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authorPhilipp Gesang <phg42.2a@gmail.com>2013-08-11 11:03:23 +0200
committerPhilipp Gesang <phg42.2a@gmail.com>2013-08-11 11:03:23 +0200
commit307f4a6bb5998ee0c853a6344ee6aea2d7669b32 (patch)
tree311cbde47af902018fd68176ddb9752274e357e3 /luaotfload-font-afm.lua
parent7b29a1f85184ae2c1900c2963003647a0e22bc9f (diff)
downloadluaotfload-307f4a6bb5998ee0c853a6344ee6aea2d7669b32.tar.gz
[lib] add font-afm.lua
Diffstat (limited to 'luaotfload-font-afm.lua')
-rw-r--r--luaotfload-font-afm.lua971
1 files changed, 971 insertions, 0 deletions
diff --git a/luaotfload-font-afm.lua b/luaotfload-font-afm.lua
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+++ b/luaotfload-font-afm.lua
@@ -0,0 +1,971 @@
+if not modules then modules = { } end modules ['font-afm'] = {
+ 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"
+}
+
+--[[ldx--
+<p>Some code may look a bit obscure but this has to do with the
+fact that we also use this code for testing and much code evolved
+in the transition from <l n='tfm'/> to <l n='afm'/> to <l
+n='otf'/>.</p>
+
+<p>The following code still has traces of intermediate font support
+where we handles font encodings. Eventually font encoding goes
+away.</p>
+--ldx]]--
+
+local fonts, logs, trackers, containers, resolvers = fonts, logs, trackers, containers, resolvers
+
+local next, type, tonumber = next, type, tonumber
+local format, match, gmatch, lower, gsub, strip = string.format, string.match, string.gmatch, string.lower, string.gsub, string.strip
+local abs = math.abs
+local P, S, C, R, lpegmatch, patterns = lpeg.P, lpeg.S, lpeg.C, lpeg.R, lpeg.match, lpeg.patterns
+local derivetable = table.derive
+
+local trace_features = false trackers.register("afm.features", function(v) trace_features = v end)
+local trace_indexing = false trackers.register("afm.indexing", function(v) trace_indexing = v end)
+local trace_loading = false trackers.register("afm.loading", function(v) trace_loading = v end)
+local trace_defining = false trackers.register("fonts.defining", function(v) trace_defining = v end)
+
+local report_afm = logs.reporter("fonts","afm loading")
+
+local findbinfile = resolvers.findbinfile
+
+local definers = fonts.definers
+local readers = fonts.readers
+local constructors = fonts.constructors
+
+local afm = constructors.newhandler("afm")
+local pfb = constructors.newhandler("pfb")
+
+local afmfeatures = constructors.newfeatures("afm")
+local registerafmfeature = afmfeatures.register
+
+afm.version = 1.410 -- incrementing this number one up will force a re-cache
+afm.cache = containers.define("fonts", "afm", afm.version, true)
+afm.autoprefixed = true -- this will become false some day (catches texnansi-blabla.*)
+
+afm.helpdata = { } -- set later on so no local for this
+afm.syncspace = true -- when true, nicer stretch values
+afm.addligatures = true -- best leave this set to true
+afm.addtexligatures = true -- best leave this set to true
+afm.addkerns = true -- best leave this set to true
+
+local function setmode(tfmdata,value)
+ if value then
+ tfmdata.properties.mode = lower(value)
+ end
+end
+
+registerafmfeature {
+ name = "mode",
+ description = "mode",
+ initializers = {
+ base = setmode,
+ node = setmode,
+ }
+}
+
+--[[ldx--
+<p>We start with the basic reader which we give a name similar to the
+built in <l n='tfm'/> and <l n='otf'/> reader.</p>
+--ldx]]--
+
+--~ Comment FONTIDENTIFIER LMMATHSYMBOLS10
+--~ Comment CODINGSCHEME TEX MATH SYMBOLS
