f.y = coef * n.y;
final Vec2 velData = m_velocityBuffer.data[a];
final float particleInvMass = getParticleInvMass();
velData.x -= particleInvMass * f.x;
velData.y -= particleInvMass * f.y;
b.applyLinearImpulse(f, p, true);
}
for (int k = 0; k < m_contactCount; k++) {
ParticleContact contact = m_contactBuffer[k];
int a = contact.indexA;
int b = contact.indexB;