lib/graphlib.php

   1 <?php
   2
   3 /**
   4  * Graph Class. PHP Class to draw line, point, bar, and area graphs, including numeric x-axis and double y-axis.
   5  * Version: 1.6.3
   6  * Copyright (C) 2000  Herman Veluwenkamp
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  *
  22  * Copy of GNU Lesser General Public License at: http://www.gnu.org/copyleft/lesser.txt
  23  * Contact author at: hermanV@mindless.com
  24  *
  25  * @package    core
  26  * @subpackage lib
  27  */
  28
  29 defined('MOODLE_INTERNAL') || die();
  30
  31 /* This file contains modifications by Martin Dougiamas
  32  * as part of Moodle (http://moodle.com).  Modified lines
  33  * are marked with "Moodle".
  34  */
  35
  36 /**
  37  * @package moodlecore
  38  */
  39 class graph {
  40   var $image;
  41   var $debug             =   FALSE;        // be careful!!
  42   var $calculated        =   array();      // array of computed values for chart
  43   var $parameter         =   array(        // input parameters
  44     'width'              =>  320,          // default width of image
  45     'height'             =>  240,          // default height of image
  46     'file_name'          => 'none',        // name of file for file to be saved as.
  47                                            //  NOTE: no suffix required. this is determined from output_format below.
  48     'output_format'      => 'PNG',         // image output format. 'GIF', 'PNG', 'JPEG'. default 'PNG'.
  49
  50     'seconds_to_live'    =>  0,            // expiry time in seconds (for HTTP header)
  51     'hours_to_live'      =>  0,            // expiry time in hours (for HTTP header)
  52     'path_to_fonts'      => 'fonts/',      // path to fonts folder. don't forget *trailing* slash!!
  53                                            //   for WINDOZE this may need to be the full path, not relative.
  54
  55     'title'              => 'Graph Title', // text for graph title
  56     'title_font'         => 'default.ttf',   // title text font. don't forget to set 'path_to_fonts' above.
  57     'title_size'         =>  16,           // title text point size
  58     'title_colour'       => 'black',       // colour for title text
  59
  60     'x_label'            => '',            // if this is set then this text is printed on bottom axis of graph.
  61     'y_label_left'       => '',            // if this is set then this text is printed on left axis of graph.
  62     'y_label_right'      => '',            // if this is set then this text is printed on right axis of graph.
  63
  64     'label_size'         =>  8,           // label text point size
  65     'label_font'         => 'default.ttf', // label text font. don't forget to set 'path_to_fonts' above.
  66     'label_colour'       => 'gray33',      // label text colour
  67     'y_label_angle'      =>  90,           // rotation of y axis label
  68
  69     'x_label_angle'      =>  90,            // rotation of y axis label
  70
  71     'outer_padding'      =>  5,            // padding around outer text. i.e. title, y label, and x label.
  72     'inner_padding'      =>  0,            // padding beteen axis text and graph.
  73     'x_inner_padding'      =>  5,            // padding beteen axis text and graph.
  74     'y_inner_padding'      =>  6,            // padding beteen axis text and graph.
  75     'outer_border'       => 'none',        // colour of border aound image, or 'none'.
  76     'inner_border'       => 'black',       // colour of border around actual graph, or 'none'.
  77     'inner_border_type'  => 'box',         // 'box' for all four sides, 'axis' for x/y axis only,
  78                                            // 'y' or 'y-left' for y axis only, 'y-right' for right y axis only,
  79                                            // 'x' for x axis only, 'u' for both left and right y axis and x axis.
  80     'outer_background'   => 'none',        // background colour of entire image.
  81     'inner_background'   => 'none',        // background colour of plot area.
  82
  83     'y_min_left'         =>  0,            // this will be reset to minimum value if there is a value lower than this.
  84     'y_max_left'         =>  0,            // this will be reset to maximum value if there is a value higher than this.
  85     'y_min_right'        =>  0,            // this will be reset to minimum value if there is a value lower than this.
  86     'y_max_right'        =>  0,            // this will be reset to maximum value if there is a value higher than this.
  87     'x_min'              =>  0,            // only used if x axis is numeric.
  88     'x_max'              =>  0,            // only used if x axis is numeric.
  89
  90     'y_resolution_left'  =>  1,            // scaling for rounding of y axis max value.
  91                                            // if max y value is 8645 then
  92                                            // if y_resolution is 0, then y_max becomes 9000.
  93                                            // if y_resolution is 1, then y_max becomes 8700.
  94                                            // if y_resolution is 2, then y_max becomes 8650.
  95                                            // if y_resolution is 3, then y_max becomes 8645.
  96                                            // get it?
  97     'y_decimal_left'     =>  0,            // number of decimal places for y_axis text.
  98     'y_resolution_right' =>  2,            // ... same for right hand side
  99     'y_decimal_right'    =>  0,            // ... same for right hand side
 100     'x_resolution'       =>  2,            // only used if x axis is numeric.
 101     'x_decimal'          =>  0,            // only used if x axis is numeric.
 102
 103     'point_size'         =>  4,            // default point size. use even number for diamond or triangle to get nice look.
 104     'brush_size'         =>  4,            // default brush size for brush line.
 105     'brush_type'         => 'circle',      // type of brush to use to draw line. choose from the following
 106                                            //   'circle', 'square', 'horizontal', 'vertical', 'slash', 'backslash'
 107     'bar_size'           =>  0.8,          // size of bar to draw. <1 bars won't touch
 108                                            //   1 is full width - i.e. bars will touch.
 109                                            //   >1 means bars will overlap.
 110     'bar_spacing'        =>  10,           // space in pixels between group of bars for each x value.
 111     'shadow_offset'      =>  3,            // draw shadow at this offset, unless overidden by data parameter.
 112     'shadow'             => 'grayCC',      // 'none' or colour of shadow.
 113     'shadow_below_axis'  => true,         // whether to draw shadows of bars and areas below the x/zero axis.
 114
 115
 116     'x_axis_gridlines'   => 'auto',        // if set to a number then x axis is treated as numeric.
 117     'y_axis_gridlines'   =>  6,            // number of gridlines on y axis.
 118     'zero_axis'          => 'none',        // colour to draw zero-axis, or 'none'.
 119
 120
 121     'axis_font'          => 'default.ttf', // axis text font. don't forget to set 'path_to_fonts' above.
 122     'axis_size'          =>  8,            // axis text font size in points
 123     'axis_colour'        => 'gray33',      // colour of axis text.
 124     'y_axis_angle'       =>  0,            // rotation of axis text.
 125     'x_axis_angle'       =>  0,            // rotation of axis text.
 126
 127     'y_axis_text_left'   =>  1,            // whether to print left hand y axis text. if 0 no text, if 1 all ticks have text,
 128     'x_axis_text'        =>  1,            //   if 4 then print every 4th tick and text, etc...
 129     'y_axis_text_right'  =>  0,            // behaviour same as above for right hand y axis.
 130
 131     'x_offset'           =>  0.5,          // x axis tick offset from y axis as fraction of tick spacing.
 132     'y_ticks_colour'     => 'black',       // colour to draw y ticks, or 'none'
 133     'x_ticks_colour'     => 'black',       // colour to draw x ticks, or 'none'
 134     'y_grid'             => 'line',        // grid lines. set to 'line' or 'dash'...
 135     'x_grid'             => 'line',        //   or if set to 'none' print nothing.
 136     'grid_colour'        => 'grayEE',      // default grid colour.
 137     'tick_length'        =>  4,            // length of ticks in pixels. can be negative. i.e. outside data drawing area.
 138
 139     'legend'             => 'none',        // default. no legend.
 140                                           // otherwise: 'top-left', 'top-right', 'bottom-left', 'bottom-right',
 141                                           //   'outside-top', 'outside-bottom', 'outside-left', or 'outside-right'.
 142     'legend_offset'      =>  10,           // offset in pixels from graph or outside border.
 143     'legend_padding'     =>  5,            // padding around legend text.
 144     'legend_font'        => 'default.ttf',   // legend text font. don't forget to set 'path_to_fonts' above.
 145     'legend_size'        =>  8,            // legend text point size.
 146     'legend_colour'      => 'black',       // legend text colour.
 147     'legend_border'      => 'none',        // legend border colour, or 'none'.
 148
 149     'decimal_point'      => '.',           // symbol for decimal separation  '.' or ',' *european support.
 150     'thousand_sep'       => ',',           // symbol for thousand separation ',' or ''
 151
 152   );
 153   var $y_tick_labels     =   null;         // array of text values for y-axis tick labels
 154   var $offset_relation   =   null;         // array of offsets for different sets of data
 155
 156
 157     // init all text - title, labels, and axis text.
 158     function init() {
 159
 160       /// Moodle mods:  overrides the font path and encodings
 161
 162       global $CFG;
 163
 164       /// A default.ttf is searched for in this order:
 165       ///      dataroot/lang/xx_local/fonts
 166       ///      dataroot/lang/xx/fonts
 167       ///      dirroot/lang/xx/fonts
 168       ///      dataroot/lang
 169       ///      lib/
 170
 171       $currlang = current_language();
 172       if (file_exists("$CFG->dataroot/lang/".$currlang."_local/fonts/default.ttf")) {
 173           $fontpath = "$CFG->dataroot/lang/".$currlang."_local/fonts/";
 174       } else if (file_exists("$CFG->dataroot/lang/$currlang/fonts/default.ttf")) {
 175           $fontpath = "$CFG->dataroot/lang/$currlang/fonts/";
 176       } else if (file_exists("$CFG->dirroot/lang/$currlang/fonts/default.ttf")) {
 177           $fontpath = "$CFG->dirroot/lang/$currlang/fonts/";
 178       } else if (file_exists("$CFG->dataroot/lang/default.ttf")) {
 179           $fontpath = "$CFG->dataroot/lang/";
 180       } else {
 181           $fontpath = "$CFG->libdir/";
 182       }
 183
 184       $this->parameter['path_to_fonts'] = $fontpath;
 185
 186       /// End Moodle mods
 187
 188
 189
 190       $this->calculated['outer_border'] = $this->calculated['boundary_box'];
 191
 192       // outer padding
 193       $this->calculated['boundary_box']['left']   += $this->parameter['outer_padding'];
 194       $this->calculated['boundary_box']['top']    += $this->parameter['outer_padding'];
 195       $this->calculated['boundary_box']['right']  -= $this->parameter['outer_padding'];
 196       $this->calculated['boundary_box']['bottom'] -= $this->parameter['outer_padding'];
 197
 198       $this->init_x_axis();
 199       $this->init_y_axis();
 200       $this->init_legend();
 201       $this->init_labels();
 202
 203       //  take into account tick lengths
 204       $this->calculated['bottom_inner_padding'] = $this->parameter['x_inner_padding'];
 205       if (($this->parameter['x_ticks_colour'] != 'none') && ($this->parameter['tick_length'] < 0))
 206         $this->calculated['bottom_inner_padding'] -= $this->parameter['tick_length'];
 207       $this->calculated['boundary_box']['bottom'] -= $this->calculated['bottom_inner_padding'];
 208
 209       $this->calculated['left_inner_padding'] = $this->parameter['y_inner_padding'];
 210       if ($this->parameter['y_axis_text_left']) {
 211         if (($this->parameter['y_ticks_colour'] != 'none') && ($this->parameter['tick_length'] < 0))
 212           $this->calculated['left_inner_padding'] -= $this->parameter['tick_length'];
 213       }
 214       $this->calculated['boundary_box']['left'] += $this->calculated['left_inner_padding'];
 215
 216       $this->calculated['right_inner_padding'] = $this->parameter['y_inner_padding'];
 217       if ($this->parameter['y_axis_text_right']) {
 218         if (($this->parameter['y_ticks_colour'] != 'none') && ($this->parameter['tick_length'] < 0))
 219           $this->calculated['right_inner_padding'] -= $this->parameter['tick_length'];
 220       }
 221       $this->calculated['boundary_box']['right'] -= $this->calculated['right_inner_padding'];
 222
 223       // boundaryBox now has coords for plotting area.
