Add rigidBody.velocityAtPoint (#305)

* Add rigidBody.velocityAtPoint

* Add changelog entry

* fix: free wasm vector in RigidBody.velocityAtPoint.

---------

Co-authored-by: Sébastien Crozet <[email protected]>

Author: alexandernanberg

CHANGELOG.md

@@ -30,6 +30,10 @@
 
 
 
+#### Added
+
+- Added `RigidBody.velocityAtPoint` function to retrieve the velocity of a given world-space point on a rigid-body.
+
 ### 0.14.0 (20 July 2024)
 
 #### Modified

src.ts/dynamics/rigid_body.ts

@@ -507,6 +507,18 @@ export class RigidBody {
         return VectorOps.fromRaw(this.rawSet.rbLinvel(this.handle));
     }
 
+    /**
+     * The velocity of the given world-space point on this rigid-body.
+     */
+    public velocityAtPoint(point: Vector): Vector {
+        const rawPoint = VectorOps.intoRaw(point);
+        let result = VectorOps.fromRaw(
+            this.rawSet.rbVelocityAtPoint(this.handle, rawPoint),
+        );
+        rawPoint.free();
+        return result;
+    }
+
     // #if DIM3
     /**
      * The angular velocity of this rigid-body.

src/dynamics/rigid_body.rs

@@ -4,6 +4,7 @@ use crate::geometry::RawColliderSet;
 use crate::math::RawSdpMatrix3;
 use crate::math::{RawRotation, RawVector};
 use crate::utils::{self, FlatHandle};
+use na::Point;
 use rapier::dynamics::MassProperties;
 use wasm_bindgen::prelude::*;
 
@@ -297,6 +298,13 @@ impl RawRigidBodySet {
         self.map(handle, |rb| RawVector(*rb.angvel()))
     }
 
+    /// The velocity of the given world-space point on this rigid-body.
+    pub fn rbVelocityAtPoint(&self, handle: FlatHandle, point: &RawVector) -> RawVector {
+        self.map(handle, |rb| {
+            rb.velocity_at_point(&Point::from(point.0)).into()
+        })
+    }
+
     pub fn rbLockTranslations(&mut self, handle: FlatHandle, locked: bool, wake_up: bool) {
         self.map_mut(handle, |rb| rb.lock_translations(locked, wake_up))
     }