M4: a dashed line starts and ends with a half-length dash (#1718)

ROADMAP.md

@@ -2,7 +2,7 @@
 
 **Stage: alpha** · next: beta, ~26 points and ~162–292 h away (one Opus 5.5 agent; ~33–67 h wall-clock with 5 agents)
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-30 · **Change:** minor (the Pages, Layers and Assets search fields keep their text in the middle of the field (#1703); a board connector's path can be reshaped by dragging its path handles (#1710); boards have 16 more shapes (arrows, polygons, star, plus and flowchart symbols), in pickers that lay them out in a grid; library analytics count insertions and show insertions and detachments over the past 30 days, 90 days or year; a stroke's Custom style takes a dash pattern of any length as a comma-separated list (#1681); a control request can set its own timeout, up to 10 minutes (`timeoutMs`; `figcraft-cli mcp --attach PORT --timeout SECONDS`) (#1696); gap 6: a widget opens its plugin's panel (plugin API 5), whose callbacks redraw it; the keyboard's Menu key opens the context menu, as Shift+F10 does; an Open link action can open in place of the prototype, with "Open in new tab" off (gap 15); a collection of this file can be extended (Extend collection on its row, `variable.extendCollection`), its extension following its edits at once, and extended collections extend again in the file; the eyedropper with Cmd/Ctrl+Shift makes a colour style or variable of what it picks; a live session's welcome sends the document compressed to clients that read it, about seven times smaller (#1665); a control request that times out says truthfully whether it was dropped or is still running and will take effect, and only screenshots and input blame the window (#1673); a board keeps earlier votes' results, listed newest first in Results and deleted one at a time; the object a stamp will stick to is outlined while the stamp tool is over it or a stamp is dragged over it, and board objects take no drops (gap 24); a server can list the files shared from it now for everyone who reaches it, Home ▸ Online shows them and their links carry no secret (`team_files`, part of #742); team library analytics count detached instances per component and file (gap 10); skipping the Open link notice by command is saved with the preferences at once (gap 15); a selected connector's bar on a board sets its start and end points, solid or dashed, its weight and any colour (#1596); cells copied from a spreadsheet paste onto a board as a table; a long layer name stays on one line in the Export button and the Dev Mode header, ending with an ellipsis, and no longer covers the Design panel (#1650); with hundreds of layers selected, the Design panel and the selection overlays stop going over the whole selection on every frame, so dragging 648 layers averages about 1.1 ms of UI per frame (#1571); plugin panels show pictures: an `image` control, base64 within 256 KB and 4,096 px a side, named by its label (gap 6); `.fig` connector labels without a saved snapshot are kept, centred on their line (gap 1); a drag moving many layers re-runs only what sits around them, not each layer's bindings, sizing, text and instance checks, on every move (#1571); damaged font tracking table offsets are checked instead of wrapping on 32-bit targets, and font indexing makes its existing offset bounds explicit (#1125); Bosnian (`bs`) draft catalog; text style dedupe is O(spans) via a last-two cache and fingerprint buckets (#1102); pasted layers whose image the clipboard lacks are named and show a placeholder that reads as missing (#1646); paint-style colours on layers pasted from another design app keep their style instead of turning black (#1638); progress docs cleaned of what merges left twice: rows merged into one, repeated status items removed, and `cargo xtask docs` (in `ci`) fails on a repeated table row or status item; a name typed for a variable or collection finds the one with that exact id before one named like it, and stored mode ids, font family variables and the panels' labels read exact ids (#1613); plugin widgets have hover styles: a layer's `hover` fill, stroke, opacity or text colour shows while the pointer is over it (gap 6); `.fig` elbowed and curved connectors without a saved path are routed like board connectors instead of drawn straight (gap 1); every file a command reads whole by path is a regular file within a cap that fits it: documents 16 GiB, placed images 256 MiB, CLI scripts 1 GiB; `figcraft-cli connect publish` publishes a code repository's code connect mappings to a design file (gap 16); while a drag only moves a large selection, its outlines, box, slots, spacing and Design panel values are worked out once and shifted, not rebuilt on every move (#1571); Shift+Cmd/Ctrl+Enter on a selected board shape adds the next shape already joined to it, and goes on typing (#1597); an imported or pasted file finds an installed family under the other names its fonts give it, and with other case and spacing, instead of reporting it missing (#1292); a development example generates figcraft-cli's shell completions and man pages from its clap definitions (part of #1396); `.fig` ZIP image reads share a totalLine truncated
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-30 · **Change:** minor (a dashed line starts and ends with a half-length dash, on the canvas and in exports; the Pages, Layers and Assets search fields keep their text in the middle of the field (#1703); a board connector's path can be reshaped by dragging its path handles (#1710); boards have 16 more shapes (arrows, polygons, star, plus and flowchart symbols), in pickers that lay them out in a grid; library analytics count insertions and show insertions and detachments over the past 30 days, 90 days or year; a stroke's Custom style takes a dash pattern of any length as a comma-separated list (#1681); a control request can set its own timeout, up to 10 minutes (`timeoutMs`; `figcraft-cli mcp --attach PORT --timeout SECONDS`) (#1696); gap 6: a widget opens its plugin's panel (plugin API 5), whose callbacks redraw it; the keyboard's Menu key opens the context menu, as Shift+F10 does; an Open link action can open in place of the prototype, with "Open in new tab" off (gap 15); a collection of this file can be extended (Extend collection on its row, `variable.extendCollection`), its extension following its edits at once, and extended collections extend again in the file; the eyedropper with Cmd/Ctrl+Shift makes a colour style or variable of what it picks; a live session's welcome sends the document compressed to clients that read it, about seven times smaller (#1665); a control request that times out says truthfully whether it was dropped or is still running and will take effect, and only screenshots and input blame the window (#1673); a board keeps earlier votes' results, listed newest first in Results and deleted one at a time; the object a stamp will stick to is outlined while the stamp tool is over it or a stamp is dragged over it, and board objects take no drops (gap 24); a server can list the files shared from it now for everyone who reaches it, Home ▸ Online shows them and their links carry no secret (`team_files`, part of #742); team library analytics count detached instances per component and file (gap 10); skipping the Open link notice by command is saved with the preferences at once (gap 15); a selected connector's bar on a board sets its start and end points, solid or dashed, its weight and any colour (#1596); cells copied from a spreadsheet paste onto a board as a table; a long layer name stays on one line in the Export button and the Dev Mode header, ending with an ellipsis, and no longer covers the Design panel (#1650); with hundreds of layers selected, the Design panel and the selection overlays stop going over the whole selection on every frame, so dragging 648 layers averages about 1.1 ms of UI per frame (#1571); plugin panels show pictures: an `image` control, base64 within 256 KB and 4,096 px a side, named by its label (gap 6); `.fig` connector labels without a saved snapshot are kept, centred on their line (gap 1); a drag moving many layers re-runs only what sits around them, not each layer's bindings, sizing, text and instance checks, on every move (#1571); damaged font tracking table offsets are checked instead of wrapping on 32-bit targets, and font indexing makes its existing offset bounds explicit (#1125); Bosnian (`bs`) draft catalog; text style dedupe is O(spans) via a last-two cache and fingerprint buckets (#1102); pasted layers whose image the clipboard lacks are named and show a placeholder that reads as missing (#1646); paint-style colours on layers pasted from another design app keep their style instead of turning black (#1638); progress docs cleaned of what merges left twice: rows merged into one, repeated status items removed, and `cargo xtask docs` (in `ci`) fails on a repeated table row or status item; a name typed for a variable or collection finds the one with that exact id before one named like it, and stored mode ids, font family variables and the panels' labels read exact ids (#1613); plugin widgets have hover styles: a layer's `hover` fill, stroke, opacity or text colour shows while the pointer is over it (gap 6); `.fig` elbowed and curved connectors without a saved path are routed like board connectors instead of drawn straight (gap 1); every file a command reads whole by path is a regular file within a cap that fits it: documents 16 GiB, placed images 256 MiB, CLI scripts 1 GiB; `figcraft-cli connect publish` publishes a code repository's code connect mappings to a design file (gap 16); while a drag only moves a large selection, its outlines, box, slots, spacing and Design panel values are worked out once and shifted, not rebuilt on every move (#1571); Shift+Cmd/Ctrl+Enter on a selected board shape adds the next shape already joined to it, and goes on typing (#1597); an imported or pasted file finds an installed family under the other names its fonts give it, and with other case and spacing, instead of reporting it missing (#1292); a development example generates figcraft-cli's shell completions and man Line truncated
 
