plotboilerplate
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A simple javascript plotting boilerplate for 2d stuff.
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JavaScript
"use strict";
/**
* @author Ikaros Kappler
* @date 2013-08-15
* @modified 2018-08-16 Added a closure. Removed the wrapper class 'IKRS'. Replaced class THREE.Vector2 by Vertex class.
* @modified 2018-11-19 Added the fromArray(Array) function.
* @modified 2018-11-28 Added the locateCurveByPoint(Vertex) function.
* @modified 2018-12-04 Added the toSVGPathData() function.
* @modified 2019-03-20 Added JSDoc tags.
* @modified 2019-03-23 Changed the signatures of getPoint, getPointAt and getTangent (!version 2.0).
* @modified 2019-12-02 Fixed the updateArcLength function. It used the wrong pointAt function (was renamed before).
* @modified 2020-02-06 Added the getSubCurveAt(number,number) function.
* @modified 2020-02-06 Fixed a serious bug in the arc lenght calculation (length was never reset, urgh).
* @modified 2020-02-07 Added the isInstance(any) function.
* @modified 2020-02-10 Added the reverse() function.
* @modified 2020-02-10 Fixed the translate(...) function (returning 'this' was missing).
* @modified 2020-03-24 Ported this class from vanilla JS to Typescript.
* @modified 2020-06-03 Added the getBounds() function.
* @modified 2020-07-14 Changed the moveCurvePoint(...,Vertex) to moveCurvePoint(...,XYCoords), which is more generic.
* @modified 2020-07-24 Added the getClosestT function and the helper function locateIntervalByDistance(...).
* @modified 2021-01-20 Added UID.
* @modified 2022-02-02 Added the `destroy` method.
* @modified 2022-02-02 Cleared the `toSVGPathData` function (deprecated). Use `drawutilssvg` instead.
* @modified 2022-10-17 The `CubicBezierCurve` class now implements the new `PathSegment` interface.
* @modified 2023-09-30 Added the function `CubicbezierCurve.getSubCurve(number,number)` – similar to `getSubCurveAt(...)` but with absolute position parameters.
* @modified 2023-10-07 Added the `trimEnd`, `trimEndAt`, `trimStart`, `trimStartAt` methods.
* @version 2.8.0
*
* @file CubicBezierCurve
* @public
**/
Object.defineProperty(exports, "__esModule", { value: true });
exports.CubicBezierCurve = void 0;
var Bounds_1 = require("./Bounds");
var UIDGenerator_1 = require("./UIDGenerator");
var Vertex_1 = require("./Vertex");
var Vector_1 = require("./Vector");
/**
* @classdesc A refactored cubic bezier curve class.
*
* @requires Bounds
* @requires Vertex
* @requires Vector
* @requires XYCoords
* @requires UID
* @requires UIDGenerator
*/
var CubicBezierCurve = /** @class */ (function () {
/**
* The constructor.
*
* @constructor
* @name CubicBezierCurve
* @param {Vertex} startPoint - The Bézier curve's start point.
* @param {Vertex} endPoint - The Bézier curve's end point.
* @param {Vertex} startControlPoint - The Bézier curve's start control point.
* @param {Vertex} endControlPoint - The Bézier curve's end control point.
**/
function CubicBezierCurve(startPoint, endPoint, startControlPoint, endControlPoint) {
/** @constant {number} */
this.START_POINT = CubicBezierCurve.START_POINT;
/** @constant {number} */
this.START_CONTROL_POINT = CubicBezierCurve.START_CONTROL_POINT;
/** @constant {number} */
this.END_CONTROL_POINT = CubicBezierCurve.END_CONTROL_POINT;
/** @constant {number} */
this.END_POINT = CubicBezierCurve.END_POINT;
this.uid = UIDGenerator_1.UIDGenerator.next();
this.startPoint = startPoint;
this.startControlPoint = startControlPoint;
this.endPoint = endPoint;
this.endControlPoint = endControlPoint;
this.curveIntervals = 30;
// An array of vertices
this.segmentCache = [];
// An array of floats
this.segmentLengths = [];
// float
// this.arcLength = null;
this.updateArcLengths();
}
/**
* Move the given curve point (the start point, end point or one of the two
* control points).
