plotboilerplate
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A simple javascript plotting boilerplate for 2d stuff.
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JavaScript
/**
* @author Ikaros Kappler
* @date 2013-08-19
* @modified 2018-08-16 Added closure. Removed the 'IKRS' wrapper.
* @modified 2018-11-20 Added circular auto-adjustment.
* @modified 2018-11-25 Added the point constants to the BezierPath class itself.
* @modified 2018-11-28 Added the locateCurveByStartPoint() function.
* @modified 2018-12-04 Added the toSVGString() function.
* @modified 2019-03-23 Added JSDoc tags.
* @modified 2019-03-23 Changed the fuctions getPoint and getPointAt to match semantics in the Line class.
* @modified 2019-11-18 Fixed the clone function: adjustCircular attribute was not cloned.
* @modified 2019-12-02 Removed some excessive comments.
* @modified 2019-12-04 Fixed the missing obtainHandleLengths behavior in the adjustNeightbourControlPoint function.
* @modified 2020-02-06 Added function locateCurveByEndPoint( Vertex ).
* @modified 2020-02-11 Added 'return this' to the scale(Vertex,number) and to the translate(Vertex) function.
* @modified 2020-03-24 Ported this class from vanilla-JS to Typescript.
* @modified 2020-06-03 Made the private helper function _locateUIndex to a private function.
* @modified 2020-06-03 Added the getBounds() function.
* @modified 2020-07-14 Changed the moveCurvePoint(...,Vertex) to moveCurvePoint(...,XYCoords).
* @modified 2020-07-24 Added the getClosestT(Vertex) function.
* @modified 2020-12-29 Constructor is now private (no explicit use intended).
* @modified 2021-05-25 Added BezierPath.fromReducedList( Array<number> ).
* @modified 2022-01-31 Added `BezierPath.getEvenDistributionVertices(number)`.
* @modified 2022-02-02 Added the `destroy` method.
* @modified 2022-02-02 Cleared the `toSVGString` function (deprecated). Use `drawutilssvg` instead.
* @modified 2023-10-06 Adding the `BezierPath.toPathPoints()` method.
* @modified 2023-10-07 Adding the `BezierPath.fromCurve(CubicBezierCurve)` static function.
* @version 2.6.0
*
* @file BezierPath
* @public
**/
import { Bounds } from "./Bounds";
import { CubicBezierCurve } from "./CubicBezierCurve";
import { UIDGenerator } from "./UIDGenerator";
import { Vertex } from "./Vertex";
/**
* @classdesc A BezierPath class.
*
* This was refactored from an older project.
*
* @requires Bounds
* @requires Vertex
* @requires CubicBezierCurve
* @requires XYCoords
* @requires SVGSerializable
* @requires UID
* @requires UIDGenerator
**/
export class BezierPath {
/**
* The constructor.<br>
* <br>
* This constructor expects a sequence of path points and will approximate
* the location of control points by picking some between the points.<br>
* You should consider just constructing empty paths and then add more curves later using
* the addCurve() function.
*
* @constructor
* @name BezierPath
* @param {Vertex[]} pathPoints - An array of path vertices (no control points).
**/
constructor() {
/**
* Required to generate proper CSS classes and other class related IDs.
**/
this.className = "BezierPath";
/** @constant {number} */
this.START_POINT = 0;
/** @constant {number} */
this.START_CONTROL_POINT = 1;
/** @constant {number} */
this.END_CONTROL_POINT = 2;
/** @constant {number} */
this.END_POINT = 3;
// pathPoints: Array<Vertex> | undefined | null) {
this.uid = UIDGenerator.next();
// if (!pathPoints) {
// pathPoints = [];
// }
this.totalArcLength = 0.0;
// Set this flag to true if you want the first point and
// last point of the path to be auto adjusted, too.
this.adjustCircular = false;
this.bezierCurves = [];
}
/**
* Add a cubic bezier curve to the end of this path.
*
* @method addCurve
* @param {CubicBezierCurve} curve - The curve to be added to the end of the path.
* @instance
* @memberof BezierPath
* @return {void}
**/
addCurve(curve) {
if (curve == null || typeof curve == "undefined")
throw "Cannot add null curve to bézier path.";
this.bezierCurves.push(curve);
if (this.bezierCurves.length > 1) {
curve.startPoint = this.bezierCurves[this.bezierCurves.length - 2].endPoint;
this.adjustSuccessorControlPoint(this.bezierCurves.length - 2, // curveIndex,
true, // obtainHandleLength,
true // updateArcLengths
);
}
else {
this.totalArcLength += curve.getLength();
}
}
/**
* Locate the curve with the given start point (function returns the index).
*
* @method locateCurveByStartPoint
* @param {Vertex} point - The (curve start-) point to look for.
* @instance
* @memberof BezierPath
* @return {number} The curve index or -1 if curve (start-) point not found
**/
locateCurveByStartPoint(point) {
// for( var i in this.bezierCurves ) {
for (var i = 0; i < this.bezierCurves.length; i++) {
if (this.bezierCurves[i].startPoint.equals(point))
return i;
}
return -1;
}
/**
* Locate the curve with the given end point (function returns the index).
