/// <summary>
/// Updates the emitter, creating the appropriate number of particles
/// in the appropriate positions.
/// </summary>
public override void Update(ref GameTime gameTime)//, Vector3 newPosition)
{
//are we dead??
if (dead)
{
//Check particle system to see it its dead
if (particleSystem.dead)
{//yes its dead so disable it and then disable myself (XParticleEmitter)
particleSystem.Disable();
this.Disable();
}
return; //particlesystem is not dead yet so return here to avoid any other processing/new particles and check again next update
}
// Work out how much time has passed since the previous update.
float elapsedTime = (float)gameTime.ElapsedGameTime.TotalSeconds;
if (elapsedTime > 0)
{
// Work out how fast we are moving.
Vector3 velocity = (newPosition - previousPosition) / elapsedTime;
// If we had any time left over that we didn't use during the
// previous update, add that to the current elapsed time.
float timeToSpend = timeLeftOver + elapsedTime;
// Counter for looping over the time interval.
float currentTime = -timeLeftOver;
// Create particles as long as we have a big enough time interval.
while (timeToSpend > timeBetweenParticles)
{
currentTime += timeBetweenParticles;
timeToSpend -= timeBetweenParticles;
// Work out the optimal position for this particle. This will produce
// evenly spaced particles regardless of the object speed, particle
// creation frequency, or game update rate.
float mu = currentTime / elapsedTime;
Vector3 position = Vector3.Lerp(previousPosition, newPosition, mu);
// Create the particle.
particleSystem.AddParticle(position, velocity);
}
// Store any time we didn't use, so it can be part of the next update.
timeLeftOver = timeToSpend;
}
previousPosition = newPosition;
}
/// <summary>
/// Updates the projectile.
/// </summary>
public override void Update(ref GameTime gameTime)
{
//if dead then disable all XComponents related to this projectile
//but we can't do it right away because the explosion is not finished yet!
if (dead)
{
//set flag trailemitter that its dead (it will disable itself and its particle system automatically)
trailEmitter.dead = true;
//check if our explosion and explosion smoke particle systems are dead if so disable them and then disable ourself!
if (explosionParticles.dead && explosionSmokeParticles.dead)
{
explosionParticles.Disable();
explosionSmokeParticles.Disable();
this.Disable();
}
return;
}
float elapsedTime = (float)gameTime.ElapsedGameTime.TotalSeconds;
// Simple projectile physics.
position += velocity * elapsedTime;
velocity.Y -= elapsedTime * gravity;
age += elapsedTime;
// Update the particle emitter, which will create our particle trail.
trailEmitter.newPosition = position;
//trailEmitter.Update(gameTime, position); //changed XRenderer will call update on this class automatically
// If enough time has passed, explode! Note how we pass our velocity
// in to the AddParticle method: this lets the explosion be influenced
// by the speed and direction of the projectile which created it.
if (age > projectileLifespan)
{
for (int i = 0; i < numExplosionParticles; i++)
{
explosionParticles.AddParticle(position, velocity);
}
for (int i = 0; i < numExplosionSmokeParticles; i++)
{
explosionSmokeParticles.AddParticle(position, velocity);
}
//flag as dead
dead = true;
}
}