Author: ToneDJCampbell

<?php

/**
 * draw_triangle
 *
 * Draw a filled triangle.
 *
 * @version 0.4
 * @author Contributors at eXorithm
 * @link /algorithm/view/draw_triangle Listing at eXorithm
 * @link /algorithm/history/draw_triangle History at eXorithm
 * @license /home/show/license
 *
 * @param array $points This should be a list of six numbers that define the points of the triange (x1, y1, x2, y2, x3, y3)
 * @param string $color (hex color code) The color of the triangle
 * @return resource GD image
 */
function draw_triangle($points=array(0=>'0',1=>'0',2=>'0',3=>'8',4=>'8',5=>'4'),$color='000000')
{
	if (count($points)!=6) {
		throw new Exception('The points must be an array of 6 integers.');
	}
	
	$image = image_create_alpha(max($points[0], $points[2], $points[4])+1, max($points[1], $points[3], $points[5])+1);
	
	$red = hexdec(substr($color, 0, 2));
	$green  = hexdec(substr($color, 2, 2));
	$blue  = hexdec(substr($color, 4, 2));
		
	$color = imagecolorallocatealpha($image, $red, $green, $blue, 0);
	
	imagefilledpolygon($image, $points, 3, $color);
	
	return $image;
}

/**
 * image_create_alpha
 *
 * Helper function to create a new blank image with transparency.
 *
 * @version 0.1
 * @author Contributors at eXorithm
 * @link /algorithm/view/image_create_alpha Listing at eXorithm
 * @link /algorithm/history/image_create_alpha History at eXorithm
 * @license /home/show/license
 *
 * @param mixed $width 
 * @param mixed $height 
 * @return resource GD image
 */
function image_create_alpha($width='',$height='')
{
	// Create a normal image and apply required settings
	$img = imagecreatetruecolor($width, $height);
	imagealphablending($img, false);
	imagesavealpha($img, true);
	
	// Apply the transparent background
	$trans = imagecolorallocatealpha($img, 0, 0, 0, 127);
	for ($x = 0; $x < $width; $x++)
	{
		for ($y = 0; $y < $height; $y++)
		{
			imagesetpixel($img, $x, $y, $trans);
		}
	}
	
	return $img;
}

?>