/// <summary>
/// Draws the specified particle.
/// </summary>
/// <param name="particle">The particle.</param>
public void Draw(Particle particle)
{
Drawer.Draw(
TextureStatic.Get("particle3"),
particle.Position,
null,
particle.color,
particle.Rotation,
TextureStatic.GetOrigin("particle3"),
particle.Scale,
SpriteEffects.None,
0.11f + 0.088f * (1f - (GameClock.Now - particle.CreationTime) / Duration));
}
/// <summary>
/// Updates the specified particle. This should NOT do physics, but everything else. Assume
/// that the physics is performed before this is called.
/// </summary>
/// <param name="particle">The particle.</param>
public void Update(Particle particle)
{
if (particle.CreationTime + Duration < GameClock.Now)
{
particle.Dispose();
}
else
{
if (particle.Position.Y > 1080 || particle.Position.Y < 0)
{
particle.Velocity.Y = -particle.Velocity.Y;
}
if (particle.Position.X > 1920 || particle.Position.X < 0)
{
particle.Velocity.X = -particle.Velocity.X;
}
float alpha = 0.75f * (1f - Math.Abs(1f - 2f * MathHelper.Lerp(1f, 0f, (GameClock.Now - particle.CreationTime) / Duration)));
// Why does this work? See: http://en.wikipedia.org/wiki/HSL_and_HSV#Converting_to_RGB
long offset = particle.CreationTime % (long)Duration;
float hue = 6f * offset / Duration;
float x = 1 - Math.Abs(hue % 2 - 1);
if (hue < 1)
{
particle.color.R = (byte)(255 * alpha);
particle.color.G = (byte)(x * 255 * alpha);
particle.color.B = 0;
particle.color.A = (byte)(255 * alpha);
}
else if (hue < 2)
{
particle.color.R = (byte)(x * 255 * alpha);
particle.color.G = (byte)(255 * alpha);
particle.color.B = 0;
particle.color.A = (byte)(255 * alpha);
}
else if (hue < 3)
{
particle.color.R = 0;
particle.color.G = (byte)(255 * alpha);
particle.color.B = (byte)(x * 255 * alpha);
particle.color.A = (byte)(255 * alpha);
}
else if (hue < 4)
{
particle.color.R = 0;
particle.color.G = (byte)(x * 255 * alpha);
particle.color.B = (byte)(255 * alpha);
particle.color.A = (byte)(255 * alpha);
}
else if (hue < 5)
{
particle.color.R = (byte)(x * 255 * alpha);
particle.color.G = 0;
particle.color.B = (byte)(255 * alpha);
particle.color.A = (byte)(255 * alpha);
}
else
{
particle.color.R = (byte)(255 * alpha);
particle.color.G = 0;
particle.color.B = (byte)(x * 255 * alpha);
particle.color.A = (byte)(255 * alpha);
}
// Finally, set the scale as the inverse of transparency to get a "fade-out" effect.
// Note that the scale is capped at 3 so that the graphics card does not catch on fire.
if (alpha != 0)
{
particle.Scale = Math.Min(1f / alpha, 3f);
}
else
{
particle.Scale = 3f;
}
}
}
