diff -r a4c17cfaa4c9 -r abbb74b9cb62 rust/hwphysics/src/lib.rs
--- a/rust/hwphysics/src/lib.rs	Fri Nov 09 01:05:34 2018 +0300
+++ b/rust/hwphysics/src/lib.rs	Fri Nov 09 03:36:21 2018 +0300
@@ -4,10 +4,16 @@
 mod collision;
 
 use fpnum::FPNum;
+use integral_geometry::Size;
 use land2d::Land2D;
 
 use crate::{
-    common::GearId,
+    common::{
+        GearId,
+        GearData,
+        GearDataAggregator,
+        GearDataProcessor
+    },
     physics::{
         PhysicsProcessor,
         PhysicsData
@@ -31,19 +37,72 @@
     collision: CollisionProcessor,
 }
 
+macro_rules! processor_map {
+    ( $data_type: ident => $field: ident ) => {
+        impl GearDataAggregator<$data_type> for World {
+            fn find_processor(&mut self) -> &mut GearDataProcessor<$data_type> {
+                &mut self.$field
+            }
+        }
+    }
+}
+
+processor_map!(PhysicsData => physics);
+processor_map!(CollisionData => collision);
+
 impl World {
+    pub fn new(world_size: Size) -> Self {
+        Self {
+            physics: PhysicsProcessor::new(),
+            collision: CollisionProcessor::new(world_size)
+        }
+    }
+
     pub fn step(&mut self, time_step: FPNum, land: &Land2D<u32>) {
         let updates = self.physics.process(time_step);
         self.collision.process(land, &updates);
     }
 
-    pub fn add_gear(&mut self, data: JoinedData) {
-        self.physics.push(data.gear_id, data.physics);
-        self.collision.push(data.gear_id, data.physics, data.collision);
+    pub fn add_gear_data<T>(&mut self, gear_id: GearId, data: T)
+        where T: GearData,
+              Self: GearDataAggregator<T>
+    {
+        self.find_processor().add(gear_id, data);
     }
 }
 
 #[cfg(test)]
 mod tests {
+    use crate::{
+        World,
+        physics::PhysicsData,
+        collision::{CollisionData, CircleBounds}
+    };
+    use fpnum::{FPNum, FPPoint, fp};
+    use integral_geometry::Size;
+    use land2d::Land2D;
 
+    #[test]
+    fn data_flow() {
+        let world_size = Size::new(2048, 2048);
+
+        let mut world = World::new(world_size);
+        let gear_id = 46631;
+
+        world.add_gear_data(gear_id, PhysicsData {
+            position: FPPoint::zero(),
+            velocity: FPPoint::unit_y()
+        });
+
+        world.add_gear_data(gear_id, CollisionData {
+            bounds: CircleBounds {
+                center: FPPoint::zero(),
+                radius: fp!(10)
+            }
+        });
+
+        let land = Land2D::new(Size::new(world_size.width - 2, world_size.height - 2), 0);
+
+        world.step(fp!(1), &land);
+    }
 }