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bflatasticandClaude Opus 5.5
65dd757d59
usvg knows vector-effect but drops it from the tree it returns, so every stroke was scaled by its transforms. The importer now records the shapes that ask for vector-effect="non-scaling-stroke" in its XML prepass (by id) and gives their strokes and dashes the width they have on screen; type does the same on its character strokes. Where the width can't be kept (art in patterns, markers or <use> copies, stretched or skewed type) the import warns. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
803 lines
34 KiB
Rust
803 lines
34 KiB
Rust
//! `<text>` import.
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//!
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//! usvg only converts text when it has fonts, and a font database is too expensive to load (and
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//! unavailable on wasm), so text is read from the XML. Before usvg runs, [`prepare`] replaces each
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//! `<text>` element with a placeholder `<g>` that carries the element's id, transform, conditional
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//! attributes, opacity, blending, clip, mask and filter. The group holds a rectangle over the text's
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//! bounds (id `{prefix}{i}`, filled with colour `i` so it is still found inside `<use>` instances,
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//! where usvg drops ids), followed by one rectangle per `url(#…)` paint, painted with it. usvg then
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//! keeps the text's z-order, parent groups, clips, masks and `<use>` instances, and resolves its
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//! gradients and patterns in the text's user space; the importer swaps each placeholder for the
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//! [`PendingText`] it stands for.
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//!
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//! Characters keep SVG's per-character `x`/`y`/`dx`/`dy`/`rotate` lists: a character with an
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//! absolute `x` that moves down by at least half a line starts a new line (the leading becomes the
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//! line spacing), other vertical moves become baseline shift, horizontal moves become kerning (an
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//! absolute `x` is measured against the laid-out text), and rotations become character rotation.
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//! `<textPath>` becomes type on a path; vertical `writing-mode` becomes type on a vertical path.
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use std::borrow::Cow;
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use std::cell::RefCell;
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use std::collections::HashMap;
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use std::fmt::Write as _;
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use std::ops::Range;
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use std::rc::Rc;
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use std::str::FromStr;
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use usvg::roxmltree;
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use vectorcraft_color::{Color, Paint};
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use vectorcraft_doc::{CharStyle, Dash, Justify, LineCap, LineJoin, TextKind, TextObject, TextRun};
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use vectorcraft_geom::kurbo::ParamCurveArclen;
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use vectorcraft_geom::{Affine, BezPath, PathData, Point, Rect};
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use vectorcraft_text::{FontDb, TextLayout};
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use super::css::{Styles, XNode};
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use super::{DEFAULT_FONT_SIZE, PT_PER_IN, href, vector_effect};
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use crate::xml_escape;
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const SVG_NS: &str = "http://www.w3.org/2000/svg";
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/// Most line breaks one absolutely positioned character adds before itself.
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const MAX_LINE_GAP: f64 = 10_000.0;
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/// A whitespace/comma separated list.
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fn list(v: &str) -> impl Iterator<Item = &str> {
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v.split(|c: char| c.is_whitespace() || c == ',').filter(|t| !t.is_empty())
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}
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/// Style name for a CSS weight (rounded to the nearest hundred) and slant.
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fn style_name(weight: u16, italic: bool) -> String {
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const NAMES: [&str; 9] = ["Thin", "ExtraLight", "Light", "Regular", "Medium", "SemiBold", "Bold", "ExtraBold", "Black"];
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let name = NAMES.get((weight.clamp(100, 900) as usize + 50) / 100 - 1).copied().unwrap_or("Regular");
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match (name, italic) {
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("Regular", true) => "Italic".into(),
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(n, true) => format!("{n} Italic"),
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(n, false) => n.into(),
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}
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}
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fn solid(c: svgtypes::Color) -> Paint {
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Paint::solid(Color::rgb8(c.red, c.green, c.blue))
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}
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fn parse_transform(s: Option<&str>) -> Affine {
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s.and_then(|s| svgtypes::Transform::from_str(s).ok()).map(|t| Affine::new([t.a, t.b, t.c, t.d, t.e, t.f])).unwrap_or(Affine::IDENTITY)
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}
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/// Character attributes an element gives its text.
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struct ElemStyle {
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style: CharStyle,
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/// `url(#…)` fill and stroke paints (resolved by usvg).
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fill: Option<String>,
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stroke: Option<String>,
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/// Extra space after each space character (`word-spacing`).
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word_spacing: f64,
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}
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/// One character of a text and the adjustments its position needs.
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struct Cell {
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ch: char,
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style: CharStyle,
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fill: Option<usize>,
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stroke: Option<usize>,
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/// Space added after the character, in points (becomes manual kerning).
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kern: f64,
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}
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impl Cell {
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fn final_style(&self) -> CharStyle {
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let mut st = self.style.clone();
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st.baseline_shift = finite(st.baseline_shift);
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if self.kern.is_finite() && self.kern.abs() > 1e-9 && st.size > 0.0 {
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st.kerning = Some(st.kerning.unwrap_or(0.0) + self.kern / st.size * 1000.0);
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}
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st
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}
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}
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/// The characters of a `<text>` after white-space processing.
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struct Chars<'a, 'i> {
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/// Each character and the element it comes from.
