)
+end
+
+local logwarning = report_process
+
+local function report_missing_cache(typ,lookup)
+ local f = missing[currentfont] if not f then f = { } missing[currentfont] = f end
+ local t = f[typ] if not t then t = { } f[typ] = t end
+ if not t[lookup] then
+ t[lookup] = true
+ logwarning("missing cache for lookup %a, type %a, font %a, name %a",lookup,typ,currentfont,tfmdata.properties.fullname)
+ end
+end
+
+local resolved = { } -- we only resolve a font,script,language pair once
+
+-- todo: pass all these 'locals' in a table
+
+local lookuphashes = { }
+
+setmetatableindex(lookuphashes, function(t,font)
+ local lookuphash = fontdata[font].resources.lookuphash
+ if not lookuphash or not next(lookuphash) then
+ lookuphash = false
+ end
+ t[font] = lookuphash
+ return lookuphash
+end)
+
+-- fonts.hashes.lookups = lookuphashes
+
+local autofeatures = fonts.analyzers.features -- was: constants
+
+local function initialize(sequence,script,language,enabled)
+ local features = sequence.features
+ if features then
+ for kind, scripts in next, features do
+ local valid = enabled[kind]
+ if valid then
+ local languages = scripts[script] or scripts[wildcard]
+ if languages and (languages[language] or languages[wildcard]) then
+ return { valid, autofeatures[kind] or false, sequence.chain or 0, kind, sequence }
+ end
+ end
+ end
+ end
+ return false
+end
+
+function otf.dataset(tfmdata,font) -- generic variant, overloaded in context
+ local shared = tfmdata.shared
+ local properties = tfmdata.properties
+ local language = properties.language or "dflt"
+ local script = properties.script or "dflt"
+ local enabled = shared.features
+ local res = resolved[font]
+ if not res then
+ res = { }
+ resolved[font] = res
+ end
+ local rs = res[script]
+ if not rs then
+ rs = { }
+ res[script] = rs
+ end
+ local rl = rs[language]
+ if not rl then
+ rl = {
+ -- indexed but we can also add specific data by key
+ }
+ rs[language] = rl
+ local sequences = tfmdata.resources.sequences
+-- setmetatableindex(rl, function(t,k)
+-- if type(k) == "number" then
+-- local v = enabled and initialize(sequences[k],script,language,enabled)
+-- t[k] = v
+-- return v
+-- end
+-- end)
+for s=1,#sequences do
+ local v = enabled and initialize(sequences[s],script,language,enabled)
+ if v then
+ rl[#rl+1] = v
+ end
+end
+ end
+ return rl
+end
+
+-- elseif id == glue_code then
+-- if p[5] then -- chain
+-- local pc = pp[32]
+-- if pc then
+-- start, ok = start, false -- p[1](start,kind,p[2],pc,p[3],p[4])
+-- if ok then
+-- done = true
+-- end
+-- if start then start = start.next end
+-- else
+-- start = start.next
+-- end
+-- else
+-- start = start.next
+-- end
+
+-- there will be a new direction parser (pre-parsed etc)
+
+-- less bytecode: 290 -> 254
+--
+-- attr = attr or false
+--
+-- local a = getattr(start,0)
+-- if (a == attr and (not attribute or getattr(start,a_state) == attribute)) or (not attribute or getattr(start,a_state) == attribute) then
+-- -- the action
+-- end
+
+local function featuresprocessor(head,font,attr)
+
+ local lookuphash = lookuphashes[font] -- we can also check sequences here
+
+ if not lookuphash then
+ return head, false
+ end
+
+ if trace_steps then
+ checkstep(head)
+ end
+
+ tfmdata = fontdata[font]
+ descriptions = tfmdata.descriptions
+ characters = tfmdata.characters
+ resources = tfmdata.resources
+
+ marks = resources.marks
+ anchorlookups = resources.lookup_to_anchor
+ lookuptable = resources.lookups
+ lookuptypes = resources.lookuptypes
+
+ currentfont = font
+ rlmode = 0
+
+ local sequences = resources.sequences
+ local done = false
+ local datasets = otf.dataset(tfmdata,font,attr)
+
+ local dirstack = { } -- could move outside function
+
+ -- We could work on sub start-stop ranges instead but I wonder if there is that
+ -- much speed gain (experiments showed that it made not much sense) and we need
+ -- to keep track of directions anyway. Also at some point I want to play with
+ -- font interactions and then we do need the full sweeps.
