PDF/EPS export: live art expanded for pattern tile images counts against the object limit

Blends, envelopes, repeats and Intertwine groups that hold a pattern fill
with a transparent tile image were each expanded under a limit of their
own, so many of them together had no limit. Their art now counts toward
the same limit as the pattern tiles, and an object whose art would pass
it stays live.

crates/engine/src/cmd/expand.rs

@@ -453,9 +453,9 @@ fn expand_pattern_fills(s: &mut Session) -> Result<()> {
 /// first ([`expand_live_with_transparent_image_patterns`]). Hidden shapes and shapes in hidden
 /// groups or layers and in template layers stay as they are. A pattern fill in tile art counts
 /// too, down to the [`PATTERN_LEVELS`] the canvas draws, and the tile art the expansion makes is
-/// expanded again for it. A pattern fill stays when its tiles would take the expanded art past
-/// [`MAX_GENERATED`](vectorcraft_doc::live::MAX_GENERATED) objects. Returns how many objects
-/// changed.
+/// expanded again for it. A pattern fill stays, and a live object stays live, when its art would
+/// take the expanded art past [`MAX_GENERATED`](vectorcraft_doc::live::MAX_GENERATED) objects.
+/// Returns how many objects changed.
 pub(crate) fn expand_transparent_image_patterns(
     d: &mut Document,
     root: NodeId,
@@ -465,8 +465,7 @@ pub(crate) fn expand_transparent_image_patterns(
     expand_transparent_image_patterns_within(d, root, see_through, colorize, vectorcraft_doc::live::MAX_GENERATED)
 }
 
-/// [`expand_transparent_image_patterns`] with the art the pattern fills expand to held to `budget`
-/// objects. Live art expands under its own budget ([`expand_live_with_transparent_image_patterns`]).
+/// [`expand_transparent_image_patterns`] with the expanded art held to `budget` objects.
 pub(crate) fn expand_transparent_image_patterns_within(
     d: &mut Document,
     root: NodeId,
@@ -478,7 +477,7 @@ pub(crate) fn expand_transparent_image_patterns_within(
     let made = std::cell::Cell::new(0usize);
     // Each pass brings the patterns in the expanded tiles' art up one level.
     for levels in (1..=PATTERN_LEVELS).rev() {
-        let live = expand_live_with_transparent_image_patterns(d, root, see_through, colorize, levels)?;
+        let live = expand_live_with_transparent_image_patterns(d, root, see_through, colorize, levels, &made, budget)?;
         let (_, n) = replace_leaves(d, root, |d, l| {
             // Past the budget, and for most leaves, which have no pattern fill, skip the ancestry walk.
             if made.get() >= budget || !l.appearance.items.iter().any(|i| pattern_fill(d, i).is_some()) {
@@ -547,13 +546,17 @@ fn drawn(n: &Node) -> bool {
 /// Expand the shown blends, envelopes, repeats and Intertwine groups under `root` that hold a
 /// pattern fill [`holds_transparent_image_patterns`] counts with `levels` into the art the exporters write for
 /// them ([`expand_live_deep`](vectorcraft_render::effects::expand_live_deep), under one budget for
-/// everything nested in each), so the shapes they draw are leaves. Returns how many were expanded.
+/// everything nested in each), so the shapes they draw are leaves. The objects that art holds count
+/// in `made`, and an object whose art would take `made` past `budget` stays live. Returns how many
+/// were expanded.
 fn expand_live_with_transparent_image_patterns(
     d: &mut Document,
     root: NodeId,
     see_through: &BTreeSet<String>,
     colorize: &dyn Fn(&Document, &Node) -> bool,
     levels: u32,
+    made: &std::cell::Cell<usize>,
+    budget: usize,
 ) -> Result<usize> {
     fn outermost(
         d: &Document,
@@ -592,10 +595,19 @@ fn expand_live_with_transparent_image_patterns(
     }
     let mut count = 0;
     for id in &live {
+        if made.get() >= budget {
+            break;
+        }
         let Some(n) = d.node(*id) else { continue };
         // Random Transform effects take their seed from the ids: bake them first ([`bake_seeded`]),
         // and leave the object live when that can't be done.
         let Some(mut g) = bake_seeded(&vectorcraft_render::effects::expand_live_deep(Some(d), n)) else { continue };
+        // An object whose art would take the expanded art past the budget stays live.
+        let size = g.count_with_masks();
+        if size > budget - made.get() {
+            continue;
+        }
+        made.set(made.get() + size);
         g.id = *id;
         fresh_ids(d, &mut g);
         *d.node_mut(*id).ok_or(EngineError::NoNode(*id))? = g;

crates/engine/src/tests/legacy_ai.rs

@@ -919,6 +919,22 @@ fn pdf13_flattens_colorized_pattern_tile_images_in_a_repeat() {
     assert_pdf13_draws_pattern_square_as_canvas(&mut s);
 }
 
+/// A repeat whose art would take the expanded art past the budget stays live.
+#[test]
+fn a_repeat_past_the_budget_stays_live() {
+    for (budget, live) in [(1, 1), (usize::MAX, 0)] {
+        let mut s = colorized_pattern_over_blue();
+        let square = pattern_square(&s);
+        s.execute("object.repeat.grid", &json!({"ids": [square.0]})).unwrap();
+        let d = std::sync::Arc::make_mut(&mut s.doc_mut().unwrap().doc);
+        let layer = d.layers[0].id;
+        crate::cmd::expand::expand_transparent_image_patterns_within(d, layer, &Default::default(), &|_, _| true, budget).unwrap();
+        let mut repeats = 0;
+        d.walk(|n| repeats += usize::from(matches!(n.kind, vectorcraft_doc::NodeKind::Repeat(_))));
+        assert_eq!(repeats, live, "budget {budget}");
+    }
+}
+
 /// [`colorized_pattern_over_blue`] with the square filled with a pattern named `outer` whose tile
 /// art is a 32 pt square filled with the colorized image pattern.
 fn nested_colorized_pattern_over_blue() -> Session {