use crate::{
layout::intersected_glyphs_and_indices,
offset::SerializeSerialize,
serialize::{SerializeErrorFlags, Serializer},
Plan, Serialize, SubsetState, SubsetTable,
};
use fnv::FnvHashMap;
use fontcull_write_fonts::{
read::{
tables::{
gsub::{SingleSubst, SingleSubstFormat1, SingleSubstFormat2},
layout::CoverageTable,
},
types::GlyphId,
FontRef,
},
types::Offset16,
};
impl<'a> SubsetTable<'a> for SingleSubst<'_> {
type ArgsForSubset = (&'a SubsetState, &'a FontRef<'a>, &'a FnvHashMap<u16, u16>);
type Output = ();
fn subset(
&self,
plan: &Plan,
s: &mut Serializer,
_args: Self::ArgsForSubset,
) -> Result<Self::Output, SerializeErrorFlags> {
match self {
Self::Format1(item) => item.subset(plan, s, ()),
Self::Format2(item) => item.subset(plan, s, ()),
}
}
}
impl<'a> SubsetTable<'a> for SingleSubstFormat1<'_> {
type ArgsForSubset = ();
type Output = ();
fn subset(
&self,
plan: &Plan,
s: &mut Serializer,
_args: Self::ArgsForSubset,
) -> Result<Self::Output, SerializeErrorFlags> {
let coverage = self
.coverage()
.map_err(|_| s.set_err(SerializeErrorFlags::SERIALIZE_ERROR_READ_ERROR))?;
let cov_glyphs = coverage.intersect_set(&plan.glyphset_gsub);
let delta = self.delta_glyph_id() as i32;
let glyph_map = &plan.glyph_map_gsub;
if cov_glyphs.is_empty() {
return Err(SerializeErrorFlags::SERIALIZE_ERROR_EMPTY);
}
let cap = cov_glyphs.len() as usize;
let mut retained_glyphs = Vec::with_capacity(cap);
let mut sub_glyphs = Vec::with_capacity(cap);
for (new_g, new_sub_g) in cov_glyphs
.iter()
.map(|g| (g, GlyphId::from(g.to_u32().wrapping_add_signed(delta))))
.filter_map(|(g, sub_g)| {
let new_g = glyph_map.get(&g)?;
let new_sub_g = glyph_map.get(&sub_g)?;
Some((*new_g, *new_sub_g))
})
{
retained_glyphs.push(new_g);
sub_glyphs.push(new_sub_g);
}
if retained_glyphs.is_empty() {
return Err(SerializeErrorFlags::SERIALIZE_ERROR_EMPTY);
}
SingleSubst::serialize(s, (&retained_glyphs, &sub_glyphs))
}
}
impl<'a> SubsetTable<'a> for SingleSubstFormat2<'_> {
type ArgsForSubset = ();
type Output = ();
fn subset(
&self,
plan: &Plan,
s: &mut Serializer,
_args: Self::ArgsForSubset,
) -> Result<Self::Output, SerializeErrorFlags> {
let coverage = self
.coverage()
.map_err(|_| s.set_err(SerializeErrorFlags::SERIALIZE_ERROR_READ_ERROR))?;
let glyph_map = &plan.glyph_map_gsub;
let (cov_glyphs, glyph_idxes) =
intersected_glyphs_and_indices(&coverage, &plan.glyphset_gsub, glyph_map);
if cov_glyphs.is_empty() {
return Err(SerializeErrorFlags::SERIALIZE_ERROR_EMPTY);
}
let cap = cov_glyphs.len();
let mut retained_glyphs = Vec::with_capacity(cap);
let mut sub_glyphs = Vec::with_capacity(cap);
let sub_glyph_ids = self.substitute_glyph_ids();
for (new_g, new_sub_g) in
cov_glyphs
.iter()
.zip(glyph_idxes.iter())
.filter_map(|(new_g, idx)| {
let sub_g = sub_glyph_ids.get(idx as usize)?;
let new_sub_g = glyph_map.get(&GlyphId::from(sub_g.get()))?;
Some((*new_g, *new_sub_g))
