rustybuzz/hb/
ot_layout_gsub_table.rs

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1use ttf_parser::gsub::*;
2use ttf_parser::opentype_layout::LookupIndex;
3use ttf_parser::GlyphId;
4
5use super::buffer::hb_buffer_t;
6use super::hb_font_t;
7use super::ot_layout::*;
8use super::ot_layout_common::{SubstLookup, SubstitutionTable};
9use super::ot_layout_gsubgpos::*;
10use super::ot_shape_plan::hb_ot_shape_plan_t;
11use OT::hb_ot_apply_context_t;
12
13pub fn substitute(plan: &hb_ot_shape_plan_t, face: &hb_font_t, buffer: &mut hb_buffer_t) {
14    apply_layout_table(plan, face, buffer, face.gsub.as_ref());
15}
16
17impl<'a> LayoutTable for SubstitutionTable<'a> {
18    const INDEX: TableIndex = TableIndex::GSUB;
19    const IN_PLACE: bool = false;
20
21    type Lookup = SubstLookup<'a>;
22
23    fn get_lookup(&self, index: LookupIndex) -> Option<&Self::Lookup> {
24        self.lookups.get(usize::from(index))
25    }
26}
27
28impl LayoutLookup for SubstLookup<'_> {
29    fn props(&self) -> u32 {
30        self.props
31    }
32
33    fn is_reverse(&self) -> bool {
34        self.reverse
35    }
36
37    fn covers(&self, glyph: GlyphId) -> bool {
38        self.coverage.contains(glyph)
39    }
40}
41
42impl WouldApply for SubstLookup<'_> {
43    fn would_apply(&self, ctx: &WouldApplyContext) -> bool {
44        self.covers(ctx.glyphs[0])
45            && self
46                .subtables
47                .iter()
48                .any(|subtable| subtable.would_apply(ctx))
49    }
50}
51
52impl Apply for SubstLookup<'_> {
53    fn apply(&self, ctx: &mut hb_ot_apply_context_t) -> Option<()> {
54        if self.covers(ctx.buffer.cur(0).as_glyph()) {
55            for subtable in &self.subtables {
56                if subtable.apply(ctx).is_some() {
57                    return Some(());
58                }
59            }
60        }
61
62        None
63    }
64}
65
66impl WouldApply for SubstitutionSubtable<'_> {
67    fn would_apply(&self, ctx: &WouldApplyContext) -> bool {
68        match self {
69            Self::Single(t) => t.would_apply(ctx),
70            Self::Multiple(t) => t.would_apply(ctx),
71            Self::Alternate(t) => t.would_apply(ctx),
72            Self::Ligature(t) => t.would_apply(ctx),
73            Self::Context(t) => t.would_apply(ctx),
74            Self::ChainContext(t) => t.would_apply(ctx),
75            Self::ReverseChainSingle(t) => t.would_apply(ctx),
76        }
77    }
78}
79
80impl Apply for SubstitutionSubtable<'_> {
81    fn apply(&self, ctx: &mut hb_ot_apply_context_t) -> Option<()> {
82        match self {
83            Self::Single(t) => t.apply(ctx),
84            Self::Multiple(t) => t.apply(ctx),
85            Self::Alternate(t) => t.apply(ctx),
86            Self::Ligature(t) => t.apply(ctx),
87            Self::Context(t) => t.apply(ctx),
88            Self::ChainContext(t) => t.apply(ctx),
89            Self::ReverseChainSingle(t) => t.apply(ctx),
90        }
91    }
92}
rustybuzz/hb/ot_layout_gsub_table.rs

rustybuzz/hb/
ot_layout_gsub_table.rs
