Merge pull request #330 from phi-gamma/master

fontloader update

1 files changed, 442 insertions, 0 deletions

diff --git a/src/fontloader/misc/fontloader-font-ota.lua b/src/fontloader/misc/fontloader-font-ota.lua
new file mode 100644
index 0000000..6a3804a
--- /dev/null
+++ b/src/fontloader/misc/fontloader-font-ota.lua
@@ -0,0 +1,442 @@
+if not modules then modules = { } end modules ['font-ota'] = {
+    version   = 1.001,
+    comment   = "companion to font-otf.lua (analysing)",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+-- context only
+
+local type = type
+
+if not trackers then trackers = { register = function() end } end
+
+----- trace_analyzing = false  trackers.register("otf.analyzing",  function(v) trace_analyzing = v end)
+
+local fonts, nodes, node = fonts, nodes, node
+
+local allocate            = utilities.storage.allocate
+
+local otf                 = fonts.handlers.otf
+
+local analyzers           = fonts.analyzers
+local initializers        = allocate()
+local methods             = allocate()
+
+analyzers.initializers    = initializers
+analyzers.methods         = methods
+
+local a_state             = attributes.private('state')
+
+local nuts                = nodes.nuts
+local tonut               = nuts.tonut
+
+local getfield            = nuts.getfield
+local getnext             = nuts.getnext
+local getprev             = nuts.getprev
+local getprev             = nuts.getprev
+local getprop             = nuts.getprop
+local setprop             = nuts.setprop
+local getfont             = nuts.getfont
+local getsubtype          = nuts.getsubtype
+local getchar             = nuts.getchar
+local ischar              = nuts.is_char
+
+local traverse_id         = nuts.traverse_id
+local traverse_node_list  = nuts.traverse
+local end_of_math         = nuts.end_of_math
+
+local nodecodes           = nodes.nodecodes
+----- glyph_code          = nodecodes.glyph
+local disc_code           = nodecodes.disc
+local math_code           = nodecodes.math
+
+local fontdata            = fonts.hashes.identifiers
+local categories          = characters and characters.categories or { } -- sorry, only in context
+local chardata            = characters and characters.data
+
+local otffeatures         = fonts.constructors.newfeatures("otf")
+local registerotffeature  = otffeatures.register
+
+--[[ldx--
+<p>Analyzers run per script and/or language and are needed in order to
+process features right.</p>
+--ldx]]--
+
+-- never use these numbers directly
+
+local s_init = 1    local s_rphf =  7
+local s_medi = 2    local s_half =  8
+local s_fina = 3    local s_pref =  9
+local s_isol = 4    local s_blwf = 10
+local s_mark = 5    local s_pstf = 11
+local s_rest = 6
+
+local states = {
+    init = s_init,
+    medi = s_medi,
+    med2 = s_medi,
+    fina = s_fina,
+    fin2 = s_fina,
+    fin3 = s_fina,
+    isol = s_isol,
+    mark = s_mark,
+    rest = s_rest,
+    rphf = s_rphf,
+    half = s_half,
+    pref = s_pref,
+    blwf = s_blwf,
+    pstf = s_pstf,
+}
+
+local features = {
+    init = s_init,
+    medi = s_medi,
+    med2 = s_medi,
+    fina = s_fina,
+    fin2 = s_fina,
+    fin3 = s_fina,
+    isol = s_isol,
+ -- mark = s_mark,
+ -- rest = s_rest,
+    rphf = s_rphf,
+    half = s_half,
+    pref = s_pref,
+    blwf = s_blwf,
+    pstf = s_pstf,
+}
+
+analyzers.states          = states
+analyzers.features        = features
+analyzers.useunicodemarks = false
+
+-- todo: analyzers per script/lang, cross font, so we need an font id hash -> script
+-- e.g. latin -> hyphenate, arab -> 1/2/3 analyze -- its own namespace
+
+function analyzers.setstate(head,font)
+    local useunicodemarks  = analyzers.useunicodemarks
+    local tfmdata = fontdata[font]
+    local descriptions = tfmdata.descriptions
+    local first, last, current, n, done = nil, nil, head, 0, false -- maybe make n boolean
+    current = tonut(current)
+    while current do
+        local char, id = ischar(current,font)
+        if char and not getprop(current,a_state) then
+            done = true
+            local d = descriptions[char]
+            if d then
+                if d.class == "mark" then
+                    done = true
+                    setprop(current,a_state,s_mark)
+                elseif useunicodemarks and categories[char] == "mn" then
+                    done = true
+                    setprop(current,a_state,s_mark)
+                elseif n == 0 then
+                    first, last, n = current, current, 1
+                    setprop(current,a_state,s_init)
+                else
+                    last, n = current, n+1
+                    setprop(current,a_state,s_medi)
+                end
+            else -- finish
+                if first and first == last then
+                    setprop(last,a_state,s_isol)
+                elseif last then
+                    setprop(last,a_state,s_fina)
+                end
+                first, last, n = nil, nil, 0
+            end
+        elseif char == false then
