rpdfium_doc/

link_list.rs

//! Link annotation hit testing and link object introspection.
//!
//! Provides point-in-annotation testing for link annotations, supporting
//! both simple rectangle-based and QuadPoints-based hit detection.
//!
//! Also provides `LinkObject`, a typed view of a link annotation that
//! exposes quad-points, destination, and action — corresponding to
//! `FPDFLink_*` functions in PDFium's `fpdf_doc.h`.

use crate::action::Action;
use crate::annotation::{Annotation, AnnotationType};
use crate::destination::Destination;

/// A typed view of a link annotation for introspection.
///
/// Wraps a reference to an `Annotation` of subtype `Link` and provides
/// the upstream `FPDFLink_*` API surface: quad-point access, destination,
/// and action retrieval.
///
/// Obtain via [`find_link_at_position`] or [`collect_links`].
#[derive(Debug, Clone)]
pub struct LinkObject {
    /// Annotation rectangle `[x1, y1, x2, y2]`.
    pub rect: [f32; 4],
    /// QuadPoints (flat array of 8-float groups), if present.
    pub quad_points: Option<Vec<f32>>,
    /// The destination, if specified via `/Dest`.
    pub destination: Option<Destination>,
    /// The action, if specified via `/A`.
    pub action: Option<Action>,
    /// Index of this annotation in the page's annotation list.
    pub annotation_index: usize,
}

impl LinkObject {
    /// Build a `LinkObject` from a link `Annotation` at the given index.
    fn from_annotation(annot: &Annotation, index: usize) -> Self {
        Self {
            rect: annot.rect,
            quad_points: annot.subtype_data.quad_points.clone(),
            destination: annot.destination.clone(),
            action: annot.action.clone(),
            annotation_index: index,
        }
    }

    /// Returns the number of quad-point groups (quadrilaterals) on this link.
    ///
    /// Each group is 8 floats `[x1,y1, x2,y2, x3,y3, x4,y4]`.
    ///
    /// Corresponds to `FPDFLink_CountQuadPoints`.
    pub fn quad_point_count(&self) -> usize {
        self.quad_points.as_ref().map_or(0, |v| v.len() / 8)
    }

    /// ADR-019 alias for `quad_point_count()`.
    ///
    /// Corresponds to `FPDFLink_CountQuadPoints`.
    #[inline]
    pub fn link_count_quad_points(&self) -> usize {
        self.quad_point_count()
    }

    /// Deprecated: use [`link_count_quad_points()`](Self::link_count_quad_points)
    /// or [`quad_point_count()`](Self::quad_point_count) instead.
    #[deprecated(
        since = "0.1.0",
        note = "use link_count_quad_points() or quad_point_count() instead"
    )]
    #[inline]
    pub fn count_quad_points(&self) -> usize {
        self.quad_point_count()
    }

    /// Returns the `index`-th quad-point group as 8 floats, or `None` if
    /// the index is out of bounds.
    ///
    /// Corresponds to `FPDFLink_GetQuadPoints`.
    pub fn quad_points_at(&self, index: usize) -> Option<[f32; 8]> {
        let flat = self.quad_points.as_ref()?;
        let start = index * 8;
        if start + 8 > flat.len() {
            return None;
        }
        let s = &flat[start..start + 8];
        Some([s[0], s[1], s[2], s[3], s[4], s[5], s[6], s[7]])
    }

    /// Upstream-aligned alias for [`quad_points_at()`](Self::quad_points_at).
    ///
    /// Corresponds to `FPDFLink_GetQuadPoints`.
    #[inline]
    pub fn link_get_quad_points(&self, index: usize) -> Option<[f32; 8]> {
        self.quad_points_at(index)
    }

    /// Deprecated: use [`link_get_quad_points()`](Self::link_get_quad_points)
    /// or [`quad_points_at()`](Self::quad_points_at) instead.
    #[deprecated(
        since = "0.1.0",
        note = "use link_get_quad_points() or quad_points_at() instead"
    )]
    #[inline]
    pub fn get_quad_points(&self, index: usize) -> Option<[f32; 8]> {
        self.quad_points_at(index)
    }

