<?php 
///////////////////////////////////////////////////////////
//PHPGraphLib -  PHP Graphing Library v2.31
//Author: Elliott Brueggeman
//PHP v4.04 + compatible
//Please visit www.ebrueggeman.com for usage policy
//and full documentation + examples
///////////////////////////////////////////////////////////
class PHPGraphLib {
	//---------------user changeable defaults----------------/
	var $height = 300;
	var $width = 400;
	var $data_max_allowable = 9999999999999999;
	var $data_min_allowable = -9999999999999999;
	var $data_set_count = 0;
	//set to actual font heights and widths used
	var $title_char_width = 6;
	var $title_char_height = 12;
	var $text_width = 6;
	var $text_height = 12;
	var $data_value_text_width = 6;
	var $data_value_text_height = 12;
	//padding between axis and value displayed
	var $axis_value_padding = 5;
	//space b/t top of bar or center of point and data value
	var $data_value_padding = 5; 
	//default margin % of width / height
	var $x_axis_default_percent = 12; 
	var $y_axis_default_percent = 8;
	//data point diameter in px
	var $data_point_width = 6;
	//user changeable default booleans (show element by default?)
	var $bool_bar_outline = true;
	var $bool_x_axis = true;
	var $bool_y_axis = true;
	var $bool_x_axis_values = true;
	var $bool_y_axis_values = true;
	var $bool_grid = true;
	var $bool_line = false;
	var $bool_data_values = false;
	var $bool_x_axis_values_vert = true;
	var $bool_data_points = false;
	var $bool_title_left = false;
	var $bool_title_right = false;
	var $bool_title_center = true;
	//----------internal variables (do not change)------------/
	var $image;
	var $output_file;
	var $error;
	var $bool_x_axis_setup = false;
	var $bool_y_axis_setup = false;
	var $bool_data = false;
	var $bool_bars_generate = true;
	var $bool_bars = true;
	var $bool_background = false;
	var $bool_title = false;
	var $bool_all_negative = false;
	var $bool_all_positive = false;
	var $bool_gradient = false;
	var $bool_user_data_range = false;
	var $all_zero_data = false;
	var $bool_gradient_colors_found; //init as array
	//color vars
	var $background_color;
	var $grid_color;
	var $bar_color;
	var $outline_color;
	var $x_axis_text_color;
	var $y_axis_text_color;
	var $title_color;
	var $x_axis_color;
	var $y_axis_color;
	var $data_point_color;
	var $data_value_color;
	var $line_color;
	var $line_color_default;
	var $goal_line_color;
	var $goal_line_color_custom;
	//gradient colors stored as arrays, not allocated color
	var $gradient_color_1;
	var $gradient_color_2;
	var $gradient_color_array;
	var $gradient_max = 200;
	var $gradient_handicap;
	//data vars
	var $data_array;
	var $data_count;
	var $data_min;
	var $data_max;
	var $true_displayed_max_value;
	var $true_displayed_min_value;
	var $data_currency;
	var $data_format_array;
	var $data_additional_length = 0;
	var $data_format_generic;
	//bar vars / scale
	var $bar_spaces;
	var $bar_width;
	var $space_width;
	var $unit_scale;
	var $goal_line_array;
	var $horiz_grid_lines;
	var $vert_grid_lines;
	var $horiz_grid_values;
	var $vert_grid_values;
	//text / font
	var $title_x;
	var $title_y;
	//axis points
	var $x_axis_x1;
	var $x_axis_y1;
	var $x_axis_x2;
	var $x_axis_y2;
	var $y_axis_x1;
	var $y_axis_y1;
	var $y_axis_x2;
	var $y_axis_y2;
	var $x_axis_margin; //aka bottom margin
	var $y_axis_margin; //aka left margin
	var $data_range_max;
	var $data_range_min;
	var $top_margin = 0;
	var $right_margin = 0;
	var $range_divisor_factor = 25; //controls auto-adjusting grid interval
	var $data_point_array;
	//multiple dataset variables
	var $bool_multi_offset = true;
	var $multi_offset_two = 24; //percent of bar width
	var $multi_offset_three = 15; //percent of bar width
	var $multi_offset_four = 10; //percent of bar width
	var $multi_offset_five = 9; //percent of bar width
	var $multi_gradient_colors_1;
	var $multi_gradient_colors_2;
	var $multi_bar_colors;
	var $color_darken_factor = 30;//percent decrease
	//legend variables
	var $bool_legend = false;
	var $legend_text_width = 6; //in px...
	var $legend_max_chars = 15; 
	var $legend_total_chars; 
	var $legend_text_height = 12;
	var $legend_padding=4; //padding inside legend box
	var $legend_width;
	var $legend_height;
	var $legend_x;
	var $legend_y;
	var $legend_text_color;
	var $legend_outline_color;
	var $legend_swatch_outline_color;
	var $legend_color;
	var $legend_titles = array();
	function PHPGraphLib($width = '', $height = '', $output_file = NULL) {
		if (!empty($width) && !empty($height)) {
			$this->width = $width;
			$this->height = $height;
		}
		$this->output_file = $output_file;
		$this->initialize();
		$this->allocateColors(); //sets default colors	
	}
	function initialize() {
		//header must be sent before any html or blank space output
		if (!$this->output_file){ header("Content-type: image/png"); }
		$this->image = @imagecreate($this->width, $this->height)
			or die("Cannot Initialize new GD image stream - Check your PHP setup");
		$this->data_point_array = array();
		$this->goal_line_array = array();
		$this->multi_bar_colors = array();
		$this->multi_gradient_colors_1 = array();
		$this->multi_gradient_colors_2 = array();
		//these values are now arrays
		$this->gradient_handicap = array();
		$this->bool_gradient_colors_found = array();
		$this->legend_total_chars = array();
		$this->line_color = array();
		$this->data_format_array = array();
		$this->horiz_grid_lines = array();
		$this->vert_grid_lines = array();
		$this->horiz_grid_values = array();
		$this->vert_grid_values = array();
	}
	function createGraph() {
		//main class method - called last
		//setup axis if not already setup by user
		if ($this->bool_data){
			if (!$this->bool_x_axis_setup){ $this->setupXAxis(); }
			if (!$this->bool_y_axis_setup){ $this->setupYAxis(); }
			//calculations
			$this->calcTopMargin();
			$this->calcRightMargin();
			$this->calcCoords();
			$this->setupData();
			//start creating actual image elements
			if ($this->bool_background){ $this->generateBackgound(); }
			//always gen grid values, even if not displayed
			$this->generateGrid();
			if ($this->bool_bars_generate){ $this->generateBars(); }
			if ($this->bool_data_points){ $this->generateDataPoints(); }
			if ($this->bool_legend){ $this->generateLegend(); }
			if ($this->bool_title){ $this->generateTitle(); }
			if ($this->bool_x_axis){ $this->generateXAxis(); }
			if ($this->bool_y_axis){ $this->generateYAxis(); }
		}
		else {
			$this->error[] = "No valid data added to graph. Add data with the addData() function.";
		}
		//display errors