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chars: Vec<(char, XNode<'a, 'i>)>,
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/// Every element in tree order with the range of characters inside it.
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spans: Vec<(XNode<'a, 'i>, Range<usize>)>,
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/// The first `<textPath>`.
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path: Option<XNode<'a, 'i>>,
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}
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/// A line break before character `at`: `count` newlines, `leading` apart.
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struct Break {
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at: usize,
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count: usize,
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leading: f64,
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}
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/// A `<text>` element read from the XML, waiting for usvg to place it.
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#[derive(Clone)]
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pub(super) struct PendingText {
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/// The element's `id`.
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pub name: String,
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/// The text; `xf` maps text space into the element's user space.
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pub obj: TextObject,
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/// For each run, the index of its fill's and stroke's `url(#…)` paint, if any.
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pub servers: Vec<(Option<usize>, Option<usize>)>,
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/// Number of `url(#…)` paints (the placeholder paths after the main one, in order).
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pub paints: usize,
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/// `vector-effect="non-scaling-stroke"`: the character strokes keep their width on screen.
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pub non_scaling: bool,
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/// The placeholder rectangle in the element's user space.
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marker: Rect,
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}
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/// The texts [`prepare`] replaced, by placeholder index.
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pub(super) struct TextSlots {
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prefix: String,
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pub texts: Vec<PendingText>,
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}
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impl TextSlots {
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/// The text a placeholder's main path stands for: by its id, or inside `<use>` instances
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/// (where usvg drops ids) by its colour (the index) and its rectangle.
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pub fn find(&self, p: &usvg::Path) -> Option<usize> {
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if !p.id().is_empty() {
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return p.id().strip_prefix(&self.prefix)?.parse().ok();
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}
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let Some(usvg::Paint::Color(c)) = p.fill().map(|f| f.paint()) else { return None };
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if p.stroke().is_some() || p.data().segments().count() != 5 {
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return None;
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}
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let i = (c.red as usize) << 16 | (c.green as usize) << 8 | c.blue as usize;
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let m = self.texts.get(i)?.marker;
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let b = p.data().bounds();
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let near = |a: f32, b: f64| (a as f64 - b).abs() <= 1e-3 * b.abs().max(1.0);
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(near(b.left(), m.x0) && near(b.top(), m.y0) && near(b.right(), m.x1) && near(b.bottom(), m.y1)).then_some(i)
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}
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}
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/// Replace every `<text>` usvg would draw by a placeholder group (see the module docs).
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pub(super) fn prepare<'s>(svg: &'s str, xml: &roxmltree::Document, dpi: f64, warnings: &mut Vec<String>) -> (Cow<'s, str>, TextSlots) {
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let mut prefix = String::from("vectorcraft-text-");
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while xml.descendants().any(|n| n.attribute("id").is_some_and(|id| id.starts_with(&prefix))) {
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prefix.insert(0, '_');
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}
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let mut slots = TextSlots { prefix, texts: vec![] };
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let cx = Ctx::new(xml, dpi);
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let mut out = String::new();
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let mut copied = 0;
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for t in xml.descendants().filter(|n| n.is_element() && n.tag_name().name() == "text" && n.tag_name().namespace() == Some(SVG_NS)) {
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let label = t.attribute("id").map_or_else(|| "a text".to_string(), |id| format!("text '{id}'"));
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if t.ancestors().skip(1).any(|a| a.is_element() && a.tag_name().name() == "clipPath") {
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warnings.push(format!("{label} in a clip path ignored"));
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continue;
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}
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let r = t.range();
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// The element's qualified name (`text` or `svg:text`), so the placeholder lands in the same
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// namespace; skip anything whose source range isn't the element itself (entity expansions).
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let Some(qname) = svg
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.get(r.start..r.end)
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.and_then(|s| s.strip_prefix('<'))
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.map(|s| s.split(|c: char| c.is_whitespace() || c == '>' || c == '/').next().unwrap_or(""))
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else {
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continue;
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};
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let Some(q) = qname.strip_suffix("text").filter(|q| q.is_empty() || q.ends_with(':')) else { continue };
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if cx.css.own(t, "display").as_deref() == Some("none") || r.start < copied {
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continue;
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}
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let Some((text, paints)) = cx.build(xml, t, &label, warnings) else { continue };
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out.push_str(&svg[copied..r.start]);
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placeholder(&mut out, q, &cx.css, t, &slots.prefix, slots.texts.len(), text.marker, &paints);
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copied = r.end;
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slots.texts.push(text);
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}
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if slots.texts.is_empty() {
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return (Cow::Borrowed(svg), slots);
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}
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out.push_str(&svg[copied..]);
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(Cow::Owned(out), slots)
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}
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/// Write the placeholder group for text `t` (namespace prefix `q`), slot `index`.
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#[allow(clippy::too_many_arguments)]
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fn placeholder(out: &mut String, q: &str, css: &Styles, t: XNode, prefix: &str, index: usize, b: Rect, paints: &[String]) {
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let _ = write!(out, "<{q}g");
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for a in ["id", "transform", "systemLanguage", "requiredFeatures", "requiredExtensions"] {
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if let Some(v) = t.attribute(a) {
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let _ = write!(out, " {a}=\"{}\"", xml_escape(v));
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}
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}
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// The text's own non-inherited properties, overriding any rule that matches the `<g>`.