+
+ -- Keeping track of the headnode is needed for devanagari (I generalized it a bit
+ -- so that multiple cases are also covered.)
+
+ for s=1,#datasets do
+ local dataset = datasets[s]
+ featurevalue = dataset[1] -- todo: pass to function instead of using a global
+
+ local sequence = dataset[5] -- sequences[s] -- also dataset[5]
+ local rlparmode = 0
+ local topstack = 0
+ local success = false
+ local attribute = dataset[2]
+ local chain = dataset[3] -- sequence.chain or 0
+ local typ = sequence.type
+ local subtables = sequence.subtables
+ if chain < 0 then
+ -- this is a limited case, no special treatments like 'init' etc
+ local handler = handlers[typ]
+ -- we need to get rid of this slide! probably no longer needed in latest luatex
+ local start = find_node_tail(head) -- slow (we can store tail because there's always a skip at the end): todo
+ while start do
+ local id = start.id
+ if id == glyph_code then
+ if start.font == font and start.subtype<256 then
+ local a = start[0]
+ if a then
+ a = a == attr
+ else
+ a = true
+ end
+ if a then
+ for i=1,#subtables do
+ local lookupname = subtables[i]
+ local lookupcache = lookuphash[lookupname]
+ if lookupcache then
+ local lookupmatch = lookupcache[start.char]
+ if lookupmatch then
+ head, start, success = handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
+ if success then
+ break
+ end
+ end
+ else
+ report_missing_cache(typ,lookupname)
+ end
+ end
+ if start then start = start.prev end
+ else
+ start = start.prev
+ end
+ else
+ start = start.prev
+ end
+ else
+ start = start.prev
+ end
+ end
+ else
+ local handler = handlers[typ]
+ local ns = #subtables
+ local start = head -- local ?
+ rlmode = 0 -- to be checked ?
+ if ns == 1 then -- happens often
+ local lookupname = subtables[1]
+ local lookupcache = lookuphash[lookupname]
+ if not lookupcache then -- also check for empty cache
+ report_missing_cache(typ,lookupname)
+ else
+
+ local function subrun(start)
+ -- mostly for gsub, gpos would demand a more clever approach
+ local head = start
+ local done = false
+ while start do
+ local id = start.id
+ if id == glyph_code and start.font == font and start.subtype <256 then
+ local a = start[0]
+ if a then
+ a = (a == attr) and (not attribute or start[a_state] == attribute)
+ else
+ a = not attribute or start[a_state] == attribute
+ end
+ if a then
+ local lookupmatch = lookupcache[start.char]
+ if lookupmatch then
+ -- sequence kan weg
+ local ok
+ head, start, ok = handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,1)
+ if ok then
+ done = true
+ end
+ end
+ if start then start = start.next end
+ else
+ start = start.next
+ end
+ else
+ start = start.next
+ end
+ end
+ if done then
+ success = true
+ return head
+ end
+ end
+
+ local function kerndisc(disc) -- we can assume that prev and next are glyphs
+ local prev = disc.prev
+ local next = disc.next
+ if prev and next then
+ prev.next = next
+ -- next.prev = prev
+ local a = prev[0]
+ if a then
+ a = (a == attr) and (not attribute or prev[a_state] == attribute)
+ else
+ a = not attribute or prev[a_state] == attribute
+ end
+ if a then
+ local lookupmatch = lookupcache[prev.char]
+ if lookupmatch then
+ -- sequence kan weg
+ local h, d, ok = handler(head,prev,dataset[4],lookupname,lookupmatch,sequence,lookuphash,1)
+ if ok then
+ done = true
+ success = true
+ end
+ end
+ end
+ prev.next = disc
+ -- next.prev = disc
+ end
+ return next
+ end
+
+ while start do
+ local id = start.id
