Radial slit scan

let capture

let off = -1

​

function setup() {

  createCanvas(600, 600)

  capture = createCapture(VIDEO)

  capture.hide()

  background(255)

  textAlign(CENTER, CENTER)

  textSize(30)

  text('Click to start scanning', width/2, height/2)

}

​

function mouseClicked() {

  off = frameCount

  background(255)

}

​

function draw() {

  if (off > 0 && frameCount > off) {

    push()

    const r = (frameCount - off - 2) * 0.5

    const r2 = (frameCount - off) * 0.5

    clip(() => {

      beginShape()

      for (let i = 0; i <= 50; i++) {

        let a = map(i, 0, 50, 0, TWO_PI)

        vertex(width/2 + r * cos(a), height/2 + r * sin(a))

      }

      for (let i = 0; i <= 50; i++) {

        let a = map(i, 0, 50, TWO_PI, 0)

        vertex(width/2 + r2 * cos(a), height/2 + r2 * sin(a))

      }

      endShape()

    })

    translate(width/2, height/2)

    scale(-1, 1)

    imageMode(CENTER)

    image(capture, 0, 0, width, height, 0, 0, capture.width, capture.height, COVER)

    pop()

  }

}