<?php
/*=====================================================================*\
|| ###################################################################
|| # Blue Static ISSO Framework
|| # Copyright Š2002-[#]year[#] Blue Static
|| #
|| # This program is free software; you can redistribute it and/or modify
|| # it under the terms of the GNU General Public License as published by
|| # the Free Software Foundation; version [#]gpl[#] of the License.
|| #
|| # This program is distributed in the hope that it will be useful, but
|| # WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|| # or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
|| # more details.
|| #
|| # You should have received a copy of the GNU General Public License along
|| # with this program; if not, write to the Free Software Foundation, Inc.,
|| # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
|| ###################################################################
\*=====================================================================*/

/**
* Graphing system: pie chart
* graph_pie.php
*
* @package	ISSO
*/

/**
* Graphing System: Pie Chart
*
* This framework creates pie charts as PNG image strings. Simply add to
* the data set and graph to get the byte stream returned.
*
* @author		Blue Static
* @copyright	Copyright Š2002 - [#]year[#], Blue Static
* @version		$Revision$
* @package		ISSO
* 
*/
class Graph_Pie
{
	/**
	* Framework registry object
	* @var	object
	* @access	private
	*/
	var $registry = null;
	
	/**
	* Graphing data set; 2D array of
	* array(NAME, PERCENT, COLOR)
	* @var	array
	* @access	private
	*/
	var $dataset = array();
	
	/**
	* Image resource
	* @var	resource
	* @access	private
	*/
	var $image = null;
	
	/**
	* The dimensions of the image
	* @var	array
	* @access	private
	*/
	var $dimensions = array('width' => 550, 'height' => 350);
	
	/**
	* Add a legend to the graph
	* @var	bool
	* @access	private
	*/
	var $legend = true;
	
	/**
	* Title of the graph
	* @var	string
	* @access	private
	*/
	var $title = 'ISSO Pie Chart';
	
	// ###################################################################
	/**
	* Constructor
	*/
	function __construct(&$registry)
	{
		$this->registry =& $registry;
		
		$this->set_scale(0);
	}
	
	// ###################################################################
	/**
	* (PHP 4) Constructor
	*/
	function Graph_Pie(&$registry)
	{
		$this->__construct($registry);
	}
	
	// ###################################################################
	/**
	* Graphs the actual graph and returns a byte stream
	*
	* @access	public
	*
	* @return	string	Byte stream
	*/
	function graph()
	{
		$colours['black'] = imagecolorallocate($this->image, 0, 0, 0);
		$colours['white'] = imagecolorallocate($this->image, 255, 255, 255);
		$colours['grey'] = imagecolorallocate($this->image, 121, 121, 123);
		
		$graphpadding = 10;
		$graphspacing = 4;
		$diameter = $this->dimensions['height'] - (5 * $graphpadding);
		$radius = $diameter / 2;
		$graphstart = $graphpadding + imagefontheight(5) + $graphpadding;
		$legendbox = 10;
		
		// fill background
		imagefill($this->image, 0, 0, $colours['white']);
		
		// title the chart
		imagestring($this->image, 5, ($this->dimensions['width'] - (imagefontwidth(5) * strlen($this->title))) / 2, $graphpadding, $this->title, $colours['black']);
		
		$center = array(
			'x' => ($this->legend ? ($radius + $graphpadding) : ($this->dimensions['width'] / 2)),
			'y' => ($this->dimensions['height'] / 2) + $graphpadding
		);
		
		// draw a border
		imageline($this->image, 0, 0, 0, $this->dimensions['height'], $colours['black']); // left
		imageline($this->image, 0, $this->dimensions['height'] - 1, $this->dimensions['width'], $this->dimensions['height'] - 1, $colours['black']); // bottom
		imageline($this->image, $this->dimensions['width'] - 1, 0, $this->dimensions['width'] - 1, $this->dimensions['height'], $colours['black']); // right
		imageline($this->image, 0, 0, $this->dimensions['width'], 0, $colours['black']); // top
		
		$legx = (2 * $graphpadding) + $diameter;
		
		$lastdeg = 0;
		$boxoffset = 0;
		foreach ($this->dataset AS $plot)
		{
			$deg = (360 / 100) * $plot[1];
			imagefilledarc($this->image, $center['x'], $center['y'], $diameter, $diameter, $lastdeg, $deg + $lastdeg, $plot[2], IMG_ARC_PIE);
			imagefilledarc($this->image, $center['x'], $center['y'], $diameter, $diameter, $lastdeg, $deg + $lastdeg, $colours['grey'], IMG_ARC_EDGED | IMG_ARC_NOFILL);
			$lastdeg += $deg;
			
			if ($this->legend)
			{
				$box = array(
					$legx + 1 + $graphspacing,				$graphstart + 1 + $graphspacing + $boxoffset, // top left
					$legx + 1 + $graphspacing,				$graphstart + 1 + $graphspacing + $boxoffset + $legendbox, // bottom left
					$legx + 1 + $graphspacing + $legendbox,	$graphstart + 1 + $graphspacing + $boxoffset + $legendbox, // bottom right
					$legx + 1 + $graphspacing + $legendbox,	$graphstart + 1 + $graphspacing + $boxoffset // top right
				);
				imagefilledpolygon($this->image, $box, 4, $plot[2]);
				
				imagestring($this->image, 2, ($legx + 1 + $graphspacing + $legendbox + $graphspacing), ($graphstart + $graphspacing + $boxoffset), $plot[0] . " ($plot[1]%)", $colours['black']);
				