		$this->displayErrors();
		//output to browser
		if ($this->output_file) {
			imagepng($this->image, $this->output_file);
		}
		else {
			imagepng($this->image);
		}
		imagedestroy($this->image);
	}
	function setupData() {
		$this->bar_spaces = ($this->data_count * 2) + 1;
		$unit_width = ($this->width - $this->y_axis_margin - $this->right_margin) / (($this->data_count * 2) + $this->data_count);
		if ($unit_width < 1) {	
			//error units too small, too many data points or not large enough graph
			$this->bool_bars_generate = false;
			$this->error[] = "Graph too small or too many data points.";
		}
		else {
			//default space between bars is 1/2 the width of the bar
			//find bar and space widths. bar = 2 units, space = 1 unit
			$this->bar_width= 2 * $unit_width;
			$this->space_width = $unit_width;		
			//now calculate height (scale) units
			$availVertSpace = $this->height - $this->x_axis_margin - $this->top_margin;	
			if ($availVertSpace<1) {
				$this->bool_bars_generate=false;
				$this->error[] = "Graph height not tall enough.";
				//error scale units too small, x axis margin too big or graph height not tall enough
			}
			else {
				if ($this->bool_user_data_range) {
					//if all zero data, set fake max and min to range boundaries
					if ($this->all_zero_data) {
						if ($this->data_range_min > $this->data_min) { $this->data_min = $this->data_range_min; }
						if ($this->data_range_max < $this->data_max) { $this->data_max = $this->data_range_max; }
					}

					$graphTopScale = $this->data_range_max;
					$graphBottomScale = $this->data_range_min;	
					$graphScaleRange = $graphTopScale - $graphBottomScale;
					$this->unit_scale = $availVertSpace / $graphScaleRange;			
					$this->data_max = $this->data_range_max;
					$this->data_min = $this->data_range_min;
					if ($this->data_min < 0) {
						$this->x_axis_y1 -= round($this->unit_scale * abs($this->data_min));
						$this->x_axis_y2 -= round($this->unit_scale * abs($this->data_min));
					}
					//all data identical
					if ($graphScaleRange == 0) {
						$graphScaleRange = 100;
					}
				}
				else {
					//start at y value 0 or data min, whichever is less
					$graphBottomScale = ($this->data_min<0) ? $this->data_min : 0;
					$graphTopScale = ($this->data_max<0) ? 0 : $this->data_max ;
					$graphScaleRange = $graphTopScale - $graphBottomScale;
					
					//all data identical
					if ($graphScaleRange == 0) {
						$graphScaleRange = 100;
					}
					$this->unit_scale = $availVertSpace / $graphScaleRange;			
					//now adjust x axis in y value if negative values
					if ($this->data_min < 0) {
						$this->x_axis_y1 -= round($this->unit_scale * abs($this->data_min));
						$this->x_axis_y2 -= round($this->unit_scale * abs($this->data_min));
					}
				}
				$this->bool_bars_generate = true;	
			}
		}
	}
	//always port changes to generatebars() to extensions
	function generateBars() {
		$this->finalizeColors();
		$barCount = 0;
		$adjustment = 0;
		if ($this->bool_user_data_range && $this->data_min >= 0) {
			$adjustment = $this->data_min * $this->unit_scale;
		}
		//reverse array to order data sets in order of priority
		$this->data_array = array_reverse($this->data_array);
		$dataset_offset=0;
		if ($this->bool_multi_offset) {
			//set different offsets based on number of data sets
			switch ($this->data_set_count) {
				case 2: $dataset_offset = $this->bar_width * ($this->multi_offset_two / 100); break;
				case 3: $dataset_offset = $this->bar_width * ($this->multi_offset_three / 100); break;
				case 4: $dataset_offset = $this->bar_width * ($this->multi_offset_four / 100); break;
				case 5: $dataset_offset = $this->bar_width * ($this->multi_offset_five / 100); break;
			}
		}
		foreach ($this->data_array as $data_set_num => $data_set) {
			$lineX2 = NULL;
			$xStart = $this->y_axis_x1 + ($this->space_width / 2);
			foreach ($data_set as $key => $item) {
				$hideBarOutline = false;

				$x1=round($xStart + ($dataset_offset * $data_set_num));
				$x2=round(($xStart + $this->bar_width) + ($dataset_offset * $data_set_num));

				$y1=round($this->x_axis_y1 - ($item * $this->unit_scale) + $adjustment);
				$y2=round($this->x_axis_y1);
				
				//if we are using a user specified data range, need to limit what's displayed
				if ($this->bool_user_data_range) {
					if ($item <= $this->data_range_min) {
						//don't display, we are out of our allowed display range!
						$y1 = $y2;
						$hideBarOutline = true;
					}
					else if ($item >= $this->data_range_max) {
						//display, but cut off display above range max
						$y1 = $this->x_axis_y1 - ($this->true_displayed_max_value * $this->unit_scale) + $adjustment;	
					}
				}	
				//draw bar 
				if ($this->bool_bars) {
					if ($this->bool_gradient) {
						//draw gradient if desired
						$this->drawGradientBar($x1, $y1, $x2, $y2, $this->multi_gradient_colors_1[$data_set_num], $this->multi_gradient_colors_2[$data_set_num], $data_set_num);
					}
					else {
						imagefilledrectangle($this->image, $x1, $y1,$x2, $y2,  $this->multi_bar_colors[$data_set_num]);
					}
					//draw bar outline	
					if ($this->bool_bar_outline && !$hideBarOutline) { 
						imagerectangle($this->image, $x1, $y2, $x2, $y1, $this->outline_color); 
					}
				}
				// draw line
				if ($this->bool_line) {
					$lineX1 = $x1 + ($this->bar_width / 2); //MIDPOINT OF BARS, IF SHOWN
					$lineY1 = $y1;
					if (isset($lineX2)) {
						imageline($this->image, $lineX2, $lineY2, $lineX1, $lineY1, $this->line_color[$data_set_num]);
						$lineX2 = $lineX1;
						$lineY2 = $lineY1;
					}
					else {
						$lineX2 = $lineX1;
						$lineY2 = $lineY1;
					}	
				}
				// display data points
				if ($this->bool_data_points) {
					//dont draw datapoints here or will overlap poorly with line
					//instead collect coordinates
					$pointX = $x1 + ($this->bar_width / 2); //MIDPOINT OF BARS, IF SHOWN
					$this->data_point_array[] = array($pointX, $y1);
				}
				// display data values
				if ($this->bool_data_values) {
					$dataX = ($x1 + ($this->bar_width / 2)) - ((strlen($item) * $this->data_value_text_width) / 2);
					//value to be graphed is equal/over 0
					if ($item >= 0) {
						$dataY = $y1 - $this->data_value_padding - $this->data_value_text_height;
					}
					else {
						//check for item values below user spec'd range
						if ($this->bool_user_data_range && $item <= $this->data_range_min) {
							$dataY = $y1 - $this->data_value_padding - $this->data_value_text_height;
						}
						else {
							$dataY = $y1 + $this->data_value_padding;