+--~ Comment DESIGNSIZE 10.0 pt
+--~ Comment CHECKSUM O 4261307036
+--~ Comment SPACE 0 plus 0 minus 0
+--~ Comment QUAD 1000
+--~ Comment EXTRASPACE 0
+--~ Comment NUM 676.508 393.732 443.731
+--~ Comment DENOM 685.951 344.841
+--~ Comment SUP 412.892 362.892 288.889
+--~ Comment SUB 150 247.217
+--~ Comment SUPDROP 386.108
+--~ Comment SUBDROP 50
+--~ Comment DELIM 2390 1010
+--~ Comment AXISHEIGHT 250
+
+local comment = P("Comment")
+local spacing = patterns.spacer -- S(" \t")^1
+local lineend = patterns.newline -- S("\n\r")
+local words = C((1 - lineend)^1)
+local number = C((R("09") + S("."))^1) / tonumber * spacing^0
+local data = lpeg.Carg(1)
+
+local pattern = ( -- needs testing ... not used anyway as we no longer need math afm's
+ comment * spacing *
+ (
+ data * (
+ ("CODINGSCHEME" * spacing * words ) / function(fd,a) end +
+ ("DESIGNSIZE" * spacing * number * words ) / function(fd,a) fd[ 1] = a end +
+ ("CHECKSUM" * spacing * number * words ) / function(fd,a) fd[ 2] = a end +
+ ("SPACE" * spacing * number * "plus" * number * "minus" * number) / function(fd,a,b,c) fd[ 3], fd[ 4], fd[ 5] = a, b, c end +
+ ("QUAD" * spacing * number ) / function(fd,a) fd[ 6] = a end +
+ ("EXTRASPACE" * spacing * number ) / function(fd,a) fd[ 7] = a end +
+ ("NUM" * spacing * number * number * number ) / function(fd,a,b,c) fd[ 8], fd[ 9], fd[10] = a, b, c end +
+ ("DENOM" * spacing * number * number ) / function(fd,a,b ) fd[11], fd[12] = a, b end +
+ ("SUP" * spacing * number * number * number ) / function(fd,a,b,c) fd[13], fd[14], fd[15] = a, b, c end +
+ ("SUB" * spacing * number * number ) / function(fd,a,b) fd[16], fd[17] = a, b end +
+ ("SUPDROP" * spacing * number ) / function(fd,a) fd[18] = a end +
+ ("SUBDROP" * spacing * number ) / function(fd,a) fd[19] = a end +
+ ("DELIM" * spacing * number * number ) / function(fd,a,b) fd[20], fd[21] = a, b end +
+ ("AXISHEIGHT" * spacing * number ) / function(fd,a) fd[22] = a end
+ )
+ + (1-lineend)^0
+ )
+ + (1-comment)^1
+)^0
+
+local function scan_comment(str)
+ local fd = { }
+ lpegmatch(pattern,str,1,fd)
+ return fd
+end
+
+-- On a rainy day I will rewrite this in lpeg ... or we can use the (slower) fontloader
+-- as in now supports afm/pfb loading but it's not too bad to have different methods
+-- for testing approaches.
+
+local keys = { }
+
+function keys.FontName (data,line) data.metadata.fontname = strip (line) -- get rid of spaces
+ data.metadata.fullname = strip (line) end
+function keys.ItalicAngle (data,line) data.metadata.italicangle = tonumber (line) end
+function keys.IsFixedPitch(data,line) data.metadata.isfixedpitch = toboolean(line,true) end
+function keys.CharWidth (data,line) data.metadata.charwidth = tonumber (line) end
+function keys.XHeight (data,line) data.metadata.xheight = tonumber (line) end
+function keys.Descender (data,line) data.metadata.descender = tonumber (line) end
+function keys.Ascender (data,line) data.metadata.ascender = tonumber (line) end
+function keys.Comment (data,line)
+ -- Comment DesignSize 12 (pts)
+ -- Comment TFM designsize: 12 (in points)
+ line = lower(line)
+ local designsize = match(line,"designsize[^%d]*(%d+)")
+ if designsize then data.metadata.designsize = tonumber(designsize) end
+end
+
+local function get_charmetrics(data,charmetrics,vector)
+ local characters = data.characters
+ local chr, ind = { }, 0
+ for k,v in gmatch(charmetrics,"([%a]+) +(.-) *;") do
+ if k == 'C' then
+ v = tonumber(v)
+ if v < 0 then
+ ind = ind + 1 -- ?