 224       $this->calculated['inner_border'] = $this->calculated['boundary_box'];
 225
 226       $this->init_data();
 227       $this->init_x_ticks();
 228       $this->init_y_ticks();
 229     }
 230
 231     function draw_text() {
 232       $colour = $this->parameter['outer_background'];
 233       if ($colour != 'none') $this->draw_rectangle($this->calculated['outer_border'], $colour, 'fill'); // graph background
 234
 235       // draw border around image
 236       $colour = $this->parameter['outer_border'];
 237       if ($colour != 'none') $this->draw_rectangle($this->calculated['outer_border'], $colour, 'box'); // graph border
 238
 239       $this->draw_title();
 240       $this->draw_x_label();
 241       $this->draw_y_label_left();
 242       $this->draw_y_label_right();
 243       $this->draw_x_axis();
 244       $this->draw_y_axis();
 245       if      ($this->calculated['y_axis_left']['has_data'])  $this->draw_zero_axis_left();  // either draw zero axis on left
 246       else if ($this->calculated['y_axis_right']['has_data']) $this->draw_zero_axis_right(); // ... or right.
 247       $this->draw_legend();
 248
 249       // draw border around plot area
 250       $colour = $this->parameter['inner_background'];
 251       if ($colour != 'none') $this->draw_rectangle($this->calculated['inner_border'], $colour, 'fill'); // graph background
 252
 253       // draw border around image
 254       $colour = $this->parameter['inner_border'];
 255       if ($colour != 'none') $this->draw_rectangle($this->calculated['inner_border'], $colour, $this->parameter['inner_border_type']); // graph border
 256     }
 257
 258     function draw_stack() {
 259       $this->init();
 260       $this->draw_text();
 261
 262       $yOrder = $this->y_order; // save y_order data.
 263       // iterate over each data set. order is very important if you want to see data correctly. remember shadows!!
 264       foreach ($yOrder as $set) {
 265         $this->y_order = array($set);
 266         $this->init_data();
 267         $this->draw_data();
 268       }
 269       $this->y_order = $yOrder; // revert y_order data.
 270
 271       $this->output();
 272     }
 273
 274     function draw() {
 275       $this->init();
 276       $this->draw_text();
 277       $this->draw_data();
 278       $this->output();
 279     }
 280
 281     // draw a data set
 282     function draw_set($order, $set, $offset) {
 283       if ($offset) @$this->init_variable($colour, $this->y_format[$set]['shadow'], $this->parameter['shadow']);
 284       else $colour  = $this->y_format[$set]['colour'];
 285       @$this->init_variable($point,      $this->y_format[$set]['point'],      'none');
 286       @$this->init_variable($pointSize,  $this->y_format[$set]['point_size'],  $this->parameter['point_size']);
 287       @$this->init_variable($line,       $this->y_format[$set]['line'],       'none');
 288       @$this->init_variable($brushType,  $this->y_format[$set]['brush_type'],  $this->parameter['brush_type']);
 289       @$this->init_variable($brushSize,  $this->y_format[$set]['brush_size'],  $this->parameter['brush_size']);
 290       @$this->init_variable($bar,        $this->y_format[$set]['bar'],        'none');
 291       @$this->init_variable($barSize,    $this->y_format[$set]['bar_size'],    $this->parameter['bar_size']);
 292       @$this->init_variable($area,       $this->y_format[$set]['area'],       'none');
 293
 294       $lastX = 0;
 295       $lastY = 'none';
 296       $fromX = 0;
 297       $fromY = 'none';
 298
 299       //print "set $set<br />";
 300       //expand_pre($this->calculated['y_plot']);
 301
 302       foreach ($this->x_data as $index => $x) {
 303         //print "index $index<br />";
 304         $thisY = $this->calculated['y_plot'][$set][$index];
 305         $thisX = $this->calculated['x_plot'][$index];
 306
 307         //print "$thisX, $thisY <br />";
 308
 309         if (($bar!='none') && (string)$thisY != 'none') {
 310             if (isset($this->offset_relation[$set]) && $relatedset = $this->offset_relation[$set]) {
 311                 $yoffset = $this->calculated['y_plot'][$relatedset][$index];                // Moodle
 312             } else {                                                                        // Moodle
 313                 $yoffset = 0;                                                               // Moodle
 314             }                                                                               // Moodle
 315             //$this->bar($thisX, $thisY, $bar, $barSize, $colour, $offset, $set);           // Moodle
 316             $this->bar($thisX, $thisY, $bar, $barSize, $colour, $offset, $set, $yoffset);   // Moodle
 317         }
 318
 319         if (($area!='none') && (((string)$lastY != 'none') && ((string)$thisY != 'none')))
 320           $this->area($lastX, $lastY, $thisX, $thisY, $area, $colour, $offset);
 321
 322         if (($point!='none') && (string)$thisY != 'none') $this->plot($thisX, $thisY, $point, $pointSize, $colour, $offset);
 323
 324         if (($line!='none') && ((string)$thisY != 'none')) {
 325           if ((string)$fromY != 'none')
 326             $this->line($fromX, $fromY, $thisX, $thisY, $line, $brushType, $brushSize, $colour, $offset);
 327
 328           $fromY = $thisY; // start next line from here
 329           $fromX = $thisX; // ...
 330         } else {
 331           $fromY = 'none';
 332           $fromX = 'none';
 333         }
 334
 335         $lastX = $thisX;
 336         $lastY = $thisY;
 337       }
 338     }
 339
 340     function draw_data() {
 341       // cycle thru y data to be plotted
 342       // first check for drop shadows...
 343       foreach ($this->y_order as $order => $set) {
 344         @$this->init_variable($offset, $this->y_format[$set]['shadow_offset'], $this->parameter['shadow_offset']);
 345         @$this->init_variable($colour, $this->y_format[$set]['shadow'], $this->parameter['shadow']);
 346         if ($colour != 'none') $this->draw_set($order, $set, $offset);
 347
 348       }
 349
 350       // then draw data
 351       foreach ($this->y_order as $order => $set) {
 352         $this->draw_set($order, $set, 0);
 353       }
 354     }
 355
 356     function draw_legend() {
 357       $position      = $this->parameter['legend'];
 358       if ($position == 'none') return; // abort if no border
 359
 360       $borderColour  = $this->parameter['legend_border'];
 361       $offset        = $this->parameter['legend_offset'];
 362       $padding       = $this->parameter['legend_padding'];
 363       $height        = $this->calculated['legend']['boundary_box_all']['height'];
 364       $width         = $this->calculated['legend']['boundary_box_all']['width'];
 365       $graphTop      = $this->calculated['boundary_box']['top'];
 366       $graphBottom   = $this->calculated['boundary_box']['bottom'];
 367       $graphLeft     = $this->calculated['boundary_box']['left'];
 368       $graphRight    = $this->calculated['boundary_box']['right'];
 369       $outsideRight  = $this->calculated['outer_border']['right'];
 370       $outsideBottom = $this->calculated['outer_border']['bottom'];
 371       switch ($position) {
 372         case 'top-left':
 373           $top    = $graphTop  + $offset;
 374           $bottom = $graphTop  + $height + $offset;
 375           $left   = $graphLeft + $offset;
 376           $right  = $graphLeft + $width + $offset;
 377
 378           break;
 379         case 'top-right':
 380           $top    = $graphTop   + $offset;
 381           $bottom = $graphTop   + $height + $offset;
 382           $left   = $graphRight - $width - $offset;
 383           $right  = $graphRight - $offset;
 384
 385           break;
 386         case 'bottom-left':
 387           $top    = $graphBottom - $height - $offset;
 388           $bottom = $graphBottom - $offset;
 389           $left   = $graphLeft   + $offset;
 390           $right  = $graphLeft   + $width + $offset;
 391
 392           break;
 393         case 'bottom-right':
 394           $top    = $graphBottom - $height - $offset;
 395           $bottom = $graphBottom - $offset;
 396           $left   = $graphRight  - $width - $offset;
 397           $right  = $graphRight  - $offset;
 398           break;
 399
 400         case 'outside-top' :
 401           $top    = $graphTop;
 402           $bottom = $graphTop     + $height;
 403           $left   = $outsideRight - $width - $offset;
 404           $right  = $outsideRight - $offset;
 405           break;
 406
 407         case 'outside-bottom' :
 408           $top    = $graphBottom  - $height;
 409           $bottom = $graphBottom;
 410           $left   = $outsideRight - $width - $offset;
 411           $right  = $outsideRight - $offset;
 412          break;
 413
 414         case 'outside-left' :
 415           $top    = $outsideBottom - $height - $offset;
 416           $bottom = $outsideBottom - $offset;
 417           $left   = $graphLeft;
 418           $right  = $graphLeft     + $width;
 419          break;
 420
 421         case 'outside-right' :
 422           $top    = $outsideBottom - $height - $offset;
 423           $bottom = $outsideBottom - $offset;
 424           $left   = $graphRight    - $width;
 425           $right  = $graphRight;
 426           break;
 427         default: // default is top left. no particular reason.
