<?php
header("Content-Type: image/png");

//IMAGE RELATED INIT
$lengthOfImage = 500;
$image = imagecreate(500,500);
$backgroundColour = imagecolorallocate($image,240,240,240);
$lineColour = imagecolorallocate($image,0,255,0);
$circleColour = imagecolorallocate($image,255,0,0);

imagefill($image,0,0,$backgroundColour);

//MATH RELATED INIT


function GetInsideAngleByNumberOfSides($sides) {
	return 180 - ((($sides-2)*180)/$sides);
}
define("DEG_TO_RAD",M_PI/180);
//$insideAngle = GetInsideAngleByNumberOfSides(lcg_value());
//$insideAngle -= $insideAngle%1.4;
$insideAngle = 2;

//$startDegrees = 200;
//$targetDegrees = 540;

$ox = $lengthOfImage/2;
$oy = $lengthOfImage/2;
//$radius = 75;
$innerradius = rand(1,100);
$outerradius = rand($innerradius,150);
$distance = rand($outerradius,200);
$max = 16000;

//$startx = $ox + (cos((90-$startDegrees)*DEG_TO_RAD)*$radius);
//$starty = $oy - (sin((90-$startDegrees)*DEG_TO_RAD)*$radius);
//$targetx = $ox + (cos((90-$targetDegrees)*DEG_TO_RAD)*$radius);
//$targety = $oy - (sin((90-$targetDegrees)*DEG_TO_RAD)*$radius);
//END INIT


//imageline($image,$ox,$oy,$startx,$starty,$lineColour);
//imageline($image,$ox,$oy,$targetx,$targety,$lineColour);
if(isset($_GET['sides'])) {
	if(floatval($_GET['sides']) != 0) {
		$insideAngle = GetInsideAngleByNumberOfSides(floatval($_GET['sides']));
	}
}
if(isset($_GET['angle'])) {
	if(floatval($_GET['angle']) != 0) {
		$insideAngle = floatval($_GET['angle']);
	}
}
if(isset($_GET['max'])) {
	$val = floatval($_GET['max']);
	if($val > 0 && $val <= 90000000) {
		$max = $val;
	}
}
if(isset($_GET['insideradius'])) {
	$val = floatval($_GET['insideradius']);
	if($val > 0 && $val <= 300) {
		$innerradius = $val;
	}
}
if(isset($_GET['outsideradius'])) {
	$val = floatval($_GET['outsideradius']);
	if($val > 0 && $val <= 300) {
		$outerradius = $val;
	}
}
if(isset($_GET['distance'])) {
	$val = floatval($_GET['distance']);
	if($val > 0 && $val <= 500) {
		$distance = $val;
	}
}

$radiusdifference = $outerradius-$innerradius;
$xfirsthalf = $radiusdifference * cos(0);
$xsecondhalf = $distance*cos(($radiusdifference/$innerradius)*(0));
$yfirsthalf = $radiusdifference * sin(0);
$ysecondhalf = $distance*sin(($radiusdifference/$innerradius)*(0));
$lastx = $ox + ($xfirsthalf + $xsecondhalf);
$lasty = $oy + ($yfirsthalf + $ysecondhalf);
$i=0;
//for($i=$startDegrees;$i<$targetDegrees;$i++) {
for($x=0;$x<$max;$x++) {
//while(true) {
	$i+= $insideAngle;
	$xfirsthalf = $radiusdifference * cos($i*DEG_TO_RAD);
	$xsecondhalf = $distance*cos(($radiusdifference/$innerradius)*($i*DEG_TO_RAD));
	$yfirsthalf = $radiusdifference * sin($i*DEG_TO_RAD);
	$ysecondhalf = $distance*sin(($radiusdifference/$innerradius)*($i*DEG_TO_RAD));
	$currentx = $ox + ($xfirsthalf + $xsecondhalf);
	$currenty = $oy - ($yfirsthalf + $ysecondhalf);

//      xfirsthalf = radiusdifference*Math.cos(0);
//		xsecondhalf = distance*Math.cos((radiusdifference/innerradius)*(0));
		
//		xval = xfirsthalf+xsecondhalf;


	imageline($image,$lastx,$lasty,$currentx,$currenty,$circleColour);
	if(($currentx == $lastx && $currenty == $lasty)) {
		break;
	}
	$lastx = $currentx;
	$lasty = $currenty;
	
	
}
imagestring($image,2,5,5,"Inside Angle (Usually 1-10 is useful) : ".$insideAngle,$circleColour);
imagestring($image,2,5,15,"Inside Radius (1-100) : ".$innerradius,$circleColour);
imagestring($image,2,5,25,"Outside Radius (1-150) : ".$outerradius,$circleColour);
imagestring($image,2,5,35,"Distance (1-200) : ".$distance,$circleColour);
imagepng($image);
imagedestroy($image);


?>