*
* @method moveCurvePoint
* @param {number} pointID - The numeric identicator of the point to move. Use one of the four eBezierPoint constants.
* @param {XYCoords} moveAmount - The amount to move the specified point by.
* @param {boolean} moveControlPoint - Move the control points along with their path point (if specified point is a path point).
* @param {boolean} updateArcLengths - Specifiy if the internal arc segment buffer should be updated.
* @instance
* @memberof CubicBezierCurve
* @return {void}
**/
CubicBezierCurve.prototype.moveCurvePoint = function (pointID, moveAmount, moveControlPoint, updateArcLengths) {
if (pointID == this.START_POINT) {
this.getStartPoint().add(moveAmount);
if (moveControlPoint)
this.getStartControlPoint().add(moveAmount);
}
else if (pointID == this.START_CONTROL_POINT) {
this.getStartControlPoint().add(moveAmount);
}
else if (pointID == this.END_CONTROL_POINT) {
this.getEndControlPoint().add(moveAmount);
}
else if (pointID == this.END_POINT) {
this.getEndPoint().add(moveAmount);
if (moveControlPoint)
this.getEndControlPoint().add(moveAmount);
}
else {
console.log("[CubicBezierCurve.moveCurvePoint] pointID '".concat(pointID, "' invalid."));
}
if (updateArcLengths)
this.updateArcLengths();
};
/**
* Translate the whole curve by the given {x,y} amount: moves all four points.
*
* @method translate
* @param {Vertex} amount - The amount to translate this curve by.
* @instance
* @memberof CubicBezierCurve
* @return {CubicBezierCurve} this (for chaining).
**/
CubicBezierCurve.prototype.translate = function (amount) {
this.startPoint.add(amount);
this.startControlPoint.add(amount);
this.endControlPoint.add(amount);
this.endPoint.add(amount);
return this;
};
/**
* Reverse this curve, means swapping start- and end-point and swapping
* start-control- and end-control-point.
*
* @method reverse
* @instance
* @memberof CubicBezierCurve
* @return {CubicBezierCurve} this (for chaining).
**/
CubicBezierCurve.prototype.reverse = function () {
var tmp = this.startPoint;
this.startPoint = this.endPoint;
this.endPoint = tmp;
tmp = this.startControlPoint;
this.startControlPoint = this.endControlPoint;
this.endControlPoint = tmp;
return this;
};
/**
* Get the total curve length.<br>
* <br>
* As not all Bézier curved have a closed formula to calculate their lengths, this
* implementation uses a segment buffer (with a length of 30 segments). So the
* returned length is taken from the arc segment buffer.<br>
* <br>
* Note that if the curve points were changed and the segment buffer was not
* updated this function might return wrong (old) values.
*
* @method getLength
* @instance
* @memberof CubicBezierCurve
* @return {number} >= 0
**/
CubicBezierCurve.prototype.getLength = function () {
return this.arcLength;
};
/**
* Uptate the internal arc segment buffer and their lengths.<br>
* <br>
* All class functions update the buffer automatically; if any
* curve point is changed by other reasons you should call this
* function to keep actual values in the buffer.
*
* @method updateArcLengths
* @instance
* @memberof CubicBezierCurve
* @return {void}
**/
CubicBezierCurve.prototype.updateArcLengths = function () {
var pointA = this.startPoint.clone();
var pointB = new Vertex_1.Vertex(0, 0);
var curveStep = 1.0 / this.curveIntervals;
// Clear segment cache
this.segmentCache = [];
// Push start point into buffer
this.segmentCache.push(this.startPoint);
this.segmentLengths = [];
var newLength = 0.0;
var t = 0.0;
var tmpLength;
while (t <= 1.0) {
pointB = this.getPointAt(t);
// Store point into cache
this.segmentCache.push(pointB);
// Calculate segment length
tmpLength = pointA.distance(pointB);
this.segmentLengths.push(tmpLength);
newLength += tmpLength;
pointA = pointB;
t += curveStep;
}
this.arcLength = newLength;
};
/**
* Get a 't' (relative position on curve) with the closest distance to point 'p'.
