ApplyBuoyancyImpulse will return true if it applied an impulse

Jolt/Physics/Body/Body.cpp

@@ -164,7 +164,7 @@ Body::ECanSleep Body::UpdateSleepStateInternal(float inDeltaTime, float inMaxMov
 	return mMotionProperties->mSleepTestTimer >= inTimeBeforeSleep? ECanSleep::CanSleep : ECanSleep::CannotSleep;
 }
 
-void Body::ApplyBuoyancyImpulse(const Plane &inSurface, float inBuoyancy, float inLinearDrag, float inAngularDrag, Vec3Arg inFluidVelocity, Vec3Arg inGravity, float inDeltaTime)
+bool Body::ApplyBuoyancyImpulse(const Plane &inSurface, float inBuoyancy, float inLinearDrag, float inAngularDrag, Vec3Arg inFluidVelocity, Vec3Arg inGravity, float inDeltaTime)
 {
 	JPH_PROFILE_FUNCTION();
 
@@ -252,7 +252,10 @@ void Body::ApplyBuoyancyImpulse(const Plane &inSurface, float inBuoyancy, float
 		// Calculate total delta angular velocity due to drag and buoyancy
 		Vec3 delta_angular_velocity = drag_delta_angular_velocity + inv_inertia * relative_center_of_buoyancy.Cross(buoyancy_impulse + drag_impulse);
 		mMotionProperties->AddAngularVelocityStep(delta_angular_velocity);
+		return true;
 	}
+
+	return false;
 }
 
 void Body::SaveState(StateRecorder &inStream) const

Jolt/Physics/Body/Body.h

@@ -148,7 +148,8 @@ public:
 	/// @param inFluidVelocity The average velocity of the fluid (in m/s) in which the body resides
 	/// @param inGravity The graviy vector (pointing down)
 	/// @param inDeltaTime Delta time of the next simulation step (in s)
-	void					ApplyBuoyancyImpulse(const Plane &inSurface, float inBuoyancy, float inLinearDrag, float inAngularDrag, Vec3Arg inFluidVelocity, Vec3Arg inGravity, float inDeltaTime);
+	/// @return true if an impulse was applied, false if the body was not in the fluid
+	bool					ApplyBuoyancyImpulse(const Plane &inSurface, float inBuoyancy, float inLinearDrag, float inAngularDrag, Vec3Arg inFluidVelocity, Vec3Arg inGravity, float inDeltaTime);
 
 	/// Check if this body has been added to the physics system
 	inline bool				IsInBroadPhase() const											{ return (mFlags.load(memory_order_relaxed) & uint8(EFlags::IsInBroadPhase)) != 0; }