Checking if there is a collider when calling SoftBody::remove_collision_exception_with

[Duddino]

fixes #46651

[pouleyKetchoupp]

Thanks for your contribution! Although instead of raising an error, this case could be handled properly in the call to remove_collision_exception the same way it already does for add_collision_exception.

This is the code for add_collision_exception:

godot/modules/bullet/collision_object_bullet.cpp

Lines 138 to 147 in 17e6638

	void CollisionObjectBullet::add_collision_exception(const CollisionObjectBullet *p_ignoreCollisionObject) {
	exceptions.insert(p_ignoreCollisionObject->get_self());
	if (!bt_collision_object) {
	return;
	}
	bt_collision_object->setIgnoreCollisionCheck(p_ignoreCollisionObject->bt_collision_object, true);
	if (space) {
	space->get_broadphase()->getOverlappingPairCache()->cleanProxyFromPairs(bt_collision_object->getBroadphaseHandle(), space->get_dispatcher());
	}
	}

The same check on bt_collision_object could be done here:

godot/modules/bullet/collision_object_bullet.cpp

Lines 149 to 155 in 17e6638

	void CollisionObjectBullet::remove_collision_exception(const CollisionObjectBullet *p_ignoreCollisionObject) {
	exceptions.erase(p_ignoreCollisionObject->get_self());
	bt_collision_object->setIgnoreCollisionCheck(p_ignoreCollisionObject->bt_collision_object, false);
	if (space) {
	space->get_broadphase()->getOverlappingPairCache()->cleanProxyFromPairs(bt_collision_object->getBroadphaseHandle(), space->get_dispatcher());
	}
	}

And this method could also have a similar check:

godot/modules/bullet/collision_object_bullet.cpp

Lines 161 to 168 in 17e6638

	void CollisionObjectBullet::set_collision_enabled(bool p_enabled) {
	collisionsEnabled = p_enabled;
	if (collisionsEnabled) {
	bt_collision_object->setCollisionFlags(bt_collision_object->getCollisionFlags() & (~btCollisionObject::CF_NO_CONTACT_RESPONSE));
	} else {
	bt_collision_object->setCollisionFlags(bt_collision_object->getCollisionFlags() | btCollisionObject::CF_NO_CONTACT_RESPONSE);
	}
	}

And finally this one could benefit from a change to make it safe:

godot/modules/bullet/collision_object_bullet.cpp

Lines 157 to 160 in 17e6638

	bool CollisionObjectBullet::has_collision_exception(const CollisionObjectBullet *p_otherCollisionObject) const {
	return !bt_collision_object->checkCollideWith(p_otherCollisionObject->bt_collision_object);
	}

It could be replaced with:

bool CollisionObjectBullet::has_collision_exception(const CollisionObjectBullet *p_otherCollisionObject) const { 
 	return exceptions.has(p_otherCollisionObject->get_self());
 } 

It should be the exact same result but this way it wouldn't rely on bt_collision_object being valid.

One last piece of advice is, since Bullet is disabled on master at the moment (it's not compiled at all), make sure to test on the 3.2 branch locally (this PR can still be on master though).

[akien-mga]

Thanks!

[akien-mga]

Cherry-picked for 3.2.4.