pptx: index media, layouts, sections and table styles on export

The shaper lets one call grow to 256 glyphs per input character, as an
embedded font's substitutions decide, and every glyph was then copied out.
Items longer than 1 KiB are now shaped in pieces (cut at a space where one
is near, never before a combining mark or after a joiner), each with the
rest of the paragraph as context and the item's script, and a piece that
expands past 32 glyphs per character falls back to one glyph per character
from the cmap.

crates/anim/src/morph.rs

@@ -1,5 +1,7 @@
 //! Morph: matching shapes between two slides, interpolating their boxes and building the frames.
 
+use std::collections::{HashMap, HashSet, VecDeque};
+
 use deckcraft_model::resolve::{self, Ctx};
 use deckcraft_model::{ColorRef, Fill, Geom, Presentation, Rgba, Shape, ShapeId, ShapeKind, Slide, Xfrm, walk};
 
@@ -15,48 +17,66 @@ fn text_of(s: &Shape) -> String {
 /// kind and preset geometry if neither carries text. A text box with neither a name nor its text on
 /// the other slide stays unpaired and fades in place, as in PowerPoint (#119). Each shape is used
 /// once; top-level shapes only (groups move whole).
+///
+/// Each pass compares a key of the two shapes, so the shapes of `b` are indexed by key once per
+/// pass: matching costs the sum of the two shape lists, not their product.
 pub fn morph_pairs(a: &Slide, b: &Slide) -> Vec<(ShapeId, ShapeId)> {
     let mut pairs: Vec<(ShapeId, ShapeId)> = Vec::new();
     let mut used_a = vec![false; a.shapes.len()];
     let mut used_b = vec![false; b.shapes.len()];
-    let passes: [&dyn Fn(&Shape, &Shape) -> bool; 4] = [
-        &|x, y| x.name.starts_with("!!") && x.name == y.name,
-        &|x, y| !x.name.is_empty() && x.name == y.name,
-        &|x, y| {
-            if x.kind_name() != y.kind_name() {
-                return false;
+    // Each shape's text, worked out once rather than inside every comparison.
+    let text_a: Vec<String> = a.shapes.iter().map(text_of).collect();
+    let text_b: Vec<String> = b.shapes.iter().map(text_of).collect();
+    let forced = |s: &Shape, _: &str| (s.name.starts_with("!!")).then(|| MorphKey::Name(s.name.clone()));
+    let named = |s: &Shape, _: &str| (!s.name.is_empty()).then(|| MorphKey::Name(s.name.clone()));
+    let same_text = |s: &Shape, t: &str| (!t.trim().is_empty()).then(|| MorphKey::Text(s.kind_name(), t.to_string()));
+    let same_geom = |s: &Shape, t: &str| match s.geom.preset_name() {
+        Some(g) if t.trim().is_empty() => Some(MorphKey::Geom(s.kind_name(), g.to_string())),
+        _ => None,
+    };
+    let passes: [&dyn Fn(&Shape, &str) -> Option<MorphKey>; 4] = [&forced, &named, &same_text, &same_geom];
+    for key in passes {
+        // Unused shapes of `b` by key, in slide order: the front of each queue is the first unused
+        // match, which is the one a search through `b` would find.
+        let mut index: HashMap<MorphKey, VecDeque<usize>> = HashMap::new();
+        for (j, sb) in b.shapes.iter().enumerate() {
+            if used_b.get(j).copied().unwrap_or(true) {
+                continue;
             }
-            let tx = text_of(x);
-            !tx.trim().is_empty() && tx == text_of(y)
-        },
-        &|x, y| {
-            x.kind_name() == y.kind_name()
-                && x.geom.preset_name().is_some()
-                && x.geom.preset_name() == y.geom.preset_name()
-                && text_of(x).trim().is_empty()
-                && text_of(y).trim().is_empty()
-        },
-    ];
-    for pass in passes {
+            if let Some(k) = key(sb, text_b.get(j).map_or("", String::as_str)) {
+                index.entry(k).or_default().push_back(j);
+            }
+        }
+        if index.is_empty() {
+            continue;
+        }
         for (i, sa) in a.shapes.iter().enumerate() {
             if used_a.get(i).copied().unwrap_or(true) {
                 continue;
             }
-            let found = b.shapes.iter().enumerate().find(|(j, sb)| !used_b.get(*j).copied().unwrap_or(true) && pass(sa, sb));
-            if let Some((j, sb)) = found {
-                if let Some(u) = used_a.get_mut(i) {
-                    *u = true;
-                }
-                if let Some(u) = used_b.get_mut(j) {
-                    *u = true;
-                }
-                pairs.push((sa.id, sb.id));
+            let Some(k) = key(sa, text_a.get(i).map_or("", String::as_str)) else { continue };
+            let Some(j) = index.get_mut(&k).and_then(VecDeque::pop_front) else { continue };
+            let Some(sb) = b.shapes.get(j) else { continue };
+            if let Some(u) = used_a.get_mut(i) {
+                *u = true;
             }
+            if let Some(u) = used_b.get_mut(j) {
+                *u = true;
+            }
+            pairs.push((sa.id, sb.id));
         }
     }
     pairs
 }
 
+/// What one [`morph_pairs`] pass matches shapes on.
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+enum MorphKey {
+    Name(String),
+    Text(&'static str, String),
+    Geom(&'static str, String),
+}
+
 fn lerp(a: f64, b: f64, t: f64) -> f64 {
     let v = a + (b - a) * t;
     if v.is_finite() {
@@ -256,13 +276,23 @@ pub fn morph_frame(pres: &Presentation, a: &Slide, b: &Slide, t: f64, hidden_b:
         f.shapes.push((sh, old));
         id
     };
+    // Lookups by id, built once (the first shape or pair with an id wins, as a search would).
+    let paired_a: HashSet<ShapeId> = pairs.iter().map(|(ia, _)| *ia).collect();
+    let mut partner: HashMap<ShapeId, ShapeId> = HashMap::with_capacity(pairs.len());
+    for (ia, ib) in &pairs {
+        partner.entry(*ib).or_insert(*ia);
+    }
+    let mut a_by_id: HashMap<ShapeId, &Shape> = HashMap::with_capacity(a.shapes.len());
+    for x in &a.shapes {
+        a_by_id.entry(x.id).or_insert(x);
+    }
     for sa in &a.shapes {
-        if !pairs.iter().any(|(ia, _)| *ia == sa.id) {
+        if !paired_a.contains(&sa.id) {
             push(sa.clone(), true, 1.0 - s);
         }
     }
     for sb in &b.shapes {
-        let pair = pairs.iter().find(|(_, ib)| *ib == sb.id).and_then(|(ia, _)| a.shapes.iter().find(|x| x.id == *ia));
+        let pair = partner.get(&sb.id).and_then(|ia| a_by_id.get(ia).copied());
         let Some(sa) = pair else {
             if !hidden_b(sb.id) {
                 push(sb.clone(), false, s);