*
* @method locateCurveByEndPoint
* @param {Vertex} point - The (curve end-) point to look for.
* @instance
* @memberof BezierPath
* @return {number} The curve index or -1 if curve (end-) point not found
**/
locateCurveByEndPoint(point) {
// for( var i in this.bezierCurves ) {
for (var i = 0; i < this.bezierCurves.length; i++) {
if (this.bezierCurves[i].endPoint.equals(point))
return i;
}
return -1;
}
/**
* Locate the curve with the given start point (function returns the index).
*
* @method locateCurveByStartControlPoint
* @param {Vertex} point - The (curve endt-) point to look for.
* @instance
* @memberof BezierPath
* @return {number} The curve index or -1 if curve (end-) point not found
**/
locateCurveByStartControlPoint(point) {
// for( var i in this.bezierCurves ) {
for (var i = 0; i < this.bezierCurves.length; i++) {
if (this.bezierCurves[i].startControlPoint.equals(point))
return i;
}
return -1;
}
// +---------------------------------------------------------------------------------
// | Locate the curve with the given end control point.
// |
// | @param point:Vertex The point to look for.
// | @return Number The index or -1 if not found.
// +-------------------------------
locateCurveByEndControlPoint(point) {
// for( var i in this.bezierCurves ) {
for (var i = 0; i < this.bezierCurves.length; i++) {
if (this.bezierCurves[i].endControlPoint.equals(point))
return i;
}
return -1;
}
/**
* Get the total length of this path.<br>
* <br>
* Note that the returned value comes from the curve buffer. Unregistered changes
* to the curve points will result in invalid path length values.
*
* @method getLength
* @instance
* @memberof BezierPath
* @return {number} The (buffered) length of the path.
**/
getLength() {
return this.totalArcLength;
}
/**
* This function is internally called whenever the curve or path configuration
* changed. It updates the attribute that stores the path length information.<br>
* <br>
* If you perform any unregistered changes to the curve points you should call
* this function afterwards to update the curve buffer. Not updating may
* result in unexpected behavior.
*
* @method updateArcLengths
* @instance
* @memberof BezierPath
* @return {void}
**/
updateArcLengths() {
this.totalArcLength = 0.0;
for (var i = 0; i < this.bezierCurves.length; i++) {
this.bezierCurves[i].updateArcLengths();
this.totalArcLength += this.bezierCurves[i].getLength();
}
}
/**
* Get the number of curves in this path.
*
* @method getCurveCount
* @instance
* @memberof BezierPath
* @return {number} The number of curves in this path.
**/
getCurveCount() {
return this.bezierCurves.length;
}
/**
* Get the cubic bezier curve at the given index.
*
* @method getCurveAt
* @param {number} index - The curve index from 0 to getCurveCount()-1.
* @instance
* @memberof BezierPath
* @return {CubicBezierCurve} The curve at the specified index.
**/
getCurveAt(curveIndex) {
return this.bezierCurves[curveIndex];
}
/**
* Move the whole bezier path by the given (x,y)-amount.
*
* @method translate
* @param {Vertex} amount - The amount to be added (amount.x and amount.y)
* to each vertex of the curve.
* @instance
* @memberof BezierPath
* @return {BezierPath} this for chaining
**/
translate(amount) {
for (var i = 0; i < this.bezierCurves.length; i++) {
var curve = this.bezierCurves[i];
curve.getStartPoint().add(amount);
curve.getStartControlPoint().add(amount);
curve.getEndControlPoint().add(amount);
}
// Don't forget to translate the last curve's last point
var curve = this.bezierCurves[this.bezierCurves.length - 1];
curve.getEndPoint().add(amount);
this.updateArcLengths();
return this;
}
/**
* Scale the whole bezier path by the given uniform factor.
*
* @method scale
* @param {Vertex} anchor - The scale origin to scale from.
* @param {number} scaleFactor - The scalar to be multiplied with.
* @instance
* @memberof BezierPath
* @return {BezierPath} this for chaining.
**/
scale(anchor, scaleFactor) {
return this.scaleXY({ x: scaleFactor, y: scaleFactor }, anchor);
}
/**
* Scale the whole bezier path by the given (x,y)-factors.
*
* @method scale
* @param {Vertex} anchor - The scale origin to scale from.
* @param {number} amount - The scalar to be multiplied with.
* @instance
* @memberof BezierPath
* @return {BezierPath} this for chaining.
**/
scaleXY(scaleFactors, anchor) {
for (var i = 0; i < this.bezierCurves.length; i++) {
var curve = this.bezierCurves[i];
curve.getStartPoint().scaleXY(scaleFactors, anchor);
curve.getStartControlPoint().scaleXY(scaleFactors, anchor);
curve.getEndControlPoint().scaleXY(scaleFactors, anchor);
// Do NOT scale the end point here!
