2017-03-20 17:38:00

1 files changed, 412 insertions, 335 deletions

diff --git a/tex/context/base/mkiv/font-otr.lua b/tex/context/base/mkiv/font-otr.lua
index 43a059bb9..eab33f8b6 100644
--- a/tex/context/base/mkiv/font-otr.lua
+++ b/tex/context/base/mkiv/font-otr.lua
@@ -75,12 +75,13 @@ local setmetatableindex = table.setmetatableindex
 local formatters        = string.formatters
 local sortedkeys        = table.sortedkeys
 local sortedhash        = table.sortedhash
-local stripstring       = string.strip
+local stripstring       = string.nospaces
 local utf16_to_utf8_be  = utf.utf16_to_utf8_be
 
 local report            = logs.reporter("otf reader")
 
 local trace_cmap        = false -- only for checking issues
+local trace_cmap_detail = false -- only for checking issues
 
 fonts                   = fonts or { }
 local handlers          = fonts.handlers or { }
@@ -703,6 +704,34 @@ local panosewidths = {
 
 -- We implement a reader per table.
 
+-- helper
+
+local helpers   = { }
+readers.helpers = helpers
+
+local function gotodatatable(f,fontdata,tag,criterium)
+    if criterium and f then
+        local datatable = fontdata.tables[tag]
+        if datatable then
+            local tableoffset = datatable.offset
+            setposition(f,tableoffset)
+            return tableoffset
+        end
+    end
+end
+
+local function setvariabledata(fontdata,tag,data)
+    local variabledata = fontdata.variabledata
+    if variabledata then
+        variabledata[tag] = data
+    else
+        fontdata.variabledata = { [tag] = data }
+    end
+end
+
+helpers.gotodatatable   = gotodatatable
+helpers.setvariabledata = setvariabledata
+
 -- The name table is probably the first one to load. After all this one provides
 -- useful information about what we deal with. The complication is that we need
 -- to filter the best one available.
@@ -718,14 +747,13 @@ local platformnames = {
 }
 
 function readers.name(f,fontdata,specification)
-    local datatable = fontdata.tables.name
-    if datatable then
-        setposition(f,datatable.offset)
+    local tableoffset = gotodatatable(f,fontdata,"name",true)
+    if tableoffset then
         local format   = readushort(f)
         local nofnames = readushort(f)
         local offset   = readushort(f)
         -- we can also provide a raw list as extra, todo as option
-        local start    = datatable.offset + offset
+        local start    = tableoffset + offset
         local namelists = {
             unicode   = { },
             windows   = { },
@@ -748,25 +776,15 @@ function readers.name(f,fontdata,specification)
                         if encoding and language then
                             local index = readushort(f)
                             local name  = reservednames[index]
-                            if name then
-                                namelist[#namelist+1] = {
-                                    platform = platform,
-                                    encoding = encoding,
-                                    language = language,
-                                    name     = name,
-                                    length   = readushort(f),
-                                    offset   = start + readushort(f),
-                                }
-                            else
-namelist[#namelist+1] = {
-    platform = platform,
-    encoding = encoding,
-    language = language,
-    length   = readushort(f),
-    offset   = start + readushort(f),
-}
---                                 skipshort(f,2)
-                            end
+                            namelist[#namelist+1] = {
+                                platform = platform,
+                                encoding = encoding,
+                                language = language,
+                                name     = name,
+                                index    = index,
+                                length   = readushort(f),
+                                offset   = start + readushort(f),
+                            }
                         else
                             skipshort(f,3)
                         end
@@ -803,6 +821,7 @@ namelist[#namelist+1] = {
             for i=1,#namelist do
                 local name    = namelist[i]
                 local nametag = name.name
+                local index = name.index
                 if not done[nametag or i] then
                     local encoding = name.encoding
                     local language = name.language
@@ -824,7 +843,7 @@ namelist[#namelist+1] = {
                                 language = language,
                             }
                         end
-                        extras[i-1] = content
+                        extras[index] = content
                         done[nametag or i] = true
                     end
                 end
@@ -896,9 +915,8 @@ end
 -- properties table afterwards.
 
 readers["os/2"] = function(f,fontdata)
-    local datatable = fontdata.tables["os/2"]
-    if datatable then
-        setposition(f,datatable.offset)
+    local tableoffset = gotodatatable(f,fontdata,"os/2",true)
+    if tableoffset then
         local version = readushort(f)
         local windowsmetrics = {
             version            = version,
@@ -957,9 +975,8 @@ readers["os/2"] = function(f,fontdata)
 end
 
 readers.head = function(f,fontdata)
-    local datatable = fontdata.tables.head
-    if datatable then
-        setposition(f,datatable.offset)
+    local tableoffset = gotodatatable(f,fontdata,"head",true)
+    if tableoffset then
         local fontheader = {
             version          = readfixed(f),
             revision         = readfixed(f),
@@ -990,68 +1007,60 @@ end
 -- variables are not used but nofmetrics is quite important.
 
