modeling/src/primitives/torus.js

  1. const { TAU } = require('../maths/constants')
  3. const extrudeRotate = require('../operations/extrusions/extrudeRotate')
  4. const { rotate } = require('../operations/transforms/rotate')
  5. const { translate } = require('../operations/transforms/translate')
  7. const circle = require('./circle')
  9. const { isGT, isGTE } = require('./commonChecks')
  11. /**
  12.  * Construct a torus by revolving a small circle (inner) about the circumference of a large (outer) circle.
  13.  * @param {Object} [options] - options for construction
  14.  * @param {Number} [options.innerRadius=1] - radius of small (inner) circle
  15.  * @param {Number} [options.outerRadius=4] - radius of large (outer) circle
  16.  * @param {Integer} [options.innerSegments=32] - number of segments to create per rotation
  17.  * @param {Integer} [options.outerSegments=32] - number of segments to create per rotation
  18.  * @param {Integer} [options.innerRotation=0] - rotation of small (inner) circle in radians
  19.  * @param {Number} [options.outerRotation=TAU] - rotation (outer) of the torus (RADIANS)
  20.  * @param {Number} [options.startAngle=0] - start angle of the torus (RADIANS)
  21.  * @returns {geom3} new 3D geometry
  22.  * @alias module:modeling/primitives.torus
  23.  *
  24.  * @example
  25.  * let myshape = torus({ innerRadius: 10, outerRadius: 100 })
  26.  */
  27. const torus = (options) => {
  28.   const defaults = {
  29.     innerRadius: 1,
  30.     innerSegments: 32,
  31.     outerRadius: 4,
  32.     outerSegments: 32,
  33.     innerRotation: 0,
  34.     startAngle: 0,
  35.     outerRotation: TAU
  36.   }
  37.   const { innerRadius, innerSegments, outerRadius, outerSegments, innerRotation, startAngle, outerRotation } = Object.assign({}, defaults, options)
  39.   if (!isGT(innerRadius, 0)) throw new Error('innerRadius must be greater than zero')
  40.   if (!isGTE(innerSegments, 3)) throw new Error('innerSegments must be three or more')
  41.   if (!isGT(outerRadius, 0)) throw new Error('outerRadius must be greater than zero')
  42.   if (!isGTE(outerSegments, 3)) throw new Error('outerSegments must be three or more')
  43.   if (!isGTE(startAngle, 0)) throw new Error('startAngle must be positive')
  44.   if (!isGT(outerRotation, 0)) throw new Error('outerRotation must be greater than zero')
  46.   if (innerRadius >= outerRadius) throw new Error('inner circle is too large to rotate about the outer circle')
  48.   let innerCircle = circle({ radius: innerRadius, segments: innerSegments })
  50.   if (innerRotation !== 0) {
  51.     innerCircle = rotate([0, 0, innerRotation], innerCircle)
  52.   }
  54.   innerCircle = translate([outerRadius, 0], innerCircle)
  56.   const extrudeOptions = {
  57.     startAngle: startAngle,
  58.     angle: outerRotation,
  59.     segments: outerSegments
  60.   }
  61.   return extrudeRotate(extrudeOptions, innerCircle)
  62. }
  64. module.exports = torus