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let mut style = String::new();
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for (p, initial) in
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[("opacity", "1"), ("clip-path", "none"), ("mask", "none"), ("filter", "none"), ("mix-blend-mode", "normal"), ("isolation", "auto")]
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{
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let _ = write!(style, "{p}:{};", css.own(t, p).as_deref().unwrap_or(initial));
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}
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if let Some(v) = css.own(t, "visibility") {
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let _ = write!(style, "visibility:{v};");
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}
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let _ = write!(out, " style=\"{}display:inline\">", xml_escape(&style));
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let d = format!("M{} {}H{}V{}H{}Z", b.x0, b.y0, b.x1, b.y1, b.x0);
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const REST: &str = "stroke:none;opacity:1;display:inline;marker:none;clip-path:none;mask:none;filter:none";
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let _ = write!(out, "<{q}path id=\"{prefix}{index}\" style=\"fill:#{:06x};{REST}\" d=\"{d}\"/>", index & 0xff_ffff);
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for p in paints {
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let _ = write!(out, "<{q}path style=\"fill:{};{REST}\" d=\"{d}\"/>", xml_escape(p));
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}
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let _ = write!(out, "</{q}g>");
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}
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/// Computed text properties of the document's elements.
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struct Ctx {
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css: Styles,
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/// Pixels per inch absolute lengths convert at ([`super::RootUnits::dpi`]).
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dpi: f64,
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/// Viewport size in user units (the base of `x`/`y` percentages).
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viewport: (f64, f64),
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sizes: RefCell<HashMap<roxmltree::NodeId, f64>>,
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weights: RefCell<HashMap<roxmltree::NodeId, u16>>,
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elems: RefCell<HashMap<roxmltree::NodeId, Rc<ElemStyle>>>,
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}
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impl Ctx {
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fn new(xml: &roxmltree::Document, dpi: f64) -> Self {
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let mut cx = Self {
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css: Styles::new(xml),
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dpi,
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viewport: (100.0, 100.0),
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sizes: RefCell::default(),
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weights: RefCell::default(),
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elems: RefCell::default(),
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};
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let root = xml.root_element();
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let dim = |a: &str| root.attribute(a).and_then(|v| cx.length(v, DEFAULT_FONT_SIZE, 0.0)).filter(|v| *v > 0.0);
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cx.viewport = match root.attribute("viewBox").and_then(|v| svgtypes::ViewBox::from_str(v).ok()) {
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Some(vb) if vb.w > 0.0 && vb.h > 0.0 => (vb.w, vb.h),
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_ => (dim("width").unwrap_or(100.0), dim("height").unwrap_or(100.0)),
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};
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cx
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}
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/// A length in user units: absolute units convert at [`Self::dpi`], `em` and `ex` are relative
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/// to `em` (the font size) and percentages to `pct`.
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fn length(&self, v: &str, em: f64, pct: f64) -> Option<f64> {
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use svgtypes::LengthUnit as L;
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let l = svgtypes::Length::from_str(v.trim()).ok()?;
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let n = l.number;
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let v = match l.unit {
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L::None | L::Px => n,
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L::Pt => n * self.dpi / PT_PER_IN,
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L::Pc => n * self.dpi / 6.0,
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L::In => n * self.dpi,
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L::Cm => n * self.dpi / 2.54,
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L::Mm => n * self.dpi / 25.4,
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L::Em => n * em,
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L::Ex => n * em / 2.0,
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L::Percent => n / 100.0 * pct,
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};
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v.is_finite().then_some(v)
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}
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/// A `font-size` value given the parent's computed size (CSS keywords are relative to `medium`).
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fn parse_font_size(&self, v: &str, parent: f64) -> Option<f64> {
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let k = match v.trim() {
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"xx-small" => 3.0 / 5.0,
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"x-small" => 3.0 / 4.0,
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"small" => 8.0 / 9.0,
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"medium" => 1.0,
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"large" => 6.0 / 5.0,
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"x-large" => 3.0 / 2.0,
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"xx-large" => 2.0,
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"larger" => return Some(parent * 1.2),
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"smaller" => return Some(parent / 1.2),
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v => return self.length(v, parent, parent).filter(|s| *s > 0.0),
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};
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Some(DEFAULT_FONT_SIZE * k)
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}
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/// Computed `font-size` of an element.
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fn font_size(&self, n: XNode) -> f64 {
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if let Some(s) = self.sizes.borrow().get(&n.id()) {
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return *s;
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}
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let parent = n.parent_element().map_or(DEFAULT_FONT_SIZE, |p| self.font_size(p));
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let s = self.css.own(n, "font-size").and_then(|v| self.parse_font_size(&v, parent)).unwrap_or(parent);
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self.sizes.borrow_mut().insert(n.id(), s);
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s
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}
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/// Computed `font-weight` of an element (100–900).
