Render: a shape far beyond any page is left undrawn, never crashing the app

A property test of the importers (import_fuzz) crashed CI with
STATUS_STACK_BUFFER_OVERRUN: a shape with coordinates in the 1e20s from a
mutated file made vello_cpu either panic in flatten_simd on a rayon
worker (rayon then aborts the process, so the engine's panic guard never
sees it) or ask for a 132 GB allocation, which aborts too. A malformed
file could end the app and lose the user's work.

draw_shape now leaves a shape undrawn when its control points, through
the view, aren't finite or reach past 1e10 pixels, or a visible stroke
is that wide (MAX_DEVICE). A document's art stays within 4 million
points, 2.6e9 pixels at the closest zoom, and vello was checked safe
with 90,000 random shapes within 1e9 pixels and 30,000 within 1e12.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

ROADMAP.md

@@ -127,7 +127,7 @@ Ranked; detail in [docs/roadmap.md](docs/roadmap.md) and [docs/gaps.md](docs/gap
 
 | Date | What landed |
 |---|---|
-| 2026-10-11 | Effect › Brush Strokes: Accented Edges, Angled Strokes, Crosshatch, Dark Strokes, Ink Outlines, Spatter, Sprayed Strokes, Sumi-e (G2). Command parameters from agents and files checked before anything changes (paint, place, cuts, dashes, crop, asset ids, anchors, paths, distort; #984–#999); command dialogs keep whole numbers whole, so Create Object Mosaic takes the tiles typed (#1000); stepper arrows take Shift (×10) and Ctrl/Cmd (÷10) like the arrow keys (#991). Exports and Rasterize supersample Art Optimized edges, so shapes meeting edge to edge leave no seam (#983). Character and paragraph styles take leading, kerning, mojikumi and the other attributes left out at their defaults (#1001). Drawing, typing and pasting with no layer shown and unlocked is refused instead of adding art to a hidden or locked layer (#1002). MCP `add_text` gives type on or in a path the colour asked for (#1003). MCP `screenshot` of a connected app renders the artboard asked for (#1004). `vectorcraft-cli run` ends quietly when its reader closes early (#1005). Select › All on Active Artboard selects on the artboard made active, not always the first (#1006). Reverse Gradient keeps off-centre midpoints, mirrored (#1007). A polar grid with no radial dividers draws none (#1008). Use Precise Cursors also covers the Pen's join pointer (#1009). SVGs with one absolute and one unitless root side import at their size, unstretched (#1010). DXF US survey inches, yards and miles open at their size and name (#1011). A file placed into a document with no other links follows its first change even while the app sits idle (#1031). PDF import keeps the style a font name says when the file doesn't embed the font (#1023). Shift selects ruler guides and art together, and Delete removes both (#1022). Open filled paths are hit by their fill on every side, the rotate cursor bows around the corner it is at, the flip icons match their flips, the Color Picker previews on the selection, and Properties › Transform reaches Scale Corners and Scale Strokes & Effects (#1036). Offset Path and the other booleans finish on outlines where the sweep used to loop until memory ran out (linesweeper 0.5, #1028). Floating panel groups stack into sets that move together, collapse to their tabs and dock as extra dock columns that scroll (#1020). Ruler guides live on layers: listed in the Layers panel, shown, hidden, locked, duplicated, merged and deleted with their layer, and moved between layers (#1021). A `.ai` whose editing data uses global process colours (`Xk`/`XK`) or pattern fills keeps its sublayers: the colours come in as global swatches at their tint, the patterns as pattern swatches (#1025). A `.ai` in PostScript form opens through its layers, read from the program itself, also when it names the prolog defining its operators without including it, as Rhino and other CAD apps write it (#1027). A fill or stroke chosen while the Type tool has characters selected colours just those characters (#1063). Scaled type shows its scaled font size, leading, baseline shift and horizontal scale in the Character panel, and a size typed there is the size you get (#1034). Character panel menu › Proportional Metrics sets Japanese and Chinese full-width glyphs on the font's proportional widths in horizontal type (#966). Align, Distribute, Move, Arrange, Lock, Hide, Ungroup and other Object commands that would change nothing no longer record an undo step or mark the document changed (#1060). Spot colours defined in Lab open with their Lab values from `.ai` and PDF files, instead of as wrong RGB colours or their CMYK equivalents (#1032). Build scripts leave a generated source they wouldn't change untouched, so the next build doesn't compile most of the workspace again where file times lose their sub-second part (#1051). A fill colour recolours the gradient mesh point last clicked with the Mesh tool or Direct Selection, and a Mesh tool click on a mesh's point selects that mesh (#1052). The All Tools drawer stays two tools wide instead of filling a wide window (#1054). Text Wrap's Make, Release and Options refuse a list of object ids with a malformed or unknown id instead of skipping it (#1055). A freeform gradient line with a malformed point index is refused instead of being shortened to the indices that are valid (#1056). The Corners dialog (`ui.corners`) refuses a malformed object id or a listed anchor that isn't a corner instead of editing the selection or the other corners (#1057). New View refuses a centre that isn't exactly [x, y] and a rotation that isn't a number, instead of trimming the one and saving the other as 0° (#1058). The command sweeps try junk scale, spacing and artboard values too, which they had skipped since before those bugs were fixed (#1059). EPS and PostScript `arc` and `arcn` with huge angles no longer hang the import, and an arc whose angles are whole turns apart is empty, as the PostScript reference defines it (#1062). Align and DisLine truncated
