ttf_parser/tables/
vhea.rs

1// https://docs.microsoft.com/en-us/typography/opentype/spec/vhea
2
3use core::num::NonZeroU16;
4
5use crate::parser::Stream;
6
7
8const TABLE_SIZE: usize = 36;
9const ASCENDER_OFFSET: usize = 4;
10const DESCENDER_OFFSET: usize = 6;
11const LINE_GAP_OFFSET: usize = 8;
12const NUM_OF_LONG_VER_METRICS_OFFSET: usize = 34;
13
14
15#[inline]
16pub fn parse(data: &[u8]) -> Option<&[u8]> {
17    if data.len() == TABLE_SIZE {
18        Some(data)
19    } else {
20        None
21    }
22}
23
24#[inline]
25pub fn ascender(data: &[u8]) -> i16 {
26    Stream::read_at::<i16>(data, ASCENDER_OFFSET).unwrap_or(0)
27}
28
29#[inline]
30pub fn descender(data: &[u8]) -> i16 {
31    Stream::read_at::<i16>(data, DESCENDER_OFFSET).unwrap_or(0)
32}
33
34#[inline]
35pub fn line_gap(data: &[u8]) -> i16 {
36    Stream::read_at::<i16>(data, LINE_GAP_OFFSET).unwrap_or(0)
37}
38
39#[inline]
40pub fn num_of_long_ver_metrics(data: &[u8]) -> Option<NonZeroU16> {
41    Stream::read_at::<u16>(data, NUM_OF_LONG_VER_METRICS_OFFSET).and_then(NonZeroU16::new)
42}