// Don't forget that the curves are connected and on curve's end point
// the the successor's start point (same instance)!
}
// Finally move the last end point (was not scaled yet)
if (this.bezierCurves.length > 0 && !this.adjustCircular) {
this.bezierCurves[this.bezierCurves.length - 1].getEndPoint().scaleXY(scaleFactors, anchor);
}
this.updateArcLengths();
return this;
}
/**
* Rotate the whole bezier path around a point..
*
* @method rotate
* @param {Vertex} angle - The angle to rotate this path by.
* @param {Vertex} center - The rotation center.
* @instance
* @memberof BezierPath
* @return {void}
**/
rotate(angle, center) {
for (var i = 0; i < this.bezierCurves.length; i++) {
var curve = this.bezierCurves[i];
curve.getStartPoint().rotate(angle, center);
curve.getStartControlPoint().rotate(angle, center);
curve.getEndControlPoint().rotate(angle, center);
// Do NOT rotate the end point here!
// Don't forget that the curves are connected and on curve's end point
// the the successor's start point (same instance)!
}
// Finally move the last end point (was not scaled yet)
if (this.bezierCurves.length > 0 && !this.adjustCircular) {
this.bezierCurves[this.bezierCurves.length - 1].getEndPoint().rotate(angle, center);
}
}
/**
* Get the 't' position on this curve with the minimal distance to point p.
*
* @param {Vertex} p - The point to find the closest curve point for.
* @return {number} A value t with 0.0 <= t <= 1.0.
**/
getClosestT(p) {
// Find the spline to extract the value from
var minIndex = -1;
var minDist = 0.0;
var dist = 0.0;
var curveT = 0.0;
var uMin = 0.0;
var u = 0.0;
for (var i = 0; i < this.bezierCurves.length; i++) {
curveT = this.bezierCurves[i].getClosestT(p);
dist = this.bezierCurves[i].getPointAt(curveT).distance(p);
if (minIndex == -1 || dist < minDist) {
minIndex = i;
minDist = dist;
uMin = u + curveT * this.bezierCurves[i].getLength();
}
u += this.bezierCurves[i].getLength();
}
return Math.max(0.0, Math.min(1.0, uMin / this.totalArcLength));
}
/**
* Get the point on the bézier path at the given relative path location.
*
* @method getPoint
* @param {number} u - The relative path position: <pre>0 <= u <= this.getLength()</pre>
* @instance
* @memberof BezierPath
* @return {Vertex} The point at the relative path position.
**/
getPoint(u) {
if (u < 0 || u > this.totalArcLength) {
console.warn("[BezierPath.getPoint(u)] u is out of bounds: " + u + ".");
u = Math.min(this.totalArcLength, Math.max(u, 0));
}
// Find the spline to extract the value from
var i = 0;
var uTemp = 0.0;
while (i < this.bezierCurves.length && uTemp + this.bezierCurves[i].getLength() < u) {
uTemp += this.bezierCurves[i].getLength();
i++;
}
// if u == arcLength
// -> i is max
if (i >= this.bezierCurves.length)
return this.bezierCurves[this.bezierCurves.length - 1].getEndPoint().clone();
var bCurve = this.bezierCurves[i];
var relativeU = u - uTemp;
return bCurve.getPoint(relativeU);
}
/**
* Get the point on the bézier path at the given path fraction.
*
* @method getPointAt
* @param {number} t - The absolute path position: <pre>0.0 <= t <= 1.0</pre>
* @instance
* @memberof BezierPath
* @return {Vertex} The point at the absolute path position.
**/
getPointAt(t) {
return this.getPoint(t * this.totalArcLength);
}
/**
* Get the tangent of the bézier path at the given path fraction.<br>
* <br>
* Note that the returned vector is not normalized.
*
* @method getTangentAt
* @param {number} t - The absolute path position: <pre>0.0 <= t <= 1.0</pre>
* @instance
* @memberof BezierPath
* @return {Vertex} The tangent vector at the absolute path position.
**/
getTangentAt(t) {
return this.getTangent(t * this.totalArcLength);
}
/**
* Get the tangent of the bézier path at the given path location.<br>
* <br>
* Note that the returned vector is not normalized.
*
* @method getTangent
* @param {number} u - The relative path position: <pre>0 <= u <= getLength()</pre>
* @instance
* @memberof BezierPath
* @return {Vertex} The tangent vector at the relative path position.
**/
getTangent(u) {
if (u < 0 || u > this.totalArcLength) {
console.warn("[BezierPath.getTangent(u)] u is out of bounds: " + u + ".");
// return undefined;
u = Math.min(this.totalArcLength, Math.max(0, u));
}
// Find the spline to extract the value from
var i = 0;
var uTemp = 0.0;
while (i < this.bezierCurves.length && uTemp + this.bezierCurves[i].getLength() < u) {
uTemp += this.bezierCurves[i].getLength();
i++;
}
var bCurve = this.bezierCurves[i];
var relativeU = u - uTemp;
return bCurve.getTangent(relativeU);
}
/**
* Get the perpendicular of the bézier path at the given absolute path location (fraction).<br>
* <br>
* Note that the returned vector is not normalized.