 readers.hhea = function(f,fontdata,specification)
-    if specification.details then
-        local datatable = fontdata.tables.hhea
-        if datatable then
-            setposition(f,datatable.offset)
-            fontdata.horizontalheader = {
-                version             = readfixed(f), -- two ushorts: major minor
-                ascender            = readfword(f),
-                descender           = readfword(f),
-                linegap             = readfword(f),
-                maxadvancewidth     = readufword(f),
-                minleftsidebearing  = readfword(f),
-                minrightsidebearing = readfword(f),
-                maxextent           = readfword(f),
-                caretsloperise      = readshort(f),
-                caretsloperun       = readshort(f),
-                caretoffset         = readshort(f),
-                reserved_1          = readshort(f),
-                reserved_2          = readshort(f),
-                reserved_3          = readshort(f),
-                reserved_4          = readshort(f),
-                metricdataformat    = readshort(f),
-                nofmetrics          = readushort(f),
-            }
-        else
-            fontdata.horizontalheader = {
-                nofmetrics = 0,
-            }
-        end
+    local tableoffset = gotodatatable(f,fontdata,"hhea",specification.details)
+    if tableoffset then
+        fontdata.horizontalheader = {
+            version             = readfixed(f), -- two ushorts: major minor
+            ascender            = readfword(f),
+            descender           = readfword(f),
+            linegap             = readfword(f),
+            maxadvancewidth     = readufword(f),
+            minleftsidebearing  = readfword(f),
+            minrightsidebearing = readfword(f),
+            maxextent           = readfword(f),
+            caretsloperise      = readshort(f),
+            caretsloperun       = readshort(f),
+            caretoffset         = readshort(f),
+            reserved_1          = readshort(f),
+            reserved_2          = readshort(f),
+            reserved_3          = readshort(f),
+            reserved_4          = readshort(f),
+            metricdataformat    = readshort(f),
+            nofmetrics          = readushort(f),
+        }
+    else
+        fontdata.horizontalheader = {
+            nofmetrics = 0,
+        }
     end
 end
 
 readers.vhea = function(f,fontdata,specification)
-    if specification.details then
-        local datatable = fontdata.tables.vhea
-        if datatable then
-            setposition(f,datatable.offset)
-            local version = readfixed(f)
-            fontdata.verticalheader = {
-                version              = version,
-                ascender             = readfword(f),
-                descender            = readfword(f),
-                linegap              = readfword(f),
-                maxadvanceheight     = readufword(f),
-                mintopsidebearing    = readfword(f),
-                minbottomsidebearing = readfword(f),
-                maxextent            = readfword(f),
-                caretsloperise       = readshort(f),
-                caretsloperun        = readshort(f),
-                caretoffset          = readshort(f),
-                reserved_1           = readshort(f),
-                reserved_2           = readshort(f),
-                reserved_3           = readshort(f),
-                reserved_4           = readshort(f),
-                metricdataformat     = readshort(f),
-                nofmetrics           = readushort(f),
-            }
---             inspect(fontdata.verticalheader)
-        else
-            fontdata.verticalheader = {
-                nofmetrics = 0,
-            }
-        end
+    local tableoffset = gotodatatable(f,fontdata,"vhea",specification.details)
+    if tableoffset then
+        fontdata.verticalheader = {
+            version              = readfixed(f),
+            ascender             = readfword(f),
+            descender            = readfword(f),
+            linegap              = readfword(f),
+            maxadvanceheight     = readufword(f),
+            mintopsidebearing    = readfword(f),
+            minbottomsidebearing = readfword(f),
+            maxextent            = readfword(f),
+            caretsloperise       = readshort(f),
+            caretsloperun        = readshort(f),
+            caretoffset          = readshort(f),
+            reserved_1           = readshort(f),
+            reserved_2           = readshort(f),
+            reserved_3           = readshort(f),
+            reserved_4           = readshort(f),
+            metricdataformat     = readshort(f),
+            nofmetrics           = readushort(f),
+        }
+    else
+        fontdata.verticalheader = {
+            nofmetrics = 0,
+        }
     end
 end
 
