review: resolve Symbol/ZapfDingbats codes through built-in encodings for widths

The width fallback decoded every code without a Differences entry as
cp1252, but Symbol and ZapfDingbats glyphs live at byte positions
unrelated to Latin text (Symbol 0x61 renders alpha, Zapf 0x21 renders
U+2701) — those codes missed their AFM entries and got the generic
default. Codes now resolve Differences -> built-in Symbol/Zapf encoding
-> cp1252 fallback, so advances match what the renderer draws.
Encoding tables generated from the Adobe standard encodings alongside
the width tables.
This commit is contained in:
Abimael Martell
2026-08-03 11:03:55 -07:00
parent 6689430534
commit e66cfec5aa
2 changed files with 124 additions and 0 deletions
+118
View File
@@ -34,6 +34,27 @@ pub(crate) fn is_base14_font(base_font: &str) -> bool {
base14_table(base_font).is_some()
}
/// Code → Unicode through the font's BUILT-IN encoding, for the base-14
/// fonts whose repertoire is not Latin (Symbol, ZapfDingbats). Their glyphs
/// live at byte positions that have nothing to do with cp1252 (Symbol 0x61
/// renders α, Zapf 0x21 renders ✁), so advance widths must be resolved
/// through this mapping — the renderer draws these glyphs regardless of how
/// the text decoder transliterates them. Returns `None` for the Latin text
/// fonts, which follow standard single-byte encodings.
pub(crate) fn builtin_encoding_char(base_font: &str, code: u8) -> Option<char> {
let table = base14_table(base_font)?;
let enc: &[(u8, char)] = if std::ptr::eq(table, SYMBOL) {
SYMBOL_ENCODING
} else if std::ptr::eq(table, ZAPFDINGBATS) {
ZAPFDINGBATS_ENCODING
} else {
return None;
};
enc.binary_search_by_key(&code, |&(b, _)| b)
.ok()
.map(|i| enc[i].1)
}
/// Map a BaseFont name (possibly subset-prefixed, e.g. "ABCDEF+Times-Bold",
/// or a common alias like "Arial" / "TimesNewRomanPSMT") to its width table.
fn base14_table(base_font: &str) -> Option<&'static [(char, u16)]> {
@@ -676,6 +697,80 @@ static ZAPFDINGBATS: &[(char, u16)] = &[
('\u{27BB}', 873), ('\u{27BC}', 927), ('\u{27BD}', 970), ('\u{27BE}', 918),
];
#[rustfmt::skip]
static SYMBOL_ENCODING: &[(u8, char)] = &[
(0x20, ' '), (0x21, '!'), (0x22, '\u{2200}'), (0x23, '#'), (0x24, '\u{2203}'), (0x25, '%'),
(0x26, '&'), (0x27, '\u{220B}'), (0x28, '('), (0x29, ')'), (0x2A, '\u{2217}'), (0x2B, '+'),
