| // https://docs.microsoft.com/en-us/typography/opentype/spec/post |
| |
| use crate::{LineMetrics, GlyphId}; |
| use crate::parser::{Stream, Fixed, LazyArray16}; |
| |
| |
| const TABLE_SIZE: usize = 32; |
| const ITALIC_ANGLE_OFFSET: usize = 4; |
| const UNDERLINE_POSITION_OFFSET: usize = 8; |
| const UNDERLINE_THICKNESS_OFFSET: usize = 10; |
| const IS_FIXED_PITCH_OFFSET: usize = 12; |
| |
| // https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6post.html |
| const MACINTOSH_NAMES: &[&str] = &[ |
| ".notdef", |
| ".null", |
| "nonmarkingreturn", |
| "space", |
| "exclam", |
| "quotedbl", |
| "numbersign", |
| "dollar", |
| "percent", |
| "ampersand", |
| "quotesingle", |
| "parenleft", |
| "parenright", |
| "asterisk", |
| "plus", |
| "comma", |
| "hyphen", |
| "period", |
| "slash", |
| "zero", |
| "one", |
| "two", |
| "three", |
| "four", |
| "five", |
| "six", |
| "seven", |
| "eight", |
| "nine", |
| "colon", |
| "semicolon", |
| "less", |
| "equal", |
| "greater", |
| "question", |
| "at", |
| "A", |
| "B", |
| "C", |
| "D", |
| "E", |
| "F", |
| "G", |
| "H", |
| "I", |
| "J", |
| "K", |
| "L", |
| "M", |
| "N", |
| "O", |
| "P", |
| "Q", |
| "R", |
| "S", |
| "T", |
| "U", |
| "V", |
| "W", |
| "X", |
| "Y", |
| "Z", |
| "bracketleft", |
| "backslash", |
| "bracketright", |
| "asciicircum", |
| "underscore", |
| "grave", |
| "a", |
| "b", |
| "c", |
| "d", |
| "e", |
| "f", |
| "g", |
| "h", |
| "i", |
| "j", |
| "k", |
| "l", |
| "m", |
| "n", |
| "o", |
| "p", |
| "q", |
| "r", |
| "s", |
| "t", |
| "u", |
| "v", |
| "w", |
| "x", |
| "y", |
| "z", |
| "braceleft", |
| "bar", |
| "braceright", |
| "asciitilde", |
| "Adieresis", |
| "Aring", |
| "Ccedilla", |
| "Eacute", |
| "Ntilde", |
| "Odieresis", |
| "Udieresis", |
| "aacute", |
| "agrave", |
| "acircumflex", |
| "adieresis", |
| "atilde", |
| "aring", |
| "ccedilla", |
| "eacute", |
| "egrave", |
| "ecircumflex", |
| "edieresis", |
| "iacute", |
| "igrave", |
| "icircumflex", |
| "idieresis", |
| "ntilde", |
| "oacute", |
| "ograve", |
| "ocircumflex", |
| "odieresis", |
| "otilde", |
| "uacute", |
| "ugrave", |
| "ucircumflex", |
| "udieresis", |
| "dagger", |
| "degree", |
| "cent", |
| "sterling", |
| "section", |
| "bullet", |
| "paragraph", |
| "germandbls", |
| "registered", |
| "copyright", |
| "trademark", |
| "acute", |
| "dieresis", |
| "notequal", |
| "AE", |
| "Oslash", |
| "infinity", |
| "plusminus", |
| "lessequal", |
| "greaterequal", |
| "yen", |
| "mu", |
| "partialdiff", |
| "summation", |
| "product", |
| "pi", |
| "integral", |
| "ordfeminine", |
| "ordmasculine", |
| "Omega", |
| "ae", |
| "oslash", |
| "questiondown", |
| "exclamdown", |
| "logicalnot", |
| "radical", |
| "florin", |
| "approxequal", |
| "Delta", |
| "guillemotleft", |
| "guillemotright", |
| "ellipsis", |
| "nonbreakingspace", |
| "Agrave", |
| "Atilde", |
| "Otilde", |
| "OE", |
| "oe", |
| "endash", |
| "emdash", |
| "quotedblleft", |
| "quotedblright", |
| "quoteleft", |
| "quoteright", |
| "divide", |
| "lozenge", |
| "ydieresis", |
| "Ydieresis", |
| "fraction", |
| "currency", |
| "guilsinglleft", |
| "guilsinglright", |
| "fi", |
| "fl", |
| "daggerdbl", |
| "periodcentered", |
| "quotesinglbase", |
| "quotedblbase", |
| "perthousand", |
| "Acircumflex", |
| "Ecircumflex", |
| "Aacute", |
| "Edieresis", |
| "Egrave", |
| "Iacute", |
| "Icircumflex", |
| "Idieresis", |
| "Igrave", |
| "Oacute", |
