@flatten-js/core
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Javascript library for 2d geometry
259 lines (224 loc) • 8.27 kB
JavaScript
/**
* Created by Alex Bol on 3/6/2017.
*/
"use strict";
import Flatten from '../flatten';
import * as Intersection from '../algorithms/intersection';
import {convertToString} from "../utils/attributes";
import {Shape} from "./shape";
import {Matrix} from "./matrix";
import {Errors} from "../utils/errors";
/**
* Class representing a circle
* @type {Circle}
*/
export class Circle extends Shape {
/**
* Class private property
* @type {string}
*/
/**
*
* @param {Point} pc - circle center point
* @param {number} r - circle radius
*/
constructor(...args) {
super()
/**
* Circle center
* @type {Point}
*/
this.pc = new Flatten.Point();
/**
* Circle radius
* @type {number}
*/
this.r = 1;
if (args.length === 1 && args[0] instanceof Object && args[0].name === "circle") {
let {pc, r} = args[0];
this.pc = new Flatten.Point(pc);
this.r = r;
} else {
let [pc, r] = [...args];
if (pc && pc instanceof Flatten.Point) this.pc = pc.clone();
if (r !== undefined) this.r = r;
}
// throw Errors.ILLEGAL_PARAMETERS; unreachable code
}
/**
* Return new cloned instance of circle
* @returns {Circle}
*/
clone() {
return new Flatten.Circle(this.pc.clone(), this.r);
}
/**
* Circle center
* @returns {Point}
*/
get center() {
return this.pc;
}
/**
* Circle bounding box
* @returns {Box}
*/
get box() {
return new Flatten.Box(
this.pc.x - this.r,
this.pc.y - this.r,
this.pc.x + this.r,
this.pc.y + this.r
);
}
/**
* Return true if circle contains shape: no point of shape lies outside of the circle
* @param {Shape} shape - test shape
* @returns {boolean}
*/
contains(shape) {
if (shape instanceof Flatten.Point) {
return Flatten.Utils.LE(shape.distanceTo(this.center)[0], this.r);
}
if (shape instanceof Flatten.Segment) {
return Flatten.Utils.LE(shape.start.distanceTo(this.center)[0], this.r) &&
Flatten.Utils.LE(shape.end.distanceTo(this.center)[0], this.r);
}
if (shape instanceof Flatten.Arc) {
return this.intersect(shape).length === 0 &&
Flatten.Utils.LE(shape.start.distanceTo(this.center)[0], this.r) &&
Flatten.Utils.LE(shape.end.distanceTo(this.center)[0], this.r);
}
if (shape instanceof Flatten.Circle) {
return this.intersect(shape).length === 0 &&
Flatten.Utils.LE(shape.r, this.r) &&
Flatten.Utils.LE(shape.center.distanceTo(this.center)[0], this.r);
}
/* TODO: box, polygon */
}
/**
* Transform circle to closed arc
* @param {boolean} counterclockwise
* @returns {Arc}
*/
toArc(counterclockwise = true) {
return new Flatten.Arc(this.center, this.r, Math.PI, -Math.PI, counterclockwise);
}
/**
* Method scale is supported only for uniform scaling of the circle with (0,0) center
* @param {number} sx
* @param {number} sy
* @returns {Circle}
*/
scale(sx, sy) {
if (sx !== sy)
throw Errors.OPERATION_IS_NOT_SUPPORTED
if (!(this.pc.x === 0.0 && this.pc.y === 0.0))
throw Errors.OPERATION_IS_NOT_SUPPORTED
return new Flatten.Circle(this.pc, this.r*sx)
}
/**
* Return new circle transformed using affine transformation matrix
* @param {Matrix} matrix - affine transformation matrix
* @returns {Circle}
*/
transform(matrix = new Flatten.Matrix()) {
return new Flatten.Circle(this.pc.transform(matrix), this.r)
}
/**
* Returns array of intersection points between circle and other shape
* @param {Shape} shape Shape of the one of supported types
* @returns {Point[]}
*/
intersect(shape) {
if (shape instanceof Flatten.Point) {
return this.contains(shape) ? [shape] : [];
}
if (shape instanceof Flatten.Line) {
return Intersection.intersectLine2Circle(shape, this);
}
if (shape instanceof Flatten.Ray) {
return Intersection.intersectRay2Circle(shape, this);
}
if (shape instanceof Flatten.Segment) {
return Intersection.intersectSegment2Circle(shape, this);
}
if (shape instanceof Flatten.Circle) {
return Intersection.intersectCircle2Circle(shape, this);
}
if (shape instanceof Flatten.Box) {
return Intersection.intersectCircle2Box(this, shape);
}
if (shape instanceof Flatten.Arc) {
return Intersection.intersectArc2Circle(shape, this);
}
if (shape instanceof Flatten.Polygon) {
return Intersection.intersectCircle2Polygon(this, shape);
}
if (shape instanceof Flatten.Multiline) {
return Intersection.intersectShape2Multiline(this, shape);
}
}
/**
* Calculate distance and shortest segment from circle to shape and return array [distance, shortest segment]
* @param {Shape} shape Shape of the one of supported types Point, Line, Circle, Segment, Arc, Polygon or Planar Set
* @returns {number} distance from circle to shape
* @returns {Segment} shortest segment between circle and shape (started at circle, ended at shape)
*/
distanceTo(shape) {
if (shape instanceof Flatten.Point) {
let [distance, shortest_segment] = Flatten.Distance.point2circle(shape, this);
shortest_segment = shortest_segment.reverse();
return [distance, shortest_segment];
}
if (shape instanceof Flatten.Circle) {
let [distance, shortest_segment] = Flatten.Distance.circle2circle(this, shape);
return [distance, shortest_segment];
}
if (shape instanceof Flatten.Line) {
let [distance, shortest_segment] = Flatten.Distance.circle2line(this, shape);
return [distance, shortest_segment];
}
if (shape instanceof Flatten.Segment) {
let [distance, shortest_segment] = Flatten.Distance.segment2circle(shape, this);
shortest_segment = shortest_segment.reverse();
return [distance, shortest_segment];
}
if (shape instanceof Flatten.Arc) {
let [distance, shortest_segment] = Flatten.Distance.arc2circle(shape, this);
shortest_segment = shortest_segment.reverse();
return [distance, shortest_segment];
}
if (shape instanceof Flatten.Polygon) {
let [distance, shortest_segment] = Flatten.Distance.shape2polygon(this, shape);
return [distance, shortest_segment];
}
if (shape instanceof Flatten.PlanarSet) {
let [dist, shortest_segment] = Flatten.Distance.shape2planarSet(this, shape);
return [dist, shortest_segment];
}
if (shape instanceof Flatten.Multiline) {
let [dist, shortest_segment] = Flatten.Distance.shape2multiline(this, shape);
return [dist, shortest_segment];
}
}
get name() {
return "circle"
}
/**
* Return string to draw circle in svg
* @param {Object} attrs - an object with attributes of svg circle element
* @returns {string}
*/
svg(attrs = {}) {
return `\n<circle cx="${this.pc.x}" cy="${this.pc.y}" r="${this.r}"
${convertToString({fill: "none", ...attrs})} />`;
}
}
Flatten.Circle = Circle;
/**
* Shortcut to create new circle
* @param args
*/
export const circle = (...args) => new Flatten.Circle(...args);
Flatten.circle = circle;