harfrust 0.5.2

A complete HarfBuzz shaping algorithm port to Rust.
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

use super::buffer::*;
use super::ot_shape_plan::hb_ot_shape_plan_t;
use super::{hb_font_t, GlyphInfo};
use crate::BufferFlags;

pub fn insert_dotted_circles(
    face: &hb_font_t,
    buffer: &mut hb_buffer_t,
    broken_syllable_type: u8,
    dottedcircle_category: u8,
    repha_category: Option<u8>,
    dottedcircle_position: Option<u8>,
) -> bool {
    if buffer
        .flags
        .contains(BufferFlags::DO_NOT_INSERT_DOTTED_CIRCLE)
    {
        return false;
    }

    if (buffer.scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_BROKEN_SYLLABLE) == 0 {
        return false;
    }

    let dottedcircle_glyph = match face.get_nominal_glyph(0x25CC) {
        Some(g) => g.to_u32(),
        None => return false,
    };

    let mut dottedcircle = GlyphInfo {
        glyph_id: 0x25CC,
        ..GlyphInfo::default()
    };
    dottedcircle.set_ot_shaper_var_u8_category(dottedcircle_category);
    if let Some(dottedcircle_position) = dottedcircle_position {
        dottedcircle.set_ot_shaper_var_u8_auxiliary(dottedcircle_position);
    }
    dottedcircle.glyph_id = dottedcircle_glyph;

    buffer.clear_output();

    buffer.idx = 0;
    let mut last_syllable = 0;
    while buffer.idx < buffer.len {
        let syllable = buffer.cur(0).syllable();
        if last_syllable != syllable && (syllable & 0x0F) == broken_syllable_type {
            last_syllable = syllable;

            let mut ginfo = dottedcircle;
            ginfo.cluster = buffer.cur(0).cluster;
            ginfo.mask = buffer.cur(0).mask;
            ginfo.set_syllable(buffer.cur(0).syllable());

            // Insert dottedcircle after possible Repha.
            if let Some(repha_category) = repha_category {
                while buffer.idx < buffer.len
                    && last_syllable == buffer.cur(0).syllable()
                    && buffer.cur(0).ot_shaper_var_u8_category() == repha_category
                {
                    buffer.next_glyph();
                }
            }

            buffer.output_info(ginfo);
        } else {
            buffer.next_glyph();
        }
    }

    buffer.sync();

    true
}

pub(crate) fn syllabic_clear_var(
    _: &hb_ot_shape_plan_t,
    _: &hb_font_t,
    buffer: &mut hb_buffer_t,
) -> bool {
    for info in &mut buffer.info {
        info.set_syllable(0);
    }
    buffer.deallocate_var(GlyphInfo::SYLLABLE_VAR);

    false
}