})
{
retained_glyphs.push(new_g);
sub_glyphs.push(new_sub_g);
}
if retained_glyphs.is_empty() {
return Err(SerializeErrorFlags::SERIALIZE_ERROR_EMPTY);
}
SingleSubst::serialize(s, (&retained_glyphs, &sub_glyphs))
}
}
impl<'a> Serialize<'a> for SingleSubst<'_> {
type Args = (&'a [GlyphId], &'a [GlyphId]);
fn serialize(s: &mut Serializer, args: Self::Args) -> Result<(), SerializeErrorFlags> {
let (glyphs, sub_glyphs) = args;
if glyphs.len() != sub_glyphs.len() {
return Err(SerializeErrorFlags::SERIALIZE_ERROR_OTHER);
}
let delta = sub_glyphs[0].to_u32() as i32 - glyphs[0].to_u32() as i32;
if glyphs
.iter()
.zip(sub_glyphs)
.skip(1)
.all(|(g, sub_g)| sub_g.to_u32() as i32 - g.to_u32() as i32 == delta)
{
SingleSubstFormat1::serialize(s, (glyphs, delta as i16))
} else {
SingleSubstFormat2::serialize(s, (glyphs, sub_glyphs))
}
}
}
impl<'a> Serialize<'a> for SingleSubstFormat1<'_> {
type Args = (&'a [GlyphId], i16);
fn serialize(s: &mut Serializer, args: Self::Args) -> Result<(), SerializeErrorFlags> {
s.embed(1_u16)?;
let cov_offset_pos = s.embed(0_u16)?;
let (cov_glyphs, delta) = args;
Offset16::serialize_serialize::<CoverageTable>(s, cov_glyphs, cov_offset_pos)?;
s.embed(delta).map(|_| ())
}
}
impl<'a> Serialize<'a> for SingleSubstFormat2<'_> {
type Args = (&'a [GlyphId], &'a [GlyphId]);
fn serialize(s: &mut Serializer, args: Self::Args) -> Result<(), SerializeErrorFlags> {
s.embed(2_u16)?;
let cov_offset_pos = s.embed(0_u16)?;
let (cov_glyphs, sub_glyphs) = args;
let count = cov_glyphs.len();
if sub_glyphs.len() != count {
return Err(SerializeErrorFlags::SERIALIZE_ERROR_OTHER);
}
s.embed(count as u16)?;
let mut pos = s.allocate_size(2 * count, false)?;
for g in sub_glyphs {
let g = g.to_u32() as u16;
s.copy_assign(pos, g);
pos += 2;
}
Offset16::serialize_serialize::<CoverageTable>(s, cov_glyphs, cov_offset_pos)
}
}
#[cfg(test)]
mod test {
use super::*;
use fontcull_write_fonts::read::{types::GlyphId, FontRef, TableProvider};
#[test]
fn test_subset_single_subst_format1() {
use fontcull_write_fonts::read::tables::gsub::SubstitutionSubtables;
let font =
FontRef::new(include_bytes!("../../test-data/fonts/Roboto-Regular.ttf")).unwrap();
let gsub_lookups = font.gsub().unwrap().lookup_list().unwrap();
let lookup = gsub_lookups.lookups().get(5).unwrap();
let SubstitutionSubtables::Single(sub_tables) = lookup.subtables().unwrap() else {
panic!("Wrong type of lookup table!");
};
let singlesubst_table = sub_tables.get(0).unwrap();
let mut plan = Plan::default();
plan.glyph_map_gsub
.insert(GlyphId::from(777_u32), GlyphId::from(5_u32));
plan.glyph_map_gsub
.insert(GlyphId::from(779_u32), GlyphId::from(6_u32));
plan.glyphset_gsub.insert(GlyphId::from(777_u32));
plan.glyphset_gsub.insert(GlyphId::from(779_u32));
let mut s = Serializer::new(1024);
assert_eq!(s.start_serialize(), Ok(()));
let subset_state = SubsetState::default();
singlesubst_table