						}
					}
					//add currency sign, formatting etc
					if ($this->data_format_array) {
						$item = $this->applyDataFormats($item);
					}
					if ($this->data_currency) {
						$item = $this->applyDataCurrency($item);
					}
					//recenter data position if necessary
					$dataX -= ($this->data_additional_length * $this->data_value_text_width) / 2;
					imagestring($this->image, 2, $dataX, $dataY, $item,  $this->data_value_color);
				}
				//write x axis value 
				if ($this->bool_x_axis_values) {
					if ($data_set_num == $this->data_set_count - 1) {
						if ($this->bool_x_axis_values_vert) {
							if ($this->bool_all_negative) {
								//we must put values above 0 line
								$textVertPos = round($this->y_axis_y2 - $this->axis_value_padding);
							}
							else {
								//mix of both pos and neg numbers
								//write value y axis bottom value (will be under bottom of grid even if x axis is floating due to
								$textVertPos = round($this->y_axis_y1 + (strlen($key) * $this->text_width) + $this->axis_value_padding);
							}
							$textHorizPos = round($xStart + ($this->bar_width / 2) - ($this->text_height / 2));
							imagestringup($this->image, 2, $textHorizPos, $textVertPos, $key,  $this->x_axis_text_color);
						}
						else {
							if ($this->bool_all_negative) {
								//we must put values above 0 line
								$textVertPos = round($this->y_axis_y2 - $this->text_height - $this->axis_value_padding);
							}
							else {
								//mix of both pos and neg numbers
								//write value y axis bottom value (will be under bottom of grid even if x axis is floating due to
								$textVertPos = round($this->y_axis_y1 + ($this->text_height * 2 / 3) - $this->axis_value_padding);
							}
							//horizontal data keys
							$textHorizPos = round($xStart + ($this->bar_width / 2) - ((strlen($key) * $this->text_width) / 2));
							imagestring($this->image, 2, $textHorizPos, $textVertPos, $key,  $this->x_axis_text_color);
						}
					}
				}
				$xStart += $this->bar_width + $this->space_width;
			}
		}
	}
	function finalizeColors() {
		if ($this->bool_gradient) {
			$num_set=count($this->multi_gradient_colors_1);
			//loop through set colors and add backing colors if necessary
			if ($num_set != $this->data_set_count) {
				$color_darken_decimal = (100 - $this->color_darken_factor) / 100;
				while ($num_set < $this->data_set_count) {
					$color_ref_1 = $this->multi_gradient_colors_1[$num_set - 1];
					$color_ref_2 = $this->multi_gradient_colors_2[$num_set - 1];
					$this->multi_gradient_colors_1[] = array( 
						round($color_ref_1[0] * $color_darken_decimal), 
						round($color_ref_1[1] * $color_darken_decimal), 
						round($color_ref_1[2] * $color_darken_decimal));
					$this->multi_gradient_colors_2[]=array(
						round($color_ref_2[0] * $color_darken_decimal), 
						round($color_ref_2[1] * $color_darken_decimal), 
						round($color_ref_2[2] * $color_darken_decimal));
					$num_set++;
				}	
			}
			while (count($this->multi_gradient_colors_1) > $this->data_set_count) {
				$temp = array_pop($this->multi_gradient_colors_1);
			}
			while (count($this->multi_gradient_colors_2) > $this->data_set_count) {
				$temp = array_pop($this->multi_gradient_colors_2);
			}
			$this->multi_gradient_colors_1 = array_reverse($this->multi_gradient_colors_1);
			$this->multi_gradient_colors_2 = array_reverse($this->multi_gradient_colors_2);
		}
		else if (!$this->bool_gradient) {
			$num_set = count($this->multi_bar_colors);
			if ($num_set == 0) {
				$this->multi_bar_colors[0] = $this->bar_color;
				$num_set = 1;
			}
			//loop through set colors and add backing colors if necessary
			while ($num_set < $this->data_set_count) {
				$color_ref = $this->multi_bar_colors[$num_set - 1];
				$color_parts = imagecolorsforindex($this->image, $color_ref);
				$color_darken_decimal = (100 - $this->color_darken_factor) / 100;
				$this->multi_bar_colors[$num_set] = imagecolorallocate($this->image, 
					round($color_parts['red'] * $color_darken_decimal), 
					round($color_parts['green'] * $color_darken_decimal), 
					round($color_parts['blue'] * $color_darken_decimal));
				$num_set++;
			}
			while (count($this->multi_bar_colors) > $this->data_set_count) {
				$temp = array_pop($this->multi_bar_colors);
			}
			$this->multi_bar_colors = array_reverse($this->multi_bar_colors);
		}
		if ($this->bool_line) {
			if (!$this->bool_bars) {
				$num_set = count($this->line_color);
				if ($num_set == 0) {
					$this->line_color[0] = $this->line_color_default;
					$num_set = 1;
				}
				//only darken each data set's lines when no bars present
				while ($num_set < $this->data_set_count) {
					$color_ref = $this->line_color[$num_set - 1];
					$color_parts = imagecolorsforindex($this->image, $color_ref);
					$color_darken_decimal = (100 - $this->color_darken_factor) / 100;
					$this->line_color[$num_set] = imagecolorallocate($this->image, 
						round($color_parts['red'] * $color_darken_decimal), 
						round($color_parts['green'] * $color_darken_decimal), 
						round($color_parts['blue'] * $color_darken_decimal));
					$num_set++;
				}
			}
			else {
				$num_set = count($this->line_color);
				while ($num_set < $this->data_set_count) {
					$this->line_color[$num_set] = $this->line_color_default;
					$num_set++;
				}
			}
			while (count($this->line_color) > $this->data_set_count) {
				$temp = array_pop($this->line_color);
			}
			$this->line_color = array_reverse($this->line_color);
		}	
	}
	function drawGradientBar($x1, $y1, $x2, $y2, $colorArr1, $colorArr2, $data_set_num) {
		if (!isset($this->bool_gradient_colors_found[$data_set_num]) || $this->bool_gradient_colors_found[$data_set_num] == false) {
			$this->gradient_handicap[$data_set_num] = 0;
			$numLines = abs($x1 - $x2) + 1;
			while ($numLines * $this->data_set_count > $this->gradient_max) {
				//we have more lines than allowable colors
				//use handicap to record this
				$numLines /= 2;
				$this->gradient_handicap[$data_set_num]++;
			}
			$color1R = $colorArr1[0];
			$color1G = $colorArr1[1];
			$color1B = $colorArr1[2];
			$color2R = $colorArr2[0];
			$color2G = $colorArr2[1];
			$color2B = $colorArr2[2];
			$rScale = ($color1R-$color2R) / $numLines;
			$gScale = ($color1G-$color2G) / $numLines;
			$bScale = ($color1B-$color2B) / $numLines;
			$this->allocateGradientColors($color1R, $color1G, $color1B, $rScale, $gScale, $bScale, $numLines, $data_set_num);
		}
		$numLines = abs($x1 - $x2) + 1;
		if ($this->gradient_handicap[$data_set_num] > 0) {