+ if id == glyph_code then
+ if start.font == font and start.subtype<256 then
+ local a = start[0]
+ if a then
+ a = (a == attr) and (not attribute or start[a_state] == attribute)
+ else
+ a = not attribute or start[a_state] == attribute
+ end
+ if a then
+ local lookupmatch = lookupcache[start.char]
+ if lookupmatch then
+ -- sequence kan weg
+ local ok
+ head, start, ok = handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,1)
+ if ok then
+ success = true
+ end
+ end
+ if start then start = start.next end
+ else
+ start = start.next
+ end
+ else
+ start = start.next
+ end
+ elseif id == disc_code then
+ -- mostly for gsub
+ if start.subtype == discretionary_code then
+ local pre = start.pre
+ if pre then
+ local new = subrun(pre)
+ if new then start.pre = new end
+ end
+ local post = start.post
+ if post then
+ local new = subrun(post)
+ if new then start.post = new end
+ end
+ local replace = start.replace
+ if replace then
+ local new = subrun(replace)
+ if new then start.replace = new end
+ end
+elseif typ == "gpos_single" or typ == "gpos_pair" then
+ kerndisc(start)
+ end
+ start = start.next
+ elseif id == whatsit_code then -- will be function
+ local subtype = start.subtype
+ if subtype == dir_code then
+ local dir = start.dir
+ if dir == "+TRT" or dir == "+TLT" then
+ topstack = topstack + 1
+ dirstack[topstack] = dir
+ elseif dir == "-TRT" or dir == "-TLT" then
+ topstack = topstack - 1
+ end
+ local newdir = dirstack[topstack]
+ if newdir == "+TRT" then
+ rlmode = -1
+ elseif newdir == "+TLT" then
+ rlmode = 1
+ else
+ rlmode = rlparmode
+ end
+ if trace_directions then
+ report_process("directions after txtdir %a: parmode %a, txtmode %a, # stack %a, new dir %a",dir,rlparmode,rlmode,topstack,newdir)
+ end
+ elseif subtype == localpar_code then
+ local dir = start.dir
+ if dir == "TRT" then
+ rlparmode = -1
+ elseif dir == "TLT" then
+ rlparmode = 1
+ else
+ rlparmode = 0
+ end
+ -- one might wonder if the par dir should be looked at, so we might as well drop the next line
+ rlmode = rlparmode
+ if trace_directions then
+ report_process("directions after pardir %a: parmode %a, txtmode %a",dir,rlparmode,rlmode)
+ end
+ end
+ start = start.next
+ elseif id == math_code then
+ start = end_of_math(start).next
+ else
+ start = start.next
+ end
+ end
+ end
+ else
+
+ local function subrun(start)
+ -- mostly for gsub, gpos would demand a more clever approach
+ local head = start
+ local done = false
+ while start do
+ local id = start.id
+ if id == glyph_code and start.id == font and start.subtype <256 then
+ local a = start[0]
+ if a then
+ a = (a == attr) and (not attribute or start[a_state] == attribute)
+ else
+ a = not attribute or start[a_state] == attribute
+ end
+ if a then
+ for i=1,ns do
+ local lookupname = subtables[i]
+ local lookupcache = lookuphash[lookupname]
+ if lookupcache then
+ local lookupmatch = lookupcache[start.char]
+ if lookupmatch then
+ -- we could move all code inline but that makes things even more unreadable
+ local ok
+ head, start, ok = handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
+ if ok then
+ done = true
+ break
+ elseif not start then
+ -- don't ask why ... shouldn't happen
+ break
+ end
+ end
+ else
+ report_missing_cache(typ,lookupname)
+ end
+ end
+ if start then start = start.next end
+ else
+ start = start.next
+ end
+ else
+ start = start.next
+ end
+ end
+ if done then
+ success = true
+ return head
+ end
+ end
+