crates/anim/src/tests.rs

@@ -1155,3 +1155,58 @@ fn many_by_paragraph_animations_on_one_shape_share_paragraph_targets() {
     assert_eq!(tl.effects().len(), 6_000);
     assert_eq!(tl.paragraph_targets(ShapeId(1)), vec![0, 1, 2]);
 }
+
+#[test]
+fn morph_pairs_take_the_first_unused_match_in_slide_order() {
+    let mut a = Slide::default();
+    let mut b = Slide::default();
+    a.shapes = vec![shape(1, "Same"), shape(2, "Same"), shape(3, "Other")];
+    b.shapes = vec![shape(11, "Same"), shape(12, "Same"), shape(13, "Same")];
+    // By name first, in slide order; the shape of `a` left over pairs by kind and geometry with
+    // the shape of `b` left over.
+    assert_eq!(morph_pairs(&a, &b), [(ShapeId(1), ShapeId(11)), (ShapeId(2), ShapeId(12)), (ShapeId(3), ShapeId(13))]);
+}
+
+#[test]
+fn morph_of_large_slides_stays_linear() {
+    let n = 20_000u32;
+    let text = |i: u32, side: &str| Some(TextBody::from_text(&format!("{side} {i}")));
+    let mut a = Slide::default();
+    let mut b = Slide::default();
+    // Text no shape on the other slide shares: every pass looks for a partner and finds none.
+    a.shapes = (0..n).map(|i| Shape { text: text(i, "a"), ..shape(i + 1, "") }).collect();
+    b.shapes = (0..n).map(|i| Shape { text: text(i, "b"), ..shape(n + i + 1, "") }).collect();
+    // One named pair at opposite ends.
+    a.shapes[0].name = "Logo".into();
+    b.shapes[n as usize - 1].name = "Logo".into();
+    // No wall-clock bound (it would flake on a loaded runner): at this size a quadratic pairing
+    // takes minutes, so a regression shows as a test that hangs rather than a failed assertion.
+    assert_eq!(morph_pairs(&a, &b), [(ShapeId(1), ShapeId(2 * n))]);
+    let p = deckcraft_model::defaults::new_presentation(None);
+    let f = morph_frame(&p, &a, &b, 0.5, &|_| false);
+    // Every shape fades in place; the named pair differs in text, so it cross-fades as two.
+    assert_eq!(f.shapes.len(), 2 * n as usize);
+}
+
+#[test]
+fn paragraph_states_of_a_large_build_stay_linear() {
+    let n = 20_000usize;
+    let mut s = slide_with(vec![]);
+    let mut body = TextBody::from_text(&vec!["line"; n].join("\n"));
+    // One first-level paragraph owning every other paragraph.
+    for p in body.paragraphs.iter_mut().skip(1) {
+        p.level = 1;
+    }
+    s.shapes[0].text = Some(body);
+    let mut a = anim(1, AnimClass::Entrance, "fade", AnimStart::OnClick);
+    a.text_build = TextBuild::ByParagraph;
+    s.animations = vec![a];
+    let tl = Timeline::new(&s, W, H);
+    // No wall-clock bound, as above: a per-paragraph scan of the slide would take minutes here.
+    assert_eq!(tl.paragraph_targets(ShapeId(1)).len(), n);
+    for p in 0..n {
+        assert!(!tl.state(ShapeId(1), Some(p), 0, 0.0).visible);
+        assert!(tl.state(ShapeId(1), Some(p), 1, 0.0).visible);
+    }
+    assert_eq!(tl.animated_shapes(), [ShapeId(1)]);
+}

crates/anim/src/timeline.rs

@@ -103,6 +103,41 @@ pub struct Timeline {
     /// By-paragraph builds animate first-level paragraphs; deeper paragraphs follow their parent:
     /// (shape, member paragraph, owner paragraph).
     groups: Vec<(ShapeId, usize, usize)>,
+    /// Lookups built with the timeline, so evaluating a shape or paragraph costs its own effects
+    /// rather than a scan of every effect, group and colour on the slide.
+    index: TimelineIndex,
+}
+
+#[derive(Clone, Debug, Default)]
+struct TimelineIndex {
+    /// Effects (indices into `effects`, in order) by target shape and paragraph.
+    by_target: HashMap<(ShapeId, Option<usize>), Vec<usize>>,
+    /// Effects (indices into `effects`, in order) by target shape.
+    by_shape: HashMap<ShapeId, Vec<usize>>,
+    /// Owner paragraph of each member paragraph (the first group recorded wins).
+    owner: HashMap<(ShapeId, usize), usize>,
+    /// Groups (member, owner) by shape, in order.
+    groups_by_shape: HashMap<ShapeId, Vec<(usize, usize)>>,
+    /// Base colour by shape (the first recorded wins).
+    color: HashMap<ShapeId, Rgba>,
+}
+
+impl TimelineIndex {
+    fn build(effects: &[Effect], groups: &[(ShapeId, usize, usize)], colors: &[(ShapeId, Rgba)]) -> TimelineIndex {
+        let mut ix = TimelineIndex::default();
+        for (i, e) in effects.iter().enumerate() {
+            ix.by_target.entry((e.timing.shape, e.timing.paragraph)).or_default().push(i);
+            ix.by_shape.entry(e.timing.shape).or_default().push(i);
+        }
+        for &(shape, member, owner) in groups {
+            ix.owner.entry((shape, member)).or_insert(owner);
+            ix.groups_by_shape.entry(shape).or_default().push((member, owner));
+        }
+        for &(shape, c) in colors {
+            ix.color.entry(shape).or_insert(c);
+        }
+        ix
+    }
 }
 
 enum Status {
@@ -324,6 +359,7 @@ impl Timeline {
             };
             tl.colors.push((id, c));
         }
+        tl.index = TimelineIndex::build(&tl.effects, &tl.groups, &tl.colors);
         tl
     }
 
@@ -413,8 +449,12 @@ impl Timeline {
 
     /// Paragraph indices of `shape` animated separately (by-paragraph builds).
     pub fn paragraph_targets(&self, shape: ShapeId) -> Vec<usize> {
-        let mut v: Vec<usize> = self.effects.iter().filter(|e| e.timing.shape == shape).filter_map(|e| e.timing.paragraph).collect();
-        v.extend(self.groups.iter().filter(|g| g.0 == shape && v.contains(&g.2)).map(|g| g.1).collect::<Vec<_>>());
+        let mine = self.index.by_shape.get(&shape).map_or(&[][..], Vec::as_slice);
+        let mut v: Vec<usize> = mine.iter().filter_map(|&i| self.effects.get(i)).filter_map(|e| e.timing.paragraph).collect();
+        let owners: HashSet<usize> = v.iter().copied().collect();
+        if let Some(groups) = self.index.groups_by_shape.get(&shape) {
+            v.extend(groups.iter().filter(|(_, owner)| owners.contains(owner)).map(|(member, _)| *member));
+        }
         v.sort_unstable();
         v.dedup();
         v
@@ -422,13 +462,8 @@ impl Timeline {
 