+| 2026-10-11 | Effect › Brush Strokes: Accented Edges, Angled Strokes, Crosshatch, Dark Strokes, Ink Outlines, Spatter, Sprayed Strokes, Sumi-e (G2). Command parameters from agents and files checked before anything changes (paint, place, cuts, dashes, crop, asset ids, anchors, paths, distort; #984–#999); command dialogs keep whole numbers whole, so Create Object Mosaic takes the tiles typed (#1000); stepper arrows take Shift (×10) and Ctrl/Cmd (÷10) like the arrow keys (#991). Exports and Rasterize supersample Art Optimized edges, so shapes meeting edge to edge leave no seam (#983). Character and paragraph styles take leading, kerning, mojikumi and the other attributes left out at their defaults (#1001). Drawing, typing and pasting with no layer shown and unlocked is refused instead of adding art to a hidden or locked layer (#1002). MCP `add_text` gives type on or in a path the colour asked for (#1003). MCP `screenshot` of a connected app renders the artboard asked for (#1004). `vectorcraft-cli run` ends quietly when its reader closes early (#1005). Select › All on Active Artboard selects on the artboard made active, not always the first (#1006). Reverse Gradient keeps off-centre midpoints, mirrored (#1007). A polar grid with no radial dividers draws none (#1008). Use Precise Cursors also covers the Pen's join pointer (#1009). SVGs with one absolute and one unitless root side import at their size, unstretched (#1010). DXF US survey inches, yards and miles open at their size and name (#1011). A file placed into a document with no other links follows its first change even while the app sits idle (#1031). PDF import keeps the style a font name says when the file doesn't embed the font (#1023). Shift selects ruler guides and art together, and Delete removes both (#1022). Open filled paths are hit by their fill on every side, the rotate cursor bows around the corner it is at, the flip icons match their flips, the Color Picker previews on the selection, and Properties › Transform reaches Scale Corners and Scale Strokes & Effects (#1036). Offset Path and the other booleans finish on outlines where the sweep used to loop until memory ran out (linesweeper 0.5, #1028). Floating panel groups stack into sets that move together, collapse to their tabs and dock as extra dock columns that scroll (#1020). Ruler guides live on layers: listed in the Layers panel, shown, hidden, locked, duplicated, merged and deleted with their layer, and moved between layers (#1021). A `.ai` whose editing data uses global process colours (`Xk`/`XK`) or pattern fills keeps its sublayers: the colours come in as global swatches at their tint, the patterns as pattern swatches (#1025). A `.ai` in PostScript form opens through its layers, read from the program itself, also when it names the prolog defining its operators without including it, as Rhino and other CAD apps write it (#1027). A fill or stroke chosen while the Type tool has characters selected colours just those characters (#1063). Scaled type shows its scaled font size, leading, baseline shift and horizontal scale in the Character panel, and a size typed there is the size you get (#1034). Character panel menu › Proportional Metrics sets Japanese and Chinese full-width glyphs on the font's proportional widths in horizontal type (#966). Align, Distribute, Move, Arrange, Lock, Hide, Ungroup and other Object commands that would change nothing no longer record an undo step or mark the document changed (#1060). Spot colours defined in Lab open with their Lab values from `.ai` and PDF files, instead of as wrong RGB colours or their CMYK equivalents (#1032). Build scripts leave a generated source they wouldn't change untouched, so the next build doesn't compile most of the workspace again where file times lose their sub-second part (#1051). A fill colour recolours the gradient mesh point last clicked with the Mesh tool or Direct Selection, and a Mesh tool click on a mesh's point selects that mesh (#1052). The All Tools drawer stays two tools wide instead of filling a wide window (#1054). Text Wrap's Make, Release and Options refuse a list of object ids with a malformed or unknown id instead of skipping it (#1055). A freeform gradient line with a malformed point index is refused instead of being shortened to the indices that are valid (#1056). The Corners dialog (`ui.corners`) refuses a malformed object id or a listed anchor that isn't a corner instead of editing the selection or the other corners (#1057). New View refuses a centre that isn't exactly [x, y] and a rotation that isn't a number, instead of trimming the one and saving the other as 0° (#1058). The command sweeps try junk scale, spacing and artboard values too, which they had skipped since before those bugs were fixed (#1059). EPS and PostScript `arc` and `arcn` with huge angles no longer hang the import, and an arc whose angles are whole turns apart is empty, as the PostScript reference defines it (#1062). Align and DisLine truncated
 | 2026-10-10 | Initial live Revolve (Effect › 3D and Materials, #846, #605), in its own `three-d` crate. Progress docs re-measured and restructured to the craftrules standard (this page, `docs/target-app-parity.md`, `gaps.md`, `ui-parity.md`, the format, hardware, localization, effects and type checklists). Same day: v0.8.0; Effect › Distort, Pixelate and Texture filters (13); German interface; Variables (data merge); Graph Type value axes and tick marks; restart when the first frame never reaches the screen (#964) |
 | 2026-10-09 | Radial Blur, Smart Blur, Unsharp Mask (gap 2 begins); 340 commits, the busiest day |
 | 2026-10-08 | v0.5.0–v0.7.0; community contributions: Pen and shape-tool modifiers, Layers, Artboards, Japanese composition, Hebrew/Arabic type, interface languages, saved selections |