*
* @method getPerpendicularAt
* @param {number} t - The absolute path position: <pre>0.0 <= t <= 1.0</pre>
* @instance
* @memberof BezierPath
* @return {Vertex} The perpendicluar vector at the absolute path position.
**/
getPerpendicularAt(t) {
return this.getPerpendicular(t * this.totalArcLength);
}
/**
* Get the perpendicular of the bézier path at the given relative path location.<br>
* <br>
* Note that the returned vector is not normalized.
*
* @method getPerpendicular
* @param {number} u - The relative path position: <pre>0 <= u <= getLength()</pre>
* @instance
* @memberof BezierPath
* @return {Vertex} The perpendicluar vector at the relative path position.
**/
getPerpendicular(u) {
if (u < 0 || u > this.totalArcLength) {
console.log("[BezierPath.getPerpendicular(u)] u is out of bounds: " + u + ".");
u = Math.min(this.totalArcLength, Math.max(0, u));
}
// Find the spline to extract the value from
var uResult = BezierPath._locateUIndex(this, u);
var bCurve = this.bezierCurves[uResult.i];
var relativeU = u - uResult.uPart;
return bCurve.getPerpendicular(relativeU);
}
/**
* This is a helper function to locate the curve index for a given
* absolute path position u.
*
* I decided to put this into privat scope as it is really specific. Maybe
* put this into a utils wrapper.
*
* Returns:
* - {number} i - the index of the containing curve.
* - {number} uPart - the absolute curve length sum (length from the beginning to u, should equal u itself).
* - {number} uBefore - the absolute curve length for all segments _before_ the matched curve (usually uBefore <= uPart).
**/
static _locateUIndex(path, u) {
var i = 0;
var uTemp = 0.0;
var uBefore = 0.0;
while (i < path.bezierCurves.length && uTemp + path.bezierCurves[i].getLength() < u) {
uTemp += path.bezierCurves[i].getLength();
if (i + 1 < path.bezierCurves.length)
uBefore += path.bezierCurves[i].getLength();
i++;
}
return { i: i, uPart: uTemp, uBefore: uBefore };
}
/**
* Get a specific sub path from this path. The start and end position are specified by
* ratio number in [0..1].
*
* 0.0 is at the beginning of the path.
* 1.0 is at the end of the path.
*
* Values below 0 or beyond 1 are cropped down to the [0..1] interval.
*
* startT > endT is allowed, the returned sub path will have inverse direction then.
*
* @method getSubPathAt
* @param {number} startT - The start position of the sub path.
* @param {number} endT - The end position of the sub path.
* @instance
* @memberof BezierPath
* @return {BezierPath} The desired sub path in the bounds [startT..endT].
**/
getSubPathAt(startT, endT) {
startT = Math.max(0, startT);
endT = Math.min(1.0, endT);
let startU = startT * this.totalArcLength;
let endU = endT * this.totalArcLength;
var uStartResult = BezierPath._locateUIndex(this, startU); // { i:int, uPart:float, uBefore:float }
var uEndResult = BezierPath._locateUIndex(this, endU); // { i:int, uPart:float, uBefore:float }
var firstT = (startU - uStartResult.uBefore) / this.bezierCurves[uStartResult.i].getLength();
if (uStartResult.i == uEndResult.i) {
// Subpath begins and ends in the same path segment (just get a simple sub curve from that path element).
var lastT = (endU - uEndResult.uBefore) / this.bezierCurves[uEndResult.i].getLength();
var firstCurve = this.bezierCurves[uStartResult.i].getSubCurveAt(firstT, lastT);
return BezierPath.fromArray([firstCurve]);
}
else {
var curves = [];
if (uStartResult.i > uEndResult.i) {
// Back to front direction
var firstCurve = this.bezierCurves[uStartResult.i].getSubCurveAt(firstT, 0.0);
curves.push(firstCurve);
for (var i = uStartResult.i - 1; i > uEndResult.i; i--) {
curves.push(this.bezierCurves[i].clone().reverse());
}
var lastT = (endU - uEndResult.uBefore) / this.bezierCurves[uEndResult.i].getLength();
curves.push(this.bezierCurves[uEndResult.i].getSubCurveAt(1.0, lastT));
}
else {
// Front to back direction
var firstCurve = this.bezierCurves[uStartResult.i].getSubCurveAt(firstT, 1.0);
curves.push(firstCurve);
for (var i = uStartResult.i + 1; i < uEndResult.i && i < this.bezierCurves.length; i++) {
curves.push(this.bezierCurves[i].clone());
}
var lastT = (endU - uEndResult.uBefore) / this.bezierCurves[uEndResult.i].getLength();
curves.push(this.bezierCurves[uEndResult.i].getSubCurveAt(0, lastT));
}
return BezierPath.fromArray(curves);
}
}
/**
* This function moves the addressed curve point (or control point) with
* keeping up the path's curve integrity.<br>
* <br>
* Thus is done by moving neighbour- and control- points as needed.