(0x2C, ','), (0x2D, '\u{2212}'), (0x2E, '.'), (0x2F, '/'), (0x30, '0'), (0x31, '1'),
(0x32, '2'), (0x33, '3'), (0x34, '4'), (0x35, '5'), (0x36, '6'), (0x37, '7'),
(0x38, '8'), (0x39, '9'), (0x3A, ':'), (0x3B, ';'), (0x3C, '<'), (0x3D, '='),
(0x3E, '>'), (0x3F, '?'), (0x40, '\u{2245}'), (0x41, '\u{0391}'), (0x42, '\u{0392}'), (0x43, '\u{03A7}'),
(0x44, '\u{2206}'), (0x45, '\u{0395}'), (0x46, '\u{03A6}'), (0x47, '\u{0393}'), (0x48, '\u{0397}'), (0x49, '\u{0399}'),
(0x4A, '\u{03D1}'), (0x4B, '\u{039A}'), (0x4C, '\u{039B}'), (0x4D, '\u{039C}'), (0x4E, '\u{039D}'), (0x4F, '\u{039F}'),
(0x50, '\u{03A0}'), (0x51, '\u{0398}'), (0x52, '\u{03A1}'), (0x53, '\u{03A3}'), (0x54, '\u{03A4}'), (0x55, '\u{03A5}'),
(0x56, '\u{03C2}'), (0x57, '\u{2126}'), (0x58, '\u{039E}'), (0x59, '\u{03A8}'), (0x5A, '\u{0396}'), (0x5B, '['),
(0x5C, '\u{2234}'), (0x5D, ']'), (0x5E, '\u{22A5}'), (0x5F, '_'), (0x60, '\u{F8E5}'), (0x61, '\u{03B1}'),
(0x62, '\u{03B2}'), (0x63, '\u{03C7}'), (0x64, '\u{03B4}'), (0x65, '\u{03B5}'), (0x66, '\u{03C6}'), (0x67, '\u{03B3}'),
(0x68, '\u{03B7}'), (0x69, '\u{03B9}'), (0x6A, '\u{03D5}'), (0x6B, '\u{03BA}'), (0x6C, '\u{03BB}'), (0x6D, '\u{00B5}'),
(0x6E, '\u{03BD}'), (0x6F, '\u{03BF}'), (0x70, '\u{03C0}'), (0x71, '\u{03B8}'), (0x72, '\u{03C1}'), (0x73, '\u{03C3}'),
(0x74, '\u{03C4}'), (0x75, '\u{03C5}'), (0x76, '\u{03D6}'), (0x77, '\u{03C9}'), (0x78, '\u{03BE}'), (0x79, '\u{03C8}'),
(0x7A, '\u{03B6}'), (0x7B, '{'), (0x7C, '|'), (0x7D, '}'), (0x7E, '\u{223C}'), (0xA0, '\u{20AC}'),
(0xA1, '\u{03D2}'), (0xA2, '\u{2032}'), (0xA3, '\u{2264}'), (0xA4, '\u{2044}'), (0xA5, '\u{221E}'), (0xA6, '\u{0192}'),
(0xA7, '\u{2663}'), (0xA8, '\u{2666}'), (0xA9, '\u{2665}'), (0xAA, '\u{2660}'), (0xAB, '\u{2194}'), (0xAC, '\u{2190}'),
(0xAD, '\u{2191}'), (0xAE, '\u{2192}'), (0xAF, '\u{2193}'), (0xB0, '\u{00B0}'), (0xB1, '\u{00B1}'), (0xB2, '\u{2033}'),
(0xB3, '\u{2265}'), (0xB4, '\u{00D7}'), (0xB5, '\u{221D}'), (0xB6, '\u{2202}'), (0xB7, '\u{2022}'), (0xB8, '\u{00F7}'),
(0xB9, '\u{2260}'), (0xBA, '\u{2261}'), (0xBB, '\u{2248}'), (0xBC, '\u{2026}'), (0xBD, '\u{F8E6}'), (0xBE, '\u{F8E7}'),
(0xBF, '\u{21B5}'), (0xC0, '\u{2135}'), (0xC1, '\u{2111}'), (0xC2, '\u{211C}'), (0xC3, '\u{2118}'), (0xC4, '\u{2297}'),
(0xC5, '\u{2295}'), (0xC6, '\u{2205}'), (0xC7, '\u{2229}'), (0xC8, '\u{222A}'), (0xC9, '\u{2283}'), (0xCA, '\u{2287}'),