    /// Deprecated: use [`link_get_quad_points()`](Self::link_get_quad_points)
    /// or [`quad_points_at()`](Self::quad_points_at) instead.
    #[deprecated(
        since = "0.1.0",
        note = "use link_get_quad_points() or quad_points_at() instead"
    )]
    #[inline]
    pub fn get_quad_points_at(&self, index: usize) -> Option<[f32; 8]> {
        self.quad_points_at(index)
    }

    /// Returns the link's destination, if any.
    ///
    /// Corresponds to `FPDFLink_GetDest`.
    pub fn dest(&self) -> Option<&Destination> {
        self.destination.as_ref()
    }

    /// ADR-019 alias for `dest()`.
    ///
    /// Corresponds to `FPDFLink_GetDest`.
    #[inline]
    pub fn link_get_dest(&self) -> Option<&Destination> {
        self.dest()
    }

    /// Deprecated: use [`link_get_dest()`](Self::link_get_dest)
    /// or [`dest()`](Self::dest) instead.
    #[deprecated(since = "0.1.0", note = "use link_get_dest() or dest() instead")]
    #[inline]
    pub fn get_dest(&self) -> Option<&Destination> {
        self.dest()
    }

    /// Returns the link's action, if any.
    ///
    /// Corresponds to `FPDFLink_GetAction`.
    pub fn action(&self) -> Option<&Action> {
        self.action.as_ref()
    }

    /// ADR-019 alias for `action()`.
    ///
    /// Corresponds to `FPDFLink_GetAction`.
    #[inline]
    pub fn link_get_action(&self) -> Option<&Action> {
        self.action()
    }

    /// Deprecated: use [`link_get_action()`](Self::link_get_action)
    /// or [`action()`](Self::action) instead.
    #[deprecated(since = "0.1.0", note = "use link_get_action() or action() instead")]
    #[inline]
    pub fn get_action(&self) -> Option<&Action> {
        self.action()
    }

    /// Returns the link's annotation rectangle.
    ///
    /// Corresponds to `FPDFLink_GetAnnotRect`.
    pub fn rect(&self) -> [f32; 4] {
        self.rect
    }

    /// ADR-019 alias for [`rect()`](Self::rect).
    ///
    /// Corresponds to `FPDFLink_GetAnnotRect`.
    #[inline]
    pub fn link_get_annot_rect(&self) -> [f32; 4] {
        self.rect()
    }

    /// Deprecated: use [`link_get_annot_rect()`](Self::link_get_annot_rect)
    /// or [`rect()`](Self::rect) instead.
    #[deprecated(since = "0.1.0", note = "use link_get_annot_rect() or rect() instead")]
    #[inline]
    pub fn get_annot_rect(&self) -> [f32; 4] {
        self.rect()
    }

    /// Returns the index of this link annotation in the page's annotation list.
    ///
    /// The caller can use this index to retrieve the full `Annotation` via
    /// `page.annotations()[link.annotation_index()]`.
    ///
    /// Corresponds to `FPDFLink_GetAnnot` — in PDFium this returns the
    /// annotation handle for a link; in rpdfium the equivalent is to look up
    /// the annotation by this index in the page's annotation slice.
    pub fn annotation_index(&self) -> usize {
        self.annotation_index
    }

    /// Upstream-aligned alias for [`annotation_index()`](Self::annotation_index).
    ///
    /// Corresponds to `FPDFLink_GetAnnot`.
    #[inline]
    pub fn link_get_annot(&self) -> usize {
        self.annotation_index()
    }

    /// Deprecated: use [`link_get_annot()`](Self::link_get_annot)
    /// or [`annotation_index()`](Self::annotation_index) instead.
    #[deprecated(
        since = "0.1.0",
        note = "use link_get_annot() or annotation_index() instead"
    )]
    #[inline]
    pub fn get_annot(&self) -> usize {
        self.annotation_index()
    }

    /// Deprecated: use [`link_get_annot()`](Self::link_get_annot)
    /// or [`annotation_index()`](Self::annotation_index) instead.
    #[deprecated(
        since = "0.1.0",
        note = "use link_get_annot() or annotation_index() instead"
    )]
    #[inline]
    pub fn get_annotation_index(&self) -> usize {
        self.annotation_index()
    }
}

/// Collect all link annotations from a page's annotation list.
///
/// Returns a `Vec<LinkObject>` containing only link-type annotations.
///
/// Corresponds to iterating links for `FPDFLink_Enumerate` usage.
pub fn collect_links(annotations: &[Annotation]) -> Vec<LinkObject> {
    annotations
        .iter()
        .enumerate()
        .filter(|(_, a)| a.subtype == AnnotationType::Link)
        .map(|(idx, a)| LinkObject::from_annotation(a, idx))
        .collect()
}

