public void update(float dt) {
if (mIsActive && mEmissionRate > 0) {
float rate = 1.0f / mEmissionRate;
// issue #1201, prevent bursts of particles, due to too high emitCounter
if (mParticleCount < mTotalParticles) {
mEmitCounter += dt;
}
while (mParticleCount < mTotalParticles && mEmitCounter > rate) {
this.addParticle();
mEmitCounter -= rate;
}
mElapsed += dt;
if (mDuration != -1 && mDuration < mElapsed) {
this.stopEmitting();
}
}
mParticleIdx = 0;
if (mIsVisible) {
boolean needInvalidate = mParticleIdx < mParticleCount;
while (mParticleIdx < mParticleCount) {
Particle p = mParticles[mParticleIdx];
// life
p.timeToLive -= dt;
if (p.timeToLive > 0) {
// Mode A: gravity, direction, tangential accel & radial accel
if (mEmitterMode == EmitterMode.MODE_GRAVITY) {
Point tmp, radial, tangential;
// radial acceleration
if (p.pos.x != 0 || p.pos.y != 0) {
radial = Point.Normalize(p.pos);
} else {
radial = new Point();
}
tangential = radial;
radial = Point.mult(radial, p.modeA.radialAccel);
// tangential acceleration
float newY = tangential.x;
tangential.x = -tangential.y;
tangential.y = newY;
tangential.multBy(p.modeA.tangentialAccel);
// (gravity + radial + tangential) * dt
// tmp = Point.add(Point.add(radial, tangential), modeA.gravity);
tmp = tangential;
tmp.addBy(radial);
tmp.addBy(modeA.gravity);
tmp.multBy(dt);
p.modeA.dir.addBy(tmp);
p.pos.addBy(Point.mult(p.modeA.dir, dt));
} else { // Mode B: radius movement
// Update the angle and radius of the particle.
p.modeB.angle += p.modeB.degreesPerSecond * dt;
p.modeB.radius += p.modeB.deltaRadius * dt;
p.pos.x = (float) (-Math.cos(p.modeB.angle) * p.modeB.radius);
p.pos.y = (float) (-Math.sin(p.modeB.angle) * p.modeB.radius);
}
// color
int r = Color.red(p.color) + (int) (p.deltaColor.r * dt);
int g = Color.green(p.color) + (int) (p.deltaColor.g * dt);
int b = Color.blue(p.color) + (int) (p.deltaColor.b * dt);
int a = Color.alpha(p.color) + (int) (p.deltaColor.a * dt);
p.color = Color.argb(a, r, g, b);
// size
p.size += (p.deltaSize * dt);
p.size = Math.max(0, p.size);
// angle
p.rotation += (p.deltaRotation * dt);
// update particle counter
++mParticleIdx;
} else { // life < 0
if (mParticleIdx != mParticleCount - 1) {
mParticles[mParticleIdx].copy(mParticles[mParticleCount - 1]);
}
--mParticleCount;
}
} // while
if (needInvalidate && null != mCallbackRef) {
UpdateCallback callback = mCallbackRef.get();
if (null != callback) {
callback.needInvalidate();
}
}
}
postStep();
}
