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use super::{RunSpecial, TextDisplay};
use crate::conv::{to_u32, to_usize};
use crate::fonts::{fonts, FontLibrary};
use crate::shaper::GlyphRun;
use crate::{Action, Align, EnvFlags, Range, Vec2};
use smallvec::SmallVec;
use unicode_bidi::Level;
#[derive(Clone, Debug)]
pub struct RunPart {
pub text_end: u32,
pub glyph_run: u32,
pub glyph_range: Range,
pub offset: Vec2,
}
#[derive(Clone, Debug)]
pub struct Line {
pub text_range: Range,
pub run_range: Range,
pub top: f32,
pub bottom: f32,
}
#[derive(Clone, Debug)]
struct PartInfo {
run: u32,
offset: f32,
len: f32,
len_no_space: f32,
glyph_range: Range,
end_space: bool,
}
impl TextDisplay {
pub fn prepare_lines(&mut self, bounds: Vec2, flags: EnvFlags, align: (Align, Align)) -> Vec2 {
assert!(
self.action <= Action::Wrap,
"kas-text::TextDisplay: runs not prepared"
);
self.action = Action::None;
let wrap = flags.contains(EnvFlags::WRAP);
let px_valign = flags.contains(EnvFlags::PX_VALIGN);
let fonts = fonts();
let capacity = 0;
let mut adder = LineAdder::new(capacity, bounds, align);
let width_bound = adder.width_bound;
let justify = align.0 == Align::Stretch;
let mut parts = Vec::with_capacity(16);
for line in self.line_runs.iter() {
let end_index = line.range.end();
debug_assert!(line.range.start < line.range.end);
assert!(end_index <= self.runs.len());
let level = match line.rtl {
false => Level::ltr(),
true => Level::rtl(),
};
let mut start = (line.range.start(), 0, 0);
let mut end = start;
parts.clear();
let mut caret = 0.0;
let mut index = start.0;
'a: while index < end_index {
let run = &self.runs[index];
let num_parts = run.num_parts();
let (allow_break, tab) = match run.special {
RunSpecial::None => (true, false),
RunSpecial::NoBreak => (false, false),
RunSpecial::HTab => (true, true),
};
let mut last_part = start.1;
let mut part = last_part + 1;
while part <= num_parts {
let (part_offset, part_len_no_space, mut part_len) =
run.part_lengths(last_part..part);
if tab {
let sf = fonts.get_face(run.face_id).scale_by_dpu(run.dpu);
let tab_size = sf.h_advance(sf.face().glyph_index(' ')) * 8.0;
let stops = (caret / tab_size).floor() + 1.0;
part_len = tab_size * stops - caret;
}
let line_len = caret + part_len_no_space;
if wrap && line_len > width_bound && end.2 > 0 {
let slice = &mut parts[0..end.2];
adder.add_line(fonts, level, &self.runs, slice, true, px_valign);
end.2 = 0;
start = end;
parts.clear();
caret = 0.0;
index = start.0;
continue 'a;
}
caret += part_len;
let glyph_range = run.to_glyph_range(last_part..part);
let checkpoint = part < num_parts || allow_break;
if !checkpoint
|| (justify && part_len_no_space > 0.0)
|| parts
.last()
.map(|part| to_usize(part.run) < index)
.unwrap_or(true)
{
parts.push(PartInfo {
run: to_u32(index),
offset: part_offset,
len: part_len,
len_no_space: part_len_no_space,
glyph_range,
end_space: false,
});
} else {
if let Some(part) = parts.last_mut() {
if run.level.is_ltr() {
part.glyph_range.end = glyph_range.end;
} else {
part.offset = part_offset;
part.glyph_range.start = glyph_range.start;
}
debug_assert!(part.glyph_range.start <= part.glyph_range.end);
if part_len_no_space > 0.0 {
part.len_no_space = part.len + part_len_no_space;
}
part.len += part_len;
}
}
if checkpoint {
end = (index, part, parts.len());
}
last_part = part;
part += 1;
}
index += 1;
start.1 = 0;
}
if parts.len() > 0 {
debug_assert_eq!(parts.len(), end.2);
adder.add_line(fonts, level, &self.runs, &mut parts, false, px_valign);
}
}
let required = adder.finish(bounds, align);
self.wrapped_runs = adder.runs;
self.lines = adder.lines;
self.num_glyphs = adder.num_glyphs;
self.width = bounds.0;
required
}
}
#[derive(Default)]
struct LineAdder {
runs: Vec<RunPart>,
lines: Vec<Line>,
line_gap: f32,
longest: f32,
vcaret: f32,
num_glyphs: u32,
halign: Align,
width_bound: f32,
}
impl LineAdder {
fn new(run_capacity: usize, bounds: Vec2, align: (Align, Align)) -> Self {
let runs = Vec::with_capacity(run_capacity);
LineAdder {
runs,
halign: align.0,
width_bound: bounds.0,
..Default::default()
}
}
fn add_line(
&mut self,
fonts: &FontLibrary,
line_level: Level,
runs: &[GlyphRun],
parts: &mut [PartInfo],
is_wrap: bool,
px_valign: bool,
) {
assert!(parts.len() > 0);
let line_start = self.runs.len();
let line_is_rtl = line_level.is_rtl();
let mut last_run = u32::MAX;
let (mut ascent, mut descent, mut line_gap) = (0f32, 0f32, 0f32);
let mut max_level = line_level;
for part in parts.iter() {
if last_run == part.run {
continue;
}
last_run = part.run;
let run = &runs[to_usize(last_run)];
let scale_font = fonts.get_face(run.face_id).scale_by_dpu(run.dpu);
ascent = ascent.max(scale_font.ascent());