/// ADR-019 alias for [`collect_links`].
///
/// Corresponds to `FPDFLink_Enumerate`.
#[inline]
pub fn link_enumerate(annotations: &[Annotation]) -> Vec<LinkObject> {
    collect_links(annotations)
}

/// Deprecated: use [`link_enumerate()`] or [`collect_links()`] instead.
///
/// Corresponds to `FPDFLink_Enumerate`.
#[deprecated(
    since = "0.1.0",
    note = "use link_enumerate() or collect_links() instead"
)]
#[inline]
pub fn enumerate(annotations: &[Annotation]) -> Vec<LinkObject> {
    collect_links(annotations)
}

/// Deprecated: use [`link_enumerate()`] or [`collect_links()`] instead.
///
/// Corresponds to `FPDFLink_Enumerate`.
#[deprecated(
    since = "0.1.0",
    note = "use link_enumerate() or collect_links() instead"
)]
#[inline]
pub fn enumerate_links(annotations: &[Annotation]) -> Vec<LinkObject> {
    collect_links(annotations)
}

/// Find a link annotation at the given point and return it as a `LinkObject`.
///
/// Corresponds to `FPDFLink_GetLinkAtPoint`.
pub fn link_at_point(annotations: &[Annotation], x: f32, y: f32) -> Option<LinkObject> {
    for (idx, annot) in annotations.iter().enumerate() {
        if annot.subtype != AnnotationType::Link {
            continue;
        }

        let hit = if let Some(ref qp) = annot.subtype_data.quad_points {
            point_in_quad_points(qp, x, y)
        } else {
            point_in_rect(&annot.rect, x, y)
        };

        if hit {
            return Some(LinkObject::from_annotation(annot, idx));
        }
    }
    None
}

/// ADR-019 alias for [`link_at_point()`].
///
/// Corresponds to `FPDFLink_GetLinkAtPoint`.
#[inline]
pub fn link_get_link_at_point(annotations: &[Annotation], x: f32, y: f32) -> Option<LinkObject> {
    link_at_point(annotations, x, y)
}

/// Deprecated: use [`link_get_link_at_point()`] or [`link_at_point()`] instead.
///
/// Corresponds to `FPDFLink_GetLinkAtPoint`.
#[deprecated(
    since = "0.1.0",
    note = "use link_get_link_at_point() or link_at_point() instead"
)]
#[inline]
pub fn get_link_at_point(annotations: &[Annotation], x: f32, y: f32) -> Option<LinkObject> {
    link_at_point(annotations, x, y)
}

/// Result of a link hit test.
#[derive(Debug, Clone)]
pub struct HitTestResult {
    /// Index of the matching annotation in the annotations list.
    pub annotation_index: usize,
    /// The action associated with the link, if any.
    pub action: Option<Action>,
    /// The destination associated with the link, if any.
    pub destination: Option<Destination>,
    /// The URI if the action is a URI action.
    pub uri: Option<String>,
}

/// Find a link annotation at the given point.
///
/// Iterates over annotations, testing only those with `AnnotationType::Link`.
/// If the annotation has `/QuadPoints`, uses point-in-quadrilateral testing;
/// otherwise falls back to simple rectangle containment.
///
/// Returns the first matching link annotation.
pub fn find_link_at_position(annotations: &[Annotation], x: f32, y: f32) -> Option<HitTestResult> {
    for (idx, annot) in annotations.iter().enumerate() {
        if annot.subtype != AnnotationType::Link {
            continue;
        }

        let hit = if let Some(ref quad_points) = annot.subtype_data.quad_points {
            point_in_quad_points(quad_points, x, y)
        } else {
            point_in_rect(&annot.rect, x, y)
        };

        if hit {
            let uri = annot.action.as_ref().and_then(|a| {
                if let Action::Uri(u) = a {
                    Some(u.clone())
                } else {
                    None
                }
            });

            return Some(HitTestResult {
                annotation_index: idx,
                action: annot.action.clone(),
                destination: annot.destination.clone(),
                uri,
            });
        }
    }
    None
}