     /// Shapes with any effect.
     pub fn animated_shapes(&self) -> Vec<ShapeId> {
-        let mut v: Vec<ShapeId> = Vec::new();
-        for e in &self.effects {
-            if !v.contains(&e.timing.shape) {
-                v.push(e.timing.shape);
-            }
-        }
-        v
+        let mut seen: HashSet<ShapeId> = HashSet::new();
+        self.effects.iter().map(|e| e.timing.shape).filter(|s| seen.insert(*s)).collect()
     }
 
     /// State of `shape` (or of one of its paragraphs, `para`) when `step` main steps have been
@@ -456,9 +491,9 @@ impl Timeline {
         triggers: &[TriggerPlay],
         stamps: &[StepStamp],
     ) -> AnimState {
-        let para = para.map(|p| self.groups.iter().find(|g| g.0 == shape && g.1 == p).map(|g| g.2).unwrap_or(p));
-        let mine = self.effects.iter().filter(|e| e.timing.shape == shape && e.timing.paragraph == para);
-        let base_color = self.colors.iter().find(|(s, _)| *s == shape).map(|(_, c)| *c).unwrap_or(Rgba::rgb(0x15, 0x60, 0x82));
+        let para = para.map(|p| self.index.owner.get(&(shape, p)).copied().unwrap_or(p));
+        let mine = self.index.by_target.get(&(shape, para)).map_or(&[][..], Vec::as_slice).iter().filter_map(|&i| self.effects.get(i));
+        let base_color = self.index.color.get(&shape).copied().unwrap_or(Rgba::rgb(0x15, 0x60, 0x82));
         let mut st = AnimState::default();
         // Initial visibility comes from the first effect in the Animation Pane order.
         let mut ordered: Vec<&Effect> = mine.collect();

crates/fonts/src/fallback.rs

@@ -227,9 +227,6 @@ impl FontDb {
     }
 }
 
-/// Most caret records read for one ligature glyph.
-const MAX_LIGATURE_CARETS: usize = 64;
-
 /// Caret positions inside a ligature glyph from GDEF `LigCaretList`, in font units from the
 /// glyph's origin (sorted ascending). Empty when the font has none for `gid`.
 pub fn ligature_carets(face: &FontFace, gid: u32) -> Vec<i32> {
@@ -239,12 +236,9 @@ pub fn ligature_carets(face: &FontFace, gid: u32) -> Vec<i32> {
     let Ok(cov) = list.coverage() else { return Vec::new() };
     let Some(idx) = cov.get(skrifa::GlyphId::new(gid)) else { return Vec::new() };
     let Ok(lig) = list.lig_glyphs().get(idx as usize) else { return Vec::new() };
-    // The limit applies to the records read, not to the carets kept: a font can list thousands of
-    // records it then has to be read through for every ligature laid out.
     let mut out: Vec<i32> = lig
         .caret_values()
         .iter()
-        .take(MAX_LIGATURE_CARETS)
         .filter_map(|cv| cv.ok())
         .filter_map(|cv| match cv {
             skrifa::raw::tables::gdef::CaretValue::Format1(f) => Some(f.coordinate() as i32),
@@ -252,6 +246,7 @@ pub fn ligature_carets(face: &FontFace, gid: u32) -> Vec<i32> {
             // Format 2 is a contour point index; outlines aren't consulted here.
             skrifa::raw::tables::gdef::CaretValue::Format2(_) => None,
         })
+        .take(64)
         .collect();
     out.sort_unstable();
     out

crates/fonts/src/fontdb.rs

@@ -368,7 +368,7 @@ struct CatalogEntry {
 /// Process-wide font database.
 pub struct FontDb {
     faces: RwLock<Vec<Arc<FontFace>>>,
-    outlines: Mutex<OutlineCache>,
+    outlines: Mutex<HashMap<(u32, u32), Arc<BezPath>>>,
     #[cfg(not(target_arch = "wasm32"))]
     catalog: RwLock<Vec<CatalogEntry>>,
     /// The folders the system font scan reads (the platform's font folders for [`FontDb::global`]).
@@ -439,38 +439,6 @@ const SYSTEM_FALLBACKS: &[&str] = &[
 
 static NEXT_ID: AtomicU32 = AtomicU32::new(1);
 const OUTLINE_CACHE_MAX: usize = 50_000;
-/// Most path elements one glyph outline may expand to. Composite and `VARC` glyphs can draw a
-/// shared outline many times over; a glyph past this draws nothing rather than holding megabytes.
-const MAX_OUTLINE_ELEMENTS: usize = 1 << 15;
-/// Most path elements the outline cache holds across all glyphs (about 230 MB at most) before it
-/// starts over: distinct glyph ids can each expand one dense outline.
-const OUTLINE_CACHE_MAX_ELEMENTS: usize = 1 << 22;
-
-/// Glyph outlines by (face, glyph), with the path elements they hold.
-#[derive(Default)]
-struct OutlineCache {
-    paths: HashMap<(u32, u32), Arc<BezPath>>,
-    elements: usize,
-}
-
-impl OutlineCache {
-    fn get(&self, key: &(u32, u32)) -> Option<Arc<BezPath>> {
-        self.paths.get(key).cloned()
-    }
-
-    fn insert(&mut self, key: (u32, u32), path: Arc<BezPath>) {
-        let n = path.elements().len();
-        if let Some(old) = self.paths.remove(&key) {
-            self.elements = self.elements.saturating_sub(old.elements().len());
-        }
-        if self.paths.len() >= OUTLINE_CACHE_MAX || self.elements.saturating_add(n) > OUTLINE_CACHE_MAX_ELEMENTS {
-            self.paths.clear();
-            self.elements = 0;
-        }
-        self.paths.insert(key, path);
-        self.elements = self.elements.saturating_add(n);
-    }
-}
 
 fn name(font: &skrifa::FontRef<'_>, ids: &[StringId]) -> Option<String> {
     ids.iter().find_map(|id| font.localized_strings(*id).english_or_first().map(|s| s.to_string()).filter(|s| !s.is_empty()))
@@ -726,10 +694,6 @@ const MAX_COLLECTION_FACES: u32 = 256;
 const MAX_COLLECTION_ENTRIES_SCANNED: u32 = 16_384;
 /// Maximum named instances read from a single face.
 const MAX_NAMED_INSTANCES_PER_FACE: usize = 1024;
-/// Maximum faces (named instances counted separately) enumerated from one font file, across all
-/// of a collection's faces: the per-collection and per-face limits multiply, and each face found
-/// is then built with its own shaper.
-const MAX_ENUMERATED_FACES: usize = 4096;
 
