/**
* Computes a list of points along the spline which are close to uniformly separated by the given
* step distance. The uniform distribution is only an approximation and is based on the estimated
* arc length of the polyline. The distance between returned points might vary in places,
* especially if there're sharp angles between line segments.
*
* @param step
* @param doAddFinalVertex true, if the last vertex computed should be added regardless of its
* distance.
* @return point list
*/
public List<Vec3D> getDecimatedVertices(float step, boolean doAddFinalVertex) {
ArrayList<Vec3D> uniform = new ArrayList<Vec3D>();
if (vertices.size() < 3) {
if (vertices.size() == 2) {
new Line3D(vertices.get(0), vertices.get(1)).splitIntoSegments(uniform, step, true);
if (!doAddFinalVertex) {
uniform.remove(uniform.size() - 1);
}
} else {
return null;
}
}
float arcLen = getEstimatedArcLength();
double delta = (double) step / arcLen;
int currIdx = 0;
for (double t = 0; t < 1.0; t += delta) {
double currT = t * arcLen;
while (currT >= arcLenIndex[currIdx]) {
currIdx++;
}
ReadonlyVec3D p = vertices.get(currIdx - 1);
ReadonlyVec3D q = vertices.get(currIdx);
float frac =
(float)
((currT - arcLenIndex[currIdx - 1])
/ (arcLenIndex[currIdx] - arcLenIndex[currIdx - 1]));
Vec3D i = p.interpolateTo(q, frac);
uniform.add(i);
}
if (doAddFinalVertex) {
uniform.add(vertices.get(vertices.size() - 1).copy());
}
return uniform;
}
public float getEstimatedArcLength() {
if (arcLenIndex == null || (arcLenIndex != null && arcLenIndex.length != vertices.size())) {
arcLenIndex = new float[vertices.size()];
}
float arcLen = 0;
for (int i = 1; i < arcLenIndex.length; i++) {
ReadonlyVec3D p = vertices.get(i - 1);
ReadonlyVec3D q = vertices.get(i);
arcLen += p.distanceTo(q);
arcLenIndex[i] = arcLen;
}
return arcLen;
}
public LineStrip3D add(ReadonlyVec3D p) {
vertices.add(p.copy());
return this;
}
/**
* Creates particle at the position of the passed in vector
*
* @param v position
*/
public VerletParticle3D(ReadonlyVec3D v) {
this(v.x(), v.y(), v.z(), 1);
}
/**
* Creates particle with weight w at the position of the passed in vector
*
* @param v position
* @param w weight
*/
public VerletParticle3D(ReadonlyVec3D v, float w) {
this(v.x(), v.y(), v.z(), w);
}