public override void Update(Particle part)
{
Vector2 force = point - part.position;
MathExtra.SetVectorLength(ref force, strength);
part.AddForce(force);
}
public virtual void Update()
{
if (life != -1)
{
normalizedLifetime = 1 - ((float)(life--) / lifeLength);
}
else
{
normalizedLifetime = 1;
}
if (life == 0)
{
engine.DestroyParticle(this);
}
foreach (ParticleMethod method in methods)
{
method.Update(this);
}
velocity += acceleration;
MathExtra.RestrictVectorLength(ref velocity, maxSpeed);
position += velocity;
acceleration = Vector2.Zero;
}
/// <summary>
/// Restricts a vector based on different components.
/// </summary>
public static void RestrictComponentLength(ref Vector2 vector, Vector2 xDirection, float x, float y)
{
Vector2 _xPart = MathExtra.GetProjectionVector(vector, xDirection);
Vector2 _yPart = vector - _xPart;
RestrictVectorLength(ref _xPart, x);
RestrictVectorLength(ref _yPart, y);
vector = _xPart + _yPart;
}
public static void DrawCircle(SpriteBatch spriteBatch, Vector2 position, float radius, Color color, int resolution)
{
Vector2 first = position + new Vector2(MathExtra.ComponentX(radius, 0f), MathExtra.ComponentY(radius, 0f));
Vector2 prev = first;
for (int i = 1; i < resolution; i++)
{
float angle = (float)((float)i * 2.0f * Math.PI / resolution);
Vector2 p = position + new Vector2(MathExtra.ComponentX(radius, angle), MathExtra.ComponentY(radius, angle));
DrawLine(spriteBatch, prev, p, color);
prev = p;
}
DrawLine(spriteBatch, prev, first, color);
}