layout: leave out a grid that would pass the snap budget

crates/layout/src/depth_tests.rs

@@ -102,6 +102,6 @@ fn snap_lines_are_bounded_across_a_frames_grids() {
     let f = d.create(p, NodeKind::Frame, "F", 0.0, 0.0, 4000.0, 4000.0).unwrap();
     d.get_mut(f).unwrap().grids = vec![LayoutGrid { kind: GridKind::Grid, size: 1.0, visible: true, ..LayoutGrid::default() }; 1000];
     let (xs, ys) = crate::grid_snap_lines(&d, f);
-    assert!(xs.len() + ys.len() < 250_000, "{}", xs.len() + ys.len());
+    assert!(xs.len() + ys.len() <= 200_000, "{}", xs.len() + ys.len());
     assert!(xs.len() > 4000 && ys.len() > 4000, "the first grids still give their lines");
 }

crates/layout/src/lib.rs

@@ -1169,11 +1169,13 @@ pub fn grid_snap_lines_in(doc: &Document, frame: NodeId, xf: Affine) -> (Vec<f64
     let mut xs = Vec::new();
     let mut ys = Vec::new();
     for g in f.grids.iter().filter(|g| g.visible) {
-        // A frame-wide budget: each grid adds up to ~17,000 lines, and a file can hold any number of grids.
-        if xs.len() + ys.len() >= MAX_SNAP_LINES {
+        // A frame-wide budget: each grid adds up to ~17,000 lines, and a file can hold any number of grids;
+        // a grid that would pass it is left out whole.
+        let lines = grid_lines(g, f.width, f.height);
+        if xs.len() + ys.len() + 2 * lines.len() > MAX_SNAP_LINES {
             break;
         }
-        for r in grid_lines(g, f.width, f.height) {
+        for r in lines {
             let a = xf * Point::new(r.x0, r.y0);
             let b = xf * Point::new(r.x1, r.y1);
             match g.kind {