			//if handicap is used, it will allow us to move through the array more slowly, depending on the set value
			$interval = $this->gradient_handicap[$data_set_num];
			for($i = 0; $i < $numLines; $i++) {
				$adjusted_index = ceil($i / pow(2, $interval)) - 1;
				if ($adjusted_index < 0) {
					$adjusted_index = 0;
				}
				imageline($this->image, $x1+$i, $y1, $x1 + $i, $y2, $this->gradient_color_array[$data_set_num][$adjusted_index]);		
			}
		}
		else {
			//normal gradients with colors < $this->gradient_max
			for ($i = 0; $i < $numLines; $i++) {
				imageline($this->image, $x1+$i, $y1, $x1+$i, $y2, $this->gradient_color_array[$data_set_num][$i]);		
			}
		}
	}
	function generateGrid() {
		if ($this->bool_user_data_range && $this->data_min >= 0) {
			$adjustment = $this->data_min * $this->unit_scale;
		}
		else {
			$adjustment = 0;
		}
		//calculate both values
		$this->calculateGridHoriz($adjustment);
		$this->calculateGridVert();
		//output values - separation from calc is b/c of an extension related need
		$this->generateGrids();
		$this->generateGoalLines($adjustment);
	}
	function calculateGridHoriz($adjustment = 0) {
		//determine horizontal grid lines
		$horizGridArray = array();
		if ($this->bool_user_data_range) {
			$min = $this->data_min;
		}
		else {
			$min = 0;
		}
		$horizGridArray[] = $min;
		//use our function to determine ideal y axis scale interval
		$intervalFromZero = $this->determineAxisMarkerScale($this->data_max, $this->data_min);
		//if we have positive values, add grid values to array 
		//until we reach the max needed (we will go 1 over)
		$cur = $min;
		while ($cur < $this->data_max) {
			$cur += $intervalFromZero;
			$horizGridArray[] = $cur;
		}
		//if we have negative values, add grid values to array 
		//until we reach the min needed (we will go 1 over)
		$cur = $min;
		while ($cur > $this->data_min) {
			$cur -= $intervalFromZero;
			$horizGridArray[] = $cur;
		}
		//sort needed b/c we will use last value later (max)
		sort($horizGridArray);
		$this->true_displayed_max_value = $horizGridArray[count($horizGridArray) - 1];
		$this->true_displayed_min_value = $horizGridArray[0];	
		//loop through each horizontal line
		foreach ($horizGridArray as $value) {
			$yValue = round($this->x_axis_y1 - ($value * $this->unit_scale) + $adjustment);
			if ($this->bool_grid) {
				//imageline($this->image, $this->y_axis_x1, $yValue, $this->x_axis_x2 , $yValue, $this->grid_color);
				$this->horiz_grid_lines[] = array('x1' => $this->y_axis_x1, 'y1' => $yValue, 
					'x2' => $this->x_axis_x2, 'y2' => $yValue, 'color' => $this->grid_color);
			}
			//display value on y axis if desired using calc'd grid values
			if ($this->bool_y_axis_values) {
				$adjustedYValue = $yValue - ($this->text_height / 2);
				$adjustedXValue = $this->y_axis_x1 - ((strlen($value) + $this->data_additional_length) * $this->text_width) - $this->axis_value_padding;
				//add currency sign, formatting etc
				if ($this->data_format_array) {
					$value = $this->applyDataFormats($value);
				}
				if ($this->data_currency) {
					$value = $this->applyDataCurrency($value);
				}
				//imagestring($this->image, 2, $adjustedXValue, $adjustedYValue, $value, $this->y_axis_text_color);
				$this->horiz_grid_values[] = array('size' => 2, 'x' => $adjustedXValue, 'y' => $adjustedYValue,
					'value' => $value, 'color' => $this->y_axis_text_color);
			}
		}
		if (!$this->bool_all_positive && !$this->bool_user_data_range) {
			//reset with better value based on grid min value calculations, not data min
			$this->y_axis_y1 = $this->x_axis_y1 - ($horizGridArray[0] * $this->unit_scale);
		}
		//reset with better value based on grid value calculations, not data min
		$this->y_axis_y2 = $yValue;
	}
	function calculateGridVert() {
		//determine vertical grid lines
		$vertGridArray = array();
		$vertGrids = $this->data_count + 1;
		$interval = $this->bar_width + $this->space_width;
		//assemble vert gridline array
		for ($i = 1; $i < $vertGrids; $i++) {
			$vertGridArray[] = $this->y_axis_x1 + ($interval * $i);
		}
		
		//loop through each vertical line
		if ($this->bool_grid) {
			$xValue = $this->y_axis_y1;
			foreach ($vertGridArray as $value) {
				//imageline($this->image, $value, $this->y_axis_y2, $value, $xValue , $this->grid_color);
				$this->vert_grid_lines[] = array('x1' => $value, 'y1' => $this->y_axis_y2, 
					'x2' => $value, 'y2' => $xValue, 'color' => $this->grid_color);
			}
		}
	}
	function imagelinedashed(&$image_handle, $x_axis_x1, $yLocation, $x_axis_x2 , $yLocation, $color) {
		$step  = 3;
		for ($i = $x_axis_x1; $i < $x_axis_x2 -1; $i += ($step*2)) {
			imageline($this->image, $i, $yLocation,  $i + $step - 1, $yLocation, $color);
		}
	}
	function generateGrids() {
		//loop through and display values
		foreach ($this->horiz_grid_lines as $line) {
			imageline($this->image, $line['x1'], $line['y1'], $line['x2'], $line['y2'] , $line['color']);
		}
		foreach ($this->vert_grid_lines as $line) {
			imageline($this->image, $line['x1'], $line['y1'], $line['x2'], $line['y2'] , $line['color']);
		}
		foreach ($this->horiz_grid_values as $value) {
			imagestring($this->image, $value['size'], $value['x'], $value['y'], $value['value'], $value['color']);
		}
		//not implemented in the base library, but used in extensions
		foreach ($this->vert_grid_values as $value) {
			imagestring($this->image, $value['size'], $value['x'], $value['y'], $value['value'], $value['color']);
		}
	}
	function generateGoalLines($adjustment = 0) {
		//draw goal lines if present (after grid) - doesn't get executed if array empty
		foreach ($this->goal_line_array as $goal_line_data) {
		    $yLocation = $goal_line_data['yValue'];
		    $style = $goal_line_data['style'];
		    $color = $goal_line_data['color'] ? $goal_line_data['color'] : $this->goal_line_color;
			$yLocation = round(($this->x_axis_y1 - ($yLocation * $this->unit_scale) + $adjustment));

			if ($style == 'dashed') {
				$this->imagelinedashed($this->image, $this->x_axis_x1, $yLocation, $this->x_axis_x2 , $yLocation, $color);
			}
			else {
				//a solid line is the default if a style condition is not matched
				imageline($this->image, $this->x_axis_x1, $yLocation, $this->x_axis_x2 , $yLocation, $color);
			}
		}
	}
	function generateDataPoints() {
		foreach ($this->data_point_array as $pointArray) {
			imagefilledellipse($this->image, $pointArray[0], $pointArray[1], $this->data_point_width, $this->data_point_width, $this->data_point_color);
		}		
	}
	function generateXAxis() {
