public void Update(float particleAge, double totalMilliseconds, double elapsedSeconds, Particle2D particle)
{
Vector2 distance = Vector2.Subtract(Position, particle.Position);
if (distance.LengthSquared() < Radius * Radius)
{
Vector2 force = Vector2.Normalize(distance);
force = Vector2.Multiply(force, Strength);
force = Vector2.Multiply(force, (float) elapsedSeconds);
particle.Affect(ref force);
}
}
public void Update(float particleAge, double totalMilliseconds, double elapsedSeconds,
Particle2D particle)
{
var deltaGrav = Vector2.Multiply(Gravity, (float) elapsedSeconds);
particle.Affect(ref deltaGrav);
}