diff options
| -rw-r--r-- | crates/typst-layout/src/math/accent.rs | 59 | ||||
| -rw-r--r-- | crates/typst-layout/src/math/attach.rs | 6 | ||||
| -rw-r--r-- | crates/typst-layout/src/math/fragment.rs | 33 | ||||
| -rw-r--r-- | crates/typst-layout/src/math/stretch.rs | 2 | ||||
| -rw-r--r-- | crates/typst-library/src/math/accent.rs | 13 | ||||
| -rw-r--r-- | tests/ref/math-accent-bottom-high-base.png | bin | 0 -> 572 bytes | |||
| -rw-r--r-- | tests/ref/math-accent-bottom-sized.png | bin | 0 -> 382 bytes | |||
| -rw-r--r-- | tests/ref/math-accent-bottom-subscript.png | bin | 0 -> 417 bytes | |||
| -rw-r--r-- | tests/ref/math-accent-bottom-wide-base.png | bin | 0 -> 359 bytes | |||
| -rw-r--r-- | tests/ref/math-accent-bottom.png | bin | 0 -> 622 bytes | |||
| -rw-r--r-- | tests/ref/math-accent-nested.png | bin | 0 -> 537 bytes | |||
| -rw-r--r-- | tests/suite/math/accent.typ | 28 |
12 files changed, 108 insertions, 33 deletions
diff --git a/crates/typst-layout/src/math/accent.rs b/crates/typst-layout/src/math/accent.rs index 73d82101..53dfdf05 100644 --- a/crates/typst-layout/src/math/accent.rs +++ b/crates/typst-layout/src/math/accent.rs @@ -1,7 +1,7 @@ use typst_library::diag::SourceResult; use typst_library::foundations::{Packed, StyleChain}; use typst_library::layout::{Em, Frame, Point, Size}; -use typst_library::math::{Accent, AccentElem}; +use typst_library::math::AccentElem; use super::{style_cramped, FrameFragment, GlyphFragment, MathContext, MathFragment}; @@ -18,8 +18,11 @@ pub fn layout_accent( let cramped = style_cramped(); let mut base = ctx.layout_into_fragment(&elem.base, styles.chain(&cramped))?; - // Try to replace a glyph with its dotless variant. - if elem.dotless(styles) { + let accent = elem.accent; + let top_accent = !accent.is_bottom(); + + // Try to replace base glyph with its dotless variant. + if top_accent && elem.dotless(styles) { if let MathFragment::Glyph(glyph) = &mut base { glyph.make_dotless_form(ctx); } @@ -29,41 +32,54 @@ pub fn layout_accent( let base_class = base.class(); let base_attach = base.accent_attach(); - let width = elem.size(styles).relative_to(base.width()); - - let Accent(c) = elem.accent; - let mut glyph = GlyphFragment::new(ctx, styles, c, elem.span()); + let mut glyph = GlyphFragment::new(ctx, styles, accent.0, elem.span()); - // Try to replace accent glyph with flattened variant. - let flattened_base_height = scaled!(ctx, styles, flattened_accent_base_height); - if base.ascent() > flattened_base_height { - glyph.make_flattened_accent_form(ctx); + // Try to replace accent glyph with its flattened variant. + if top_accent { + let flattened_base_height = scaled!(ctx, styles, flattened_accent_base_height); + if base.ascent() > flattened_base_height { + glyph.make_flattened_accent_form(ctx); + } } // Forcing the accent to be at least as large as the base makes it too // wide in many case. + let width = elem.size(styles).relative_to(base.width()); let short_fall = ACCENT_SHORT_FALL.at(glyph.font_size); let variant = glyph.stretch_horizontal(ctx, width, short_fall); let accent = variant.frame; - let accent_attach = variant.accent_attach; + let accent_attach = variant.accent_attach.0; + + let (gap, accent_pos, base_pos) = if top_accent { + // Descent is negative because the accent's ink bottom is above the + // baseline. Therefore, the default gap is the accent's negated descent + // minus the accent base height. Only if the base is very small, we + // need a larger gap so that the accent doesn't move too low. + let accent_base_height = scaled!