public MightBeCollision Enact()
{
myPhysicsObject_1.UpdateVelocity(vx_1, vy_1);
myPhysicsObject_2.UpdateVelocity(vx_2, vy_2);
return(res);
}
/// <summary>
/// Handles a collision between the physics object and a surface described by a surface
/// normal. The object's velocity will change such that the angle of incidence and the
/// angle of reflection are equal with respect to the surface normal. Note that this
/// method does not check whether any sort of a collision actually occurred - it trusts
/// the caller to determine that.
/// </summary>
/// <param name="physicsObject">The object whose velocity will change as a result of the
/// collision.</param>
/// <param name="surfaceNormal">The surface normal of the surface against which the object
/// collided.</param>
/// <param name="restitution">Coefficient of restitution. 1.0f means an elastic collision (no
/// energy lost), so the object will bounce back as forcefully as it went in. For 0.0f, the
/// object will effectively stop at the surface.</param>
private void HandleCollisionWithSurface(IPhysicsObject physicsObject, Vector3 surfaceNormal,
float restitution)
{
Vector3 oldVelocity = physicsObject.GetVelocity();
// Project velocity vector onto the surface normal
float v_dot_n = Vector3.Dot(oldVelocity, surfaceNormal);
// Calculate the normal force
Vector3 normalForce = -(1.0f + restitution) * v_dot_n * surfaceNormal;
// Add the normal force to the motion vector to get the new velocity
Vector3 newVelocity = oldVelocity + normalForce;
physicsObject.UpdateVelocity(newVelocity);
}