@@ -1061,44 +1070,40 @@ end
 -- fontdata.maximumprofile can be bad
 
 readers.maxp = function(f,fontdata,specification)
-    if specification.details then
-        local datatable = fontdata.tables.maxp
-        if datatable then
-            setposition(f,datatable.offset)
-            local version      = readfixed(f)
-            local nofglyphs    = readushort(f)
-            fontdata.nofglyphs = nofglyphs
-            if version == 0.5 then
-                fontdata.maximumprofile = {
-                    version   = version,
-                    nofglyphs = nofglyphs,
-                }
-                return
-            elseif version == 1.0 then
-                fontdata.maximumprofile = {
-                    version            = version,
-                    nofglyphs          = nofglyphs,
-                    points             = readushort(f),
-                    contours           = readushort(f),
-                    compositepoints    = readushort(f),
-                    compositecontours  = readushort(f),
-                    zones              = readushort(f),
-                    twilightpoints     = readushort(f),
-                    storage            = readushort(f),
-                    functiondefs       = readushort(f),
-                    instructiondefs    = readushort(f),
-                    stackelements      = readushort(f),
-                    sizeofinstructions = readushort(f),
-                    componentelements  = readushort(f),
-                    componentdepth     = readushort(f),
-                }
-                return
-            end
+    local tableoffset = gotodatatable(f,fontdata,"maxp",specification.details)
+    if tableoffset then
+        local version      = readfixed(f)
+        local nofglyphs    = readushort(f)
+        fontdata.nofglyphs = nofglyphs
+        if version == 0.5 then
+            fontdata.maximumprofile = {
+                version   = version,
+                nofglyphs = nofglyphs,
+            }
+        elseif version == 1.0 then
+            fontdata.maximumprofile = {
+                version            = version,
+                nofglyphs          = nofglyphs,
+                points             = readushort(f),
+                contours           = readushort(f),
+                compositepoints    = readushort(f),
+                compositecontours  = readushort(f),
+                zones              = readushort(f),
+                twilightpoints     = readushort(f),
+                storage            = readushort(f),
+                functiondefs       = readushort(f),
+                instructiondefs    = readushort(f),
+                stackelements      = readushort(f),
+                sizeofinstructions = readushort(f),
+                componentelements  = readushort(f),
+                componentdepth     = readushort(f),
+            }
+        else
+            fontdata.maximumprofile = {
+                version   = version,
+                nofglyphs = 0,
+            }
         end
-        fontdata.maximumprofile = {
-            version   = version,
-            nofglyphs = 0,
-        }
     end
 end
 
@@ -1106,86 +1111,78 @@ end
 -- course).
 
 readers.hmtx = function(f,fontdata,specification)
-    if specification.glyphs then
-        local datatable = fontdata.tables.hmtx
-        if datatable then
-            setposition(f,datatable.offset)
-            local horizontalheader = fontdata.horizontalheader
-            local nofmetrics       = horizontalheader.nofmetrics
-            local glyphs           = fontdata.glyphs
-            local nofglyphs        = fontdata.nofglyphs
-            local width            = 0 -- advance
-            local leftsidebearing  = 0
-            for i=0,nofmetrics-1 do
-                local glyph     = glyphs[i]
-                width           = readshort(f)
-                leftsidebearing = readshort(f)
-                if width ~= 0 then
-                    glyph.width = width
-                end
-             -- if leftsidebearing ~= 0 then
-             --     glyph.lsb = leftsidebearing
-             -- end
+    local tableoffset = gotodatatable(f,fontdata,"hmtx",specification.glyphs)
+    if tableoffset then
+        local horizontalheader = fontdata.horizontalheader
+        local nofmetrics       = horizontalheader.nofmetrics
+        local glyphs           = fontdata.glyphs
+        local nofglyphs        = fontdata.nofglyphs
+        local width            = 0 -- advance
+        local leftsidebearing  = 0
+        for i=0,nofmetrics-1 do
+            local glyph     = glyphs[i]
+            width           = readshort(f)
+            leftsidebearing = readshort(f)
+            if width ~= 0 then
+                glyph.width = width
             end
-            -- The next can happen in for instance a monospace font or in a cjk font
-            -- with fixed widths.
-            for i=nofmetrics,nofglyphs-1 do
-                local glyph = glyphs[i]
-                if width ~= 0 then
-                    glyph.width = width
-                end
-             -- if leftsidebearing ~= 0 then
-             --     glyph.lsb = leftsidebearing
-             -- end
+         -- if leftsidebearing ~= 0 then
+         --     glyph.lsb = leftsidebearing
+         -- end
+        end
+        -- The next can happen in for instance a monospace font or in a cjk font
+        -- with fixed widths.
+        for i=nofmetrics,nofglyphs-1 do
+            local glyph = glyphs[i]
+            if width ~= 0 then
+                glyph.width = width
             end
+         -- if leftsidebearing ~= 0 then
+         --     glyph.lsb = leftsidebearing
+         -- end
         end
+        -- hm, there can be a lsb here
     end
 end
 