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fn weight(&self, n: XNode) -> u16 {
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if let Some(w) = self.weights.borrow().get(&n.id()) {
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return *w;
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}
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let parent = n.parent_element().map_or(400, |p| self.weight(p));
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let w = match self.css.own(n, "font-weight").as_deref() {
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Some("normal") => 400,
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Some("bold") => 700,
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Some("bolder") => match parent {
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..=349 => 400,
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350..=549 => 700,
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_ => 900,
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},
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Some("lighter") => match parent {
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..=549 => 100,
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550..=749 => 400,
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_ => 700,
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},
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Some(v) => v.parse::<f64>().ok().filter(|w| (1.0..=1000.0).contains(w)).map_or(parent, |w| w.round() as u16),
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None => parent,
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};
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self.weights.borrow_mut().insert(n.id(), w);
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w
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}
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/// A fill or stroke: a ready paint, or a `url(#…)` paint for usvg to resolve.
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fn paint(&self, n: XNode, prop: &str) -> (Paint, Option<String>) {
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let initial = if prop == "fill" { Paint::solid(Color::BLACK) } else { Paint::None };
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let Some(v) = self.css.prop(n, prop) else { return (initial, None) };
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match svgtypes::Paint::from_str(&v) {
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Ok(svgtypes::Paint::None) => (Paint::None, None),
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Ok(svgtypes::Paint::Color(c)) => (solid(c), None),
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Ok(svgtypes::Paint::CurrentColor) => {
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(self.css.prop(n, "color").and_then(|c| svgtypes::Color::from_str(&c).ok()).map_or(Paint::solid(Color::BLACK), solid), None)
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}
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Ok(svgtypes::Paint::FuncIRI(..)) => (Paint::None, Some(v)),
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_ => (initial, None),
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}
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}
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/// Character attributes of an element inside `<text>` (cached).
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fn elem(&self, n: XNode) -> Rc<ElemStyle> {
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if let Some(e) = self.elems.borrow().get(&n.id()) {
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return e.clone();
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}
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let css = &self.css;
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let mut st = CharStyle::default();
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if let Some(f) = css.prop(n, "font-family") {
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let fam = f.split(',').next().unwrap_or("").trim().trim_matches(|c| c == '\'' || c == '"').to_string();
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if !fam.is_empty() {
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st.font_family = fam;
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}
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}
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let size = self.font_size(n);
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st.size = size;
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let italic = css.prop(n, "font-style").is_some_and(|s| s == "italic" || s == "oblique");
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st.font_style = style_name(self.weight(n), italic);
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let (fill, mut fill_url) = self.paint(n, "fill");
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st.fill = fill;
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let (stroke, mut stroke_url) = self.paint(n, "stroke");
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if !stroke.is_none() || stroke_url.is_some() {
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st.stroke = stroke;
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st.stroke_width = css.prop(n, "stroke-width").and_then(|w| self.length(&w, size, size)).unwrap_or(1.0);
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st.stroke_cap = match css.prop(n, "stroke-linecap").as_deref() {
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Some("round") => LineCap::Round,
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Some("square") => LineCap::Square,
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_ => LineCap::Butt,
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};
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st.stroke_join = match css.prop(n, "stroke-linejoin").as_deref() {
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Some("round") => LineJoin::Round,
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Some("bevel") => LineJoin::Bevel,
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_ => LineJoin::Miter,
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};
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st.stroke_miter_limit =
|
||
css.prop(n, "stroke-miterlimit").and_then(|m| m.trim().parse::<f64>().ok()).filter(|m| m.is_finite()).map_or(4.0, |m| m.max(1.0));
|
||
let pattern: Vec<f64> = css.prop(n, "stroke-dasharray").map_or(vec![], |d| list(&d).filter_map(|v| self.length(v, size, size)).collect());
|
||
let offset = css.prop(n, "stroke-dashoffset").and_then(|o| self.length(&o, size, size)).unwrap_or(0.0);
|
||
st.stroke_dash = Some(Dash { pattern, offset, align_corners: false }).filter(Dash::is_dashed);
|
||
}
|
||
if let Some(v) = css.prop(n, "letter-spacing").and_then(|v| self.length(&v, size, size))
|
||
&& size > 0.0
|
||
{
|
||
st.tracking = v / size * 1000.0;
|
||
}
|
||
if let Some(v) = css.prop(n, "kerning").and_then(|v| self.length(&v, size, size))
|
||
&& size > 0.0
|
||
{
|
||
st.kerning = Some(v / size * 1000.0);
|
||
}
|
||
if let Some(d) = css.prop(n, "text-decoration") {
|
||
st.underline = d.contains("underline");
|
||
st.strikethrough = d.contains("line-through");
|
||
}
|
||
// `baseline-shift` isn't inherited but nests: each element shifts its parent's baseline.