 428           $top    = $this->calculated['boundary_box']['top'];
 429           $bottom = $this->calculated['boundary_box']['top'] + $this->calculated['legend']['boundary_box_all']['height'];
 430           $left   = $this->calculated['boundary_box']['left'];
 431           $right  = $this->calculated['boundary_box']['right'] + $this->calculated['legend']['boundary_box_all']['width'];
 432
 433     }
 434       // legend border
 435       if($borderColour!='none') $this->draw_rectangle(array('top' => $top,
 436                                                             'left' => $left,
 437                                                             'bottom' => $bottom,
 438                                                             'right' => $right), $this->parameter['legend_border'], 'box');
 439
 440       // legend text
 441       $legendText = array('points' => $this->parameter['legend_size'],
 442                           'angle'  => 0,
 443                           'font'   => $this->parameter['legend_font'],
 444                           'colour' => $this->parameter['legend_colour']);
 445
 446       $box = $this->calculated['legend']['boundary_box_max']['height']; // use max height for legend square size.
 447       $x = $left + $padding;
 448       $x_text = $x + $box * 2;
 449       $y = $top + $padding;
 450
 451       foreach ($this->y_order as $set) {
 452         $legendText['text'] = $this->calculated['legend']['text'][$set];
 453         if ($legendText['text'] != 'none') {
 454           // if text exists then draw box and text
 455           $boxColour = $this->colour[$this->y_format[$set]['colour']];
 456
 457           // draw box
 458           ImageFilledRectangle($this->image, $x, $y, $x + $box, $y + $box, $boxColour);
 459
 460           // draw text
 461           $coords = array('x' => $x + $box * 2, 'y' => $y, 'reference' => 'top-left');
 462           $legendText['boundary_box'] = $this->calculated['legend']['boundary_box'][$set];
 463           $this->update_boundaryBox($legendText['boundary_box'], $coords);
 464           $this->print_TTF($legendText);
 465           $y += $padding + $box;
 466         }
 467       }
 468
 469     }
 470
 471     function draw_y_label_right() {
 472       if (!$this->parameter['y_label_right']) return;
 473       $x = $this->calculated['boundary_box']['right'] + $this->parameter['y_inner_padding'];
 474       if ($this->parameter['y_axis_text_right']) $x += $this->calculated['y_axis_right']['boundary_box_max']['width']
 475                                                + $this->calculated['right_inner_padding'];
 476       $y = ($this->calculated['boundary_box']['bottom'] + $this->calculated['boundary_box']['top']) / 2;
 477
 478       $label = $this->calculated['y_label_right'];
 479       $coords = array('x' => $x, 'y' => $y, 'reference' => 'left-center');
 480       $this->update_boundaryBox($label['boundary_box'], $coords);
 481       $this->print_TTF($label);
 482     }
 483
 484
 485     function draw_y_label_left() {
 486       if (!$this->parameter['y_label_left']) return;
 487       $x = $this->calculated['boundary_box']['left'] - $this->parameter['y_inner_padding'];
 488       if ($this->parameter['y_axis_text_left']) $x -= $this->calculated['y_axis_left']['boundary_box_max']['width']
 489                                                + $this->calculated['left_inner_padding'];
 490       $y = ($this->calculated['boundary_box']['bottom'] + $this->calculated['boundary_box']['top']) / 2;
 491
 492       $label = $this->calculated['y_label_left'];
 493       $coords = array('x' => $x, 'y' => $y, 'reference' => 'right-center');
 494       $this->update_boundaryBox($label['boundary_box'], $coords);
 495       $this->print_TTF($label);
 496     }
 497
 498     function draw_title() {
 499       if (!$this->parameter['title']) return;
 500       //$y = $this->calculated['outside_border']['top'] + $this->parameter['outer_padding'];
 501       $y = $this->calculated['boundary_box']['top'] - $this->parameter['outer_padding'];
 502       $x = ($this->calculated['boundary_box']['right'] + $this->calculated['boundary_box']['left']) / 2;
 503       $label = $this->calculated['title'];
 504       $coords = array('x' => $x, 'y' => $y, 'reference' => 'bottom-center');
 505       $this->update_boundaryBox($label['boundary_box'], $coords);
 506       $this->print_TTF($label);
 507     }
 508
 509     function draw_x_label() {
 510       if (!$this->parameter['x_label']) return;
 511       $y = $this->calculated['boundary_box']['bottom'] + $this->parameter['x_inner_padding'];
 512       if ($this->parameter['x_axis_text']) $y += $this->calculated['x_axis']['boundary_box_max']['height']
 513                                               + $this->calculated['bottom_inner_padding'];
 514       $x = ($this->calculated['boundary_box']['right'] + $this->calculated['boundary_box']['left']) / 2;
 515       $label = $this->calculated['x_label'];
 516       $coords = array('x' => $x, 'y' => $y, 'reference' => 'top-center');
 517       $this->update_boundaryBox($label['boundary_box'], $coords);
 518       $this->print_TTF($label);
 519     }
 520
 521     function draw_zero_axis_left() {
 522       $colour = $this->parameter['zero_axis'];
 523       if ($colour == 'none') return;
 524       // draw zero axis on left hand side
 525       $this->calculated['zero_axis'] = round($this->calculated['boundary_box']['top']  + ($this->calculated['y_axis_left']['max'] * $this->calculated['y_axis_left']['factor']));
 526       ImageLine($this->image, $this->calculated['boundary_box']['left'], $this->calculated['zero_axis'], $this->calculated['boundary_box']['right'], $this->calculated['zero_axis'], $this->colour[$colour]);
 527     }
 528
 529     function draw_zero_axis_right() {
 530       $colour = $this->parameter['zero_axis'];
 531       if ($colour == 'none') return;
 532       // draw zero axis on right hand side
 533       $this->calculated['zero_axis'] = round($this->calculated['boundary_box']['top']  + ($this->calculated['y_axis_right']['max'] * $this->calculated['y_axis_right']['factor']));
 534       ImageLine($this->image, $this->calculated['boundary_box']['left'], $this->calculated['zero_axis'], $this->calculated['boundary_box']['right'], $this->calculated['zero_axis'], $this->colour[$colour]);
 535     }
 536
 537     function draw_x_axis() {
 538       $gridColour  = $this->colour[$this->parameter['grid_colour']];
 539       $tickColour  = $this->colour[$this->parameter['x_ticks_colour']];
 540       $axis_colour  = $this->parameter['axis_colour'];
 541       $xGrid       = $this->parameter['x_grid'];
 542       $gridTop     = $this->calculated['boundary_box']['top'];
 543       $gridBottom  = $this->calculated['boundary_box']['bottom'];
 544
 545       if ($this->parameter['tick_length'] >= 0) {
 546         $tickTop     = $this->calculated['boundary_box']['bottom'] - $this->parameter['tick_length'];
 547         $tickBottom  = $this->calculated['boundary_box']['bottom'];
 548         $textBottom  = $tickBottom + $this->calculated['bottom_inner_padding'];
 549       } else {
 550         $tickTop     = $this->calculated['boundary_box']['bottom'];
 551         $tickBottom  = $this->calculated['boundary_box']['bottom'] - $this->parameter['tick_length'];
 552         $textBottom  = $tickBottom + $this->calculated['bottom_inner_padding'];
 553       }
 554
 555       $axis_font    = $this->parameter['axis_font'];
 556       $axis_size    = $this->parameter['axis_size'];
 557       $axis_angle   = $this->parameter['x_axis_angle'];
 558
 559       if ($axis_angle == 0)  $reference = 'top-center';
 560       if ($axis_angle > 0)   $reference = 'top-right';
 561       if ($axis_angle < 0)   $reference = 'top-left';
 562       if ($axis_angle == 90) $reference = 'top-center';
 563
 564       //generic tag information. applies to all axis text.
 565       $axisTag = array('points' => $axis_size, 'angle' => $axis_angle, 'font' => $axis_font, 'colour' => $axis_colour);
 566
 567       foreach ($this->calculated['x_axis']['tick_x'] as $set => $tickX) {
 568         // draw x grid if colour specified
 569         if ($xGrid != 'none') {
 570           switch ($xGrid) {
 571             case 'line':
 572               ImageLine($this->image, round($tickX), round($gridTop), round($tickX), round($gridBottom), $gridColour);
 573               break;
 574              case 'dash':
 575               ImageDashedLine($this->image, round($tickX), round($gridTop), round($tickX), round($gridBottom), $gridColour);
 576               break;
 577           }
 578         }
 579
 580         if ($this->parameter['x_axis_text'] && !($set % $this->parameter['x_axis_text'])) { // test if tick should be displayed
 581           // draw tick
 582           if ($tickColour != 'none')
 583             ImageLine($this->image, round($tickX), round($tickTop), round($tickX), round($tickBottom), $tickColour);
 584
 585           // draw axis text
 586           $coords = array('x' => $tickX, 'y' => $textBottom, 'reference' => $reference);
 587           $axisTag['text'] = $this->calculated['x_axis']['text'][$set];
 588           $axisTag['boundary_box'] = $this->calculated['x_axis']['boundary_box'][$set];
 589           $this->update_boundaryBox($axisTag['boundary_box'], $coords);
 590           $this->print_TTF($axisTag);
 591         }
 592       }
 593     }
 594
 595     function draw_y_axis() {
 596       $gridColour  = $this->colour[$this->parameter['grid_colour']];
 597       $tickColour  = $this->colour[$this->parameter['y_ticks_colour']];
 598       $axis_colour  = $this->parameter['axis_colour'];
 599       $yGrid       = $this->parameter['y_grid'];
 600       $gridLeft    = $this->calculated['boundary_box']['left'];
 601       $gridRight   = $this->calculated['boundary_box']['right'];
 602
 603       // axis font information
 604       $axis_font    = $this->parameter['axis_font'];
 605       $axis_size    = $this->parameter['axis_size'];
 606       $axis_angle   = $this->parameter['y_axis_angle'];
 607       $axisTag = array('points' => $axis_size, 'angle' => $axis_angle, 'font' => $axis_font, 'colour' => $axis_colour);
 608
 609
 610       if ($this->calculated['y_axis_left']['has_data']) {
 611         // LEFT HAND SIDE
 612         // left and right coords for ticks
 613         if ($this->parameter['tick_length'] >= 0) {
 614           $tickLeft     = $this->calculated['boundary_box']['left'];
 615           $tickRight    = $this->calculated['boundary_box']['left'] + $this->parameter['tick_length'];
 616         } else {
 617           $tickLeft     = $this->calculated['boundary_box']['left'] + $this->parameter['tick_length'];
 618           $tickRight    = $this->calculated['boundary_box']['left'];
 619         }
 620         $textRight      = $tickLeft - $this->calculated['left_inner_padding'];
 621
 622         if ($axis_angle == 0)  $reference = 'right-center';
 623         if ($axis_angle > 0)   $reference = 'right-top';
 624         if ($axis_angle < 0)   $reference = 'right-bottom';
 625         if ($axis_angle == 90) $reference = 'right-center';
 626
 627         foreach ($this->calculated['y_axis']['tick_y'] as $set => $tickY) {
 628           // draw y grid if colour specified
 629           if ($yGrid != 'none') {
 630             switch ($yGrid) {
 631               case 'line':
 632                 ImageLine($this->image, round($gridLeft), round($tickY), round($gridRight), round($tickY), $gridColour);
 633                 break;
 634                case 'dash':
 635                 ImageDashedLine($this->image, round($gridLeft), round($tickY), round($gridRight), round($tickY), $gridColour);
 636                 break;
 637             }
 638           }
 639
 640           // y axis text
 641           if ($this->parameter['y_axis_text_left'] && !($set % $this->parameter['y_axis_text_left'])) { // test if tick should be displayed
 642             // draw tick
 643             if ($tickColour != 'none')
 644               ImageLine($this->image, round($tickLeft), round($tickY), round($tickRight), round($tickY), $tickColour);
 645
 646             // draw axis text...
