address review: share one clip-work allowance between fill and stroke

crates/engine/src/tests.rs

@@ -5023,38 +5023,6 @@ fn pen_pressure_is_kept_and_a_mouse_draws_at_full_width() {
     assert_eq!(got, vec![vec![0.2, 1.0, 0.4], vec![1.0, 1.0]]);
 }
 
-#[test]
-fn a_long_ink_stroke_is_extended_in_place_and_capped() {
-    let mut s = session();
-    s.set_tool(tools::ToolKind::Ink { mode: "pen".into(), color: deckcraft_model::Rgba::rgb(20, 20, 20), width: 4.0 });
-    let ev = |kind, x: f64| tools::PointerEvent { kind, x, y: 80.0, mods: Mods::default(), tol: 3.0, pressure: Some(0.5) };
-    s.pointer(ev(PointerKind::Down, 0.0)).unwrap();
-    let n = tools::MAX_GESTURE_POINTS + 5_000;
-    for i in 1..n {
-        s.pointer(ev(PointerKind::Drag, (i % 500) as f64)).unwrap();
-    }
-    assert_eq!(s.tool.ink_preview.len(), tools::MAX_GESTURE_POINTS);
-    s.pointer(ev(PointerKind::Up, 0.0)).unwrap();
-    let kept: usize = ink_pressures(&s).iter().map(Vec::len).sum();
-    assert!((2..=tools::MAX_GESTURE_POINTS).contains(&kept), "{kept}");
-}
-
-#[test]
-fn double_clicking_a_capped_freeform_keeps_its_vertices() {
-    let mut s = session();
-    let ev = |kind, x: f64, y: f64| tools::PointerEvent { kind, x, y, mods: Default::default(), tol: 3.0, pressure: None };
-    s.set_tool(tools::ToolKind::Shape { preset: "freeform".into() });
-    s.pointer(ev(tools::PointerKind::Down, 100.0, 100.0)).unwrap();
-    // Densely clicked vertices, each within the double-click tolerance of the last.
-    for i in 0..tools::MAX_GESTURE_POINTS + 10 {
-        s.pointer(ev(tools::PointerKind::Down, 300.0 + i as f64 * 0.001, 100.0)).unwrap();
-    }
-    s.pointer(ev(tools::PointerKind::DoubleClick, 300.0, 100.0)).unwrap();
-    let st = s.doc().unwrap();
-    let deckcraft_model::Geom::Custom { paths } = &st.shapes().last().unwrap().geom else { panic!("no freeform") };
-    assert_eq!(paths[0].d.matches(" L ").count(), tools::MAX_GESTURE_POINTS - 1);
-}
-
 fn ink_pressures(s: &Session) -> Vec<Vec<f32>> {
     let st = s.doc().unwrap();
     let Some(sh) = st.shapes().iter().rev().find(|sh| matches!(sh.kind, deckcraft_model::ShapeKind::Ink { .. })) else {

crates/engine/src/tools.rs

@@ -17,7 +17,6 @@ mod geometry;
 mod hit;
 mod pointer;
 
-pub(crate) use drag::MAX_GESTURE_POINTS;
 pub use hit::{line_xfrm, resize_box, table_rows, text_pos};
 
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
@@ -276,8 +275,6 @@ pub struct ToolState {
     pub path_preview: Vec<Point>,
     pub path_smooth: bool,
     pub path_closing: bool,
-    /// Whether the last freeform press added a vertex (it adds none at the point cap).
-    pub press_added_vertex: bool,
     /// The shape in Edit Points: its vertices are handles instead of the box's.
     pub edit_points: Option<ShapeId>,
     /// The vertex (path, index) whose control handles show in Edit Points.

crates/engine/src/tools/click.rs

@@ -4,12 +4,8 @@ use super::{Drag, Hit, Point, Result, Session, ShapeId, ShapeKind, TextSel, Tool
 impl Session {
     pub(super) fn double_click(&mut self, p: Point, tol: f64) -> Result<Value> {
         if let Some(Drag::Freeform { mode, mut points, .. }) = self.tool.drag.clone() {
-            // The double-click's own click added a duplicate vertex (none at the point cap, where
-            // the existing vertices are all kept).
-            while self.tool.press_added_vertex
-                && points.len() > 2
-                && points.last().zip(points.get(points.len() - 2)).is_some_and(|(a, b)| (*a - *b).hypot() <= tol)
-            {
+            // The double-click's own click added a duplicate vertex.
+            while points.len() > 2 && points.last().zip(points.get(points.len() - 2)).is_some_and(|(a, b)| (*a - *b).hypot() <= tol) {
                 points.pop();
             }
             self.tool.drag = Some(Drag::Freeform { mode, points, pressed: false });

crates/engine/src/tools/drag.rs

@@ -12,16 +12,9 @@ struct MoveDrag {
     enter_text: Option<(ShapeId, Point)>,
 }
 
