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Draw correct glyphs for non-embedded Identity TrueType CID fonts #566

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Draw correct glyphs for non-embedded Identity TrueType CID fonts #566

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292 changes: 292 additions & 0 deletions crates/pdf-font/src/cid_to_unicode.rs
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//! Best-effort CID-to-Unicode mappings for substituted CID fonts.

use std::{collections::HashMap, sync::Arc};

/// Best-effort CID-to-Unicode mapping used when a CID font has no `/ToUnicode` entry.
#[derive(Clone)]
pub enum CidToUnicode {
/// Inverted predefined Unicode CMap of a CJK character collection.
Collection(Arc<HashMap<u16, char>>),
/// CIDs are glyph indices in the standard Macintosh glyph order.
///
/// TrueType core fonts such as Arial, Times New Roman, and Courier New keep this order for
/// their first 258 glyphs. A non-embedded Identity CIDFontType2 font naming one of them
/// selects glyphs of that font by index, so its CIDs follow this order.
StandardGlyphOrder,
}

impl CidToUnicode {
/// Returns the Unicode value of `cid`, if known.
#[must_use]
pub fn get(&self, cid: u16) -> Option<char> {
match self {
Self::Collection(map) => map.get(&cid).copied(),
Self::StandardGlyphOrder => STANDARD_GLYPH_ORDER_UNICODE
.get(usize::from(cid))
.copied()
.flatten(),
}
}
}

