fix: only use link annotation quadpoints when exporting a PDF/UA-1 document

crates/typst-pdf/src/convert.rs

@@ -171,14 +171,14 @@ impl State {
 /// Context needed for converting a single frame.
 pub(crate) struct FrameContext {
     states: Vec<State>,
-    pub(crate) link_annotations: HashMap<tags::LinkId, LinkAnnotation>,
+    link_annotations: Vec<LinkAnnotation>,
 }
 
 impl FrameContext {
     pub(crate) fn new(size: Size) -> Self {
         Self {
             states: vec![State::new(size)],
-            link_annotations: HashMap::new(),
+            link_annotations: Vec::new(),
         }
     }
 
@@ -197,6 +197,20 @@ impl FrameContext {
     pub(crate) fn state_mut(&mut self) -> &mut State {
         self.states.last_mut().unwrap()
     }
+
+    pub(crate) fn get_link_annotation(
+        &mut self,
+        link_id: tags::LinkId,
+    ) -> Option<&mut LinkAnnotation> {
+        self.link_annotations
+            .iter_mut()
+            .rev()
+            .find(|annot| annot.id == link_id)
+    }
+
+    pub(crate) fn push_link_annotation(&mut self, annotation: LinkAnnotation) {
+        self.link_annotations.push(annotation);
+    }
 }
 
 /// Globally needed context for converting a typst document.

crates/typst-pdf/src/link.rs

@@ -1,18 +1,18 @@
-use std::collections::hash_map::Entry;
-
 use ecow::EcoString;
 use krilla::action::{Action, LinkAction};
 use krilla::annotation::Target;
+use krilla::configure::Validator;
 use krilla::destination::XyzDestination;
 use krilla::geom as kg;
 use typst_library::layout::{Abs, Point, Position, Size};
 use typst_library::model::Destination;
 
 use crate::convert::{FrameContext, GlobalContext};
-use crate::tags::{Placeholder, StackEntryKind, TagNode};
+use crate::tags::{self, Placeholder, StackEntryKind, TagNode};
 use crate::util::{AbsExt, PointExt};
 
 pub(crate) struct LinkAnnotation {
+    pub(crate) id: tags::LinkId,
     pub(crate) placeholder: Placeholder,
     pub(crate) alt: Option<String>,
     pub(crate) rect: kg::Rect,
@@ -50,7 +50,7 @@ pub(crate) fn handle_link(
     };
 
     let entry = gc.tags.stack.last_mut().expect("a link parent");
-    let StackEntryKind::Link(link_id, link) = &entry.kind else {
+    let StackEntryKind::Link(link_id, ref link) = entry.kind else {
         unreachable!("expected a link parent")
     };
     let alt = link.alt.as_ref().map(EcoString::to_string);
@@ -58,18 +58,21 @@ pub(crate) fn handle_link(
     let rect = to_rect(fc, size);
     let quadpoints = quadpoints(rect);
 
-    match fc.link_annotations.entry(*link_id) {
+    // Unfortunately quadpoints still aren't well supported by most PDF readers,
-        Entry::Occupied(occupied) => {
+    // even by acrobat. Which is understandable since they were only introduced
-            // Update the bounding box and add the quadpoints of an existing link annotation.
+    // in PDF 1.6 (2005) /s
-            let annotation = occupied.into_mut();
+    let should_use_quadpoints = gc.options.standards.config.validator() == Validator::UA1;
+    match fc.get_link_annotation(link_id) {
+        Some(annotation) if should_use_quadpoints => {
+            // Update the bounding box and add the quadpoints to an existing link annotation.
             annotation.rect = bounding_rect(annotation.rect, rect);
             annotation.quad_points.extend_from_slice(&quadpoints);
         }
-        Entry::Vacant(vacant) => {
+        _ => {
             let placeholder = gc.tags.reserve_placeholder();
             gc.tags.push(TagNode::Placeholder(placeholder));
-
+            fc.push_link_annotation(LinkAnnotation {
-            vacant.insert(LinkAnnotation {
+                id: link_id,
                 placeholder,
                 rect,
                 quad_points: quadpoints.to_vec(),

crates/typst-pdf/src/tags.rs

@@ -1,5 +1,4 @@
 use std::cell::OnceCell;
-use std::collections::HashMap;
 
 use ecow::EcoString;
 use krilla::page::Page;
@@ -335,10 +334,11 @@ fn start_content<'a, 'b>(
 pub(crate) fn add_annotations(
     gc: &mut GlobalContext,
     page: &mut Page,
-    annotations: HashMap<LinkId, LinkAnnotation>,
+    annotations: Vec<LinkAnnotation>,
 ) {
-    for annotation in annotations.into_values() {
+    for annotation in annotations.into_iter() {
-        let LinkAnnotation { placeholder, alt, rect, quad_points, target } = annotation;
+        let LinkAnnotation { id: _, placeholder, alt, rect, quad_points, target } =
+            annotation;
         let annot = krilla::annotation::Annotation::new_link(
             krilla::annotation::LinkAnnotation::new(rect, Some(quad_points), target),
             alt,