SCRIPT-8

README.md

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

code.js

// title: Trigo-9

/* eslint-disable no-global-assign */

const min = -20
const max = 0
const delta = 0.075

initialState = {
  rd: 0,
  rdd: -delta
}

update = (state, input) => {
  state.rd += state.rdd
  if (state.rd < min || state.rd > max) {
    state.rdd *= 0
  }
  if (input.up) {
    state.rdd = delta
  }
  if (input.down) {
    state.rdd = -delta
  }
}

draw = state => {
  clear()

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

  // radius
  const r = 60
  // const rd = -20

  // compute points
  const points = range(0, 3, 0.05).map(i => {
    const angle = i * 2 * Math.PI
    const x = o.x + (r + state.rd * i) * Math.cos(angle)
    const y = o.y + (r + state.rd * i) * Math.sin(angle)
    return [x, y]
  })

  // draw points
  points.forEach((p, i, a) => {
    if (i < a.length - 1) {
      line(...p, ...a[i + 1], 4)
    }

    circFill(...p, 2, 0)
  })
}