		imageline($this->image, $this->x_axis_x1, $this->x_axis_y1, $this->x_axis_x2, $this->x_axis_y2, $this->x_axis_color);
	}
	function generateYAxis() {
		imageline($this->image, $this->y_axis_x1, $this->y_axis_y1, $this->y_axis_x2, $this->y_axis_y2, $this->y_axis_color);
	}
	function generateBackgound() {
		imagefilledrectangle($this->image, 0, 0, $this->width, $this->height, $this->background_color);
	}
	function generateTitle() {
		//spacing may have changed since earlier
		//use top margin or grid top y, whichever less
		$highestElement = ($this->top_margin < $this->y_axis_y2) ? $this->top_margin : $this->y_axis_y2;
		$textVertPos = ($highestElement / 2) - ($this->title_char_height / 2); //centered
		$titleLength = strlen($this->title_text);
		if ($this->bool_title_center) {
			$this->title_x = ($this->width / 2) - (($titleLength * $this->title_char_width) / 2);
			$this->title_y = $textVertPos;
		}
		else if ($this->bool_title_left) {
			$this->title_x = $this->y_axis_x1;
			$this->title_y = $textVertPos;
		}
		else if ($this->bool_title_right) {
			$this->title_x = $this->x_axis_x2 - ($titleLength * $this->title_char_width);
			$this->title_y = $textVertPos;
		}
		imagestring($this->image, 2, $this->title_x , $this->title_y , $this->title_text,  $this->title_color);
	}
	function calcTopMargin() {
		if ($this->bool_title) {
			//include space for title, approx margin + 3*title height
			$this->top_margin = ($this->height * ($this->x_axis_default_percent / 100)) + $this->title_char_height;
		}
		else {
			//just use default spacing
			$this->top_margin = $this->height * ($this->x_axis_default_percent / 100);
		}	
	}
	function calcRightMargin() {
		//just use default spacing
		$this->right_margin = $this->width * ($this->y_axis_default_percent / 100);
	}
	function calcCoords() {
		//calculate axis points, also used for other calculations
		$this->x_axis_x1 = $this->y_axis_margin;
		$this->x_axis_y1 = $this->height - $this->x_axis_margin;
		$this->x_axis_x2 = $this->width - $this->right_margin;
		$this->x_axis_y2 = $this->height - $this->x_axis_margin;
		$this->y_axis_x1 = $this->y_axis_margin;
		$this->y_axis_y1 = $this->height - $this->x_axis_margin;
		$this->y_axis_x2 = $this->y_axis_margin;
		$this->y_axis_y2 = $this->top_margin;
	}
	
	function determineAxisMarkerScale($max, $min, $axis = 'y') {
		switch ($axis) {
			case 'y' : $space = $this->height; break;
			case 'x' : $space = $this->width; break;
		}
	
		//for calclation, take range or max-0
		if ($this->bool_user_data_range) {
			$range = abs($max - $min);
		}
		else {
			$range = (abs($max-$min) > abs($max - 0)) ? abs($max - $min) : abs($max - 0);
		}
		//handle all zero data
		if ($range == 0) {
			$range = 10;
		}
		//multiply up to over 100, to better figure interval
		$count = 0;
		while (abs($range) < 100) {
			$range *= 10;
			$count++;
		}
		//divide into intervals based on height / preset constant - after rounding will be approx
		$divisor = round($space / $this->range_divisor_factor);
		$divided = round($range / $divisor);
		$result = $this->roundUpOneExtraDigit($divided);
		//if rounded up w/ extra digit is more than 200% of divided value,
		//round up to next sig number with same num of digits
		if ($result / $divided >= 2) {
			$result = $this->roundUpSameDigits($divided);
		}
		//divide back down, if needed
		for ($i = 0; $i < $count; $i++) {
			$result /= 10;
		}
		return $result;	
	}
	
	function roundUpSameDigits($num) {           
		$len = strlen($num);  
		if (round($num, -1 * ($len - 1)) == $num) {
			//we already have a sig number
			return $num;
		}
		else {
			$firstDig = substr($num, 0,1);
			$secondDig = substr($num, 1,1);
			$rest = substr($num, 2);
			$secondDig = 5;
			$altered = $firstDig.$secondDig.$rest;
			//after reassembly, round up to next sig number, same # of digits
			return round((int)$altered, -1 * ($len - 1));
		}
	}
	function roundUpOneExtraDigit($num) {                     
		$len = strlen($num);  
		$firstDig = substr($num, 0, 1);
		$rest = substr($num, 1);
		$firstDig = 5;
		$altered = $firstDig . $rest;
		//after reassembly, round up to next sig number, one extra # of digits
		return round((int)$altered, -1 * ($len)); 
	}
	function displayErrors() {
		if (count($this->error) > 0) {
			$lineHeight = 12;
			$errorColor = imagecolorallocate($this->image, 0, 0, 0);
			$errorBackColor = imagecolorallocate($this->image, 255, 204, 0);
			imagefilledrectangle($this->image, 0, 0, $this->width - 1, 2 * $lineHeight,  $errorBackColor);
			imagestring($this->image, 3, 2, 0, "!!----- PHPGraphLib Error -----!!",  $errorColor);
			foreach($this->error as $key => $errorText) {
				imagefilledrectangle($this->image, 0, ($key * $lineHeight) + $lineHeight, $this->width - 1, ($key * $lineHeight) + 2 * $lineHeight,  $errorBackColor);	
				imagestring($this->image, 2, 2, ($key * $lineHeight) + $lineHeight, "[". ($key + 1) . "] ". $errorText,  $errorColor);	
			}
			$errorOutlineColor = imagecolorallocate($this->image, 255, 0, 0);
			imagerectangle($this->image, 0, 0, $this->width-1,($key * $lineHeight) + 2 * $lineHeight,  $errorOutlineColor);		
		}
	}
	function addData($data, $data2 = '', $data3 = '', $data4 = '', $data5 = '') {
		if (is_array($data)){ $this->data_array[]=$data; }
		if (is_array($data2)){ $this->data_array[]=$data2; }
		if (is_array($data3)){ $this->data_array[]=$data3; }
		if (is_array($data4)){ $this->data_array[]=$data4; }
		if (is_array($data5)){ $this->data_array[]=$data5; }
		//assess data
		$min = $this->data_max_allowable;
		$max = $this->data_min_allowable;
		$this->data_count = 0;
		//get rid of bad data, find max, min
		foreach ($this->data_array as $data_set_num => $data_set) {
			foreach ($data_set as $key => $item) {
				if (!is_numeric($item)) {
					unset($this->data_array[$data_set_num][$key]);
				}
				else {
					if ($item < $min){ $min = $item; }
					if ($item > $max){ $max = $item; }
				}
			}
			//find the count of the dataset with the most data points
			$count = count($this->data_array[$data_set_num]);
			$count > $this->data_count ? ($this->data_count = $count) : NULL; 
		}
		//number of valid data sets
		$this->data_set_count = count($this->data_array);
		if ($this->data_set_count == 0) {
			$this->error[] = "No valid datasets added in adddata() function.";
		}
		else {
			$this->calcMinMax($min, $max);
		}
	}
	function calcMinMax($min, $max) {
		$this->bool_data = true;
		//min and max for all datasets
		$this->data_min = $min;
		$this->data_max = $max;
		if ($this->data_min >= 0) {
			$this->bool_all_positive = true;
		}
