PDF/EPS export: pattern fills whose tiles pass the object limit stay pattern fills

The expansion counted the objects a pattern fill made only after making
them, so one shape could clone up to 250,000 tile positions times the
tile art's objects past the limit. Each fill now counts its tiles before
they are made, and after outlining strokes and effects for turned or
sheared tiles, and keeps room for the copy and group of the fills after
it. A fill that does not fit stays a pattern fill.

crates/engine/src/tests/legacy_ai.rs

@@ -705,6 +705,61 @@ fn only_the_transparent_pattern_fill_of_a_leaf_is_expanded() {
     assert!(images > 0);
 }
 
+/// A pattern fill whose expanded art would hold more objects than the budget stays a pattern fill:
+/// the 32 pt tiles over the 128 pt square are 25 copies of the tile art's 3 objects, which are not
+/// made with a smaller budget, and the clip group around them counts too.
+#[test]
+fn a_transparent_image_pattern_past_the_budget_stays() {
+    let expand = |budget: usize| {
+        let mut s = pattern_over_blue(&checker([0, 200, 0, 255], [255, 255, 255, 0]), 1.0);
+        assert_eq!(s.doc().unwrap().doc.patterns[0].art.iter().map(|a| a.count_with_masks()).sum::<usize>(), 3);
+        let d = std::sync::Arc::make_mut(&mut s.doc_mut().unwrap().doc);
+        let keys = crate::cmd::flatten::see_through_images(d);
+        let layer = d.layers[0].id;
+        let before = d.layers[0].count_with_masks();
+        let n = crate::cmd::expand::expand_transparent_image_patterns_within(d, layer, &keys, &|_, _| true, budget).unwrap();
+        // The objects the expansion made, with the square it replaced.
+        (n, images(d).0, d.layers[0].count_with_masks() + 1 - before)
+    };
+    let (n, tiles, made) = expand(usize::MAX);
+    assert_eq!((n, tiles), (1, 25));
+    assert!(made > 75, "{made}");
+    assert_eq!(expand(made), (1, 25, made));
+    assert_eq!(expand(made - 1).0, 0);
+    assert_eq!(expand(74).0, 0);
+}
+
+/// On a shape with two transparent image pattern fills, both expand with a budget their tiles and
+/// the group around them fit, and one expands with one object less.
+#[test]
+fn two_transparent_image_pattern_fills_expand_within_the_budget() {
+    let expand = |budget: usize| {
+        let mut s = pattern_over_blue(&checker([0, 200, 0, 255], [255, 255, 255, 0]), 1.0);
+        let d = std::sync::Arc::make_mut(&mut s.doc_mut().unwrap().doc);
+        let mut square = None;
+        d.walk(|n| {
+            if n.appearance.items.iter().any(
+                |i| matches!(i, vectorcraft_doc::appearance::AppearanceItem::Fill(f) if matches!(f.paint, vectorcraft_color::Paint::Pattern { .. })),
+            ) {
+                square = Some(n.id);
+            }
+        });
+        let n = d.node_mut(square.unwrap()).unwrap();
+        assert_eq!(n.appearance.items.len(), 1);
+        let fill = n.appearance.items[0].clone();
+        n.appearance.items.push(fill);
+        let keys = crate::cmd::flatten::see_through_images(d);
+        let layer = d.layers[0].id;
+        let before = d.layers[0].count_with_masks();
+        let n = crate::cmd::expand::expand_transparent_image_patterns_within(d, layer, &keys, &|_, _| true, budget).unwrap();
+        (n, images(d).0, d.layers[0].count_with_masks() + 1 - before)
+    };
+    let (n, tiles, made) = expand(usize::MAX);
+    assert_eq!((n, tiles), (1, 50));
+    assert_eq!(expand(made), (1, 50, made));
+    assert_eq!(expand(made - 1).1, 25);
+}
+
 #[test]
 fn pdf13_flattens_see_through_pattern_tile_images() {
     let mut s = pattern_over_blue(&checker([0, 200, 0, 255], [255, 255, 255, 0]), 1.0);