 FigCraft is a clean-room, open-source, pure-Rust reimplementation of the Figma design workflow,
 native on macOS, Windows, Linux and FreeBSD and in the browser, fully drivable by agents through
@@ -358,6 +358,7 @@ Ranked; detail and milestones in [`docs/roadmap.md`](docs/roadmap.md).
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-31 | patch | M4: an open dashed line starts and ends with a half-length dash, with a whole number of patterns fitted to it (dashes and gaps scaled together), for Dash and Custom patterns, on the canvas, in PNG, PDF and SVG (`stroke-dashoffset`) and in Outline stroke. Closed paths are unchanged. An imported SVG's open dashed line follows the same rule. |
 | 2026-10-31 | patch | M8, #1703: the search fields in the Pages, Layers and Assets panels keep their text in the middle of the field. It hung 5 points low in Pages and Layers and 2 in Assets, in every file: the editor was laid out in a box one line tall, shorter than the theme's least height for an editor. All three now share `widgets::search_box`, on the editor the other text fields use. |
 | 2026-10-31 | minor | M12, #1710: a selected elbow or curved connector shows path handles. Dragging a run moves it and a first or last run gains an extra run to stay on its end; a curve's middle goes where it is dragged (`board.reshape`, one undo step). The shape travels with what the connector joins, is saved with the file, and goes back to routing itself when the style changes or an end moves to something else. |
 | 2026-10-31 | minor | M12: boards have 23 shapes with text instead of 7: triangle down, parallelogram right and left, trapezoid, pentagon, hexagon, octagon, star, plus, arrow left and right, and the flowchart symbols database, document, predefined process, manual input and internal storage. The toolbar flyout wraps into rows of eight and the selection bar's shape menu is a grid of outlines named on hover. The stale "Quick-create handles: missing" row now says what exists. |

