igeom/src/app/components/circumference-component/models/circumference-model.js

import { ELEMENTS_CLASS } from "../../../core/enums/elements-class-enum";
import { GeometricObject } from "../../../core/models/objects/geometric-object";
import { IntersectionModel } from "../../intersection-component/models/intersection-model";
export class CircumferenceModel extends GeometricObject {
  constructor(center, radius, id) {
    super(id);
    this.center = center;
    this.radius = radius;
    this._coordinates = [];
    this._coordinates[0] = this.center.posX;
    this._coordinates[1] = this.center.posY;
    this._coordinates[2] = this.radius.posX;
    this._coordinates[3] = this.radius.posY;
    super.setClass(ELEMENTS_CLASS.CIRCUMFERENCE);
  }
  getRadius() {
    this._coordinates[0] = this.center.posX;
    this._coordinates[1] = this.center.posY;
    this._coordinates[2] = this.radius.posX;
    this._coordinates[3] = this.radius.posY;
    const legA = this._coordinates[2] - this._coordinates[0];
    const legB = this._coordinates[3] - this._coordinates[1];
    const radius = Math.sqrt(Math.pow(legA, 2) + Math.pow(legB, 2));
    return radius;
  }

  getStraight() {
    const dx = this.radius.posX - this.center.posX;
    const dy = this.radius.posY - this.center.posY;
    const c = Math.sqrt(dy * dy + dx * dx);
    return [dx, dy, c];
  }

  getDirection() {
    const aX = this.center.posX;
    const aY = this.center.posY;
    const bX = this.radius.posX;
    const bY = this.radius.posY;
    const a = bX - aX;
    const b = bY - aY;
    return [a, b];
  }
  getIntersection(geometricObject) {
    switch (geometricObject.elementClass) {
      case ELEMENTS_CLASS.LINE_SEGMENT:
        return this.getIntersectionByLine(geometricObject);
      case ELEMENTS_CLASS.CIRCUMFERENCE:
        return this.getIntersectionsByCircumference(geometricObject);
      default:
        break;
    }
  }
  distance(center) {
    const dx = center.posX - this.center.posX;
    const dy = center.posY - this.center.posY;
    const dist = Math.sqrt(dy * dy + dx * dx);
    return dist;
  }
  getIntersectionsByCircumference(circumference) {
    // if (this.cente().igual(cd.C()))
    // return null; // duas circ. com mesmo raio => devolva "null" (ambiguidade!)
    const r1 = this.getRadius(); // raio circ. atual
    const r2 = circumference.getRadius(); // raio circ. "cd"
    const d = this.distance(circumference); // distancia entre os raios das circ.
    if (r1 + r2 < d || Math.abs(r1 - r2) > d) return null;
    const A = this.center; // pega o centro da circunferencia atual
    const B = circumference.center; // pega o centro da circunferencia "cd"
    const x = B.posX - A.posX;
    const y = B.posY - A.posY;
    let cos = x / Math.sqrt(x * x + y * y); //(B.posX-A.posX)/Math.sqrt(x*x + y*y); // cos a = <z,w>/(|z||w|)
    let sen = Math.sqrt(1 - cos * cos);
    if (A.posY > B.posY) sen = -sen;
    let u1 = B.posX - A.posX;
    let v1 = B.posY - A.posY;
    let u = u1 * cos + v1 * sen;
    let v = -u1 * sen + v1 * cos;
    const rA = this.getRadius();
    const rB = circumference.getRadius();
    u = (u * u - rB * rB + rA * rA) / (2 * u);
    v = Math.sqrt(rA * rA - u * u);
    v1 = v;
    let v2 = -v;
    let x1 = u * cos - v1 * sen;
    let y1 = u * sen + v1 * cos;
    let x2 = u * cos - v2 * sen;
    let y2 = u * sen + v2 * cos;
    x1 = A.posX + x1;
    y1 = A.posY + y1;
    x2 = A.posX + x2;
    y2 = A.posY + y2;
    return [
      new IntersectionModel(x1, y1, undefined, this, circumference, true, 0),
      new IntersectionModel(x2, y2, undefined, this, circumference, true, 1)
    ];
  }

  getIntersectionByLine(lineSegment) {
    const r = this.getStraight();
    const s = lineSegment.getStraight();
    const a1 = r[0];
    const b1 = r[1];
    const c1 = r[2];
    const a2 = s[0];
    const b2 = s[1];
    const c2 = s[2];
    const determinant = a1 * b2 - a2 * b1;
    if (determinant == 0) {
      return [
        new IntersectionModel(
          Number.MAX_SAFE_INTEGER,
          Number.MAX_SAFE_INTEGER,
          undefined,
          this,
          lineSegment
        )
      ];
    } else {
      const x = (b2 * c1 - b1 * c2) / determinant;
      const y = (a1 * c2 - a2 * c1) / determinant;
      return [new IntersectionModel(x, y, undefined, this, lineSegment)];
    }
  }

  insideSegment(intersecX, intersecY) {
    const valuesR = this.getDirection();
    const dirX = valuesR[0];
    const dirY = valuesR[1];
    const cInterA = dirX * intersecX + dirY * intersecY;

    // comparaca cv do ponto A > cv da intersec =>  vazio
    const cRA = dirX * this.center.posX + dirY * this.center.posY;

    if (cInterA < cRA) {
      return false;
    }

    // comparaca cv do ponto B < cv da intersec =>  vazio
    const cRB = dirX * this.radius.posX + dirY * this.radius.posY;

    if (cInterA > cRB) {
      this.posX = Number.MAX_SAFE_INTEGER;
      this.posY = Number.MAX_SAFE_INTEGER;
      return false;
    }

    return true;
  }
}