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
//! An [SVG Table](https://docs.microsoft.com/en-us/typography/opentype/spec/svg) implementation.

use crate::GlyphId;
use crate::parser::{FromData, LazyArray16, NumFrom, Offset, Offset32, Stream};

#[derive(Clone, Copy)]
struct SvgDocumentRecord {
    start_glyph_id: GlyphId,
    end_glyph_id: GlyphId,
    svg_doc_offset: Option<Offset32>,
    svg_doc_length: u32,
}

impl FromData for SvgDocumentRecord {
    const SIZE: usize = 12;

    #[inline]
    fn parse(data: &[u8]) -> Option<Self> {
        let mut s = Stream::new(data);
        Some(SvgDocumentRecord {
            start_glyph_id: s.read::<GlyphId>()?,
            end_glyph_id: s.read::<GlyphId>()?,
            svg_doc_offset: s.read::<Option<Offset32>>()?,
            svg_doc_length: s.read::<u32>()?,
        })
    }
}


/// A list of [SVG documents](
/// https://docs.microsoft.com/en-us/typography/opentype/spec/svg#svg-document-list).
#[derive(Clone, Copy)]
pub struct SvgDocumentsList<'a> {
    data: &'a [u8],
    records: LazyArray16<'a, SvgDocumentRecord>,
}

impl<'a> SvgDocumentsList<'a> {
    /// Returns SVG document data at index.
    ///
    /// `index` is not a GlyphId. You should use [`find()`](SvgDocumentsList::find) instead.
    #[inline]
    pub fn get(&self, index: u16) -> Option<&'a [u8]> {
        let record = self.records.get(index)?;
        let offset = record.svg_doc_offset?.to_usize();
        self.data.get(offset..offset + usize::num_from(record.svg_doc_length))
    }

    /// Returns a SVG document data by glyph ID.
    #[inline]
    pub fn find(&self, glyph_id: GlyphId) -> Option<&'a [u8]> {
        let index = self.records.into_iter()
            .position(|v| (v.start_glyph_id..=v.end_glyph_id).contains(&glyph_id))?;
        self.get(index as u16)
    }

    /// Returns the number of SVG documents in the list.
    pub fn len(&self) -> u16 {
        self.records.len()
    }
}

impl core::fmt::Debug for SvgDocumentsList<'_> {
    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
        write!(f, "SvgDocumentsList {{ ... }}")
    }
}

impl<'a> IntoIterator for SvgDocumentsList<'a,> {
    type Item = &'a [u8];
    type IntoIter = SvgDocumentsListIter<'a>;

    #[inline]
    fn into_iter(self) -> Self::IntoIter {
        SvgDocumentsListIter {
            list: self,
            index: 0,
        }
    }
}


/// An iterator over [`SvgDocumentsList`] values.
#[derive(Clone, Copy)]
#[allow(missing_debug_implementations)]
pub struct SvgDocumentsListIter<'a> {
    list: SvgDocumentsList<'a>,
    index: u16,
}

impl<'a> Iterator for SvgDocumentsListIter<'a> {
    type Item = &'a [u8];

    #[inline]
    fn next(&mut self) -> Option<Self::Item> {
        if self.index < self.list.len() {
            self.index += 1;
            self.list.get(self.index - 1)
        } else {
            None
        }
    }

    #[inline]
    fn count(self) -> usize {
        usize::from(self.list.len().checked_sub(self.index).unwrap_or(0))
    }
}


/// An [SVG Table](https://docs.microsoft.com/en-us/typography/opentype/spec/svg).
#[derive(Clone, Copy, Debug)]
pub struct Table<'a> {
    /// A list of SVG documents.
    pub documents: SvgDocumentsList<'a>,
}

impl<'a> Table<'a> {
    /// Parses a table from raw data.
    pub fn parse(data: &'a [u8]) -> Option<Self> {
        let mut s = Stream::new(data);
        s.skip::<u16>(); // version
        let doc_list_offset = s.read::<Option<Offset32>>()??;

        let mut s = Stream::new_at(data, doc_list_offset.to_usize())?;
        let count = s.read::<u16>()?;
        let records = s.read_array16::<SvgDocumentRecord>(count)?;

        Some(Table {
            documents: SvgDocumentsList {
                data: &data[doc_list_offset.0 as usize..],
                records,
            }
        })
    }
}