libcosmic/examples/text/src/font/matches.rs
2022-10-10 13:13:04 -06:00

252 lines
8.9 KiB
Rust

use super::{Font, FontLineIndex, FontShapeGlyph, FontShapeWord, FontShapeLine, FontShapeSpan};
pub struct FontMatches<'a> {
pub fonts: Vec<&'a Font<'a>>,
}
impl<'a> FontMatches<'a> {
fn shape_word(&self, font_i: usize, line: &str, start_word: usize, end_word: usize, span_rtl: bool, blank: bool) -> FontShapeWord {
let word = &line[start_word..end_word];
let font_scale = self.fonts[font_i].rustybuzz.units_per_em() as f32;
let mut buffer = rustybuzz::UnicodeBuffer::new();
buffer.set_direction(if span_rtl {
rustybuzz::Direction::RightToLeft
} else {
rustybuzz::Direction::LeftToRight
});
buffer.push_str(word);
buffer.guess_segment_properties();
let rtl = match buffer.direction() {
rustybuzz::Direction::RightToLeft => true,
//TODO: other directions?
_ => false,
};
assert_eq!(rtl, span_rtl);
if font_i == 0 {
println!(
" Word {}{}: '{}'",
if rtl { "RTL" } else { "LTR" },
if blank { " BLANK" } else { "" },
word
);
}
let glyph_buffer = rustybuzz::shape(&self.fonts[font_i].rustybuzz, &[], buffer);
let glyph_infos = glyph_buffer.glyph_infos();
let glyph_positions = glyph_buffer.glyph_positions();
let mut missing = Vec::new();
let mut glyphs = Vec::with_capacity(glyph_infos.len());
for (info, pos) in glyph_infos.iter().zip(glyph_positions.iter()) {
let x_advance = pos.x_advance as f32 / font_scale;
let y_advance = pos.y_advance as f32 / font_scale;
let x_offset = pos.x_offset as f32 / font_scale;
let y_offset = pos.y_offset as f32 / font_scale;
//println!(" {:?} {:?}", info, pos);
if info.glyph_id == 0 {
missing.push(start_word + info.cluster as usize);
}
#[cfg(feature = "ab_glyph")]
let inner = ab_glyph::GlyphId(info.glyph_id as u16);
#[cfg(feature = "rusttype")]
let inner = font.rusttype.glyph(rusttype::GlyphId(info.glyph_id as u16));
#[cfg(feature = "swash")]
let inner = info.glyph_id as swash::GlyphId;
glyphs.push(FontShapeGlyph {
start: start_word + info.cluster as usize,
end: end_word, // Set later
x_advance,
y_advance,
x_offset,
y_offset,
#[cfg(feature = "ab_glyph")]
font: &self.fonts[font_i].ab_glyph,
#[cfg(feature = "swash")]
font: &self.fonts[font_i].swash,
inner,
});
}
// Adjust end of glyphs
if rtl {
for i in 1..glyphs.len() {
let next_start = glyphs[i - 1].start;
let next_end = glyphs[i - 1].end;
let prev = &mut glyphs[i];
if prev.start == next_start {
prev.end = next_end;
} else {
prev.end = next_start;
}
}
} else {
for i in (1..glyphs.len()).rev() {
let next_start = glyphs[i].start;
let next_end = glyphs[i].end;
let prev = &mut glyphs[i - 1];
if prev.start == next_start {
prev.end = next_end;
} else {
prev.end = next_start;
}
}
}
//TODO: improve performance!