.subset(&plan, &mut s, (&subset_state, &font, &plan.gsub_lookups))
.unwrap();
assert!(!s.in_error());
s.end_serialize();
let subsetted_data = s.copy_bytes();
let expected_data: [u8; 12] = [
0x00, 0x01, 0x00, 0x06, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00, 0x05,
];
assert_eq!(subsetted_data, expected_data);
}
#[test]
fn test_subset_single_subst_format2() {
use fontcull_write_fonts::read::tables::gsub::SubstitutionSubtables;
let font =
FontRef::new(include_bytes!("../../test-data/fonts/Roboto-Regular.ttf")).unwrap();
let gsub_lookups = font.gsub().unwrap().lookup_list().unwrap();
let lookup = gsub_lookups.lookups().get(1).unwrap();
let SubstitutionSubtables::Single(sub_tables) = lookup.subtables().unwrap() else {
panic!("Wrong type of lookup table!");
};
let singlesubst_table = sub_tables.get(0).unwrap();
let mut plan = Plan::default();
plan.glyph_map_gsub
.insert(GlyphId::from(777_u32), GlyphId::from(5_u32));
plan.glyph_map_gsub
.insert(GlyphId::from(779_u32), GlyphId::from(6_u32));
plan.glyph_map_gsub
.insert(GlyphId::from(885_u32), GlyphId::from(7_u32));
plan.glyph_map_gsub
.insert(GlyphId::from(1282_u32), GlyphId::from(8_u32));
plan.glyphset_gsub.insert(GlyphId::from(777_u32));
plan.glyphset_gsub.insert(GlyphId::from(779_u32));
plan.glyphset_gsub.insert(GlyphId::from(885_u32));
plan.glyphset_gsub.insert(GlyphId::from(1282_u32));
let mut s = Serializer::new(1024);
assert_eq!(s.start_serialize(), Ok(()));
let subset_state = SubsetState::default();
singlesubst_table
.subset(&plan, &mut s, (&subset_state, &font, &plan.gsub_lookups))
.unwrap();
assert!(!s.in_error());
s.end_serialize();
let subsetted_data = s.copy_bytes();
let expected_data: [u8; 14] = [
0x00, 0x01, 0x00, 0x06, 0x00, 0x02, 0x00, 0x01, 0x00, 0x02, 0x00, 0x05, 0x00, 0x06,
];
assert_eq!(subsetted_data, expected_data);
plan.glyph_map_gsub.clear();
plan.glyph_map_gsub
.insert(GlyphId::from(73_u32), GlyphId::from(1_u32));
plan.glyph_map_gsub
.insert(GlyphId::from(75_u32), GlyphId::from(2_u32));
plan.glyph_map_gsub
.insert(GlyphId::from(485_u32), GlyphId::from(3_u32));
plan.glyph_map_gsub
.insert(GlyphId::from(552_u32), GlyphId::from(4_u32));
plan.glyphset_gsub.clear();
plan.glyphset_gsub.insert(GlyphId::from(73_u32));
plan.glyphset_gsub.insert(GlyphId::from(75_u32));
plan.glyphset_gsub.insert(GlyphId::from(485_u32));
plan.glyphset_gsub.insert(GlyphId::from(552_u32));
let mut s = Serializer::new(1024);
assert_eq!(s.start_serialize(), Ok(()));
let subset_state = SubsetState::default();
singlesubst_table
.subset(&plan, &mut s, (&subset_state, &font, &plan.gsub_lookups))
.unwrap();
assert!(!s.in_error());
s.end_serialize();
let subsetted_data = s.copy_bytes();
let expected_data: [u8; 18] = [
0x00, 0x02, 0x00, 0x0a, 0x00, 0x02, 0x00, 0x04, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02,
0x00, 0x01, 0x00, 0x02,
];
assert_eq!(subsetted_data, expected_data);
}
}