+ else
+ ind = v
+ end
+ chr = {
+ index = ind
+ }
+ elseif k == 'WX' then
+ chr.width = tonumber(v)
+ elseif k == 'N' then
+ characters[v] = chr
+ elseif k == 'B' then
+ local llx, lly, urx, ury = match(v,"^ *(.-) +(.-) +(.-) +(.-)$")
+ chr.boundingbox = { tonumber(llx), tonumber(lly), tonumber(urx), tonumber(ury) }
+ elseif k == 'L' then
+ local plus, becomes = match(v,"^(.-) +(.-)$")
+ local ligatures = chr.ligatures
+ if ligatures then
+ ligatures[plus] = becomes
+ else
+ chr.ligatures = { [plus] = becomes }
+ end
+ end
+ end
+end
+
+local function get_kernpairs(data,kernpairs)
+ local characters = data.characters
+ for one, two, value in gmatch(kernpairs,"KPX +(.-) +(.-) +(.-)\n") do
+ local chr = characters[one]
+ if chr then
+ local kerns = chr.kerns
+ if kerns then
+ kerns[two] = tonumber(value)
+ else
+ chr.kerns = { [two] = tonumber(value) }
+ end
+ end
+ end
+end
+
+local function get_variables(data,fontmetrics)
+ for key, rest in gmatch(fontmetrics,"(%a+) *(.-)[\n\r]") do
+ local keyhandler = keys[key]
+ if keyhandler then
+ keyhandler(data,rest)
+ end
+ end
+end
+
+local function get_indexes(data,pfbname)
+ data.resources.filename = resolvers.unresolve(pfbname) -- no shortcut
+ local pfbblob = fontloader.open(pfbname)
+ if pfbblob then
+ local characters = data.characters
+ local pfbdata = fontloader.to_table(pfbblob)
+ if pfbdata then
+ local glyphs = pfbdata.glyphs
+ if glyphs then
+ if trace_loading then
+ report_afm("getting index data from %a",pfbname)
+ end
+ for index, glyph in next, glyphs do
+ local name = glyph.name
+ if name then
+ local char = characters[name]
+ if char then
+ if trace_indexing then
+ report_afm("glyph %a has index %a",name,index)
+ end
+ char.index = index
+ end
+ end
+ end
+ elseif trace_loading then
+ report_afm("no glyph data in pfb file %a",pfbname)
+ end
+ elseif trace_loading then
+ report_afm("no data in pfb file %a",pfbname)
+ end
+ fontloader.close(pfbblob)
+ elseif trace_loading then
+ report_afm("invalid pfb file %a",pfbname)
+ end
+end
+
+local function readafm(filename)
+ local ok, afmblob, size = resolvers.loadbinfile(filename) -- has logging
+ if ok and afmblob then
+ local data = {
+ resources = {
+ filename = resolvers.unresolve(filename),
+ version = afm.version,
+ creator = "context mkiv",
+ },
+ properties = {
+ hasitalics = false,
+ },
+ goodies = {
+ },
+ metadata = {
+ filename = file.removesuffix(file.basename(filename))
+ },
+ characters = {
+ -- a temporary store
+ },
+ descriptions = {
+ -- the final store
+ },
+ }
+ afmblob = gsub(afmblob,"StartCharMetrics(.-)EndCharMetrics", function(charmetrics)
+ if trace_loading then
+ report_afm("loading char metrics")
+ end
+ get_charmetrics(data,charmetrics,vector)
+ return ""
+ end)
+ afmblob = gsub(afmblob,"StartKernPairs(.-)EndKernPairs", function(kernpairs)
+ if trace_loading then
+ report_afm("loading kern pairs")
+ end
+ get_kernpairs(data,kernpairs)
+ return ""
+ end)
+ afmblob = gsub(afmblob,"StartFontMetrics%s+([%d%.]+)(.-)EndFontMetrics", function(version,fontmetrics)
+ if trace_loading then
+ report_afm("loading variables")
+ end
+ data.afmversion = version
+ get_variables(data,fontmetrics)
+ data.fontdimens = scan_comment(fontmetrics) -- todo: all lpeg, no time now
+ return ""
+ end)
+ return data
+ else
+ if trace_loading then
+ report_afm("no valid afm file %a",filename)
+ end
+ return nil
+ end
+end
+
+--[[ldx--
+<p>We cache files. Caching is taken care of in the loader. We cheat a bit
+by adding ligatures and kern information to the afm derived data. That
+way we can set them faster when defining a font.</p>
+--ldx]]--
+
+local addkerns, addligatures, addtexligatures, unify, normalize -- we will implement these later
+
+function afm.load(filename)
+ -- hm, for some reasons not resolved yet
+ filename = resolvers.findfile(filename,'afm') or ""
+ if filename ~= "" then
+ local name = file.removesuffix(file.basename(filename))
