Рисование кривых Безье

<?php
set_time_limit(100);
 
define('GRAPH_WIDTH',  500);
define('GRAPH_HEIGHT', 400);
 
include_once ('classes/Plot.php');
include_once ('classes/CubicSplines.php');
include_once ('classes/SmoothCurve.class.php');
include_once ('classes/BezierCurve.class.php');
 
$iPoints = 5;
$dx = (GRAPH_WIDTH - 40) / ($iPoints - 1);
$x = 20;
 
for ($i = 0; $i < $iPoints; $i++) {
   $y = rand(20, GRAPH_HEIGHT - 20);
   $aCoords[$x] = $y;
   $x+= $dx;
    
}
$vImagegHeight = GRAPH_HEIGHT + 30;
$vImage = imagecreatetruecolor(GRAPH_WIDTH + 50, $vImagegHeight);
 
$vBgColor = imagecolorallocate($vImage, 160, 160, 160);
$vTextColor = imagecolorallocate($vImage, 0, 0, 0);
$vAxisColor = imagecolorallocate($vImage, 0, 0, 0);
$vDotColor  = imagecolorallocate($vImage, 192, 64, 64);
 
imagefill($vImage, 0, 0, $vBgColor);
 
$oPlot = new Plot($aCoords);
$oPlot->drawDots($vImage, $vDotColor, 10, GRAPH_HEIGHT, 8);
 
$oCurve = new CubicSplines();
$vColor = imagecolorallocate($vImage, 225, 64, 64);
 
$oBizie = new BezierCurve();
$colors = imagecolorallocate($vImage, 64, 192, 192);
$titles = 'Bezier curve';
 
$iStart = microtime(1);
 
    $start = microtime(1);
    if ($oBizie)
    {
        $oBizie->setCoords($aCoords, 1);
        $r = $oBizie->process();
        if($r) $curveGraph = new Plot($r);
        else continue;
    }
    else
    {
        $curveGraph = $oBizie;
    }
 
 
    unset($oBizie);
 
  $curveGraph->drawLine($vImage, $vColor, 10, GRAPH_HEIGHT);
   
 
 
 
$sTime = sprintf("%1.4f", microtime(1) - $iStart);
 
imagefilledrectangle($vImage, 0, GRAPH_HEIGHT, GRAPH_WIDTH + 50, $vImagegHeight, $vBgColor);
 
$oPlot->drawAxis($vImage, $vAxisColor, 10, GRAPH_HEIGHT);
$iPanelY = GRAPH_HEIGHT;
 
imagefilledrectangle($vImage, 10, $iPanelY + 10, 20, $iPanelY + 20, $vColor);
imagerectangle($vImage, 10, $iPanelY + 10, 20, $iPanelY + 20, $vAxisColor);
imagettftext($vImage, 10, 0, 30, $iPanelY + 20, $vTextColor, 'Ds-digib.ttf', 'Кубические сплайны в PHP:         ' . $sTime . ' sec');
 
header("Content-type: image/png");
imagepng($vImage);
imagedestroy($vImage);
?>