| "Ocircumflex", |
| "apple", |
| "Ograve", |
| "Uacute", |
| "Ucircumflex", |
| "Ugrave", |
| "dotlessi", |
| "circumflex", |
| "tilde", |
| "macron", |
| "breve", |
| "dotaccent", |
| "ring", |
| "cedilla", |
| "hungarumlaut", |
| "ogonek", |
| "caron", |
| "Lslash", |
| "lslash", |
| "Scaron", |
| "scaron", |
| "Zcaron", |
| "zcaron", |
| "brokenbar", |
| "Eth", |
| "eth", |
| "Yacute", |
| "yacute", |
| "Thorn", |
| "thorn", |
| "minus", |
| "multiply", |
| "onesuperior", |
| "twosuperior", |
| "threesuperior", |
| "onehalf", |
| "onequarter", |
| "threequarters", |
| "franc", |
| "Gbreve", |
| "gbreve", |
| "Idotaccent", |
| "Scedilla", |
| "scedilla", |
| "Cacute", |
| "cacute", |
| "Ccaron", |
| "ccaron", |
| "dcroat", |
| ]; |
| |
| |
| #[derive(Clone, Copy)] |
| pub struct Table<'a> { |
| italic_angle: f32, |
| underline: LineMetrics, |
| is_monospaced: bool, |
| name_indexes: LazyArray16<'a, u16>, |
| names: &'a [u8], |
| } |
| |
| impl<'a> Table<'a> { |
| pub fn parse(data: &'a [u8]) -> Option<Self> { |
| if data.len() < TABLE_SIZE { |
| return None; |
| } |
| |
| let version: u32 = Stream::new(data).read()?; |
| if !(version == 0x00010000 || version == 0x00020000 || |
| version == 0x00025000 || version == 0x00030000 || |
| version == 0x00040000) |
| { |
| return None; |
| } |
| |
| let italic_angle = Stream::read_at::<Fixed>(data, ITALIC_ANGLE_OFFSET)?.0; |
| |
| let underline = LineMetrics { |
| position: Stream::read_at::<i16>(data, UNDERLINE_POSITION_OFFSET)?, |
| thickness: Stream::read_at::<i16>(data, UNDERLINE_THICKNESS_OFFSET)?, |
| }; |
| |
| let is_monospaced = Stream::read_at::<u32>(data, IS_FIXED_PITCH_OFFSET)? != 0; |
| |
| let mut name_indexes = LazyArray16::default(); |
| let mut names: &[u8] = &[]; |
| |
| // Only version 2.0 of the table has data at the end. |
| if version == 0x00020000 { |
| let mut s = Stream::new_at(data, TABLE_SIZE)?; |
| let count: u16 = s.read()?; |
| name_indexes = s.read_array16::<u16>(count)?; |
| names = s.tail()?; |
| } |
| |
| Some(Table { |
| italic_angle, |
| underline, |
| is_monospaced, |
| name_indexes, |
| names, |
| }) |
| } |
| |
| #[inline] |
| pub fn italic_angle(&self) -> f32 { |
| self.italic_angle |
| } |
| |
| #[inline] |
| pub fn underline_metrics(&self) -> LineMetrics { |
| self.underline |
| } |
| |
| #[inline] |
| pub fn is_monospaced(&self) -> bool { |
| self.is_monospaced |
| } |
| |
| #[inline] |
| pub fn glyph_name(&self, glyph_id: GlyphId) -> Option<&'a str> { |
| let mut index = self.name_indexes.get(glyph_id.0)?; |
| |
| // 'If the name index is between 0 and 257, treat the name index |
| // as a glyph index in the Macintosh standard order.' |
| if usize::from(index) < MACINTOSH_NAMES.len() { |
| Some(MACINTOSH_NAMES[usize::from(index)]) |
| } else { |
| // 'If the name index is between 258 and 65535, then subtract 258 and use that |
| // to index into the list of Pascal strings at the end of the table.' |
| index -= MACINTOSH_NAMES.len() as u16; |
| |
| let mut s = Stream::new(self.names); |
| let mut i = 0; |
| while !s.at_end() && i < core::u16::MAX { |
| let len: u8 = s.read()?; |
| |
| if i == index { |
| if len == 0 { |
| // Empty name is an error. |
| break; |
| } else { |
| let name = s.read_bytes(usize::from(len))?; |
| return core::str::from_utf8(name).ok(); |
| } |
| } else { |
| s.advance(usize::from(len)); |
| } |
| |
| i += 1; |
| } |
| |
| None |
| } |
| } |
| } |