crates/pathops/src/dash_ends_tests.rs

@@ -0,0 +1,114 @@
+//! A dashed line starts and ends with a half-length dash, whatever its pattern: a whole number of
+//! patterns fits the line, dashes and gaps scaled together. A closed path has no ends and runs its
+//! pattern as it is. The numbers in [`the_public_example_comes_out_the_same`] are from a public
+//! explanation of how the fit works.
+
+use figcraft_doc::{StrokeAlign, StrokeProps, WidthProfile};
+use figcraft_geom::Point;
+use figcraft_geom::kurbo::{BezPath, Rect, Shape};
+
+use crate::width::{dash_pattern, line_dashes, subpath_dashes};
+use crate::{stroke_center, stroke_outline};
+
+fn line(len: f64) -> BezPath {
+    let mut p = BezPath::new();
+    p.move_to((0.0, 0.0));
+    p.line_to((len, 0.0));
+    p
+}
+
+fn dashed(dashes: &[f64]) -> StrokeProps {
+    StrokeProps { weight: 2.0, dashes: dashes.to_vec(), align: StrokeAlign::Center, ..Default::default() }
+}
+
+fn covers(p: &BezPath, x: f64) -> bool {
+    p.winding(Point::new(x, 0.0)) != 0
+}
+
+/// Which of `xs` are on a dash.
+fn on(p: &BezPath, xs: &[f64]) -> Vec<bool> {
+    xs.iter().map(|x| covers(p, *x)).collect()
+}
+
+#[test]
+fn a_line_starts_and_ends_with_half_a_dash() {
+    // 10 on, 10 off along 100: 5 on, 10 off, 10 on, … 10 off, 5 on.
+    let s = stroke_center(&line(100.0), 2.0, &dashed(&[10.0, 10.0]));
+    assert_eq!(
+        on(&s, &[2.0, 7.0, 13.0, 16.0, 24.0, 26.0, 84.0, 86.0, 94.0, 98.0]),
+        [true, false, false, true, true, false, true, false, false, true]
+    );
+    assert!((s.area().abs() - 100.0).abs() < 0.01, "half of it is dashes: {}", s.area());
+}
+
+#[test]
+fn a_whole_number_of_patterns_fits_the_line() {
+    // 107 is 5 patterns and a bit: scaled to 21.4 each, so it still ends on half a dash.
+    let (pattern, offset) = line_dashes(107.0, false, &[10.0, 10.0]);
+    assert!((pattern[0] - 10.7).abs() < 1e-9 && (pattern[1] - 10.7).abs() < 1e-9, "{pattern:?}");
+    assert!((offset - 5.35).abs() < 1e-9);
+    let s = stroke_center(&line(107.0), 2.0, &dashed(&[10.0, 10.0]));
+    assert_eq!(on(&s, &[5.0, 6.0, 101.0, 102.0]), [true, false, false, true]);
+    // A line shorter than one pattern takes one, scaled down.
+    assert_eq!(line_dashes(5.0, false, &[10.0, 10.0]), (vec![2.5, 2.5], 1.25));
+    // A pattern that already fits isn't lost to rounding.
+    assert_eq!(line_dashes(0.3, false, &[0.1, 0.05]).0.len(), 2);
+    let (fitted, _) = line_dashes(3.0 * 0.15, false, &[0.1, 0.05]);
+    assert!((fitted[0] - 0.1).abs() < 1e-9, "three patterns, not two: {fitted:?}");
+}
+
+#[test]
+fn the_public_example_comes_out_the_same() {
+    // A 19 px line of [1, 2] draws six patterns of about 3.167.
+    let (pattern, offset) = line_dashes(19.0, false, &[1.0, 2.0]);
+    assert!((pattern[0] - 1.056).abs() < 1e-3 && (pattern[1] - 2.111).abs() < 1e-3, "{pattern:?}");
+    assert!((offset - 0.528).abs() < 1e-3);
+}
+
+/// Custom patterns too: the half is of the first dash, which the pattern comes round to at the end.
+#[test]
+fn a_custom_pattern_ends_on_half_its_first_dash() {
+    let s = stroke_center(&line(100.0), 2.0, &dashed(&[12.0, 4.0, 2.0, 2.0]));
+    // 6 on, 4 off, 2 on, 2 off, 12 on, …, and the last 6 on.
+    assert_eq!(on(&s, &[3.0, 8.0, 11.0, 13.0, 20.0, 97.0, 93.0]), [true, false, true, false, true, true, false]);
+    // An odd pattern draws repeated, so it fits as the doubled one.
+    let doubled = dash_pattern(&dashed(&[4.0, 2.0, 1.0])).unwrap();
+    assert_eq!(doubled, [4.0, 2.0, 1.0, 4.0, 2.0, 1.0]);
+    let s = stroke_center(&line(70.0), 2.0, &dashed(&[4.0, 2.0, 1.0]));
+    assert_eq!(on(&s, &[1.0, 3.0, 67.5, 69.0]), [true, false, false, true], "half of 4 at each end");
+}
+
+#[test]
+fn a_closed_path_runs_its_pattern_as_it_is() {
+    let rect = Rect::new(0.0, 0.0, 100.0, 50.0).to_path(0.1);
+    assert_eq!(subpath_dashes(&rect, &[10.0, 7.0]), (vec![10.0, 7.0], 0.0));
+    // The open one measures the same and is fitted.
+    let (open, offset) = line_dashes(300.0, false, &[10.0, 7.0]);
+    assert!(open[0] != 10.0 && offset > 0.0);
+}
+
+#[test]
+fn each_subpath_fits_the_pattern_to_its_own_length() {
+    let mut two = line(100.0);
+    two.move_to((0.0, 50.0));
+    two.line_to((107.0, 50.0));
+    let s = stroke_center(&two, 2.0, &dashed(&[10.0, 10.0]));
+    assert!(s.winding(Point::new(98.0, 0.0)) != 0 && s.winding(Point::new(102.0, 50.0)) != 0, "both end on half a dash");
+    assert!(s.winding(Point::new(92.0, 0.0)) == 0 && s.winding(Point::new(99.0, 50.0)) == 0);
+}
+
+/// A variable-width stroke is drawn by its own code: its dashes land in the same places.
+#[test]
+fn a_variable_width_stroke_dashes_the_same_way() {
+    let props = StrokeProps { width_profile: Some(WidthProfile::uniform()), ..dashed(&[10.0, 10.0]) };
+    let s = stroke_outline(&line(100.0), &props, false);
+    assert_eq!(on(&s, &[2.0, 7.0, 13.0, 16.0, 98.0]), [true, false, false, true, true]);
+}
+
+/// Nothing to fit: an empty line or a pattern of nothing stays as it is.
+#[test]
+fn nothing_to_fit_stays_as_it_is() {
+    assert_eq!(line_dashes(0.0, false, &[10.0, 10.0]), (vec![10.0, 10.0], 0.0));
+    assert_eq!(line_dashes(100.0, false, &[0.0, 0.0]), (vec![0.0, 0.0], 0.0));
+    assert!(stroke_center(&BezPath::new(), 2.0, &dashed(&[10.0, 10.0])).elements().is_empty());
+}

