<?php

//код который долго считается
    $i = 0;
            $d0 = 1.0 / $noiseScale;
            $k = -1;
            $d1 = 0.0;
            $d2 = 0.0;
            $d3 = 0.0;
            $d4 = 0.0;

            for ($l2 = 0; $l2 < $xSize; ++$l2) {
                $d5 = $xOffset + (float)$l2 * $xScale + $this->xCoord;
                $i3 = (int)$d5;

                if ($d5 < (float)$i3) {
                    --$i3;
                }

                $j3 = $i3 & 255;
                $d5 = $d5 - (float)$i3;
                $d6 = $d5 * $d5 * $d5 * ($d5 * ($d5 * 6.0 - 15.0) + 10.0);

                for ($k3 = 0; $k3 < $zSize; ++$k3) {
                    $d7 = $zOffset + (float)$k3 * $zScale + $this->zCoord;
                    $l3 = (int)$d7;

                    if ($d7 < (float)$l3) {
                        --$l3;
                    }

                    $i4 = $l3 & 255;
                    $d7 = $d7 - (float)$l3;
                    $d8 = $d7 * $d7 * $d7 * ($d7 * ($d7 * 6.0 - 15.0) + 10.0);

                    for ($j4 = 0; $j4 < $ySize; ++$j4) {
                        $d9 = $yOffset + (float)$j4 * $yScale + $this->yCoord;
                        $k4 = (int)$d9;

                        if ($d9 < (float)$k4) {
                            --$k4;
                        }

                        $l4 = $k4 & 255;
                        $d9 = $d9 - (float)$k4;
                        $d10 = $d9 * $d9 * $d9 * ($d9 * ($d9 * 6.0 - 15.0) + 10.0);

                        if ($j4 == 0 || $l4 != $k) {
                            $k = $l4;
                            $l = $this->permutations[$j3] + $l4;
                            $i1 = $this->permutations[$l] + $i4;
                            $j1 = $this->permutations[$l + 1] + $i4;
                            $k1 = $this->permutations[$j3 + 1] + $l4;
                            $l1 = $this->permutations[$k1] + $i4;
                            $i2 = $this->permutations[$k1 + 1] + $i4;
                            $d1 = $this->lerp($d6, $this->grad($this->permutations[$i1], $d5, $d9, $d7), $this->grad($this->permutations[$l1], $d5 - 1.0, $d9, $d7));
                            $d2 = $this->lerp($d6, $this->grad($this->permutations[$j1], $d5, $d9 - 1.0, $d7), $this->grad($this->permutations[$i2], $d5 - 1.0, $d9 - 1.0, $d7));
                            $d3 = $this->lerp($d6, $this->grad($this->permutations[$i1 + 1], $d5, $d9, $d7 - 1.0), $this->grad($this->permutations[$l1 + 1], $d5 - 1.0, $d9, $d7 - 1.0));
                            $d4 = $this->lerp($d6, $this->grad($this->permutations[$j1 + 1], $d5, $d9 - 1.0, $d7 - 1.0), $this->grad($this->permutations[$i2 + 1], $d5 - 1.0, $d9 - 1.0, $d7 - 1.0));
                        }

                        $d11 = $this->lerp($d10, $d1, $d2);
                        $d12 = $this->lerp($d10, $d3, $d4);
                        $d13 = $this->lerp($d8, $d11, $d12);
                        $j7 = $i++;

                        $noiseArray[$j7] += ($d13 * $d0);
                    }
                }
            }





//functions
/**
     * @param $a
     * @param $b
     * @param $c
     * @return float|int
     */
    function lerp($a, $b, $c)
    {
        return $b + $a * ($c - $b);
    }

    /**
     * @param $a
     * @param $b
     * @param $c
     * @return float|int
     */
    function grad2($a, $b, $c)
    {
        $i = $a & 15;
        return self::GRAD_2X[$i] * $b + self::GRAD_2Z[$i] * $c;
    }

    /**
     * @param $a
     * @param $b
     * @param $c
     * @param $d
     * @return float|int
     */
    function grad($a, $b, $c, $d)
    {
        $i = $a & 15;
        return self::GRAD_X[$i] * $b + self::GRAD_Y[$i] * $c + self::GRAD_Z[$i] * $d;
    }
?>