+ local function kerndisc(disc) -- we can assume that prev and next are glyphs
+ local prev = disc.prev
+ local next = disc.next
+ if prev and next then
+ prev.next = next
+ -- next.prev = prev
+ local a = prev[0]
+ if a then
+ a = (a == attr) and (not attribute or prev[a_state] == attribute)
+ else
+ a = not attribute or prev[a_state] == attribute
+ end
+ if a then
+ for i=1,ns do
+ local lookupname = subtables[i]
+ local lookupcache = lookuphash[lookupname]
+ if lookupcache then
+ local lookupmatch = lookupcache[prev.char]
+ if lookupmatch then
+ -- we could move all code inline but that makes things even more unreadable
+ local h, d, ok = handler(head,prev,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
+ if ok then
+ done = true
+ break
+ end
+ end
+ else
+ report_missing_cache(typ,lookupname)
+ end
+ end
+ end
+ prev.next = disc
+ -- next.prev = disc
+ end
+ return next
+ end
+
+ while start do
+ local id = start.id
+ if id == glyph_code then
+ if start.font == font and start.subtype<256 then
+ local a = start[0]
+ if a then
+ a = (a == attr) and (not attribute or start[a_state] == attribute)
+ else
+ a = not attribute or start[a_state] == attribute
+ end
+ if a then
+ for i=1,ns do
+ local lookupname = subtables[i]
+ local lookupcache = lookuphash[lookupname]
+ if lookupcache then
+ local lookupmatch = lookupcache[start.char]
+ if lookupmatch then
+ -- we could move all code inline but that makes things even more unreadable
+ local ok
+ head, start, ok = handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
+ if ok then
+ success = true
+ break
+ elseif not start then
+ -- don't ask why ... shouldn't happen
+ break
+ end
+ end
+ else
+ report_missing_cache(typ,lookupname)
+ end
+ end
+ if start then start = start.next end
+ else
+ start = start.next
+ end
+ else
+ start = start.next
+ end
+ elseif id == disc_code then
+ -- mostly for gsub
+ if start.subtype == discretionary_code then
+ local pre = start.pre
+ if pre then
+ local new = subrun(pre)
+ if new then start.pre = new end
+ end
+ local post = start.post
+ if post then
+ local new = subrun(post)
+ if new then start.post = new end
+ end
+ local replace = start.replace
+ if replace then
+ local new = subrun(replace)
+ if new then start.replace = new end
+ end
+elseif typ == "gpos_single" or typ == "gpos_pair" then
+ kerndisc(start)
+ end
+ start = start.next
+ elseif id == whatsit_code then
+ local subtype = start.subtype
+ if subtype == dir_code then
+ local dir = start.dir
+ if dir == "+TRT" or dir == "+TLT" then
+ topstack = topstack + 1
+ dirstack[topstack] = dir
+ elseif dir == "-TRT" or dir == "-TLT" then
+ topstack = topstack - 1
+ end
+ local newdir = dirstack[topstack]
+ if newdir == "+TRT" then
+ rlmode = -1
+ elseif newdir == "+TLT" then
+ rlmode = 1
+ else
+ rlmode = rlparmode
+ end
+ if trace_directions then
+ report_process("directions after txtdir %a: parmode %a, txtmode %a, # stack %a, new dir %a",dir,rlparmode,rlmode,topstack,newdir)
+ end
+ elseif subtype == localpar_code then
+ local dir = start.dir
+ if dir == "TRT" then
+ rlparmode = -1
+ elseif dir == "TLT" then
+ rlparmode = 1
+ else
+ rlparmode = 0
+ end
+ rlmode = rlparmode
+ if trace_directions then
+ report_process("directions after pardir %a: parmode %a, txtmode %a",dir,rlparmode,rlmode)
+ end
+ end
+ start = start.next
+ elseif id == math_code then
+ start = end_of_math(start).next
+ else
+ start = start.next
+ end
+ end
+ end
+ end
+ if success then
+ done = true
+ end
+ if trace_steps then -- ?
