From 932fe6c976e8aa34b6830513c461f3d029c3816a Mon Sep 17 00:00:00 2001
From: Ki <williamkwooten14@gmail.com>
Date: Mon, 11 May 2026 02:19:09 -0400
Subject: [PATCH] feat: Add frame setter methods for revolute/prismatic joints

This implements the frame transformation capabilities requested in issue #271,
allowing users to set joint frames after joint creation via:
- setFrameX1() / setFrameX2() for rotation frames
- setLocalFrame1() / setLocalFrame2() for full frame (anchor + rotation)

These methods enable more flexible joint configuration in physics simulations,
particularly for use cases like VistaKine where joint frames need adjustment
after initial setup.

Fixes #271
---
 src.ts/dynamics/impulse_joint.ts | 42 ++++++++++++++++++++++++++++++++
 src/dynamics/impulse_joint.rs    | 29 ++++++++++++++++++++++
 2 files changed, 71 insertions(+)

diff --git a/src.ts/dynamics/impulse_joint.ts b/src.ts/dynamics/impulse_joint.ts
index 0c637ddf..1ea0177f 100644
--- a/src.ts/dynamics/impulse_joint.ts
+++ b/src.ts/dynamics/impulse_joint.ts
@@ -210,6 +210,48 @@ export class ImpulseJoint {
         rawPoint.free();
     }
 
+    // #if DIM3
+    /**
+     * Sets the rotation quaternion that aligns this joint's first local axis to the `x` axis.
+     */
+    public setFrameX1(rot: Rotation) {
+        const rawRot = RotationOps.intoRaw(rot);
+        this.rawSet.jointSetFrameX1(this.handle, rawRot);
+        rawRot.free();
+    }
+
+    /**
+     * Sets the rotation quaternion that aligns this joint's second local axis to the `x` axis.
+     */
+    public setFrameX2(rot: Rotation) {
+        const rawRot = RotationOps.intoRaw(rot);
+        this.rawSet.jointSetFrameX2(this.handle, rawRot);
+        rawRot.free();
+    }
+
+    /**
+     * Sets the full local frame (anchor position and rotation) for the first rigid-body attachment.
+     */
+    public setLocalFrame1(anchor: Vector, rot: Rotation) {
+        const rawAnchor = VectorOps.intoRaw(anchor);
+        const rawRot = RotationOps.intoRaw(rot);
+        this.rawSet.jointSetLocalFrame1(this.handle, rawAnchor, rawRot);
+        rawAnchor.free();
+        rawRot.free();
+    }
+
+    /**
+     * Sets the full local frame (anchor position and rotation) for the second rigid-body attachment.
+     */
+    public setLocalFrame2(anchor: Vector, rot: Rotation) {
+        const rawAnchor = VectorOps.intoRaw(anchor);
+        const rawRot = RotationOps.intoRaw(rot);
+        this.rawSet.jointSetLocalFrame2(this.handle, rawAnchor, rawRot);
+        rawAnchor.free();
+        rawRot.free();
+    }
+    // #endif
+
     /**
      * Controls whether contacts are computed between colliders attached
      * to the rigid-bodies linked by this joint.
diff --git a/src/dynamics/impulse_joint.rs b/src/dynamics/impulse_joint.rs
index bfbdf128..a9519a0f 100644
--- a/src/dynamics/impulse_joint.rs
+++ b/src/dynamics/impulse_joint.rs
@@ -2,6 +2,7 @@ use crate::dynamics::{RawImpulseJointSet, RawJointAxis, RawJointType, RawMotorMo
 use crate::math::{RawRotation, RawVector};
 use crate::utils::{self, FlatHandle};
 use rapier::dynamics::JointAxis;
+use rapier::math::Isometry;
 use wasm_bindgen::prelude::*;
 
 #[wasm_bindgen]
@@ -61,6 +62,34 @@ impl RawImpulseJointSet {
         })
     }
 
+    /// Sets the angular part of the joint's local frame relative to the first rigid-body.
+    pub fn jointSetFrameX1(&mut self, handle: FlatHandle, newRot: &RawRotation) {
+        self.map_mut(handle, |j| {
+            j.data.local_frame1.rotation = newRot.0;
+        });
+    }
+
+    /// Sets the angular part of the joint's local frame relative to the second rigid-body.
+    pub fn jointSetFrameX2(&mut self, handle: FlatHandle, newRot: &RawRotation) {
+        self.map_mut(handle, |j| {
+            j.data.local_frame2.rotation = newRot.0;
+        });
+    }
+
+    /// Sets the full local frame (anchor + rotation) for the first rigid-body attachment.
+    pub fn jointSetLocalFrame1(&mut self, handle: FlatHandle, anchor: &RawVector, rot: &RawRotation) {
+        self.map_mut(handle, |j| {
+            j.data.set_local_frame1(Isometry::from_parts(anchor.0.into(), rot.0));
+        });
+    }
+
+    /// Sets the full local frame (anchor + rotation) for the second rigid-body attachment.
+    pub fn jointSetLocalFrame2(&mut self, handle: FlatHandle, anchor: &RawVector, rot: &RawRotation) {
+        self.map_mut(handle, |j| {
+            j.data.set_local_frame2(Isometry::from_parts(anchor.0.into(), rot.0));
+        });
+    }
+
     /// Are contacts between the rigid-bodies attached by this joint enabled?
     pub fn jointContactsEnabled(&self, handle: FlatHandle) -> bool {
         self.map(handle, |j| j.data.contacts_enabled)