*
* @method moveCurvePoint
* @param {number} curveIndex - The curve index to move a point from.
* @param {number} pointID - One of the curve's four point IDs (START_POINT,
* START_CONTROL_POINT, END_CONTRO_POINT or END_POINT).
* @param {XYCoords} moveAmount - The amount to move the addressed vertex by.
* @instance
* @memberof BezierPath
* @return {void}
**/
moveCurvePoint(curveIndex, pointID, moveAmount) {
var bCurve = this.getCurveAt(curveIndex);
bCurve.moveCurvePoint(pointID, moveAmount, true, // move control point, too
true // updateArcLengths
);
// If inner point and NOT control point
// --> move neightbour
if (pointID == this.START_POINT && (curveIndex > 0 || this.adjustCircular)) {
// Set predecessor's control point!
var predecessor = this.getCurveAt(curveIndex - 1 < 0 ? this.bezierCurves.length + (curveIndex - 1) : curveIndex - 1);
predecessor.moveCurvePoint(this.END_CONTROL_POINT, moveAmount, true, // move control point, too
false // updateArcLengths
);
}
else if (pointID == this.END_POINT && (curveIndex + 1 < this.bezierCurves.length || this.adjustCircular)) {
// Set successcor
var successor = this.getCurveAt((curveIndex + 1) % this.bezierCurves.length);
successor.moveCurvePoint(this.START_CONTROL_POINT, moveAmount, true, // move control point, too
false // updateArcLengths
);
}
else if (pointID == this.START_CONTROL_POINT && curveIndex > 0) {
this.adjustPredecessorControlPoint(curveIndex, true, // obtain handle length?
false // update arc lengths
);
}
else if (pointID == this.END_CONTROL_POINT && curveIndex + 1 < this.getCurveCount()) {
this.adjustSuccessorControlPoint(curveIndex, true, // obtain handle length?
false // update arc lengths
);
}
// Don't forget to update the arc lengths!
// Note: this can be optimized as only two curves have changed their lengths!
this.updateArcLengths();
}
/**
* This helper function adjusts the given point's predecessor's control point.
*
* @method adjustPredecessorControlPoint
* @param {number} curveIndex - The curve index to move a point from.
* @param {boolean} obtainHandleLength - Moves the point with keeping the original handle length.
* @param {boolean} updateArcLength - The amount to move the addressed vertex by.
* @instance
* @private
* @memberof BezierPath
* @return {void}
**/
adjustPredecessorControlPoint(curveIndex, obtainHandleLength, updateArcLengths) {
if (!this.adjustCircular && curveIndex <= 0)
return; // false;
var mainCurve = this.getCurveAt(curveIndex);
var neighbourCurve = this.getCurveAt(curveIndex - 1 < 0 ? this.getCurveCount() + (curveIndex - 1) : curveIndex - 1);
BezierPath.adjustNeighbourControlPoint(mainCurve, neighbourCurve, mainCurve.getStartPoint(), // the reference point
mainCurve.getStartControlPoint(), // the dragged control point
neighbourCurve.getEndPoint(), // the neighbour's point
neighbourCurve.getEndControlPoint(), // the neighbour's control point to adjust
obtainHandleLength, updateArcLengths);
}
/**
* This helper function adjusts the given point's successor's control point.
*
* @method adjustSuccessorControlPoint
* @param {number} curveIndex - The curve index to move a point from.
* @param {boolean} obtainHandleLength - Moves the point with keeping the original handle length.
* @param {boolean} updateArcLength - The amount to move the addressed vertex by.
* @instance
* @private
* @memberof BezierPath
* @return {void}
**/
adjustSuccessorControlPoint(curveIndex, obtainHandleLength, updateArcLengths) {
if (!this.adjustCircular && curveIndex + 1 > this.getCurveCount())
return; // false;
var mainCurve = this.getCurveAt(curveIndex);
var neighbourCurve = this.getCurveAt((curveIndex + 1) % this.getCurveCount());
/* return */ BezierPath.adjustNeighbourControlPoint(mainCurve, neighbourCurve, mainCurve.getEndPoint(), // the reference point
mainCurve.getEndControlPoint(), // the dragged control point
neighbourCurve.getStartPoint(), // the neighbour's point
neighbourCurve.getStartControlPoint(), // the neighbour's control point to adjust
obtainHandleLength, updateArcLengths);
}
/**
* This helper function adjusts the given point's successor's control point.
