openlayers/test/node/ol/geom/flat/orient.test.js

import expect from '../../../expect.js';
import {
  linearRingIsClockwise,
  linearRingsAreOriented,
  linearRingssAreOriented,
  orientLinearRings,
  orientLinearRingsArray,
} from '../../../../../src/ol/geom/flat/orient.js';

describe('ol/geom/flat/orient.js', function () {
  describe('linearRingIsClockwise', function () {
    it('identifies clockwise rings', function () {
      const flatCoordinates = [0, 1, 1, 4, 4, 3, 3, 0];
      const isClockwise = linearRingIsClockwise(
        flatCoordinates,
        0,
        flatCoordinates.length,
        2
      );
      expect(isClockwise).to.be(true);
    });

    it('identifies anti-clockwise rings', function () {
      const flatCoordinates = [2, 2, 3, 2, 3, 3, 2, 3];
      const isClockwise = linearRingIsClockwise(
        flatCoordinates,
        0,
        flatCoordinates.length,
        2
      );
      expect(isClockwise).to.be(false);
    });

    it('identifies clockwise with duplicated coordinates', function () {
      const flatCoordinates = [0, 1, 0, 1, 1, 4, 1, 4, 4, 3, 4, 3, 3, 0, 3, 0];
      const isClockwise = linearRingIsClockwise(
        flatCoordinates,
        0,
        flatCoordinates.length,
        2
      );
      expect(isClockwise).to.be(true);
    });

    it('identifies anti-clockwise with duplicated coordinates', function () {
      const flatCoordinates = [2, 2, 2, 2, 3, 2, 3, 2, 3, 3, 3, 3, 2, 3, 2, 3];
      const isClockwise = linearRingIsClockwise(
        flatCoordinates,
        0,
        flatCoordinates.length,
        2
      );
      expect(isClockwise).to.be(false);
    });

    it('identifies clockwise when last coordinate equals first', function () {
      const flatCoordinates = [0, 1, 1, 4, 4, 3, 3, 0, 0, 1];
      const isClockwise = linearRingIsClockwise(
        flatCoordinates,
        0,
        flatCoordinates.length,
        2
      );
      expect(isClockwise).to.be(true);
    });

    it('identifies anti-clockwise when last coordinate equals first', function () {
      const flatCoordinates = [2, 2, 3, 2, 3, 3, 2, 3, 2, 2];
      const isClockwise = linearRingIsClockwise(
        flatCoordinates,
        0,
        flatCoordinates.length,
        2
      );
      expect(isClockwise).to.be(false);
    });

    it('returns undefined when ring has too few vertices', function () {
      const flatCoordinates = [2, 2, 3, 2];
      const isClockwise = linearRingIsClockwise(
        flatCoordinates,
        0,
        flatCoordinates.length,
        2
      );
      expect(isClockwise).to.be(undefined);
    });
  });

  describe('linearRingsAreOriented', function () {
    const oriented = linearRingsAreOriented;

    const rightCoords = [
      -180, -90, 180, -90, 180, 90, -180, 90, -180, -90, -100, -45, -100, 45,
      100, 45, 100, -45, -100, -45,
    ];

    const leftCoords = [
      -180, -90, -180, 90, 180, 90, 180, -90, -180, -90, -100, -45, 100, -45,
      100, 45, -100, 45, -100, -45,
    ];

    const ends = [10, 20];

    it('checks for left-hand orientation by default', function () {
      expect(oriented(rightCoords, 0, ends, 2)).to.be(false);
      expect(oriented(leftCoords, 0, ends, 2)).to.be(true);
    });

    it('can check for right-hand orientation', function () {
      expect(oriented(rightCoords, 0, ends, 2, true)).to.be(true);
      expect(oriented(leftCoords, 0, ends, 2, true)).to.be(false);
    });
  });

  describe('linearRingssAreOriented', function () {
    const oriented = linearRingssAreOriented;