/// Test if a point is inside a rectangle `[x1, y1, x2, y2]`.
fn point_in_rect(rect: &[f32; 4], x: f32, y: f32) -> bool {
    let (x_min, x_max) = if rect[0] <= rect[2] {
        (rect[0], rect[2])
    } else {
        (rect[2], rect[0])
    };
    let (y_min, y_max) = if rect[1] <= rect[3] {
        (rect[1], rect[3])
    } else {
        (rect[3], rect[1])
    };
    x >= x_min && x <= x_max && y >= y_min && y <= y_max
}

/// Test if a point is inside any quadrilateral defined by QuadPoints.
///
/// QuadPoints are groups of 8 floats: `[x1,y1, x2,y2, x3,y3, x4,y4]`.
/// Each group defines one quadrilateral.
fn point_in_quad_points(quad_points: &[f32], x: f32, y: f32) -> bool {
    // Each quad is 8 floats (4 points)
    let mut offset = 0;
    while offset + 7 < quad_points.len() {
        let p0 = (quad_points[offset], quad_points[offset + 1]);
        let p1 = (quad_points[offset + 2], quad_points[offset + 3]);
        let p2 = (quad_points[offset + 4], quad_points[offset + 5]);
        let p3 = (quad_points[offset + 6], quad_points[offset + 7]);

        if point_in_quad(p0, p1, p2, p3, x, y) {
            return true;
        }
        offset += 8;
    }
    false
}

/// Test if a point is inside a convex quadrilateral using cross products.
///
/// For a convex quad (p0, p1, p2, p3), the point is inside if it is on the
/// same side of all four edges.
fn point_in_quad(
    p0: (f32, f32),
    p1: (f32, f32),
    p2: (f32, f32),
    p3: (f32, f32),
    x: f32,
    y: f32,
) -> bool {
    let edges = [(p0, p1), (p1, p2), (p2, p3), (p3, p0)];

    let mut pos = 0i32;
    let mut neg = 0i32;

    for &(a, b) in &edges {
        let cross = (b.0 - a.0) * (y - a.1) - (b.1 - a.1) * (x - a.0);
        if cross > 0.0 {
            pos += 1;
        } else if cross < 0.0 {
            neg += 1;
        }
    }

    // Point is inside if all cross products have the same sign (or are zero)
    pos == 0 || neg == 0
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::annotation::{AnnotationFlags, AnnotationSubtypeData};

    fn make_link(
        rect: [f32; 4],
        action: Option<Action>,
        quad_points: Option<Vec<f32>>,
    ) -> Annotation {
        Annotation {
            subtype: AnnotationType::Link,
            rect,
            contents: None,
            flags: AnnotationFlags::from_bits(0),
            name: None,
            appearance: None,
            color: None,
            border: None,
            action,
            destination: None,
            subtype_data: AnnotationSubtypeData {
                quad_points,
                ..Default::default()
            },
            mk: None,
            file_spec: None,
            parent_ref: None,
            object_id: None,
            open: None,
            ap_n_bytes: None,
            ap_r_bytes: None,
            ap_d_bytes: None,
            irt_ref: None,
            field_name: None,
            alternate_name: None,
            field_value: None,
            form_field_flags: None,
            additional_actions: None,
            form_field_type: None,
            options: None,
        }
    }

    fn make_text(rect: [f32; 4]) -> Annotation {
        Annotation {
            subtype: AnnotationType::Text,
            rect,
            contents: None,
            flags: AnnotationFlags::from_bits(0),
            name: None,
            appearance: None,
            color: None,
            border: None,
            action: None,
            destination: None,
            subtype_data: AnnotationSubtypeData::default(),
            mk: None,
            file_spec: None,
            parent_ref: None,
            object_id: None,
            open: None,
            ap_n_bytes: None,
            ap_r_bytes: None,
            ap_d_bytes: None,
            irt_ref: None,
            field_name: None,
            alternate_name: None,
            field_value: None,
            form_field_flags: None,
            additional_actions: None,
            form_field_type: None,
            options: None,
        }
    }

    #[test]
    fn test_hit_test_rect_inside() {
        let annotations = vec![make_link(
            [10.0, 10.0, 100.0, 30.0],
            Some(Action::Uri("https://example.com".into())),
            None,
        )];

        let result = find_link_at_position(&annotations, 50.0, 20.0).unwrap();
        assert_eq!(result.annotation_index, 0);
        assert_eq!(result.uri.as_deref(), Some("https://example.com"));
    }