crates/pathops/src/lib.rs

@@ -16,6 +16,8 @@ mod budget;
 #[cfg(test)]
 mod budget_tests;
 #[cfg(test)]
+mod dash_ends_tests;
+#[cfg(test)]
 mod dot_dash_tests;
 #[cfg(test)]
 mod ops_tests;
@@ -337,7 +339,7 @@ pub fn stroke_center(path: &BezPath, width: f64, props: &StrokeProps) -> BezPath
         return BezPath::new();
     }
     let width = width.min(MAX_STROKE_WIDTH);
-    let mut style = kurbo::Stroke::new(width)
+    let style = kurbo::Stroke::new(width)
         .with_join(kjoin(props.join))
         .with_miter_limit(props.miter_limit.clamp(1.0, 100.0))
         .with_start_cap(kcap(props.cap_start))
@@ -346,10 +348,17 @@ pub fn stroke_center(path: &BezPath, width: f64, props: &StrokeProps) -> BezPath
     let subpaths = path.elements().iter().filter(|e| matches!(e, PathEl::MoveTo(_))).count() as f64;
     let round = [props.cap_start, props.cap_end].into_iter().any(|c| matches!(kcap(c), Cap::Round));
     let pattern = width::dash_pattern(props).map(|p| p.into_iter().map(|d| if round && d == 0.0 { 1e-3 } else { d }).collect::<Vec<_>>());
-    if let Some(pat) = pattern.filter(|p| width::dashes_fit(path.perimeter(1.0) + subpaths * p.iter().sum::<f64>(), p)) {
-        style = style.with_dashes(0.0, pat);
+    let opts = kurbo::StrokeOpts::default();
+    let Some(pat) = pattern.filter(|p| width::dashes_fit(path.perimeter(1.0) + subpaths * p.iter().sum::<f64>(), p)) else {
+        return kurbo::stroke(path.iter(), &style, &opts, 0.05);
+    };
+    // Each subpath fits the pattern to its own length.
+    let mut out = BezPath::new();
+    for sub in figcraft_geom::split_subpaths(path) {
+        let (dashes, offset) = width::subpath_dashes(&sub, &pat);
+        out.extend(kurbo::stroke(sub.iter(), &style.clone().with_dashes(offset, dashes), &opts, 0.05));
     }
-    kurbo::stroke(path.iter(), &style, &kurbo::StrokeOpts::default(), 0.05)
+    out
 }
 
 /// The painted stroke area of a shape as a fill path (local coordinates). `closed` says whether the

crates/pathops/src/width.rs

@@ -8,7 +8,7 @@
 //! fill it with the non-zero rule.
 
 use figcraft_doc::{StrokeCap, StrokeJoin, StrokeProps, WidthProfile};
-use figcraft_geom::kurbo::{self, BezPath, Point, Vec2};
+use figcraft_geom::kurbo::{self, BezPath, PathEl, Point, Shape as _, Vec2};
 use figcraft_geom::measure::FLATTEN_TOL;
 /// The most points the outline works with; longer paths fall back to a uniform stroke.
 pub use figcraft_geom::measure::MAX_SAMPLES as MAX_WIDTH_SAMPLES;
@@ -193,11 +193,12 @@ fn outline_piece(path: &mut BezPath, pts: &[Point], hw: &[Half], closed: bool, s
     push_contour(path, ring);
 }
 
-/// Split a sampled polyline into dashes (`pattern` alternates dash and gap lengths).
-fn dashes(pts: &[Point], hw: &[Half], pattern: &[f64]) -> Vec<(Vec<Point>, Vec<Half>)> {
+/// Split a sampled polyline into dashes (`pattern` alternates dash and gap lengths), `offset` into
+/// the pattern at its start.
+fn dashes(pts: &[Point], hw: &[Half], pattern: &[f64], offset: f64) -> Vec<(Vec<Point>, Vec<Half>)> {
     let mut out = Vec::new();
     let Some(&first) = pattern.first() else { return out };
-    let (mut idx, mut left, mut on) = (0usize, first, true);
+    let (mut idx, mut left, mut on) = (0usize, (first - offset).max(0.0), true);
     let mut cur: (Vec<Point>, Vec<Half>) = (pts.iter().take(1).copied().collect(), hw.iter().take(1).copied().collect());
     for (p, h) in pts.windows(2).zip(hw.windows(2)) {
         let (a, b, ha, hb) = (p[0], p[1], h[0], h[1]);
@@ -242,6 +243,32 @@ pub fn dash_pattern(props: &StrokeProps) -> Option<Vec<f64>> {
     Some(if dashes.len() % 2 == 1 { [dashes.clone(), dashes].concat() } else { dashes })
 }
 