*
* The returned number is 0.0 <= t <= 1.0. Use the getPointAt(t) function to retrieve the actual curve point.
*
* This function uses a recursive approach by cutting the curve into several linear segments.
*
* @param {Vertex} p - The point to find the closest position ('t' on the curve).
* @return {number}
**/
CubicBezierCurve.prototype.getClosestT = function (p) {
// We would like to have an error that's not larger than 1.0.
var desiredEpsilon = 1.0;
var result = { t: 0, tPrev: 0.0, tNext: 1.0 };
var iteration = 0;
do {
result = this.locateIntervalByDistance(p, result.tPrev, result.tNext, this.curveIntervals);
iteration++;
// Be sure: stop after 4 iterations
} while (iteration < 4 && this.getPointAt(result.tPrev).distance(this.getPointAt(result.tNext)) > desiredEpsilon);
return result.t;
};
/**
* This helper function locates the 't' on a fixed step interval with the minimal distance
* between the curve (at 't') and the given point.
*
* Furthermore you must specify a sub curve (start 't' and end 't') you want to search on.
* Using tStart=0.0 and tEnd=1.0 will search on the full curve.
*
* @param {Vertex} p - The point to find the closest curve point for.
* @param {number} tStart - The start position (start 't' of the sub curve). Should be >= 0.0.
* @param {number} tEnd - The end position (end 't' of the sub curve). Should be <= 1.0.
* @param {number} stepCount - The number of steps to check within the interval.
*
* @return {object} - An object with t, tPrev and tNext (numbers).
**/
CubicBezierCurve.prototype.locateIntervalByDistance = function (p, tStart, tEnd, stepCount) {
var minIndex = -1;
var minDist = 0;
var t = 0.0;
var tDiff = tEnd - tStart;
for (var i = 0; i <= stepCount; i++) {
t = tStart + tDiff * (i / stepCount);
var vert = this.getPointAt(t);
var dist = vert.distance(p);
if (minIndex == -1 || dist < minDist) {
minIndex = i;
minDist = dist;
}
}
return {
t: tStart + tDiff * (minIndex / stepCount),
tPrev: tStart + tDiff * (Math.max(0, minIndex - 1) / stepCount),
tNext: tStart + tDiff * (Math.min(stepCount, minIndex + 1) / stepCount)
};
};
/**
* Get the bounds of this bezier curve.
*
* The bounds are approximated by the underlying segment buffer; the more segment there are,
* the more accurate will be the returned bounds.
*
* @return {Bounds} The bounds of this curve.
**/
CubicBezierCurve.prototype.getBounds = function () {
var min = new Vertex_1.Vertex(Number.POSITIVE_INFINITY, Number.POSITIVE_INFINITY);
var max = new Vertex_1.Vertex(Number.NEGATIVE_INFINITY, Number.NEGATIVE_INFINITY);
var v;
for (var i = 0; i < this.segmentCache.length; i++) {
v = this.segmentCache[i];
min.x = Math.min(min.x, v.x);
min.y = Math.min(min.y, v.y);
max.x = Math.max(max.x, v.x);
max.y = Math.max(max.y, v.y);
}
return new Bounds_1.Bounds(min, max);
};
/**
* Get the start point of the curve.<br>
* <br>
* This function just returns this.startPoint.
*
* @method getStartPoint
* @instance
* @memberof CubicBezierCurve
* @return {Vertex} this.startPoint
**/
CubicBezierCurve.prototype.getStartPoint = function () {
return this.startPoint;
};
/**
* Get the end point of the curve.<br>
* <br>
* This function just returns this.endPoint.