    #[test]
    fn test_hit_test_rect_outside() {
        let annotations = vec![make_link(
            [10.0, 10.0, 100.0, 30.0],
            Some(Action::Uri("https://example.com".into())),
            None,
        )];

        assert!(find_link_at_position(&annotations, 5.0, 5.0).is_none());
    }

    #[test]
    fn test_hit_test_skips_non_link() {
        let annotations = vec![
            make_text([0.0, 0.0, 200.0, 200.0]),
            make_link(
                [10.0, 10.0, 100.0, 30.0],
                Some(Action::Uri("https://example.com".into())),
                None,
            ),
        ];

        let result = find_link_at_position(&annotations, 50.0, 20.0).unwrap();
        assert_eq!(result.annotation_index, 1);
    }

    #[test]
    fn test_hit_test_quad_points() {
        // A simple axis-aligned quad: (0,0) (100,0) (100,20) (0,20)
        let quad_points = vec![0.0, 0.0, 100.0, 0.0, 100.0, 20.0, 0.0, 20.0];
        let annotations = vec![make_link(
            [0.0, 0.0, 100.0, 20.0],
            Some(Action::Uri("https://example.com".into())),
            Some(quad_points),
        )];

        assert!(find_link_at_position(&annotations, 50.0, 10.0).is_some());
        assert!(find_link_at_position(&annotations, 150.0, 10.0).is_none());
    }

    #[test]
    fn test_hit_test_no_links_returns_none() {
        let annotations: Vec<Annotation> = Vec::new();
        assert!(find_link_at_position(&annotations, 50.0, 20.0).is_none());
    }

    #[test]
    fn test_hit_test_returns_first_match() {
        let annotations = vec![
            make_link(
                [0.0, 0.0, 100.0, 100.0],
                Some(Action::Uri("https://first.com".into())),
                None,
            ),
            make_link(
                [0.0, 0.0, 200.0, 200.0],
                Some(Action::Uri("https://second.com".into())),
                None,
            ),
        ];

        let result = find_link_at_position(&annotations, 50.0, 50.0).unwrap();
        assert_eq!(result.annotation_index, 0);
        assert_eq!(result.uri.as_deref(), Some("https://first.com"));
    }

    // -----------------------------------------------------------------------
    // LinkObject API tests
    // -----------------------------------------------------------------------

    #[test]
    fn test_link_at_point_returns_link_object() {
        let annotations = vec![make_link(
            [10.0, 10.0, 100.0, 30.0],
            Some(Action::Uri("https://example.com".into())),
            None,
        )];

        let link = link_at_point(&annotations, 50.0, 20.0).unwrap();
        assert_eq!(link.annotation_index, 0);
        assert_eq!(link.rect(), [10.0, 10.0, 100.0, 30.0]);
        match link.action() {
            Some(Action::Uri(u)) => assert_eq!(u, "https://example.com"),
            _ => panic!("expected URI action"),
        }
        assert!(link.dest().is_none());
    }

    #[test]
    fn test_link_at_point_miss_returns_none() {
        let annotations = vec![make_link(
            [10.0, 10.0, 100.0, 30.0],
            Some(Action::Uri("https://example.com".into())),
            None,
        )];

        assert!(link_at_point(&annotations, 200.0, 200.0).is_none());
    }

    #[test]
    fn test_link_at_point_with_quad_points() {
        let qp = vec![0.0, 0.0, 100.0, 0.0, 100.0, 20.0, 0.0, 20.0];
        let annotations = vec![make_link(
            [0.0, 0.0, 100.0, 20.0],
            Some(Action::Uri("https://example.com".into())),
            Some(qp),
        )];

        let link = link_at_point(&annotations, 50.0, 10.0).unwrap();
        assert_eq!(link.quad_point_count(), 1);
        assert_eq!(link.link_count_quad_points(), 1);
        let qp = link.quad_points_at(0).unwrap();
        assert_eq!(qp[0], 0.0);
        assert_eq!(qp[2], 100.0);
        assert!(link.quad_points_at(1).is_none());
    }