|
||
let own = match css.own(n, "baseline-shift").as_deref().map(str::trim) {
|
||
Some("sub") => -0.2 * size,
|
||
Some("super") => 0.4 * size,
|
||
Some(v) => self.length(v, size, size).unwrap_or(0.0),
|
||
None => 0.0,
|
||
};
|
||
let parent = if n.tag_name().name() == "text" { 0.0 } else { n.parent_element().map_or(0.0, |p| self.elem(p).style.baseline_shift) };
|
||
st.baseline_shift = parent + own;
|
||
if css.prop(n, "visibility").is_some_and(|v| v == "hidden" || v == "collapse") {
|
||
(st.fill, st.stroke, fill_url, stroke_url) = (Paint::None, Paint::None, None, None);
|
||
}
|
||
let word_spacing = css.prop(n, "word-spacing").and_then(|v| self.length(&v, size, size)).unwrap_or(0.0);
|
||
let e = Rc::new(ElemStyle { style: st, fill: fill_url, stroke: stroke_url, word_spacing });
|
||
self.elems.borrow_mut().insert(n.id(), e.clone());
|
||
e
|
||
}
|
||
|
||
/// Characters of `el` and its `<tspan>`, `<textPath>` and `<a>` children, with white space
|
||
/// handled like `xml:space` (newlines and tabs become spaces; runs of spaces collapse unless
|
||
/// preserved).
|
||
fn collect<'b, 'i>(&self, el: XNode<'b, 'i>, preserve: bool, out: &mut Chars<'b, 'i>) {
|
||
let start = out.chars.len();
|
||
let slot = out.spans.len();
|
||
out.spans.push((el, start..start));
|
||
for c in el.children() {
|
||
if c.is_text() {
|
||
for ch in c.text().unwrap_or("").chars() {
|
||
let ch = if matches!(ch, '\n' | '\r' | '\t') { ' ' } else { ch };
|
||
if !preserve && ch == ' ' && out.chars.last().is_none_or(|(p, _)| *p == ' ') {
|
||
continue;
|
||
}
|
||
out.chars.push((ch, el));
|
||
}
|
||
} else if c.is_element()
|
||
&& c.tag_name().namespace() == Some(SVG_NS)
|
||
&& matches!(c.tag_name().name(), "tspan" | "textPath" | "a")
|
||
&& self.css.own(c, "display").as_deref() != Some("none")
|
||
{
|
||
if c.tag_name().name() == "textPath" {
|
||
out.path.get_or_insert(c);
|
||
}
|
||
self.collect(c, preserve, out);
|
||
}
|
||
}
|
||
out.spans[slot].1 = start..out.chars.len();
|
||
}
|
||
|
||
/// The path a `<textPath>` follows, in the text's user space.
|
||
fn text_path(&self, xml: &roxmltree::Document, tp: XNode) -> Option<BezPath> {
|
||
let mut bp = match tp.attribute("path") {
|
||
Some(d) => BezPath::from_svg(d).ok()?,
|
||
None => {
|
||
let id = href(tp)?.trim().strip_prefix('#')?;
|
||
let el = xml.descendants().find(|n| n.is_element() && n.attribute("id") == Some(id))?;
|
||
if el.tag_name().name() != "path" {
|
||
return None;
|
||
}
|
||
let mut bp = BezPath::from_svg(el.attribute("d")?).ok()?;
|
||
bp.apply_affine(parse_transform(el.attribute("transform")));
|
||
bp
|
||
}
|
||
};
|
||
if tp.attribute("side") == Some("right") {
|
||
bp = bp.reverse_subpaths();
|
||
}
|
||
let usable = bp.segments().next().is_some();
|
||
usable.then_some(bp)
|
||
}
|
||
|
||
/// Read one `<text>`: the pending text and its `url(#…)` paints.
|
||
fn build(&self, xml: &roxmltree::Document, t: XNode, label: &str, warnings: &mut Vec<String>) -> Option<(PendingText, Vec<String>)> {
|
||
let preserve = t.ancestors().filter(|a| a.is_element()).find_map(|a| a.attribute((roxmltree::NS_XML_URI, "space"))) == Some("preserve");
|
||
let mut cs = Chars { chars: vec![], spans: vec![], path: None };
|
||
self.collect(t, preserve, &mut cs);
|
||
if !preserve {
|
||
while cs.chars.last().is_some_and(|c| c.0 == ' ') {
|
||
cs.chars.pop();
|
||
}
|
||
}
|
||
let n = cs.chars.len();
|
||
if n == 0 {
|
||
return None;
|
||
}
|
||
|
||
// Positioning lists, applied in tree order so descendants override their ancestors.
|
||
let (vw, vh) = self.viewport;
|
||
let (mut x, mut y, mut dx, mut dy, mut rot) = (vec![None; n], vec![None; n], vec![0.0; n], vec![0.0; n], vec![None; n]);
|
||
for (el, r) in &cs.spans {
|
||
let r = r.start.min(n)..r.end.min(n);
|
||
let em = self.font_size(*el);
|
||
let apply = |name: &str, pct: f64, put: &mut dyn FnMut(usize, f64)| {
|
||
if let Some(v) = el.attribute(name) {
|
||
for (i, l) in r.clone().zip(list(v).filter_map(|t| self.length(t, em, pct))) {
|
||
put(i, l);
|
||
}
|
||
}
|
||
};
|
||
apply("x", vw, &mut |i, v| x[i] = Some(v));
|
||
apply("y", vh, &mut |i, v| y[i] = Some(v));
|
||
apply("dx", vw, &mut |i, v| dx[i] = v);
|
||
apply("dy", vh, &mut |i, v| dy[i] = v);
|
||
// A shorter rotate list repeats its last value.