+/// How a line `len` long draws `pattern` (from [`dash_pattern`]): the pattern and how far into it
+/// the line starts. An open line starts and ends with a half-length dash, so a whole number of
+/// patterns fits it exactly, dashes and gaps scaled together, and it starts halfway through the
+/// first dash. A closed line has no ends: it runs the pattern as it is.
+pub fn line_dashes(len: f64, closed: bool, pattern: &[f64]) -> (Vec<f64>, f64) {
+    let total: f64 = pattern.iter().sum();
+    if closed || !(len > 1e-9 && total > 0.0) {
+        return (pattern.to_vec(), 0.0);
+    }
+    // A hair under a whole number is that number: a pattern already fitted stays as it is, also
+    // after a trip through a file that rounds it.
+    let scale = len / ((len / total + 0.01).floor().max(1.0) * total);
+    let fitted: Vec<f64> = pattern.iter().map(|d| d * scale).collect();
+    let offset = fitted.first().map_or(0.0, |d| d / 2.0);
+    (fitted, offset)
+}
+
+/// [`line_dashes`] for a subpath.
+pub fn subpath_dashes(sub: &BezPath, pattern: &[f64]) -> (Vec<f64>, f64) {
+    let closed = matches!(sub.elements().last(), Some(PathEl::ClosePath));
+    line_dashes(sub.perimeter(DASH_ACCURACY), closed, pattern)
+}
+
+/// How exactly a subpath is measured to fit its dashes (the stroke's own tolerance).
+const DASH_ACCURACY: f64 = 0.05;
+
 /// Whether `pattern` (from [`dash_pattern`]) makes at most [`MAX_DASHES`] dashes along `len`;
 /// past that a stroke draws solid instead of one outline per dash (#1060).
 pub(crate) fn dashes_fit(len: f64, pattern: &[f64]) -> bool {
@@ -301,7 +328,8 @@ pub fn variable_outline(path: &BezPath, width: f64, props: &StrokeProps, profile
             .collect();
         match &pattern {
             Some(pat) if dashes_fit(len, pat) => {
-                for (p, h) in dashes(&pts, &hw, pat) {
+                let (pat, offset) = line_dashes(len, line.closed, pat);
+                for (p, h) in dashes(&pts, &hw, &pat, offset) {
                     outline_piece(&mut out, &p, &h, false, style);
                 }
             }

crates/pathops/src/width_tests.rs

@@ -104,11 +104,11 @@ fn joins_and_dashes() {
     let dashed = StrokeProps { dashes: vec![10.0, 10.0], ..props(2.0, Some(WidthProfile::uniform())) };
     let s = stroke_outline(&line(100.0), &dashed, false);
     assert!((s.area().abs() - 100.0).abs() < 1.0, "{}", s.area());
-    assert!(covers(&s, 5.0, 0.0) && !covers(&s, 15.0, 0.0));
+    assert!(covers(&s, 2.0, 0.0) && !covers(&s, 10.0, 0.0) && covers(&s, 20.0, 0.0));
     // Dashes keep the width of where they are on the path.
     let tapered = StrokeProps { dashes: vec![10.0, 10.0], ..props(10.0, WidthPreset::Wedge.profile()) };
     let s = stroke_outline(&line(100.0), &tapered, false);
-    assert!(covers(&s, 5.0, 4.0) && !covers(&s, 85.0, 4.0));
+    assert!(covers(&s, 2.0, 4.0) && !covers(&s, 80.0, 4.0));
     // Zero-length dashes with round caps are dots.
     let dots =
         StrokeProps { dashes: vec![0.0, 10.0], cap_start: StrokeCap::Round, cap_end: StrokeCap::Round, ..props(4.0, Some(WidthProfile::uniform())) };

crates/svg/src/import.rs

@@ -529,7 +529,11 @@ pub(crate) fn stroke_props(s: &usvg::Stroke, k: f64) -> figcraft_doc::StrokeProp
     };
     let mut dashes: Vec<f64> = s.dasharray().unwrap_or(&[]).iter().map(|v| f64::from(*v) * k).collect();
     if !dashes.is_empty() {
-        dashes = dash_offset(&dashes, f64::from(s.dashoffset()) * k, cap == StrokeCap::None).unwrap_or(dashes);
+        let offset = f64::from(s.dashoffset()) * k;
+        // Half a dash in is how a line starts by itself (and how export writes one).
+        if dashes.first().is_none_or(|d| (d / 2.0 - offset).abs() > 1e-3) {
+            dashes = dash_offset(&dashes, offset, cap == StrokeCap::None).unwrap_or(dashes);
+        }
     }
     figcraft_doc::StrokeProps {
         weight: f64::from(s.width().get()) * k,