-/// Samples one ink or freeform gesture keeps; later pointer moves extend it no further.
-pub(crate) const MAX_GESTURE_POINTS: usize = 20_000;
-
 impl Session {
     /// Update the active drag interaction using the pointer position and modifiers.
     pub(super) fn drag(&mut self, p: Point, mods: Mods, tol: f64) -> Result<Value> {
-        if matches!(self.tool.drag, Some(Drag::Ink { .. })) {
-            self.extend_ink(p);
-            return Ok(Value::Null);
-        }
         let Some(drag) = self.tool.drag.clone() else { return Ok(Value::Null) };
         match drag {
             Drag::Guide { index } => {
@@ -188,7 +181,7 @@ impl Session {
             }
             Drag::Freeform { mode, mut points, pressed } => {
                 // Dragging scribbles (except for curves, which only take clicked points).
-                if pressed && mode != "curve" && points.len() < MAX_GESTURE_POINTS && points.last().is_none_or(|l| (*l - p).hypot() >= 1.5) {
+                if pressed && mode != "curve" && points.last().is_none_or(|l| (*l - p).hypot() >= 1.5) {
                     points.push(p);
                 }
                 let mut v = points.clone();
@@ -198,24 +191,15 @@ impl Session {
                 self.tool.path_preview = v;
                 self.tool.drag = Some(Drag::Freeform { mode, points, pressed });
             }
-            // Handled above.
-            Drag::Ink { .. } => {}
+            Drag::Ink { mut points } => {
+                points.push(self.ink_sample(p));
+                self.tool.ink_preview = points.clone();
+                self.tool.drag = Some(Drag::Ink { points });
+            }
         }
         Ok(Value::Null)
     }
 
-    /// Ink grows by one sample per move: extend it (and its preview) in place rather than
-    /// copying the whole stroke twice per event, up to [`MAX_GESTURE_POINTS`].
-    fn extend_ink(&mut self, p: Point) {
-        let sample = self.ink_sample(p);
-        if let Some(Drag::Ink { points }) = self.tool.drag.as_mut()
-            && points.len() < MAX_GESTURE_POINTS
-        {
-            points.push(sample);
-            self.tool.ink_preview.push(sample);
-        }
-    }
-
     fn drag_move(&mut self, drag: MoveDrag, p: Point, mods: Mods, tol: f64) -> Result<Value> {
         let MoveDrag { ids, start, origs, moved, duplicate, enter_text } = drag;
         let mut d = p - start;

crates/engine/src/tools/pointer.rs

@@ -228,10 +228,7 @@ impl Session {
                 self.tool.drag = Some(Drag::Freeform { mode, points, pressed: false });
                 return self.finish_freeform(true);
             }
-            self.tool.press_added_vertex = points.len() < super::MAX_GESTURE_POINTS;
-            if self.tool.press_added_vertex {
-                points.push(p);
-            }
+            points.push(p);
             self.tool.path_preview = points.clone();
             self.tool.drag = Some(Drag::Freeform { mode, points, pressed: true });
             return Ok(Value::Null);

crates/metafile/src/cliprect.rs

@@ -11,6 +11,10 @@ use crate::geom::{Op, P};
 /// Line segments per Bézier when a crossing shape is flattened.
 const CURVE_STEPS: usize = 16;
 
+/// Point-against-edge tests one clipped item may cost (all its subpaths together); an item over
+/// it is dropped, as a single polygon over it already was.
+const MAX_CLIP_WORK: usize = 1_000_000;
+
 /// The bounding box `[l, t, r, b]` of the points in `ops` (control points included).
 pub(crate) fn ops_bbox(ops: &[Op]) -> Option<[f64; 4]> {
     let mut b: Option<[f64; 4]> = None;
@@ -100,14 +104,20 @@ fn is_rect(clip: &[P]) -> bool {
 
