SCRIPT-8

README.md

This is a SCRIPT-8 cassette. Click here to boot it.

code.js

// title: Trigo-7

/* eslint-disable no-global-assign */
const min = 0.05
const max = 0.25

initialState = {
  d: min,
  dd: 0.001
}

update = state => {
  state.d += state.dd
  if (state.d > max || state.d < min) {
    state.dd *= -1
  }
}

draw = state => {
  clear()

  // origin
  const o = { x: 64, y: 64 }

  // axes
  line(o.x, 0, o.x, 128, 6)
  line(0, o.y, 128, o.y, 6)

  // radius
  const r = 60

  // compute points
  const points = range(-0.5, 0.5, state.d).map(i => {
    const angle = i * 2 * Math.PI
    const x = o.x + r * Math.cos(angle)
    const y = o.y + r * Math.sin(angle)
    return [x, y]
  })

  // draw line
  polyStroke(points, 3)

  // draw points
  points.forEach(p => {
    circFill(...p, 2, 0)
  })
}