+ registerstep(head)
+ end
+ end
+ return head, done
+end
+
+local function generic(lookupdata,lookupname,unicode,lookuphash)
+ local target = lookuphash[lookupname]
+ if target then
+ target[unicode] = lookupdata
+ else
+ lookuphash[lookupname] = { [unicode] = lookupdata }
+ end
+end
+
+local action = {
+
+ substitution = generic,
+ multiple = generic,
+ alternate = generic,
+ position = generic,
+
+ ligature = function(lookupdata,lookupname,unicode,lookuphash)
+ local target = lookuphash[lookupname]
+ if not target then
+ target = { }
+ lookuphash[lookupname] = target
+ end
+ for i=1,#lookupdata do
+ local li = lookupdata[i]
+ local tu = target[li]
+ if not tu then
+ tu = { }
+ target[li] = tu
+ end
+ target = tu
+ end
+ target.ligature = unicode
+ end,
+
+ pair = function(lookupdata,lookupname,unicode,lookuphash)
+ local target = lookuphash[lookupname]
+ if not target then
+ target = { }
+ lookuphash[lookupname] = target
+ end
+ local others = target[unicode]
+ local paired = lookupdata[1]
+ if others then
+ others[paired] = lookupdata
+ else
+ others = { [paired] = lookupdata }
+ target[unicode] = others
+ end
+ end,
+
+}
+
+local function prepare_lookups(tfmdata)
+
+ local rawdata = tfmdata.shared.rawdata
+ local resources = rawdata.resources
+ local lookuphash = resources.lookuphash
+ local anchor_to_lookup = resources.anchor_to_lookup
+ local lookup_to_anchor = resources.lookup_to_anchor
+ local lookuptypes = resources.lookuptypes
+ local characters = tfmdata.characters
+ local descriptions = tfmdata.descriptions
+
+ -- we cannot free the entries in the descriptions as sometimes we access
+ -- then directly (for instance anchors) ... selectively freeing does save
+ -- much memory as it's only a reference to a table and the slot in the
+ -- description hash is not freed anyway
+
+ for unicode, character in next, characters do -- we cannot loop over descriptions !
+
+ local description = descriptions[unicode]
+
+ if description then
+
+ local lookups = description.slookups
+ if lookups then
+ for lookupname, lookupdata in next, lookups do
+ action[lookuptypes[lookupname]](lookupdata,lookupname,unicode,lookuphash)
+ end
+ end
+
+ local lookups = description.mlookups
+ if lookups then
+ for lookupname, lookuplist in next, lookups do
+ local lookuptype = lookuptypes[lookupname]
+ for l=1,#lookuplist do
+ local lookupdata = lookuplist[l]
+ action[lookuptype](lookupdata,lookupname,unicode,lookuphash)
+ end
+ end
+ end
+
+ local list = description.kerns
+ if list then
+ for lookup, krn in next, list do -- ref to glyph, saves lookup
+ local target = lookuphash[lookup]
+ if target then
+ target[unicode] = krn
+ else
+ lookuphash[lookup] = { [unicode] = krn }
+ end
+ end
+ end
+
+ local list = description.anchors
+ if list then
+ for typ, anchors in next, list do -- types
+ if typ == "mark" or typ == "cexit" then -- or entry?