    #[test]
    fn test_link_object_quad_points_multiple_groups() {
        let qp = vec![
            0.0, 0.0, 10.0, 0.0, 10.0, 10.0, 0.0, 10.0, // group 0
            20.0, 20.0, 30.0, 20.0, 30.0, 30.0, 20.0, 30.0, // group 1
        ];
        let link = LinkObject {
            rect: [0.0, 0.0, 30.0, 30.0],
            quad_points: Some(qp),
            destination: None,
            action: None,
            annotation_index: 0,
        };
        assert_eq!(link.quad_point_count(), 2);
        let g0 = link.link_get_quad_points(0).unwrap();
        assert_eq!(g0[0], 0.0);
        let g1 = link.link_get_quad_points(1).unwrap();
        assert_eq!(g1[0], 20.0);
        assert!(link.link_get_quad_points(2).is_none());
    }

    #[test]
    fn test_link_object_no_quad_points() {
        let link = LinkObject {
            rect: [0.0, 0.0, 100.0, 50.0],
            quad_points: None,
            destination: None,
            action: None,
            annotation_index: 0,
        };
        assert_eq!(link.quad_point_count(), 0);
        assert!(link.quad_points_at(0).is_none());
    }

    #[test]
    fn test_collect_links_filters_link_annotations() {
        let annotations = vec![
            make_text([0.0, 0.0, 100.0, 100.0]),
            make_link(
                [10.0, 10.0, 50.0, 20.0],
                Some(Action::Uri("https://a.com".into())),
                None,
            ),
            make_text([200.0, 200.0, 300.0, 300.0]),
            make_link(
                [60.0, 60.0, 90.0, 80.0],
                Some(Action::Uri("https://b.com".into())),
                None,
            ),
        ];

        let links = collect_links(&annotations);
        assert_eq!(links.len(), 2);
        assert_eq!(links[0].annotation_index, 1);
        assert_eq!(links[1].annotation_index, 3);
    }

    #[test]
    fn test_link_get_link_at_point_alias_works() {
        let annotations = vec![make_link(
            [0.0, 0.0, 100.0, 100.0],
            Some(Action::Uri("https://example.com".into())),
            None,
        )];

        let link = link_get_link_at_point(&annotations, 50.0, 50.0).unwrap();
        assert_eq!(link.annotation_index, 0);
    }

    #[test]
    fn test_link_object_dest_accessor() {
        use crate::destination::{Destination, PageFit};
        let link = LinkObject {
            rect: [0.0, 0.0, 100.0, 50.0],
            quad_points: None,
            destination: Some(Destination::Page {
                page_index: 3,
                page_ref: None,
                fit: PageFit::Fit,
            }),
            action: None,
            annotation_index: 0,
        };
        assert!(link.dest().is_some());
        assert!(link.link_get_dest().is_some());
        assert!(link.action().is_none());
        assert!(link.link_get_action().is_none());
    }

    // -----------------------------------------------------------------------
    // annotation_index / get_annot — FPDFLink_GetAnnot equivalent
    // -----------------------------------------------------------------------

    #[test]
    fn test_annotation_index_returns_correct_index() {
        // Build a page with two annotations: one Text (idx 0) and one Link (idx 1).
        let annotations = vec![
            make_text([0.0, 0.0, 100.0, 100.0]),
            make_link(
                [10.0, 10.0, 90.0, 30.0],
                Some(Action::Uri("https://example.com".into())),
                None,
            ),
        ];

        let links = collect_links(&annotations);
        assert_eq!(links.len(), 1);

        let link = &links[0];
        // The link is the second annotation (index 1).
        assert_eq!(link.annotation_index(), 1);
        assert_eq!(link.link_get_annot(), 1);
    }

    #[test]
    fn test_annotation_index_matches_link_at_point() {
        // Two links at different positions.
        let annotations = vec![
            make_link(
                [0.0, 0.0, 50.0, 50.0],
                Some(Action::Uri("https://first.com".into())),
                None,
            ),
            make_link(
                [100.0, 100.0, 200.0, 150.0],
                Some(Action::Uri("https://second.com".into())),
                None,
            ),
        ];

        let link0 = link_at_point(&annotations, 25.0, 25.0).unwrap();
        let link1 = link_at_point(&annotations, 150.0, 125.0).unwrap();

        assert_eq!(link0.annotation_index(), 0);
        assert_eq!(link0.link_get_annot(), 0);
        assert_eq!(link1.annotation_index(), 1);
        assert_eq!(link1.link_get_annot(), 1);
    }
}