*
* @method getEndPoint
* @instance
* @memberof CubicBezierCurve
* @return {Vertex} this.endPoint
**/
CubicBezierCurve.prototype.getEndPoint = function () {
return this.endPoint;
};
/**
* Get the start control point of the curve.<br>
* <br>
* This function just returns this.startControlPoint.
*
* @method getStartControlPoint
* @instance
* @memberof CubicBezierCurve
* @return {Vertex} this.startControlPoint
**/
CubicBezierCurve.prototype.getStartControlPoint = function () {
return this.startControlPoint;
};
/**
* Get the end control point of the curve.<br>
* <br>
* This function just returns this.endControlPoint.
*
* @method getEndControlPoint
* @instance
* @memberof CubicBezierCurve
* @return {Vertex} this.endControlPoint
**/
CubicBezierCurve.prototype.getEndControlPoint = function () {
return this.endControlPoint;
};
/**
* Get one of the four curve points specified by the passt point ID.
*
* @method getEndControlPoint
* @param {number} id - One of START_POINT, START_CONTROL_POINT, END_CONTROL_POINT or END_POINT.
* @instance
* @memberof CubicBezierCurve
* @return {Vertex}
**/
CubicBezierCurve.prototype.getPointByID = function (id) {
if (id == this.START_POINT)
return this.startPoint;
if (id == this.END_POINT)
return this.endPoint;
if (id == this.START_CONTROL_POINT)
return this.startControlPoint;
if (id == this.END_CONTROL_POINT)
return this.endControlPoint;
throw new Error("Invalid point ID '".concat(id, "'."));
};
/**
* Get the curve point at a given position t, where t is in [0,1].<br>
* <br>
* @see Line.pointAt
*
* @method getPointAt
* @param {number} t - The position on the curve in [0,1] (0 means at
* start point, 1 means at end point, other values address points in bertween).
* @instance
* @memberof CubicBezierCurve
* @return {Vertex}
**/
CubicBezierCurve.prototype.getPointAt = function (t) {
// Perform some powerful math magic
var x = this.startPoint.x * Math.pow(1.0 - t, 3) +
this.startControlPoint.x * 3 * t * Math.pow(1.0 - t, 2) +
this.endControlPoint.x * 3 * Math.pow(t, 2) * (1.0 - t) +
this.endPoint.x * Math.pow(t, 3);
var y = this.startPoint.y * Math.pow(1.0 - t, 3) +
this.startControlPoint.y * 3 * t * Math.pow(1.0 - t, 2) +
this.endControlPoint.y * 3 * Math.pow(t, 2) * (1.0 - t) +
this.endPoint.y * Math.pow(t, 3);
return new Vertex_1.Vertex(x, y);
};
/**
* Get the curve point at a given position u, where u is in [0,arcLength].<br>
* <br>
* @see CubicBezierCurve.getPointAt
*
* @method getPoint
* @param {number} u - The position on the curve in [0,arcLength] (0 means at
* start point, arcLength means at end point, other values address points in bertween).
* @instance
* @memberof CubicBezierCurve
* @return {Vertex}
**/
CubicBezierCurve.prototype.getPoint = function (u) {
return this.getPointAt(u / this.arcLength);
};
/**
* Get the curve tangent vector at a given absolute curve position t in [0,1].<br>
* <br>
* Note that the returned tangent vector (end point) is not normalized and relative to (0,0).
*
* @method getTangent
* @param {number} t - The position on the curve in [0,1].
