MultipartTut.scala

import scala.runtime.ScalaRunTime.stringOf
import scala.collection.JavaConverters._

// stuff for verifying results, skip to case defs (comment -- 1 --)
def doVerify[A](name: String, origRes: A, myRes: A) {
  val equals = origRes match {
    case a: Array[_] => a.sameElements(myRes.asInstanceOf[Array[_]])
    case _ => origRes.equals(myRes)
  }
  if (equals) println(s"Case '$name' fine: ${stringOf(myRes)}")
  else println(s"Case '$name' wrong:\n${stringOf(origRes)}\nvs.\n${stringOf(myRes)}")
}

def verify[A, R](name: String, orig: (A) => R, mine: (A) => R, testVal: A) {
  doVerify(name, orig(testVal), mine(testVal))
}

def verify[R](name: String, orig: () => R, mine: () => R) {
  doVerify(name, orig(), mine())
}

// -- 1 --
def case1orig(oBounds: Seq[Int]) = {
  var boxes = Seq(oBounds(6))
  for (s <- 0 until 6) boxes :+= oBounds(s)
  boxes
}

def case1mine(oBounds: Seq[Int]) = oBounds.last +: oBounds.init

verify("1", case1orig, case1mine, 0 to 6)
// -------

// -- 2 --
def case2orig() = {
  val w = "someExpression"
  w
}

def case2mine() = "someExpression"

verify("2", case2orig, case2mine)

// same with returning in generateBoxes, generateCollisionBoxes 
// -------

// -- 3 --
// Does getOcclusionBoxes even compile? There is no return value in "if" branch.
/*
    override def getOcclusionBoxes = {
        import mlb.technica.experience.PipeBoxes._
        if (true)
        else Seq(oBounds(6)).asJava
    }
*/

// Possibly what you meant:
def case3orig(oBounds: Seq[Int]) = {
  if (true) Seq().asJava
  else Seq(oBounds(6)).asJava
}

def case3mine(oBounds: Seq[Int]) = Seq().asJava

verify("3", case3orig, case3mine, 0 to 6)
// -------

// -- 4 --
// Some implementation of used classes in snippet
class Cuboid6(var a: Double, var b: Double, var c: Double, var d: Double, var e: Double, var f: Double) {
  def apply(r: Rotation): Cuboid6 = {
    a -= r.x
    b -= r.y
    c -= r.z
    d -= 7 * r.x
    e -= 9 * r.y
    f -= 13 * r.x
    this
  }

  override def equals(that: Any) =
    that match {
      case t: Cuboid6 => t.a == a && t.b == b && t.c == c && t.d == d && t.e == e && t.f == f
      case _ => false
    }

  override def toString() = s"Cuboid6($a, $b, $c, $d, $e, $f)"
}

class Rotation(val x: Double, val y: Double, val z: Double) {
  def at(v: Vector3): Rotation = new Rotation(x + v.x, y + 2 * v.y, z + 3 * v.z)
}

object Rotation {
  val sideRotations = (0 to 6).map(v => new Rotation(1.0 / (v + .1), 5.0 / (v + 2), 5 * (v - 3)))
}

class Vector3(val x: Double, val y: Double, val z: Double)

object Vector3 {
  lazy val center = new Vector3(11, 23, 27)
}

// PipeBoxes.oBounds
def case4orig() = {
  val boxes = new Array[Cuboid6](7)
  val w = 2 / 8D
  boxes(6) = new Cuboid6(0.5 - w, 0.5 - w, 0.5 - w, 0.5 + w, 0.5 + w, 0.5 + w)
  for (s <- 0 until 6)
    boxes(s) = new Cuboid6(0.5 - w, 0, 0.5 - w, 0.5 + w, 0.5 - w, 0.5 + w).apply(Rotation.sideRotations(s).at(Vector3.center))
  boxes
}

def case4mine() = {
  val w = 2 / 8D
  val (m, p) = (.5 - w, .5 + w)
  ((for (s <- 0 until 6) yield new Cuboid6(m, 0, m, p, m, p).apply(Rotation.sideRotations(s).at(Vector3.center)))
    :+ new Cuboid6(m, m, m, p, p, p)).toArray
}

verify("4", case4orig, case4mine)