 readers.vmtx = function(f,fontdata,specification)
-    if specification.glyphs then
-        local datatable = fontdata.tables.vmtx
-        if datatable then
-            setposition(f,datatable.offset)
-            local verticalheader = fontdata.verticalheader
-            local nofmetrics     = verticalheader.nofmetrics
-            local glyphs         = fontdata.glyphs
-            local nofglyphs      = fontdata.nofglyphs
-            local vheight        = 0
-            local vdefault       = verticalheader.ascender + verticalheader.descender
-            local topsidebearing = 0
-            for i=0,nofmetrics-1 do
-                local glyph     = glyphs[i]
-                vheight         = readshort(f)
-                topsidebearing  = readshort(f)
-                if vheight ~= 0 and vheight ~= vdefault then
-                    glyph.vheight = vheight
-                end
-             -- if topsidebearing ~= 0 then
-             --     glyph.tsb = topsidebearing
-             -- end
+    local tableoffset = gotodatatable(f,fontdata,"vmtx",specification.glyphs)
+    if tableoffset then
+        local verticalheader = fontdata.verticalheader
+        local nofmetrics     = verticalheader.nofmetrics
+        local glyphs         = fontdata.glyphs
+        local nofglyphs      = fontdata.nofglyphs
+        local vheight        = 0
+        local vdefault       = verticalheader.ascender + verticalheader.descender
+        local topsidebearing = 0
+        for i=0,nofmetrics-1 do
+            local glyph     = glyphs[i]
+            vheight         = readshort(f)
+            topsidebearing  = readshort(f)
+            if vheight ~= 0 and vheight ~= vdefault then
+                glyph.vheight = vheight
             end
-            -- The next can happen in for instance a monospace font or in a cjk font
-            -- with fixed heights.
-            for i=nofmetrics,nofglyphs-1 do
-                local glyph = glyphs[i]
-                if vheight ~= 0 and vheight ~= vdefault then
-                    glyph.vheight = vheight
-                end
-             -- if topsidebearing ~= 0 then
-             --     glyph.tsb = topsidebearing
-             -- end
+         -- if topsidebearing ~= 0 then
+         --     glyph.tsb = topsidebearing
+         -- end
+        end
+        -- The next can happen in for instance a monospace font or in a cjk font
+        -- with fixed heights.
+        for i=nofmetrics,nofglyphs-1 do
+            local glyph = glyphs[i]
+            if vheight ~= 0 and vheight ~= vdefault then
+                glyph.vheight = vheight
             end
+         -- if topsidebearing ~= 0 then
+         --     glyph.tsb = topsidebearing
+         -- end
         end
     end
 end
 
 readers.vorg = function(f,fontdata,specification)
     if specification.glyphs then
-        local datatable = fontdata.tables.vorg
-        if datatable then
-            report("todo: %s","vorg")
-        end
+     -- reportskippedtable("vorg")
     end
 end
 
@@ -1194,9 +1191,8 @@ end
 -- description is somewhat fuzzy but it is a hybrid with overloads.
 
 readers.post = function(f,fontdata,specification)
-    local datatable = fontdata.tables.post
-    if datatable then
-        setposition(f,datatable.offset)
+    local tableoffset = gotodatatable(f,fontdata,"post",true)
+    if tableoffset then
         local version = readfixed(f)
         fontdata.postscript = {
             version            = version,
@@ -1225,7 +1221,7 @@ readers.post = function(f,fontdata,specification)
             for i=0,nofglyphs-1 do
                 local nameindex = readushort(f)
                 if nameindex >= 258 then
-                    maxnames = maxnames + 1
+                    maxnames  = maxnames + 1
                     nameindex = nameindex - 257
                     indices[nameindex] = i
                 else
@@ -1238,7 +1234,7 @@ readers.post = function(f,fontdata,specification)
                     report("quit post name fetching at %a of %a: %s",i,maxnames,"no index")
                     break
                 else
-                    local length  = readbyte(f)
+                    local length = readbyte(f)
                     if length > 0 then
                         glyphs[mapping].name = readstring(f,length)
                     else
@@ -1365,7 +1361,7 @@ formatreaders[4] = function(f,fontdata,offset)
         elseif offset == 0xFFFF then
             -- bad encoding
         elseif offset == 0 then
-            if trace_cmap then
+            if trace_cmap_detail then
                 report("format 4.%i segment %2i from %C upto %C at index %H",1,segment,startchar,endchar,(startchar + delta) % 65536)
             end
             for unicode=startchar,endchar do
@@ -1398,7 +1394,7 @@ formatreaders[4] = function(f,fontdata,offset)
             end
         else
             local shift = (segment-nofsegments+offset/2) - startchar
-            if trace_cmap then
+            if trace_cmap_detail then
                 report("format 4.%i segment %2i from %C upto %C at index %H",0,segment,startchar,endchar,(startchar + delta) % 65536)
             end
             for unicode=startchar,endchar do
@@ -1448,7 +1444,7 @@ formatreaders[6] = function(f,fontdata,offset)
     local count      = readushort(f)
     local stop       = start+count-1
     local nofdone    = 0
-    if trace_cmap then
+    if trace_cmap_detail then
         report("format 6 from %C to %C",2,start,stop)
     end
     for unicode=start,stop do
@@ -1485,7 +1481,7 @@ formatreaders[12] = function(f,fontdata,offset)
         local first = readulong(f)
         local last  = readulong(f)
         local index = readulong(f)
-        if trace_cmap then
+        if trace_cmap_detail then
             report("format 12 from %C to %C starts at index %i",first,last,index)
         end
         for unicode=first,last do
@@ -1529,7 +1525,7 @@ formatreaders[13] = function(f,fontdata,offset)
         local last  = readulong(f)
         local index = readulong(f)
         if first < privateoffset then
-            if trace_cmap then
+            if trace_cmap_detail then
                 report("format 13 from %C to %C get index %i",first,last,index)
             end
             local glyph   = glyphs[index]
@@ -1635,76 +1631,82 @@ local function checkcmap(f,fontdata,records,platform,encoding,format)
     local p = platforms[platform]
     local e = encodings[p]
     local n = reader(f,fontdata,data) or 0
-    report("cmap checked: platform %i (%s), encoding %i (%s), format %i, new unicodes %i",platform,p,encoding,e and e[encoding] or "?",format,n)
+    if trace_cmap then
+        report("cmap checked: platform %i (%s), encoding %i (%s), format %i, new unicodes %i",platform,p,encoding,e and e[encoding] or "?",format,n)
+    end
     return n
 end
 
