@jscad/modeling/src/primitives/circle.test.js

Constructive Solid Geometry (CSG) Library for JSCAD

const test = require('ava')

const { TAU } = require('../maths/constants')
const geom2 = require('../geometries/geom2')

const comparePoints = require('../../test/helpers/comparePoints')

const { circle } = require('./index')

test('circle (defaults)', (t) => {
  const geometry = circle()
  const pts = geom2.toPoints(geometry)

  t.notThrows(() => geom2.validate(geometry))
  t.deepEqual(pts.length, 32)
})

test('circle (options)', (t) => {
  // test center
  let geometry = circle({ radius: 3.5, center: [6.5, 6.5] })
  let pts = geom2.toPoints(geometry)
  let exp = [
    [10, 6.5],
    [9.932748481411306, 7.182816127056449],
    [9.733578363789503, 7.8393920132778145],
    [9.410143643058909, 8.444495815568608],
    [8.974873734152917, 8.974873734152915],
    [8.444495815568608, 9.410143643058909],
    [7.8393920132778145, 9.733578363789503],
    [7.182816127056449, 9.932748481411306],
    [6.5, 10],
    [5.817183872943551, 9.932748481411306],
    [5.1606079867221855, 9.733578363789503],
    [4.555504184431394, 9.410143643058909],
    [4.025126265847084, 8.974873734152917],
    [3.589856356941091, 8.444495815568608],
    [3.2664216362104965, 7.8393920132778145],
    [3.0672515185886935, 7.18281612705645],
    [3, 6.5],
    [3.0672515185886935, 5.81718387294355],
    [3.266421636210496, 5.160607986722186],
    [3.589856356941091, 4.555504184431394],
    [4.025126265847083, 4.025126265847084],
    [4.555504184431392, 3.5898563569410915],
    [5.160607986722184, 3.266421636210497],
    [5.817183872943549, 3.067251518588694],
    [6.5, 3],
    [7.182816127056449, 3.0672515185886935],
    [7.8393920132778145, 3.266421636210497],
    [8.444495815568606, 3.589856356941091],
    [8.974873734152915, 4.025126265847083],
    [9.410143643058909, 4.555504184431392],
    [9.733578363789503, 5.160607986722184],
    [9.932748481411306, 5.817183872943549]
  ]

  t.notThrows(() => geom2.validate(geometry))
  t.deepEqual(pts.length, 32)
  t.true(comparePoints(pts, exp))

  // test radius
  geometry = circle({ radius: 3.5, segments: 16 })
  pts = geom2.toPoints(geometry)
  exp = [
    [3.5, 0],
    [3.2335783637895035, 1.3393920132778143],
    [2.4748737341529163, 2.474873734152916],
    [1.3393920132778145, 3.2335783637895035],
    [0, 3.5],
    [-1.339392013277814, 3.2335783637895035],
    [-2.474873734152916, 2.4748737341529163],
    [-3.2335783637895035, 1.3393920132778145],
    [-3.5, 0],
    [-3.233578363789504, -1.3393920132778139],
    [-2.474873734152917, -2.474873734152916],
    [-1.339392013277816, -3.233578363789503],
    [0, -3.5],
    [1.339392013277815, -3.233578363789503],
    [2.474873734152916, -2.474873734152917],
    [3.233578363789503, -1.3393920132778163]
  ]

  t.notThrows(() => geom2.validate(geometry))
  t.deepEqual(pts.length, 16)
  t.true(comparePoints(pts, exp))

  // test startAngle
  geometry = circle({ radius: 3.5, startAngle: TAU / 4, segments: 16 })
  pts = geom2.toPoints(geometry)
  exp = [
    [0, 3.5],
    [-1.339392013277814, 3.2335783637895035],
    [-2.474873734152916, 2.4748737341529163],
    [-3.2335783637895035, 1.3393920132778145],
    [-3.5, 0],
    [-3.233578363789504, -1.3393920132778139],
    [-2.474873734152917, -2.474873734152916],
    [-1.339392013277816, -3.233578363789503],
    [0, -3.5],
    [1.339392013277815, -3.233578363789503],
    [2.474873734152916, -2.474873734152917],
    [3.233578363789503, -1.3393920132778163],
    [3.5, 0],
    [0, 0]
  ]

  t.notThrows(() => geom2.validate(geometry))
  t.deepEqual(pts.length, 14)
  t.true(comparePoints(pts, exp))

  // test endAngle
  geometry = circle({ radius: 3.5, endAngle: TAU / 4, segments: 16 })
  pts = geom2.toPoints(geometry)
  exp = [
    [3.5, 0],
    [3.2335783637895035, 1.3393920132778143],
    [2.4748737341529163, 2.474873734152916],
    [1.3393920132778145, 3.2335783637895035],
    [0, 3.5],
    [0, 0]
  ]

  t.notThrows(() => geom2.validate(geometry))
  t.deepEqual(pts.length, 6)
  t.true(comparePoints(pts, exp))

  // test full rotation with non-zero startAngle
  geometry = circle({ startAngle: 1, endAngle: 1 + TAU })
  pts = geom2.toPoints(geometry)

  t.notThrows(() => geom2.validate(geometry))
  t.deepEqual(pts.length, 32)

  // test segments
  geometry = circle({ radius: 3.5, segments: 5 })
  pts = geom2.toPoints(geometry)
  exp = [
    [3.5, 0],
    [1.081559480312316, 3.3286978070330373],
    [-2.8315594803123156, 2.0572483830236563],
    [-2.831559480312316, -2.0572483830236554],
    [1.0815594803123152, -3.3286978070330377]
  ]

  t.notThrows(() => geom2.validate(geometry))
  t.deepEqual(pts.length, 5)
  t.true(comparePoints(pts, exp))
})

test('circle (radius zero)', (t) => {
  const geometry = circle({ radius: 0 })
  const pts = geom2.toPoints(geometry)
  t.notThrows(() => geom2.validate(geometry))
  t.is(pts.length, 0)
})