 fn distinct_face_indices(entries: impl IntoIterator<Item = (u32, u32)>) -> Vec<u32> {
     let mut offsets = std::collections::HashSet::new();
@@ -766,30 +730,21 @@ fn enumerate_faces(data: &[u8]) -> Vec<Found> {
         Err(_) => Vec::new(),
     };
     let mut out = Vec::new();
-    // Named instances read and plain faces kept, across the whole file.
-    let mut budget = MAX_ENUMERATED_FACES;
     for i in indices {
-        if budget == 0 {
-            break;
-        }
         let Ok(f) = skrifa::FontRef::from_index(data, i) else { continue };
         let Some((family, style)) = face_names(&f) else { continue };
         let axes = f.axes();
         let mut named = Vec::new();
-        let mut seen = std::collections::HashSet::new();
         let instances = f.named_instances();
         for ni in instances.iter().take(capped_named_instance_count(instances.len())) {
-            let Some(left) = budget.checked_sub(1) else { break };
-            budget = left;
             let Some(style) = name(&f, &[ni.subfamily_name_id()]) else { continue };
-            if !seen.insert(style.to_ascii_lowercase()) {
+            if named.iter().any(|(_, s, _): &(u32, String, _)| s.eq_ignore_ascii_case(&style)) {
                 continue;
             }
             let coords: Vec<([u8; 4], f32)> = axes.iter().zip(ni.user_coords()).map(|(a, v)| (a.tag().to_be_bytes(), v)).collect();
             named.push((i, style, coords));
         }
         if named.is_empty() {
-            budget = budget.saturating_sub(1);
             out.push((i, family, style, Vec::new()));
         } else {
             out.extend(named.into_iter().map(|(i, s, c)| (i, family.clone(), s, c)));
@@ -950,7 +905,7 @@ impl FontDb {
         }
         Self {
             faces: RwLock::new(faces),
-            outlines: Mutex::new(OutlineCache::default()),
+            outlines: Mutex::new(HashMap::new()),
             #[cfg(not(target_arch = "wasm32"))]
             catalog: RwLock::new(Vec::new()),
             font_dirs,
@@ -1558,72 +1513,41 @@ impl FontDb {
     pub fn outline(&self, face: &FontFace, gid: u32) -> Arc<BezPath> {
         let key = (face.id, gid);
         if let Some(p) = self.outlines.lock().unwrap_or_else(std::sync::PoisonError::into_inner).get(&key) {
-            return p;
+            return p.clone();
         }
-        let mut pen = FlipPen::new(MAX_OUTLINE_ELEMENTS);
+        let mut pen = FlipPen(BezPath::new());
         if let Some(f) = face.skrifa()
             && let Some(g) = f.outline_glyphs().get(GlyphId::new(gid))
         {
             let _ = g.draw(DrawSettings::unhinted(Size::unscaled(), face.location()), &mut pen);
         }
-        let p = Arc::new(pen.finish());
-        self.outlines.lock().unwrap_or_else(std::sync::PoisonError::into_inner).insert(key, p.clone());
+        let p = Arc::new(pen.0);
+        let mut cache = self.outlines.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
+        if cache.len() >= OUTLINE_CACHE_MAX {
+            cache.clear();
+        }
+        cache.insert(key, p.clone());
         p
     }
 }
 
-/// Collects a glyph outline, y flipped, up to `limit` path elements. Past the limit it ignores
-/// what follows and [`FlipPen::finish`] gives an empty path: a cut-off outline would fill wrongly.
-struct FlipPen {
-    path: BezPath,
-    limit: usize,
-    over: bool,
-}
-
-impl FlipPen {
-    fn new(limit: usize) -> Self {
-        FlipPen { path: BezPath::new(), limit, over: false }
-    }
-
-    /// Room for one more element?
-    fn room(&mut self) -> bool {
-        if !self.over && self.path.elements().len() >= self.limit {
-            self.over = true;
-            self.path = BezPath::new();
-        }
-        !self.over
-    }
-
-    fn finish(self) -> BezPath {
-        if self.over { BezPath::new() } else { self.path }
-    }
-}
+struct FlipPen(BezPath);
 
 impl OutlinePen for FlipPen {
     fn move_to(&mut self, x: f32, y: f32) {
-        if self.room() {
-            self.path.move_to((x as f64, -y as f64));
-        }
+        self.0.move_to((x as f64, -y as f64));
     }
     fn line_to(&mut self, x: f32, y: f32) {
-        if self.room() {
-            self.path.line_to((x as f64, -y as f64));
-        }
+        self.0.line_to((x as f64, -y as f64));
     }
     fn quad_to(&mut self, cx0: f32, cy0: f32, x: f32, y: f32) {
-        if self.room() {
-            self.path.quad_to((cx0 as f64, -cy0 as f64), (x as f64, -y as f64));
-        }
+        self.0.quad_to((cx0 as f64, -cy0 as f64), (x as f64, -y as f64));
     }
     fn curve_to(&mut self, cx0: f32, cy0: f32, cx1: f32, cy1: f32, x: f32, y: f32) {
-        if self.room() {
-            self.path.curve_to((cx0 as f64, -cy0 as f64), (cx1 as f64, -cy1 as f64), (x as f64, -y as f64));
-        }
+        self.0.curve_to((cx0 as f64, -cy0 as f64), (cx1 as f64, -cy1 as f64), (x as f64, -y as f64));
     }
     fn close(&mut self) {
-        if self.room() {
-            self.path.close_path();
-        }
+        self.0.close_path();
     }
 }
 
@@ -1651,55 +1575,6 @@ mod font_dir_tests {
         assert_eq!(capped_named_instance_count(MAX_NAMED_INSTANCES_PER_FACE + 1), MAX_NAMED_INSTANCES_PER_FACE);
     }
 