 function readers.cmap(f,fontdata,specification)
-    if specification.glyphs then
-        local datatable = fontdata.tables.cmap
-        if datatable then
-            local tableoffset = datatable.offset
-            setposition(f,tableoffset)
-            local version      = readushort(f)
-            local noftables    = readushort(f)
-            local records      = { }
-            local unicodecid   = false
-            local variantcid   = false
-            local variants     = { }
-            local duplicates   = fontdata.duplicates or { }
-            fontdata.duplicates = duplicates
-            for i=1,noftables do
-                local platform = readushort(f)
-                local encoding = readushort(f)
-                local offset   = readulong(f)
-                local record   = records[platform]
-                if not record then
-                    records[platform] = {
-                        [encoding] = {
-                            offsets = { offset },
-                            formats = { },
-                        }
+    local tableoffset = gotodatatable(f,fontdata,"cmap",specification.glyphs)
+    if tableoffset then
+        local version      = readushort(f)
+        local noftables    = readushort(f)
+        local records      = { }
+        local unicodecid   = false
+        local variantcid   = false
+        local variants     = { }
+        local duplicates   = fontdata.duplicates or { }
+        fontdata.duplicates = duplicates
+        for i=1,noftables do
+            local platform = readushort(f)
+            local encoding = readushort(f)
+            local offset   = readulong(f)
+            local record   = records[platform]
+            if not record then
+                records[platform] = {
+                    [encoding] = {
+                        offsets = { offset },
+                        formats = { },
+                    }
+                }
+            else
+                local subtables = record[encoding]
+                if not subtables then
+                    record[encoding] = {
+                        offsets = { offset },
+                        formats = { },
                     }
                 else
-                    local subtables = record[encoding]
-                    if not subtables then
-                        record[encoding] = {
-                            offsets = { offset },
-                            formats = { },
-                        }
-                    else
-                        local offsets = subtables.offsets
-                        offsets[#offsets+1] = offset
-                    end
+                    local offsets = subtables.offsets
+                    offsets[#offsets+1] = offset
                 end
             end
+        end
+        if trace_cmap then
             report("found cmaps:")
-            for platform, record in sortedhash(records) do
-                local p  = platforms[platform]
-                local e  = encodings[p]
-                local sp = supported[platform]
-                local ps = p or "?"
+        end
+        for platform, record in sortedhash(records) do
+            local p  = platforms[platform]
+            local e  = encodings[p]
+            local sp = supported[platform]
+            local ps = p or "?"
+            if trace_cmap then
                 if sp then
                     report("  platform %i: %s",platform,ps)
                 else
                     report("  platform %i: %s (unsupported)",platform,ps)
                 end
-                for encoding, subtables in sortedhash(record) do
-                    local se = sp and sp[encoding]
-                    local es = e and e[encoding] or "?"
+            end
+            for encoding, subtables in sortedhash(record) do
+                local se = sp and sp[encoding]
+                local es = e and e[encoding] or "?"
+                if trace_cmap then
                     if se then
                         report("    encoding %i: %s",encoding,es)
                     else
                         report("    encoding %i: %s (unsupported)",encoding,es)
                     end
-                    local offsets = subtables.offsets
-                    local formats = subtables.formats
-                    for i=1,#offsets do
-                        local offset = tableoffset + offsets[i]
-                        setposition(f,offset)
-                        formats[readushort(f)] = offset
-                    end
-                    record[encoding] = formats
+                end
+                local offsets = subtables.offsets
+                local formats = subtables.formats
+                for i=1,#offsets do
+                    local offset = tableoffset + offsets[i]
+                    setposition(f,offset)
+                    formats[readushort(f)] = offset
+                end
+                record[encoding] = formats
+                if trace_cmap then
                     local list = sortedkeys(formats)
                     for i=1,#list do
                         if not (se and se[list[i]]) then
@@ -1714,27 +1716,27 @@ function readers.cmap(f,fontdata,specification)
                     report("      formats: % t",list)
                 end
             end
-            --
-            local ok = false
-            for i=1,#sequence do
-                local si = sequence[i]
-                local sp, se, sf = si[1], si[2], si[3]
-                if checkcmap(f,fontdata,records,sp,se,sf) > 0 then
-                    ok = true
-                end
-            end
-            if not ok then
-                report("no useable unicode cmap found")
+        end
+        --
+        local ok = false
+        for i=1,#sequence do
+            local si = sequence[i]
+            local sp, se, sf = si[1], si[2], si[3]
+            if checkcmap(f,fontdata,records,sp,se,sf) > 0 then
+                ok = true
             end
-            --
-            fontdata.cidmaps = {
-                version   = version,
-                noftables = noftables,
-                records   = records,
-            }
-        else
-            fontdata.cidmaps = { }
         end
+        if not ok then
+            report("no useable unicode cmap found")
+        end
+        --
+        fontdata.cidmaps = {
+            version   = version,
+            noftables = noftables,
+            records   = records,
+        }
+    else
+        fontdata.cidmaps = { }
     end
 end
 