(0xCB, '\u{2284}'), (0xCC, '\u{2282}'), (0xCD, '\u{2286}'), (0xCE, '\u{2208}'), (0xCF, '\u{2209}'), (0xD0, '\u{2220}'),
(0xD1, '\u{2207}'), (0xD2, '\u{F6DA}'), (0xD3, '\u{F6D9}'), (0xD4, '\u{F6DB}'), (0xD5, '\u{220F}'), (0xD6, '\u{221A}'),
(0xD7, '\u{22C5}'), (0xD8, '\u{00AC}'), (0xD9, '\u{2227}'), (0xDA, '\u{2228}'), (0xDB, '\u{21D4}'), (0xDC, '\u{21D0}'),
(0xDD, '\u{21D1}'), (0xDE, '\u{21D2}'), (0xDF, '\u{21D3}'), (0xE0, '\u{25CA}'), (0xE1, '\u{2329}'), (0xE2, '\u{F8E8}'),
(0xE3, '\u{F8E9}'), (0xE4, '\u{F8EA}'), (0xE5, '\u{2211}'), (0xE6, '\u{F8EB}'), (0xE7, '\u{F8EC}'), (0xE8, '\u{F8ED}'),
(0xE9, '\u{F8EE}'), (0xEA, '\u{F8EF}'), (0xEB, '\u{F8F0}'), (0xEC, '\u{F8F1}'), (0xED, '\u{F8F2}'), (0xEE, '\u{F8F3}'),
(0xEF, '\u{F8F4}'), (0xF1, '\u{232A}'), (0xF2, '\u{222B}'), (0xF3, '\u{2320}'), (0xF4, '\u{F8F5}'), (0xF5, '\u{2321}'),
(0xF6, '\u{F8F6}'), (0xF7, '\u{F8F7}'), (0xF8, '\u{F8F8}'), (0xF9, '\u{F8F9}'), (0xFA, '\u{F8FA}'), (0xFB, '\u{F8FB}'),
(0xFC, '\u{F8FC}'), (0xFD, '\u{F8FD}'), (0xFE, '\u{F8FE}'),
];
#[rustfmt::skip]
static ZAPFDINGBATS_ENCODING: &[(u8, char)] = &[
(0x20, ' '), (0x21, '\u{2701}'), (0x22, '\u{2702}'), (0x23, '\u{2703}'), (0x24, '\u{2704}'), (0x25, '\u{260E}'),
(0x26, '\u{2706}'), (0x27, '\u{2707}'), (0x28, '\u{2708}'), (0x29, '\u{2709}'), (0x2A, '\u{261B}'), (0x2B, '\u{261E}'),
(0x2C, '\u{270C}'), (0x2D, '\u{270D}'), (0x2E, '\u{270E}'), (0x2F, '\u{270F}'), (0x30, '\u{2710}'), (0x31, '\u{2711}'),
(0x32, '\u{2712}'), (0x33, '\u{2713}'), (0x34, '\u{2714}'), (0x35, '\u{2715}'), (0x36, '\u{2716}'), (0x37, '\u{2717}'),
(0x38, '\u{2718}'), (0x39, '\u{2719}'), (0x3A, '\u{271A}'), (0x3B, '\u{271B}'), (0x3C, '\u{271C}'), (0x3D, '\u{271D}'),
(0x3E, '\u{271E}'), (0x3F, '\u{271F}'), (0x40, '\u{2720}'), (0x41, '\u{2721}'), (0x42, '\u{2722}'), (0x43, '\u{2723}'),
(0x44, '\u{2724}'), (0x45, '\u{2725}'), (0x46, '\u{2726}'), (0x47, '\u{2727}'), (0x48, '\u{2605}'), (0x49, '\u{2729}'),
(0x4A, '\u{272A}'), (0x4B, '\u{272B}'), (0x4C, '\u{272C}'), (0x4D, '\u{272D}'), (0x4E, '\u{272E}'), (0x4F, '\u{272F}'),
(0x50, '\u{2730}'), (0x51, '\u{2731}'), (0x52, '\u{2732}'), (0x53, '\u{2733}'), (0x54, '\u{2734}'), (0x55, '\u{2735}'),
(0x56, '\u{2736}'), (0x57, '\u{2737}'), (0x58, '\u{2738}'), (0x59, '\u{2739}'), (0x5A, '\u{273A}'), (0x5B, '\u{273B}'),
