1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
use ttf_parser::math::MathValue;
use ttf_parser::Tag;
use typst_library::foundations::{Style, StyleChain};
use typst_library::layout::{Abs, Em, FixedAlignment, Frame, Point, Size};
use typst_library::math::{EquationElem, MathSize};
use typst_library::text::{FontFeatures, TextElem};
use typst_utils::LazyHash;
use super::{LeftRightAlternator, MathContext, MathFragment, MathRun};
macro_rules! scaled {
($ctx:expr, $styles:expr, text: $text:ident, display: $display:ident $(,)?) => {
match $styles.get(typst_library::math::EquationElem::size) {
typst_library::math::MathSize::Display => scaled!($ctx, $styles, $display),
_ => scaled!($ctx, $styles, $text),
}
};
($ctx:expr, $styles:expr, $name:ident) => {
$crate::math::Scaled::scaled(
$ctx.constants.$name(),
$ctx,
$styles.resolve(typst_library::text::TextElem::size),
)
};
}
macro_rules! percent {
($ctx:expr, $name:ident) => {
$ctx.constants.$name() as f64 / 100.0
};
}
/// How much less high scaled delimiters can be than what they wrap.
pub const DELIM_SHORT_FALL: Em = Em::new(0.1);
/// Converts some unit to an absolute length with the current font & font size.
pub trait Scaled {
fn scaled(self, ctx: &MathContext, font_size: Abs) -> Abs;
}
impl Scaled for i16 {
fn scaled(self, ctx: &MathContext, font_size: Abs) -> Abs {
ctx.font.to_em(self).at(font_size)
}
}
impl Scaled for u16 {
fn scaled(self, ctx: &MathContext, font_size: Abs) -> Abs {
ctx.font.to_em(self).at(font_size)
}
}
impl Scaled for MathValue<'_> {
fn scaled(self, ctx: &MathContext, font_size: Abs) -> Abs {
self.value.scaled(ctx, font_size)
}
}
/// Styles something as cramped.
pub fn style_cramped() -> LazyHash<Style> {
EquationElem::cramped.set(true).wrap()
}
/// Sets flac OpenType feature.
pub fn style_flac() -> LazyHash<Style> {
TextElem::features
.set(FontFeatures(vec![(Tag::from_bytes(b"flac"), 1)]))
.wrap()
}
/// Sets dtls OpenType feature.
pub fn style_dtls() -> LazyHash<Style> {
TextElem::features
.set(FontFeatures(vec![(Tag::from_bytes(b"dtls"), 1)]))
.wrap()
}
/// The style for subscripts in the current style.
pub fn style_for_subscript(styles: StyleChain) -> [LazyHash<Style>; 2] {
[style_for_superscript(styles), EquationElem::cramped.set(true).wrap()]
}
/// The style for superscripts in the current style.
pub fn style_for_superscript(styles: StyleChain) -> LazyHash<Style> {
EquationElem::size
.set(match styles.get(EquationElem::size) {
MathSize::Display | MathSize::Text => MathSize::Script,
MathSize::Script | MathSize::ScriptScript => MathSize::ScriptScript,
})
.wrap()
}
/// The style for numerators in the current style.
pub fn style_for_numerator(styles: StyleChain) -> LazyHash<Style> {
EquationElem::size
.set(match styles.get(EquationElem::size) {
MathSize::Display => MathSize::Text,
MathSize::Text => MathSize::Script,
MathSize::Script | MathSize::ScriptScript => MathSize::ScriptScript,
})
.wrap()
}
/// The style for denominators in the current style.
pub fn style_for_denominator(styles: StyleChain) -> [LazyHash<Style>; 2] {
[style_for_numerator(styles), EquationElem::cramped.set(true).wrap()]
}
/// Styles to add font constants to the style chain.
pub fn style_for_script_scale(ctx: &MathContext) -> LazyHash<Style> {
EquationElem::script_scale
.set((
ctx.constants.script_percent_scale_down(),
ctx.constants.script_script_percent_scale_down(),
))
.wrap()
}
/// Stack rows on top of each other.
///
/// Add a `gap` between each row and uses the baseline of the `baseline`-th
/// row for the whole frame. `alternator` controls the left/right alternating
/// alignment behavior of `AlignPointElem` in the rows.
pub fn stack(
rows: Vec<MathRun>,
align: FixedAlignment,
gap: Abs,
baseline: usize,
alternator: LeftRightAlternator,
) -> Frame {
let AlignmentResult { points, width } = alignments(&rows);
let rows: Vec<_> = rows
.into_iter()
.map(|row| row.into_line_frame(&points, alternator))
.collect();
let mut frame = Frame::soft(Size::new(
width,
rows.iter().map(|row| row.height()).sum::<Abs>()
+ rows.len().saturating_sub(1) as f64 * gap,
));
let mut y = Abs::zero();
for (i, row) in rows.into_iter().enumerate() {
let x = if points.is_empty() {
align.position(width - row.width())
} else {
Abs::zero()
};
let pos = Point::new(x, y);
if i == baseline {
frame.set_baseline(y + row.baseline());
}
y += row.height() + gap;
frame.push_frame(pos, row);
}
frame
}
/// Determine the positions of the alignment points, according to the input rows combined.
pub fn alignments(rows: &[MathRun]) -> AlignmentResult {
let mut widths = Vec::<Abs>::new();
let mut pending_width = Abs::zero();
for row in rows {
let mut width = Abs::zero();
let mut alignment_index = 0;
for fragment in row.iter() {
if matches!(fragment, MathFragment::Align) {
if alignment_index < widths.len() {
widths[alignment_index].set_max(width);
} else {
widths.push(width.max(pending_width));
}
width = Abs::zero();
alignment_index += 1;
} else {
width += fragment.width();
}
}
if widths.is_empty() {
pending_width.set_max(width);
} else if alignment_index < widths.len() {
widths[alignment_index].set_max(width);
} else {
widths.push(width.max(pending_width));
}
}
let mut points = widths;
for i in 1..points.len() {
let prev = points[i - 1];
points[i] += prev;
}
AlignmentResult {
width: points.last().copied().unwrap_or(pending_width),
points,
}
}
pub struct AlignmentResult {
pub points: Vec<Abs>,
pub width: Abs,
}
|
