summaryrefslogtreecommitdiff
path: root/data/charwidths.jl
blob: 72d695fc01d84d05c062de75bf62e42d046542cb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
# Following work by @jiahao, we compute character widths using a combination of
#   * advance widths from GNU Unifont (advance width 512 = 1 en)
#   * UAX 11: East Asian Width
#   * a few exceptions as needed
# Adapted from http://nbviewer.ipython.org/gist/jiahao/07e8b08bf6d8671e9734
#
# Requires Julia (obviously) and FontForge.

#############################################################################
# Julia 0.3/0.4 compatibility (taken from Compat package)
if VERSION < v"0.4.0-dev+1419"
    const UInt16 = Uint16
end

CharWidths = Dict{Int,Int}()

#############################################################################
# Widths from GNU Unifont

universion=get(ENV, "UNIFONT_VERSION", "7.0.06")
for fontfile in ["unifont-$universion", "unifont_upper-$universion"]
    isfile("$fontfile.ttf") || download("http://unifoundry.com/pub/unifont-$universion/font-builds/$fontfile.ttf", "$fontfile.ttf")
    isfile("$fontfile.sfd") || run(`fontforge -lang=ff -c "Open(\"$fontfile.ttf\");Save(\"$fontfile.sfd\");Quit(0);"`)
end

#Read sfdfile for character widths
function parsesfd(filename::String, CharWidths::Dict{Int,Int}=Dict{Int,Int}())
    state=:seekchar
    lineno = 0
    for line in readlines(open(filename))
        lineno += 1
        if state==:seekchar         #StartChar: nonmarkingreturn
            if contains(line, "StartChar: ")
                codepoint = nothing
                width = nothing
                state = :readdata
            end
        elseif state==:readdata #Encoding: 65538 -1 2, Width: 1024
            contains(line, "Encoding:") && (codepoint = int(split(line)[3]))
            contains(line, "Width:") && (width = int(split(line)[2]))
            if codepoint!=nothing && width!=nothing && codepoint >= 0
                CharWidths[codepoint]=div(width, 512) # 512 units to the en
                state = :seekchar
            end
        end
    end
    CharWidths
end
CharWidths=parsesfd("unifont-$universion.sfd", CharWidths)
CharWidths=parsesfd("unifont_upper-$universion.sfd", CharWidths)

#############################################################################
# Widths from UAX #11: East Asian Width
#   .. these take precedence over the Unifont width for all codepoints
#      listed explicitly as wide/full/narrow/half-width

isfile("EastAsianWidth.txt") || download("http://www.unicode.org/Public/UNIDATA/EastAsianWidth.txt", "EastAsianWidth.txt")
for line in readlines(open("EastAsianWidth.txt"))
    #Strip comments
    line[1] == '#' && continue
    precomment = split(line, '#')[1]
    #Parse code point range and width code
    tokens = split(precomment, ';')
    length(tokens) >= 2 || continue
    charrange = tokens[1]
    width = strip(tokens[2])
    #Parse code point range into Julia UnitRange
    rangetokens = split(charrange, "..")
    charstart = uint32("0x"*rangetokens[1])
    charend = uint32("0x"*rangetokens[length(rangetokens)>1 ? 2 : 1])

    #Assign widths
    for c in charstart:charend
        if width=="W" || width=="F" # wide or full
            CharWidths[c]=2
        elseif width=="Na"|| width=="H" # narrow or half
            CharWidths[c]=1
        end
    end
end

#############################################################################
# A few exceptions to the above cases, found by manual comparison
# to other wcwidth functions and similar checks.

# Use ../libutf8proc for category codes, rather than the one in Julia,
# to minimize bootstrapping complexity when a new version of Unicode comes out.
function catcode(c)
    uint(c) > 0x10FFFF && return 0x0000 # see utf8proc_get_property docs
    return unsafe_load(ccall((:utf8proc_get_property,"../libutf8proc"), Ptr{UInt16}, (Int32,), c))
end

# use Base.UTF8proc module to get category codes constants, since
# we aren't goint to change these in utf8proc.
import Base.UTF8proc

for c in keys(CharWidths)
    cat = catcode(c)

    # make sure format control character (category Cf) have width 0,
    # except for the Arabic characters 0x06xx (see unicode std 6.2, sec. 8.2)
    if cat==UTF8proc.UTF8PROC_CATEGORY_CF && c  [0x0601,0x0602,0x0603,0x06dd]
        CharWidths[c]=0
    end

    # Unifont has nonzero width for a number of non-spacing combining
    # characters, e.g. (in 7.0.06): f84,17b4,17b5,180b,180d,2d7f, and
    # the variation selectors
    if cat==UTF8proc.UTF8PROC_CATEGORY_MN
        CharWidths[c]=0
    end

    # We also assign width of zero to unassigned and private-use
    # codepoints (Unifont includes ConScript Unicode Registry PUA fonts,
    # but since these are nonstandard it seems questionable to recognize them).
    if cat==UTF8proc.UTF8PROC_CATEGORY_CO || cat==UTF8proc.UTF8PROC_CATEGORY_CN
        CharWidths[c]=0
    end
    
    # for some reason, Unifont has width-2 glyphs for ASCII control chars
    if cat==UTF8proc.UTF8PROC_CATEGORY_CC
        CharWidths[c]=0
    end
end

#By definition, should have zero width (on the same line)
#0x002028 '
' category: Zl name: LINE SEPARATOR/
#0x002029 '
' category: Zp name: PARAGRAPH SEPARATOR/
CharWidths[0x2028]=0
CharWidths[0x2029]=0

#By definition, should be narrow = width of 1 en space
#0x00202f ' ' category: Zs name: NARROW NO-BREAK SPACE/
CharWidths[0x202f]=1

#By definition, should be wide = width of 1 em space
#0x002001 ' ' category: Zs name: EM QUAD/
#0x002003 ' ' category: Zs name: EM SPACE/
CharWidths[0x2001]=2
CharWidths[0x2003]=2

#############################################################################
# Output (to a file or pipe) for processing by data_generator.rb
# ... don't bother to output zero widths since that will be the default.

firstc = 0x000000
lastv = 0
uhex(c) = uppercase(hex(c,4))
for c in 0x0000:0x110000
    v = get(CharWidths, c, 0)
    if v != lastv || c == 0x110000
        v < 4 || error("invalid charwidth $v for $c")
        if firstc+1 < c
            println(uhex(firstc), "..", uhex(c-1), "; ", lastv)
        else
            println(uhex(firstc), "; ", lastv)
        end
        firstc = c
        lastv = v
    end
end