 647             $coords = array('x' => $textRight, 'y' => $tickY, 'reference' => $reference);
 648             $axisTag['text'] = $this->calculated['y_axis_left']['text'][$set];
 649             $axisTag['boundary_box'] = $this->calculated['y_axis_left']['boundary_box'][$set];
 650             $this->update_boundaryBox($axisTag['boundary_box'], $coords);
 651             $this->print_TTF($axisTag);
 652           }
 653         }
 654       }
 655
 656       if ($this->calculated['y_axis_right']['has_data']) {
 657         // RIGHT HAND SIDE
 658         // left and right coords for ticks
 659         if ($this->parameter['tick_length'] >= 0) {
 660           $tickLeft     = $this->calculated['boundary_box']['right'] - $this->parameter['tick_length'];
 661           $tickRight    = $this->calculated['boundary_box']['right'];
 662         } else {
 663           $tickLeft     = $this->calculated['boundary_box']['right'];
 664           $tickRight    = $this->calculated['boundary_box']['right'] - $this->parameter['tick_length'];
 665         }
 666         $textLeft       = $tickRight+ $this->calculated['left_inner_padding'];
 667
 668         if ($axis_angle == 0)  $reference = 'left-center';
 669         if ($axis_angle > 0)   $reference = 'left-bottom';
 670         if ($axis_angle < 0)   $reference = 'left-top';
 671         if ($axis_angle == 90) $reference = 'left-center';
 672
 673         foreach ($this->calculated['y_axis']['tick_y'] as $set => $tickY) {
 674           if (!$this->calculated['y_axis_left']['has_data'] && $yGrid != 'none') { // draw grid if not drawn already (above)
 675             switch ($yGrid) {
 676               case 'line':
 677                 ImageLine($this->image, round($gridLeft), round($tickY), round($gridRight), round($tickY), $gridColour);
 678                 break;
 679                case 'dash':
 680                 ImageDashedLine($this->image, round($gridLeft), round($tickY), round($gridRight), round($tickY), $gridColour);
 681                 break;
 682             }
 683           }
 684
 685           if ($this->parameter['y_axis_text_right'] && !($set % $this->parameter['y_axis_text_right'])) { // test if tick should be displayed
 686             // draw tick
 687             if ($tickColour != 'none')
 688               ImageLine($this->image, round($tickLeft), round($tickY), round($tickRight), round($tickY), $tickColour);
 689
 690             // draw axis text...
 691             $coords = array('x' => $textLeft, 'y' => $tickY, 'reference' => $reference);
 692             $axisTag['text'] = $this->calculated['y_axis_right']['text'][$set];
 693             $axisTag['boundary_box'] = $this->calculated['y_axis_left']['boundary_box'][$set];
 694             $this->update_boundaryBox($axisTag['boundary_box'], $coords);
 695             $this->print_TTF($axisTag);
 696           }
 697         }
 698       }
 699     }
 700
 701     function init_data() {
 702       $this->calculated['y_plot'] = array(); // array to hold pixel plotting coords for y axis
 703       $height = $this->calculated['boundary_box']['bottom'] - $this->calculated['boundary_box']['top'];
 704       $width  = $this->calculated['boundary_box']['right'] - $this->calculated['boundary_box']['left'];
 705
 706       // calculate pixel steps between axis ticks.
 707       $this->calculated['y_axis']['step'] = $height / ($this->parameter['y_axis_gridlines'] - 1);
 708
 709       // calculate x ticks spacing taking into account x offset for ticks.
 710       $extraTick  = 2 * $this->parameter['x_offset']; // extra tick to account for padding
 711       $numTicks = $this->calculated['x_axis']['num_ticks'] - 1;    // number of x ticks
 712
 713       // Hack by rodger to avoid division by zero, see bug 1231
 714       if ($numTicks==0) $numTicks=1;
 715
 716       $this->calculated['x_axis']['step'] = $width / ($numTicks + $extraTick);
 717       $widthPlot = $width - ($this->calculated['x_axis']['step'] * $extraTick);
 718       $this->calculated['x_axis']['step'] = $widthPlot / $numTicks;
 719
 720       //calculate factor for transforming x,y physical coords to logical coords for right hand y_axis.
 721       $y_range = $this->calculated['y_axis_right']['max'] - $this->calculated['y_axis_right']['min'];
 722       $y_range = ($y_range ? $y_range : 1);
 723       $this->calculated['y_axis_right']['factor'] = $height / $y_range;
 724
 725       //calculate factor for transforming x,y physical coords to logical coords for left hand axis.
 726       $yRange = $this->calculated['y_axis_left']['max'] - $this->calculated['y_axis_left']['min'];
 727       $yRange = ($yRange ? $yRange : 1);
 728       $this->calculated['y_axis_left']['factor'] = $height / $yRange;
 729       if ($this->parameter['x_axis_gridlines'] != 'auto') {
 730         $xRange = $this->calculated['x_axis']['max'] - $this->calculated['x_axis']['min'];
 731         $xRange = ($xRange ? $xRange : 1);
 732         $this->calculated['x_axis']['factor'] = $widthPlot / $xRange;
 733       }
 734
 735       //expand_pre($this->calculated['boundary_box']);
 736       // cycle thru all data sets...
 737       $this->calculated['num_bars'] = 0;
 738       foreach ($this->y_order as $order => $set) {
 739         // determine how many bars there are
 740         if (isset($this->y_format[$set]['bar']) && ($this->y_format[$set]['bar'] != 'none')) {
 741           $this->calculated['bar_offset_index'][$set] = $this->calculated['num_bars']; // index to relate bar with data set.
 742           $this->calculated['num_bars']++;
 743         }
 744
 745         // calculate y coords for plotting data
 746         foreach ($this->x_data as $index => $x) {
 747           $this->calculated['y_plot'][$set][$index] = $this->y_data[$set][$index];
 748
 749           if ((string)$this->y_data[$set][$index] != 'none') {
 750
 751             if (isset($this->y_format[$set]['y_axis']) && $this->y_format[$set]['y_axis'] == 'right') {
 752               $this->calculated['y_plot'][$set][$index] =
 753                 round(($this->y_data[$set][$index] - $this->calculated['y_axis_right']['min'])
 754                   * $this->calculated['y_axis_right']['factor']);
 755             } else {
 756               //print "$set $index<br />";
 757               $this->calculated['y_plot'][$set][$index] =
 758                 round(($this->y_data[$set][$index] - $this->calculated['y_axis_left']['min'])
 759                   * $this->calculated['y_axis_left']['factor']);
 760             }
 761
 762           }
 763         }
 764       }
 765       //print "factor ".$this->calculated['x_axis']['factor']."<br />";
 766       //expand_pre($this->calculated['x_plot']);
 767
 768       // calculate bar parameters if bars are to be drawn.
 769       if ($this->calculated['num_bars']) {
 770         $xStep       = $this->calculated['x_axis']['step'];
 771         $totalWidth  = $this->calculated['x_axis']['step'] - $this->parameter['bar_spacing'];
 772         $barWidth    = $totalWidth / $this->calculated['num_bars'];
 773
 774         $barX = ($barWidth - $totalWidth) / 2; // starting x offset
 775         for ($i=0; $i < $this->calculated['num_bars']; $i++) {
 776           $this->calculated['bar_offset_x'][$i] = $barX;
 777           $barX += $barWidth; // add width of bar to x offset.
 778         }
 779         $this->calculated['bar_width'] = $barWidth;
 780       }
 781
 782
 783     }
 784
 785     function init_x_ticks() {
 786       // get coords for x axis ticks and data plots
 787       //$xGrid       = $this->parameter['x_grid'];
 788       $xStep       = $this->calculated['x_axis']['step'];
 789       $ticksOffset = $this->parameter['x_offset']; // where to start drawing ticks relative to y axis.
 790       $gridLeft    = $this->calculated['boundary_box']['left'] + ($xStep * $ticksOffset); // grid x start
 791       $tickX       = $gridLeft; // tick x coord
 792
 793       foreach ($this->calculated['x_axis']['text'] as $set => $value) {
 794         //print "index: $set<br />";
 795         // x tick value
 796         $this->calculated['x_axis']['tick_x'][$set] = $tickX;
 797         // if num ticks is auto then x plot value is same as x  tick
 798         if ($this->parameter['x_axis_gridlines'] == 'auto') $this->calculated['x_plot'][$set] = round($tickX);
 799         //print $this->calculated['x_plot'][$set].'<br />';
 800         $tickX += $xStep;
 801       }
 802
 803       //print "xStep: $xStep <br />";
 804       // if numeric x axis then calculate x coords for each data point. this is seperate from x ticks.