/// Unicode value of each glyph in the standard Macintosh glyph order, by glyph index.
const STANDARD_GLYPH_ORDER_UNICODE: [Option<char>; 258] = [
None, // .notdef
None, // .null
None, // nonmarkingreturn
Some(' '), // space
Some('!'), // exclam
Some('"'), // quotedbl
Some('#'), // numbersign
Some('$'), // dollar
Some('%'), // percent
Some('&'), // ampersand
Some('\''), // quotesingle
Some('('), // parenleft
Some(')'), // parenright
Some('*'), // asterisk
Some('+'), // plus
Some(','), // comma
Some('-'), // hyphen
Some('.'), // period
Some('/'), // slash
Some('0'), // zero
Some('1'), // one
Some('2'), // two
Some('3'), // three
Some('4'), // four
Some('5'), // five
Some('6'), // six
Some('7'), // seven
Some('8'), // eight
Some('9'), // nine
Some(':'), // colon
Some(';'), // semicolon
Some('<'), // less
Some('='), // equal
Some('>'), // greater
Some('?'), // question
Some('@'), // at
Some('A'), // A
Some('B'), // B
Some('C'), // C
Some('D'), // D
Some('E'), // E
Some('F'), // F
Some('G'), // G
Some('H'), // H
Some('I'), // I
Some('J'), // J
Some('K'), // K
Some('L'), // L
Some('M'), // M
Some('N'), // N
Some('O'), // O
Some('P'), // P
Some('Q'), // Q
Some('R'), // R
Some('S'), // S
Some('T'), // T
Some('U'), // U
Some('V'), // V
Some('W'), // W
Some('X'), // X
Some('Y'), // Y
Some('Z'), // Z
Some('['), // bracketleft
Some('\\'), // backslash
Some(']'), // bracketright
Some('^'), // asciicircum
Some('_'), // underscore
Some('`'), // grave
Some('a'), // a
Some('b'), // b
Some('c'), // c
Some('d'), // d
Some('e'), // e
Some('f'), // f
Some('g'), // g
Some('h'), // h
Some('i'), // i
Some('j'), // j
Some('k'), // k
Some('l'), // l
Some('m'), // m
Some('n'), // n
Some('o'), // o
Some('p'), // p
Some('q'), // q
Some('r'), // r
Some('s'), // s
Some('t'), // t
Some('u'), // u
Some('v'), // v
Some('w'), // w
Some('x'), // x
Some('y'), // y
Some('z'), // z
Some('{'), // braceleft
Some('|'), // bar
Some('}'), // braceright
Some('~'), // asciitilde
Some('\u{00C4}'), // Adieresis
Some('\u{00C5}'), // Aring
Some('\u{00C7}'), // Ccedilla
Some('\u{00C9}'), // Eacute
Some('\u{00D1}'), // Ntilde
Some('\u{00D6}'), // Odieresis
Some('\u{00DC}'), // Udieresis
Some('\u{00E1}'), // aacute
Some('\u{00E0}'), // agrave
Some('\u{00E2}'), // acircumflex
Some('\u{00E4}'), // adieresis
Some('\u{00E3}'), // atilde
Some('\u{00E5}'), // aring
Some('\u{00E7}'), // ccedilla
Some('\u{00E9}'), // eacute
Some('\u{00E8}'), // egrave
Some('\u{00EA}'), // ecircumflex
Some('\u{00EB}'), // edieresis
Some('\u{00ED}'), // iacute
Some('\u{00EC}'), // igrave
Some('\u{00EE}'), // icircumflex
Some('\u{00EF}'), // idieresis
Some('\u{00F1}'), // ntilde
Some('\u{00F3}'), // oacute
Some('\u{00F2}'), // ograve
Some('\u{00F4}'), // ocircumflex
Some('\u{00F6}'), // odieresis
Some('\u{00F5}'), // otilde
Some('\u{00FA}'), // uacute
Some('\u{00F9}'), // ugrave
Some('\u{00FB}'), // ucircumflex
Some('\u{00FC}'), // udieresis
Some('\u{2020}'), // dagger
Some('\u{00B0}'), // degree
Some('\u{00A2}'), // cent
Some('\u{00A3}'), // sterling
Some('\u{00A7}'), // section
Some('\u{2022}'), // bullet
Some('\u{00B6}'), // paragraph
Some('\u{00DF}'), // germandbls
Some('\u{00AE}'), // registered
Some('\u{00A9}'), // copyright
Some('\u{2122}'), // trademark
Some('\u{00B4}'), // acute
Some('\u{00A8}'), // dieresis
Some('\u{2260}'), // notequal
Some('\u{00C6}'), // AE
Some('\u{00D8}'), // Oslash
Some('\u{221E}'), // infinity
Some('\u{00B1}'), // plusminus
Some('\u{2264}'), // lessequal
Some('\u{2265}'), // greaterequal
Some('\u{00A5}'), // yen
Some('\u{00B5}'), // mu
Some('\u{2202}'), // partialdiff
Some('\u{2211}'), // summation
Some('\u{220F}'), // product
Some('\u{03C0}'), // pi
Some('\u{222B}'), // integral
Some('\u{00AA}'), // ordfeminine
Some('\u{00BA}'), // ordmasculine
Some('\u{2126}'), // Omega
Some('\u{00E6}'), // ae
Some('\u{00F8}'), // oslash
Some('\u{00BF}'), // questiondown
Some('\u{00A1}'), // exclamdown
Some('\u{00AC}'), // logicalnot
Some('\u{221A}'), // radical
Some('\u{0192}'), // florin
Some('\u{2248}'), // approxequal
Some('\u{2206}'), // Delta
Some('\u{00AB}'), // guillemotleft
Some('\u{00BB}'), // guillemotright
Some('\u{2026}'), // ellipsis
Some('\u{00A0}'), // nonbreakingspace
Some('\u{00C0}'), // Agrave
Some('\u{00C3}'), // Atilde
Some('\u{00D5}'), // Otilde
Some('\u{0152}'), // OE
Some('\u{0153}'), // oe
Some('\u{2013}'), // endash
Some('\u{2014}'), // emdash
Some('\u{201C}'), // quotedblleft
Some('\u{201D}'), // quotedblright
Some('\u{2018}'), // quoteleft
Some('\u{2019}'), // quoteright
Some('\u{00F7}'), // divide
Some('\u{25CA}'), // lozenge
Some('\u{00FF}'), // ydieresis
Some('\u{0178}'), // Ydieresis
Some('\u{2044}'), // fraction
Some('\u{00A4}'), // currency
Some('\u{2039}'), // guilsinglleft
Some('\u{203A}'), // guilsinglright
Some('\u{FB01}'), // fi
Some('\u{FB02}'), // fl
Some('\u{2021}'), // daggerdbl
Some('\u{00B7}'), // periodcentered
Some('\u{201A}'), // quotesinglbase
Some('\u{201E}'), // quotedblbase
Some('\u{2030}'), // perthousand
Some('\u{00C2}'), // Acircumflex
Some('\u{00CA}'), // Ecircumflex
Some('\u{00C1}'), // Aacute
Some('\u{00CB}'), // Edieresis
Some('\u{00C8}'), // Egrave
Some('\u{00CD}'), // Iacute
Some('\u{00CE}'), // Icircumflex
Some('\u{00CF}'), // Idieresis
Some('\u{00CC}'), // Igrave
Some('\u{00D3}'), // Oacute
Some('\u{00D4}'), // Ocircumflex
Some('\u{F8FF}'), // apple
Some('\u{00D2}'), // Ograve
Some('\u{00DA}'), // Uacute
Some('\u{00DB}'), // Ucircumflex
Some('\u{00D9}'), // Ugrave
Some('\u{0131}'), // dotlessi
Some('\u{02C6}'), // circumflex
Some('\u{02DC}'), // tilde
Some('\u{00AF}'), // macron
Some('\u{02D8}'), // breve
Some('\u{02D9}'), // dotaccent
Some('\u{02DA}'), // ring
Some('\u{00B8}'), // cedilla
Some('\u{02DD}'), // hungarumlaut
Some('\u{02DB}'), // ogonek
Some('\u{02C7}'), // caron
Some('\u{0141}'), // Lslash
Some('\u{0142}'), // lslash
Some('\u{0160}'), // Scaron
Some('\u{0161}'), // scaron
Some('\u{017D}'), // Zcaron
Some('\u{017E}'), // zcaron
Some('\u{00A6}'), // brokenbar
Some('\u{00D0}'), // Eth
Some('\u{00F0}'), // eth
Some('\u{00DD}'), // Yacute
Some('\u{00FD}'), // yacute
Some('\u{00DE}'), // Thorn
Some('\u{00FE}'), // thorn
Some('\u{2212}'), // minus
Some('\u{00D7}'), // multiply
Some('\u{00B9}'), // onesuperior
Some('\u{00B2}'), // twosuperior
Some('\u{00B3}'), // threesuperior
Some('\u{00BD}'), // onehalf
Some('\u{00BC}'), // onequarter
Some('\u{00BE}'), // threequarters
Some('\u{20A3}'), // franc
Some('\u{011E}'), // Gbreve
Some('\u{011F}'), // gbreve
Some('\u{0130}'), // Idotaccent
Some('\u{015E}'), // Scedilla
Some('\u{015F}'), // scedilla
Some('\u{0106}'), // Cacute
Some('\u{0107}'), // cacute
Some('\u{010C}'), // Ccaron
Some('\u{010D}'), // ccaron
Some('\u{0111}'), // dcroat
];
1 change: 1 addition & 0 deletions crates/pdf-font/src/lib.rs
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Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
pub mod base_encoding;
pub mod cff;
pub mod cid_to_unicode;
pub mod encoding;
pub mod error;
pub mod fallback;
Expand Down
7 changes: 4 additions & 3 deletions crates/pdf-font/src/pdf_font_descriptor.rs
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Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
//! Best-effort font descriptor metadata and CID collection information.