				$boxoffset += $graphspacing + $legendbox;
			}
		}
		
		// draw the ellipse (do here so it cleans up the arc edges)
		imageellipse($this->image, $center['x'], $center['y'], $diameter, $diameter, $colours['grey']);
		
		// do the legend
		if ($this->legend)
		{
			imageline($this->image, $legx, $graphstart, $this->dimensions['width'] - $graphpadding, $graphstart, $colours['black']); // top
			imageline($this->image, $legx, $graphstart, $legx, $legy = ($graphstart + $graphspacing + $boxoffset + 1), $colours['black']); // left
			imageline($this->image, $legx, $legy, $this->dimensions['width'] - $graphpadding, $legy, $colours['black']); // bottom
			imageline($this->image, $this->dimensions['width'] - $graphpadding, $graphstart, $this->dimensions['width'] - $graphpadding, $legy, $colours['black']); // right
		}
		
		ob_start();
		imagepng($this->image);
		$data = ob_get_contents();
		if ($data === false)
		{
			$data = ob_get_clean();
		}
		ob_clean();
		ob_end_clean();
		
		return $data;
	}
	
	// ###################################################################
	/**
	* Sets the width and height by using scale factors of 550x350; you
	* can specify a positive value to multiply by that many times or a
	* negative one to divide
	*
	* @access	public
	*
	* @param	float	Scale factor
	*/
	function set_scale($scale)
	{
		$this->dimensions['width'] = 550;
		$this->dimensions['height'] = 350;
		
		if ($scale > 0)
		{
			$this->dimensions['width'] *= $scale;
			$this->dimensions['height'] *= $scale;
		}
		else if ($scale < 0)
		{
			$scale = abs($scale);
			$this->dimensions['width'] /= $scale;
			$this->dimensions['height'] /= $scale;
		}
		
		if (!is_null($this->image))
		{
			imagedestroy($this->image);
		}
		
		$this->image = imagecreate($this->dimensions['width'], $this->dimensions['height']);
	}
	
	// ###################################################################
	/**
	* Sets whether or not a legend is created for the graph
	*
	* @access	public
	*
	* @param	bool	Draw a legend?
	*/
	function set_legend($yesno)
	{
		$this->legend = (bool)$yesno;
	}
	
	// ###################################################################
	/**
	* Sets the title of the chart to be drawn above the graph
	*
	* @access	public
	*
	* @param	string	Title of the chart
	*/
	function set_title($title)
	{
		$this->title = $title;
	}
	
	// ###################################################################
	/**
	* Adds an entry to the data set without specifying a colour to add.
	* This is the standard method as the colour should only be overridden
	* if necessary.
	*
	* @access	public
	*
	* @param	string	Data column name
	* @param	integer	Percentage of 100
	*/
	function add_data_set($name, $percent)
	{
		$this->dataset[] = array($name, intval($percent), $this->fetch_colour());
	}
	
	// ###################################################################
	/**
	* Adds an entry ot the data set with specifying a colour. This works
	* the same as add_data_st() but requires an array() as the 3rd parameter
	* of R,G,B values
	*
	* @access	public
	*
	* @param	string	Data column name
	* @param	integer	Percent of 100
	* @param	array	Array of R,G,B values
	*/
	function add_data_set_colour($name, $percent, $colour)
	{
		$this->dataset[] = array($name, intval($percent), imagecolorallocate($this->image, $colour[0], $colour[1], $colour[2]));
	}
	
	// ###################################################################
	/**
	* Fetches a colour from the allocated colour list and returns the value
	*
	* @access	private
	*
	* @return	integer	Allocated colour resource
	*/
	function fetch_colour()
	{
		static $colourlist = array(
			array(100,	60,		175),
			array(221,	110,	21),
			array(179,	34,		31),
			array(69,	196,	243),
			array(128,	186,	33),
			array(28,	101,	155),
			array(246,	204,	95),
			array(6,	43,		147),
			array(204,	61,		7),
			array(170,	169,	174),
			array(90,	15,		24),
			array(45,	130,	195)
		);
		static $allocated = 0;
		
		$colour = $colourlist["$allocated"];
		$allocated++;
		
		return imagecolorallocate($this->image, $colour[0], $colour[1], $colour[2]);
	}
}

/*=====================================================================*\
|| ###################################################################
|| # $HeadURL$
|| # $Id$
|| ###################################################################
\*=====================================================================*/
?>