Fix clipping with outset (#5295)

Co-authored-by: Laurenz <laurmaedje@gmail.com>

crates/typst-layout/src/flow/block.rs

@@ -84,8 +84,7 @@ pub fn layout_single_block(
 
     // Clip the contents, if requested.
     if elem.clip(styles) {
-        let size = frame.size() + outset.relative_to(frame.size()).sum_by_axis();
-        frame.clip(clip_rect(size, &radius, &stroke));
+        frame.clip(clip_rect(frame.size(), &radius, &stroke, &outset));
     }
 
     // Add fill and/or stroke.
@@ -231,8 +230,7 @@ pub fn layout_multi_block(
 
         // Clip the contents, if requested.
         if clip {
-            let size = frame.size() + outset.relative_to(frame.size()).sum_by_axis();
-            frame.clip(clip_rect(size, &radius, &stroke));
+            frame.clip(clip_rect(frame.size(), &radius, &stroke, &outset));
         }
 
         // Add fill and/or stroke.

crates/typst-layout/src/inline/box.rs

@@ -61,8 +61,7 @@ pub fn layout_box(
 
     // Clip the contents, if requested.
     if elem.clip(styles) {
-        let size = frame.size() + outset.relative_to(frame.size()).sum_by_axis();
-        frame.clip(clip_rect(size, &radius, &stroke));
+        frame.clip(clip_rect(frame.size(), &radius, &stroke, &outset));
     }
 
     // Add fill and/or stroke.

crates/typst-layout/src/shapes.rs

@@ -412,7 +412,11 @@ pub fn clip_rect(
     size: Size,
     radius: &Corners<Rel<Abs>>,
     stroke: &Sides<Option<FixedStroke>>,
+    outset: &Sides<Rel<Abs>>,
 ) -> Path {
+    let outset = outset.relative_to(size);
+    let size = size + outset.sum_by_axis();
+
     let stroke_widths = stroke
         .as_ref()
         .map(|s| s.as_ref().map_or(Abs::zero(), |s| s.thickness / 2.0));
@@ -441,6 +445,7 @@ pub fn clip_rect(
         }
     }
     path.close_path();
+    path.translate(Point::new(-outset.left, -outset.top));
     path
 }
 

crates/typst-library/src/visualize/path.rs

@@ -1,4 +1,5 @@
 use kurbo::ParamCurveExtrema;
+use typst_utils::Numeric;
 
 use self::PathVertex::{AllControlPoints, MirroredControlPoint, Vertex};
 use crate::diag::{bail, SourceResult};
@@ -228,6 +229,25 @@ impl Path {
         self.0.push(PathItem::ClosePath);
     }
 
+    /// Translate all points in this path by the given offset.
+    pub fn translate(&mut self, offset: Point) {
+        if offset.is_zero() {
+            return;
+        }
+        for item in self.0.iter_mut() {
+            match item {
+                PathItem::MoveTo(p) => *p += offset,
+                PathItem::LineTo(p) => *p += offset,
+                PathItem::CubicTo(p1, p2, p3) => {
+                    *p1 += offset;
+                    *p2 += offset;
+                    *p3 += offset;
+                }
+                PathItem::ClosePath => (),
+            }
+        }
+    }
+
     /// Computes the size of bounding box of this path.
     pub fn bbox_size(&self) -> Size {
         let mut min_x = Abs::inf();

tests/suite/layout/container.typ

@@ -251,6 +251,19 @@ First!
   image("/assets/images/rhino.png", width: 30pt)
 )
 
+--- box-clip-outset ---
+// Test clipping with `outset`.
+#set page(height: 60pt)
+
+#box(
+  outset: 5pt,
+  stroke: 2pt + black,
+  width: 20pt,
+  height: 20pt,
+  clip: true,
+  image("/assets/images/rhino.png", width: 30pt)
+)
+
 --- container-layoutable-child ---
 // Test box/block sizing with directly layoutable child.
 //