@@ -1778,42 +1780,39 @@ end
 -- can also be available. Todo: we need a 'fake' lookup for this (analogue to ff).
 
 function readers.kern(f,fontdata,specification)
-    if specification.kerns then
-        local datatable = fontdata.tables.kern
-        if datatable then
-            setposition(f,datatable.offset)
-            local version   = readushort(f)
-            local noftables = readushort(f)
-            for i=1,noftables do
-                local version  = readushort(f)
-                local length   = readushort(f)
-                local coverage = readushort(f)
-                -- bit 8-15 of coverage: format 0 or 2
-                local format   = bit32.rshift(coverage,8) -- is this ok?
-                if format == 0 then
-                    local nofpairs      = readushort(f)
-                    local searchrange   = readushort(f)
-                    local entryselector = readushort(f)
-                    local rangeshift    = readushort(f)
-                    local kerns  = { }
-                    local glyphs = fontdata.glyphs
-                    for i=1,nofpairs do
-                        local left  = readushort(f)
-                        local right = readushort(f)
-                        local kern  = readfword(f)
-                        local glyph = glyphs[left]
-                        local kerns = glyph.kerns
-                        if kerns then
-                            kerns[right] = kern
-                        else
-                            glyph.kerns = { [right] = kern }
-                        end
+    local tableoffset = gotodatatable(f,fontdata,"kern",specification.kerns)
+    if tableoffset then
+        local version   = readushort(f)
+        local noftables = readushort(f)
+        for i=1,noftables do
+            local version  = readushort(f)
+            local length   = readushort(f)
+            local coverage = readushort(f)
+            -- bit 8-15 of coverage: format 0 or 2
+            local format   = bit32.rshift(coverage,8) -- is this ok?
+            if format == 0 then
+                local nofpairs      = readushort(f)
+                local searchrange   = readushort(f)
+                local entryselector = readushort(f)
+                local rangeshift    = readushort(f)
+                local kerns  = { }
+                local glyphs = fontdata.glyphs
+                for i=1,nofpairs do
+                    local left  = readushort(f)
+                    local right = readushort(f)
+                    local kern  = readfword(f)
+                    local glyph = glyphs[left]
+                    local kerns = glyph.kerns
+                    if kerns then
+                        kerns[right] = kern
+                    else
+                        glyph.kerns = { [right] = kern }
                     end
-                elseif format == 2 then
-                    report("todo: kern classes")
-                else
-                    report("todo: kerns")
                 end
+            elseif format == 2 then
+                report("todo: kern classes")
+            else
+                report("todo: kerns")
             end
         end
     end
@@ -1847,7 +1846,7 @@ end
 -- some properties in order to read following tables. When details is true we also
 -- initialize the glyphs data.
 
