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path: root/src/fontloader/misc/fontloader-font-ots.lua
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Diffstat (limited to 'src/fontloader/misc/fontloader-font-ots.lua')
-rw-r--r--src/fontloader/misc/fontloader-font-ots.lua271
1 files changed, 102 insertions, 169 deletions
diff --git a/src/fontloader/misc/fontloader-font-ots.lua b/src/fontloader/misc/fontloader-font-ots.lua
index 51704bf..d63d524 100644
--- a/src/fontloader/misc/fontloader-font-ots.lua
+++ b/src/fontloader/misc/fontloader-font-ots.lua
@@ -192,6 +192,7 @@ local free_node = nuts.free
local end_of_math = nuts.end_of_math
local traverse_nodes = nuts.traverse
local traverse_id = nuts.traverse_id
+local remove_node = nuts.remove
local setmetatableindex = table.setmetatableindex
@@ -1236,7 +1237,7 @@ function chainprocs.gsub_multiple(head,start,stop,dataset,sequence,currentlookup
if trace_multiples then
logprocess("%s: replacing %s by multiple characters %s",cref(dataset,sequence),gref(startchar),gref(replacement))
end
- return multiple_glyphs(head,start,replacement,currentlookup.flags[1]) -- not sequence.flags?
+ return multiple_glyphs(head,start,replacement,sequence.flags[1])
end
return head, start, false
end
@@ -2033,67 +2034,6 @@ local function chaindisk(head,start,last,dataset,sequence,chainlookup,rlmode,k,c
return head, start, ok
end
--- helpers from elsewhere
-
--- local function currentmatch(current,n,l)
--- while current do
--- if getid(current) ~= glyph_code then
--- return false
--- elseif seq[n][getchar(current)] then
--- n = n + 1
--- current = getnext(current)
--- if not current then
--- return true, n, current
--- elseif n > l then
--- -- match = false
--- return true, n, current
--- end
--- else
--- return false
--- end
--- end
--- end
---
--- local function aftermatch(current,n,l)
--- while current do
--- if getid(current) ~= glyph_code then
--- return false
--- elseif seq[n][getchar(current)] then
--- n = n + 1
--- current = getnext(current)
--- if not current then
--- return true, n, current
--- elseif n > l then
--- -- match = false
--- return true, n, current
--- end
--- else
--- return false
--- end
--- end
--- end
---
--- local function beforematch(current,n)
--- local finish = getprev(current)
--- local current = find_node_tail(current)
--- while current do
--- if getid(current) ~= glyph_code then
--- return false
--- elseif seq[n][getchar(current)] then
--- n = n - 1
--- current = getprev(current)
--- if not current or current == finish then
--- return true, n, current
--- elseif n < 1 then
--- -- match = false
--- return true, n, current
--- end
--- else
--- return false
--- end
--- end
--- end
-
local noflags = { false, false, false, false }
local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
@@ -2116,9 +2056,10 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
local ck = contexts[k]
local seq = ck[3]
local s = #seq
+ local size = 1
-- f..l = mid string
if s == 1 then
- -- never happens
+ -- this seldom happens as it makes no sense (bril, ebgaramond, husayni, minion)
local char = ischar(current,currentfont)
if char then
match = seq[1][char]
@@ -2129,48 +2070,34 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
local f = ck[4]
local l = 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 discfound = nil
- local n = f + 1
- last = getnext(last) -- the second in current (first already matched)
- while n <= l do
- if not last and (sweeptype == "post" or sweeptype == "replace") then
- last = getnext(sweepnode)
- sweeptype = nil
- end
- if last then
- local char, id = ischar(last,currentfont)
- if char then
- local ccd = descriptions[char]
- if ccd then
- local class = ccd.class or "base"
- 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(dataset,sequence,char,ck,class)
- end
+ size = l - f + 1
+ if size > 1 then
+ -- before/current/after | before/current | current/after
+ local discfound = nil
+ local n = f + 1
+ last = getnext(last) -- the second in current (first already matched)
+ while n <= l do
+ if not last and (sweeptype == "post" or sweeptype == "replace") then
+ last = getnext(sweepnode)
+ sweeptype = nil
+ end
+ if last then
+ local char, id = ischar(last,currentfont)
+ if char then
+ local ccd = descriptions[char]
+ if ccd then
+ local class = ccd.class or "base"
+ 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(dataset,sequence,char,ck,class)
+ end
+ last = getnext(last)
+ elseif seq[n][char] then
+ if n < l then
last = getnext(last)
- elseif seq[n][char] then
- if n < l then
- last = getnext(last)
- end
- n = n + 1
- else
- if discfound then
- notmatchreplace[discfound] = true
- match = not notmatchpre[discfound]
- else
- match = false
- end
- break
end
+ n = n + 1
else
if discfound then
notmatchreplace[discfound] = true
@@ -2180,7 +2107,7 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
end
break
end
- elseif char == false then
+ else
if discfound then
notmatchreplace[discfound] = true
match = not notmatchpre[discfound]
@@ -2188,60 +2115,68 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
match = false
end
break