+ local data = containers.read(afm.cache,name)
+ local attr = lfs.attributes(filename)
+ local size, time = attr.size or 0, attr.modification or 0
+ --
+ local pfbfile = file.replacesuffix(name,"pfb")
+ local pfbname = resolvers.findfile(pfbfile,"pfb") or ""
+ if pfbname == "" then
+ pfbname = resolvers.findfile(file.basename(pfbfile),"pfb") or ""
+ end
+ local pfbsize, pfbtime = 0, 0
+ if pfbname ~= "" then
+ local attr = lfs.attributes(pfbname)
+ pfbsize = attr.size or 0
+ pfbtime = attr.modification or 0
+ end
+ if not data or data.size ~= size or data.time ~= time or data.pfbsize ~= pfbsize or data.pfbtime ~= pfbtime then
+ report_afm("reading %a",filename)
+ data = readafm(filename)
+ if data then
+ if pfbname ~= "" then
+ get_indexes(data,pfbname)
+ elseif trace_loading then
+ report_afm("no pfb file for %a",filename)
+ end
+ report_afm("unifying %a",filename)
+ unify(data,filename)
+ if afm.addligatures then
+ report_afm("add ligatures")
+ addligatures(data)
+ end
+ if afm.addtexligatures then
+ report_afm("add tex ligatures")
+ addtexligatures(data)
+ end
+ if afm.addkerns then
+ report_afm("add extra kerns")
+ addkerns(data)
+ end
+ normalize(data)
+ report_afm("add tounicode data")
+ fonts.mappings.addtounicode(data,filename)
+ data.size = size
+ data.time = time
+ data.pfbsize = pfbsize
+ data.pfbtime = pfbtime
+ report_afm("saving %a in cache",name)
+ data = containers.write(afm.cache, name, data)
+ data = containers.read(afm.cache,name)
+ end
+ end
+ return data
+ else
+ return nil
+ end
+end
+
+local uparser = fonts.mappings.makenameparser()
+
+unify = function(data, filename)
+ local unicodevector = fonts.encodings.agl.unicodes -- loaded runtime in context
+ local unicodes, names = { }, { }
+ local private = constructors.privateoffset
+ local descriptions = data.descriptions
+ for name, blob in next, data.characters do
+ local code = unicodevector[name] -- or characters.name_to_unicode[name]
+ if not code then
+ code = lpegmatch(uparser,name)
+ if not code then
+ code = private
+ private = private + 1
+ report_afm("assigning private slot %U for unknown glyph name %a",code,name)
+ end
+ end
+ local index = blob.index
+ unicodes[name] = code
+ names[name] = index
+ blob.name = name
+ descriptions[code] = {
+ boundingbox = blob.boundingbox,
+ width = blob.width,
+ kerns = blob.kerns,
+ index = index,
+ name = name,
+ }
+ end
+ for unicode, description in next, descriptions do
+ local kerns = description.kerns
+ if kerns then
+ local krn = { }
+ for name, kern in next, kerns do
+ local unicode = unicodes[name]
+ if unicode then
+ krn[unicode] = kern
+ else
+ print(unicode,name)
+ end
+ end
+ description.kerns = krn
+ end
+ end
+ data.characters = nil
+ local resources = data.resources
+ local filename = resources.filename or file.removesuffix(file.basename(filename))
+ resources.filename = resolvers.unresolve(filename) -- no shortcut
+ resources.unicodes = unicodes -- name to unicode
+ resources.marks = { } -- todo
+ resources.names = names -- name to index
+ resources.private = private
+end
+
+normalize = function(data)
+end
+
+--[[ldx--
+<p>These helpers extend the basic table with extra ligatures, texligatures
+and extra kerns. This saves quite some lookups later.</p>
+--ldx]]--
+
+local addthem = function(rawdata,ligatures)
+ if ligatures then
+ local descriptions = rawdata.descriptions
+ local resources = rawdata.resources
+ local unicodes = resources.unicodes
+ local names = resources.names
+ for ligname, ligdata in next, ligatures do
+ local one = descriptions[unicodes[ligname]]
+ if one then
+ for _, pair in next, ligdata do
+ local two, three = unicodes[pair[1]], unicodes[pair[2]]
+ if two and three then
+ local ol = one.ligatures
+ if ol then
+ if not ol[two] then
+ ol[two] = three
+ end
+ else
+ one.ligatures = { [two] = three }
+ end
+ end
+ end
+ end
+ end
+ end
+end
+
+addligatures = function(rawdata) addthem(rawdata,afm.helpdata.ligatures ) end