-    #[test]
-    fn faces_of_one_file_are_bounded_across_the_collection() {
-        // The per-collection and per-face limits together would allow far more.
-        assert!((MAX_COLLECTION_FACES as usize) * MAX_NAMED_INSTANCES_PER_FACE > 16 * MAX_ENUMERATED_FACES);
-        for data in bundled() {
-            assert!(enumerate_faces(data).len() <= MAX_ENUMERATED_FACES);
-        }
-    }
-
-    #[test]
-    fn an_outline_past_the_element_limit_draws_nothing() {
-        let mut pen = FlipPen::new(8);
-        pen.move_to(0.0, 0.0);
-        pen.line_to(1.0, 1.0);
-        pen.close();
-        assert_eq!(pen.finish().elements().len(), 3);
-        // A shared outline drawn over and over (composite and VARC glyphs).
-        let mut pen = FlipPen::new(8);
-        for i in 0..1_000_000 {
-            pen.move_to(0.0, 0.0);
-            pen.line_to(i as f32, 1.0);
-            pen.close();
-        }
-        assert_eq!(pen.path.elements().len(), 0);
-        assert!(pen.finish().elements().is_empty());
-    }
-
-    #[test]
-    fn outline_cache_is_bounded_by_elements() {
-        let mut path = BezPath::new();
-        path.move_to((0.0, 0.0));
-        for i in 1..MAX_OUTLINE_ELEMENTS {
-            path.line_to((i as f64, 0.0));
-        }
-        let path = Arc::new(path);
-        let mut cache = OutlineCache::default();
-        let glyphs = 4 * OUTLINE_CACHE_MAX_ELEMENTS / MAX_OUTLINE_ELEMENTS;
-        for gid in 0..glyphs as u32 {
-            cache.insert((1, gid), path.clone());
-            assert!(cache.elements <= OUTLINE_CACHE_MAX_ELEMENTS);
-            assert_eq!(cache.elements, cache.paths.values().map(|p| p.elements().len()).sum::<usize>());
-        }
-        assert!(cache.get(&(1, glyphs as u32 - 1)).is_some());
-        // Replacing an entry does not count it twice.
-        let before = cache.elements;
-        cache.insert((1, glyphs as u32 - 1), path.clone());
-        assert_eq!(cache.elements, before);
-    }
-
     #[test]
     fn xdg_data_dirs_contribute_their_fonts_folders() {
         let home = Path::new("/home/ann");

crates/fonts/src/shape.rs

@@ -37,56 +37,146 @@ pub struct ShapeParams<'a> {
     pub language: Option<&'a str>,
 }
 