(0x5C, '\u{273C}'), (0x5D, '\u{273D}'), (0x5E, '\u{273E}'), (0x5F, '\u{273F}'), (0x60, '\u{2740}'), (0x61, '\u{2741}'),
(0x62, '\u{2742}'), (0x63, '\u{2743}'), (0x64, '\u{2744}'), (0x65, '\u{2745}'), (0x66, '\u{2746}'), (0x67, '\u{2747}'),
(0x68, '\u{2748}'), (0x69, '\u{2749}'), (0x6A, '\u{274A}'), (0x6B, '\u{274B}'), (0x6C, '\u{25CF}'), (0x6D, '\u{274D}'),
(0x6E, '\u{25A0}'), (0x6F, '\u{274F}'), (0x70, '\u{2750}'), (0x71, '\u{2751}'), (0x72, '\u{2752}'), (0x73, '\u{25B2}'),
(0x74, '\u{25BC}'), (0x75, '\u{25C6}'), (0x76, '\u{2756}'), (0x77, '\u{25D7}'), (0x78, '\u{2758}'), (0x79, '\u{2759}'),
(0x7A, '\u{275A}'), (0x7B, '\u{275B}'), (0x7C, '\u{275C}'), (0x7D, '\u{275D}'), (0x7E, '\u{275E}'), (0x80, '\u{2768}'),
(0x81, '\u{2769}'), (0x82, '\u{276A}'), (0x83, '\u{276B}'), (0x84, '\u{276C}'), (0x85, '\u{276D}'), (0x86, '\u{276E}'),
(0x87, '\u{276F}'), (0x88, '\u{2770}'), (0x89, '\u{2771}'), (0x8A, '\u{2772}'), (0x8B, '\u{2773}'), (0x8C, '\u{2774}'),
(0x8D, '\u{2775}'), (0xA1, '\u{2761}'), (0xA2, '\u{2762}'), (0xA3, '\u{2763}'), (0xA4, '\u{2764}'), (0xA5, '\u{2765}'),
(0xA6, '\u{2766}'), (0xA7, '\u{2767}'), (0xA8, '\u{2663}'), (0xA9, '\u{2666}'), (0xAA, '\u{2665}'), (0xAB, '\u{2660}'),
(0xAC, '\u{2460}'), (0xAD, '\u{2461}'), (0xAE, '\u{2462}'), (0xAF, '\u{2463}'), (0xB0, '\u{2464}'), (0xB1, '\u{2465}'),
(0xB2, '\u{2466}'), (0xB3, '\u{2467}'), (0xB4, '\u{2468}'), (0xB5, '\u{2469}'), (0xB6, '\u{2776}'), (0xB7, '\u{2777}'),
(0xB8, '\u{2778}'), (0xB9, '\u{2779}'), (0xBA, '\u{277A}'), (0xBB, '\u{277B}'), (0xBC, '\u{277C}'), (0xBD, '\u{277D}'),
(0xBE, '\u{277E}'), (0xBF, '\u{277F}'), (0xC0, '\u{2780}'), (0xC1, '\u{2781}'), (0xC2, '\u{2782}'), (0xC3, '\u{2783}'),
(0xC4, '\u{2784}'), (0xC5, '\u{2785}'), (0xC6, '\u{2786}'), (0xC7, '\u{2787}'), (0xC8, '\u{2788}'), (0xC9, '\u{2789}'),
(0xCA, '\u{278A}'), (0xCB, '\u{278B}'), (0xCC, '\u{278C}'), (0xCD, '\u{278D}'), (0xCE, '\u{278E}'), (0xCF, '\u{278F}'),
(0xD0, '\u{2790}'), (0xD1, '\u{2791}'), (0xD2, '\u{2792}'), (0xD3, '\u{2793}'), (0xD4, '\u{2794}'), (0xD5, '\u{2192}'),
(0xD6, '\u{2194}'), (0xD7, '\u{2195}'), (0xD8, '\u{2798}'), (0xD9, '\u{2799}'), (0xDA, '\u{279A}'), (0xDB, '\u{279B}'),
(0xDC, '\u{279C}'), (0xDD, '\u{279D}'), (0xDE, '\u{279E}'), (0xDF, '\u{279F}'), (0xE0, '\u{27A0}'), (0xE1, '\u{27A1}'),