*
* @method adjustNeighbourControlPoint
* @param {CubicBezierCurve} mainCurve
* @param {CubicBezierCurve} neighbourCurve
* @param {Vertex} mainPoint
* @param {Vertex} mainControlPoint
* @param {Vertex} neighbourPoint
* @param {Vertex} neighbourControlPoint
* @param {boolean} obtainHandleLengths
* @param {boolean} updateArcLengths
* @instance
* @private
* @memberof BezierPath
* @return {void}
**/
static adjustNeighbourControlPoint(_mainCurve, // TODO: remove param
neighbourCurve, mainPoint, mainControlPoint, neighbourPoint, neighbourControlPoint, obtainHandleLengths, _updateArcLengths // TODO: remove param
) {
// Calculate start handle length
var mainHandleBounds = new Vertex(mainControlPoint.x - mainPoint.x, mainControlPoint.y - mainPoint.y);
var neighbourHandleBounds = new Vertex(neighbourControlPoint.x - neighbourPoint.x, neighbourControlPoint.y - neighbourPoint.y);
var mainHandleLength = Math.sqrt(Math.pow(mainHandleBounds.x, 2) + Math.pow(mainHandleBounds.y, 2));
var neighbourHandleLength = Math.sqrt(Math.pow(neighbourHandleBounds.x, 2) + Math.pow(neighbourHandleBounds.y, 2));
if (mainHandleLength <= 0.1)
return; // no secure length available for division? What about zoom? Use EPSILON?
// Just invert the main handle (keep length or not?
if (obtainHandleLengths) {
neighbourControlPoint.set(neighbourPoint.x - mainHandleBounds.x * (neighbourHandleLength / mainHandleLength), neighbourPoint.y - mainHandleBounds.y * (neighbourHandleLength / mainHandleLength));
}
else {
neighbourControlPoint.set(neighbourPoint.x - mainHandleBounds.x, neighbourPoint.y - mainHandleBounds.y);
}
neighbourCurve.updateArcLengths();
}
/**
* Get the bounds of this Bézier path.
*
* Note the the curves' underlyung segment buffers are used to determine the bounds. The more
* elements the segment buffers have, the more precise the returned bounds will be.
*
* @return {Bounds} The bounds of this Bézier path.
**/
getBounds() {
const min = new Vertex(Number.POSITIVE_INFINITY, Number.POSITIVE_INFINITY);
const max = new Vertex(Number.NEGATIVE_INFINITY, Number.NEGATIVE_INFINITY);
var b;
for (var i = 0; i < this.bezierCurves.length; i++) {
b = this.bezierCurves[i].getBounds();
min.x = Math.min(min.x, b.min.x);
min.y = Math.min(min.y, b.min.y);
max.x = Math.max(max.x, b.max.x);
max.y = Math.max(max.y, b.max.y);
}
return new Bounds(min, max);
}
/**
* Get n 'equally' distributed vertices along this Bézier path.
*
* As the changing curvature of the B slines makes prediction of distances difficult, the
* returned vertices' distances are only relatively equal:
* - the distance grows where curvature is large.
* - the distance shrinks where curvature is small.
*
* Only the distance mean of all consecutive is 1/n-th of the total arc length.
*
* Usually this approximation is good enough for most use cases.
*
* @param {number} pointCount - (must be at least 2) The number of desired points (start and end point included).
* @return {Array<Vertex>}
*/
getEvenDistributionVertices(pointCount) {
if (pointCount < 2) {
throw new Error("pointCount must be larger than one; is " + pointCount + ".");
}
const result = [];
if (this.bezierCurves.length === 0) {
return result;
}
// Fetch and add the start point from the source polygon
var polygonPoint = new Vertex(this.bezierCurves[0].startPoint);
result.push(polygonPoint);
// if (this.bezierCurves.length === 1) {
// return result;
// }
const perimeter = this.totalArcLength;
const stepSize = perimeter / (pointCount - 1);
const n = this.bezierCurves.length;
let curveIndex = 0;
let segmentLength = this.bezierCurves[0].arcLength;
let curSegmentU = stepSize;
let i = 1;
while (i < pointCount && curveIndex < n) {
// Check if next eq point is inside this segment
if (curSegmentU < segmentLength) {
var newPoint = this.bezierCurves[curveIndex].getPoint(curSegmentU);
result.push(newPoint);
curSegmentU += stepSize;
i++;
}
else {
curveIndex++;
curSegmentU = curSegmentU - segmentLength;
segmentLength = curveIndex < n ? this.bezierCurves[curveIndex].arcLength : 0;
}
}
result.push(new Vertex(this.bezierCurves[n - 1].endPoint));
return result;
}
/**
* Clone this BezierPath (deep clone).
*
* @method clone
* @instance
* @memberof BezierPath
* @return {BezierPath}
**/
clone() {
var path = new BezierPath(); // undefined);
for (var i = 0; i < this.bezierCurves.length; i++) {
path.bezierCurves.push(this.bezierCurves[i].clone());
// Connect splines
if (i > 0)
path.bezierCurves[i - 1].endPoint = path.bezierCurves[i].startPoint;
}
path.updateArcLengths();
path.adjustCircular = this.adjustCircular;
return path;
}
/**
* Compare this and the passed Bézier path.
*
* @method equals
* @param {BezierPath} path - The pass to compare with.
