C++ Body::SetAwake方法代码示例

// Update the contact manifold and touching status.
// Note: do not assume the fixture AABBs are overlapping or are valid.
void Contact::Update(ContactListener* listener)
{
    Manifold oldManifold = m_manifold;

    // Re-enable this contact.
    m_flags |= e_enabledFlag;

    bool touching = false;
    bool wasTouching = (m_flags & e_touchingFlag) == e_touchingFlag;

    bool sensorA = m_fixtureA->IsSensor();
    bool sensorB = m_fixtureB->IsSensor();
    bool sensor = sensorA || sensorB;

    Body* bodyA = m_fixtureA->GetBody();
    Body* bodyB = m_fixtureB->GetBody();
    const Transform& xfA = bodyA->GetTransform();
    const Transform& xfB = bodyB->GetTransform();

    // Is this contact a sensor?
    if (sensor)
    {
        const Shape* shapeA = m_fixtureA->GetShape();
        const Shape* shapeB = m_fixtureB->GetShape();
        touching = TestOverlap(shapeA, m_indexA, shapeB, m_indexB, xfA, xfB);

        // Sensors don't generate manifolds.
        m_manifold.pointCount = 0;
    }
    else
    {
        Evaluate(&m_manifold, xfA, xfB);
        touching = m_manifold.pointCount > 0;

        // Match old contact ids to new contact ids and copy the
        // stored impulses to warm start the solver.
        for (int32 i = 0; i < m_manifold.pointCount; ++i)
        {
            ManifoldPoint* mp2 = m_manifold.points + i;
            mp2->normalImpulse = 0.0f;
            mp2->tangentImpulse = 0.0f;
            ContactID id2 = mp2->id;

            for (int32 j = 0; j < oldManifold.pointCount; ++j)
            {
                ManifoldPoint* mp1 = oldManifold.points + j;

                if (mp1->id.key == id2.key)
                {
                    mp2->normalImpulse = mp1->normalImpulse;
                    mp2->tangentImpulse = mp1->tangentImpulse;
                    break;
                }
            }
        }

        if (touching != wasTouching)
        {
            bodyA->SetAwake(true);
            bodyB->SetAwake(true);
        }
    }

    if (touching)
    {
        m_flags |= e_touchingFlag;
    }
    else
    {
        m_flags &= ~e_touchingFlag;
    }

    if (wasTouching == false && touching == true && listener)
    {
        listener->BeginContact(this);
    }

    if (wasTouching == true && touching == false && listener)
    {
        listener->EndContact(this);
    }

    if (sensor == false && touching && listener)
    {
        listener->PreSolve(this, &oldManifold);
    }
}

//.........这里部分代码省略.........
		glm::vec2 translation = h * v;
		if (glm::dot(translation, translation) > maxTranslationSquared)
		{
			real32 ratio = maxTranslation / translation.length();
			v *= ratio;
		}

		real32 rotation = h * w;
		if (rotation * rotation > maxRotationSquared)
		{
			real32 ratio = maxRotation / glm::abs(rotation);
			w *= ratio;
		}

		// Integrate
		c += h * v;
		a += h * w;

		m_positions[i].c = c;
		m_positions[i].a = a;
		m_velocities[i].v = v;
		m_velocities[i].w = w;
	}

	// Solve position constraints
	captureTimer = Services::getPlatform()->getTime();
	bool positionSolved = false;
	for (s32 i = 0; i < step.positionIterations; ++i)
	{
		bool contactsOkay = contactSolver.SolvePositionConstraints();

		bool jointsOkay = true;
		for (s32 i = 0; i < m_jointCount; ++i)
		{
			bool jointOkay = m_joints[i]->SolvePositionConstraints(solverData);
			jointsOkay = jointsOkay && jointOkay;
		}

		if (contactsOkay && jointsOkay)
		{
			// Exit early if the position errors are small.
			positionSolved = true;
			break;
		}
	}

	// Copy state buffers back to the bodies
	for (s32 i = 0; i < m_bodyCount; ++i)
	{
		Body* body = m_bodies[i];
		body->m_sweep.c = m_positions[i].c;
		body->m_sweep.a = m_positions[i].a;
		body->m_linearVelocity = m_velocities[i].v;
		body->m_angularVelocity = m_velocities[i].w;
		body->SynchronizeTransform2D();
	}

	profile->solvePosition = Services::getPlatform()->getTime()-captureTimer;

