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Merged
LaurenzV merged 3 commits into from
Sep 22, 2025
Merged

Change the API of parsing CFF tables to avoid a breaking change #200

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Change the API of parsing CFF tables to avoid a breaking change
LaurenzV Sep 9, 2025
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LaurenzV Sep 10, 2025
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LaurenzV Sep 10, 2025
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4 changes: 3 additions & 1 deletion src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1337,7 +1337,9 @@ impl<'a> Face<'a> {

bdat,
cbdt,
cff: raw_tables.cff.and_then(|data| cff::Table::parse(data, head.units_per_em)),
cff: raw_tables
.cff
.and_then(|data| cff::Table::parse_with_upem(data, head.units_per_em)),
cmap: raw_tables.cmap.and_then(cmap::Table::parse),
colr,
ebdt,
Expand Down
30 changes: 25 additions & 5 deletions src/tables/cff/cff1.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -374,8 +374,13 @@ fn parse_char_string(
local_subrs,
};

let transform = (metadata.units_per_em, metadata.matrix());
let transform = (transform != (1000, Matrix::default())).then_some(transform);
let (upem, transform) = (metadata.units_per_em, metadata.matrix());
let transform = if let Some(upem) = upem {
((upem, transform) != (1000, Matrix::default())).then_some((upem, transform))
} else {
None
};

let mut inner_builder = Builder {
builder,
bbox: RectF::new(),
Expand Down Expand Up @@ -802,7 +807,11 @@ fn parse_sid_metadata<'a>(
Some(FontKind::SID(metadata))
}

fn parse_cid_metadata(data: &[u8], top_dict: TopDict, number_of_glyphs: u16) -> Option<FontKind<'_>> {
fn parse_cid_metadata(
data: &[u8],
top_dict: TopDict,
number_of_glyphs: u16,
) -> Option<FontKind<'_>> {
let (charset_offset, fd_array_offset, fd_select_offset) = match (
top_dict.charset_offset,
top_dict.fd_array_offset,
Expand Down Expand Up @@ -852,12 +861,23 @@ pub struct Table<'a> {

// Copy of Face::units_per_em().
// Required to do glyph outlining, since coordinates must be scaled up by this before applying the `matrix`.
units_per_em: u16,
units_per_em: Option<u16>,
}

impl<'a> Table<'a> {
/// Parses a table from raw data.
pub fn parse(data: &'a [u8], units_per_em: u16) -> Option<Self> {
pub fn parse(data: &'a [u8]) -> Option<Self> {
Self::parse_inner(data, None)
}

/// The same as [`Table::parse`], with the difference that it allows you to
/// manually pass the units per em of the font, which is needed to properly
/// scale certain fonts with a non-identity matrix.
pub(crate) fn parse_with_upem(data: &'a [u8], units_per_em: u16) -> Option<Self> {
Self::parse_inner(data, Some(units_per_em))
}

fn parse_inner(data: &'a [u8], units_per_em: Option<u16>) -> Option<Self> {
let mut s = Stream::new(data);

// Parse Header.
Expand Down
26 changes: 13 additions & 13 deletions tests/tables/cff1.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -312,7 +312,7 @@ fn unsupported_version() {
UInt8(0), // absolute offset
]);

assert!(cff::Table::parse(&data, 1000).is_none());
assert!(cff::Table::parse(&data).is_none());
}

#[test]
Expand Down Expand Up @@ -360,7 +360,7 @@ fn non_default_header_size() {
UInt8(operator::ENDCHAR),
]);

let table = cff::Table::parse(&data, 1000).unwrap();
let table = cff::Table::parse(&data).unwrap();
let mut builder = Builder(String::new());
let rect = table.outline(GlyphId(0), &mut builder).unwrap();

Expand All @@ -377,7 +377,7 @@ macro_rules! test_cs_with_subrs {
#[test]
fn $name() {
let data = gen_cff($glob, $loc, $values);
let table = cff::Table::parse(&data, 1000).unwrap();
let table = cff::Table::parse(&data).unwrap();
let mut builder = Builder(String::new());
let rect = table.outline(GlyphId(0), &mut builder).unwrap();