+/// Most bytes of text given to the shaper at once. The shaper lets one call grow its buffers to
+/// 256 glyphs per character (a font's substitutions decide how many), so a long item is shaped in
+/// pieces of this size, each with the rest of the paragraph as context.
+const MAX_SHAPE_CHUNK: usize = 1024;
+/// Most glyphs kept per character of a piece: a piece the font expands further is laid out one
+/// glyph per character from the cmap instead.
+const MAX_GLYPHS_PER_CHAR: usize = 32;
+
 /// Shape `para[range]` with `face`, the rest of `para` as context. Glyphs are in visual order
 /// (left to right) and clusters are byte offsets into `para`. `map` substitutes characters (All
 /// Caps) without moving clusters. An empty or out-of-bounds range shapes nothing.
 pub fn shape_range(face: &FontFace, para: &str, range: Range<usize>, params: &ShapeParams, map: impl Fn(char) -> char) -> Vec<ShapedGlyph> {
-    let (Some(pre), Some(text), Some(post)) = (para.get(..range.start), para.get(range.clone()), para.get(range.end..)) else {
+    let (Some(_), Some(text), Some(_)) = (para.get(..range.start), para.get(range.clone()), para.get(range.end..)) else {
         return Vec::new();
     };
-    let mut out = Vec::with_capacity(text.len());
+    let chunks = chunks(text, MAX_SHAPE_CHUNK);
+    let mut pieces: Vec<Vec<ShapedGlyph>> = Vec::with_capacity(chunks.len());
     let shaped = face.hb().map(|hb| {
         let shaper = face.shaper.shaper(&hb).instance(face.instance.as_ref()).build();
-        let mut buf = UnicodeBuffer::new();
-        buf.set_pre_context(pre);
-        buf.set_post_context(post);
-        for (i, c) in text.char_indices() {
-            buf.add(map(c), (range.start + i) as u32);
-        }
-        buf.guess_segment_properties();
-        if let Some(s) = params.script.and_then(|t| Script::from_iso15924_tag(Tag::new(&t))) {
-            buf.set_script(s);
-        }
-        if let Some(l) = params.language.or_else(|| params.script.and_then(crate::script::default_language)).and_then(|l| l.parse::<Language>().ok())
-        {
-            buf.set_language(l);
-        }
-        buf.set_direction(if params.rtl { Direction::RightToLeft } else { Direction::LeftToRight });
-        let gb = shaper.shape(buf, ShapeOptions::new().features(params.features));
-        for (info, pos) in gb.glyph_infos().iter().zip(gb.glyph_positions()) {
-            out.push(ShapedGlyph {
-                gid: info.glyph_id,
-                cluster: info.cluster as usize,
-                x_advance: pos.x_advance,
-                x_offset: pos.x_offset,
-                y_offset: pos.y_offset,
-            });
+        // Pieces of one item share the script the whole item would be guessed to have.
+        let item_script = (chunks.len() > 1 && params.script.is_none()).then(|| {
+            let mut probe = UnicodeBuffer::new();
+            for c in text.chars() {
+                probe.add(map(c), 0);
+            }
+            probe.guess_segment_properties();
+            probe.script()
+        });
+        for c in &chunks {
+            let r = (range.start + c.start)..(range.start + c.end);
+            let (Some(pre), Some(piece), Some(post)) = (para.get(..r.start), para.get(r.clone()), para.get(r.end..)) else { continue };
+            let mut buf = UnicodeBuffer::new();
+            buf.set_pre_context(pre);
+            buf.set_post_context(post);
+            for (i, c) in piece.char_indices() {
+                buf.add(map(c), (r.start + i) as u32);
+            }
+            buf.guess_segment_properties();
+            if let Some(s) = params.script.and_then(|t| Script::from_iso15924_tag(Tag::new(&t))) {
+                buf.set_script(s);
+            } else if let Some(s) = item_script {
+                buf.set_script(s);
+            }
+            if let Some(l) =
+                params.language.or_else(|| params.script.and_then(crate::script::default_language)).and_then(|l| l.parse::<Language>().ok())
+            {
+                buf.set_language(l);
+            }
+            buf.set_direction(if params.rtl { Direction::RightToLeft } else { Direction::LeftToRight });
+            let gb = shaper.shape(buf, ShapeOptions::new().features(params.features));
+            let budget = piece.chars().count().saturating_mul(MAX_GLYPHS_PER_CHAR);
+            if gb.len() > budget {
+                // Font-controlled expansion past anything real text needs: keep it bounded.
+                pieces.push(cmap_glyphs(face, para, r, params.rtl, &map));
+                continue;
+            }
+            pieces.push(
+                gb.glyph_infos()
+                    .iter()
+                    .zip(gb.glyph_positions())
+                    .map(|(info, pos)| ShapedGlyph {
+                        gid: info.glyph_id,
+                        cluster: info.cluster as usize,
+                        x_advance: pos.x_advance,
+                        x_offset: pos.x_offset,
+                        y_offset: pos.y_offset,
+                    })
+                    .collect(),
+            );
         }
     });
-    if shaped.is_none()
-        && let Some(f) = face.skrifa()
-    {
+    if shaped.is_none() {
         // No shaper for this face: one glyph per character from the cmap, in visual order.
-        let cmap = f.charmap();
-        let gm = f.glyph_metrics(Size::unscaled(), face.location());
-        for (i, c) in text.char_indices() {
-            let g = cmap.map(map(c)).unwrap_or_default();
-            let adv = gm.advance_width(g).unwrap_or(face.upem as f32 * 0.5);
-            out.push(ShapedGlyph { gid: g.to_u32(), cluster: range.start + i, x_advance: adv.round() as i32, x_offset: 0, y_offset: 0 });
-        }
-        if params.rtl {
-            out.reverse();
+        return cmap_glyphs(face, para, range, params.rtl, &map);
+    }
+    // Each piece is in visual order; right to left, the later pieces come first.
+    if params.rtl {
+        pieces.reverse();
+    }
+    let mut out = Vec::with_capacity(pieces.iter().map(Vec::len).sum());
+    for p in pieces {
+        out.extend(p);
+    }
+    out
+}
+
+/// One glyph per character of `para[range]` from the cmap, in visual order.
+fn cmap_glyphs(face: &FontFace, para: &str, range: Range<usize>, rtl: bool, map: &impl Fn(char) -> char) -> Vec<ShapedGlyph> {
+    let (Some(text), Some(f)) = (para.get(range.clone()), face.skrifa()) else { return Vec::new() };
+    let cmap = f.charmap();
+    let gm = f.glyph_metrics(Size::unscaled(), face.location());
+    let mut out = Vec::with_capacity(text.len());
+    for (i, c) in text.char_indices() {
+        let g = cmap.map(map(c)).unwrap_or_default();
+        let adv = gm.advance_width(g).unwrap_or(face.upem as f32 * 0.5);
+        out.push(ShapedGlyph { gid: g.to_u32(), cluster: range.start + i, x_advance: adv.round() as i32, x_offset: 0, y_offset: 0 });
+    }
+    if rtl {
+        out.reverse();
+    }
+    out
+}
+
+/// `text` cut into byte ranges of at most `max` bytes (or one character, if longer), at the last
+/// space of a piece where there is one, else before a character that starts a cluster (not a
+/// combining mark or joiner, not after a joiner). Text that fits is one piece.
+fn chunks(text: &str, max: usize) -> Vec<Range<usize>> {
+    use unicode_bidi::BidiClass::{BN, NSM};
+    let mut out = Vec::new();
+    let mut start = 0;
+    while text.len() - start > max {
+        let window = text.get(start..).unwrap_or_default();
+        let mut space = None;
+        let mut boundary = None;
+        let mut any = None;
+        let mut prev: Option<char> = None;
+        for (i, c) in window.char_indices() {
+            if i > max {
+                break;
+            }
+            if i > 0 {
+                any = Some(i);
+                let joined = prev.is_some_and(|p| matches!(unicode_bidi::bidi_class(p), BN));
+                if !joined && !matches!(unicode_bidi::bidi_class(c), NSM | BN) {
+                    boundary = Some(i);
+                    if prev.is_some_and(char::is_whitespace) {
+                        space = Some(i);
+                    }
+                }
+            }
+            prev = Some(c);
         }
+        // A piece always moves forward by at least one character.
+        let first = window.chars().next().map_or(window.len(), char::len_utf8);
+        let cut = space.filter(|&i| i >= max / 2).or(boundary).or(any).unwrap_or(first).max(first);
+        out.push(start..start + cut);
+        start += cut;
+    }
+    if start < text.len() || out.is_empty() {
+        out.push(start..text.len());
     }
     out
 }
@@ -121,4 +211,37 @@ mod tests {
         // Not a char boundary.
         assert!(shape_range(&face, "سنة", 1..2, &ShapeParams::default(), |c| c).is_empty());
     }
+
+    #[test]
+    fn long_items_are_shaped_in_bounded_pieces() {
+        for text in ["word ".repeat(2_000), "e\u{301}".repeat(2_000), "x".repeat(5_000), "\u{1f469}\u{200d}\u{1f4bb} ".repeat(500)] {
+            let pieces = chunks(&text, MAX_SHAPE_CHUNK);
+            assert_eq!(pieces.first().map(|r| r.start), Some(0));
+            assert_eq!(pieces.last().map(|r| r.end), Some(text.len()));
+            for w in pieces.windows(2) {
+                assert_eq!(w[0].end, w[1].start);
+            }
+            for r in &pieces {
+                assert!(!r.is_empty() && r.len() <= MAX_SHAPE_CHUNK);
+                // Never before a combining mark, never after a joiner.
+                let rest = &text[r.end..];
+                assert!(!rest.starts_with('\u{301}'));
+                assert!(!text[..r.end].ends_with('\u{200d}') || rest.is_empty());
+            }
+        }
+        assert_eq!(chunks("short", MAX_SHAPE_CHUNK), vec![0..5]);
+        assert_eq!(chunks("", MAX_SHAPE_CHUNK), vec![0..0]);
+    }
+
+    #[test]
+    fn long_items_keep_every_cluster_in_visual_order() {
+        let face = FontDb::global().face(DEFAULT_FAMILY, "Regular");
+        let text = "ab cd ".repeat(1_000);
+        let g = shape_range(&face, &text, 0..text.len(), &ShapeParams::default(), |c| c);
+        assert_eq!(g.len(), text.len());
+        assert!(g.windows(2).all(|w| w[0].cluster < w[1].cluster));
+        let rtl = shape_range(&face, &text, 0..text.len(), &ShapeParams { rtl: true, ..Default::default() }, |c| c);
+        assert_eq!(rtl.len(), text.len());
+        assert!(rtl.windows(2).all(|w| w[0].cluster > w[1].cluster));
+    }
 }

