font-map-core 0.2.9

Core font-parsing capabilities for font-map
Documentation 
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

#![allow(clippy::cast_possible_wrap)]
#![allow(clippy::cast_possible_truncation)]
use crate::error::ParseResult;
use crate::reader::{BinaryReader, Parse};

/// The Post table of a TrueType font  
/// Contains only the subset of the table needed for mapping glyph indices to glyph names
#[derive(Debug, Default)]
pub struct PostTable {
    /// True if the font is monospaced
    pub is_monospaced: bool,

    /// The glyph names in the table, by glyph index
    pub glyph_names: Vec<String>,
}

impl PostTable {
    /// Returns the name of the glyph at the specified index, if it exists
    #[must_use]
    pub fn get_glyph_name(&self, index: u16) -> Option<&str> {
        self.glyph_names.get(index as usize).map(String::as_str)
    }
}

impl Parse for PostTable {
    fn parse(reader: &mut BinaryReader) -> ParseResult<Self> {
        let mut table = Self::default();

        //
        // Table header
        let fmt = reader.read_fixed32()?;
        reader.skip_u32()?; // italic angle
        reader.skip_u16()?; // underline position
        reader.skip_u16()?; // underline thickness
        table.is_monospaced = reader.read_u32()? != 0; // is fixed pitch
        reader.skip_u32()?; // min memory t42
        reader.skip_u32()?; // max memory t42
        reader.skip_u32()?; // min memory t1
        reader.skip_u32()?; // max memory t1

        debug_msg!("  Format = {}.{}", fmt.0, fmt.1);

        match fmt {
            (1, 0) => {
                //
                // Format 1.0 uses the standard Macintosh character set
                table.glyph_names = POST_MAC_NAMES.iter().map(ToString::to_string).collect();
            }

            (2, 0) => {
                //
                // Format 2.0 uses a 32-bit offset to the glyph name
                let num_glyphs = reader.read_u16()?;
                debug_msg!("  Num glyphs = {}", num_glyphs);

                //
                // Read the glyph names first
                let mut names = Vec::with_capacity(num_glyphs as usize);
                let mut name_reader = reader.clone();
                name_reader.advance_by(num_glyphs as isize * 2)?;
                while !name_reader.is_eof() {
                    let len = name_reader.read_u8()?;
                    let name = name_reader.read_string(len as usize)?;
                    names.push(name);
                }

                for _ in 0..num_glyphs {
                    let ordinal = reader.read_u16()?;
                    if ordinal < POST_MAC_NAMES_LEN as u16 {
                        table
                            .glyph_names
                            .push(POST_MAC_NAMES[ordinal as usize].to_string());
                    } else {
                        let index = (ordinal - POST_MAC_NAMES_LEN as u16) as usize;
                        table.glyph_names.push(names[index].clone());
                    }
                }
            }

            (2, 5) => {
                //
                // Format 2.5 uses an 8-bit offset to the std glyph names
                let num_glyphs = reader.read_u16()?;

                let mut glyph_names = Vec::new();
                for i in 0..num_glyphs {
                    let offset = reader.read_i8()?;
                    let index = i.wrapping_add_signed(i16::from(offset));
                    glyph_names.push(POST_MAC_NAMES[index as usize].to_string());
                }
            }

            _ => {
                // Other formats are not useful to us here
            }
        }

        debug_msg!("  Found {} glyph names", table.glyph_names.len());
        Ok(table)
    }
}

//
// Standard Macintosh glyph names
const POST_MAC_NAMES_LEN: usize = 258;
#[rustfmt::skip]
const POST_MAC_NAMES: [&str; POST_MAC_NAMES_LEN] = [
    ".notdef", ".null", "nonmarkingreturn", "space", "exclam", "quotedbl", "numbersign", "dollar", "percent", 
    "ampersand", "quotesingle","parenleft","parenright","asterisk","plus","comma", "hyphen", "period", "slash", 
    "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "colon", "semicolon", "less",
    "equal", "greater", "question", "at", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", 
    "O",  "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "bracketleft", "backslash", "bracketright", "asciicircum", 
    "underscore", "grave", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", 
    "s", "t", "u", "v", "w", "x", "y", "z", "braceleft", "bar", "braceright", "asciitilde", "Adieresis", "Aring", 
    "Ccedilla", "Eacute", "Ntilde", "Odieresis", "Udieresis", "aacute", "agrave", "acircumflex", "adieresis", 
    "atilde", "aring", "ccedilla", "eacute", "egrave", "ecircumflex", "edieresis", "iacute", "igrave",
    "icircumflex", "idieresis", "ntilde", "oacute", "ograve", "ocircumflex", "odieresis", "otilde", "uacute", "ugrave", 
    "ucircumflex", "udieresis", "dagger", "degree", "cent", "sterling", "section", "bullet", "paragraph", "germandbls", 
    "registered", "copyright", "trademark", "acute", "dieresis", "notequal", "AE", "Oslash", "infinity", "plusminus", 
    "lessequal", "greaterequal", "yen", "mu", "partialdiff", "summation", "product", "pi", "integral", "ordfeminine", 
    "ordmasculine", "Omega", "ae", "oslash", "questiondown", "exclamdown", "logicalnot", "radical", "florin", "approxequal", 
    "Delta", "guillemotleft", "guillemotright", "ellipsis", "nonbreakingspace", "Agrave", "Atilde", "Otilde", "OE", "oe", 
    "endash", "emdash", "quotedblleft", "quotedblright", "quoteleft", "quoteright", "divide", "lozenge", "ydieresis", 
    "Ydieresis", "fraction", "currency", "guilsinglleft", "guilsinglright", "fi", "fl", "daggerdbl", "periodcentered", 
    "quotesinglbase", "quotedblbase", "perthousand", "Acircumflex", "Ecircumflex", "Aacute", "Edieresis", "Egrave", 
    "Iacute", "Icircumflex", "Idieresis", "Igrave", "Oacute", "Ocircumflex", "apple", "Ograve", "Uacute", "Ucircumflex", 
    "Ugrave", "dotlessi", "circumflex", "tilde", "macron", "breve", "dotaccent", "ring", "cedilla", "hungarumlaut", 
    "ogonek", "caron", "Lslash", "lslash", "Scaron", "scaron", "Zcaron", "zcaron", "brokenbar", "Eth", "eth", "Yacute", 
    "yacute", "Thorn", "thorn", "minus", "multiply", "onesuperior", "twosuperior", "threesuperior", "onehalf", "onequarter", 
    "threequarters", "franc", "Gbreve", "gbreve", "Idotaccent", "Scedilla", "scedilla", "Cacute", "cacute", "Ccaron", 
    "ccaron", "dcroat"
];