crates/svg/src/lib.rs

@@ -138,6 +138,20 @@ fn path_d(p: &BezPath) -> String {
     s
 }
 
+/// A stroke's path as `d` values, each with its dash attributes. A dashed one takes a `<path>` for
+/// each subpath, as each fits the pattern to its own length (see
+/// [`figcraft_pathops::width::line_dashes`]), so a viewer draws what the canvas does.
+fn dashed_pieces(path: BezPath, k: &figcraft_doc::StrokeProps) -> Vec<(String, String)> {
+    let list = |v: &[f64]| v.iter().map(|d| num(*d)).collect::<Vec<_>>().join(" ");
+    let Some(pattern) = figcraft_pathops::width::dash_pattern(k) else { return vec![(path_d(&path), String::new())] };
+    let piece = |sub: BezPath| {
+        let (dashes, offset) = figcraft_pathops::width::subpath_dashes(&sub, &pattern);
+        let start = if offset > 0.0 { format!(" stroke-dashoffset=\"{}\"", num(offset)) } else { String::new() };
+        (path_d(&sub), format!(" stroke-dasharray=\"{}\"{start}", list(&dashes)))
+    };
+    figcraft_geom::split_subpaths(&path).into_iter().map(piece).collect()
+}
+
 /// A matrix scale/shear coefficient to 6 significant digits (unlike [`num`], small values survive).
 fn coeff(v: f64) -> String {
     if !v.is_finite() || v == 0.0 {
@@ -816,22 +830,15 @@ impl W<'_> {
             StrokeJoin::Round => " stroke-linejoin=\"round\"".into(),
             StrokeJoin::Bevel => " stroke-linejoin=\"bevel\"".into(),
         };
-        let dash = if k.dashes.is_empty() {
-            String::new()
-        } else {
-            format!(" stroke-dasharray=\"{}\"", k.dashes.iter().map(|d| num(*d)).collect::<Vec<_>>().join(" "))
-        };
+        let pieces = dashed_pieces(path, k);
         let mut out = String::new();
         for p in &n.strokes {
             if let Some(a) = self.paint_attr(p, n.width, n.height) {
                 let a = a.replace("fill-opacity=", "stroke-opacity=").replacen("fill=", "stroke=", 1);
-                let _ = write!(
-                    out,
-                    "<path transform=\"{}\" d=\"{}\" fill=\"none\" {a} stroke-width=\"{}\"{cap}{join}{dash}/>",
-                    matrix(xf),
-                    path_d(&path),
-                    num(w)
-                );
+                for (d, dash) in &pieces {
+                    let _ =
+                        write!(out, "<path transform=\"{}\" d=\"{d}\" fill=\"none\" {a} stroke-width=\"{}\"{cap}{join}{dash}/>", matrix(xf), num(w));
+                }
             }
         }
         Some(out)

crates/svg/src/tests.rs

@@ -324,3 +324,61 @@ fn matrix_snaps_rotation_noise_and_tiny_values() {
     assert_eq!(matrix(r), "matrix(0 1 -1 0 0 0)");
     assert_eq!(matrix(Affine::scale(1e-320)), "matrix(0 0 0 0 0 0)");
 }
+
+/// A dashed stroke's `<path>`s in `svg`, each as (dash pattern, dash offset).
+fn dash_attrs(svg: &str) -> Vec<(String, Option<String>)> {
+    let attr = |e: &str, name: &str| e.split(&format!(" {name}=\"")).nth(1).and_then(|r| r.split('"').next()).map(str::to_string);
+    svg.split("<path").filter_map(|e| Some((attr(e, "stroke-dasharray")?, attr(e, "stroke-dashoffset")))).collect()
+}
+
+/// A page with one centred dashed stroke along `network`'s path or around a rectangle.
+fn dashed(kind: NodeKind, dashes: Vec<f64>) -> String {
+    let mut d = Document::new("dashes");
+    let p = d.first_page().unwrap();
+    let n = d.create(p, kind, "Dashed", 0.0, 0.0, 100.0, 50.0).unwrap();
+    let node = d.get_mut(n).unwrap();
+    node.fills.clear();
+    node.strokes = vec![Paint::solid(Color::from_hex("000000").unwrap())];
+    node.stroke.align = figcraft_doc::StrokeAlign::Center;
+    node.stroke.dashes = dashes;
+    export_svg(&d, &[n], &SvgOptions { simplify_stroke: true, ..SvgOptions::default() }).unwrap()
+}
+
+/// A viewer draws what the canvas does: an open line's dashes fitted and started half a dash in.
+#[test]
+fn a_dashed_line_exports_as_the_canvas_draws_it() {
+    let line = Segment::line(0, 1);
+    let open = VectorNetwork { vertices: vec![Vertex::new(0.0, 0.0), Vertex::new(107.0, 0.0)], segments: vec![line], ..Default::default() };
+    let svg = dashed(NodeKind::Vector { network: open }, vec![10.0, 10.0]);
+    assert_eq!(dash_attrs(&svg), [("10.7 10.7".to_string(), Some("5.35".to_string()))], "{svg}");
+}
+
+#[test]
+fn a_closed_dashed_path_exports_its_pattern_as_it_is() {
+    let svg = dashed(NodeKind::Rectangle, vec![10.0, 7.0]);
+    assert_eq!(dash_attrs(&svg), [("10 7".to_string(), None)], "{svg}");
+}
+
+/// Each subpath fits the pattern to its own length, so each is a `<path>` of its own.
+#[test]
+fn each_subpath_of_a_dashed_vector_exports_its_own_fit() {
+    let two = VectorNetwork {
+        vertices: vec![Vertex::new(0.0, 0.0), Vertex::new(100.0, 0.0), Vertex::new(0.0, 20.0), Vertex::new(107.0, 20.0)],
+        segments: vec![Segment::line(0, 1), Segment::line(2, 3)],
+        ..Default::default()
+    };
+    let svg = dashed(NodeKind::Vector { network: two }, vec![10.0, 10.0]);
+    assert_eq!(dash_attrs(&svg).len(), 2, "{svg}");
+}
+
+/// What export writes opens as the same line, the offset not counted twice.
+#[test]
+fn an_exported_dashed_line_opens_as_the_same_line() {
+    let src = r##"<svg xmlns="http://www.w3.org/2000/svg" width="200" height="20"><line x2="107" stroke="#000" stroke-dasharray="10.7 10.7" stroke-dashoffset="5.35"/></svg>"##;
+    let mut d = Document::new("back");
+    let p = d.first_page().unwrap();
+    let frame = import_svg(&mut d, src.as_bytes(), p, 0.0, 0.0, "Back").unwrap();
+    let dashes: Vec<Vec<f64>> =
+        d.subtree(frame).iter().filter_map(|i| d.node(*i)).filter(|n| !n.stroke.dashes.is_empty()).map(|n| n.stroke.dashes.clone()).collect();
+    assert!(matches!(dashes.as_slice(), [d] if d.len() == 2 && d.iter().all(|v| (v - 10.7).abs() < 1e-4)), "{dashes:?}");
+}