 805       $gridX = $gridLeft;
 806       if (empty($this->calculated['x_axis']['factor'])) {
 807           $this->calculated['x_axis']['factor'] = 0;
 808       }
 809       if (empty($this->calculated['x_axis']['min'])) {
 810           $this->calculated['x_axis']['min'] = 0;
 811       }
 812       $factor = $this->calculated['x_axis']['factor'];
 813       $min = $this->calculated['x_axis']['min'];
 814
 815       if ($this->parameter['x_axis_gridlines'] != 'auto') {
 816         foreach ($this->x_data as $index => $x) {
 817           //print "index: $index, x: $x<br />";
 818           $offset = $x - $this->calculated['x_axis']['min'];
 819
 820           //$gridX = ($offset * $this->calculated['x_axis']['factor']);
 821           //print "offset: $offset <br />";
 822           //$this->calculated['x_plot'][$set] = $gridLeft + ($offset * $this->calculated['x_axis']['factor']);
 823
 824           $this->calculated['x_plot'][$index] = $gridLeft + ($x - $min) * $factor;
 825
 826           //print $this->calculated['x_plot'][$set].'<br />';
 827         }
 828       }
 829       //expand_pre($this->calculated['boundary_box']);
 830       //print "factor ".$this->calculated['x_axis']['factor']."<br />";
 831       //expand_pre($this->calculated['x_plot']);
 832     }
 833
 834     function init_y_ticks() {
 835       // get coords for y axis ticks
 836
 837       $yStep      = $this->calculated['y_axis']['step'];
 838       $gridBottom = $this->calculated['boundary_box']['bottom'];
 839       $tickY      = $gridBottom; // tick y coord
 840
 841       for ($i = 0; $i < $this->parameter['y_axis_gridlines']; $i++) {
 842         $this->calculated['y_axis']['tick_y'][$i] = $tickY;
 843         $tickY   -= $yStep;
 844       }
 845
 846     }
 847
 848     function init_labels() {
 849       if ($this->parameter['title']) {
 850         $size = $this->get_boundaryBox(
 851           array('points' => $this->parameter['title_size'],
 852                 'angle'  => 0,
 853                 'font'   => $this->parameter['title_font'],
 854                 'text'   => $this->parameter['title']));
 855         $this->calculated['title']['boundary_box']  = $size;
 856         $this->calculated['title']['text']         = $this->parameter['title'];
 857         $this->calculated['title']['font']         = $this->parameter['title_font'];
 858         $this->calculated['title']['points']       = $this->parameter['title_size'];
 859         $this->calculated['title']['colour']       = $this->parameter['title_colour'];
 860         $this->calculated['title']['angle']        = 0;
 861
 862         $this->calculated['boundary_box']['top'] += $size['height'] + $this->parameter['outer_padding'];
 863         //$this->calculated['boundary_box']['top'] += $size['height'];
 864
 865       } else $this->calculated['title']['boundary_box'] = $this->get_null_size();
 866
 867       if ($this->parameter['y_label_left']) {
 868         $this->calculated['y_label_left']['text']    = $this->parameter['y_label_left'];
 869         $this->calculated['y_label_left']['angle']   = $this->parameter['y_label_angle'];
 870         $this->calculated['y_label_left']['font']    = $this->parameter['label_font'];
 871         $this->calculated['y_label_left']['points']  = $this->parameter['label_size'];
 872         $this->calculated['y_label_left']['colour']  = $this->parameter['label_colour'];
 873
 874         $size = $this->get_boundaryBox($this->calculated['y_label_left']);
 875         $this->calculated['y_label_left']['boundary_box']  = $size;
 876         //$this->calculated['boundary_box']['left'] += $size['width'] + $this->parameter['inner_padding'];
 877         $this->calculated['boundary_box']['left'] += $size['width'];
 878
 879       } else $this->calculated['y_label_left']['boundary_box'] = $this->get_null_size();
 880
 881       if ($this->parameter['y_label_right']) {
 882         $this->calculated['y_label_right']['text']    = $this->parameter['y_label_right'];
 883         $this->calculated['y_label_right']['angle']   = $this->parameter['y_label_angle'];
 884         $this->calculated['y_label_right']['font']    = $this->parameter['label_font'];
 885         $this->calculated['y_label_right']['points']  = $this->parameter['label_size'];
 886         $this->calculated['y_label_right']['colour']  = $this->parameter['label_colour'];
 887
 888         $size = $this->get_boundaryBox($this->calculated['y_label_right']);
 889         $this->calculated['y_label_right']['boundary_box']  = $size;
 890         //$this->calculated['boundary_box']['right'] -= $size['width'] + $this->parameter['inner_padding'];
 891         $this->calculated['boundary_box']['right'] -= $size['width'];
 892
 893       } else $this->calculated['y_label_right']['boundary_box'] = $this->get_null_size();
 894
 895       if ($this->parameter['x_label']) {
 896         $this->calculated['x_label']['text']         = $this->parameter['x_label'];
 897         $this->calculated['x_label']['angle']        = $this->parameter['x_label_angle'];
 898         $this->calculated['x_label']['font']         = $this->parameter['label_font'];
 899         $this->calculated['x_label']['points']       = $this->parameter['label_size'];
 900         $this->calculated['x_label']['colour']       = $this->parameter['label_colour'];
 901
 902         $size = $this->get_boundaryBox($this->calculated['x_label']);
 903         $this->calculated['x_label']['boundary_box']  = $size;
 904         //$this->calculated['boundary_box']['bottom'] -= $size['height'] + $this->parameter['inner_padding'];
 905         $this->calculated['boundary_box']['bottom'] -= $size['height'];
 906
 907       } else $this->calculated['x_label']['boundary_box'] = $this->get_null_size();
 908
 909     }
 910
 911
 912     function init_legend() {
 913       $this->calculated['legend'] = array(); // array to hold calculated values for legend.
 914       //$this->calculated['legend']['boundary_box_max'] = array('height' => 0, 'width' => 0);
 915       $this->calculated['legend']['boundary_box_max'] = $this->get_null_size();
 916       if ($this->parameter['legend'] == 'none') return;
 917
 918       $position = $this->parameter['legend'];
 919       $numSets = 0; // number of data sets with legends.
 920       $sumTextHeight = 0; // total of height of all legend text items.
 921       $width = 0;
 922       $height = 0;
 923
 924       foreach ($this->y_order as $set) {
 925        $text = isset($this->y_format[$set]['legend']) ? $this->y_format[$set]['legend'] : 'none';
 926        $size = $this->get_boundaryBox(
 927          array('points' => $this->parameter['legend_size'],
 928                'angle'  => 0,
 929                'font'   => $this->parameter['legend_font'],
 930                'text'   => $text));
 931
 932        $this->calculated['legend']['boundary_box'][$set] = $size;
 933        $this->calculated['legend']['text'][$set]        = $text;
 934        //$this->calculated['legend']['font'][$set]        = $this->parameter['legend_font'];
 935        //$this->calculated['legend']['points'][$set]      = $this->parameter['legend_size'];
 936        //$this->calculated['legend']['angle'][$set]       = 0;
 937
 938        if ($text && $text!='none') {
 939          $numSets++;
 940          $sumTextHeight += $size['height'];
 941        }
 942
 943        if ($size['width'] > $this->calculated['legend']['boundary_box_max']['width'])
 944          $this->calculated['legend']['boundary_box_max'] = $size;
 945       }
 946
 947       $offset  = $this->parameter['legend_offset'];  // offset in pixels of legend box from graph border.
 948       $padding = $this->parameter['legend_padding']; // padding in pixels around legend text.
 949       $textWidth = $this->calculated['legend']['boundary_box_max']['width']; // width of largest legend item.
 950       $textHeight = $this->calculated['legend']['boundary_box_max']['height']; // use height as size to use for colour square in legend.
 951       $width = $padding * 2 + $textWidth + $textHeight * 2;  // left and right padding + maximum text width + space for square
 952       $height = ($padding + $textHeight) * $numSets + $padding; // top and bottom padding + padding between text + text.
 953
 954       $this->calculated['legend']['boundary_box_all'] = array('width'     => $width,
 955                                                             'height'    => $height,
 956                                                             'offset'    => $offset,
 957                                                             'reference' => $position);
 958
 959       switch ($position) { // move in right or bottom if legend is outside data plotting area.
 960         case 'outside-top' :
 961           $this->calculated['boundary_box']['right']      -= $offset + $width; // move in right hand side
 962           break;
 963
 964         case 'outside-bottom' :
 965           $this->calculated['boundary_box']['right']      -= $offset + $width; // move in right hand side
 966           break;
 967
 968         case 'outside-left' :
 969           $this->calculated['boundary_box']['bottom']      -= $offset + $height; // move in right hand side
 970           break;
 971
 972         case 'outside-right' :
 973           $this->calculated['boundary_box']['bottom']      -= $offset + $height; // move in right hand side
 974           break;
 975       }
 976     }
 977
 978     function init_y_axis() {
 979       $this->calculated['y_axis_left'] = array(); // array to hold calculated values for y_axis on left.
 980       $this->calculated['y_axis_left']['boundary_box_max'] = $this->get_null_size();
 981       $this->calculated['y_axis_right'] = array(); // array to hold calculated values for y_axis on right.
 982       $this->calculated['y_axis_right']['boundary_box_max'] = $this->get_null_size();
 983
 984       $axis_font       = $this->parameter['axis_font'];
 985       $axis_size       = $this->parameter['axis_size'];
 986       $axis_colour     = $this->parameter['axis_colour'];
 987       $axis_angle      = $this->parameter['y_axis_angle'];
 988       $y_tick_labels   = $this->y_tick_labels;
 989
 990       $this->calculated['y_axis_left']['has_data'] = FALSE;
 991       $this->calculated['y_axis_right']['has_data'] = FALSE;
 992
 993       // find min and max y values.