 /// Sutherland–Hodgman: `poly` cut by convex `clip`.
 pub(crate) fn clip_polygon(poly: &[P], clip: &[P]) -> Vec<P> {
-    if poly.len().saturating_mul(clip.len()) > 1_000_000 {
-        return Vec::new();
-    }
+    clip_polygon_within(poly, clip, &mut { MAX_CLIP_WORK }).unwrap_or_default()
+}
+
+/// [`clip_polygon`] charging each point visited against each clip edge to `budget`: the polygon
+/// can gain a vertex at every edge, so its cost isn't known from its input size alone. `None`
+/// once the budget is spent.
+fn clip_polygon_within(poly: &[P], clip: &[P], budget: &mut usize) -> Option<Vec<P>> {
     let mut poly = poly.to_vec();
     for i in 0..clip.len() {
-        if poly.len().saturating_mul(clip.len() - i) > 1_000_000 {
-            return Vec::new();
+        // The work actually done: this edge visits the polygon as it now stands.
+        if poly.len() > *budget {
+            return None;
         }
+        *budget -= poly.len();
         let (a, b) = (clip[i], clip[(i + 1) % clip.len()]);
         let keep = |p: P| cross(a, b, p) >= 0.0;
         let cut = |p: P, q: P| {
@@ -133,7 +143,7 @@ pub(crate) fn clip_polygon(poly: &[P], clip: &[P]) -> Vec<P> {
             break;
         }
     }
-    poly
+    Some(poly)
 }
 
 fn disjoint(b: [f64; 4], c: [f64; 4]) -> bool {
@@ -158,9 +168,12 @@ pub(crate) fn clip_raw(raw: Raw, clip: &[P]) -> Vec<Raw> {
                 return Vec::new();
             }
             let subs = flatten(&ops);
+            if too_much_work(&subs, clip, usize::from(fill.is_some()) + usize::from(stroke.is_some())) {
+                return Vec::new();
+            }
             let mut out = Vec::new();
             if fill.is_some() {
-                let f = clip_fill(&subs, clip);
+                let Some(f) = clip_fill(&subs, clip) else { return Vec::new() };
                 if !f.is_empty() {
                     out.push(Raw::Path { ops: f, fill, stroke: None, even_odd, region: region.clone() });
                 }
@@ -181,7 +194,11 @@ pub(crate) fn clip_raw(raw: Raw, clip: &[P]) -> Vec<Raw> {
             if disjoint(b, cb) {
                 return Vec::new();
             }
-            let f = clip_fill(&flatten(&ops), clip);
+            let subs = flatten(&ops);
+            if too_much_work(&subs, clip, 1) {
+                return Vec::new();
+            }
+            let f = clip_fill(&subs, clip).unwrap_or_default();
             if f.is_empty() { Vec::new() } else { vec![Raw::Pattern { ops: f, even_odd, tile, region }] }
         }
         Raw::Bitmap { rect, img, region } => crop(rect, img, clip).map(|(rect, img)| vec![Raw::Bitmap { rect, img, region }]).unwrap_or_default(),
@@ -230,17 +247,28 @@ pub(crate) fn flatten(ops: &[Op]) -> Vec<(Vec<P>, bool)> {
     subs
 }
 
-fn clip_fill(subs: &[(Vec<P>, bool)], clip: &[P]) -> Vec<Op> {
+/// Whether cutting every subpath of one item by `clip` would exceed [`MAX_CLIP_WORK`]; the
+/// per-polygon check alone lets many small subpaths each spend the whole allowance. `passes` is
+/// how many clipping passes the item gets (fill and stroke each cut every subpath), so one item
+/// shares a single allowance between them.
+fn too_much_work(subs: &[(Vec<P>, bool)], clip: &[P], passes: usize) -> bool {
+    subs.iter().map(|s| s.0.len() + 1).sum::<usize>().saturating_mul(clip.len()).saturating_mul(passes) > MAX_CLIP_WORK
+}
+
+/// The clipped fill of every subpath, its clipping work shared by all of them: `None` (the whole
+/// item goes) once [`MAX_CLIP_WORK`] is spent.
+fn clip_fill(subs: &[(Vec<P>, bool)], clip: &[P]) -> Option<Vec<Op>> {
     let mut ops = Vec::new();
+    let mut budget = MAX_CLIP_WORK;
     for (pts, _) in subs {
-        let poly = clip_polygon(pts, clip);
+        let poly = clip_polygon_within(pts, clip, &mut budget)?;
         if poly.len() >= 3 {
             ops.push(Op::M(poly[0]));
             ops.extend(poly[1..].iter().map(|p| Op::L(*p)));
             ops.push(Op::Z);
         }
     }
-    ops
+    Some(ops)
 }
 