descent = descent.min(scale_font.descent());
line_gap = line_gap.max(scale_font.line_gap());
debug_assert!(run.level >= line_level);
max_level = max_level.max(run.level);
}
self.vcaret += line_gap.max(self.line_gap) + ascent;
self.line_gap = line_gap;
let line_text_start = {
let part = &parts[0];
let run = &runs[to_usize(part.run)];
if run.level.is_ltr() {
if part.glyph_range.start() < run.glyphs.len() {
run.glyphs[part.glyph_range.start()].index
} else {
run.range.start
}
} else {
let end = part.glyph_range.end();
if 0 < end && end < run.glyphs.len() {
run.glyphs[end - 1].index
} else {
run.range.start
}
}
};
let mut line_text_end;
let mut line_len = 0.0;
{
let part = &mut parts[parts.len() - 1];
let run = &runs[to_usize(part.run)];
if is_wrap && part.len > part.len_no_space {
if part.glyph_range.start < part.glyph_range.end {
if run.level.is_ltr() {
part.glyph_range.end -= 1;
} else {
part.glyph_range.start += 1;
}
}
}
line_text_end = run.range.end;
if run.level.is_ltr() {
if part.glyph_range.end() < run.glyphs.len() {
line_text_end = run.glyphs[part.glyph_range.end()].index;
}
} else {
let start = part.glyph_range.start();
if 0 < start && start < run.glyphs.len() {
line_text_end = run.glyphs[start - 1].index
}
}
for part in parts.iter_mut().rev() {
part.end_space = true;
if part.len_no_space > 0.0 {
break;
}
}
for part in parts.iter() {
line_len += if part.end_space {
part.len_no_space
} else {
part.len
};
}
}
{
let mut level = max_level;
while level > Level::ltr() {
let mut start = None;
for i in 0..parts.len() {
let part_level = runs[to_usize(parts[i].run)].level;
if let Some(s) = start {
if part_level < level {
parts[s..i].reverse();
start = None;
}
} else {
if part_level >= level {
start = Some(i);
}
}
}
if let Some(s) = start {
parts[s..].reverse();
}
level.lower(1).unwrap();
}
}
let spare = self.width_bound - line_len;
let mut is_gap = SmallVec::<[bool; 16]>::new();
let mut per_gap = 0.0;
let mut caret = match self.halign {
Align::Default => match line_is_rtl {
false => 0.0,
true => spare,
},
Align::TL => 0.0,
Align::Center => 0.5 * spare,
Align::BR => spare,
Align::Stretch if !is_wrap => match line_is_rtl {
false => 0.0,
true => spare,
},
Align::Stretch => {
let len = parts.len();
is_gap.resize(len, false);
let mut num_gaps = 0;
for (i, part) in parts[..len - 1].iter().enumerate() {
let run = &runs[to_usize(part.run)];
let not_at_end = if run.level.is_ltr() {
part.glyph_range.end() < run.glyphs.len()
} else {
part.glyph_range.start > 0
};
if not_at_end || run.special != RunSpecial::NoBreak {
is_gap[i] = true;
num_gaps += 1;
}
}
let mut start = 0;
let mut level = runs[to_usize(parts[0].run)].level;
for i in 1..len {
let new_level = runs[to_usize(parts[i].run)].level;
if level != new_level {
if level > line_level {
is_gap[start..i].reverse();
}
start = i;
level = new_level;
}
}
if level > line_level {
is_gap[start..len - 1].reverse();
}
if line_level.is_rtl() {
is_gap.copy_within(1..len, 0);
}
per_gap = spare / (num_gaps as f32);
0.0
}
};
let mut end_caret = caret;
for (i, part) in parts.iter().enumerate() {
let run = &runs[to_usize(part.run)];
self.num_glyphs += to_u32(part.glyph_range.len());
let mut text_end = run.range.end;
let mut offset = 0.0;
if run.level.is_ltr() {
if part.glyph_range.end() < run.glyphs.len() {
text_end = run.glyphs[part.glyph_range.end()].index;
}
} else {
let start = part.glyph_range.start();
if 0 < start && start < run.glyphs.len() {
text_end = run.glyphs[start - 1].index
}
offset = part.len_no_space - part.len;
}
let xoffset = if part.end_space {
end_caret - part.offset + offset
} else {
caret - part.offset
};
self.runs.push(RunPart {
text_end,
glyph_run: part.run,
glyph_range: part.glyph_range.into(),
offset: Vec2(xoffset, self.vcaret),
});
if part.end_space {
caret += part.len_no_space;
end_caret += part.len;
} else {
caret += part.len;
end_caret = caret;
}
if is_gap.len() > 0 && is_gap[i] {
caret += per_gap;
end_caret += per_gap;
}
}
self.runs[line_start..].sort_by_key(|run| run.text_end);
let top = self.vcaret - ascent;
self.vcaret -= descent;
if px_valign {
self.vcaret = self.vcaret.round();
}
self.longest = self.longest.max(line_len);
self.lines.push(Line {
text_range: Range::from(line_text_start..line_text_end),
run_range: (line_start..self.runs.len()).into(),
top,
bottom: self.vcaret,
});
}
fn finish(&mut self, bounds: Vec2, align: (Align, Align)) -> Vec2 {
let height = self.vcaret;
let offset = match align.1 {
Align::Default | Align::TL | Align::Stretch => 0.0,
Align::Center => 0.5 * (bounds.1 - height),
Align::BR => bounds.1 - height,
};
if offset != 0.0 {
for run in &mut self.runs {
run.offset.1 += offset;
}
}
Vec2(self.longest, height)
}
}