 994       $minLeft = $this->parameter['y_min_left'];
 995       $maxLeft = $this->parameter['y_max_left'];
 996       $minRight = $this->parameter['y_min_right'];
 997       $maxRight = $this->parameter['y_max_right'];
 998       $dataLeft = array();
 999       $dataRight = array();
1000       foreach ($this->y_order as $order => $set) {
1001         if (isset($this->y_format[$set]['y_axis']) && $this->y_format[$set]['y_axis'] == 'right') {
1002           $this->calculated['y_axis_right']['has_data'] = TRUE;
1003           $dataRight = array_merge($dataRight, $this->y_data[$set]);
1004         } else {
1005           $this->calculated['y_axis_left']['has_data'] = TRUE;
1006           $dataLeft = array_merge($dataLeft, $this->y_data[$set]);
1007         }
1008       }
1009       $dataLeftRange = $this->find_range($dataLeft, $minLeft, $maxLeft, $this->parameter['y_resolution_left']);
1010       $dataRightRange = $this->find_range($dataRight, $minRight, $maxRight, $this->parameter['y_resolution_right']);
1011       $minLeft = $dataLeftRange['min'];
1012       $maxLeft = $dataLeftRange['max'];
1013       $minRight = $dataRightRange['min'];
1014       $maxRight = $dataRightRange['max'];
1015
1016       $this->calculated['y_axis_left']['min']  = $minLeft;
1017       $this->calculated['y_axis_left']['max']  = $maxLeft;
1018       $this->calculated['y_axis_right']['min'] = $minRight;
1019       $this->calculated['y_axis_right']['max'] = $maxRight;
1020
1021       $stepLeft = ($maxLeft - $minLeft) / ($this->parameter['y_axis_gridlines'] - 1);
1022       $startLeft = $minLeft;
1023       $step_right = ($maxRight - $minRight) / ($this->parameter['y_axis_gridlines'] - 1);
1024       $start_right = $minRight;
1025
1026       if ($this->parameter['y_axis_text_left']) {
1027         for ($i = 0; $i < $this->parameter['y_axis_gridlines']; $i++) { // calculate y axis text sizes
1028           // left y axis
1029           if ($y_tick_labels) {
1030             $value = $y_tick_labels[$i];
1031           } else {
1032             $value = number_format($startLeft, $this->parameter['y_decimal_left'], $this->parameter['decimal_point'], $this->parameter['thousand_sep']);
1033           }
1034           $this->calculated['y_axis_left']['data'][$i]  = $startLeft;
1035           $this->calculated['y_axis_left']['text'][$i]  = $value; // text is formatted raw data
1036
1037           $size = $this->get_boundaryBox(
1038             array('points' => $axis_size,
1039                   'font'   => $axis_font,
1040                   'angle'  => $axis_angle,
1041                   'colour' => $axis_colour,
1042                   'text'   => $value));
1043           $this->calculated['y_axis_left']['boundary_box'][$i] = $size;
1044
1045           if ($size['height'] > $this->calculated['y_axis_left']['boundary_box_max']['height'])
1046             $this->calculated['y_axis_left']['boundary_box_max']['height'] = $size['height'];
1047           if ($size['width'] > $this->calculated['y_axis_left']['boundary_box_max']['width'])
1048             $this->calculated['y_axis_left']['boundary_box_max']['width'] = $size['width'];
1049
1050           $startLeft += $stepLeft;
1051         }
1052         $this->calculated['boundary_box']['left'] += $this->calculated['y_axis_left']['boundary_box_max']['width']
1053                                                     + $this->parameter['y_inner_padding'];
1054       }
1055
1056       if ($this->parameter['y_axis_text_right']) {
1057         for ($i = 0; $i < $this->parameter['y_axis_gridlines']; $i++) { // calculate y axis text sizes
1058           // right y axis
1059           $value = number_format($start_right, $this->parameter['y_decimal_right'], $this->parameter['decimal_point'], $this->parameter['thousand_sep']);
1060           $this->calculated['y_axis_right']['data'][$i]  = $start_right;
1061           $this->calculated['y_axis_right']['text'][$i]  = $value; // text is formatted raw data
1062           $size = $this->get_boundaryBox(
1063             array('points' => $axis_size,
1064                   'font'   => $axis_font,
1065                   'angle'  => $axis_angle,
1066                   'colour' => $axis_colour,
1067                   'text'   => $value));
1068           $this->calculated['y_axis_right']['boundary_box'][$i] = $size;
1069
1070           if ($size['height'] > $this->calculated['y_axis_right']['boundary_box_max']['height'])
1071             $this->calculated['y_axis_right']['boundary_box_max'] = $size;
1072           if ($size['width'] > $this->calculated['y_axis_right']['boundary_box_max']['width'])
1073             $this->calculated['y_axis_right']['boundary_box_max']['width'] = $size['width'];
1074
1075           $start_right += $step_right;
1076         }
1077         $this->calculated['boundary_box']['right'] -= $this->calculated['y_axis_right']['boundary_box_max']['width']
1078                                                     + $this->parameter['y_inner_padding'];
1079       }
1080     }
1081
1082     function init_x_axis() {
1083       $this->calculated['x_axis'] = array(); // array to hold calculated values for x_axis.
1084       $this->calculated['x_axis']['boundary_box_max'] = array('height' => 0, 'width' => 0);
1085
1086       $axis_font       = $this->parameter['axis_font'];
1087       $axis_size       = $this->parameter['axis_size'];
1088       $axis_colour     = $this->parameter['axis_colour'];
1089       $axis_angle      = $this->parameter['x_axis_angle'];
1090
1091       // check whether to treat x axis as numeric
1092       if ($this->parameter['x_axis_gridlines'] == 'auto') { // auto means text based x_axis, not numeric...
1093         $this->calculated['x_axis']['num_ticks'] = sizeof($this->x_data);
1094           $data = $this->x_data;
1095           for ($i=0; $i < $this->calculated['x_axis']['num_ticks']; $i++) {
1096             $value = array_shift($data); // grab value from begin of array
1097             $this->calculated['x_axis']['data'][$i]  = $value;
1098             $this->calculated['x_axis']['text'][$i]  = $value; // raw data and text are both the same in this case
1099             $size = $this->get_boundaryBox(
1100               array('points' => $axis_size,
1101                     'font'   => $axis_font,
1102                     'angle'  => $axis_angle,
1103                     'colour' => $axis_colour,
1104                     'text'   => $value));
1105             $this->calculated['x_axis']['boundary_box'][$i] = $size;
1106             if ($size['height'] > $this->calculated['x_axis']['boundary_box_max']['height'])
1107               $this->calculated['x_axis']['boundary_box_max'] = $size;
1108           }
1109
1110       } else { // x axis is numeric so find max min values...
1111         $this->calculated['x_axis']['num_ticks'] = $this->parameter['x_axis_gridlines'];
1112
1113         $min = $this->parameter['x_min'];
1114         $max = $this->parameter['x_max'];
1115         $data = array();
1116         $data = $this->find_range($this->x_data, $min, $max, $this->parameter['x_resolution']);
1117         $min = $data['min'];
1118         $max = $data['max'];
1119         $this->calculated['x_axis']['min'] = $min;
1120         $this->calculated['x_axis']['max'] = $max;
1121
1122         $step = ($max - $min) / ($this->calculated['x_axis']['num_ticks'] - 1);
1123         $start = $min;
1124
1125         for ($i = 0; $i < $this->calculated['x_axis']['num_ticks']; $i++) { // calculate x axis text sizes
1126           $value = number_format($start, $this->parameter['xDecimal'], $this->parameter['decimal_point'], $this->parameter['thousand_sep']);
1127           $this->calculated['x_axis']['data'][$i]  = $start;
1128           $this->calculated['x_axis']['text'][$i]  = $value; // text is formatted raw data
1129
1130           $size = $this->get_boundaryBox(
1131             array('points' => $axis_size,
1132                   'font'   => $axis_font,
1133                   'angle'  => $axis_angle,
1134                   'colour' => $axis_colour,
1135                   'text'   => $value));
1136           $this->calculated['x_axis']['boundary_box'][$i] = $size;
1137
1138           if ($size['height'] > $this->calculated['x_axis']['boundary_box_max']['height'])
1139             $this->calculated['x_axis']['boundary_box_max'] = $size;
1140
1141           $start += $step;
1142         }
1143       }
1144       if ($this->parameter['x_axis_text'])
1145         $this->calculated['boundary_box']['bottom'] -= $this->calculated['x_axis']['boundary_box_max']['height']
1146                                                       + $this->parameter['x_inner_padding'];
1147     }
1148
1149     // find max and min values for a data array given the resolution.
1150     function find_range($data, $min, $max, $resolution) {
1151       if (sizeof($data) == 0 ) return array('min' => 0, 'max' => 0);
1152       foreach ($data as $key => $value) {
1153         if ($value=='none') continue;
1154         if ($value > $max) $max = $value;
1155         if ($value < $min) $min = $value;
1156       }
1157
1158       if ($max == 0) {
1159         $factor = 1;
1160       } else {
1161         if ($max < 0) $factor = - pow(10, (floor(log10(abs($max))) + $resolution) );
1162         else $factor = pow(10, (floor(log10(abs($max))) - $resolution) );
1163       }
1164       if ($factor > 0.1) { // To avoid some wierd rounding errors (Moodle)
1165         $factor = round($factor * 1000.0) / 1000.0; // To avoid some wierd rounding errors (Moodle)
1166       } // To avoid some wierd rounding errors (Moodle)
1167
1168       $max = $factor * @ceil($max / $factor);
1169       $min = $factor * @floor($min / $factor);
1170
1171       //print "max=$max, min=$min<br />";
1172
1173       return array('min' => $min, 'max' => $max);
1174     }
1175
1176     public function __construct() {
1177       if (func_num_args() == 2) {
1178         $this->parameter['width']  = func_get_arg(0);
1179         $this->parameter['height'] = func_get_arg(1);
1180       }
1181       //$this->boundaryBox  = array(
1182       $this->calculated['boundary_box'] = array(
1183         'left'      =>  0,
1184         'top'       =>  0,
1185         'right'     =>  $this->parameter['width'] - 1,
1186         'bottom'    =>  $this->parameter['height'] - 1);
1187
1188       $this->init_colours();
1189
1190       //ImageColorTransparent($this->image, $this->colour['white']); // colour for transparency
1191     }
1192
1193     /**
1194      * Old syntax of class constructor. Deprecated in PHP7.
1195      *
1196      * @deprecated since Moodle 3.1
1197      */
1198     public function graph() {
1199         debugging('Use of class name as constructor is deprecated', DEBUG_DEVELOPER);
1200         self::__construct();
1201     }
1202
1203     /**
1204      * Prepare label's text for GD output.
1205      *
1206      * @param string    $label string to be prepared.
1207      * @return string   Reversed input string, if we are in RTL mode and has no numbers.
1208      *                  Otherwise, returns the string as is.
1209      */
1210     private function prepare_label_text($label) {
1211         if (right_to_left() and !preg_match('/[0-9]/i', $label)) {
1212             return core_text::strrev($label);
1213         } else {
1214             return $label;
1215         }
1216     }
1217
1218     function print_TTF($message) {
1219       $points    = $message['points'];
1220       $angle     = $message['angle'];
1221       // We have to manually reverse the label, since php GD cannot handle RTL characters properly in UTF8 strings.
