diff options
Diffstat (limited to 'tex/context/base/mkiv/scrp-eth.lua')
-rw-r--r-- | tex/context/base/mkiv/scrp-eth.lua | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/tex/context/base/mkiv/scrp-eth.lua b/tex/context/base/mkiv/scrp-eth.lua new file mode 100644 index 000000000..8ecbce522 --- /dev/null +++ b/tex/context/base/mkiv/scrp-eth.lua @@ -0,0 +1,158 @@ +if not modules then modules = { } end modules ['scrp-eth'] = { + version = 1.001, + comment = "companion to scrp-ini.mkiv", + author = "Hans Hagen, PRAGMA-ADE, Hasselt NL", + copyright = "PRAGMA ADE / ConTeXt Development Team", + license = "see context related readme files" +} + +-- at some point I will review the script code but for the moment we +-- do it this way; so space settings like with cjk yet + +local nuts = nodes.nuts + +local getnext = nuts.getnext +local getfont = nuts.getfont +local getchar = nuts.getchar +local getid = nuts.getid +local getattr = nuts.getattr + +local insert_node_before = nuts.insert_before + +local nodepool = nuts.pool + +local new_glue = nodepool.glue +local new_penalty = nodepool.penalty + +local nodecodes = nodes.nodecodes +local glyph_code = nodecodes.glyph + +local a_scriptstatus = attributes.private('scriptstatus') +local a_scriptinjection = attributes.private('scriptinjection') + +local categorytonumber = scripts.categorytonumber +local numbertocategory = scripts.numbertocategory +local hash = scripts.hash +local numbertodataset = scripts.numbertodataset + +local fonthashes = fonts.hashes +local parameters = fonthashes.parameters + +local space, stretch, shrink, lastfont + +local inter_character_space_factor = 1 +local inter_character_stretch_factor = 1 +local inter_character_shrink_factor = 1 + +local function space_glue(current) + local data = numbertodataset[getattr(current,a_scriptinjection)] + if data then + inter_character_space_factor = data.inter_character_space_factor or 1 + inter_character_stretch_factor = data.inter_character_stretch_factor or 1 + inter_character_shrink_factor = data.inter_character_shrink_factor or 1 + end + local font = getfont(current) + if lastfont ~= font then + local pf = parameters[font] + space = pf.space + stretch = pf.space_stretch + shrink = pf.space_shrink + lastfont = font + end + return new_glue( + inter_character_space_factor * space, + inter_character_stretch_factor * stretch, + inter_character_shrink_factor * shrink + ) +end + +local function insert_space(head,current) + insert_node_before(head,current,space_glue(current)) +end + +local function insert_zerowidthspace(head,current) + insert_node_before(head,current,new_glue(0)) +end + +local function insert_nobreakspace(head,current) + insert_node_before(head,current,new_penalty(10000)) + insert_node_before(head,current,space_glue(current)) +end + +-- syllable [zerowidthspace] syllable +-- syllable [zerowidthspace] word +-- syllable [zerowidthspace] sentence +-- word [nobreakspace] syllable +-- word [space] word +-- word [space] sentence +-- sentence [nobreakspace] syllable +-- sentence [space] word +-- sentence [space] sentence + +local injectors = { -- [previous] [current] + ethiopic_syllable = { + ethiopic_syllable = insert_zerowidthspace, + ethiopic_word = insert_nobreakspace, + ethiopic_sentence = insert_nobreakspace, + }, + ethiopic_word = { + ethiopic_syllable = insert_space, + ethiopic_word = insert_space, + ethiopic_sentence = insert_space, + }, + ethiopic_sentence = { + ethiopic_syllable = insert_space, + ethiopic_word = insert_space, + ethiopic_sentence = insert_space, + }, +} + +local function process(head,first,last) + if first ~= last then + local injector = false + local current = first + while current do + local id = getid(current) + if id == glyph_code then + local scriptstatus = getattr(current,a_scriptstatus) + local category = numbertocategory[scriptstatus] + if injector then + local action = injector[category] + if action then + action(head,current) + end + end + injector = injectors[category] + else + -- nothing yet + end + if current == last then + break + else + current = getnext(current) + end + end + end +end + +scripts.installmethod { + name = "ethiopic", + injector = process, + datasets = { + default = { + inter_character_space_factor = 1, + inter_character_stretch_factor = 1, + inter_character_shrink_factor = 1, + }, + half = { + inter_character_space_factor = 0.5, + inter_character_stretch_factor = 0.5, + inter_character_shrink_factor = 0.5, + }, + quarter = { + inter_character_space_factor = 0.25, + inter_character_stretch_factor = 0.25, + inter_character_shrink_factor = 0.25, + }, + }, +} |