	Report(contactSolver.m_velocityConstraints);

	if (allowSleep)
	{
		real32 minSleepTime = FLT_MAX;

		const real32 linTolSqr = linearSleepTolerance * linearSleepTolerance;
		const real32 angTolSqr = angularSleepTolerance * angularSleepTolerance;

		for (s32 i = 0; i < m_bodyCount; ++i)
		{
			Body* b = m_bodies[i];
			if (b->GetType() == staticBody)
			{
				continue;
			}

			if ((b->m_flags & Body::autoSleepFlag) == 0 ||
				b->m_angularVelocity * b->m_angularVelocity > angTolSqr ||
				glm::dot(b->m_linearVelocity, b->m_linearVelocity) > linTolSqr)
			{
				b->m_sleepTime = 0.0f;
				minSleepTime = 0.0f;
			}
			else
			{
				b->m_sleepTime += h;
				minSleepTime = glm::min(minSleepTime, b->m_sleepTime);
			}
		}

		if (minSleepTime >= timeToSleep && positionSolved)
		{
			for (s32 i = 0; i < m_bodyCount; ++i)
			{
				Body* b = m_bodies[i];
				b->SetAwake(false);
			}
		}
	}
}

//.........这里部分代码省略.........
	// TODO_ERIN use a hash table to remove a potential bottleneck when both
	// bodies have a lot of contacts.
	// Does a contact already exist?
	ContactEdge* edge = bodyB->GetContactList();
	while (edge)
	{
		if (edge->other == bodyA)
		{
			Fixture* fA = edge->contact->GetFixtureA();
			Fixture* fB = edge->contact->GetFixtureB();
			s32 iA = edge->contact->GetChildIndexA();
			s32 iB = edge->contact->GetChildIndexB();

			if (fA == fixtureA && fB == fixtureB && iA == indexA && iB == indexB)
			{
				// A contact already exists.
				return;
			}

			if (fA == fixtureB && fB == fixtureA && iA == indexB && iB == indexA)
			{
				// A contact already exists.
				return;
			}
		}

		edge = edge->next;
	}

	// Does a joint override collision? Is at least one body dynamic?
	if (bodyB->ShouldCollide(bodyA) == false)
	{
		return;
	}

	// Check user filtering.
	if (m_contactFilter && m_contactFilter->ShouldCollide(fixtureA, fixtureB) == false)
	{
		return;
	}

	// Call the factory.
	Contact* c = Contact::Create(fixtureA, indexA, fixtureB, indexB, m_allocator);
	if (c == NULL)
	{
		return;
	}

	// Contact creation may swap fixtures.
	fixtureA = c->GetFixtureA();
	fixtureB = c->GetFixtureB();
	indexA = c->GetChildIndexA();
	indexB = c->GetChildIndexB();
	bodyA = fixtureA->GetBody();
	bodyB = fixtureB->GetBody();

	// Insert into the world.
	c->m_prev = NULL;
	c->m_next = m_contactList;
	if (m_contactList != NULL)
	{
		m_contactList->m_prev = c;
	}
	m_contactList = c;

	// Connect to island graph.

	// Connect to body A
	c->m_nodeA.contact = c;
	c->m_nodeA.other = bodyB;

	c->m_nodeA.prev = NULL;
	c->m_nodeA.next = bodyA->m_contactList;
	if (bodyA->m_contactList != NULL)
	{
		bodyA->m_contactList->prev = &c->m_nodeA;
	}
	bodyA->m_contactList = &c->m_nodeA;

	// Connect to body B
	c->m_nodeB.contact = c;
	c->m_nodeB.other = bodyA;

	c->m_nodeB.prev = NULL;
	c->m_nodeB.next = bodyB->m_contactList;
	if (bodyB->m_contactList != NULL)
	{
		bodyB->m_contactList->prev = &c->m_nodeB;
	}
	bodyB->m_contactList = &c->m_nodeB;

	// Wake up the bodies
	if (fixtureA->IsSensor() == false && fixtureB->IsSensor() == false)
	{
		bodyA->SetAwake(true);
		bodyB->SetAwake(true);
	}

	++m_contactCount;
}