|
||
let angles: Vec<f64> =
|
||
el.attribute("rotate").map(|v| list(v).filter_map(|t| t.parse().ok()).filter(|a: &f64| a.is_finite()).collect()).unwrap_or_default();
|
||
if let Some(&last) = angles.last() {
|
||
for (k, i) in r.enumerate() {
|
||
rot[i] = Some(*angles.get(k).unwrap_or(&last));
|
||
}
|
||
}
|
||
}
|
||
|
||
let mut paints: Vec<String> = vec![];
|
||
let mut paint_index = |url: &Option<String>| {
|
||
url.as_ref().map(|u| {
|
||
paints.iter().position(|p| p == u).unwrap_or_else(|| {
|
||
paints.push(u.clone());
|
||
paints.len() - 1
|
||
})
|
||
})
|
||
};
|
||
let mut cells: Vec<Cell> = cs
|
||
.chars
|
||
.iter()
|
||
.zip(&rot)
|
||
.map(|((ch, el), r)| {
|
||
let e = self.elem(*el);
|
||
let mut style = e.style.clone();
|
||
if let Some(r) = r {
|
||
style.rotation = -r;
|
||
}
|
||
Cell {
|
||
ch: *ch,
|
||
style,
|
||
fill: paint_index(&e.fill),
|
||
stroke: paint_index(&e.stroke),
|
||
kern: if *ch == ' ' { e.word_spacing } else { 0.0 },
|
||
}
|
||
})
|
||
.collect();
|
||
|
||
let anchor = match self.css.prop(cs.chars[0].1, "text-anchor").as_deref() {
|
||
Some("middle") => 0.5,
|
||
Some("end") => 1.0,
|
||
_ => 0.0,
|
||
};
|
||
let path = cs.path.and_then(|tp| match self.text_path(xml, tp) {
|
||
Some(p) => Some((tp, p)),
|
||
None => {
|
||
warnings.push(format!("{label}: textPath has no usable path; imported as point type"));
|
||
None
|
||
}
|
||
});
|
||
let vertical = self.css.prop(t, "writing-mode").is_some_and(|m| m.starts_with("tb") || m.starts_with("vertical"));
|
||
let mut obj = TextObject::point(Point::ZERO, "", CharStyle::default());
|
||
let mut breaks: Vec<Break> = vec![];
|
||
if let Some((tp, bp)) = path {
|
||
// Along the path: dx is extra advance, dy shifts off the path.
|
||
let mut off = 0.0;
|
||
for i in 0..n {
|
||
off -= dy[i];
|
||
cells[i].style.baseline_shift += off;
|
||
if i > 0 {
|
||
cells[i - 1].kern += dx[i];
|
||
}
|
||
}
|
||
let len: f64 = bp.segments().map(|s| s.arclen(1e-4)).sum();
|
||
let em = self.font_size(tp);
|
||
let offset = tp.attribute("startOffset").and_then(|v| self.length(v, em, len)).unwrap_or(0.0) + dx[0];
|
||
let width = if anchor > 0.0 { advance(&point_text(&cells)) } else { 0.0 };
|
||
let start = Some((offset - anchor * width) / len).filter(|s| s.is_finite()).map_or(0.0, |s| s.clamp(0.0, 1.0));
|
||
obj.kind = TextKind::OnPath { path: PathData::from_bezpath(&bp), start };
|
||
obj.xf = Affine::IDENTITY;
|
||
} else if vertical {
|
||
// Type on a vertical path: dy is extra advance, dx shifts across the column.
|
||
let mut off = 0.0;
|
||
for i in 0..n {
|
||
off += dx[i];
|
||
cells[i].style.baseline_shift += off;
|
||
if i > 0 {
|
||
cells[i - 1].kern += dy[i];
|
||
}
|
||
}
|
||
let lay = measure(&point_text(&cells));
|
||
let width: f64 = lay.glyphs.iter().map(|g| g.advance).sum();
|
||
// Glyphs turn 90° clockwise; centre the em box on the column (SVG's central baseline).
|
||
let centre = lay.lines.first().map_or(0.0, |l| (l.ascent - l.descent) / 2.0);
|
||
let (x0, y0) = (finite(x[0].unwrap_or(0.0) - centre), finite(y[0].unwrap_or(0.0) + dy[0] - anchor * width));
|
||
let mut bp = BezPath::new();
|
||
bp.move_to((x0, y0));
|
||
bp.line_to((x0, y0 + width + 1.0));
|
||
obj.kind = TextKind::OnPath { path: PathData::from_bezpath(&bp), start: 0.0 };
|
||
obj.xf = Affine::IDENTITY;
|
||
} else {
|
||
let origin = Point::new(x[0].unwrap_or(0.0) + dx[0], y[0].unwrap_or(0.0) + dy[0]);
|
||
let (justify, left) = lines(&mut cells, &x, &y, &dx, &dy, anchor, origin.x, &mut breaks);
|
||
obj.para.justify = justify;
|
||
obj.xf = Affine::translate((finite(left), finite(origin.y)));
|
||
}
|
||
let (runs, servers) = assemble(&cells, &breaks).0;
|
||
obj.runs = runs;
|
||
// The placeholder covers the text (laid out when a paint server needs its bounding box).
