/**
* update position (using current position and velocity), color (interpolating between start and
* end color), size (interpolating between start and end size), spin (using parent's spin speed)
* and current age of particle. If this particle's age is greater than its lifespan, it is set to
* status DEAD.
*
* <p>Note that this only changes the parameters of the Particle, not the geometry the particle is
* associated with.
*
* @param secondsPassed number of seconds passed since last update.
* @return true if this particle is not ALIVE (in other words, if it is ready to be reused.)
*/
public boolean updateAndCheck(final double secondsPassed) {
if (status != Status.Alive) {
return true;
}
currentAge += secondsPassed * 1000; // add ms time to age
if (currentAge > lifeSpan) {
killParticle();
return true;
}
final Vector3 temp = Vector3.fetchTempInstance();
_position.addLocal(_velocity.multiply(secondsPassed * 1000f, temp));
Vector3.releaseTempInstance(temp);
// get interpolated values from appearance ramp:
parent.getRamp().getValuesAtAge(currentAge, lifeSpan, currColor, values, parent);
// interpolate colors
final int verts = ParticleSystem.getVertsForParticleType(type);
for (int x = 0; x < verts; x++) {
BufferUtils.setInBuffer(
currColor, parent.getParticleGeometry().getMeshData().getColorBuffer(), startIndex + x);
}
// check for tex animation
final int newTexIndex = parent.getTexAnimation().getTexIndexAtAge(currentAge, lifeSpan, parent);
// Update tex coords if applicable
if (currentTexIndex != newTexIndex) {
// Only supported in Quad type for now.
if (ParticleType.Quad.equals(parent.getParticleType())) {
// determine side
final float side = (float) Math.sqrt(parent.getTexQuantity());
int index = newTexIndex;
if (index >= parent.getTexQuantity()) {
index %= parent.getTexQuantity();
}
// figure row / col
final float row = side - (int) (index / side) - 1;
final float col = index % side;
// set texcoords
final float sU = col / side, eU = (col + 1) / side;
final float sV = row / side, eV = (row + 1) / side;
final FloatBuffer texs =
parent.getParticleGeometry().getMeshData().getTextureCoords(0).getBuffer();
texs.position(startIndex * 2);
texs.put(eU).put(sV);
texs.put(eU).put(eV);
texs.put(sU).put(eV);
texs.put(sU).put(sV);
texs.clear();
}
currentTexIndex = newTexIndex;
}
return false;
}