+addtexligatures = function(rawdata) addthem(rawdata,afm.helpdata.texligatures) end
+
+--[[ldx--
+<p>We keep the extra kerns in separate kerning tables so that we can use
+them selectively.</p>
+--ldx]]--
+
+-- This is rather old code (from the beginning when we had only tfm). If
+-- we unify the afm data (now we have names all over the place) then
+-- we can use shcodes but there will be many more looping then. But we
+-- could get rid of the tables in char-cmp then. Als, in the generic version
+-- we don't use the character database. (Ok, we can have a context specific
+-- variant).
+
+addkerns = function(rawdata) -- using shcodes is not robust here
+ local descriptions = rawdata.descriptions
+ local resources = rawdata.resources
+ local unicodes = resources.unicodes
+ local function do_it_left(what)
+ if what then
+ for unicode, description in next, descriptions do
+ local kerns = description.kerns
+ if kerns then
+ local extrakerns
+ for complex, simple in next, what do
+ complex = unicodes[complex]
+ simple = unicodes[simple]
+ if complex and simple then
+ local ks = kerns[simple]
+ if ks and not kerns[complex] then
+ if extrakerns then
+ extrakerns[complex] = ks
+ else
+ extrakerns = { [complex] = ks }
+ end
+ end
+ end
+ end
+ if extrakerns then
+ description.extrakerns = extrakerns
+ end
+ end
+ end
+ end
+ end
+ local function do_it_copy(what)
+ if what then
+ for complex, simple in next, what do
+ complex = unicodes[complex]
+ simple = unicodes[simple]
+ if complex and simple then
+ local complexdescription = descriptions[complex]
+ if complexdescription then -- optional
+ local simpledescription = descriptions[complex]
+ if simpledescription then
+ local extrakerns
+ local kerns = simpledescription.kerns
+ if kerns then
+ for unicode, kern in next, kerns do
+ if extrakerns then
+ extrakerns[unicode] = kern
+ else
+ extrakerns = { [unicode] = kern }
+ end
+ end
+ end
+ local extrakerns = simpledescription.extrakerns
+ if extrakerns then
+ for unicode, kern in next, extrakerns do
+ if extrakerns then
+ extrakerns[unicode] = kern
+ else
+ extrakerns = { [unicode] = kern }
+ end
+ end
+ end
+ if extrakerns then
+ complexdescription.extrakerns = extrakerns
+ end
+ end
+ end
+ end
+ end
+ end
+ end
+ -- add complex with values of simplified when present
+ do_it_left(afm.helpdata.leftkerned)
+ do_it_left(afm.helpdata.bothkerned)
+ -- copy kerns from simple char to complex char unless set
+ do_it_copy(afm.helpdata.bothkerned)
+ do_it_copy(afm.helpdata.rightkerned)
+end
+
+--[[ldx--
+<p>The copying routine looks messy (and is indeed a bit messy).</p>
+--ldx]]--
+
+local function adddimensions(data) -- we need to normalize afm to otf i.e. indexed table instead of name
+ if data then
+ for unicode, description in next, data.descriptions do
+ local bb = description.boundingbox
+ if bb then
+ local ht, dp = bb[4], -bb[2]
+ if ht == 0 or ht < 0 then
+ -- no need to set it and no negative heights, nil == 0
+ else
+ description.height = ht
+ end
+ if dp == 0 or dp < 0 then
+ -- no negative depths and no negative depths, nil == 0
+ else
+ description.depth = dp
+ end
+ end
+ end
+ end
+end
+
+local function copytotfm(data)
+ if data and data.descriptions then
+ local metadata = data.metadata
+ local resources = data.resources
+ local properties = derivetable(data.properties)
+ local descriptions = derivetable(data.descriptions)
+ local goodies = derivetable(data.goodies)
+ local characters = { }
+ local parameters = { }
+ local unicodes = resources.unicodes
+ --
+ for unicode, description in next, data.descriptions do -- use parent table
+ characters[unicode] = { }
+ end
+ --
+ local filename = constructors.checkedfilename(resources)
+ local fontname = metadata.fontname or metadata.fullname
+ local fullname = metadata.fullname or metadata.fontname
+ local endash = unicodes['space']
+ local emdash = unicodes['emdash']