crates/svg/tests/corpus/strokes.svg

@@ -7,9 +7,10 @@
   <polyline id="miter" points="20,100 50,70 80,100" fill="none" stroke="#000000" stroke-width="10" stroke-miterlimit="4"/>
   <polyline id="round-join" points="90,100 120,70 150,100" fill="none" stroke="#000000" stroke-width="10" stroke-linejoin="round"/>
   <polyline id="bevel" points="160,100 190,70 220,100" fill="none" stroke="#000000" stroke-width="10" stroke-linejoin="bevel"/>
+  <!-- A dashed line starts and ends with half a dash: 10 on, 10 off, 20 on, 10 off, … -->
   <!-- probe 15 10 #000000ff -->
-  <!-- probe 35 10 #00000000 -->
-  <!-- probe 45 10 #000000ff -->
+  <!-- probe 25 10 #00000000 -->
+  <!-- probe 40 10 #000000ff -->
   <!-- probe 16 40 #ff0000ff -->
   <!-- probe 63 40 #ff0000ff -->
   <!-- probe 78 40 #00000000 -->

docs/roadmap.md

@@ -1,6 +1,6 @@
 # FigCraft roadmap: milestones and what's next
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-30 · **Change:** minor (the Pages, Layers and Assets search fields keep their text in the middle of the field (#1703); a board connector's path can be reshaped by dragging its path handles (#1710); boards have 16 more shapes (arrows, polygons, star, plus and flowchart symbols), in pickers that lay them out in a grid; library analytics count insertions and show insertions and detachments over the past 30 days, 90 days or year; a stroke's Custom style takes a dash pattern of any length as a comma-separated list (#1681); a control request can set its own timeout, up to 10 minutes (`timeoutMs`; `figcraft-cli mcp --attach PORT --timeout SECONDS`) (#1696); gap 6: a widget opens its plugin's panel (plugin API 5), whose callbacks redraw it; the keyboard's Menu key opens the context menu, as Shift+F10 does; an Open link action can open in place of the prototype, with "Open in new tab" off (gap 15); a collection of this file can be extended (Extend collection on its row, `variable.extendCollection`), its extension following its edits at once, and extended collections extend again in the file; the eyedropper with Cmd/Ctrl+Shift makes a colour style or variable of what it picks; a live session's welcome sends the document compressed to clients that read it, about seven times smaller (#1665); a control request that times out says truthfully whether it was dropped or is still running and will take effect, and only screenshots and input blame the window (#1673); a board keeps earlier votes' results, listed newest first in Results and deleted one at a time; a server can list the files shared from it now for everyone who reaches it, Home ▸ Online shows them and their links carry no secret (`team_files`, part of #742); a selected connector's bar on a board sets its start and end points, solid or dashed, its weight and any colour (#1596); cells copied from a spreadsheet paste onto a board as a table; a long layer name stays on one line in the Export button and the Dev Mode header, ending with an ellipsis, and no longer covers the Design panel (#1650); with hundreds of layers selected, the Design panel and the selection overlays stop going over the whole selection on every frame, so dragging 648 layers averages about 1.1 ms of UI per frame (#1571); plugin panels show pictures: an `image` control, base64 within 256 KB and 4,096 px a side, named by its label (gap 6); a drag moving many layers re-runs only what sits around them, not each layer's bindings, sizing, text and instance checks, on every move (#1571); damaged font tracking table offsets are checked instead of wrapping on 32-bit targets, and font indexing makes its existing offset bounds explicit (#1125); pasted layers whose image the clipboard lacks are named and show a placeholder that reads as missing (#1646); paint-style colours on layers pasted from another design app keep their style instead of turning black (#1638); Shift+Cmd/Ctrl+Enter on a selected board shape adds the next shape already joined to it, and goes on typing (#1597); a name typed for a variable or collection finds the one with that exact id before one named like it, and stored mode ids, font family variables and the panels' labels read exact ids (#1613); plugin widgets have hover styles: a layer's `hover` fill, stroke, opacity or text colour shows while the pointer is over it (gap 6); every file a command reads whole by path is a regular file within a cap that fits it: documents 16 GiB, placed images 256 MiB, CLI scripts 1 GiB; compact layer trees with fields and outline (M0.9, part of #996); while a drag only moves a large selection, its outlines, box, slots, spacing and Design panel values are worked out once and shifted, not rebuilt on every move (#1571); an imported or pasted file finds an installed family under the other names its fonts give it, and with other case and spacing, instead of reporting it missing (#1292); a panic in a grouped closure outside any command rolls the group back like a failed group: documents, selection, undo and redo, history limit and journal as before (#1085); a development example generates figcraft-cli's shell completions and man pages from its clap definitions (part of #1396); `.fig` ZIP image reads share a total byte budget and count skipped images in the import warnings (#1076); stored variable and collection references keep their identity when another object is named like their id (follow-up to #1542); a component set's property rows fit the 240 px right panel: variant values wrap two to a line there and every + and − stays in view; the server key is checked by comparing SHA-256 hashes of the presented and the kept key, as the deployment guide says (#1130); opening a file contacts no team library server it names until you check it (#1097); a hostile server can no longer grow a client's memory with made-up people, and a session remembers a bounded number of deleted layer ids (#1121); `doc.list` giLine truncated
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-30 · **Change:** minor (a dashed line starts and ends with a half-length dash, on the canvas and in exports; the Pages, Layers and Assets search fields keep their text in the middle of the field (#1703); a board connector's path can be reshaped by dragging its path handles (#1710); boards have 16 more shapes (arrows, polygons, star, plus and flowchart symbols), in pickers that lay them out in a grid; library analytics count insertions and show insertions and detachments over the past 30 days, 90 days or year; a stroke's Custom style takes a dash pattern of any length as a comma-separated list (#1681); a control request can set its own timeout, up to 10 minutes (`timeoutMs`; `figcraft-cli mcp --attach PORT --timeout SECONDS`) (#1696); gap 6: a widget opens its plugin's panel (plugin API 5), whose callbacks redraw it; the keyboard's Menu key opens the context menu, as Shift+F10 does; an Open link action can open in place of the prototype, with "Open in new tab" off (gap 15); a collection of this file can be extended (Extend collection on its row, `variable.extendCollection`), its extension following its edits at once, and extended collections extend again in the file; the eyedropper with Cmd/Ctrl+Shift makes a colour style or variable of what it picks; a live session's welcome sends the document compressed to clients that read it, about seven times smaller (#1665); a control request that times out says truthfully whether it was dropped or is still running and will take effect, and only screenshots and input blame the window (#1673); a board keeps earlier votes' results, listed newest first in Results and deleted one at a time; a server can list the files shared from it now for everyone who reaches it, Home ▸ Online shows them and their links carry no secret (`team_files`, part of #742); a selected connector's bar on a board sets its start and end points, solid or dashed, its weight and any colour (#1596); cells copied from a spreadsheet paste onto a board as a table; a long layer name stays on one line in the Export button and the Dev Mode header, ending with an ellipsis, and no longer covers the Design panel (#1650); with hundreds of layers selected, the Design panel and the selection overlays stop going over the whole selection on every frame, so dragging 648 layers averages about 1.1 ms of UI per frame (#1571); plugin panels show pictures: an `image` control, base64 within 256 KB and 4,096 px a side, named by its label (gap 6); a drag moving many layers re-runs only what sits around them, not each layer's bindings, sizing, text and instance checks, on every move (#1571); damaged font tracking table offsets are checked instead of wrapping on 32-bit targets, and font indexing makes its existing offset bounds explicit (#1125); pasted layers whose image the clipboard lacks are named and show a placeholder that reads as missing (#1646); paint-style colours on layers pasted from another design app keep their style instead of turning black (#1638); Shift+Cmd/Ctrl+Enter on a selected board shape adds the next shape already joined to it, and goes on typing (#1597); a name typed for a variable or collection finds the one with that exact id before one named like it, and stored mode ids, font family variables and the panels' labels read exact ids (#1613); plugin widgets have hover styles: a layer's `hover` fill, stroke, opacity or text colour shows while the pointer is over it (gap 6); every file a command reads whole by path is a regular file within a cap that fits it: documents 16 GiB, placed images 256 MiB, CLI scripts 1 GiB; compact layer trees with fields and outline (M0.9, part of #996); while a drag only moves a large selection, its outlines, box, slots, spacing and Design panel values are worked out once and shifted, not rebuilt on every move (#1571); an imported or pasted file finds an installed family under the other names its fonts give it, and with other case and spacing, instead of reporting it missing (#1292); a panic in a grouped closure outside any command rolls the group back like a failed group: documents, selection, undo and redo, history limit and journal as before (#1085); a development example generates figcraft-cli's shell completions and man pages from its clap definitions (part of #1396); `.fig` ZIP image reads share a total byte budget and count skipped images in the import warnings (#1076); stored variable and collection references keep their identity when another object is named like their id (follow-up to #1542); a component set's property rows fit the 240 px right panel: variant values wrap two to a line there and every + and − stays in view; the server key is checked by comparing SHA-256 hashes of the presented and the kept key, as the deployment guide says (#1130); opening a file contacts no team library server it names until you check it (#1097); a hostile server can no longer grow a client's memory with made-up people,Line truncated
 