+            -- other font
+            if first and first == last then
+                setprop(last,a_state,s_isol)
+            elseif last then
+                setprop(last,a_state,s_fina)
+            end
+            first, last, n = nil, nil, 0
+            if id == math_code then
+                current = end_of_math(current)
+            end
+        elseif id == disc_code then
+            -- always in the middle .. it doesn't make much sense to assign a property
+            -- here ... we might at some point decide to flag the components when present
+            -- but even then it's kind of bogus
+            setprop(current,a_state,s_medi)
+            last = current
+        else -- finish
+            if first and first == last then
+                setprop(last,a_state,s_isol)
+            elseif last then
+                setprop(last,a_state,s_fina)
+            end
+            first, last, n = nil, nil, 0
+            if id == math_code then
+                current = end_of_math(current)
+            end
+        end
+        current = getnext(current)
+    end
+    if first and first == last then
+        setprop(last,a_state,s_isol)
+    elseif last then
+        setprop(last,a_state,s_fina)
+    end
+    return head, done
+end
+
+-- in the future we will use language/script attributes instead of the
+-- font related value, but then we also need dynamic features which is
+-- somewhat slower; and .. we need a chain of them
+
+local function analyzeinitializer(tfmdata,value) -- attr
+    local script, language = otf.scriptandlanguage(tfmdata) -- attr
+    local action = initializers[script]
+    if not action then
+        -- skip
+    elseif type(action) == "function" then
+        return action(tfmdata,value)
+    else
+        local action = action[language]
+        if action then
+            return action(tfmdata,value)
+        end
+    end
+end
+
+local function analyzeprocessor(head,font,attr)
+    local tfmdata = fontdata[font]
+    local script, language = otf.scriptandlanguage(tfmdata,attr)
+    local action = methods[script]
+    if not action then
+        -- skip
+    elseif type(action) == "function" then
+        return action(head,font,attr)
+    else
+        action = action[language]
+        if action then
+            return action(head,font,attr)
+        end
+    end
+    return head, false
+end
+
+registerotffeature {
+    name         = "analyze",
+    description  = "analysis of character classes",
+    default      = true,
+    initializers = {
+        node     = analyzeinitializer,
+    },
+    processors = {
+        position = 1,
+        node     = analyzeprocessor,
+    }
+}
+
+-- latin
+
+methods.latn = analyzers.setstate
+-------.dflt = analyzers.setstate % can be an option or just the default
+
+local arab_warned = { }
+
+local function warning(current,what)
+    local char = getchar(current)
+    if not arab_warned[char] then
+        log.report("analyze","arab: character %C has no %a class",char,what)
+        arab_warned[char] = true
+    end
+end
+
+local mappers = {
+    l = s_init,  -- left
+    d = s_medi,  -- double
+    c = s_medi,  -- joiner
+    r = s_fina,  -- right
+    u = s_isol,  -- nonjoiner
+}
+
+-- we can also use this trick for devanagari
+
+local classifiers = characters.classifiers
+
+if not classifiers then
+
+    local first_arabic,  last_arabic  = characters.blockrange("arabic")
+    local first_syriac,  last_syriac  = characters.blockrange("syriac")
+    local first_mandiac, last_mandiac = characters.blockrange("mandiac")
+    local first_nko,     last_nko     = characters.blockrange("nko")
+
+    classifiers = table.setmetatableindex(function(t,k)
+        local c = chardata[k]
+        local v = false
+        if c then
+            local arabic = c.arabic
+            if arabic then
+                v = mappers[arabic]
+                if not v then
+                    log.report("analyze","error in mapping arabic %C",k)
+                    --  error
+                    v = false
+                end
+            elseif k >= first_arabic  and k <= last_arabic  or k >= first_syriac  and k <= last_syriac  or
+                   k >= first_mandiac and k <= last_mandiac or k >= first_nko     and k <= last_nko     then
+                if categories[k] == "mn" then
+                    v = s_mark
+                else
+                    v = s_rest
+                end
+            end
+        end
+        t[k] = v
+        return v
+    end)
+
+end
+
+function methods.arab(head,font,attr)
+    local first, last = nil, nil
+    local c_first, c_last = nil, nil
+    local current, done = head, false
+    current = tonut(current)
+    while current do
+        local char, id = ischar(current,font)
+        if char and not getprop(current,a_state) then
+            done = true
+            local classifier = classifiers[char]
+            if not classifier then
+                if last then
