diff --git a/topola/src/primitives.rs b/topola/src/primitives.rs
deleted file mode 100644
index 87387a5..0000000
--- a/topola/src/primitives.rs
+++ /dev/null
@@ -1,205 +0,0 @@
-// SPDX-FileCopyrightText: 2026 Topola contributors
-//
-// SPDX-License-Identifier: MIT OR Apache-2.0
-
-use derive_more::Constructor;
-use rstar::{AABB, Envelope, primitives::Rectangle};
-use serde::{Deserialize, Serialize};
-
-use crate::{
-    Vector2,
-    layout::{NetId, PinId},
-};
-
-#[derive(Clone, Copy, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize)]
-pub enum PrimitiveId {
-    Joint(JointId),
-    Segment(SegmentId),
-    Polygon(PolygonId),
-}
-
-#[derive(
-    Clone, Constructor, Copy, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize,
-)]
-pub struct JointId(usize);
-
-impl JointId {
-    /// Returns the underlying index.
-    #[inline]
-    pub fn index(self) -> usize {
-        self.0
-    }
-}
-
-#[derive(Clone, Copy, Debug)]
-pub struct Joint {
-    pub position: Vector2<i64>,
-    pub layer: usize,
-    pub radius: u64,
-    pub net: NetId,
-    pub pin: Option<PinId>,
-}
-
-impl Joint {
-    pub fn bbox(&self) -> Rectangle<[i64; 3]> {
-        Rectangle::from_aabb(AABB::from_corners(
-            [
-                self.position.x - self.radius as i64,
-                self.position.y - self.radius as i64,
-                self.layer as i64,
-            ],
-            [
-                self.position.x + self.radius as i64,
-                self.position.y + self.radius as i64,
-                self.layer as i64,
-            ],
-        ))
-    }
-
-    pub fn center(&self) -> Vector2<i64> {
-        self.position
-    }
-
-    pub fn contains_point(&self, point: Vector2<i64>) -> bool {
-        (point.x - self.position.x).pow(2) as u64 + (point.y - self.position.y).pow(2) as u64
-            <= self.radius.pow(2)
-    }
-}
-
-#[derive(
-    Clone, Constructor, Copy, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize,
-)]
-pub struct SegmentId(usize);
-
-impl SegmentId {
-    /// Returns the underlying index.
-    #[inline]
-    pub fn index(self) -> usize {
-        self.0
-    }
-}
-
-#[derive(Clone, Copy, Debug)]
-pub struct SegmentSpec {
-    pub endjoints: [JointId; 2],
-    pub half_width: u64,
-    pub pin: Option<PinId>,
-}
-
-#[derive(Clone, Copy, Debug)]
-pub struct Segment {
-    pub spec: SegmentSpec,
-    pub endpoints: [Vector2<i64>; 2],
-    pub layer: usize,
-    pub net: NetId,
-}
-
-impl Segment {
-    pub fn center(&self) -> Vector2<i64> {
-        (self.endpoints[0] + self.endpoints[1]) / 2
-    }
-
-    pub fn contains_point(&self, point: Vector2<i64>) -> bool {
-        let vertices = crate::math::inflated_segment(
-            self.endpoints[0].x,
-            self.endpoints[0].y,
-            self.endpoints[1].x,
-            self.endpoints[1].y,
-            self.spec.half_width,
-        );
-        point.inside_polygon(&vertices)
-    }
-
-    pub fn bbox(&self) -> [Vector2<i64>; 4] {
-        crate::math::inflated_segment(
-            self.endpoints[0].x,
-            self.endpoints[0].y,
-            self.endpoints[1].x,
-            self.endpoints[1].y,
-            self.spec.half_width,
-        )
-    }
-
-    pub fn rtree_bbox(&self) -> Rectangle<[i64; 3]> {
-        let endpoints = self.endpoints;
-        let layer = self.layer as i64;
-        let half_width = self.spec.half_width as i64;
-
-        let min_x = std::cmp::min(endpoints[0].x, endpoints[1].x) - half_width;
-        let min_y = std::cmp::min(endpoints[0].y, endpoints[1].y) - half_width;
-        let max_x = std::cmp::max(endpoints[0].x, endpoints[1].x) + half_width;
-        let max_y = std::cmp::max(endpoints[0].y, endpoints[1].y) + half_width;
-
-        Rectangle::from_corners([min_x, min_y, layer], [max_x, max_y, layer])
-    }
-}
-
-#[derive(
-    Clone, Constructor, Copy, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize,
-)]
-pub struct ViaId(usize);
-
-impl ViaId {
-    /// Returns the underlying index.
-    #[inline]
-    pub fn index(self) -> usize {
-        self.0
-    }
-}
-
-#[derive(Clone, Copy, Debug)]
-pub struct Via {
-    pub endjoints: [JointId; 2],
-    pub layer: usize, // ??? This should be a range.