    const rightCoords = [
      -180, -90, 180, -90, 180, 90, -180, 90, -180, -90, -100, -45, -100, 45,
      100, 45, 100, -45, -100, -45, -180, -90, 180, -90, 180, 90, -180, 90,
      -180, -90, -100, -45, -100, 45, 100, 45, 100, -45, -100, -45,
    ];

    const leftCoords = [
      -180, -90, -180, 90, 180, 90, 180, -90, -180, -90, -100, -45, 100, -45,
      100, 45, -100, 45, -100, -45, -180, -90, -180, 90, 180, 90, 180, -90,
      -180, -90, -100, -45, 100, -45, 100, 45, -100, 45, -100, -45,
    ];

    const ends = [
      [10, 20],
      [30, 40],
    ];

    it('checks for left-hand orientation by default', function () {
      expect(oriented(rightCoords, 0, ends, 2)).to.be(false);
      expect(oriented(leftCoords, 0, ends, 2)).to.be(true);
    });

    it('can check for right-hand orientation', function () {
      expect(oriented(rightCoords, 0, ends, 2, true)).to.be(true);
      expect(oriented(leftCoords, 0, ends, 2, true)).to.be(false);
    });
  });

  describe('orientLinearRings', function () {
    const orient = orientLinearRings;

    const rightCoords = [
      -180, -90, 180, -90, 180, 90, -180, 90, -180, -90, -100, -45, -100, 45,
      100, 45, 100, -45, -100, -45,
    ];

    const leftCoords = [
      -180, -90, -180, 90, 180, 90, 180, -90, -180, -90, -100, -45, 100, -45,
      100, 45, -100, 45, -100, -45,
    ];

    const ends = [10, 20];

    it('orients using the left-hand rule by default', function () {
      const rightClone = rightCoords.slice();
      orient(rightClone, 0, ends, 2);
      expect(rightClone).to.eql(leftCoords);

      const leftClone = leftCoords.slice();
      orient(leftClone, 0, ends, 2);
      expect(leftClone).to.eql(leftCoords);
    });

    it('can orient using the right-hand rule', function () {
      const rightClone = rightCoords.slice();
      orient(rightClone, 0, ends, 2, true);
      expect(rightClone).to.eql(rightCoords);

      const leftClone = leftCoords.slice();
      orient(leftClone, 0, ends, 2, true);
      expect(leftClone).to.eql(rightCoords);
    });
  });

  describe('orientLinearRingsArray', function () {
    const orient = orientLinearRingsArray;

    const rightCoords = [
      -180, -90, 180, -90, 180, 90, -180, 90, -180, -90, -100, -45, -100, 45,
      100, 45, 100, -45, -100, -45, -180, -90, 180, -90, 180, 90, -180, 90,
      -180, -90, -100, -45, -100, 45, 100, 45, 100, -45, -100, -45,
    ];

    const leftCoords = [
      -180, -90, -180, 90, 180, 90, 180, -90, -180, -90, -100, -45, 100, -45,
      100, 45, -100, 45, -100, -45, -180, -90, -180, 90, 180, 90, 180, -90,
      -180, -90, -100, -45, 100, -45, 100, 45, -100, 45, -100, -45,
    ];

    const ends = [
      [10, 20],
      [30, 40],
    ];

    it('orients using the left-hand rule by default', function () {
      const rightClone = rightCoords.slice();
      orient(rightClone, 0, ends, 2);
      expect(rightClone).to.eql(leftCoords);

      const leftClone = leftCoords.slice();
      orient(leftClone, 0, ends, 2);
      expect(leftClone).to.eql(leftCoords);
    });

    it('can orient using the right-hand rule', function () {
      const rightClone = rightCoords.slice();
      orient(rightClone, 0, ends, 2, true);
      expect(rightClone).to.eql(rightCoords);

      const leftClone = leftCoords.slice();
      orient(leftClone, 0, ends, 2, true);
      expect(leftClone).to.eql(rightCoords);
    });
  });
});