crates/render/src/lib.rs

@@ -1186,6 +1186,9 @@ impl Renderer {
     }
 
     fn draw_shape(&mut self, ctx: &mut RenderContext, f: &Frame, n: &Node, bp: &BezPath, rule: FillRule) {
+        if !drawable(bp, f.view, n) {
+            return;
+        }
         if fx::has_fx(n) {
             return self.draw_shape_fx(ctx, f, n, bp, rule);
         }
@@ -1700,6 +1703,21 @@ fn mask_value(r: u8, g: u8, b: u8, a: u8, clip: bool, invert: bool) -> u8 {
     (l.clamp(0.0, 1.0) * 255.0 + 0.5) as u8
 }
 
+/// Most pixels from the origin that a shape handed to the rasterizer may reach, or a stroke be
+/// wide. A document's art stays within 4 million points, 2.6 billion pixels at the closest zoom.
+/// Geometry far beyond that (from a malformed file) makes vello_cpu panic on a worker thread or ask
+/// for more memory than there is, either of which ends the app: it is left undrawn.
+const MAX_DEVICE: f64 = 1e10;
+
+/// Can shape `bp` of `n` be drawn through `view`: its control points (finite) within
+/// [`MAX_DEVICE`] pixels, and its visible strokes no wider?
+fn drawable(bp: &BezPath, view: Affine, n: &Node) -> bool {
+    let b = view.transform_rect_bbox(bp.control_box());
+    let scale = view.determinant().abs().sqrt();
+    let widest = n.appearance.items.iter().filter_map(|i| if let AppearanceItem::Stroke(st) = i { Some(st.width) } else { None }).fold(0.0, f64::max);
+    [b.x0, b.y0, b.x1, b.y1].iter().all(|v| v.is_finite() && v.abs() <= MAX_DEVICE) && (widest * scale).is_finite() && widest * scale <= MAX_DEVICE
+}
+
 /// A render context on the calling thread. vello_cpu's `RenderContext::new` defaults to a
 /// multithreaded dispatcher, which panics on filter effects (glows, shadows, blur).
 pub(crate) fn single_threaded_context(w: u16, h: u16) -> RenderContext {

crates/render/tests/stroke_geometry.rs

@@ -181,3 +181,30 @@ fn a_head_past_the_end_counts_in_the_visual_bounds_and_is_never_culled() {
     let img = render_region(&d, Rect::new(83.0, 40.0, 100.0, 60.0), S);
     assert!(img.ink() > 0, "the head is drawn");
 }
+
+/// A shape far beyond any document's reach (from a malformed file) is left undrawn instead of
+/// making the rasterizer panic on a worker thread or ask for terabytes, which would end the app;
+/// the art next to it still draws.
+#[test]
+fn shapes_far_beyond_the_page_are_left_undrawn_without_crashing() {
+    let mut d = Document::new(100.0, 100.0);
+    let layer = d.layers[0].id;
+    let mut far = vectorcraft_geom::BezPath::new();
+    far.move_to((13607718712.4, 13.2));
+    far.curve_to((-0.03, 720.96), (-3.08e17, -8.36e20), (-3.35e20, -1.0));
+    far.close_path();
+    let black =
+        || Appearance { items: vec![AppearanceItem::Fill(vectorcraft_doc::FillLayer::new(Paint::solid(Color::BLACK)))], ..Default::default() };
+    for (path, app) in [
+        (vectorcraft_geom::PathData::from_bezpath(&far), black()),
+        (shapes::rectangle(Rect::new(10.0, 10.0, 30.0, 30.0)), black()),
+        (shapes::rectangle(Rect::new(50.0, 50.0, 60.0, 60.0)), stroked(1e30, |_| {})),
+    ] {
+        let id = d.alloc_id();
+        d.insert(Some(layer), usize::MAX, vectorcraft_doc::Node::path(id, path, app)).unwrap();
+    }
+    let img = Renderer::new().render_region(&d, Rect::new(0.0, 0.0, 100.0, 100.0), 1.0, true);
+    let px = |x: usize, y: usize| img.pixels.get((y * img.width as usize + x) * 4).copied().unwrap();
+    assert_eq!(px(20, 20), 0, "the rectangle next to them draws");
+    assert_eq!(px(90, 5), 255, "nothing of the far shape or the huge stroke");
+}