-local function getinfo(maindata,sub,platformnames,rawfamilynames,metricstoo)
+local function getinfo(maindata,sub,platformnames,rawfamilynames,metricstoo,instancenames)
     local fontdata = sub and maindata.subfonts and maindata.subfonts[sub] or maindata
     local names    = fontdata.names
     local info     = nil
@@ -1872,6 +1871,25 @@ local function getinfo(maindata,sub,platformnames,rawfamilynames,metricstoo)
             if not    familyname then    familyname =    family end
             if not subfamilyname then subfamilyname = subfamily end
         end
+        if platformnames then
+            platformnames = fontdata.platformnames
+        end
+        if instancenames then
+            local variabledata = fontdata.variabledata
+            if variabledata then
+                local instances = variabledata and variabledata.instances
+                if instances then
+                    instancenames = { }
+                    for i=1,#instances do
+                        instancenames[i] = lower(stripstring(instances[i].subfamily))
+                    end
+                else
+                    instancenames = nil
+                end
+            else
+                instancenames = nil
+            end
+        end
         info = { -- we inherit some inconsistencies/choices from ff
             subfontindex   = fontdata.subfontindex or sub or 0,
          -- filename       = filename,
@@ -1902,7 +1920,8 @@ local function getinfo(maindata,sub,platformnames,rawfamilynames,metricstoo)
             capheight      = metrics.capheight, -- not always present and probably crap
             ascender       = metrics.typoascender,
             descender      = metrics.typodescender,
-            platformnames  = platformnames and fontdata.platformnames or nil,
+            platformnames  = platformnames or nil,
+            instancenames  = instancenames or nil,
         }
         if metricstoo then
             local keys = {
@@ -1960,6 +1979,7 @@ local function loadtables(f,specification,offset)
         entryselector = readushort(f), -- not needed
         rangeshift    = readushort(f), -- not needed
         tables        = tables,
+        foundtables   = false,
     }
     for i=1,fontdata.noftables do
         local tag      = lower(stripstring(readstring(f,4)))
@@ -1975,7 +1995,8 @@ local function loadtables(f,specification,offset)
             length   = length,
         }
     end
-    if tables.cff then
+    fontdata.foundtables = sortedkeys(tables)
+    if tables.cff or tables.cff2 then
         fontdata.format = "opentype"
     else
         fontdata.format = "truetype"
@@ -1996,23 +2017,35 @@ local function prepareglyps(fontdata)
     fontdata.mapping = { }
 end
 
-local function readtable(tag,f,fontdata,specification)
+local function readtable(tag,f,fontdata,specification,...)
     local reader = readers[tag]
     if reader then
      -- local t = os.clock()
-        reader(f,fontdata,specification)
+        reader(f,fontdata,specification,...)
      -- report("reading table %a took %0.4f seconds",tag,os.clock()-t)
     end
 end
 
+local variablefonts_supported = context and true or false
+
 local function readdata(f,offset,specification)
+
     local fontdata = loadtables(f,specification,offset)
+
     if specification.glyphs then
         prepareglyps(fontdata)
     end
-    --
+
+    if not variablefonts_supported then
+        specification.instance = nil
+        specification.variable = nil
+        specification.factors  = nil
+    end
+
+    fontdata.temporary = { }
+
     readtable("name",f,fontdata,specification)
-    --
+
     local askedname = specification.askedname
     if askedname then
         local fullname  = getname(fontdata,"fullname") or ""
@@ -2022,7 +2055,35 @@ local function readdata(f,offset,specification)
             return -- keep searching
         end
     end
-    --
+
+    readtable("stat",f,fontdata,specification)
+    readtable("avar",f,fontdata,specification)
+    readtable("fvar",f,fontdata,specification)
+
+    if variablefonts_supported then
+
+        if not specification.factors then
+            local instance = specification.instance
+            if type(instance) == "string" then
+                local factors = helpers.getfactors(fontdata,instance)
+                specification.factors = factors
+                fontdata.factors  = factors
+                fontdata.instance = instance
+                report("user instance: %s, factors: % t",instance,factors)
+            end
+        end
+        if not fontdata.factors then
+            if fontdata.variabledata then
+                local factors = helpers.getfactors(fontdata,true)
+                specification.factors = factors
+                fontdata.factors  = factors
+                fontdata.instance = instance
+                report("font instance: %s, factors: % t",instance,factors)
+            end
+        end
+
+    end
+
     readtable("os/2",f,fontdata,specification)
     readtable("head",f,fontdata,specification)
     readtable("maxp",f,fontdata,specification)
@@ -2032,32 +2093,35 @@ local function readdata(f,offset,specification)
     readtable("vmtx",f,fontdata,specification)
     readtable("vorg",f,fontdata,specification)
     readtable("post",f,fontdata,specification)
+
+    readtable("mvar",f,fontdata,specification)
+    readtable("hvar",f,fontdata,specification)
+    readtable("vvar",f,fontdata,specification)
+
+    readtable("gdef",f,fontdata,specification)
+
     readtable("cff" ,f,fontdata,specification)
+    readtable("cff2",f,fontdata,specification)
+
     readtable("cmap",f,fontdata,specification)
-    readtable("loca",f,fontdata,specification)
-    readtable("glyf",f,fontdata,specification)
+    readtable("loca",f,fontdata,specification) -- maybe load it in glyf
+    readtable("glyf",f,fontdata,specification) -- loads gvar
+
     readtable("colr",f,fontdata,specification)
     readtable("cpal",f,fontdata,specification)
     readtable("svg" ,f,fontdata,specification)
+
     readtable("kern",f,fontdata,specification)
-    readtable("gdef",f,fontdata,specification)
     readtable("gsub",f,fontdata,specification)
     readtable("gpos",f,fontdata,specification)
+
     readtable("math",f,fontdata,specification)
-    --
-    -- there are no proper fonts yet:
-    --
-    readtable("fvar",f,fontdata,specification) -- probably
-    readtable("hvar",f,fontdata,specification)
-    readtable("vvar",f,fontdata,specification)
-    readtable("mvar",f,fontdata,specification) -- probably
-    readtable("vorg",f,fontdata,specification)
-    --
+
     fontdata.locations    = nil
     fontdata.tables       = nil
     fontdata.cidmaps      = nil
     fontdata.dictionaries = nil
-    -- fontdata.cff = nil
+ -- fontdata.cff          = nil
     return fontdata
 end
 