+ for name, anchor in next, anchors do
+ local lookups = anchor_to_lookup[name]
+ if lookups then
+ for lookup, _ in next, lookups do
+ local target = lookuphash[lookup]
+ if target then
+ target[unicode] = anchors
+ else
+ lookuphash[lookup] = { [unicode] = anchors }
+ end
+ end
+ end
+ end
+ end
+ end
+ end
+
+ end
+
+ end
+
+end
+
+local function split(replacement,original)
+ local result = { }
+ for i=1,#replacement do
+ result[original[i]] = replacement[i]
+ end
+ return result
+end
+
+local valid = {
+ coverage = { chainsub = true, chainpos = true, contextsub = true },
+ reversecoverage = { reversesub = true },
+ glyphs = { chainsub = true, chainpos = true },
+}
+
+local function prepare_contextchains(tfmdata)
+ local rawdata = tfmdata.shared.rawdata
+ local resources = rawdata.resources
+ local lookuphash = resources.lookuphash
+ local lookups = rawdata.lookups
+ if lookups then
+ for lookupname, lookupdata in next, rawdata.lookups do
+ local lookuptype = lookupdata.type
+ if lookuptype then
+ local rules = lookupdata.rules
+ if rules then
+ local format = lookupdata.format
+ local validformat = valid[format]
+ if not validformat then
+ report_prepare("unsupported format %a",format)
+ elseif not validformat[lookuptype] then
+ -- todo: dejavu-serif has one (but i need to see what use it has)
+ report_prepare("unsupported format %a, lookuptype %a, lookupname %a",format,lookuptype,lookupname)
+ else
+ local contexts = lookuphash[lookupname]
+ if not contexts then
+ contexts = { }
+ lookuphash[lookupname] = contexts
+ end
+ local t, nt = { }, 0
+ for nofrules=1,#rules do
+ local rule = rules[nofrules]
+ local current = rule.current
+ local before = rule.before
+ local after = rule.after
+ local replacements = rule.replacements
+ local sequence = { }
+ local nofsequences = 0
+ -- Eventually we can store start, stop and sequence in the cached file
+ -- but then less sharing takes place so best not do that without a lot
+ -- of profiling so let's forget about it.
+ if before then
+ for n=1,#before do
+ nofsequences = nofsequences + 1
+ sequence[nofsequences] = before[n]
+ end
+ end
+ local start = nofsequences + 1
+ for n=1,#current do
+ nofsequences = nofsequences + 1
+ sequence[nofsequences] = current[n]
+ end
+ local stop = nofsequences
+ if after then
+ for n=1,#after do
+ nofsequences = nofsequences + 1
+ sequence[nofsequences] = after[n]
+ end
+ end
+ if sequence[1] then
+ -- Replacements only happen with reverse lookups as they are single only. We
+ -- could pack them into current (replacement value instead of true) and then
+ -- use sequence[start] instead but it's somewhat ugly.
+ nt = nt + 1
+ t[nt] = { nofrules, lookuptype, sequence, start, stop, rule.lookups, replacements }
+ for unic, _ in next, sequence[start] do
+ local cu = contexts[unic]
+ if not cu then
+ contexts[unic] = t
+ end
+ end
+ end
+ end
+ end
+ else
+ -- no rules
+ end
+ else
+ report_prepare("missing lookuptype for lookupname %a",lookupname)
+ end
+ end
+ end
+end
+
+-- we can consider lookuphash == false (initialized but empty) vs lookuphash == table
+
+local function featuresinitializer(tfmdata,value)
+ if true then -- value then
+ -- beware we need to use the topmost properties table
+ local rawdata = tfmdata.shared.rawdata
+ local properties = rawdata.properties
+ if not properties.initialized then
+ local starttime = trace_preparing and os.clock()
+ local resources = rawdata.resources
+ resources.lookuphash = resources.lookuphash or { }
+ prepare_contextchains(tfmdata)
+ prepare_lookups(tfmdata)
+ properties.initialized = true
+ if trace_preparing then
+ report_prepare("preparation time is %0.3f seconds for %a",os.clock()-starttime,tfmdata.properties.fullname)
+ end
+ end
+ end
+end
+
+registerotffeature {
+ name = "features",
+ description = "features",
+ default = true,
+ initializers = {
+ position = 1,
+ node = featuresinitializer,
+ },
+ processors = {
+ node = featuresprocessor,
+ }
+}
+
+-- This can be used for extra handlers, but should be used with care!
+
+otf.handlers = handlers