<?php

	// tmMapLegend 1.0 PHP4 class
	// Jeffrey Barke <jeffrey.barke@themechanism.com>
	// 2008-04-02

	// This code is public domain <http://creativecommons.org/licenses/publicdomain/>

	// Based on the Palette class by Vladimir Guzmán <http://www.phpclasses.org/browse/package/3035.html>
	// Adaptación del código de steve@slayeroffice.com
	// http://slayeroffice.com/tools/color_palette/
	// Basado a su vez en una idea de Andy Clarke:
	// http://www.stuffandnonsense.co.uk/archives/creating_colour_palettes.html 

	class tmMapLegend {

		// default to text encoding <http://code.google.com/apis/chart/#text>
		var $strDataFormat = 'text';

		// simple encoding <http://code.google.com/apis/chart/#simple>
		var $arrEnc = array('A' => 0, 'B' => 1, 'C' => 2, 'D' => 3, 'E' => 4, 'F' => 5, 'G' => 6, 
			'H' => 7, 'I' => 8, 'J' => 9, 'K' => 10, 'L' => 11, 'M' => 12, 'N' => 13, 'O' => 14, 
			'P' => 15, 'Q' => 16, 'R' => 17, 'S' => 18, 'T' => 19, 'U' => 20, 'V' => 21, 'W' => 22, 
			'X' => 23, 'Y' => 24, 'Z' => 25, 'a' => 26, 'b' => 27, 'c' => 28, 'd' => 29, 'e' => 30, 
			'f' => 31, 'g' => 32, 'h' => 33, 'i' => 34, 'j' => 35, 'k' => 36, 'l' => 37, 'm' => 38, 
			'n' => 39, 'o' => 40, 'p' => 41, 'q' => 42, 'r' => 43, 's' => 44, 't' => 45, 'u' => 46, 
			'v' => 47, 'w' => 48, 'x' => 49, 'y' => 50, 'z' => 51, '0' => 52, '1' => 53, '2' => 54, 
			'3' => 55, '4' => 56, '5' => 57, '6' => 58, '7' => 59, '8' => 60, '9' => 61 );

		// constructor

		function tmMapLegend($strDataFormat = false) {
			// set data encoding
			if ($strDataFormat != false) { $this->strDataFormat = $strDataFormat; }
		}

		// public methods

		function getColor($intVal, $hexGradStart, $hexGradEnd, $hexGradTri = false) {
			return $this->process($intVal, $hexGradStart, $hexGradEnd, $hexGradTri);
		}

		function getRamp($arrVal, $hexGradStart, $hexGradEnd, $hexGradTri = false) {
			$output = array();
			foreach ($arrVal as $val) {
				array_push($output, $this->process($val, $hexGradStart, $hexGradEnd, $hexGradTri));
			}
			return $output;
		}

		function setEncType($strDataFormat) {
			$this->strDataFormat = $strDataFormat;
		}

		// private methods

		function process($intVal, $hexGradStart, $hexGradEnd, $hexGradTri = false) {
			// determine percent of range
			if ($this->strDataFormat == 'simple') {
				// convert passed val from simple encoding to integer
				$intVal = $this->arrEnc[$intVal];
				$intMid = 30;
				$intTop = 61;
			} else {
				$intMid = 50.0;
				$intTop = 100.0;
			}
			// if zero, return bottom of gradient
			if ($intVal == 0) { return strtolower($hexGradStart); }
			// two or three color ramps handled differently
			if ($hexGradTri == false) {
				$fltPercent = $intVal / $intTop;
			} else {
				// if middle, return middle of gradient
				if ($intVal == $intMid) { return strtolower($hexGradEnd); }
				// three color ramp really just two two color ramps
				if ($intVal > $intMid) {
					$fltPercent = $intVal / $intTop;
					$hexGradStart = $hexGradEnd;
					$hexGradEnd = $hexGradTri;
				} else {
					$fltPercent = $intVal / $intMid;
				}
			}
			// convert hex vals to decimal arrays
			if (strlen($hexGradStart) == 3) { $hexGradStart .= $hexGradStart; }
			$rgbStart = $this->longHexToDec(strtoupper($hexGradStart));
			if (strlen($hexGradEnd) == 3) { $hexGradEnd .= $hexGradEnd; }
			$rgbEnd = $this->longHexToDec(strtoupper($hexGradEnd));
			// calculate new color
			$rgbOutput = $this->setColorHue($rgbStart, $fltPercent, $rgbEnd);
			// return new hex value
			return $this->decToLongHex($rgbOutput);
		}

		function decToLongHex($rgb) {
			$r = str_pad(dechex($rgb[0]), 2, '0', STR_PAD_LEFT);
			$g = str_pad(dechex($rgb[1]), 2, '0', STR_PAD_LEFT);
			$b = str_pad(dechex($rgb[2]), 2, '0', STR_PAD_LEFT);
			return($r . $g . $b);
		}

		function longHexToDec($hex) {
			$r = hexdec(substr($hex, 0, 2));
			$g = hexdec(substr($hex, 2, 2));
			$b = hexdec(substr($hex, 4, 2));
			return array($r, $g, $b);
		}

		 function setColorHue($rgbStart, $fltPercent, $rgbEnd) {
		 	$rgbOutput = array();
		 	for ($i = 0; $i < 3; $i++) { $rgbOutput[$i] = floor($rgbStart[$i] * (1.0 - $fltPercent)) + round($rgbEnd[$i] * ($fltPercent)); }
			return $rgbOutput;
		 }

	}

?>