use crate::{
cid_to_unicode::CidToUnicode,
flags::FontFlags,
font::{FontSlant, FontSource, FontWeight},
pdf::{CidSystemInfo, PdfFontDescriptor},
Expand All @@ -11,7 +12,7 @@ use pdf_graphics::rect::Rect;
use pdf_object_reader::{
DictionaryContext, FromPdfObject, ObjectAccess, ObjectContext, ReadResult,
};
use std::{collections::HashMap, sync::Arc};
use std::sync::Arc;

/// Metadata and the program selected for a specific font subtype.
struct Descriptor<P> {
Expand Down Expand Up @@ -119,7 +120,7 @@ impl FromPdfObject for CidSystemInfo {
}

/// Finds the existing collection-based Unicode fallback when the ordering is known.
pub(crate) fn cid_to_unicode_map(system_info: &CidSystemInfo) -> Option<Arc<HashMap<u16, char>>> {
pub(crate) fn cid_to_unicode_map(system_info: &CidSystemInfo) -> Option<CidToUnicode> {
let cmap_name: &[u8] = match system_info.ordering.as_ref() {
b"Japan1" => b"UniJIS-UCS2-HW-H",
b"GB1" => b"UniGB-UCS2-H",
Expand All @@ -130,5 +131,5 @@ pub(crate) fn cid_to_unicode_map(system_info: &CidSystemInfo) -> Option<Arc<Hash
PredefinedCMap::from_name(cmap_name)
.ok()
.flatten()
.map(|cmap| Arc::new(cmap.cid_to_unicode_map()))
.map(|cmap| CidToUnicode::Collection(Arc::new(cmap.cid_to_unicode_map())))
}
5 changes: 4 additions & 1 deletion crates/pdf-font/src/pdf_font_spec.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ use crate::pdf::{
SimpleFontSpec, Type0FontSpec, Type3FontSpec,
};
use crate::pdf_font_metrics::horizontal_metric;
use crate::standard14::Standard14Font;
use crate::standard14::{Standard14Font, from_base_font_name};
use pdf_cmap::WritingMode;

const NOTO_SANS_CJK_JP_REGULAR: &[u8] =
Expand Down Expand Up @@ -227,6 +227,9 @@ impl PdfFontSpec {
PdfFontSpec::Type1(font)
| PdfFontSpec::MultipleMasterType1(font)
| PdfFontSpec::TrueType(font) => font.standard14.unwrap_or_default(),
PdfFontSpec::Type0(font) => {
from_base_font_name(&font.base_font).unwrap_or(Standard14Font::Helvetica)
}
_ => Standard14Font::Helvetica,
}
}
Expand Down
7 changes: 7 additions & 0 deletions crates/pdf-font/src/standard14.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -196,6 +196,13 @@ pub(crate) fn from_flags(flags: FontFlags) -> Standard14Font {
}

impl Standard14Font {
/// Returns whether the TrueType core font behind this identity, such as Arial for Helvetica,
/// keeps the standard Macintosh glyph order. The symbol fonts do not.
#[must_use]
pub fn has_standard_glyph_order(self) -> bool {
!matches!(self, Self::Symbol | Self::ZapfDingbats)
}

/// Returns the advance width, in 1/1000 em, of a named glyph in this font's AFM metrics.
///
/// Courier is monospaced, so every glyph name is 600 units wide. Other fonts return `None`
Expand Down
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