Merge pull request #1585 from p0lyg0n/fix/pdf-glyph-by-glyph-strokes

PDF/.ai import: type stroked glyph by glyph stays one object

crates/pdf/src/import.rs

@@ -1241,11 +1241,50 @@ impl<'p> Builder<'p> {
     }
 
     fn flush_text(&mut self) {
-        let Some((t, opacity, facts)) = self.text.take().and_then(TextLine::finish) else { return };
-        let mut n = Node::new(self.id(), NodeKind::Text(Box::new(t)));
-        n.opacity = opacity;
-        self.lines.insert(n.id, facts);
-        self.push_node(n);
+        let Some(mut line) = self.text.take() else { return };
+        let held = std::mem::take(&mut line.held);
+        if let Some((t, opacity, facts)) = line.finish() {
+            let mut n = Node::new(self.id(), NodeKind::Text(Box::new(t)));
+            n.opacity = opacity;
+            self.lines.insert(n.id, facts);
+            self.push_node(n);
+        }
+        // The strokes of its glyphs' outlines, right after it ([`import_lines`] makes them its stroke).
+        for n in held {
+            self.push_node(n);
+        }
+    }
+
+    /// A stroke of the outline of the glyph just drawn, in the glyph's own paint, while every glyph
+    /// before it on the open line was stroked so too, is held with the line instead of ending it
+    /// (an editor writes type on a path glyph by glyph, each followed by the stroke added to the
+    /// type). `false`: it isn't one.
+    fn hold_glyph_stroke(&mut self, path: &BezPath, transform: Affine, paint: &hayro_interpret::Paint<'_>, draw_mode: &PathDrawMode) -> bool {
+        let PathDrawMode::Stroke(props) = draw_mode else { return false };
+        if self.mask.is_some() || self.blend != BlendMode::Normal || matches!(paint, hayro_interpret::Paint::Pattern(_)) {
+            return false;
+        }
+        let (p, opacity) = self.paint(paint, true);
+        let Some(line) = &self.text else { return false };
+        let Some(ink) = line.ink.last() else { return false };
+        if line.held.len() + 1 != line.ink.len() || opacity < 0.999 || !line.last_fill().is_some_and(|f| *f == p) {
+            return false;
+        }
+        let mut bp = path.clone();
+        bp.apply_affine(transform);
+        let b = bp.bounding_box();
+        let tol = 0.01 * (ink.width() + ink.height()) + 0.01;
+        if ![(b.x0, ink.x0), (b.y0, ink.y0), (b.x1, ink.x1), (b.y1, ink.y1)].iter().all(|(a, c)| (a - c).abs() <= tol) {
+            return false;
+        }
+        let mut st = stroke_layer(p, opacity, props, mean_scale(transform));
+        // Every painted path takes its turn in the scan's overprint list, a held one too.
+        st.overprint = self.path_overprint();
+        let n = Node::path(self.id(), PathData::from_bezpath(&bp), Appearance { items: vec![AppearanceItem::Stroke(st)], ..Default::default() });
+        if let Some(line) = &mut self.text {
+            line.held.push(n);
+        }
+        true
     }
 
     /// Convert a hayro paint to a VectorCraft paint and opacity (`stroke`: for a stroke).
@@ -1667,6 +1706,10 @@ impl<'a> Device<'a> for Builder<'_> {
 
     fn draw_path(&mut self, path: &BezPath, transform: Affine, paint: &hayro_interpret::Paint<'a>, draw_mode: &PathDrawMode) {
         self.flush_glyphs();
+        if self.hold_glyph_stroke(path, transform, paint, draw_mode) {
+            self.pending = false;
+            return;
+        }
         self.flush_text();
         self.pending = false;
         let overprint = self.path_overprint();

crates/pdf/src/import_text.rs

@@ -11,7 +11,7 @@ use std::collections::HashMap;
 
 use kurbo::{Affine, BezPath, Point, Rect, Vec2};
 use vectorcraft_color::Paint;
-use vectorcraft_doc::{CharStyle, ParaDirection, TextKind, TextObject, TextRun};
+use vectorcraft_doc::{CharStyle, Node, ParaDirection, TextKind, TextObject, TextRun};
 use vectorcraft_text::TextLayout;
 
 /// One glyph's placement: its baseline origin, advance direction, size and horizontal scale.
@@ -144,6 +144,9 @@ pub(crate) struct TextLine {
     gaps: Vec<(usize, f64)>,
     /// Each glyph's advance in the file's font (points), with [`Self::baseline`].
     advances: Vec<f64>,
+    /// The strokes of its glyphs' outlines drawn between them, one per glyph with ink so far
+    /// (written right after the line).
+    pub held: Vec<Node>,
 }
 
 /// What a finished line of type tells beyond its text object (see [`crate::import_lines`]).
@@ -177,9 +180,15 @@ impl TextLine {
             ink: vec![],
             gaps: vec![],
             advances: vec![],
+            held: vec![],
         }
     }
 
+    /// The paint the last glyph is filled with.
+    pub fn last_fill(&self) -> Option<&Paint> {
+        self.runs.last()?.0.fill.as_ref()
+    }
+
     /// Add glyph `text` set vertically (`upright`) if it continues this column (or makes this
     /// line's single glyph a column): below the last one, in the same column. `false`: it starts
     /// another line.

crates/pdf/src/tests_import_lines.rs

@@ -153,6 +153,25 @@ fn a_stroke_on_the_type_of_a_moved_ai_page_is_still_the_types_stroke() {
     assert!(matches!(art[1].appearance.items.as_slice(), [AppearanceItem::Stroke(_)]), "{:?}", art[1].appearance);
 }
 
+#[test]
+fn glyphs_each_followed_by_their_stroked_outline_stay_one_object() {
+    // Type on a path is written glyph by glyph: each glyph, then its outline stroked in the same
+    // colour (a shadow under the type).
+    let glyph = |c: char, x: f64, stroke: &str| format!("BT 0 0 1 rg /F1 24 Tf {x} 50 Td ({c}) Tj ET {stroke} 0.5 w {}", outline(c, x));
+    let i_at = 10.0 + 0.722 * 24.0;
+    let d = import(&page(&(glyph('H', 10.0, "0 0 1 RG") + &glyph('i', i_at, "0 0 1 RG")))).unwrap();
+    let art = d.layers[0].children().unwrap();
+    assert_eq!(art.len(), 1, "one object: {art:?}");
+    let NodeKind::Text(t) = &art[0].kind else { panic!("{:?}", art[0].kind) };
+    assert_eq!(t.plain_text(), "Hi");
+    let [AppearanceItem::Stroke(st)] = art[0].appearance.items.as_slice() else { panic!("{:?}", art[0].appearance) };
+    assert_eq!(st.paint.color(), Some(Color::rgb(0.0, 0.0, 1.0)));
+    // A stroke of another colour drawn over each glyph in turn would also cover the next one's
+    // neighbour as one object's stroke: the glyphs stay as the file draws them.
+    let d = import(&page(&(glyph('H', 10.0, "1 1 1 RG") + &glyph('i', i_at, "1 1 1 RG")))).unwrap();
+    assert_eq!(texts(&d).len(), 2);
+}
+
 /// A 300 × 200 pt page with `lines` of (x, y from the top, size, text) in Source Sans 3.
 fn source_sans(lines: &[(f32, f32, f32, &str)]) -> Vec<u8> {
     crate::tests_live_text::text_pdf(lines, false)