		else if ($this->data_max<=0) {
			$this->bool_all_negative=true;
		}
		//setup fake max and min for all zero data
		if ($this->data_min >= 0 && $this->data_max == 0 ) {
			$this->data_min = 0;
			$this->data_max = 10;
			$this->all_zero_data = true;
		} 
	}
	function setupXAxis($percent = '', $color = '') {
		if ($percent === false) {
			$this->bool_x_axis = false;
		}
		else {
			$this->bool_x_axis = true;
		}
		$this->bool_x_axis_setup = true;
		if (!empty($color) && $arr = $this->returnColorArray($color)) {
			$this->x_axis_color = imagecolorallocate($this->image, $arr[0], $arr[1], $arr[2]);
		}
		if (is_numeric($percent) && $percent>0) { 
			$percent = $percent / 100;
			$this->x_axis_margin = round($this->height * $percent);
		}
		else {
			$percent = $this->x_axis_default_percent / 100;
			$this->x_axis_margin = round($this->height * $percent);
		}	
	}
	function setupYAxis($percent = '', $color = '') {
		if ($percent === false) {
			$this->bool_y_axis = false;
		}
		else {
			$this->bool_y_axis = true;
		}
		$this->bool_y_axis_setup = true;
		if (!empty($color) && $arr = $this->returnColorArray($color)) {
			$this->y_axis_color = imagecolorallocate($this->image, $arr[0], $arr[1], $arr[2]);
		}
		if (is_numeric($percent) && $percent>0) { 
			$this->y_axis_margin = round($this->width * ($percent / 100));
		}
		else {
			$percent = $this->y_axis_default_percent / 100;
			$this->y_axis_margin = round($this->width * $percent);
		}
	}
	function setRange($min, $max) {
		//because of deprecated use of this function as($max, $min)
		if ($min > $max) {
			$this->data_range_max = $min;
			$this->data_range_min = $max;
		}
		else {
			$this->data_range_max = $max;
			$this->data_range_min = $min;
		}
		$this->bool_user_data_range = true;
	}
	function setTitle($title) {
		if (!empty($title)) {
			$this->title_text = $title;
			$this->bool_title = true;
		}
		else{ $this->error[] = "String arg for setTitle() not specified properly."; }	
	}
	function setTitleLocation($location) {
		$this->bool_title_left = false;
		$this->bool_title_right = false;
		$this->bool_title_center = false;
		switch (strtolower($location)) {
			case 'left': $this->bool_title_left = true; break;
			case 'right': $this->bool_title_right = true; break;
			case 'center': $this->bool_title_center = true; break;
			default: $this->error[] = "String arg for setTitleLocation() not specified properly.";
		}	
	}
	function setBars($bool) {
		if (is_bool($bool)) { $this->bool_bars = $bool;}
		else { $this->error[] = "Boolean arg for setBars() not specified properly."; }
	}
	function setGrid($bool) {
		if (is_bool($bool)) { $this->bool_grid = $bool;}
		else { $this->error[] = "Boolean arg for setGrid() not specified properly."; }
	}
	function setXValues($bool) {
		if (is_bool($bool)) { $this->bool_x_axis_values = $bool; }
		else { $this->error[] = "Boolean arg for setXValues() not specified properly."; }
	}
	function setYValues($bool) {
		if (is_bool($bool)) { $this->bool_y_axis_values = $bool; }
		else { $this->error[] = "Boolean arg for setYValues() not specified properly."; }
	}
	function setXValuesHorizontal($bool) {
		if (is_bool($bool)) { 
			($bool) ? $this->bool_x_axis_values_vert = false : $this->bool_x_axis_values_vert = true;
		}
		else{ $this->error[] = "Boolean arg for setXValuesHorizontal() not specified properly."; }
	}
	function setXValuesVertical($bool) {
		if (is_bool($bool)) { $this->bool_x_axis_values_vert = $bool; }
		else { $this->error[] = "Boolean arg for setXValuesVertical() not specified properly."; }
	}
	function setBarOutline($bool) {
		if (is_bool($bool)) { $this->bool_bar_outline = $bool; }
		else { $this->error[] = "Boolean arg for setBarOutline() not specified properly."; }
	}
	function setDataPoints($bool) {
		if (is_bool($bool)) { $this->bool_data_points = $bool; }
		else { $this->error[] = "Boolean arg for setDataPoints() not specified properly."; }
	}
	function setDataPointSize($size) {
		if (is_numeric($size)) { $this->data_point_width = $size; }
		else { $this->error[] = "Data point size in setDataPointSize() not specified properly."; }
	}
	function setDataValues($bool) {
		if (is_bool($bool)) { $this->bool_data_values = $bool; }
		else{ $this->error[] = "Boolean arg for setDataValues() not specified properly."; }
	}
	function setDataCurrency($currency_type = 'dollar') {
		switch (strtolower($currency_type)) {
			case 'dollar': $this->data_currency = '$'; break;
			case 'yen': $this->data_currency = '¥'; break;
			case 'pound': $this->data_currency = '£'; break;
			case 'lira': $this->data_currency = '£'; break;
			/* Euro doesn't display properly...
			case 'euro': $this->data_currency = '€'; break; */
			/* Franc doesn't display properly
			case 'franc': $this->data_currency = '?'; break; */
			default: $this->data_currency = $currency_type; break;
		}
		$this->data_additional_length += strlen($this->data_currency);
	}
	function applyDataCurrency($input) {
		return $this->data_currency . $input;
	}
	function setDataFormat($format) {
		//setup structure for future additional data formats - specify callback functions
		switch ($format) {
			case 'comma': 
				$this->data_format_array[] = 'formatDataAsComma';
				$this->data_additional_length += floor(strlen($this->data_max) / 3);
				break;
			case 'percent': 
				$this->data_format_array[] = 'formatDataAsPercent'; 
				$this->data_additional_length++; 
				break;
			case 'degrees': 
				$this->data_format_array[] = 'formatDataAsDegrees'; 
				$this->data_additional_length++; 
				break;
			default: 
				$this->data_format_array[] = 'formatDataAsGeneric'; 
				$this->data_format_generic = $format; 
				$this->data_additional_length += strlen($format);
				break;
		}
	}
	function applyDataFormats($input) {
		//comma formatting must be done first
		if ($pos = array_search('formatDataAsComma', $this->data_format_array)) {
			unset($this->data_format_array[$pos]);
			array_unshift($this->data_format_array, 'formatDataAsComma');
		}
		//loop through each formatting function
		foreach ($this->data_format_array as $format_type_callback) {
			eval('$input=$this->' . $format_type_callback . '($input);');
		}
		return $input;
	}
	function formatDataAsComma($input) {
		//check for negative sign
		$sign_part = '';
		if (substr($input, 0, 1) == '-') {
			$input = substr($input, 1);
			$sign_part = '-';
		}
		//handle decimals
		$decimal_part = '';
		if (($pos = strpos($input, '.')) !== false) {
			$decimal_part = substr($input, $pos);
			$input = substr($input, 0, $pos);
		}
		//turn data into format 12,234...