(0xE2, '\u{27A2}'), (0xE3, '\u{27A3}'), (0xE4, '\u{27A4}'), (0xE5, '\u{27A5}'), (0xE6, '\u{27A6}'), (0xE7, '\u{27A7}'),
(0xE8, '\u{27A8}'), (0xE9, '\u{27A9}'), (0xEA, '\u{27AA}'), (0xEB, '\u{27AB}'), (0xEC, '\u{27AC}'), (0xED, '\u{27AD}'),
(0xEE, '\u{27AE}'), (0xEF, '\u{27AF}'), (0xF1, '\u{27B1}'), (0xF2, '\u{27B2}'), (0xF3, '\u{27B3}'), (0xF4, '\u{27B4}'),
(0xF5, '\u{27B5}'), (0xF6, '\u{27B6}'), (0xF7, '\u{27B7}'), (0xF8, '\u{27B8}'), (0xF9, '\u{27B9}'), (0xFA, '\u{27BA}'),
(0xFB, '\u{27BB}'), (0xFC, '\u{27BC}'), (0xFD, '\u{27BD}'), (0xFE, '\u{27BE}'),
];
#[cfg(test)]
mod tests {
use super::*;
@@ -703,6 +798,29 @@ mod tests {
assert!(!is_base14_font("Garamond"));
}
#[test]
fn builtin_encoding_resolves_symbol_and_zapf_codes() {
// Symbol 0x61 renders alpha; Zapf 0x21 renders U+2701.
assert_eq!(builtin_encoding_char("Symbol", 0x61), Some('\u{03B1}'));
assert_eq!(builtin_encoding_char("Symbol", 0xA5), Some('\u{221E}'));
assert_eq!(
builtin_encoding_char("ZapfDingbats", 0x21),
Some('\u{2701}')
);
// Latin text fonts follow standard encodings — no builtin override.
assert_eq!(builtin_encoding_char("Times-Roman", 0x61), None);
// The resolved chars have real AFM widths.
let alpha_w = base14_char_width("Symbol", '\u{03B1}');
assert!(alpha_w.is_some() && alpha_w != Some(500));
}
#[test]
fn encoding_tables_are_sorted_for_binary_search() {
for table in [SYMBOL_ENCODING, ZAPFDINGBATS_ENCODING] {
assert!(table.windows(2).all(|w| w[0].0 < w[1].0));
}
}
#[test]
fn tables_are_sorted_for_binary_search() {
for table in [
+6
View File
@@ -240,9 +240,15 @@ fn base14_fallback_widths(doc: &Document, font_dict: &lopdf::Dictionary) -> Opti
let mut widths = HashMap::new();
for code in 0u16..=255 {
// Resolution order: Differences override, then the font's BUILT-IN
// encoding (Symbol/ZapfDingbats glyphs live at positions unrelated
// to cp1252 — the renderer draws α for Symbol 0x61 no matter how
// the text decoder transliterates it, so the advance must be α's),
// then the cp1252-style fallback used by the text decoder.
let ch = enc_map
.get(&(code as u8))
.copied()
.or_else(|| crate::extractor::base14::builtin_encoding_char(&base_font, code as u8))
.unwrap_or_else(|| decode_single_byte_fallback_char(code as u8, true));
if let Some(w) = crate::extractor::base14::base14_char_width(&base_font, ch) {
widths.insert(code, w);