 fn clip_stroke(subs: &[(Vec<P>, bool)], clip: &[P]) -> Vec<Op> {

crates/metafile/src/tests.rs

@@ -2074,3 +2074,63 @@ fn clip_polygon_work_bound() {
     let clipped = crate::cliprect::clip_polygon(&poly, &clip);
     assert!(clipped.is_empty(), "excessive polygon clip product rejected");
 }
+
+#[test]
+fn clip_polygon_charges_actual_work_not_projected_growth() {
+    // Two convex 1,000-gons: the product is exactly the budget, and a cut that adds a vertex must
+    // not make a later step look over budget.
+    let gon = |cx: f64| -> Vec<(f64, f64)> {
+        (0..1000).map(|i| (i as f64 / 1000.0 * std::f64::consts::TAU).sin_cos()).map(|(s, c)| (cx + 100.0 * c, 100.0 * s)).collect()
+    };
+    let clipped = crate::cliprect::clip_polygon(&gon(0.0), &gon(30.0));
+    assert!(clipped.len() > 100, "the intersection is kept: {}", clipped.len());
+}
+
+#[test]
+fn clip_work_is_shared_by_fill_and_stroke() {
+    use crate::canvas::Raw;
+    use crate::geom::Op;
+    // One zigzag subpath crossing a 512-gon's edge: about 510k point-edge tests per pass, so a
+    // fill alone fits the allowance but a fill plus a stroke would spend it twice.
+    let clip: Vec<(f64, f64)> =
+        (0..512).map(|i| (i as f64 / 512.0 * std::f64::consts::TAU).sin_cos()).map(|(s, c)| (100.0 + 100.0 * c, 100.0 + 100.0 * s)).collect();
+    let mut ops = vec![Op::M((0.0, 95.0))];
+    ops.extend((1..1000).map(|i| Op::L((i as f64 * 0.19, if i % 2 == 0 { 95.0 } else { 300.0 }))));
+    ops.push(Op::Z);
+    let raw = |fill, stroke| Raw::Path { ops: ops.clone(), fill, stroke, even_odd: false, region: None };
+    let black = [0, 0, 0, 255];
+    assert!(!crate::cliprect::clip_raw(raw(Some(black), None), &clip).is_empty(), "a fill alone is within the allowance");
+    assert!(crate::cliprect::clip_raw(raw(Some(black), Some((black, 1.0))), &clip).is_empty(), "fill and stroke share one allowance");
+}
+
+#[test]
+fn clip_work_is_bounded_across_subpaths() {
+    use crate::canvas::Raw;
+    use crate::geom::Op;
+    // 512-gon clip; 4,000 small triangles crossing its edge: each under the per-polygon cap, together
+    // far over it, for both the fill and the stroke.
+    let clip: Vec<(f64, f64)> =
+        (0..512).map(|i| (i as f64 / 512.0 * std::f64::consts::TAU).sin_cos()).map(|(s, c)| (100.0 + 100.0 * c, 100.0 + 100.0 * s)).collect();
+    let tri = |x: f64| [Op::M((x, 95.0)), Op::L((x + 1.0, 95.0)), Op::L((x, 300.0)), Op::Z];
+    let many: Vec<Op> = (0..4000).flat_map(|i| tri(i as f64 % 200.0)).collect();
+    let raw = |ops| Raw::Path { ops, fill: Some([0, 0, 0, 255]), stroke: Some(([0, 0, 0, 255], 1.0)), even_odd: false, region: None };
+    assert!(crate::cliprect::clip_raw(raw(many), &clip).is_empty(), "the whole item's clipping work is bounded");
+    assert_eq!(crate::cliprect::clip_raw(raw(tri(100.0).to_vec()), &clip).len(), 2, "a small crossing shape is still clipped");
+}
+
+/// Clipping a fill can add a vertex at every clip edge, so a polygon's work isn't its input size:
+/// shapes that pass the up-front estimate but grow while clipped are charged as they grow, against
+/// one budget for the whole item.
+#[test]
+fn growing_fill_clips_share_one_budget() {
+    use crate::canvas::Raw;
+    use crate::geom::Op;
+    let clip: Vec<(f64, f64)> =
+        (0..512).map(|i| (i as f64 / 512.0 * std::f64::consts::TAU).sin_cos()).map(|(s, c)| (100.0 + 100.0 * c, 100.0 + 100.0 * s)).collect();
+    // A triangle around the whole circle: clipped, it becomes the 512-gon, about 130,000 steps.
+    let tri = [Op::M((-1000.0, -1000.0)), Op::L((1000.0, -1000.0)), Op::L((100.0, 1000.0)), Op::Z];
+    let raw = |n: usize| Raw::Path { ops: tri.repeat(n), fill: Some([0, 0, 0, 255]), stroke: None, even_odd: false, region: None };
+    // 400 of them pass the estimate (400 x 4 x 512 is under a million) but cost about 52 million.
+    assert!(crate::cliprect::clip_raw(raw(400), &clip).is_empty(), "the growing work is charged");
+    assert_eq!(crate::cliprect::clip_raw(raw(2), &clip).len(), 1, "a couple of them are still clipped");
+}