/// <summary>
/// Initialize a new particle using the values in this system.
/// </summary>
/// <param name="particle">The particle to be initialized.</param>
private void InitializeParticle(Particle particle)
{
// safety-check the parameter
if (particle == null)
{
throw new ArgumentNullException("particle");
}
// set the time remaining on the new particle
particle.TimeRemaining = RandomMath.RandomBetween(durationMinimum,
durationMaximum);
// generate a random direction
Vector2 direction = RandomMath.RandomDirection(releaseAngleMinimum,
releaseAngleMaximum);
// set the graphics data on the new particle
particle.Position = position + direction *
RandomMath.RandomBetween(releaseDistanceMinimum,
releaseDistanceMaximum);
particle.Velocity = direction * RandomMath.RandomBetween(velocityMinimum,
velocityMaximum);
if (particle.Velocity.LengthSquared() > 0f)
{
particle.Acceleration = direction *
RandomMath.RandomBetween(accelerationMinimum, accelerationMaximum);
}
else
{
particle.Acceleration = Vector2.Zero;
}
particle.Rotation = RandomMath.RandomBetween(0f, MathHelper.TwoPi);
particle.Scale = RandomMath.RandomBetween(scaleMinimum, scaleMaximum);
particle.Opacity = RandomMath.RandomBetween(opacityMinimum, opacityMaximum);
}
/// <summary>
/// Construct a new asteroid.
/// </summary>
/// <param name="world">The world that this asteroid belongs to.</param>
/// <param name="radius">The size of the asteroid.</param>
public Asteroid(float radius)
: base()
{
// safety-check the parameters
if (radius <= 0f)
{
throw new ArgumentOutOfRangeException("radius");
}
// set the collision data
this.radius = radius;
this.mass = this.radius * massRadiusRatio;
this.Velocity = RandomMath.RandomDirection() *
RandomMath.RandomBetween(initialSpeedMinimum, initialSpeedMaximum);
}