		$parts = '';
		while (strlen($input)>3) {
			$parts = ',' . substr($input, -3) . $parts;	
			$input = substr($input, 0, strlen($input) - 3);
		}
		$input = $sign_part . $currency_part . $input . $parts . $decimal_part;
		return $input;
	}
	function formatDataAsPercent($input) {
		return $input . '%';
	}
	function formatDataAsDegrees($input) {
		return $input . '°';
	}
	function formatDataAsGeneric($input) {
		return $input . $this->data_format_generic;
	}
	function setLine($bool) {
		if (is_bool($bool)) { $this->bool_line = $bool; }
		else { $this->error[] = "Boolean arg for setLine() not specified properly."; }
	}
	function setGoalLine($yValue, $color = NULL, $style = 'solid') {
		if (is_numeric($yValue)) {
		
		    if ($color) {
				$this->setGenericColor($color, '$this->goal_line_custom_color', "Goal line color not specified properly.");	
				$color = $this->goal_line_custom_color;
			}
		
			$this->goal_line_array[] = array('yValue' => $yValue, 'color' => $color, 'style' => $style);
		}
		else {
			$this->error[] = "Goal line Y axis value not specified properly.";
		}
	}
	function allocateColors() {
		$this->background_color = imagecolorallocate($this->image, 255, 255, 255);
		$this->grid_color = imagecolorallocate($this->image, 220, 220, 220);
		$this->bar_color = imagecolorallocate($this->image, 200, 200, 200);
		$this->line_color_default = imagecolorallocate($this->image, 100, 100, 100);
		$this->x_axis_text_color = $this->line_color_default;
		$this->y_axis_text_color = $this->line_color_default;
		$this->data_value_color = $this->line_color_default;
		$this->title_color = imagecolorallocate($this->image, 0, 0, 0);
		$this->outline_color = $this->title_color;
		$this->data_point_color = $this->title_color;
		$this->x_axis_color = $this->title_color;
		$this->y_axis_color = $this->title_color;
		$this->goal_line_color = $this->title_color;
		//New Legend Colors
		$this->legend_outline_color = $this->grid_color;
		$this->legend_color = $this->background_color;
		$this->legend_text_color = $this->line_color_default;
		$this->legend_swatch_outline_color = $this->line_color_default;
	}
	function returnColorArray($color) {
		//check to see if numeric color passed through in form '128,128,128'
		if (strpos($color,',') !== false) {
			return explode(',', $color);
		}
		//check to see if in hex format
		else if (substr($color, 0, 1) == '#') {	
			if (strlen($color) == 7) {
				$hex1 = hexdec(substr($color, 1, 2));
				$hex2 = hexdec(substr($color, 3, 2));
				$hex3 = hexdec(substr($color, 5, 2));
				return array($hex1, $hex2, $hex3);
			}
			else if (strlen($color) == 4) {
				$hex1 = hexdec(substr($color, 1, 1) . substr($color, 1, 1));
				$hex2 = hexdec(substr($color, 2, 1) . substr($color, 2, 1));
				$hex3 = hexdec(substr($color, 3, 1) . substr($color, 3, 1));
				return array($hex1, $hex2, $hex3);
			}			
		}
		switch (strtolower($color)) {
			//NAMED COLORS BASED ON W3C's RECOMMENDED HTML COLORS
			case 'black':  return array(0,0,0); break;
			case 'silver': return array(192,192,192); break;
			case 'gray':   return array(128,128,128); break;
			case 'white':  return array(255,255,255); break;
			case 'maroon': return array(128,0,0); break;
			case 'red':    return array(255,0,0); break;
			case 'purple': return array(128,0,128); break;
			case 'fuscia': return array(255,0,255); break;
			case 'green':  return array(0,128,0); break;
			case 'lime':   return array(0,255,0); break;
			case 'olive':  return array(128,128,0); break;
			case 'yellow': return array(255,255,0); break;
			case 'navy':   return array(0,0,128); break;	
			case 'blue':   return array(0,0,255); break;
			case 'teal':   return array(0,128,128); break;
			case 'aqua':   return array(0,255,255); break;	
		}
		$this->error[] = "Color name \"$color\" not recogized.";
		return false;
	}
	function allocateGradientColors($color1R, $color1G, $color1B, $rScale, $gScale, $bScale, $num, $data_set_num) {
		//caluclate the colors used in our gradient and store them in array
		$this->gradient_color_array[$data_set_num] = array();
		for ($i = 0; $i <= $num + 1; $i++) {
			$this->gradient_color_array[$data_set_num][$i] = imagecolorallocate($this->image, $color1R - ($rScale * $i), $color1G - ($gScale * $i), $color1B - ($bScale * $i));
		}
		$this->bool_gradient_colors_found[$data_set_num] = true;
	}
	function setGenericColor($inputColor, $var, $errorMsg) {
		//can be used for most color setting options
		if (!empty($inputColor) && ($arr = $this->returnColorArray($inputColor))) {
			eval($var . ' = imagecolorallocate($this->image, $arr[0], $arr[1], $arr[2]);');
			return true;	
		}
		else {
			$this->error[] = $errorMsg;
			return false;
		}
	}
	function setBackgroundColor($color) {
		if ($this->setGenericColor($color, '$this->background_color', "Background color not specified properly.")) {
			$this->bool_background = true;
		}
	}
	function setTitleColor($color) {
		$this->setGenericColor($color, '$this->title_color', "Title color not specified properly.");
	}
	function setTextColor($color) {
		$this->setGenericColor($color, '$this->x_axis_text_color', "X axis text color not specified properly.");
		$this->setGenericColor($color, '$this->y_axis_text_color', "Y axis Text color not specified properly.");
	}
	function setXAxisTextColor($color) {
		$this->setGenericColor($color, '$this->x_axis_text_color', "X axis text color not specified properly.");
	}
	function setYAxisTextColor($color) {
		$this->setGenericColor($color, '$this->y_axis_text_color', "Y axis Text color not specified properly.");
	}
	function setBarColor($color, $color2 = '', $color3 = '', $color4 = '', $color5 = '') {
		$this->setGenericColor($color, '$this->multi_bar_colors[]', "Bar color not specified properly.");
		if (!empty($color2)) {
			$this->setGenericColor($color2, '$this->multi_bar_colors[]', "Bar color 2 not specified properly.");
		}
		if (!empty($color3)) {
			$this->setGenericColor($color3, '$this->multi_bar_colors[]', "Bar color 3 not specified properly.");
		}
		if (!empty($color4)) {
			$this->setGenericColor($color4, '$this->multi_bar_colors[]', "Bar color 4 not specified properly.");
		}
		if (!empty($color5)) {
			$this->setGenericColor($color5, '$this->multi_bar_colors[]', "Bar color 5 not specified properly.");
		}	
	}
	function setGridColor($color) {
		$this->setGenericColor($color, '$this->grid_color', "Grid color not specified properly.");
	}
	function setBarOutlineColor($color) {
		$this->setGenericColor($color, '$this->outline_color', "Bar outline color not specified properly.");
	}
	function setDataPointColor($color) {
		$this->setGenericColor($color, '$this->data_point_color', "Data point color not specified properly.");
	}
	function setDataValueColor($color) {
		$this->setGenericColor($color, '$this->data_value_color', "Data value color not specified properly.");	
	}
	function setLineColor($color, $color2 = '', $color3 = '', $color4 = '', $color5 = '') {
		$this->setGenericColor($color, '$this->line_color[]', "Line color not specified properly.");
		if (!empty($color2)) {
			$this->setGenericColor($color2, '$this->line_color[]', "Line color 2 not specified properly.");
		}
		if (!empty($color3)) {
