package com.olegchir.vectorperf

import scala.collection.mutable.ArrayBuffer

object Main {
  private class Vector2D (var x: Double, val y: Double) {

    def add(v : Vector2D) = {
      new Vector2D(v.x,v.y)
    }

    def mult(t:Transform2D):Vector2D = {
      new Vector2D(x * t.cos - y * t.sin + t.tx, y * t.sin + y * t.cos + t.ty)
    }

    override def toString = "Vector2D(" + "x=" + x + ", y=" + y + ')'
  }

  private class Transform2D (val angle: Double, val tx: Double, val ty: Double) {
    val cos: Double = Math.cos(angle)
    val sin: Double = Math.sin(angle)
  }

  private class VectorOfVector2D(private val size: Int) {
    private val buffer = new ArrayBuffer[Double](2 * size)
    def length() = size

    def get(idx: Int): Vector2D = new Vector2D(buffer.apply(idx * 2), buffer.apply(idx * 2 + 1))

    def add(v: Vector2D): Unit = {
      buffer+=v.x
      buffer+=v.y
    }

    def set(idx: Int, v: Vector2D): Unit = {
      buffer.update(2 * idx, v.x)
      buffer.update(2 * idx + 1, v.y)
    }
  }

  private def calc(v: VectorOfVector2D, t: Transform2D): Vector2D = {
    val res = new Vector2D(0, 0)
    for (i <- 0 until v.length()) {
      res.add(v.get(i).mult(t))
    }
    res
  }

  private def run(str: String, vects: VectorOfVector2D, transf: Transform2D): Unit = {
    println("Start of " + str)
    var vector: Vector2D = null
    val repeat = 1000
    val started = System.nanoTime()
    for (i <- 0 until repeat) {
      vector = calc(vects, transf)
    }
    val totalTime = (System.nanoTime() - started) * 1e-9
    println("Res = " + vector)
    println("Total time = " + totalTime + " (sec)")
    println("Average time = " + totalTime / repeat + " (sec)")
    println("End of " + str)
  }


  def main(a: Array[String]) = {
    val size = 1000000
    val vects = new VectorOfVector2D(size)

    for (i <- 0 until size) {
      val d = (1.0 * i) / size
      //vects.set(i, new Vector2D(d, d))
      vects.add(new Vector2D(d, d))
    }

    val transf = new Transform2D(1.0, -2.5, 5.0);
    run("Warm Up", vects, transf)
    println
    run("Actual", vects, transf)
  }
}