@jscad/modeling/src/curves/bezier/arcLengthToT.test.js

Constructive Solid Geometry (CSG) Library for JSCAD

const test = require('ava')

const { bezier } = require('../index')
const length = require('./length')
const arcLengthToT = require('./arcLengthToT')

const { nearlyEqual } = require('../../../test/helpers/index')

test('calculate arcLengthToT for an 1D linear bezier with numeric control points', (t) => {
  const bezierCurve = bezier.create([0, 10])
  const len = length(100, bezierCurve)
  nearlyEqual(t, arcLengthToT({ distance: 0 }, bezierCurve), 0, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len / 2 }, bezierCurve), 0.5, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len }, bezierCurve), 1, 0.0001)
  t.true(true)
})

test('calculate arcLengthToT for an 1D linear bezier with array control points', (t) => {
  const bezierCurve = bezier.create([[0], [10]])
  const len = length(100, bezierCurve)
  nearlyEqual(t, arcLengthToT({ distance: 0 }, bezierCurve), 0, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len / 2 }, bezierCurve), 0.5, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len }, bezierCurve), 1, 0.0001)
  t.true(true)
})

test('calculate arcLengthToT for a 2D linear bezier', (t) => {
  const bezierCurve = bezier.create([[0, 0], [10, 10]])
  const len = length(100, bezierCurve)
  nearlyEqual(t, arcLengthToT({ distance: 0 }, bezierCurve), 0, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len / 2 }, bezierCurve), 0.5, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len }, bezierCurve), 1, 0.0001)
  t.true(true)
})

test('calculate arcLengthToT for a 2D quadratic (3 control points) bezier', (t) => {
  const bezierCurve = bezier.create([[0, 0], [0, 10], [10, 10]])
  const len = length(100, bezierCurve)
  nearlyEqual(t, arcLengthToT({ distance: 0 }, bezierCurve), 0, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len / 2 }, bezierCurve), 0.50001, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len }, bezierCurve), 1, 0.0001)
  t.true(true)
})

test('calculate arcLengthToT for a 2D cubic (4 control points) bezier', (t) => {
  const bezierCurve = bezier.create([[0, 0], [0, 10], [10, 10], [10, 0]])
  const len = length(100, bezierCurve)
  nearlyEqual(t, arcLengthToT({ distance: 0 }, bezierCurve), 0, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len / 2 }, bezierCurve), 0.49999, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len }, bezierCurve), 1, 0.0001)
  t.true(true)
})

test('calculate arcLengthToT for a 3D linear bezier', (t) => {
  const bezierCurve = bezier.create([[0, 0, 0], [10, 10, 10]])
  const len = length(100, bezierCurve)
  nearlyEqual(t, arcLengthToT({ distance: 0 }, bezierCurve), 0, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len / 2 }, bezierCurve), 0.49999, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len }, bezierCurve), 1, 0.0001)
  t.true(true)
})

test('calculate arcLengthToT for a 3D quadratic (3 control points) bezier', (t) => {
  const bezierCurve = bezier.create([[0, 0, 0], [5, 5, 5], [0, 0, 10]])
  const len = length(100, bezierCurve)
  nearlyEqual(t, arcLengthToT({ distance: 0 }, bezierCurve), 0, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len / 2 }, bezierCurve), 0.49999, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len }, bezierCurve), 1, 0.0001)
  t.true(true)
})

test('calculate arcLengthToT for a 3D cubic (4 control points) bezier', (t) => {
  const bezierCurve = bezier.create([[0, 0, 0], [5, 5, 5], [0, 0, 10], [-5, -5, 5]])
  const len = length(100, bezierCurve)
  nearlyEqual(t, arcLengthToT({ distance: 0 }, bezierCurve), 0, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len / 2 }, bezierCurve), 0.5621, 0.0001)
  nearlyEqual(t, arcLengthToT({ distance: len }, bezierCurve), 1, 0.0001)
  t.true(true)
})