<?php
/**
 *
 * HeatmapFromArray.class.php
 * Modified by Andreas K. Orphanides, NCSU Libraries
 *  from HeatmapFromDatabase.class.php in ClickHeat 1.11 by LabsMedia (www.labsmedia.com)
 *
 * Requires the file Heatmap.class.php from ClickHeat. 
 * Code below not tested with any version other than 1.11
 *
 * Comments in PHPdoc format, other than this introduction, are from the original author.
 * "//" style comments are from AKO.
 *
 * Revisions:
 * 2010-11-17   Modified HeatmapFromDatabase.php into this new file and tested.
 * 2011-09-01   Additional commentary added
 *
 *
 * -- original introductory comments below --
 *
 * ClickHeat : Classe de génération des cartes depuis une base de données MySQL / Maps generation class from a MySQL database
 * 
 * Cette classe est VOLONTAIREMENT écrite pour PHP 4
 * This class is VOLUNTARILY written for PHP 4
 * 
 * Utilisation : jettez un oeil au répertoire /examples/
 * Usage: have a look into /examples/ directory
 * 
 * @author Yvan Taviaud - LabsMedia - www.labsmedia.com
 * @since 19/05/2007
**/

class HeatmapFromArray extends Heatmap
{
	// An array of arrays, each of the form 0=>x,1=>y  - ako
	var $inputArray = array();
	/**
	 * Do some tasks before drawing (get max Y value - ako)
	**/
	function startDrawing()
	{
		
		// ClickHeat needs the maximum Y value for some reason (haven't actually investigated.)
		// Get Y dimensions from source array
		// - ako
		$ys = array();
		foreach ($this->inputArray as $coords) {
			$ys[]=$coords[1];
		}
		// Get max Y value from new array. -ako
		$this->maxY = max($ys);
		return true;
	}

	/**
	 * Find pixels coords and draw these on the current image
	 *
	 * @param integer $image Number of the image (to be used with $this->height)
	 * @return boolean Success
	**/
	function drawPixels($image)
	{
		foreach ($this->inputArray as $click)
		{
			$x = (int) $click[0];
			$y = (int) ($click[1]  - $image * $this->height);
			if ($x < 0 || $x >= $this->width)
			{
				continue;
			}
			/** Apply a calculus for the step, with increases the speed of rendering : step = 3, then pixel is drawn at x = 2 (center of a 3x3 square) */
			$x -= $x % $this->step - $this->startStep;
			$y -= $y % $this->step - $this->startStep;
			/** Add 1 to the current color of this pixel (color which represents the sum of clicks on this pixel) */
			$color = imagecolorat($this->image, $x, $y) + 1;
			imagesetpixel($this->image, $x, $y, $color);
			$this->maxClicks = max($this->maxClicks, $color);
			if ($image === 0)
			{
				/** Looking for the maximum height of click */
				$this->maxY = max($y, $this->maxY);
			}
		}
	}

	/**
	 * Do some cleaning or ending tasks (close database, reset array...)
	**/
	function finishDrawing()
	{
		/** Close connection */
		return true;
	}
}
?>