|
||
let b = if paints.is_empty() { obj.bounds() } else { Some(obj.xf.transform_rect_bbox(measure(&obj).bounds)) }.unwrap_or_default();
|
||
let marker = Rect::new(b.x0, b.y0, b.x1.max(b.x0 + 1.0), b.y1.max(b.y0 + 1.0));
|
||
let name = t.attribute("id").unwrap_or("").to_string();
|
||
let non_scaling = vector_effect::is_non_scaling(&self.css, t);
|
||
Some((PendingText { name, obj, servers, paints: paints.len(), non_scaling, marker }, paints))
|
||
}
|
||
}
|
||
|
||
/// `v`, or 0 when far-off positions added up past f64's range.
|
||
fn finite(v: f64) -> f64 {
|
||
if v.is_finite() { v } else { 0.0 }
|
||
}
|
||
|
||
/// Point type: line breaks, baseline shifts and kerning from the positioning lists. Returns the
|
||
/// justification and the x of the first line's left (or anchor) edge.
|
||
#[allow(clippy::too_many_arguments)]
|
||
fn lines(
|
||
cells: &mut [Cell],
|
||
x: &[Option<f64>],
|
||
y: &[Option<f64>],
|
||
dx: &[f64],
|
||
dy: &[f64],
|
||
anchor: f64,
|
||
x0: f64,
|
||
breaks: &mut Vec<Break>,
|
||
) -> (Justify, f64) {
|
||
let n = cells.len();
|
||
let y0 = y[0].unwrap_or(0.0) + dy[0];
|
||
let (mut base, mut cur) = (y0, y0);
|
||
// Line starts (first character, anchor x) and absolutely placed characters (index, x).
|
||
let mut lines = vec![(0, x0)];
|
||
let mut targets: Vec<(usize, f64)> = vec![];
|
||
for i in 1..n {
|
||
let ny = y[i].unwrap_or(cur) + dy[i];
|
||
let lead = cells[i].style.effective_leading();
|
||
let gap = ny - base;
|
||
if let Some(ax) = x[i].filter(|_| gap.is_finite() && gap > lead * 0.5) {
|
||
// Whole multiples of the auto leading add blank lines (not without limit: a far-off y
|
||
// mustn't ask for billions); other spacing is one break.
|
||
let count = (gap / lead).round().clamp(1.0, MAX_LINE_GAP);
|
||
let count = if (gap / count - lead).abs() <= lead * 0.05 { count } else { 1.0 };
|
||
breaks.push(Break { at: i, count: count as usize, leading: gap / count });
|
||
lines.push((i, ax + dx[i]));
|
||
(base, cur) = (ny, ny);
|
||
continue;
|
||
}
|
||
cur = ny;
|
||
match x[i] {
|
||
Some(ax) => targets.push((i, ax + dx[i])),
|
||
None => cells[i - 1].kern += dx[i],
|
||
}
|
||
cells[i].style.baseline_shift += base - cur;
|
||
}
|
||
// A line's characters take its spacing as leading unless it is their auto leading.
|
||
for (k, b) in breaks.iter().enumerate() {
|
||
let end = breaks.get(k + 1).map_or(n, |nb| nb.at);
|
||
if cells[b.at..end].iter().any(|c| (c.style.effective_leading() - b.leading).abs() > 0.01) {
|
||
for c in &mut cells[b.at..end] {
|
||
c.style.leading = Some(b.leading);
|
||
}
|
||
}
|
||
}
|
||
if targets.is_empty() {
|
||
let justify = match anchor {
|
||
a if a >= 1.0 => Justify::Right,
|
||
a if a > 0.0 => Justify::Center,
|
||
_ => Justify::Left,
|
||
};
|
||
return (justify, x0);
|
||
}
|
||
// Absolutely placed characters: lay the text out left-aligned and kern each one onto its x.
|
||
// SVG anchors every absolutely placed chunk on its own, so with a middle/end anchor each
|
||
// chunk's target moves back by its share of the chunk's width.
|
||
let line_of = |i: usize| lines.partition_point(|(s, _)| *s <= i) - 1;
|
||
let mut left = x0;
|
||
let mut wants: Vec<(usize, f64)> = targets.clone();
|
||
if anchor > 0.0 {
|
||
let (runs, bytes) = assemble(cells, breaks);
|
||
let lay = measure(&with_runs(runs.0));
|
||
let (pens, ends) = pens(&lay, &bytes);
|
||
// Chunk starts in order: line starts and absolutely placed characters.