* @instance
* @memberof BezierPath
* @return {boolean}
**/
equals(path) {
if (!path)
return false;
// Check if path contains the credentials
if (!path.bezierCurves)
return false;
if (typeof path.bezierCurves.length == "undefined")
return false;
if (path.bezierCurves.length != this.bezierCurves.length)
return false;
for (var i = 0; i < this.bezierCurves.length; i++) {
if (!this.bezierCurves[i].equals(path.bezierCurves[i]))
return false;
}
return true;
}
/**
* This function should invalidate any installed listeners and invalidate this object.
* After calling this function the object might not hold valid data any more and
* should not be used.
*
* @method destroy
* @instance
* @memberof BezierPath
*/
destroy() {
for (var i = 0; i < this.bezierCurves.length; i++) {
this.bezierCurves[i].destroy();
}
this.isDestroyed = true;
}
/**
* Convert this path to an array of path points that can be drawn by the default DrawLib
* implementations.
*
* @method toPathPoints
* @instance
* @memberof BezierPath
* @return {Array<XYCoords>}
*/
toPathPoints() {
if (this.bezierCurves.length === 0) {
return [];
}
if (this.bezierCurves.length === 1) {
return [
this.bezierCurves[0].startPoint,
this.bezierCurves[0].startControlPoint,
this.bezierCurves[0].endControlPoint,
this.bezierCurves[0].endPoint
];
}
const arr = [];
arr.push(this.bezierCurves[0].startPoint);
arr.push(this.bezierCurves[0].startControlPoint);
for (var i = 1; i < this.bezierCurves.length; i++) {
arr.push(this.bezierCurves[i - 1].endControlPoint);
arr.push(this.bezierCurves[i - 1].endPoint);
arr.push(this.bezierCurves[i].startPoint);
arr.push(this.bezierCurves[i].startControlPoint);
}
arr.push(this.bezierCurves[0].endControlPoint);
arr.push(this.bezierCurves[0].endPoint);
return arr;
}
/**
* Create a JSON string representation of this bézier curve.
*
* @method toJSON
* @param {boolean} prettyFormat - If true then the function will add line breaks.
* @instance
* @memberof BezierPath
* @return {string} The JSON string.
**/
toJSON(prettyFormat) {
var buffer = [];
buffer.push("["); // array begin
for (var i = 0; i < this.bezierCurves.length; i++) {
if (i > 0)
buffer.push(",");
if (prettyFormat)
buffer.push("\n\t");
else
buffer.push(" ");
buffer.push(this.bezierCurves[i].toJSON(prettyFormat));
}
if (this.bezierCurves.length != 0)
buffer.push(" ");
buffer.push("]"); // array end
return buffer.join(""); // Convert to string, with empty separator.
}
/**
* Parse a BezierPath from the given JSON string.
*
* @method fromJSON
* @param {string} jsonString - The string with the JSON data.
* @throw An error if the string is not JSON or does not contain a bezier path object.
* @static
* @memberof BezierPath
* @return {BezierPath} The parsed bezier path instance.
**/
static fromJSON(jsonString) {
var obj = JSON.parse(jsonString);
return BezierPath.fromArray(obj);
}
/**
* Construct a new path with a single curve. Adding more curves is always possible.
*
* @method fromCurve
* @param {CubicBezierCurve} curve - The curve to construct a new path from.
* @static
* @memberof BezierPath
* @return {BezierPath} The constructed bezier path instance.
*/
static fromCurve(curve) {
const path = new BezierPath(); // []);
path.addCurve(curve);
return path;
}
/**
* Create a BezierPath instance from the given array.
*
* @method fromArray
* @param {Vertex[][]} arr - A two-dimensional array containing the bezier path vertices.
* @throw An error if the array does not contain proper bezier path data.
* @static
* @memberof BezierPath
* @return {BezierPath} The bezier path instance retrieved from the array data.
**/
static fromArray(obj) {
if (!Array.isArray(obj)) {
throw "[BezierPath.fromArray] Passed object must be an array.";
}
const arr = obj; // FORCE?
if (arr.length < 1) {
throw "[BezierPath.fromArray] Passed array must contain at least one bezier curve (has " + arr.length + ").";
}
// Create an empty bezier path
var bPath = new BezierPath(); // undefined);
var lastCurve = null;
for (var i = 0; i < arr.length; i++) {
// Convert object (or array?) to bezier curve
var bCurve;
if (CubicBezierCurve.isInstance(arr[i])) {
bCurve = arr[i].clone();
}
else if (0 in arr[i] && 1 in arr[i] && 2 in arr[i] && 3 in arr[i]) {
if (!arr[i][0] || !arr[i][1] || !arr[i][2] || !arr[i][3])
throw "Cannot convert path data to BezierPath instance. At least one element is undefined (index=" + i + "): " + arr[i];
bCurve = CubicBezierCurve.fromArray(arr[i]);
}
else {
bCurve = CubicBezierCurve.fromObject(arr[i]);
}
// Set curve start point?