@@ -2132,7 +2196,7 @@ local function loadfontdata(specification)
     end
 end
 
-local function loadfont(specification,n)
+local function loadfont(specification,n,instance)
     if type(specification) == "string" then
         specification = {
             filename    = specification,
@@ -2147,6 +2211,7 @@ local function loadfont(specification,n)
             -- true or number:
             subfont     = n or true,
             tounicode   = false,
+            instance    = instance
         }
     end
     -- if shapes only then
@@ -2162,6 +2227,10 @@ local function loadfont(specification,n)
     if specification.platformnames then
         specification.platformnames = true -- not really used any more
     end
+    if specification.instance or instance then
+        specification.variable = true
+        specification.instance = specification.instance or instance
+    end
     local function message(str)
         report("fatal error in file %a: %s\n%s",specification.filename,str,debug.traceback())
     end
@@ -2173,11 +2242,14 @@ end
 
 -- we need even less, but we can have a 'detail' variant
 
-function readers.loadshapes(filename,n)
+function readers.loadshapes(filename,n,instance,streams)
     local fontdata = loadfont {
         filename = filename,
         shapes   = true,
+        streams  = streams,
+        variable = true,
         subfont  = n,
+        instance = instance,
     }
     if fontdata then
         -- easier on luajit but still we can hit the 64 K stack constants issue
@@ -2202,7 +2274,7 @@ function readers.loadshapes(filename,n)
     }
 end
 
-function readers.loadfont(filename,n)
+function readers.loadfont(filename,n,instance)
     local fontdata = loadfont {
         filename    = filename,
         glyphs      = true,
@@ -2212,9 +2284,9 @@ function readers.loadfont(filename,n)
      -- kerns       = true,
      -- globalkerns = true, -- only for testing, e.g. cambria has different gpos and kern
         subfont     = n,
+        instance    = instance,
     }
     if fontdata then
-        --
         return {
             tableversion  = tableversion,
             creator       = "context mkiv",
@@ -2224,11 +2296,13 @@ function readers.loadfont(filename,n)
             descriptions  = fontdata.descriptions,
             format        = fontdata.format,
             goodies       = { },
-            metadata      = getinfo(fontdata,n,false,false,true), -- no platformnames here !
+            metadata      = getinfo(fontdata,n,false,false,true,true), -- no platformnames here !
             properties    = {
                 hasitalics    = fontdata.hasitalics or false,
                 maxcolorclass = fontdata.maxcolorclass,
                 hascolor      = fontdata.hascolor or false,
+                instance      = fontdata.instance,
+                factors       = fontdata.factors,
             },
             resources     = {
              -- filename      = fontdata.filename,
@@ -2247,7 +2321,8 @@ function readers.loadfont(filename,n)
                 mathconstants = fontdata.mathconstants,
                 colorpalettes = fontdata.colorpalettes,
                 svgshapes     = fontdata.svgshapes,
-                variable      = fontdata.variable,
+                variabledata  = fontdata.variabledata,
+                foundtables   = fontdata.foundtables,
             },
         }
     end
@@ -2259,6 +2334,7 @@ function readers.getinfo(filename,specification) -- string, nil|number|table
     local subfont        = nil
     local platformnames  = false
     local rawfamilynames = false
+    local instancenames  = true
     if type(specification) == "table" then
         subfont        = tonumber(specification.subfont)
         platformnames  = specification.platformnames
@@ -2270,20 +2346,21 @@ function readers.getinfo(filename,specification) -- string, nil|number|table
         filename       = filename,
         details        = true,
         platformnames  = platformnames,
+        instancenames  = true,
      -- rawfamilynames = rawfamilynames,
     }
     if fontdata then
         local subfonts = fontdata.subfonts
         if not subfonts then
-            return getinfo(fontdata,nil,platformnames,rawfamilynames)
+            return getinfo(fontdata,nil,platformnames,rawfamilynames,false,instancenames)
         elseif not subfont then
             local info = { }
             for i=1,#subfonts do
-                info[i] = getinfo(fontdata,i,platformnames,rawfamilynames)
+                info[i] = getinfo(fontdata,i,platformnames,rawfamilynames,false,instancenames)
             end
             return info
         elseif subfont >= 1 and subfont <= #subfonts then
-            return getinfo(fontdata,subfont,platformnames,rawfamilynames)
+            return getinfo(fontdata,subfont,platformnames,rawfamilynames,false,instancenames)
         else
             return {
                 filename = filename,