 Forward-looking plan. Where FigCraft stands today: [`ROADMAP.md`](../ROADMAP.md) and
 [`target-app-parity.md`](target-app-parity.md); the full ranked list: [`gaps.md`](gaps.md). Hours
@@ -75,6 +75,7 @@ blockers.
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-31 | patch | M4: an open dashed line starts and ends with a half-length dash, with a whole number of patterns fitted to it (dashes and gaps scaled together), for Dash and Custom patterns, on the canvas, in PNG, PDF and SVG (`stroke-dashoffset`) and in Outline stroke. Closed paths are unchanged. An imported SVG's open dashed line follows the same rule. |
 | 2026-10-31 | patch | M8, #1703: the search fields in the Pages, Layers and Assets panels keep their text in the middle of the field. It hung 5 points low in Pages and Layers and 2 in Assets, in every file: the editor was laid out in a box one line tall, shorter than the theme's least height for an editor. All three now share `widgets::search_box`, on the editor the other text fields use. |
 | 2026-10-31 | minor | M12, #1710: a selected elbow or curved connector shows path handles. Dragging a run moves it and a first or last run gains an extra run to stay on its end; a curve's middle goes where it is dragged (`board.reshape`, one undo step). The shape travels with what the connector joins, is saved with the file, and goes back to routing itself when the style changes or an end moves to something else. |
 | 2026-10-31 | minor | M12: boards have 23 shapes with text instead of 7: triangle down, parallelogram right and left, trapezoid, pentagon, hexagon, octagon, star, plus, arrow left and right, and the flowchart symbols database, document, predefined process, manual input and internal storage. The toolbar flyout wraps into rows of eight and the selection bar's shape menu is a grid of outlines named on hover. The stale "Quick-create handles: missing" row now says what exists. |