@osbjs/osbjs/dist/Beatmap/Curves/CatmullCurve.js

a minimalist osu! storyboarding framework

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.CatmullCurve = void 0;
const Math_1 = require("../../Math");
const Curve_1 = require("./Curve");
class CatmullCurve extends Curve_1.Curve {
    constructor(points, precision) {
        super();
        this.points = points;
        this.precision = precision;
        this.startPosition = points[0];
        this.endPosition = points[points.length - 1];
        this.distancePositions = [];
        this.length = this._initLength();
    }
    getPositionAtProgress(t) {
        return this.getPositionAtDistance(this.precision * t);
    }
    getPositionAtDelta(delta) {
        return this.getPositionAtDistance(delta * this.length);
    }
    getPositionAtDistance(distance) {
        let previousDistance = 0.0;
        let previousPosition = this.startPosition;
        let nextDistance = this.length;
        let nextPosition = this.endPosition;
        let i = 0;
        while (i < this.distancePositions.length) {
            let distancePosition = this.distancePositions[i];
            if (distancePosition.distance > distance)
                break;
            previousDistance = distancePosition.distance;
            previousPosition = distancePosition.position;
            i++;
        }
        if (i < this.distancePositions.length - 1) {
            let distancePosition = this.distancePositions[i + 1];
            nextDistance = distancePosition.distance;
            nextPosition = distancePosition.position;
        }
        let delta = (distance - previousDistance) / (nextDistance - previousDistance);
        let prevNext = Math_1.Vector2.sub(nextPosition, previousPosition);
        return Math_1.Vector2.add(previousPosition, Math_1.Vector2.multiplyScalar(prevNext, delta));
    }
    _initLength() {
        let precision = this.points.length > 2 ? this.precision : 0;
        let distance = 0.0;
        let linePrecision = precision / this.points.length;
        let previousPosition = this.startPosition;
        for (let lineIndex = 0; lineIndex < this.points.length - 1; ++lineIndex) {
            for (let i = 1; i <= linePrecision; ++i) {
                let delta = i / (linePrecision + 1);
                let p1 = lineIndex > 0 ? this.points[lineIndex - 1] : this.points[lineIndex];
                let p2 = this.points[lineIndex];
                let p3 = this.points[lineIndex + 1];
                let p4 = lineIndex < this.points.length - 2 ? this.points[lineIndex + 2] : this.points[lineIndex + 1];
                let nextPosition = this._getPositionAtDelta(p1, p2, p3, p4, delta);
                let prevNext = Math_1.Vector2.sub(nextPosition, previousPosition);
                distance += prevNext.length();
                this.distancePositions.push({ distance, position: nextPosition });
                previousPosition = nextPosition;
            }
        }
        let prevEnd = Math_1.Vector2.sub(this.endPosition, previousPosition);
        distance += prevEnd.length();
        return distance;
    }
    _getPointPositionAtDelta(p1, p2, p3, p4, delta) {
        return (0.5 *
            ((-p1 + 3 * p2 - 3 * p3 + p4) * delta * delta * delta + (2 * p1 - 5 * p2 + 4 * p3 - p4) * delta * delta + (-p1 + p3) * delta + 2 * p2));
    }
    _getPositionAtDelta(p1, p2, p3, p4, delta) {
        const result = new Math_1.Vector2();
        result.x = this._getPointPositionAtDelta(p1.x, p2.x, p3.x, p4.x, delta);
        result.y = this._getPointPositionAtDelta(p1.y, p2.y, p3.y, p4.y, delta);
        return result;
    }
}
exports.CatmullCurve = CatmullCurve;