+ local spacer = "space"
+ local spaceunits = 500
+ --
+ local monospaced = metadata.isfixedpitch
+ local charwidth = metadata.charwidth
+ local italicangle = metadata.italicangle
+ local charxheight = metadata.xheight and metadata.xheight > 0 and metadata.xheight
+ properties.monospaced = monospaced
+ parameters.italicangle = italicangle
+ parameters.charwidth = charwidth
+ parameters.charxheight = charxheight
+ -- same as otf
+ if properties.monospaced then
+ if descriptions[endash] then
+ spaceunits, spacer = descriptions[endash].width, "space"
+ end
+ if not spaceunits and descriptions[emdash] then
+ spaceunits, spacer = descriptions[emdash].width, "emdash"
+ end
+ if not spaceunits and charwidth then
+ spaceunits, spacer = charwidth, "charwidth"
+ end
+ else
+ if descriptions[endash] then
+ spaceunits, spacer = descriptions[endash].width, "space"
+ end
+ if not spaceunits and charwidth then
+ spaceunits, spacer = charwidth, "charwidth"
+ end
+ end
+ spaceunits = tonumber(spaceunits)
+ if spaceunits < 200 then
+ -- todo: warning
+ end
+ --
+ parameters.slant = 0
+ parameters.space = spaceunits
+ parameters.space_stretch = 500
+ parameters.space_shrink = 333
+ parameters.x_height = 400
+ parameters.quad = 1000
+ --
+ if italicangle then
+ parameters.italicangle = italicangle
+ parameters.italicfactor = math.cos(math.rad(90+italicangle))
+ parameters.slant = - math.round(math.tan(italicangle*math.pi/180))
+ end
+ if monospaced then
+ parameters.space_stretch = 0
+ parameters.space_shrink = 0
+ elseif afm.syncspace then
+ parameters.space_stretch = spaceunits/2
+ parameters.space_shrink = spaceunits/3
+ end
+ parameters.extra_space = parameters.space_shrink
+ if charxheight then
+ parameters.x_height = charxheight
+ else
+ -- same as otf
+ local x = unicodes['x']
+ if x then
+ local x = descriptions[x]
+ if x then
+ parameters.x_height = x.height
+ end
+ end
+ --
+ end
+ local fd = data.fontdimens
+ if fd and fd[8] and fd[9] and fd[10] then -- math
+ for k,v in next, fd do
+ parameters[k] = v
+ end
+ end
+ --
+ parameters.designsize = (metadata.designsize or 10)*65536
+ parameters.ascender = abs(metadata.ascender or 0)
+ parameters.descender = abs(metadata.descender or 0)
+ parameters.units = 1000
+ --
+ properties.spacer = spacer
+ properties.encodingbytes = 2
+ properties.format = fonts.formats[filename] or "type1"
+ properties.filename = filename
+ properties.fontname = fontname
+ properties.fullname = fullname
+ properties.psname = fullname
+ properties.name = filename or fullname or fontname
+ --
+ if next(characters) then
+ return {
+ characters = characters,
+ descriptions = descriptions,
+ parameters = parameters,
+ resources = resources,
+ properties = properties,
+ goodies = goodies,
+ }
+ end
+ end
+ return nil
+end
+
+--[[ldx--
+<p>Originally we had features kind of hard coded for <l n='afm'/>
+files but since I expect to support more font formats, I decided
+to treat this fontformat like any other and handle features in a
+more configurable way.</p>
+--ldx]]--
+
+function afm.setfeatures(tfmdata,features)
+ local okay = constructors.initializefeatures("afm",tfmdata,features,trace_features,report_afm)
+ if okay then
+ return constructors.collectprocessors("afm",tfmdata,features,trace_features,report_afm)
+ else
+ return { } -- will become false
+ end
+end
+
+local function checkfeatures(specification)
+end
+
+local function afmtotfm(specification)
+ local afmname = specification.filename or specification.name
+ if specification.forced == "afm" or specification.format == "afm" then -- move this one up
+ if trace_loading then
+ report_afm("forcing afm format for %a",afmname)
+ end
+ else
+ local tfmname = findbinfile(afmname,"ofm") or ""
+ if tfmname ~= "" then
+ if trace_loading then
+ report_afm("fallback from afm to tfm for %a",afmname)
+ end
+ return -- just that
+ end
+ end
+ if afmname ~= "" then
+ -- weird, isn't this already done then?
