Trigonometry.php andTrigMain.php

TrigMain.php

<?php

include_once("Trigonometry.php");

header("Content-type: image/png");

function graphTrig()
{
    $trig = new Trigonometry();
    $setgraph = $trig->setGraph("cos");
    $width    = $trig->setWidth(400);
    $height   = $trig->setHeight(200);
    $setstart = $trig->setStartDegree(5);
    $setend   = $trig->setEndDegree(420);
    $trig->drawGraph();
}

echo graphTrig();

?>

Trigonometry.php

<?php

class Trigonometry
{
	// properties
	public $graph;
	public $height;
	public $width;
	public $startDegree;
	public $endDegree;
	public $errors = array();

	public function setGraph($graph)
	{
		switch ($this->graph)
		{
			case strtolower($this->graph == "sin"):
			     $this->graph = array();
			     $this->graph = array_push($this->graph, "sin");
			     break;
			case strtolower($this->graph == "cos"):
			     $this->graph = array_push($this->graph, "cos");
			     break;
			case strtolower($this->graph == "tan"):
			     $this->graph = array_push($this->graph, "tan");
			     break;          
		}

		$this->graph = $graph;
	}

	public function setWidth($width)
	{
		switch ($this->width)
		{
			case (!is_numeric($this->width)):
				 $errors[0] = "Width should be any number.";
				 print_r($this->errors[0]);
				 break;
            case $this->width >= 3000:
                 $errors[1] = "Width is too big.";
                 print_r($this->errors[1]);
                 break;
		}

		$this->width = $width;
	}

	public function setHeight($height)
	{
		switch ($this->height)
		{
			case (!is_numeric($this->height)):
				 $errors[2] = "Height should be any number.";
				 print_r($this->errors[2]);
				 break;
            case $this->height >= 3000:
                 $errors[3] = "Height is too big.";
                 print_r($this->errors[3]);
                 break;
		}

		$this->height = $height;
	}

	public function setStartDegree($startDegree)
	{
		switch ($this->startDegree)
		{
			case (!is_numeric($this->startDegree)):
			     $errors[4] = "Degree should be any number.";
			     print_r($this->errors[4]);
			     break;
			case (is_null($this->startDegree)):
			     $errors[5] = "Degree should be greater than 0.";
			     print_r($this->errors[5]);
			     break;     
		}

		$this->startDegree = $startDegree;
	}

	public function setEndDegree($endDegree)
	{
		switch ($this->endDegree)
		{
			case (!is_numeric($this->endDegree)):
			     $errors[6] = "Degree should be any number.";
			     print_r($this->errors[6]);
			     break;
			case (is_null($this->endDegree)):
			     $errors[7] = "Degree should be greater than 0.";
			     print_r($this->errors[7]);
			     break;     
		}
		
		$this->endDegree = $endDegree;
	}

	public function getGraph()
	{
		return $this->graph;
	}


	public function getWidth()
	{
		return $this->width;
	}

	public function getHeight()
	{
		return $this->height;
	}

	public function getEndDegree()
	{
		return $this->endDegree;
	}

	public function getStartDegree()
	{
		return $this->startDegree;
	}

	public function drawGraph()
	{
		$boxheight = $this->getHeight();
		$boxwidth = $this->getWidth();
		$startdeg = $this->getStartDegree();
		$enddeg = $this->getEndDegree();

        $offset = $boxheight/2;
        $area = imagecreatetruecolor($boxwidth, $boxheight);
        $col_poly = imagecolorallocate($area, 255, 255, 255);

        for ($c = $startdeg; $c < $enddeg; $c++)
        {
             $this_x = $c;
             $next_x = $this_x + 1;

             if ($this->getGraph() == "sin") {
                 $this_y = sin(deg2rad($this_x)) * $offset + $offset; 
                 $next_y = sin(deg2rad($next_x)) * $offset + $offset;
                 imageline($area, $this_x, $this_y, $next_x, $next_y, $col_poly);
             } else if ($this->getGraph() == "cos") {
                 $this_y = cos(deg2rad($this_x)) * $offset + $offset; 
                 $next_y = cos(deg2rad($next_x)) * $offset + $offset;
                 imageline($area, $this_x, $this_y, $next_x, $next_y, $col_poly);
             } else if ($this->getGraph() == "tan") {
             	 $this_y = tan(deg2rad($this_x)) * $offset + $offset; 
                 $next_y = tan(deg2rad($next_x)) * $offset + $offset;
                 imageline($area, $this_x, $this_y, $next_x, $next_y, $col_poly);
             }
        }
        imagepng($area);
        imagedestroy($area); 
	}
}

?>