* @instance
* @memberof CubicBezierCurve
* @return {Vertex}
**/
CubicBezierCurve.prototype.getTangentAt = function (t) {
var a = this.getStartPoint();
var b = this.getStartControlPoint();
var c = this.getEndControlPoint();
var d = this.getEndPoint();
// This is the shortened one
var t2 = t * t;
// (1 - t)^2 = (1-t)*(1-t) = 1 - t - t + t^2 = 1 - 2*t + t^2
var nt2 = 1 - 2 * t + t2;
var tX = -3 * a.x * nt2 + b.x * (3 * nt2 - 6 * (t - t2)) + c.x * (6 * (t - t2) - 3 * t2) + 3 * d.x * t2;
var tY = -3 * a.y * nt2 + b.y * (3 * nt2 - 6 * (t - t2)) + c.y * (6 * (t - t2) - 3 * t2) + 3 * d.y * t2;
// Note: my implementation does NOT normalize tangent vectors!
return new Vertex_1.Vertex(tX, tY);
};
/**
* Trim off a start section of this curve. The position parameter `uValue` is the absolute position on the
* curve in `[0...arcLength]`.
* The remaining curve will be the one in the bounds `[uValue,1]` (so `[0.0,uValue]` is cut off).
*
* Note this function just converts the absolute parameter to a relative one and call `trimStartAt`.
*
* @method trimStart
* @instance
* @memberof CubicBezierCurve
* @param {number} uValue - The absolute position parameter where to cut off the head curve.
* @returns {CubicBezierCurve} `this` for chanining.
*/
CubicBezierCurve.prototype.trimStart = function (uValue) {
return this.trimStartAt(this.convertU2T(uValue));
};
/**
* Trim off a start section of this curve. The position parameter `t` is the relative position in [0..1].
* The remaining curve will be the one in the bounds `[uValue,1]` (so `[0.0,uValue]` is cut off).
*
* @method trimStartAt
* @instance
* @memberof CubicBezierCurve
* @param {number} t - The relative position parameter where to cut off the head curve.
* @returns {CubicBezierCurve} `this` for chanining.
*/
CubicBezierCurve.prototype.trimStartAt = function (t) {
var subCurbePoints = CubicBezierCurve.utils.getSubCurvePointsAt(this, t, 1.0);
this.startPoint.set(subCurbePoints[0]);
this.startControlPoint.set(subCurbePoints[2]);
this.endPoint.set(subCurbePoints[1]);
this.endControlPoint.set(subCurbePoints[3]);
this.updateArcLengths();
return this;
};
/**
* Trim off the end of this curve. The position parameter `uValue` is the absolute position on the
* curve in `[0...arcLength]`.
* The remaining curve will be the one in the bounds `[0,uValue]` (so `[1.0-uValue,1.0]` is cut off).
*
* Note this function just converts the absolute parameter to a relative one and call `trimEndAt`.
*
* @method trimEnd
* @instance
* @memberof CubicBezierCurve
* @param {number} uValue - The absolute position parameter where to cut off the tail curve.
* @returns {CubicBezierCurve} `this` for chanining.
*/
CubicBezierCurve.prototype.trimEnd = function (uValue) {
return this.trimEndAt(this.convertU2T(uValue));
};
/**
* Trim off the end of this curve. The position parameter `t` is the relative position in [0..1].
* The remaining curve will be the one in the bounds `[0,t]` (so `[1.0-t,1.0]` is cut off).
*
* @method trimEndAt
* @instance
* @memberof CubicBezierCurve
* @param {number} t - The relative position parameter where to cut off the tail curve.
* @returns {CubicBezierCurve} `this` for chanining.
*/
CubicBezierCurve.prototype.trimEndAt = function (t) {
var subCurbePoints = CubicBezierCurve.utils.getSubCurvePointsAt(this, 0.0, t);
this.startPoint.set(subCurbePoints[0]);
this.startControlPoint.set(subCurbePoints[2]);
this.endPoint.set(subCurbePoints[1]);
this.endControlPoint.set(subCurbePoints[3]);
this.updateArcLengths();
return this;
};
/**
* Get a sub curve at the given start end end positions (values on the curve's length, between 0 and curve.arcLength).
*
* tStart >= tEnd is allowed, you will get a reversed sub curve then.
*
* @method getSubCurve
* @param {number} tStart – The start position of the desired sub curve (must be in [0..arcLength]).
* @param {number} tEnd – The end position if the desired cub curve (must be in [0..arcLength]).