Expand All @@ -398,7 +398,7 @@ macro_rules! test_cs_err {
#[test]
fn $name() {
let data = gen_cff(&[], &[], $values);
let table = cff::Table::parse(&data, 1000).unwrap();
let table = cff::Table::parse(&data).unwrap();
let mut builder = Builder(String::new());
let res = table.outline(GlyphId(0), &mut builder);
assert_eq!(res.unwrap_err(), $err);
Expand Down Expand Up @@ -575,7 +575,7 @@ test_cs!(vv_curve_to_with_x, &[
#[test]
fn only_endchar() {
let data = gen_cff(&[], &[], &[UInt8(operator::ENDCHAR)]);
let table = cff::Table::parse(&data, 1000).unwrap();
let table = cff::Table::parse(&data).unwrap();
let mut builder = Builder(String::new());
assert!(table.outline(GlyphId(0), &mut builder).is_err());
}
Expand Down Expand Up @@ -800,7 +800,7 @@ fn endchar_in_subr_with_extra_data_1() {
]
);

let table = cff::Table::parse(&data, 1000).unwrap();
let table = cff::Table::parse(&data).unwrap();
let mut builder = Builder(String::new());
let res = table.outline(GlyphId(0), &mut builder);
assert_eq!(res.unwrap_err(), CFFError::DataAfterEndChar);
Expand All @@ -827,7 +827,7 @@ fn endchar_in_subr_with_extra_data_2() {
]
);

let table = cff::Table::parse(&data, 1000).unwrap();
let table = cff::Table::parse(&data).unwrap();
let mut builder = Builder(String::new());
let res = table.outline(GlyphId(0), &mut builder);
assert_eq!(res.unwrap_err(), CFFError::DataAfterEndChar);
Expand All @@ -854,7 +854,7 @@ fn subr_without_return() {
]
);

let table = cff::Table::parse(&data, 1000).unwrap();
let table = cff::Table::parse(&data).unwrap();
let mut builder = Builder(String::new());
let res = table.outline(GlyphId(0), &mut builder);
assert_eq!(res.unwrap_err(), CFFError::DataAfterEndChar);
Expand All @@ -876,7 +876,7 @@ fn recursive_local_subr() {
]
);

let table = cff::Table::parse(&data, 1000).unwrap();
let table = cff::Table::parse(&data).unwrap();
let mut builder = Builder(String::new());
let res = table.outline(GlyphId(0), &mut builder);
assert_eq!(res.unwrap_err(), CFFError::NestingLimitReached);
Expand All @@ -898,7 +898,7 @@ fn recursive_global_subr() {
]
);

let table = cff::Table::parse(&data, 1000).unwrap();
let table = cff::Table::parse(&data).unwrap();
let mut builder = Builder(String::new());
let res = table.outline(GlyphId(0), &mut builder);
assert_eq!(res.unwrap_err(), CFFError::NestingLimitReached);
Expand All @@ -923,7 +923,7 @@ fn recursive_mixed_subr() {
]
);

let table = cff::Table::parse(&data, 1000).unwrap();
let table = cff::Table::parse(&data).unwrap();
let mut builder = Builder(String::new());
let res = table.outline(GlyphId(0), &mut builder);
assert_eq!(res.unwrap_err(), CFFError::NestingLimitReached);
Expand Down Expand Up @@ -952,7 +952,7 @@ fn zero_char_string_offset() {
UInt8(top_dict_operator::CHAR_STRINGS_OFFSET as u8),
]);

assert!(cff::Table::parse(&data, 1000).is_none());
assert!(cff::Table::parse(&data).is_none());
}

#[test]
Expand All @@ -978,7 +978,7 @@ fn invalid_char_string_offset() {
UInt8(top_dict_operator::CHAR_STRINGS_OFFSET as u8),
]);

assert!(cff::Table::parse(&data, 1000).is_none());
assert!(cff::Table::parse(&data).is_none());
}

// TODO: return from main
Expand Down
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