+                    if c_last == s_medi or c_last == s_fina then
+                        setprop(last,a_state,s_fina)
+                    else
+                        warning(last,"fina")
+                        setprop(last,a_state,s_error)
+                    end
+                    first, last = nil, nil
+                elseif first then
+                    if c_first == s_medi or c_first == s_fina then
+                        setprop(first,a_state,s_isol)
+                    else
+                        warning(first,"isol")
+                        setprop(first,a_state,s_error)
+                    end
+                    first = nil
+                end
+            elseif classifier == s_mark then
+                setprop(current,a_state,s_mark)
+            elseif classifier == s_isol then
+                if last then
+                    if c_last == s_medi or c_last == s_fina then
+                        setprop(last,a_state,s_fina)
+                    else
+                        warning(last,"fina")
+                        setprop(last,a_state,s_error)
+                    end
+                    first, last = nil, nil
+                elseif first then
+                    if c_first == s_medi or c_first == s_fina then
+                        setprop(first,a_state,s_isol)
+                    else
+                        warning(first,"isol")
+                        setprop(first,a_state,s_error)
+                    end
+                    first = nil
+                end
+                setprop(current,a_state,s_isol)
+            elseif classifier == s_medi then
+                if first then
+                    last = current
+                    c_last = classifier
+                    setprop(current,a_state,s_medi)
+                else
+                    setprop(current,a_state,s_init)
+                    first = current
+                    c_first = classifier
+                end
+            elseif classifier == s_fina then
+                if last then
+                    if getprop(last,a_state) ~= s_init then
+                        setprop(last,a_state,s_medi)
+                    end
+                    setprop(current,a_state,s_fina)
+                    first, last = nil, nil
+                elseif first then
+                 -- if getprop(first,a_state) ~= s_init then
+                 --     -- needs checking
+                 --     setprop(first,a_state,s_medi)
+                 -- end
+                    setprop(current,a_state,s_fina)
+                    first = nil
+                else
+                    setprop(current,a_state,s_isol)
+                end
+            else -- classifier == s_rest
+                setprop(current,a_state,s_rest)
+                if last then
+                    if c_last == s_medi or c_last == s_fina then
+                        setprop(last,a_state,s_fina)
+                    else
+                        warning(last,"fina")
+                        setprop(last,a_state,s_error)
+                    end
+                    first, last = nil, nil
+                elseif first then
+                    if c_first == s_medi or c_first == s_fina then
+                        setprop(first,a_state,s_isol)
+                    else
+                        warning(first,"isol")
+                        setprop(first,a_state,s_error)
+                    end
+                    first = nil
+                end
+            end
+        else
+            if last then
+                if c_last == s_medi or c_last == s_fina then
+                    setprop(last,a_state,s_fina)
+                else
+                    warning(last,"fina")
+                    setprop(last,a_state,s_error)
+                end
+                first, last = nil, nil
+            elseif first then
+                if c_first == s_medi or c_first == s_fina then
+                    setprop(first,a_state,s_isol)
+                else
+                    warning(first,"isol")
+                    setprop(first,a_state,s_error)
+                end
+                first = nil
+            end
+            if id == math_code then -- a bit duplicate as we test for glyphs twice
+                current = end_of_math(current)
+            end
+        end
+        current = getnext(current)
+    end
+    if last then
+        if c_last == s_medi or c_last == s_fina then
+            setprop(last,a_state,s_fina)
+        else
+            warning(last,"fina")
+            setprop(last,a_state,s_error)
+        end
+    elseif first then
+        if c_first == s_medi or c_first == s_fina then
+            setprop(first,a_state,s_isol)
+        else
+            warning(first,"isol")
+            setprop(first,a_state,s_error)
+        end
+    end
+    return head, done
+end
+
+methods.syrc = methods.arab
+methods.mand = methods.arab
+methods.nko  = methods.arab
+
+directives.register("otf.analyze.useunicodemarks",function(v)
+    analyzers.useunicodemarks = v
+end)