(ctx, styles, accent_base_height); + let gap = -accent.descent() - base.ascent().min(accent_base_height); + let accent_pos = Point::with_x(base_attach.0 - accent_attach); + let base_pos = Point::with_y(accent.height() + gap); + (gap, accent_pos, base_pos) + } else { + let gap = -accent.ascent(); + let accent_pos = Point::new(base_attach.1 - accent_attach, base.height() + gap); + let base_pos = Point::zero(); + (gap, accent_pos, base_pos) + }; - // Descent is negative because the accent's ink bottom is above the - // baseline. Therefore, the default gap is the accent's negated descent - // minus the accent base height. Only if the base is very small, we need - // a larger gap so that the accent doesn't move too low. - let accent_base_height = scaled!(ctx, styles, accent_base_height); - let gap = -accent.descent() - base.ascent().min(accent_base_height); let size = Size::new(base.width(), accent.height() + gap + base.height()); - let accent_pos = Point::with_x(base_attach - accent_attach); - let base_pos = Point::with_y(accent.height() + gap); let baseline = base_pos.y + base.ascent(); + let base_italics_correction = base.italics_correction(); let base_text_like = base.is_text_like(); - let base_ascent = match &base { MathFragment::Frame(frame) => frame.base_ascent, _ => base.ascent(), }; + let base_descent = match &base { + MathFragment::Frame(frame) => frame.base_descent, + _ => base.descent(), + }; let mut frame = Frame::soft(size); frame.set_baseline(baseline); @@ -73,6 +89,7 @@ pub fn layout_accent( FrameFragment::new(styles, frame) .with_class(base_class) .with_base_ascent(base_ascent) + .with_base_descent(base_descent) .with_italics_correction(base_italics_correction) .with_accent_attach(base_attach) .with_text_like(base_text_like), diff --git a/crates/typst-layout/src/math/attach.rs b/crates/typst-layout/src/math/attach.rs index e1d7d7c9..90aad941 100644 --- a/crates/typst-layout/src/math/attach.rs +++ b/crates/typst-layout/src/math/attach.rs @@ -434,9 +434,13 @@ fn compute_script_shifts( } if bl.is_some() || br.is_some() { + let descent = match &base { + MathFragment::Frame(frame) => frame.base_descent, + _ => base.descent(), + }; shift_down = shift_down .max(sub_shift_down) - .max(if is_text_like { Abs::zero() } else { base.descent() + sub_drop_min }) + .max(if is_text_like { Abs::zero() } else { descent + sub_drop_min }) .max(measure!(bl, ascent) - sub_top_max) .max(measure!(br, ascent) - sub_top_max); } diff --git a/crates/typst-layout/src/math/fragment.rs b/crates/typst-layout/src/math/fragment.rs index 59858a9c..85101c48 100644 --- a/crates/typst-layout/src/math/fragment.rs +++ b/crates/typst-layout/src/math/fragment.rs @@ -164,12 +164,12 @@ impl MathFragment { } } - pub fn accent_attach(&self) -> Abs { + pub fn accent_attach(&self) -> (Abs, Abs) { match self { Self::Glyph(glyph) => glyph.accent_attach, Self::Variant(variant) => variant.accent_attach, Self::Frame(fragment) => fragment.accent_attach, - _ => self.width() / 2.0, + _ => (self.width() / 2.0, self.width() / 2.0), } } @@ -241,7 +241,7 @@ pub struct GlyphFragment { pub ascent: Abs, pub descent: Abs, pub italics_correction: Abs, - pub accent_attach: Abs, + pub accent_attach: (Abs, Abs), pub font_size: Abs, pub class: MathClass, pub math_size: MathSize, @@ -296,7 +296,7 @@ impl GlyphFragment { descent: Abs::zero(), limits: Limits::for_char(c), italics_correction: Abs::zero(), - accent_attach: Abs::zero(), + accent_attach: (Abs::zero(), Abs::zero()), class, span, modifiers: FrameModifiers::get_in(styles), @@ -328,8 +328,14 @@ impl GlyphFragment { }); let mut width = advance.scaled(ctx, self.font_size); - let accent_attach = + + // The fallback for accents is half the width plus or minus the italics + // correction. This is similar to how top and bottom attachments are + // shifted. For bottom accents we do not use the accent attach of the + // base as it is meant for top acccents. + let top_accent_attach = accent_attach(ctx, id, self.font_size).unwrap_or((width + italics) / 2.0); + let bottom_accent_attach = (width - italics) / 2.0; let extended_shape = is_extended_shape(ctx, id); if !extended_shape { @@ -341,7 +347,7 @@ impl GlyphFragment { self.ascent = bbox.y_max.scaled(ctx, self.font_size); self.descent = -bbox.y_min.scaled(ctx, self.font_size); self.italics_correction = italics; - self.accent_attach = accent_attach; + self.accent_attach = (top_accent_attach, bottom_accent_attach); self.extended_shape = extended_shape; } @@ -459,7 +465,7 @@ impl Debug for GlyphFragment { pub struct VariantFragment { pub c: char, pub italics_correction: Abs, - pub accent_attach: Abs, + pub accent_attach: (Abs, Abs), pub frame: Frame, pub font_size: Abs, pub class: MathClass, @@ -501,8 +507,9 @@ pub struct FrameFragment { pub limits: Limits, pub spaced: bool, pub base_ascent: Abs, + pub base_descent: Abs, pub italics_correction: Abs, - pub accent_attach: Abs, + pub accent_attach: (Abs, Abs), pub text_like: bool, pub ignorant: bool, } @@ -510,6 +517,7 @@ pub struct FrameFragment { impl FrameFragment { pub fn new(styles: StyleChain, frame: Frame) -> Self { let base_ascent = frame.ascent(); + let base_descent = frame.descent(); let accent_attach = frame.width() / 2.0; Self { frame: frame.modified(&FrameModifiers::get_in(styles)), @@ -519,8 +527,9 @@ impl FrameFragment { limits: Limits::Never, spaced: false, base_ascent, + base_descent, italics_correction: Abs::zero(), - accent_attach, + accent_attach: (accent_attach, accent_attach), text_like: false, ignorant: false, } @@ -542,11 +551,15 @@ impl FrameFragment { Self { base_ascent, ..self } } + pub fn with_base_descent(self, base_descent: Abs) -> Self { + Self { base_descent, ..self } + } + pub fn with_italics_correction(self, italics_correction: Abs) -> Self { Self { italics_correction, ..self } } - pub fn with_accent_attach(self, accent_attach: Abs) -> Self { + pub fn with_accent_attach(self, accent_attach: (Abs, Abs)) -> Self { Self { accent_attach, ..self } } diff --git a/crates/typst-layout/src/math/stretch.rs b/crates/typst-layout/src/math/stretch.rs index f45035e2..6157d0c5 100644 --- a/crates/typst-layout/src/math/stretch.rs +++ b/crates/typst-layout/src/math/stretch.rs @@ -278,7 +278,7 @@ fn assemble( } let accent_attach = match axis { - Axis::X => frame.width() / 2.0, + Axis::X => (frame.width() / 2.0, frame.width() / 2.0), Axis::Y => base.accent_attach, }; diff --git a/crates/typst-library/src/math/accent.rs b/crates/typst-library/src/math/accent.rs index e62b6387..f2c9168c 100644 --- a/crates/typst-library/src/math/accent.rs +++ b/crates/typst-library/src/math/accent.rs @@ -80,6 +80,19 @@ impl Accent { pub fn new(c: char) -> Self { Self(Self::combine(c).unwrap_or(c)) } + + /// List of bottom accents. Currently just a list of ones included in the + /// Unicode math class document. + const BOTTOM: &[char] = &[ + '\u{0323}', '\u{032C}', '\u{032D}', '\u{032E}', '\u{032F}', '\u{0330}', + '\u{0331}', '\u{0332}', '\u{0333}', '\u{033A}', '\u{20E8}', '\u{20EC}', + '\u{20ED}', '\u{20EE}', '\u{20EF}', + ]; + + /// Whether this accent is a bottom accent or not. + pub fn is_bottom(&self) -> bool { + Self::BOTTOM.contains(&self.0) + } } /// This macro generates accent-related functions. diff --git a/tests/ref/math-accent-bottom-high-base.png b/tests/ref/math-accent-bottom-high-base.png Binary files differnew file mode 100644 index 00000000..23b14467 --- /dev/null +++ b/tests/ref/math-accent-bottom-high-base.png diff --git a/tests/ref/math-accent-bottom-sized.png b/tests/ref/math-accent-bottom-sized.png Binary files differnew file mode 100644 index 00000000..5455b2f5 --- /dev/null +++ b/tests/ref/math-accent-bottom-sized.png diff --git a/tests/ref/math-accent-bottom-subscript.png b/tests/ref/math-accent-bottom-subscript.png Binary files differnew file mode 100644 index 00000000..81854444 --- /dev/null +++ b/tests/ref/math-accent-bottom-subscript.png diff --git a/tests/ref/math-accent-bottom-wide-base.png b/tests/ref/math-accent-bottom-wide-base.png Binary files differnew file mode 100644 index 00000000..0475b485 --- /dev/null +++ b/tests/ref/math-accent-bottom-wide-base.png diff --git a/tests/ref/math-accent-bottom.png b/tests/ref/math-accent-bottom.png Binary files differnew file mode 100644 index 00000000..bd1b9214 --- /dev/null +++ b/tests/ref/math-accent-bottom.png diff --git a/tests/ref/math-accent-nested.png b/tests/ref/math-accent-nested.png Binary files differnew file mode 100644 index 00000000..4b3d58f3 --- /dev/null +++ b/tests/ref/math-accent-nested.png diff --git a/tests/suite/math/accent.typ b/tests/suite/math/accent.typ index ecc0588c..2239d897 100644 --- a/tests/suite/math/accent.typ +++ b/tests/suite/math/accent.typ @@ -58,3 +58,31 @@ $hat(a) hat(A)$ $tilde(w) tilde(W)$ $grave(i) grave(j)$ $grave(I) grave(J)$ + +--- math-accent-bottom --- +// Test bottom accents. +$accent(a, \u{20EE}), accent(T, \u{0323}), accent(xi, \u{0332}), + accent(f, \u{20ED}), accent(F, \u{20E8}), accent(y, \u{032E}), + accent(!, \u{032F}), accent(J, \u{0333}), accent(p, \u{0331})$ + +--- math-accent-bottom-wide-base --- +// Test wide base with bottom accents. +$accent(x + y, \u{20EF}), accent(sum, \u{032D})$ + +--- math-accent-bottom-subscript --- +// Test effect of bottom accent on subscript. +$q_x != accent(q, \u{032C})_x != accent(accent(q, \u{032C}), \u{032C})_x$ + +--- math-accent-bottom-high-base --- +// Test high base with bottom accents. +$ accent(integral, \u{20EC}), accent(integral, \u{20EC})_a^b, accent(integral_a^b, \u{20EC}) $ + +--- math-accent-bottom-sized --- +// Test bottom accent size. +$accent(sum, \u{0330}), accent(sum, \u{0330}, size: #50%), accent(H, \u{032D}, size: #200%)$ + +--- math-accent-nested --- +// Test nested top and bottom accents. +$hat(accent(L, \u{0330})), accent(circle(p), \u{0323}), + macron(accent(caron(accent(A, \u{20ED})), \u{0333})) \ + breve(accent(eta, \u{032E})) = accent(breve(eta), \u{032E})$ |