-    pub radius: u64,
-    pub net: NetId,
-    pub pin: Option<PinId>,
-}
-
-impl Via {
-    /*pub fn bbox(&self) -> Rectangle<[i64; 3]> {
-        //
-    }*/
-}
-
-#[derive(
-    Clone, Constructor, Copy, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize,
-)]
-pub struct PolygonId(usize);
-
-impl PolygonId {
-    /// Returns the underlying index.
-    #[inline]
-    pub fn index(self) -> usize {
-        self.0
-    }
-}
-
-#[derive(Clone, Debug)]
-pub struct Polygon {
-    pub vertices: Vec<Vector2<i64>>,
-    pub layer: usize,
-    pub net: NetId,
-    pub pin: Option<PinId>,
-}
-
-impl Polygon {
-    pub fn bbox(&self) -> Rectangle<[i64; 3]> {
-        Rectangle::from_aabb(
-            self.vertices
-                .clone()
-                .into_iter()
-                .fold(AABB::new_empty(), |aabb, vertex| {
-                    aabb.merged(&AABB::from_point([vertex.x, vertex.y, self.layer as i64]))
-                }),
-        )
-    }
-
-    pub fn center(&self) -> Vector2<i64> {
-        Vector2::<i64>::polygon_centroid(&self.vertices)
-    }
-
-    pub fn contains_point(&self, point: Vector2<i64>) -> bool {
-        point.inside_polygon(&self.vertices)
-    }
-}
diff --git a/topola/src/primitives/joint.rs b/topola/src/primitives/joint.rs
new file mode 100644
index 0000000..1b022fb
--- /dev/null
+++ b/topola/src/primitives/joint.rs
@@ -0,0 +1,58 @@
+// SPDX-FileCopyrightText: 2026 Topola contributors
+//
+// SPDX-License-Identifier: MIT OR Apache-2.0
+
+use derive_more::Constructor;
+use rstar::{AABB, primitives::Rectangle};
+use serde::{Deserialize, Serialize};
+
+use crate::layout::{NetId, PinId};
+use crate::math::Vector2;
+
+#[derive(
+    Clone, Constructor, Copy, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize,
+)]
+pub struct JointId(usize);
+
+impl JointId {
+    /// Returns the underlying index.
+    #[inline]
+    pub fn index(self) -> usize {
+        self.0
+    }
+}
+
+#[derive(Clone, Copy, Debug)]
+pub struct Joint {
+    pub position: Vector2<i64>,
+    pub layer: usize,
+    pub radius: u64,
+    pub net: NetId,
+    pub pin: Option<PinId>,
+}
+
+impl Joint {
+    pub fn bbox(&self) -> Rectangle<[i64; 3]> {
+        Rectangle::from_aabb(AABB::from_corners(
+            [
+                self.position.x - self.radius as i64,
+                self.position.y - self.radius as i64,
+                self.layer as i64,
+            ],
+            [
+                self.position.x + self.radius as i64,
+                self.position.y + self.radius as i64,
+                self.layer as i64,
+            ],
+        ))
+    }
+
+    pub fn center(&self) -> Vector2<i64> {
+        self.position
+    }
+
+    pub fn contains_point(&self, point: Vector2<i64>) -> bool {
+        (point.x - self.position.x).pow(2) as u64 + (point.y - self.position.y).pow(2) as u64
+            <= self.radius.pow(2)
+    }
+}
diff --git a/topola/src/primitives/mod.rs b/topola/src/primitives/mod.rs
new file mode 100644
index 0000000..6eef915
--- /dev/null
+++ b/topola/src/primitives/mod.rs
@@ -0,0 +1,22 @@
+// SPDX-FileCopyrightText: 2026 Topola contributors
+//
+// SPDX-License-Identifier: MIT OR Apache-2.0
+
+use serde::{Deserialize, Serialize};
+
+mod joint;
+mod polygon;
+mod segment;
+mod via;
+
+pub use joint::{Joint, JointId};
+pub use polygon::{Polygon, PolygonId};
+pub use segment::{Segment, SegmentId, SegmentSpec};
+pub use via::{Via, ViaId};
+
+#[derive(Clone, Copy, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize)]
+pub enum PrimitiveId {
+    Joint(JointId),
+    Segment(SegmentId),
+    Polygon(PolygonId),
+}
diff --git a/topola/src/primitives/polygon.rs b/topola/src/primitives/polygon.rs
new file mode 100644
index 0000000..905180b
--- /dev/null
+++ b/topola/src/primitives/polygon.rs
@@ -0,0 +1,52 @@
+// SPDX-FileCopyrightText: 2026 Topola contributors
+//
+// SPDX-License-Identifier: MIT OR Apache-2.0
+
+use derive_more::Constructor;
+use rstar::{AABB, Envelope, primitives::Rectangle};
+use serde::{Deserialize, Serialize};
+
+use crate::layout::{NetId, PinId};
+use crate::math::Vector2;
+
+#[derive(
+    Clone, Constructor, Copy, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize,
+)]
+pub struct PolygonId(usize);
+
+impl PolygonId {
+    /// Returns the underlying index.