* @instance
* @memberof CubicBezierCurve
* @return {CubicBezierCurve} The sub curve as a new curve.
**/
CubicBezierCurve.prototype.getSubCurve = function (uStart, uEnd) {
return this.getSubCurveAt(this.convertU2T(uStart), this.convertU2T(uEnd));
};
/**
* Get a sub curve at the given start end end offsets (values between 0.0 and 1.0).
*
* tStart >= tEnd is allowed, you will get a reversed sub curve then.
*
* @method getSubCurveAt
* @param {number} tStart – The start offset of the desired sub curve (must be in [0..1]).
* @param {number} tEnd – The end offset if the desired cub curve (must be in [0..1]).
* @instance
* @memberof CubicBezierCurve
* @return {CubicBezierCurve} The sub curve as a new curve.
**/
CubicBezierCurve.prototype.getSubCurveAt = function (tStart, tEnd) {
// const startVec: Vector = new Vector(this.getPointAt(tStart), this.getTangentAt(tStart));
// const endVec: Vector = new Vector(this.getPointAt(tEnd), this.getTangentAt(tEnd).inv());
// // Tangents are relative. Make absolute.
// startVec.b.add(startVec.a);
// endVec.b.add(endVec.a);
// // This 'splits' the curve at the given point at t.
// startVec.scale(0.33333333 * (tEnd - tStart));
// endVec.scale(0.33333333 * (tEnd - tStart));
// // Draw the bezier curve
// // pb.draw.cubicBezier( startVec.a, endVec.a, startVec.b, endVec.b, '#8800ff', 2 );
// return new CubicBezierCurve(startVec.a, endVec.a, startVec.b, endVec.b);
var subCurbePoints = CubicBezierCurve.utils.getSubCurvePointsAt(this, tStart, tEnd);
return new CubicBezierCurve(subCurbePoints[0], subCurbePoints[1], subCurbePoints[2], subCurbePoints[3]);
};
/**
* Convert a relative curve position u to the absolute curve position t.
*
* @method convertU2t
* @param {number} u - The relative position on the curve in [0,arcLength].
* @instance
* @memberof CubicBezierCurve
* @return {number}
**/
CubicBezierCurve.prototype.convertU2T = function (u) {
return Math.max(0.0, Math.min(1.0, u / this.arcLength));
};
/**
* Get the curve tangent vector at a given relative position u in [0,arcLength].<br>
* <br>
* Note that the returned tangent vector (end point) is not normalized.
*
* @method getTangent
* @param {number} u - The position on the curve in [0,arcLength].
* @instance
* @memberof CubicBezierCurve
* @return {Vertex}
**/
CubicBezierCurve.prototype.getTangent = function (u) {
return this.getTangentAt(this.convertU2T(u));
};
/**
* Get the curve perpendicular at a given relative position u in [0,arcLength] as a vector.<br>
* <br>
* Note that the returned vector (end point) is not normalized.
*
* @method getPerpendicular
* @param {number} u - The relative position on the curve in [0,arcLength].
* @instance
* @memberof CubicBezierCurve
* @return {Vertex}
**/
CubicBezierCurve.prototype.getPerpendicular = function (u) {
return this.getPerpendicularAt(this.convertU2T(u));
};
/**
* Get the curve perpendicular at a given absolute position t in [0,1] as a vector.<br>
* <br>
* Note that the returned vector (end point) is not normalized.
*
* @method getPerpendicularAt
* @param {number} u - The absolute position on the curve in [0,1].
* @instance
* @memberof CubicBezierCurve
* @return {Vertex}
**/
CubicBezierCurve.prototype.getPerpendicularAt = function (t) {
var tangentVector = this.getTangentAt(t);
return new Vertex_1.Vertex(tangentVector.y, -tangentVector.x);
};
/**
* Clone this Bézier curve (deep clone).