crates/pptx/src/tables.rs

@@ -210,13 +210,20 @@ pub fn table_styles_xml(used: &[String], defs: &[deckcraft_model::table::TableSt
     let mut w = W::new();
     w.open("a:tblStyleLst", A::new().a("xmlns:a", NS_A).a("def", "{5C22544A-7EE6-4342-B048-85BDC9FD1C3A}"));
     let names = deckcraft_model::table::table_styles();
-    let mut done: Vec<&str> = vec![];
+    // Indexes instead of scans: written ids (as given and ASCII lower-case), and the file's
+    // definitions by lower-case id (the first wins).
+    let mut done: std::collections::HashSet<&str> = std::collections::HashSet::new();
+    let mut done_lower: std::collections::HashSet<String> = std::collections::HashSet::new();
+    let mut def_of: std::collections::HashMap<String, &deckcraft_model::table::TableStyleDef> = std::collections::HashMap::new();
+    for d in defs {
+        def_of.entry(d.id.to_ascii_lowercase()).or_insert(d);
+    }
     for s in used {
-        if done.contains(&s.as_str()) {
+        if !done.insert(s.as_str()) {
             continue;
         }
-        done.push(s);
-        if let Some(d) = defs.iter().find(|d| d.id.eq_ignore_ascii_case(s))
+        done_lower.insert(s.to_ascii_lowercase());
+        if let Some(d) = def_of.get(&s.to_ascii_lowercase())
             && crate::xml::parse(d.raw.as_bytes()).is_ok_and(|x| x.root.is("tblStyle"))
         {
             w.raw(&d.raw);
@@ -231,11 +238,11 @@ pub fn table_styles_xml(used: &[String], defs: &[deckcraft_model::table::TableSt
     }
     // Styles the file defined but no table uses still belong to the deck.
     for d in defs {
-        if done.iter().any(|s| s.eq_ignore_ascii_case(&d.id)) {
+        if done_lower.contains(&d.id.to_ascii_lowercase()) {
             continue;
         }
         if crate::xml::parse(d.raw.as_bytes()).is_ok_and(|x| x.root.is("tblStyle")) {
-            done.push(&d.id);
+            done_lower.insert(d.id.to_ascii_lowercase());
             w.raw(&d.raw);
         }
     }

crates/pptx/src/write.rs

@@ -53,6 +53,8 @@ pub struct Exp<'a> {
     pub p: &'a Presentation,
     pub pkg: PackageOut,
     media_parts: HashMap<MediaId, String>,
+    /// Each media id's item in `p.media` (the first with the id, as `Presentation::media`).
+    media_at: HashMap<MediaId, usize>,
     n_image: u32,
     n_media: u32,
     n_chart: u32,
@@ -63,6 +65,8 @@ pub struct Exp<'a> {
     n_kept: u32,
     pub slide_parts: HashMap<SlideId, String>,
     pub table_styles: Vec<String>,
+    /// The ids in `table_styles`, for checking membership without a scan.
+    pub table_style_set: std::collections::HashSet<String>,
     placeholder: Option<String>,
 }
 
@@ -119,12 +123,17 @@ fn ext_for(content_type: &str, name: &str, data: &[u8]) -> String {
     if !e.is_empty() && e.len() <= 5 && e.chars().all(|c| c.is_ascii_alphanumeric()) { e } else { "bin".into() }
 }
 
-impl Exp<'_> {
+impl<'a> Exp<'a> {
+    /// The media item `id`, found through the index rather than a scan of every item.
+    pub fn media(&self, id: MediaId) -> Option<&'a deckcraft_model::MediaItem> {
+        let p: &'a Presentation = self.p;
+        self.media_at.get(&id).and_then(|&i| p.media.get(i))
+    }
     fn media_part(&mut self, id: MediaId) -> Option<String> {
         if let Some(p) = self.media_parts.get(&id) {
             return Some(p.clone());
         }
-        let m = self.p.media(id)?;
+        let m = self.media(id)?;
         if m.data.is_empty() {
             return None;
         }
@@ -147,7 +156,7 @@ impl Exp<'_> {
     }
     /// A relationship from `o` to a media item (embedded part, or external link).
     pub fn media_rel(&mut self, o: &mut Out, id: MediaId, kind: &str) -> Option<String> {
-        let m = self.p.media(id)?;
+        let m = self.media(id)?;
         if m.data.is_empty() {
             let link = m.link.clone()?;
             return Some(o.rels.add(kind, &link, true));
@@ -156,7 +165,7 @@ impl Exp<'_> {
         Some(o.rels.add(kind, &opc::relative(&o.name, &part), false))
     }
     pub fn media_rel_new(&mut self, o: &mut Out, id: MediaId, kind: &str) -> Option<String> {
-        let m = self.p.media(id)?;
+        let m = self.media(id)?;
         if m.data.is_empty() {
             return None;
         }
@@ -489,7 +498,8 @@ fn valid_date(s: &str) -> bool {
 /// A copy of the presentation with every slide pointing at a layout that exists.
 fn sanitized(p: &Presentation) -> std::borrow::Cow<'_, Presentation> {
     let mut need = p.masters.is_empty() || p.masters.iter().any(|m| m.layouts.is_empty());
-    need |= p.slides.iter().any(|s| p.layout(s.layout).is_none());
+    let layouts: std::collections::HashSet<_> = p.masters.iter().flat_map(|m| m.layouts.iter().map(|l| l.id)).collect();
+    need |= p.slides.iter().any(|s| !layouts.contains(&s.layout));
     if !need {
         return std::borrow::Cow::Borrowed(p);
     }
@@ -532,6 +542,13 @@ pub fn export(p: &Presentation, main_ct: &str) -> Result<Vec<u8>, PptxError> {
         p,
         pkg: PackageOut::default(),
         media_parts: HashMap::new(),
+        media_at: {
+            let mut m = HashMap::new();
+            for (i, item) in p.media.iter().enumerate() {
+                m.entry(item.id).or_insert(i);
+            }
+            m
+        },
         n_image: 0,
         n_media: 0,
         n_chart: 0,
@@ -541,6 +558,7 @@ pub fn export(p: &Presentation, main_ct: &str) -> Result<Vec<u8>, PptxError> {
         n_kept: 0,
         slide_parts: HashMap::new(),
         table_styles: vec![],
+        table_style_set: Default::default(),
         placeholder: None,
     };
     for (i, s) in p.slides.iter().enumerate() {
@@ -959,9 +977,16 @@ fn section_slides(p: &Presentation) -> Vec<(String, Vec<usize>)> {
     if out.is_empty() {
         return out;
     }
+    // Each slide's first section, found once: a section may name a slide many times.
+    let mut first: HashMap<SlideId, usize> = HashMap::new();
+    for (k, sec) in p.sections.iter().enumerate() {
+        for id in &sec.slides {
+            first.entry(*id).or_insert(k);
+        }
+    }
     let mut cur = 0usize;
     for (i, s) in p.slides.iter().enumerate() {
-        if let Some(k) = p.sections.iter().position(|sec| sec.slides.contains(&s.id))
+        if let Some(&k) = first.get(&s.id)
             && k >= cur
         {
             cur = k;
@@ -1027,7 +1052,7 @@ fn write_embedded_fonts(x: &mut Exp, o: &mut Out) -> Vec<WrittenFont> {
         if let Some(rid) = seen_part.get(&id) {
             return Some(rid.clone());
         }
-        let m = x.p.media(id)?;
+        let m = x.media(id)?;
         if m.data.is_empty() || m.data.len() > 32 * 1024 * 1024 {
             return None;
         }