1222       $text      = $this->prepare_label_text($message['text']);
1223       $colour    = $this->colour[$message['colour']];
1224       $font      = $this->parameter['path_to_fonts'].$message['font'];
1225
1226       $x         = $message['boundary_box']['x'];
1227       $y         = $message['boundary_box']['y'];
1228       $offsetX   = $message['boundary_box']['offsetX'];
1229       $offsetY   = $message['boundary_box']['offsetY'];
1230       $height    = $message['boundary_box']['height'];
1231       $width     = $message['boundary_box']['width'];
1232       $reference = $message['boundary_box']['reference'];
1233
1234       switch ($reference) {
1235         case 'top-left':
1236         case 'left-top':
1237           $y += $height - $offsetY;
1238           //$y += $offsetY;
1239           $x += $offsetX;
1240           break;
1241         case 'left-center':
1242           $y += ($height / 2) - $offsetY;
1243           $x += $offsetX;
1244           break;
1245         case 'left-bottom':
1246           $y -= $offsetY;
1247           $x += $offsetX;
1248          break;
1249         case 'top-center':
1250           $y += $height - $offsetY;
1251           $x -= ($width / 2) - $offsetX;
1252          break;
1253         case 'top-right':
1254         case 'right-top':
1255           $y += $height - $offsetY;
1256           $x -= $width  - $offsetX;
1257           break;
1258         case 'right-center':
1259           $y += ($height / 2) - $offsetY;
1260           $x -= $width  - $offsetX;
1261           break;
1262         case 'right-bottom':
1263           $y -= $offsetY;
1264           $x -= $width  - $offsetX;
1265           break;
1266         case 'bottom-center':
1267           $y -= $offsetY;
1268           $x -= ($width / 2) - $offsetX;
1269          break;
1270         default:
1271           $y = 0;
1272           $x = 0;
1273           break;
1274       }
1275       // start of Moodle addition
1276       $text = core_text::utf8_to_entities($text, true, true); //does not work with hex entities!
1277       // end of Moodle addition
1278       ImageTTFText($this->image, $points, $angle, $x, $y, $colour, $font, $text);
1279     }
1280
1281     // move boundaryBox to coordinates specified
1282     function update_boundaryBox(&$boundaryBox, $coords) {
1283       $width      = $boundaryBox['width'];
1284       $height     = $boundaryBox['height'];
1285       $x          = $coords['x'];
1286       $y          = $coords['y'];
1287       $reference  = $coords['reference'];
1288       switch ($reference) {
1289         case 'top-left':
1290         case 'left-top':
1291           $top    = $y;
1292           $bottom = $y + $height;
1293           $left   = $x;
1294           $right  = $x + $width;
1295           break;
1296         case 'left-center':
1297           $top    = $y - ($height / 2);
1298           $bottom = $y + ($height / 2);
1299           $left   = $x;
1300           $right  = $x + $width;
1301           break;
1302         case 'left-bottom':
1303           $top    = $y - $height;
1304           $bottom = $y;
1305           $left   = $x;
1306           $right  = $x + $width;
1307           break;
1308         case 'top-center':
1309           $top    = $y;
1310           $bottom = $y + $height;
1311           $left   = $x - ($width / 2);
1312           $right  = $x + ($width / 2);
1313           break;
1314         case 'right-top':
1315         case 'top-right':
1316           $top    = $y;
1317           $bottom = $y + $height;
1318           $left   = $x - $width;
1319           $right  = $x;
1320           break;
1321         case 'right-center':
1322           $top    = $y - ($height / 2);
1323           $bottom = $y + ($height / 2);
1324           $left   = $x - $width;
1325           $right  = $x;
1326           break;
1327         case 'bottom=right':
1328         case 'right-bottom':
1329           $top    = $y - $height;
1330           $bottom = $y;
1331           $left   = $x - $width;
1332           $right  = $x;
1333           break;
1334         default:
1335           $top    = 0;
1336           $bottom = $height;
1337           $left   = 0;
1338           $right  = $width;
1339           break;
1340       }
1341
1342       $boundaryBox = array_merge($boundaryBox, array('top'       => $top,
1343                                                      'bottom'    => $bottom,
1344                                                      'left'      => $left,
1345                                                      'right'     => $right,
1346                                                      'x'         => $x,
1347                                                      'y'         => $y,
1348                                                      'reference' => $reference));
1349     }
1350
1351     function get_null_size() {
1352       return array('width'      => 0,
1353                    'height'     => 0,
1354                    'offsetX'    => 0,
1355                    'offsetY'    => 0,
1356                    //'fontHeight' => 0
1357                    );
1358     }
1359
1360     function get_boundaryBox($message) {
1361       $points  = $message['points'];
1362       $angle   = $message['angle'];
1363       $font    = $this->parameter['path_to_fonts'].$message['font'];
1364       $text    = $message['text'];
1365
1366       //print ('get_boundaryBox');
1367       //expandPre($message);
1368
1369       // get font size
1370       $bounds = ImageTTFBBox($points, $angle, $font, "W");
1371       if ($angle < 0) {
1372         $fontHeight = abs($bounds[7]-$bounds[1]);
1373       } else if ($angle > 0) {
1374         $fontHeight = abs($bounds[1]-$bounds[7]);
1375       } else {
1376         $fontHeight = abs($bounds[7]-$bounds[1]);
1377       }
1378
1379       // get boundary box and offsets for printing at an angle
1380       // start of Moodle addition
1381       $text = core_text::utf8_to_entities($text, true, true); //gd does not work with hex entities!
1382       // end of Moodle addition
1383       $bounds = ImageTTFBBox($points, $angle, $font, $text);
1384
1385       if ($angle < 0) {
1386         $width = abs($bounds[4]-$bounds[0]);
1387         $height = abs($bounds[3]-$bounds[7]);
1388         $offsetY = abs($bounds[3]-$bounds[1]);
1389         $offsetX = 0;
1390
1391       } else if ($angle > 0) {
1392         $width = abs($bounds[2]-$bounds[6]);
1393         $height = abs($bounds[1]-$bounds[5]);
1394         $offsetY = 0;
1395         $offsetX = abs($bounds[0]-$bounds[6]);
1396
1397       } else {
1398         $width = abs($bounds[4]-$bounds[6]);
1399         $height = abs($bounds[7]-$bounds[1]);
1400         $offsetY = $bounds[1];
1401         $offsetX = 0;
1402       }
1403
1404       //return values
1405       return array('width'      => $width,
1406                    'height'     => $height,
1407                    'offsetX'    => $offsetX,
1408                    'offsetY'    => $offsetY,
1409                    //'fontHeight' => $fontHeight
1410                    );
1411     }
1412
1413     function draw_rectangle($border, $colour, $type) {
1414       $colour = $this->colour[$colour];
1415       switch ($type) {
1416         case 'fill':    // fill the rectangle
1417           ImageFilledRectangle($this->image, $border['left'], $border['top'], $border['right'], $border['bottom'], $colour);
1418           break;
1419         case 'box':     // all sides
1420           ImageRectangle($this->image, $border['left'], $border['top'], $border['right'], $border['bottom'], $colour);
1421           break;
1422         case 'axis':    // bottom x axis and left y axis
1423           ImageLine($this->image, $border['left'], $border['top'], $border['left'], $border['bottom'], $colour);
1424           ImageLine($this->image, $border['left'], $border['bottom'], $border['right'], $border['bottom'], $colour);
1425           break;
1426         case 'y':       // left y axis only
1427         case 'y-left':
1428           ImageLine($this->image, $border['left'], $border['top'], $border['left'], $border['bottom'], $colour);
1429           break;
1430         case 'y-right': // right y axis only
1431           ImageLine($this->image, $border['right'], $border['top'], $border['right'], $border['bottom'], $colour);
1432           break;
1433         case 'x':       // bottom x axis only
1434           ImageLine($this->image, $border['left'], $border['bottom'], $border['right'], $border['bottom'], $colour);
1435           break;
1436         case 'u':       // u shaped. bottom x axis and both left and right y axis.
1437           ImageLine($this->image, $border['left'], $border['top'], $border['left'], $border['bottom'], $colour);
1438           ImageLine($this->image, $border['right'], $border['top'], $border['right'], $border['bottom'], $colour);
1439           ImageLine($this->image, $border['left'], $border['bottom'], $border['right'], $border['bottom'], $colour);
1440           break;
1441
1442       }
1443     }
1444
1445     function init_colours() {
1446       $this->image              = ImageCreate($this->parameter['width'], $this->parameter['height']);
1447       // standard colours
1448       $this->colour['white']    = ImageColorAllocate ($this->image, 0xFF, 0xFF, 0xFF); // first colour is background colour.
1449       $this->colour['black']    = ImageColorAllocate ($this->image, 0x00, 0x00, 0x00);
1450       $this->colour['maroon']   = ImageColorAllocate ($this->image, 0x80, 0x00, 0x00);
1451       $this->colour['green']    = ImageColorAllocate ($this->image, 0x00, 0x80, 0x00);
1452       $this->colour['ltgreen']  = ImageColorAllocate ($this->image, 0x52, 0xF1, 0x7F);
1453       $this->colour['ltltgreen']= ImageColorAllocate ($this->image, 0x99, 0xFF, 0x99);
1454       $this->colour['olive']    = ImageColorAllocate ($this->image, 0x80, 0x80, 0x00);
1455       $this->colour['navy']     = ImageColorAllocate ($this->image, 0x00, 0x00, 0x80);
1456       $this->colour['purple']   = ImageColorAllocate ($this->image, 0x80, 0x00, 0x80);
1457       $this->colour['gray']     = ImageColorAllocate ($this->image, 0x80, 0x80, 0x80);
1458       $this->colour['red']      = ImageColorAllocate ($this->image, 0xFF, 0x00, 0x00);
1459       $this->colour['ltred']    = ImageColorAllocate ($this->image, 0xFF, 0x99, 0x99);
1460       $this->colour['ltltred']  = ImageColorAllocate ($this->image, 0xFF, 0xCC, 0xCC);
1461       $this->colour['orange']   = ImageColorAllocate ($this->image, 0xFF, 0x66, 0x00);
1462       $this->colour['ltorange']   = ImageColorAllocate ($this->image, 0xFF, 0x99, 0x66);
1463       $this->colour['ltltorange'] = ImageColorAllocate ($this->image, 0xFF, 0xcc, 0x99);
1464       $this->colour['lime']     = ImageColorAllocate ($this->image, 0x00, 0xFF, 0x00);
1465       $this->colour['yellow']   = ImageColorAllocate ($this->image, 0xFF, 0xFF, 0x00);
1466       $this->colour['blue']     = ImageColorAllocate ($this->image, 0x00, 0x00, 0xFF);
1467       $this->colour['ltblue']   = ImageColorAllocate ($this->image, 0x00, 0xCC, 0xFF);
1468       $this->colour['ltltblue'] = ImageColorAllocate ($this->image, 0x99, 0xFF, 0xFF);
1469       $this->colour['fuchsia']  = ImageColorAllocate ($this->image, 0xFF, 0x00, 0xFF);
1470       $this->colour['aqua']     = ImageColorAllocate ($this->image, 0x00, 0xFF, 0xFF);
1471       //$this->colour['white']    = ImageColorAllocate ($this->image, 0xFF, 0xFF, 0xFF);
1472       // shades of gray
1473       $this->colour['grayF0']   = ImageColorAllocate ($this->image, 0xF0, 0xF0, 0xF0);
1474       $this->colour['grayEE']   = ImageColorAllocate ($this->image, 0xEE, 0xEE, 0xEE);
1475       $this->colour['grayDD']   = ImageColorAllocate ($this->image, 0xDD, 0xDD, 0xDD);
1476       $this->colour['grayCC']   = ImageColorAllocate ($this->image, 0xCC, 0xCC, 0xCC);
1477       $this->colour['gray33']   = ImageColorAllocate ($this->image, 0x33, 0x33, 0x33);
1478       $this->colour['gray66']   = ImageColorAllocate ($this->image, 0x66, 0x66, 0x66);
1479       $this->colour['gray99']   = ImageColorAllocate ($this->image, 0x99, 0x99, 0x99);
1480
1481       $this->colour['none']   = 'none';
1482       return true;
1483     }
1484
1485     function output() {
1486       if ($this->debug) { // for debugging purposes.