|
||
let mut starts: Vec<usize> = lines.iter().map(|l| l.0).chain(targets.iter().map(|t| t.0)).collect();
|
||
starts.sort_unstable();
|
||
let width = |s: usize| {
|
||
let k = starts.partition_point(|&c| c <= s);
|
||
let e = starts.get(k).copied().unwrap_or(n);
|
||
let end = (s..e).filter_map(|j| ends[j]).fold(f64::NEG_INFINITY, f64::max);
|
||
match pens[s] {
|
||
Some(p) if end.is_finite() => end - p,
|
||
_ => 0.0,
|
||
}
|
||
};
|
||
let line_left: Vec<f64> = lines.iter().map(|&(s, lx)| lx - anchor * width(s)).collect();
|
||
left = line_left[0];
|
||
for w in &mut wants {
|
||
w.1 -= anchor * width(w.0) + line_left[line_of(w.0)];
|
||
}
|
||
} else {
|
||
for w in &mut wants {
|
||
w.1 -= lines[line_of(w.0)].1;
|
||
}
|
||
}
|
||
// Kerning changes shaping (pair kerning is off for manually kerned characters): repeat until
|
||
// every character sits on its x.
|
||
for _ in 0..4 {
|
||
let (runs, bytes) = assemble(cells, breaks);
|
||
let lay = measure(&with_runs(runs.0));
|
||
let (pens, _) = pens(&lay, &bytes);
|
||
let (mut line, mut moved, mut worst) = (usize::MAX, 0.0, 0.0f64);
|
||
for &(i, want) in &wants {
|
||
let l = line_of(i);
|
||
if l != line {
|
||
(line, moved) = (l, 0.0);
|
||
}
|
||
let (Some(p), Some(p0)) = (pens[i], pens[lines[l].0]) else { continue };
|
||
let d = want - (p - p0 + moved);
|
||
cells[i - 1].kern += d;
|
||
moved += d;
|
||
worst = worst.max(d.abs());
|
||
}
|
||
if worst < 0.01 {
|
||
break;
|
||
}
|
||
}
|
||
(Justify::Left, left)
|
||
}
|
||
|
||
/// A left-aligned point text of `runs` at the origin (for measuring).
|
||
fn with_runs(runs: Vec<TextRun>) -> TextObject {
|
||
let mut t = TextObject::point(Point::ZERO, "", CharStyle::default());
|
||
t.runs = runs;
|
||
t
|
||
}
|
||
|
||
fn point_text(cells: &[Cell]) -> TextObject {
|
||
with_runs(assemble(cells, &[]).0.0)
|
||
}
|
||
|
||
fn measure(t: &TextObject) -> TextLayout {
|
||
vectorcraft_text::layout(FontDb::global(), t)
|
||
}
|
||
|
||
/// Total advance of a laid-out single line.
|
||
fn advance(t: &TextObject) -> f64 {
|
||
measure(t).glyphs.iter().map(|g| g.advance).sum()
|
||
}
|
||
|
||
/// Pen x (start) and end x of the glyph that starts at each character's byte offset.
|
||
fn pens(lay: &TextLayout, bytes: &[usize]) -> (Vec<Option<f64>>, Vec<Option<f64>>) {
|
||
let mut at: HashMap<usize, (f64, f64)> = HashMap::with_capacity(lay.glyphs.len());
|
||
for g in &lay.glyphs {
|
||
at.entry(g.byte).or_insert((g.origin.x, g.origin.x + g.advance));
|
||
}
|
||
bytes.iter().map(|b| at.get(b).map_or((None, None), |&(s, e)| (Some(s), Some(e)))).unzip()
|
||
}
|
||
|
||
type Key = (Option<usize>, Option<usize>);
|
||
type Runs = (Vec<TextRun>, Vec<Key>);
|
||
|
||
/// Runs (and their paint indices) from the characters, with `breaks` inserted; also the byte offset
|
||
/// of each character in the text.
|
||
fn assemble(cells: &[Cell], breaks: &[Break]) -> (Runs, Vec<usize>) {
|
||
fn push((runs, keys): &mut Runs, ch: char, style: CharStyle, key: Key) {
|
||
if let Some(r) = runs.last_mut()
|
||
&& keys.last() == Some(&key)
|
||
&& r.style == style
|
||
{
|
||
r.text.push(ch);
|
||
return;
|
||
}
|
||
runs.push(TextRun { text: ch.into(), style });
|
||
keys.push(key);
|
||
}
|
||
let mut out: Runs = (vec![], vec![]);
|
||
let mut bytes = Vec::with_capacity(cells.len());
|
||
let mut off = 0;
|
||
let mut next = breaks.iter().peekable();
|
||
for (i, c) in cells.iter().enumerate() {
|
||
if let Some(b) = next.next_if(|b| b.at == i)
|
||
&& let Some(prev) = i.checked_sub(1).map(|p| &cells[p])
|
||
{
|
||
// The first newline ends the previous line; the others are blank lines `leading` apart.
|
||
let key = (prev.fill, prev.stroke);
|
||
push(&mut out, '\n', prev.final_style(), key);
|
||
let mut blank = prev.final_style();
|
||
if (blank.effective_leading() - b.leading).abs() > 0.01 {
|
||
blank.leading = Some(b.leading);
|
||
}
|
||
for _ in 1..b.count {
|
||
push(&mut out, '\n', blank.clone(), key);
|
||
}
|
||
off += b.count;
|
||
}
|
||
bytes.push(off);
|
||
off += c.ch.len_utf8();
|
||
push(&mut out, c.ch, c.final_style(), (c.fill, c.stroke));
|
||
}
|
||
(out, bytes)
|
||
}
|