			$this->setGenericColor($color3, '$this->line_color[]', "Line color 3 not specified properly.");	
		}
		if (!empty($color4)) {
			$this->setGenericColor($color4, '$this->line_color[]', "Line color 4 not specified properly.");	
		}
		if (!empty($color5)) {
			$this->setGenericColor($color5, '$this->line_color[]', "Line color 5 not specified properly.");	
		}
	}
	/* @deprecated - setGoalLineColor() replaced with 2nd parameter of setGoalLine() */
	function setGoalLineColor($color) {
		$this->setGenericColor($color, '$this->goal_line_color', "Goal line color not specified properly.");
	}
	function setGradient($color1, $color2, $color3='', $color4='', $color5='', $color6='', $color7='', $color8='', $color9='', $color10='') {
		if (!empty($color1) && !empty($color2) && ($arr1 = $this->returnColorArray($color1)) && ($arr2 = $this->returnColorArray($color2))) {
			$this->bool_gradient=true;
			$this->multi_gradient_colors_1[] = $arr1;
			$this->multi_gradient_colors_2[] = $arr2;
		}
		else {
			$this->error[] = "Gradient color(s) not specified properly.";
		}
		//Optional gradients
		if (!empty($color3) && !empty($color4) && ($arr1=$this->returnColorArray($color3)) && ($arr2 = $this->returnColorArray($color4))) {
			$this->bool_gradient=true;
			$this->multi_gradient_colors_1[]=$arr1;
			$this->multi_gradient_colors_2[]=$arr2;
		}
		if (!empty($color5) && !empty($color6) && ($arr1 = $this->returnColorArray($color5)) && ($arr2 = $this->returnColorArray($color6))) {
			$this->bool_gradient = true;
			$this->multi_gradient_colors_1[] = $arr1;
			$this->multi_gradient_colors_2[] = $arr2;
		}
		if (!empty($color7) && !empty($color8) && ($arr1 = $this->returnColorArray($color7)) && ($arr2 = $this->returnColorArray($color8))) {
			$this->bool_gradient = true;
			$this->multi_gradient_colors_1[] = $arr1;
			$this->multi_gradient_colors_2[] = $arr2;
		}
		if (!empty($color9) && !empty($color10) && ($arr1 = $this->returnColorArray($color9)) && ($arr2 = $this->returnColorArray($color10))) {
			$this->bool_gradient = true;
			$this->multi_gradient_colors_1[] = $arr1;
			$this->multi_gradient_colors_2[] = $arr2;
		}
	}
	//Legend Related Functions
	function setLegend($bool) {
		if (is_bool($bool)) { $this->bool_legend = $bool;}
		else { $this->error[] = "Boolean arg for setLegend() not specified properly."; }
	}
	function setLegendColor($color) {
		$this->setGenericColor($color, '$this->legend_color', "Legend color not specified properly.");
	}
	function setLegendTextColor($color) {
		$this->setGenericColor($color, '$this->legend_text_color', "Legend text color not specified properly.");
	}
	function setLegendOutlineColor($color) {
		$this->setGenericColor($color, '$this->legend_outline_color', "Legend outline color not specified properly.");
	}
	function setSwatchOutlineColor($color) {
		$this->setGenericColor($color, '$this->legend_swatch_outline_color', "Swatch outline color not specified properly.");
	}
	function setLegendTitle($title, $title2 = '', $title3 = '', $title4 = '', $title5 = '') {
		if (!empty($title)) { 		
			$len = strlen($title);
			if ($len > $this->legend_max_chars){ 
				$title = substr($title, 0, $this->legend_max_chars); 
				$this->legend_total_chars[] = $this->legend_max_chars;
			}
			else {$this->legend_total_chars[] = $len;}
			$this->legend_titles[] = $title; 
		}
		else {$this->error[] = "String arg 1 for setLegendTitles() not specified properly."; }
		if (!empty($title2)) { 
			$len = strlen($title2);
			if ($len > $this->legend_max_chars) { 
				$title2 = substr($title2, 0, $this->legend_max_chars); 
				$this->legend_total_chars[] = $this->legend_max_chars;
			}
			else {$this->legend_total_chars[] = $len;}
			$this->legend_titles[] = $title2; 
		}
		if (!empty($title3)) { 
			$len = strlen($title3);
			if ($len > $this->legend_max_chars){ 
				$title3 = substr($title3, 0, $this->legend_max_chars); 
				$this->legend_total_chars[] = $this->legend_max_chars;
			}
			else {$this->legend_total_chars[] = $len;}
			$this->legend_titles[] = $title3; 
		}
		if (!empty($title4)) { 
			$len = strlen($title4);
			if ($len > $this->legend_max_chars){ 
				$title4 = substr($title4, 0, $this->legend_max_chars); 
				$this->legend_total_chars[] = $this->legend_max_chars;
			}
			else {$this->legend_total_chars[] = $len;}
			$this->legend_titles[] = $title4; 
		}
		if (!empty($title5)) { 
			$len = strlen($title5);
			if ($len > $this->legend_max_chars){ 
				$title5 = substr($title5, 0, $this->legend_max_chars); 
				$this->legend_total_chars[] = $this->legend_max_chars;
			}
			else {$this->legend_total_chars[] = $len;}
			$this->legend_titles[] = $title5; 
		}
	}
	function generateLegend() {
		$swatchToTextOffset = ($this->legend_text_height - 6) / 2;
		$swatchSize = $this->legend_text_height - (2 * $swatchToTextOffset);
		//calc height / width based on # of data sets
		$this->legend_height = $this->legend_text_height + (2 * $this->legend_padding);
		$totalChars = 0;
		for ($i = 0; $i < $this->data_set_count; $i++) {
			//could have more titles than data sets - check for this
			if (isset($this->legend_total_chars[$i])){ $totalChars += $this->legend_total_chars[$i]; }
		}
		$this->legend_width = $totalChars * $this->legend_text_width + ($this->legend_padding * 2.2) + 
			($this->data_set_count * ($swatchSize + ($this->legend_padding * 2)));
		$this->legend_x = $this->x_axis_x2 - $this->legend_width;
		$highestElement = ($this->top_margin < $this->y_axis_y2) ? $this->top_margin : $this->y_axis_y2;
		$this->legend_y = ($highestElement / 2) - ($this->legend_height / 2); //centered
		//background
		imagefilledrectangle($this->image, $this->legend_x, $this->legend_y, $this->legend_x+$this->legend_width, 
			$this->legend_y + $this->legend_height, $this->legend_color);
		//border
		imagerectangle($this->image, $this->legend_x, $this->legend_y, $this->legend_x+$this->legend_width, 
			$this->legend_y+$this->legend_height, $this->legend_outline_color);
		$length_covered = 0;
		for($i = 0; $i < $this->data_set_count; $i++) {
			$data_label = '';
			if (isset($this->legend_titles[$i])) {
				$data_label = $this->legend_titles[$i];
			}
			$yValue = $this->legend_y + $this->legend_padding;
			$xValue = $this->legend_x + $this->legend_padding + ($length_covered * $this->legend_text_width) + ($i * 4 * $this->legend_padding);
			$length_covered += strlen($data_label);
			//draw color boxes
			if ($this->bool_bars) {
				if ($this->bool_gradient) {
					$color = $this->gradient_color_array[$this->data_set_count - $i - 1][0];
				}
				else{
					$color = $this->multi_bar_colors[$this->data_set_count - $i - 1];
				}
			}
			else if ($this->bool_line&&!$this->bool_bars)
			{
				$color = $this->line_color[$this->data_set_count - $i - 1];
			}
			imagefilledrectangle($this->image, $xValue, $yValue+$swatchToTextOffset, $xValue + $swatchSize, $yValue + $swatchToTextOffset + $swatchSize, $color);
			imagerectangle($this->image, $xValue, $yValue + $swatchToTextOffset, $xValue + $swatchSize, $yValue + $swatchToTextOffset + $swatchSize, $this->legend_swatch_outline_color);	
			imagestring($this->image, 2, $xValue + (2 * $this->legend_padding + 2), $yValue, $data_label, $this->legend_text_color);
		}
	}
}
?>