*
* @method clone
* @instance
* @memberof CubicBezierCurve
* @return {CubicBezierCurve}
**/
CubicBezierCurve.prototype.clone = function () {
return new CubicBezierCurve(this.getStartPoint().clone(), this.getEndPoint().clone(), this.getStartControlPoint().clone(), this.getEndControlPoint().clone());
};
//---BEGIN PathSegment-------------------------
/**
* Get the tangent's end point at the start point of this segment.
*
* @method getStartTangent
* @memberof PathSegment
* @return {Vertex} The end point of the starting point's tangent.
*/
CubicBezierCurve.prototype.getStartTangent = function () {
return this.startControlPoint;
};
/**
* Get the tangent's end point at the end point of this segment.
*
* @method getEndTangent
* @memberof PathSegment
* @return {Vertex} The end point of the ending point's tangent.
*/
CubicBezierCurve.prototype.getEndTangent = function () {
return this.endControlPoint;
};
//---END PathSegment-------------------------
/**
* Check if this and the specified curve are equal.<br>
* <br>
* All four points need to be equal for this, the Vertex.equals function is used.<br>
* <br>
* Please note that this function is not type safe (comparison with any object will fail).
*
* @method clone
* @param {CubicBezierCurve} curve - The curve to compare with.
* @instance
* @memberof CubicBezierCurve
* @return {boolean}
**/
CubicBezierCurve.prototype.equals = function (curve) {
// Note: in the earlier vanilla-JS version this was callable with plain objects.
// Let's see if this restricted version works out.
if (!curve)
return false;
if (!curve.startPoint || !curve.endPoint || !curve.startControlPoint || !curve.endControlPoint)
return false;
return (this.startPoint.equals(curve.startPoint) &&
this.endPoint.equals(curve.endPoint) &&
this.startControlPoint.equals(curve.startControlPoint) &&
this.endControlPoint.equals(curve.endControlPoint));
};
/**
* 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.
*/
CubicBezierCurve.prototype.destroy = function () {
this.startPoint.destroy();
this.endPoint.destroy();
this.startControlPoint.destroy();
this.endControlPoint.destroy();
this.isDestroyed = true;
};
/**
* Quick check for class instance.
* Is there a better way?
*
* @method isInstance
* @param {any} obj - Check if the passed object/value is an instance of CubicBezierCurve.
* @instance
* @memberof CubicBezierCurve
* @return {boolean}
**/
CubicBezierCurve.isInstance = function (obj) {
// Note: check this again
/* OLD VANILLA JS IMPLEMENTATION */
/* if( typeof obj != "object" )
return false;
function hasXY(v) {
return typeof v != "undefined" && typeof v.x == "number" && typeof v.y == "number";
}
return typeof obj.startPoint == "object" && hasXY(obj.startPoint)
&& typeof obj.endPoint == "object" && hasXY(obj.endPoint)
&& typeof obj.startControlPoint == "object" && hasXY(obj.startControlPoint)
&& typeof obj.endControlPoint == "object" && hasXY(obj.endControlPoint);
*/
return obj instanceof CubicBezierCurve;
};
/**
* Convert this curve to a JSON string.
*
* @method toJSON
* @param {boolean=} [prettyFormat=false] - If set to true the function will add line breaks.
* @instance
* @memberof CubicBezierCurve
* @return {string} The JSON data.
**/
CubicBezierCurve.prototype.toJSON = function (prettyFormat) {
var jsonString = "{ " + // begin object
(prettyFormat ? "\n\t" : "") +
'"startPoint" : [' +
this.getStartPoint().x +
"," +
this.getStartPoint().y +
"], " +
(prettyFormat ? "\n\t" : "") +
'"endPoint" : [' +
this.getEndPoint().x +
"," +
this.getEndPoint().y +
"], " +
(prettyFormat ? "\n\t" : "") +
'"startControlPoint": [' +
this.getStartControlPoint().x +
"," +
this.getStartControlPoint().y +
"], " +
(prettyFormat ? "\n\t" : "") +
'"endControlPoint" : [' +
this.getEndControlPoint().x +
"," +
this.getEndControlPoint().y +
"]" +
(prettyFormat ? "\n\t" : "") +
" }"; // end object
return jsonString;
};
/**
* Parse a Bézier curve from the given JSON string.
