/**
* Changes the length of the rope, adding or removing particles from its end as needed (as long as there are enough pooled particles
* left). Since particles are added/removed to/from the end only, any existing particle data (masses, editor selection data) will
* be preserved for existing particles when adding new ones.
*/
public void ChangeLength(float newLength)
{
if (rope == null)
{
return;
}
// Clamp new length to sane limits:
newLength = Mathf.Clamp(newLength, 0, (rope.TotalParticles - 1) * rope.InterparticleDistance);
// find current extrusion constraint:
int constraint = rope.GetConstraintIndexAtNormalizedCoordinate(normalizedCoord);
// get constraint batch:
ObiDistanceConstraintBatch distanceBatch = rope.DistanceConstraints.GetFirstBatch();
// calculate the change in rope length:
float lengthChange = newLength - rope.RestLength;
// calculate length change of current constraint:
float constraintLengthChange = Mathf.Clamp(lengthChange, -distanceBatch.restLengths[constraint], rope.InterparticleDistance - distanceBatch.restLengths[constraint]);
distanceBatch.restLengths[constraint] += constraintLengthChange;
lengthChange -= constraintLengthChange;
// figure out how many particles we need to add (or remove) and what length will remain after that:
int particleChange = lengthChange > 0 ? Mathf.CeilToInt(lengthChange / rope.InterparticleDistance): Mathf.FloorToInt(lengthChange / rope.InterparticleDistance);
float remainingLenght = ObiUtils.Mod(lengthChange, rope.InterparticleDistance);
if (particleChange > 0)
{
particleChange = AddParticles(particleChange);
// we cannot add any particles, so extend the segment as much as possible.
if (particleChange == 0)
{
remainingLenght = rope.InterparticleDistance;
}
// Add remaining lenght to the new constraint:
constraint = rope.GetConstraintIndexAtNormalizedCoordinate(normalizedCoord);
distanceBatch.restLengths[constraint] = remainingLenght;
}
else if (particleChange < 0)
{
particleChange = RemoveParticles(-particleChange);
// we cannot remove any particles, so reduce the segment as much as possible:
if (particleChange == 0)
{
remainingLenght = 0;
}
// Add remaining lenght to the new constraint:
constraint = rope.GetConstraintIndexAtNormalizedCoordinate(normalizedCoord);
distanceBatch.restLengths[constraint] = remainingLenght;
}
distanceBatch.PushDataToSolver(rope.DistanceConstraints);
// Update rest length:
rope.RecalculateLenght();
}
