@numericelements/knot-sequence/dist/KnotSequenceAndUtilities/prepareStrictlyIncreasingOpenKnotSeqCCfromStrictlyIncreasingPeriodicKnotSeq.js

A library for generating and manipulating knot sequences for b-spline curves and surfaces

import { KnotIndexStrictlyIncreasingSequence } from '../KnotIndexStrictlyIncreasingSequence.js';

function prepareStrictlyIncreasingOpenKnotSeqCCfromStrictlyIncreasingPeriodicKnotSeq(strictIncSeq) {
    const knotsOpenSequence = [];
    const multiplicitiesOpenSequence = [];
    const maxMultOrder = strictIncSeq.maxMultiplicityOrder;
    const lastIndex = strictIncSeq.length() - 1;
    const lastAbscissa = strictIncSeq.uMax;
    const multiplicityAtOrigin = strictIncSeq.knotMultiplicity(new KnotIndexStrictlyIncreasingSequence(0));
    let nbComplementaryKnots = maxMultOrder - (multiplicityAtOrigin - 1);
    let index = 0;
    while (index < nbComplementaryKnots) {
        const multiplicityExcess = nbComplementaryKnots - strictIncSeq.knotMultiplicity(new KnotIndexStrictlyIncreasingSequence(lastIndex - (index + 1))) - index;
        if (multiplicityExcess <= 0) {
            nbComplementaryKnots = index + 1;
            break;
        }
        else if (multiplicityExcess < (nbComplementaryKnots - (index + 1))) {
            nbComplementaryKnots = nbComplementaryKnots - multiplicityExcess;
            index++;
        }
        else {
            index++;
        }
    }
    let cumulativeMultiplicityFromOrigin = multiplicityAtOrigin;
    for (let i = 0; i < nbComplementaryKnots; i++) {
        knotsOpenSequence.splice(0, 0, (strictIncSeq.abscissaAtIndex(new KnotIndexStrictlyIncreasingSequence(lastIndex - (i + 1))) - lastAbscissa));
        let multiplicityCurrentKnot = strictIncSeq.knotMultiplicity(new KnotIndexStrictlyIncreasingSequence(lastIndex - (i + 1)));
        if ((cumulativeMultiplicityFromOrigin + multiplicityCurrentKnot) > maxMultOrder) {
            multiplicityCurrentKnot = maxMultOrder - cumulativeMultiplicityFromOrigin + 1;
        }
        cumulativeMultiplicityFromOrigin += multiplicityCurrentKnot;
        multiplicitiesOpenSequence.splice(0, 0, multiplicityCurrentKnot);
    }
    for (const knot of strictIncSeq) {
        if (knot !== undefined) {
            knotsOpenSequence.push(knot.abscissa);
            multiplicitiesOpenSequence.push(knot.multiplicity);
        }
    }
    nbComplementaryKnots = maxMultOrder - (multiplicityAtOrigin - 1);
    index = 0;
    while (index < nbComplementaryKnots) {
        const multiplicityExcess = nbComplementaryKnots - strictIncSeq.knotMultiplicity(new KnotIndexStrictlyIncreasingSequence(index + 1)) - index;
        if (multiplicityExcess <= 0) {
            nbComplementaryKnots = index + 1;
            break;
        }
        else if (multiplicityExcess < (nbComplementaryKnots - (index + 1))) {
            nbComplementaryKnots = nbComplementaryKnots - multiplicityExcess;
            index++;
        }
        else {
            index++;
        }
    }
    cumulativeMultiplicityFromOrigin = multiplicityAtOrigin;
    for (let i = 0; i < nbComplementaryKnots; i++) {
        if ((i + 1) === lastIndex) {
            knotsOpenSequence.push(lastAbscissa + (lastAbscissa - strictIncSeq.abscissaAtIndex(new KnotIndexStrictlyIncreasingSequence(0))));
        }
        else {
            knotsOpenSequence.push(lastAbscissa + (strictIncSeq.abscissaAtIndex(new KnotIndexStrictlyIncreasingSequence(i + 1)) - strictIncSeq.abscissaAtIndex(new KnotIndexStrictlyIncreasingSequence(0))));
        }
        let multiplicityCurrentKnot = strictIncSeq.knotMultiplicity(new KnotIndexStrictlyIncreasingSequence(i + 1));
        if ((cumulativeMultiplicityFromOrigin + multiplicityCurrentKnot) > maxMultOrder) {
            multiplicityCurrentKnot = maxMultOrder - cumulativeMultiplicityFromOrigin + 1;
        }
        cumulativeMultiplicityFromOrigin += multiplicityCurrentKnot;
        multiplicitiesOpenSequence.push(multiplicityCurrentKnot);
    }
    return { knots: knotsOpenSequence, multiplicities: multiplicitiesOpenSequence };
}

export { prepareStrictlyIncreasingOpenKnotSeqCCfromStrictlyIncreasingPeriodicKnotSeq };