*
* @method fromJSON
* @param {string} jsonString - The JSON data to parse.
* @memberof CubicBezierCurve
* @static
* @throws An exception if the JSON string is malformed.
* @return {CubicBezierCurve}
**/
CubicBezierCurve.fromJSON = function (jsonString) {
var obj = JSON.parse(jsonString);
return CubicBezierCurve.fromObject(obj);
};
/**
* Try to convert the passed object to a CubicBezierCurve.
*
* @method fromObject
* @param {object} obj - The object to convert.
* @memberof CubicBezierCurve
* @static
* @throws An exception if the passed object is malformed.
* @return {CubicBezierCurve}
**/
CubicBezierCurve.fromObject = function (obj) {
if (typeof obj !== "object")
throw "Can only build from object.";
if (!obj.startPoint)
throw 'Object member "startPoint" missing.';
if (!obj.endPoint)
throw 'Object member "endPoint" missing.';
if (!obj.startControlPoint)
throw 'Object member "startControlPoint" missing.';
if (!obj.endControlPoint)
throw 'Object member "endControlPoint" missing.';
return new CubicBezierCurve(new Vertex_1.Vertex(obj.startPoint[0], obj.startPoint[1]), new Vertex_1.Vertex(obj.endPoint[0], obj.endPoint[1]), new Vertex_1.Vertex(obj.startControlPoint[0], obj.startControlPoint[1]), new Vertex_1.Vertex(obj.endControlPoint[0], obj.endControlPoint[1]));
};
/**
* Convert a 4-element array of vertices to a cubic bézier curve.
*
* @method fromArray
* @param {Vertex[]} arr - [ startVertex, endVertex, startControlVertex, endControlVertex ]
* @memberof CubicBezierCurve
* @throws An exception if the passed array is malformed.
* @return {CubicBezierCurve}
**/
CubicBezierCurve.fromArray = function (arr) {
if (!Array.isArray(arr))
throw "Can only build from object.";
if (arr.length != 4)
throw "Can only build from array with four elements.";
return new CubicBezierCurve(arr[0], arr[1], arr[2], arr[3]);
};
/** @constant {number} */
CubicBezierCurve.START_POINT = 0;
/** @constant {number} */
CubicBezierCurve.START_CONTROL_POINT = 1;
/** @constant {number} */
CubicBezierCurve.END_CONTROL_POINT = 2;
/** @constant {number} */
CubicBezierCurve.END_POINT = 3;
/**
* Helper utils.
*/
CubicBezierCurve.utils = {
/**
* Get the points of a sub curve at the given start end end offsets (values between 0.0 and 1.0).
*
* tStart >= tEnd is allowed, you will get a reversed sub curve then.
*
* @method getSubCurvePointsAt
* @param {CubicBezierCurve} curve – The curve to get the sub curve points from.
* @param {number} tStart – The start offset of the desired sub curve (must be in [0..1]).
* @param {number} tEnd – The end offset if the desired cub curve (must be in [0..1]).
* @instance
* @memberof CubicBezierCurve
* @return {CubicBezierCurve} The sub curve as a new curve.
**/
getSubCurvePointsAt: function (curve, tStart, tEnd) {
var startVec = new Vector_1.Vector(curve.getPointAt(tStart), curve.getTangentAt(tStart));
var endVec = new Vector_1.Vector(curve.getPointAt(tEnd), curve.getTangentAt(tEnd).inv());
// Tangents are relative. Make absolute.
startVec.b.add(startVec.a);
endVec.b.add(endVec.a);
// This 'splits' the curve at the given point at t.
startVec.scale(0.33333333 * (tEnd - tStart));
endVec.scale(0.33333333 * (tEnd - tStart));
return [startVec.a, endVec.a, startVec.b, endVec.b];
}
};
return CubicBezierCurve;
}());
exports.CubicBezierCurve = CubicBezierCurve;
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