+    #[inline]
+    pub fn index(self) -> usize {
+        self.0
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct Polygon {
+    pub vertices: Vec<Vector2<i64>>,
+    pub layer: usize,
+    pub net: NetId,
+    pub pin: Option<PinId>,
+}
+
+impl Polygon {
+    pub fn bbox(&self) -> Rectangle<[i64; 3]> {
+        Rectangle::from_aabb(
+            self.vertices
+                .clone()
+                .into_iter()
+                .fold(AABB::new_empty(), |aabb, vertex| {
+                    aabb.merged(&AABB::from_point([vertex.x, vertex.y, self.layer as i64]))
+                }),
+        )
+    }
+
+    pub fn center(&self) -> Vector2<i64> {
+        Vector2::<i64>::polygon_centroid(&self.vertices)
+    }
+
+    pub fn contains_point(&self, point: Vector2<i64>) -> bool {
+        point.inside_polygon(&self.vertices)
+    }
+}
diff --git a/topola/src/primitives/segment.rs b/topola/src/primitives/segment.rs
new file mode 100644
index 0000000..4b1c711
--- /dev/null
+++ b/topola/src/primitives/segment.rs
@@ -0,0 +1,79 @@
+// SPDX-FileCopyrightText: 2026 Topola contributors
+//
+// SPDX-License-Identifier: MIT OR Apache-2.0
+
+use derive_more::Constructor;
+use rstar::primitives::Rectangle;
+use serde::{Deserialize, Serialize};
+
+use crate::layout::{NetId, PinId};
+use crate::math::Vector2;
+use crate::primitives::JointId;
+
+#[derive(
+    Clone, Constructor, Copy, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize,
+)]
+pub struct SegmentId(usize);
+
+impl SegmentId {
+    /// Returns the underlying index.
+    #[inline]
+    pub fn index(self) -> usize {
+        self.0
+    }
+}
+
+#[derive(Clone, Copy, Debug)]
+pub struct SegmentSpec {
+    pub endjoints: [JointId; 2],
+    pub half_width: u64,
+    pub pin: Option<PinId>,
+}
+
+#[derive(Clone, Copy, Debug)]
+pub struct Segment {
+    pub spec: SegmentSpec,
+    pub endpoints: [Vector2<i64>; 2],
+    pub layer: usize,
+    pub net: NetId,
+}
+
+impl Segment {
+    pub fn center(&self) -> Vector2<i64> {
+        (self.endpoints[0] + self.endpoints[1]) / 2
+    }
+
+    pub fn contains_point(&self, point: Vector2<i64>) -> bool {
+        let vertices = crate::math::inflated_segment(
+            self.endpoints[0].x,
+            self.endpoints[0].y,
+            self.endpoints[1].x,
+            self.endpoints[1].y,
+            self.spec.half_width,
+        );
+        point.inside_polygon(&vertices)
+    }
+
+    pub fn bbox(&self) -> [Vector2<i64>; 4] {
+        crate::math::inflated_segment(
+            self.endpoints[0].x,
+            self.endpoints[0].y,
+            self.endpoints[1].x,
+            self.endpoints[1].y,
+            self.spec.half_width,
+        )
+    }
+
+    pub fn rtree_bbox(&self) -> Rectangle<[i64; 3]> {
+        let endpoints = self.endpoints;
+        let layer = self.layer as i64;
+        let half_width = self.spec.half_width as i64;
+
+        let min_x = std::cmp::min(endpoints[0].x, endpoints[1].x) - half_width;
+        let min_y = std::cmp::min(endpoints[0].y, endpoints[1].y) - half_width;
+        let max_x = std::cmp::max(endpoints[0].x, endpoints[1].x) + half_width;
+        let max_y = std::cmp::max(endpoints[0].y, endpoints[1].y) + half_width;
+
+        Rectangle::from_corners([min_x, min_y, layer], [max_x, max_y, layer])
+    }
+}
diff --git a/topola/src/primitives/via.rs b/topola/src/primitives/via.rs
new file mode 100644
index 0000000..3c4387c
--- /dev/null
+++ b/topola/src/primitives/via.rs
@@ -0,0 +1,38 @@
+// SPDX-FileCopyrightText: 2026 Topola contributors
+//
+// SPDX-License-Identifier: MIT OR Apache-2.0
+
+use derive_more::Constructor;
+use serde::{Deserialize, Serialize};
+
+use crate::layout::{NetId, PinId};
+
+use super::joint::JointId;
+
+#[derive(
+    Clone, Constructor, Copy, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize,
+)]
+pub struct ViaId(usize);
+
+impl ViaId {
+    /// Returns the underlying index.
+    #[inline]
+    pub fn index(self) -> usize {
+        self.0
+    }
+}
+
+#[derive(Clone, Copy, Debug)]
+pub struct Via {
+    pub endjoints: [JointId; 2],
+    pub layer: usize, // ??? This should be a range.
+    pub radius: u64,
+    pub net: NetId,
+    pub pin: Option<PinId>,
+}
+
+impl Via {
+    /*pub fn bbox(&self) -> Rectangle<[i64; 3]> {
+        //
+    }*/
+}