Trying to animate vector graphics using doodle library. / published by https://github.com/dacr/code-examples-manager #b6b3e414-1fea-47a1-8948-98fadb10b257/819b27a6167e31e3e547d0ef28a44a309640f187

vectorgraphics-doodle-animate-example.sc

// summary : Trying to animate vector graphics using doodle library.
// keywords : scala, vector-graphics, doodle, examples, @testable
// publish : gist
// authors : Noel Welsh, David Crosson
// license : Apache License Version 2.0 (https://www.apache.org/licenses/LICENSE-2.0.txt)
// id : b6b3e414-1fea-47a1-8948-98fadb10b257
// created-on : 2019-06-25T21:04:29Z
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala "3.4.2"
//> using dep "org.creativescala::doodle:0.10.1"
// ---------------------

// Example coming from doodle examples code (PulsingCircle.scala), author is Noel Welsh
// https://github.com/creativescala/doodle/blob/master/java2d/src/main/scala/doodle/java2d/examples/PulsingCircle.scala

object TryIt {

  import cats.instances.all._
  import doodle.core._
  import doodle.effect.Writer.Gif
  import doodle.syntax.all._
  import doodle.java2d.effect._
  import doodle.interact.syntax._
  import fs2.Stream
  import cats.effect.IO
  import doodle.java2d._
  import cats.effect.unsafe.implicits.global

  val frame = Frame.size(600, 600).background(Color.darkMagenta)

  val strokeWidth      = 9.0
  val gapWidth         = 6.0
  val minimumDiameter  = gapWidth + strokeWidth
  val maxNumberOfDisks = 15

  def disk(count: Int): Picture[Unit] =
    count match {
      case 0 =>
        circle[Algebra, Drawing](minimumDiameter.toDouble).noFill
          .strokeWidth(strokeWidth)
      case n =>
        circle[Algebra, Drawing](
          (n * 2 * (strokeWidth + gapWidth) + minimumDiameter)
        ).noFill
          .strokeWidth(strokeWidth)
    }

  def background(count: Int): Picture[Unit] = {
    def iter(count: Int): Picture[Unit] =
      count match {
        case 0 =>
          disk(count)
        case n =>
          disk(count).on(iter(n - 1))
      }

    iter(count).strokeWidth(strokeWidth.toDouble).strokeColor(Color.darkGray)
  }

  def pulse(count: Int): Picture[Unit] =
    count match {
      case 0 => disk(0).strokeColor(Color.crimson)
      case 1 =>
        disk(1)
          .strokeColor(Color.crimson)
          .on(disk(0).strokeColor(Color.crimson.spin(30.degrees)))
      case n =>
        disk(n)
          .strokeColor(Color.crimson)
          .on(
            disk(n - 1)
              .strokeColor(Color.crimson.spin(30.degrees))
          )
          .on(
            disk(n - 2)
              .strokeColor(Color.crimson.spin(60.degrees))
          )
    }

  val animation: Stream[IO, Picture[Unit]] =
    Stream(1).repeat
      .scan((1, 0)) { (state, _) =>
        val (inc, count) = state
        if (count >= maxNumberOfDisks) (-1, maxNumberOfDisks - 1)
        else if (count <= 0) (1, 1)
        else (inc, count + inc)
      }
      .map { case (_, c) => pulse(c).on(background(maxNumberOfDisks)) }

  def go() =
    animation.animate(frame)

  def write() =
    animation.take(maxNumberOfDisks * 2).write[Gif]("bouncy-circles.gif", frame)
}

//TryIt.go()
//scala.io.StdIn.readLine("Enter to exit...") // required when run as a script
TryIt.write()
//scala.io.StdIn.readLine("Enter to exit...") // required when run as a script
//System.exit(0)