+ local features = constructors.checkedfeatures("afm",specification.features.normal)
+ specification.features.normal = features
+ constructors.hashinstance(specification,true) -- also weird here
+ --
+ specification = definers.resolve(specification) -- new, was forgotten
+ local cache_id = specification.hash
+ local tfmdata = containers.read(constructors.cache, cache_id) -- cache with features applied
+ if not tfmdata then
+ local rawdata = afm.load(afmname)
+ if rawdata and next(rawdata) then
+ adddimensions(rawdata)
+ tfmdata = copytotfm(rawdata)
+ if tfmdata and next(tfmdata) then
+ local shared = tfmdata.shared
+ if not shared then
+ shared = { }
+ tfmdata.shared = shared
+ end
+ shared.rawdata = rawdata
+ shared.features = features
+ shared.processes = afm.setfeatures(tfmdata,features)
+ end
+ elseif trace_loading then
+ report_afm("no (valid) afm file found with name %a",afmname)
+ end
+ tfmdata = containers.write(constructors.cache,cache_id,tfmdata)
+ end
+ return tfmdata
+ end
+end
+
+--[[ldx--
+<p>As soon as we could intercept the <l n='tfm'/> reader, I implemented an
+<l n='afm'/> reader. Since traditional <l n='pdftex'/> could use <l n='opentype'/>
+fonts with <l n='afm'/> companions, the following method also could handle
+those cases, but now that we can handle <l n='opentype'/> directly we no longer
+need this features.</p>
+--ldx]]--
+
+local function read_from_afm(specification)
+ local tfmdata = afmtotfm(specification)
+ if tfmdata then
+ tfmdata.properties.name = specification.name
+ tfmdata = constructors.scale(tfmdata, specification)
+ local allfeatures = tfmdata.shared.features or specification.features.normal
+ constructors.applymanipulators("afm",tfmdata,allfeatures,trace_features,report_afm)
+ fonts.loggers.register(tfmdata,'afm',specification)
+ end
+ return tfmdata
+end
+
+--[[ldx--
+<p>Here comes the implementation of a few features. We only implement
+those that make sense for this format.</p>
+--ldx]]--
+
+local function prepareligatures(tfmdata,ligatures,value)
+ if value then
+ local descriptions = tfmdata.descriptions
+ for unicode, character in next, tfmdata.characters do
+ local description = descriptions[unicode]
+ local dligatures = description.ligatures
+ if dligatures then
+ local cligatures = character.ligatures
+ if not cligatures then
+ cligatures = { }
+ character.ligatures = cligatures
+ end
+ for unicode, ligature in next, dligatures do
+ cligatures[unicode] = {
+ char = ligature,
+ type = 0
+ }
+ end
+ end
+ end
+ end
+end
+
+local function preparekerns(tfmdata,kerns,value)
+ if value then
+ local rawdata = tfmdata.shared.rawdata
+ local resources = rawdata.resources
+ local unicodes = resources.unicodes
+ local descriptions = tfmdata.descriptions
+ for u, chr in next, tfmdata.characters do
+ local d = descriptions[u]
+ local newkerns = d[kerns]
+ if newkerns then
+ local kerns = chr.kerns
+ if not kerns then
+ kerns = { }
+ chr.kerns = kerns
+ end
+ for k,v in next, newkerns do
+ local uk = unicodes[k]
+ if uk then
+ kerns[uk] = v
+ end
+ end
+ end
+ end
+ end
+end
+
+local list = {
+ -- [0x0022] = 0x201D,
+ [0x0027] = 0x2019,
+ -- [0x0060] = 0x2018,
+}
+
+local function texreplacements(tfmdata,value)
+ local descriptions = tfmdata.descriptions
+ local characters = tfmdata.characters
+ for k, v in next, list do
+ characters [k] = characters [v] -- we forget about kerns
