@flatten-js/core
Version:
Javascript library for 2d geometry
230 lines (196 loc) • 7.56 kB
JavaScript
/**
* Created by Alex Bol on 3/6/2017.
*/
"use strict";
import Flatten from '../flatten';
import * as Intersection from '../algorithms/intersection';
/**
* Class representing a circle
* @type {Circle}
*/
export class Circle {
/**
*
* @param {Point} pc - circle center point
* @param {number} r - circle radius
*/
constructor(...args) {
/**
* 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;
return;
} else {
let [pc, r] = [...args];
if (pc && pc instanceof Flatten.Point) this.pc = pc.clone();
if (r !== undefined) this.r = r;
return;
}
throw Flatten.Errors.ILLEGAL_PARAMETERS;
}
/**
* 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);
}
/**
* 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.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);
}
}
/**
* 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];
}
}
/**
* This method returns an object that defines how data will be
* serialized when called JSON.stringify() method
* @returns {Object}
*/
toJSON() {
return Object.assign({}, this, {name: "circle"});
}
/**
* Return string to draw circle in svg
* @param {Object} attrs - an object with attributes of svg circle element,
* like "stroke", "strokeWidth", "fill" <br/>
* Defaults are stroke:"black", strokeWidth:"1", fill:"none"
* @returns {string}
*/
svg(attrs = {}) {
let {stroke, strokeWidth, fill, fillOpacity, id, className} = attrs;
// let rest_str = Object.keys(rest).reduce( (acc, key) => acc += ` ${key}="${rest[key]}"`, "");
let id_str = (id && id.length > 0) ? `id="${id}"` : "";
let class_str = (className && className.length > 0) ? `class="${className}"` : "";
return `\n<circle cx="${this.pc.x}" cy="${this.pc.y}" r="${this.r}" stroke="${stroke || "black"}" stroke-width="${strokeWidth || 1}" fill="${fill || "none"}" fill-opacity="${fillOpacity || 1.0}" ${id_str} ${class_str} />`;
}
};
Flatten.Circle = Circle;
/**
* Shortcut to create new circle
* @param args
*/
export const circle = (...args) => new Flatten.Circle(...args);
Flatten.circle = circle;