// (avoid duplicate point instances!)
if (lastCurve)
bCurve.startPoint = lastCurve.endPoint;
// Add to path's internal list
bPath.bezierCurves.push(bCurve);
// bPath.totalArcLength += bCurve.getLength();
lastCurve = bCurve;
}
bPath.updateArcLengths();
// Bezier segments added. Done
return bPath;
}
/**
* This function converts the bezier path into a string containing
* integer values only.
* The points' float values are rounded to 1 digit after the comma.
*
* The returned string represents a JSON array (with leading '[' and
* trailing ']', the separator is ',').
*
* @method toReducedListRepresentation
* @param {number} digits - The number of digits to be used after the comma '.'.
* @instance
* @memberof BezierPath
* @return {string} The reduced list representation of this path.
**/
toReducedListRepresentation(digits) {
if (typeof digits == "undefined")
digits = 1;
var buffer = [];
buffer.push("["); // array begin
for (var i = 0; i < this.bezierCurves.length; i++) {
var curve = this.bezierCurves[i];
buffer.push(curve.getStartPoint().x.toFixed(digits));
buffer.push(",");
buffer.push(curve.getStartPoint().y.toFixed(digits));
buffer.push(",");
buffer.push(curve.getStartControlPoint().x.toFixed(digits));
buffer.push(",");
buffer.push(curve.getStartControlPoint().y.toFixed(digits));
buffer.push(",");
buffer.push(curve.getEndControlPoint().x.toFixed(digits));
buffer.push(",");
buffer.push(curve.getEndControlPoint().y.toFixed(digits));
buffer.push(",");
}
if (this.bezierCurves.length != 0) {
var curve = this.bezierCurves[this.bezierCurves.length - 1];
buffer.push(curve.getEndPoint().x.toFixed(digits));
buffer.push(",");
buffer.push(curve.getEndPoint().y.toFixed(digits));
}
buffer.push("]"); // array end
return buffer.join(""); // Convert to string, with empty separator.
}
/**
* Parse a BezierPath instance from the reduced list representation.<br>
* <br>
* The passed string must represent a JSON array containing numbers only.
*
* @method fromReducedListRepresentation
* @param {string} listJSON - The number of digits to be used after the floating point.
* @throw An error if the string is malformed.
* @instance
* @memberof BezierPath
* @return {BezierPath} The bezier path instance retrieved from the string.
**/
static fromReducedListRepresentation(listJSON, adjustCircular) {
// Parse the array
var pointArray = JSON.parse(listJSON);
if (!pointArray.length) {
console.log("Cannot parse bezier path from non-array object nor from empty point list.");
throw "Cannot parse bezier path from non-array object nor from empty point list.";
}
if (pointArray.length < 8) {
console.log("Cannot build bezier path. The passed array must contain at least 8 elements (numbers).");
throw "Cannot build bezier path. The passed array must contain at least 8 elements (numbers).";
}
return BezierPath.fromReducedList(pointArray, adjustCircular);
}
/**
* Convert a reduced list representation (array of numeric coordinates) to a BezierPath instance.
*
* The array's length must be 6*n + 2:
* - [sx, sy, scx, scy, ecx, ecy, ... , ex, ey ]
* | | | |
* +--- sequence of curves --------+ +-end-+
*
* @param {number[]} pointArray
* @returns BezierPath
*/
static fromReducedList(pointArray, adjustCircular) {
// Convert to object
var bezierPath = new BezierPath(); // null); // No points yet
var startPoint = new Vertex();
var startControlPoint;
var endControlPoint;
var endPoint;
var i = 0;
do {
if (i == 0) {
// firstStartPoint =
startPoint = new Vertex(pointArray[i], pointArray[i + 1]);
}
startControlPoint = new Vertex(pointArray[i + 2], pointArray[i + 3]);
endControlPoint = new Vertex(pointArray[i + 4], pointArray[i + 5]);
// if (i + 8 >= pointArray.length) {
// endPoint = firstStartPoint;
// } else {
endPoint = new Vertex(pointArray[i + 6], pointArray[i + 7]);
// }
var bCurve = new CubicBezierCurve(startPoint, endPoint, startControlPoint, endControlPoint);
bezierPath.bezierCurves.push(bCurve);
startPoint = endPoint;
i += 6;
} while (i + 2 < pointArray.length);
bezierPath.adjustCircular = adjustCircular !== null && adjustCircular !== void 0 ? adjustCircular : false;
if (adjustCircular) {
bezierPath.bezierCurves[bezierPath.bezierCurves.length - 1].endPoint = bezierPath.bezierCurves[0].startPoint;
}
bezierPath.updateArcLengths();
return bezierPath;
}
}
// +---------------------------------------------------------------------------------
// | These constants equal the values from CubicBezierCurve.
// +-------------------------------
/** @constant {number} */
BezierPath.START_POINT = 0;
/** @constant {number} */
BezierPath.START_CONTROL_POINT = 1;
/** @constant {number} */
BezierPath.END_CONTROL_POINT = 2;
/** @constant {number} */
BezierPath.END_POINT = 3;
//# sourceMappingURL=BezierPath.js.map