+ descriptions[k] = descriptions[v] -- we forget about kerns
+ end
+end
+
+local function ligatures (tfmdata,value) prepareligatures(tfmdata,'ligatures', value) end
+local function texligatures(tfmdata,value) prepareligatures(tfmdata,'texligatures',value) end
+local function kerns (tfmdata,value) preparekerns (tfmdata,'kerns', value) end
+local function extrakerns (tfmdata,value) preparekerns (tfmdata,'extrakerns', value) end
+
+registerafmfeature {
+ name = "liga",
+ description = "traditional ligatures",
+ initializers = {
+ base = ligatures,
+ node = ligatures,
+ }
+}
+
+registerafmfeature {
+ name = "kern",
+ description = "intercharacter kerning",
+ initializers = {
+ base = kerns,
+ node = kerns,
+ }
+}
+
+registerafmfeature {
+ name = "extrakerns",
+ description = "additional intercharacter kerning",
+ initializers = {
+ base = extrakerns,
+ node = extrakerns,
+ }
+}
+
+registerafmfeature {
+ name = 'tlig',
+ description = 'tex ligatures',
+ initializers = {
+ base = texligatures,
+ node = texligatures,
+ }
+}
+
+registerafmfeature {
+ name = 'trep',
+ description = 'tex replacements',
+ initializers = {
+ base = texreplacements,
+ node = texreplacements,
+ }
+}
+
+-- readers
+
+local check_tfm = readers.check_tfm
+
+fonts.formats.afm = "type1"
+fonts.formats.pfb = "type1"
+
+local function check_afm(specification,fullname)
+ local foundname = findbinfile(fullname, 'afm') or "" -- just to be sure
+ if foundname == "" then
+ foundname = fonts.names.getfilename(fullname,"afm") or ""
+ end
+ if foundname == "" and afm.autoprefixed then
+ local encoding, shortname = match(fullname,"^(.-)%-(.*)$") -- context: encoding-name.*
+ if encoding and shortname and fonts.encodings.known[encoding] then
+ shortname = findbinfile(shortname,'afm') or "" -- just to be sure
+ if shortname ~= "" then
+ foundname = shortname
+ if trace_defining then
+ report_afm("stripping encoding prefix from filename %a",afmname)
+ end
+ end
+ end
+ end
+ if foundname ~= "" then
+ specification.filename = foundname
+ specification.format = "afm"
+ return read_from_afm(specification)
+ end
+end
+
+function readers.afm(specification,method)
+ local fullname, tfmdata = specification.filename or "", nil
+ if fullname == "" then
+ local forced = specification.forced or ""
+ if forced ~= "" then
+ tfmdata = check_afm(specification,specification.name .. "." .. forced)
+ end
+ if not tfmdata then
+ method = method or definers.method or "afm or tfm"
+ if method == "tfm" then
+ tfmdata = check_tfm(specification,specification.name)
+ elseif method == "afm" then
+ tfmdata = check_afm(specification,specification.name)
+ elseif method == "tfm or afm" then
+ tfmdata = check_tfm(specification,specification.name) or check_afm(specification,specification.name)
+ else -- method == "afm or tfm" or method == "" then
+ tfmdata = check_afm(specification,specification.name) or check_tfm(specification,specification.name)
+ end
+ end
+ else
+ tfmdata = check_afm(specification,fullname)
+ end
+ return tfmdata
+end
+
+function readers.pfb(specification,method) -- only called when forced
+ local original = specification.specification
+ if trace_defining then
+ report_afm("using afm reader for %a",original)
+ end
+ specification.specification = gsub(original,"%.pfb",".afm")
+ specification.forced = "afm"
+ return readers.afm(specification,method)
+end