Can Box2D show a collision between two objects?

[Anton19780301]

I apologize if the question is stupid, I just started learning Box2D, can this plugin help you figure out whether objects overlap each other or not?

[bjorn]

Each Fixture has beginContact and endContact signals, which indicate which other fixture(s) are being touched:

qml-box2d/box2dfixture.h

Lines 99 to 100 in 0bb88a6

	void beginContact(Box2DFixture *other);
	void endContact(Box2DFixture *other);

There are also preSolve and postSolve signals for contacts between bodies coming in at the World instance, which are implemented using a Box2D ContactListener, they can be used to tweak the behavior:

qml-box2d/box2dworld.cpp

Lines 109 to 121 in 0bb88a6

	void ContactListener::PreSolve(b2Contact *contact, const b2Manifold *oldManifold)
	{
	Q_UNUSED(oldManifold)
	mContact.setContact(contact);
	emit mWorld->preSolve(&mContact);
	}
	void ContactListener::PostSolve(b2Contact *contact, const b2ContactImpulse *impulse)
	{
	Q_UNUSED(impulse)
	mContact.setContact(contact);
	emit mWorld->postSolve(&mContact);
	}

Finally there is a World.rayCast function, to see if you will hit something when drawing a line:

qml-box2d/box2dworld.cpp

Lines 340 to 345 in 0bb88a6

	void Box2DWorld::rayCast(Box2DRayCast *rayCast,
	const QPointF &point1,
	const QPointF &point2)
	{
	mWorld.RayCast(rayCast, toMeters(point1), toMeters(point2));
	}

You can find each of these functionalities used in some of the examples, especially the "contacts" example.