- elseif id == disc_code then
- diskseen = true
- discfound = last
- notmatchpre[last] = nil
- notmatchpost[last] = true
- notmatchreplace[last] = nil
- local pre, post, replace = getdisc(last)
- if pre then
- local n = n
- while pre do
- if seq[n][getchar(pre)] then
- n = n + 1
- pre = getnext(pre)
- if n > l then
- break
- end
- else
- notmatchpre[last] = true
+ end
+ elseif char == false then
+ if discfound then
+ notmatchreplace[discfound] = true
+ match = not notmatchpre[discfound]
+ else
+ match = false
+ end
+ break
+ elseif id == disc_code then
+ diskseen = true
+ discfound = last
+ notmatchpre[last] = nil
+ notmatchpost[last] = true
+ notmatchreplace[last] = nil
+ local pre, post, replace = getdisc(last)
+ if pre then
+ local n = n
+ while pre do
+ if seq[n][getchar(pre)] then
+ n = n + 1
+ pre = getnext(pre)
+ if n > l then
break
end
- end
- if n <= l then
+ else
notmatchpre[last] = true
+ break
end
- else
+ end
+ if n <= l then
notmatchpre[last] = true
end
- if replace then
- -- so far we never entered this branch
- while replace do
- if seq[n][getchar(replace)] then
- n = n + 1
- replace = getnext(replace)
- if n > l then
- break
- end
- else
- notmatchreplace[last] = true
- match = not notmatchpre[last]
+ else
+ notmatchpre[last] = true
+ end
+ if replace then
+ -- so far we never entered this branch
+ while replace do
+ if seq[n][getchar(replace)] then
+ n = n + 1
+ replace = getnext(replace)
+ if n > l then
break
end
+ else
+ notmatchreplace[last] = true
+ match = not notmatchpre[last]
+ break
end
- match = not notmatchpre[last]
end
- -- maybe only if match
- last = getnext(last)
- else
- match = false
- break
+ match = not notmatchpre[last]
end
+ -- maybe only if match
+ last = getnext(last)
else
match = false
break
end
+ else
+ match = false
+ break
end
end
end
@@ -2509,7 +2444,7 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
end
end
if match then
- -- can lookups be of a different type ?
+ -- Can lookups be of a different type?
local diskchain = diskseen or sweepnode
if trace_contexts then
local rule = ck[1]
@@ -2523,8 +2458,12 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
local chainlookups = ck[6]
if chainlookups then
local nofchainlookups = #chainlookups
- -- we can speed this up if needed
- if nofchainlookups == 1 then
+ -- Lookups can be like { 1, false, 3 } or { false, 2 } or basically anything and
+ -- #lookups can be less than #current
+ if size == 1 then
+ -- if nofchainlookups > size then
+ -- -- bad rules
+ -- end
local chainlookup = chainlookups[1]
local chainkind = chainlookup.type
local chainproc = chainprocs[chainkind]
@@ -2542,8 +2481,16 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
logprocess("%s: %s is not yet supported (1)",cref(dataset,sequence),chainkind)
end
else
+ -- See LookupType 5: Contextual Substitution Subtable. Now it becomes messy. The
+ -- easiest case is where #current maps on #lookups i.e. one-to-one. But what if
+ -- we have a ligature. Cf the spec we then need to advance one character but we
+ -- really need to test it as there are fonts out there that are fuzzy and have
+ -- too many lookups:
+ --
+ -- U+1105 U+119E U+1105 U+119E : sourcehansansklight: script=hang ccmp=yes
+ --
local i = 1
- while start and true do
+ while start do
if skipped then
while start do -- todo: use properties
local char = getchar(start)
@@ -2560,12 +2507,8 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
end
end
end
- -- see remark in ms standard under : LookupType 5: Contextual Substitution Subtable
- local chainlookup = chainlookups[1] -- should be i when they can be different
- if not chainlookup then
- -- we just advance
- i = i + 1 -- shouldn't that be #current
- else
+ local chainlookup = chainlookups[i]
+ if chainlookup then
local chainkind = chainlookup.type
local chainproc = chainprocs[chainkind]
if chainproc then
@@ -2578,29 +2521,18 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
-- messy since last can be changed !
if ok then
done = true
- if n and n > 1 then
- -- we have a ligature (cf the spec we advance one but we really need to test it
- -- as there are fonts out there that are fuzzy and have too many lookups:
- --
- -- U+1105 U+119E U+1105 U+119E : sourcehansansklight: script=hang ccmp=yes
- --
- if i + n > nofchainlookups then
- -- if trace_contexts then
- -- logprocess("%s: quitting lookups",cref(dataset,sequence))
- -- end
- break
- else
- -- we need to carry one
- end
+ if n and n > 1 and i + n > nofchainlookups then
+ -- this is a safeguard, we just ignore the rest of the lookups
+ break
end
end
else
-- actually an error
logprocess("%s: %s is not yet supported (2)",cref(dataset,sequence),chainkind)
end
- i = i + 1
end
- if i > nofchainlookups or not start then
+ i = i + 1
+ if i > size or not start then
break
elseif start then
start = getnext(start)
@@ -2608,6 +2540,7 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
end
end
else
+ -- todo: needs checking for holes in the replacements
local replacements = ck[7]
if replacements then
head, start, done = reversesub(head,start,last,dataset,sequence,replacements,rlmode)