crates/pptx/src/write/dml.rs

@@ -100,7 +100,7 @@ pub fn fill(w: &mut W, x: &mut Exp, o: &mut Out, f: &Fill) {
 pub fn blip_fill(w: &mut W, x: &mut Exp, o: &mut Out, tag: &str, pf: &PictureFill) {
     // An image that lives outside the package is a linked picture: `a:blip` names it through
     // `r:link`; `r:embed` may only reference a part inside the package.
-    let linked = x.p.media(pf.media).is_some_and(|m| m.data.is_empty() && m.link.is_some());
+    let linked = x.media(pf.media).is_some_and(|m| m.data.is_empty() && m.link.is_some());
     let rid = x.media_rel(o, pf.media, "image").unwrap_or_else(|| x.placeholder_rel(o));
     w.open(tag, A::new().a("rotWithShape", if pf.upright { "0" } else { "1" }));
     let adj = &pf.adjust;
@@ -441,7 +441,7 @@ pub fn hyperlink(w: &mut W, x: &mut Exp, o: &mut Out, tag: &str, h: &Hyperlink)
         return;
     };
     w.open(tag, attrs);
-    let name = x.p.media(sound_id).map(|m| sound_label(&m.name)).unwrap_or_else(|| "sound.wav".into());
+    let name = x.media(sound_id).map(|m| sound_label(&m.name)).unwrap_or_else(|| "sound.wav".into());
     w.empty("a:snd", A::new().a("r:embed", sound_rid).a("name", name));
     w.close(tag);
 }
@@ -587,7 +587,7 @@ pub fn ppr(w: &mut W, x: &mut Exp, o: &mut Out, tag: &str, level: Option<u8>, p:
         Some(Bullet::Picture { media }) => match x.media_rel(o, *media, "image") {
             Some(rid) => {
                 w.open0("a:buBlip");
-                let a = if x.p.media(*media).is_some_and(|m| m.data.is_empty() && m.link.is_some()) {
+                let a = if x.media(*media).is_some_and(|m| m.data.is_empty() && m.link.is_some()) {
                     A::new().a("r:link", &rid)
                 } else {
                     A::new().a("r:embed", &rid)

crates/pptx/src/write/shapes.rs

@@ -446,7 +446,7 @@ pub fn shape(w: &mut W, x: &mut Exp, o: &mut Out, cx: &mut Ctx, s: &Shape, depth
 }
 
 fn model_rel(x: &mut Exp, o: &mut Out, media: deckcraft_model::MediaId) -> Option<String> {
-    if x.p.media(media).is_none_or(|m| m.data.is_empty()) {
+    if x.media(media).is_none_or(|m| m.data.is_empty()) {
         return None;
     }
     x.media_rel(o, media, crate::opc::RT_MODEL3D)
@@ -479,7 +479,7 @@ fn write_model(
         return;
     };
     let id = cx.id_for(s);
-    let poster = poster.filter(|p| x.p.media(*p).is_some_and(|m| !m.data.is_empty()));
+    let poster = poster.filter(|p| x.media(*p).is_some_and(|m| !m.data.is_empty()));
     let Some(poster) = poster else {
         write_model_part(w, x, o, id, s, &rid);
         return;
@@ -700,7 +700,7 @@ fn table(w: &mut W, x: &mut Exp, o: &mut Out, t: &Table) {
     t.normalize();
     w.open0("a:tbl");
     let (guid, _) = crate::tables::guid_for_style(&t.style);
-    if !x.table_styles.contains(&t.style) {
+    if x.table_style_set.insert(t.style.clone()) {
         x.table_styles.push(t.style.clone());
     }
     w.open(
@@ -881,7 +881,7 @@ fn opaque(
         p.name = label.to_string();
     }
     match preview {
-        Some(m) if x.p.media(m).is_some() => {
+        Some(m) if x.media(m).is_some() => {
             p.kind = ShapeKind::Picture { fill: deckcraft_model::style::PictureFill { media: m, ..Default::default() } };
             p.ph = None;
             shape_with_id(w, x, o, cx, &p, id);

crates/pptx/src/write/timing.rs

@@ -16,7 +16,7 @@ pub fn transition(w: &mut W, x: &mut Exp, o: &mut Out, t: &Transition) {
         601..=900 => "med",
         _ => "slow",
     };
-    let sound = t.sound.and_then(|m| x.media_rel(o, m, "audio").map(|r| (r, x.p.media(m).map(|i| i.name.clone()).unwrap_or_default())));
+    let sound = t.sound.and_then(|m| x.media_rel(o, m, "audio").map(|r| (r, x.media(m).map(|i| i.name.clone()).unwrap_or_default())));
     let snd = |w: &mut W| {
         if let Some((r, name)) = &sound {
             w.open0("p:sndAc");

crates/pptx/tests/it/export_scale.rs

@@ -0,0 +1,31 @@
+//! Export looks media, layouts, sections and table styles up by id: a deck with many of each and
+//! many references to the last ones exports in time linear in its size.
+
+use std::sync::Arc;
+
+use deckcraft_model::style::PictureFill;
+use deckcraft_model::{Section, Shape, ShapeId, ShapeKind, defaults};
+
+#[test]
+fn many_media_sections_and_table_styles_export() {
+    let mut p = defaults::new_presentation(None);
+    // 5,000 media items; 5,000 pictures of the last one.
+    let mut last = None;
+    for i in 0..5_000u32 {
+        last = p.add_media(&format!("m{i}.png"), "image/png", i.to_le_bytes().to_vec());
+    }
+    let last = last.unwrap();
+    let pic = |k: u32| Shape {
+        id: ShapeId(100_000 + k),
+        kind: ShapeKind::Picture { fill: PictureFill { media: last, ..Default::default() } },
+        ..Default::default()
+    };
+    Arc::make_mut(&mut p.slides[0]).shapes = (0..5_000).map(pic).collect();
+    // A section naming the slide 50,000 times, after 2,000 empty sections.
+    let id = p.slides[0].id;
+    p.sections = (0..2_000).map(|i| Section { name: format!("s{i}"), slides: vec![] }).collect();
+    p.sections.push(Section { name: "last".into(), slides: vec![id; 50_000] });
+    let bytes = deckcraft_pptx::export(&p).expect("export");
+    let q = deckcraft_pptx::import(&bytes).expect("import");
+    assert_eq!(q.slides[0].shapes.iter().filter(|s| matches!(s.kind, ShapeKind::Picture { .. })).count(), 5_000);
+}

crates/pptx/tests/it/main.rs

@@ -9,6 +9,7 @@ mod corpus_kinds;
 mod corpus_media;
 mod corpus_style;
 mod corpus_themes;
+mod export_scale;
 mod fills;
 mod kept_parts;
 mod locks;