if !missing.is_empty() && font_i + 1 < self.fonts.len() {
let mut missing_i = 0;
while missing_i < missing.len() {
let mut missing_glyph = missing[missing_i];
missing_i += 1;
let mut start_glyph = missing_glyph;
// Find beginning of glyphs to replace
let mut i = 0;
while i < glyphs.len() {
if glyphs[i].start == start_glyph {
break;
}
i += 1;
}
// Remove all matching glyphs and find end
let mut end_glyph = start_glyph;
while i < glyphs.len() {
if glyphs[i].start == missing_glyph {
let glyph = glyphs.remove(i);
if glyph.start < start_glyph {
start_glyph = glyph.start;
}
if glyph.end > end_glyph {
end_glyph = glyph.end;
}
} else if missing_i < missing.len() {
// Combine repeated missing items
if glyphs[i].start == missing[missing_i] {
missing_glyph = missing[missing_i];
missing_i += 1;
} else {
break;
}
} else {
break;
}
}
let mut fb_word = self.shape_word(font_i + 1, line, start_glyph, end_glyph, span_rtl, blank);
// Insert all matching glyphs
// println!("Locate fallback for {},{} '{}' from font {} to font {}", start_glyph, end_glyph, &line[start_glyph..end_glyph], font_i + 1, font_i);
let mut j = 0;
while j < fb_word.glyphs.len() {
if fb_word.glyphs[j].start >= start_glyph && fb_word.glyphs[j].end <= end_glyph {
// println!("Copy fallback for {},{} '{}' from font {} cluster {} to font {}", start_glyph, end_glyph, &line[start_glyph..end_glyph], font_i + 1, fb_word.glyphs[j].start, font_i);
glyphs.insert(i, fb_word.glyphs.remove(j));
i += 1;
} else {
j += 1;
}
}
}
}
/*
for glyph in glyphs.iter() {
println!("'{}': {}, {}, {}, {}", &line[glyph.start..glyph.end], glyph.x_advance, glyph.y_advance, glyph.x_offset, glyph.y_offset);
}
*/
FontShapeWord { blank, glyphs }
}
fn shape_span(&self, line: &str, start_span: usize, end_span: usize, line_rtl: bool, span_rtl: bool) -> FontShapeSpan {
let span = &line[start_span..end_span];
println!(" Span {}: '{}'", if span_rtl { "RTL" } else { "LTR" }, span);
let mut words = Vec::new();
let mut start_word = 0;
for (end_lb, _) in unicode_linebreak::linebreaks(span) {
let mut start_lb = end_lb;
for (i, c) in span[start_word..end_lb].char_indices() {
if start_word + i == end_lb {
break;
} else if c.is_whitespace() {
start_lb = start_word + i;
}
}
if start_word < start_lb {
words.push(self.shape_word(0, line, start_span + start_word, start_span + start_lb, span_rtl, false));
}
if start_lb < end_lb {
words.push(self.shape_word(0, line, start_span + start_lb, start_span + end_lb, span_rtl, true));
}
start_word = end_lb;
}
// Reverse glyphs in RTL lines
if line_rtl {
for word in words.iter_mut() {
word.glyphs.reverse();
}
}
// Reverse words in spans that do not match line direction
if line_rtl != span_rtl {
words.reverse();
}
FontShapeSpan {
rtl: span_rtl,
words,
}
}
pub fn shape_line(&self, line_i: FontLineIndex, line: &str) -> FontShapeLine {
let mut spans = Vec::new();
let bidi = unicode_bidi::BidiInfo::new(line, None);
let rtl = if bidi.paragraphs.is_empty() {
false
} else {
assert_eq!(bidi.paragraphs.len(), 1);
let para_info = &bidi.paragraphs[0];
let line_rtl = para_info.level.is_rtl();
println!("Line {}: '{}'", if line_rtl { "RTL" } else { "LTR" }, line);
let paragraph = unicode_bidi::Paragraph::new(&bidi, &para_info);
let mut start = 0;
let mut span_rtl = line_rtl;
for i in paragraph.para.range.clone() {
let next_rtl = paragraph.info.levels[i].is_rtl();
if span_rtl != next_rtl {
spans.push(self.shape_span(line, start, i, line_rtl, span_rtl));
span_rtl = next_rtl;
start = i;
}
}
spans.push(self.shape_span(line, start, line.len(), line_rtl, span_rtl));
line_rtl
};
FontShapeLine {
line_i,
rtl,
spans,
}
}
}