compute_contact.cc
a96c24d89edemaster

compute_contact.cc
View Options

			#include "compute_contact.hh"
			#include "ping_pong_ball.hh"
			#include <cmath>
			/* -------------------------------------------------------------------------- */
			void ComputeContact::setPenalty(Real penalty) {
			this->penalty = penalty;
			}
			/* -------------------------------------------------------------------------- */
			void ComputeContact::computePairInteraction(Particle& par1, Particle& par2) {


			PingPongBall& p1 = static_cast<PingPongBall&> (par1);
			PingPongBall& p2 = static_cast<PingPongBall&> (par2);

			p2.getForce() = 0;
			p1.getForce() = 0;

			auto v_r = p2.getPosition() - p1.getPosition();
			auto r2 = v_r.squaredNorm();

			if (r2 == 0.){
			return;
			}

			// compute the distance
			auto r = sqrt(r2);
			v_r *= 1 / r;

			Real p = 0;
			if (r < p1.getRadius() + p2.getRadius()){
			p = p1.getRadius() + p2.getRadius() - r;
			}
			// compute the pair force
			// std::cout << "Diff pos:" << v_r[0] << " " << v_r[1] << " " << v_r[2] << "; P vect: " << p << std::endl;
			auto force = v_r * this->penalty * p;

			// add up the force for both concerned particles
			p2.getForce() -= force;
			p1.getForce() += force;
			}