我正在尝试为我的 box2d 主体实现焊接接头:
for(pos = _contactListener->_contacts.begin(); 
    pos != _contactListener->_contacts.end(); ++pos) {
    MyContact contact = *pos;
    b2Body *bodyA = contact.fixtureA->GetBody();
    b2Body *bodyB = contact.fixtureB->GetBody();
    b2Vec2 worldCoordsAnchorPoint = bodyA->GetWorldPoint (b2Vec2(0,0)); 
    b2WeldJointDef weldJointDef;
    weldJointDef.bodyA = bodyA;
    weldJointDef.bodyB = bodyB;
    weldJointDef.localAnchorA = weldJointDef.bodyA->GetLocalPoint(worldCoordsAnchorPoint);
    weldJointDef.localAnchorB = weldJointDef.bodyB->GetLocalPoint(worldCoordsAnchorPoint);
    weldJointDef.referenceAngle = weldJointDef.bodyB->GetAngle() - weldJointDef.bodyA->GetAngle();
    weldJointDef.collideConnected = true;
    weldJointDef.userData = @"tile";
    weldJointDef.Initialize(bodyA, bodyB, worldCoordsAnchorPoint);
    world->CreateJoint(&weldJointDef);
    //}
}
但我的fps非常低。我认为是因为我不检查身体是否是要焊接的。如何检查车身是否焊接?谢谢。