1487         //expandPre($this->graph);
1488         //expandPre($this->y_data);
1489         //expandPre($this->x_data);
1490         //expandPre($this->parameter);
1491       } else {
1492
1493         $expiresSeconds = $this->parameter['seconds_to_live'];
1494         $expiresHours = $this->parameter['hours_to_live'];
1495
1496         if ($expiresHours || $expiresSeconds) {
1497           $now = mktime (date("H"),date("i"),date("s"),date("m"),date("d"),date("Y"));
1498           $expires = mktime (date("H")+$expiresHours,date("i"),date("s")+$expiresSeconds,date("m"),date("d"),date("Y"));
1499           $expiresGMT = gmdate('D, d M Y H:i:s', $expires).' GMT';
1500           $lastModifiedGMT  = gmdate('D, d M Y H:i:s', $now).' GMT';
1501
1502           Header('Last-modified: '.$lastModifiedGMT);
1503           Header('Expires: '.$expiresGMT);
1504         }
1505
1506         if ($this->parameter['file_name'] == 'none') {
1507           switch ($this->parameter['output_format']) {
1508             case 'GIF':
1509               Header("Content-type: image/gif");  // GIF??. switch to PNG guys!!
1510               ImageGIF($this->image);
1511               break;
1512             case 'JPEG':
1513               Header("Content-type: image/jpeg"); // JPEG for line art??. included for completeness.
1514               ImageJPEG($this->image);
1515               break;
1516            default:
1517               Header("Content-type: image/png");  // preferred output format
1518               ImagePNG($this->image);
1519               break;
1520           }
1521         } else {
1522            switch ($this->parameter['output_format']) {
1523             case 'GIF':
1524               ImageGIF($this->image, $this->parameter['file_name'].'.gif');
1525               break;
1526             case 'JPEG':
1527               ImageJPEG($this->image, $this->parameter['file_name'].'.jpg');
1528               break;
1529            default:
1530               ImagePNG($this->image, $this->parameter['file_name'].'.png');
1531               break;
1532           }
1533         }
1534
1535         ImageDestroy($this->image);
1536       }
1537     } // function output
1538
1539     function init_variable(&$variable, $value, $default) {
1540       if (!empty($value)) $variable = $value;
1541       else if (isset($default)) $variable = $default;
1542       else unset($variable);
1543     }
1544
1545     // plot a point. options include square, circle, diamond, triangle, and dot. offset is used for drawing shadows.
1546     // for diamonds and triangles the size should be an even number to get nice look. if odd the points are crooked.
1547     function plot($x, $y, $type, $size, $colour, $offset) {
1548       //print("drawing point of type: $type, at offset: $offset");
1549       $u = $x + $offset;
1550       $v = $this->calculated['inner_border']['bottom'] - $y + $offset;
1551       $half = $size / 2;
1552
1553       switch ($type) {
1554         case 'square':
1555           ImageFilledRectangle($this->image, $u-$half, $v-$half, $u+$half, $v+$half, $this->colour[$colour]);
1556           break;
1557         case 'square-open':
1558           ImageRectangle($this->image, $u-$half, $v-$half, $u+$half, $v+$half, $this->colour[$colour]);
1559           break;
1560         case 'circle':
1561           ImageArc($this->image, $u, $v, $size, $size, 0, 360, $this->colour[$colour]);
1562           ImageFillToBorder($this->image, $u, $v, $this->colour[$colour], $this->colour[$colour]);
1563           break;
1564         case 'circle-open':
1565           ImageArc($this->image, $u, $v, $size, $size, 0, 360, $this->colour[$colour]);
1566           break;
1567         case 'diamond':
1568           ImageFilledPolygon($this->image, array($u, $v-$half, $u+$half, $v, $u, $v+$half, $u-$half, $v), 4, $this->colour[$colour]);
1569           break;
1570         case 'diamond-open':
1571           ImagePolygon($this->image, array($u, $v-$half, $u+$half, $v, $u, $v+$half, $u-$half, $v), 4, $this->colour[$colour]);
1572           break;
1573         case 'triangle':
1574           ImageFilledPolygon($this->image, array($u, $v-$half, $u+$half, $v+$half, $u-$half, $v+$half), 3, $this->colour[$colour]);
1575           break;
1576         case 'triangle-open':
1577           ImagePolygon($this->image, array($u, $v-$half, $u+$half, $v+$half, $u-$half, $v+$half), 3, $this->colour[$colour]);
1578           break;
1579         case 'dot':
1580           ImageSetPixel($this->image, $u, $v, $this->colour[$colour]);
1581           break;
1582       }
1583     }
1584
1585     function bar($x, $y, $type, $size, $colour, $offset, $index, $yoffset) {
1586       $index_offset = $this->calculated['bar_offset_index'][$index];
1587       if ( $yoffset ) {
1588         $bar_offsetx = 0;
1589       } else {
1590         $bar_offsetx = $this->calculated['bar_offset_x'][$index_offset];
1591       }
1592       //$this->dbug("drawing bar at offset = $offset : index = $index: bar_offsetx = $bar_offsetx");
1593
1594       $span = ($this->calculated['bar_width'] * $size) / 2;
1595       $x_left  = $x + $bar_offsetx - $span;
1596       $x_right = $x + $bar_offsetx + $span;
1597
1598       if ($this->parameter['zero_axis'] != 'none') {
1599         $zero = $this->calculated['zero_axis'];
1600         if ($this->parameter['shadow_below_axis'] ) $zero  += $offset;
1601         $u_left  = $x_left + $offset;
1602         $u_right = $x_right + $offset - 1;
1603         $v       = $this->calculated['boundary_box']['bottom'] - $y + $offset;
1604
1605         if ($v > $zero) {
1606           $top = $zero +1;
1607           $bottom = $v;
1608         } else {
1609           $top = $v;
1610           $bottom = $zero - 1;
1611         }
1612
1613         switch ($type) {
1614           case 'open':
1615             //ImageRectangle($this->image, round($u_left), $top, round($u_right), $bottom, $this->colour[$colour]);
1616             if ($v > $zero)
1617               ImageRectangle($this->image, round($u_left), $bottom, round($u_right), $bottom, $this->colour[$colour]);
1618             else
1619               ImageRectangle($this->image, round($u_left), $top, round($u_right), $top, $this->colour[$colour]);
1620             ImageRectangle($this->image, round($u_left), $top, round($u_left), $bottom, $this->colour[$colour]);
1621             ImageRectangle($this->image, round($u_right), $top, round($u_right), $bottom, $this->colour[$colour]);
1622             break;
1623           case 'fill':
1624             ImageFilledRectangle($this->image, round($u_left), $top, round($u_right), $bottom, $this->colour[$colour]);
1625             break;
1626         }
1627
1628       } else {
1629
1630         $bottom = $this->calculated['boundary_box']['bottom'];
1631         if ($this->parameter['shadow_below_axis'] ) $bottom  += $offset;
1632         if ($this->parameter['inner_border'] != 'none') $bottom -= 1; // 1 pixel above bottom if border is to be drawn.
1633         $u_left  = $x_left + $offset;
1634         $u_right = $x_right + $offset - 1;
1635         $v       = $this->calculated['boundary_box']['bottom'] - $y + $offset;
1636
1637         // Moodle addition, plus the function parameter yoffset
1638         if ($yoffset) {                                           // Moodle
1639             $yoffset = $yoffset - round(($bottom - $v) / 2.0);    // Moodle
1640             $bottom -= $yoffset;                                  // Moodle
1641             $v      -= $yoffset;                                  // Moodle
1642         }                                                         // Moodle
1643
1644         switch ($type) {
1645           case 'open':
1646             ImageRectangle($this->image, round($u_left), $v, round($u_right), $bottom, $this->colour[$colour]);
1647             break;
1648           case 'fill':
1649             ImageFilledRectangle($this->image, round($u_left), $v, round($u_right), $bottom, $this->colour[$colour]);
1650             break;
1651         }
1652       }
1653     }
1654
1655     function area($x_start, $y_start, $x_end, $y_end, $type, $colour, $offset) {
1656       //dbug("drawing area type: $type, at offset: $offset");
1657       if ($this->parameter['zero_axis'] != 'none') {
1658         $bottom = $this->calculated['boundary_box']['bottom'];
1659         $zero   = $this->calculated['zero_axis'];
1660         if ($this->parameter['shadow_below_axis'] ) $zero  += $offset;
1661         $u_start = $x_start + $offset;
1662         $u_end   = $x_end + $offset;
1663         $v_start = $bottom - $y_start + $offset;
1664         $v_end   = $bottom - $y_end + $offset;
1665         switch ($type) {
1666           case 'fill':
1667             // draw it this way 'cos the FilledPolygon routine seems a bit buggy.
1668             ImageFilledPolygon($this->image, array($u_start, $v_start, $u_end, $v_end, $u_end, $zero, $u_start, $zero), 4, $this->colour[$colour]);
1669             ImagePolygon($this->image, array($u_start, $v_start, $u_end, $v_end, $u_end, $zero, $u_start, $zero), 4, $this->colour[$colour]);
1670            break;
1671           case 'open':
1672             //ImagePolygon($this->image, array($u_start, $v_start, $u_end, $v_end, $u_end, $zero, $u_start, $zero), 4, $this->colour[$colour]);
1673             ImageLine($this->image, $u_start, $v_start, $u_end, $v_end, $this->colour[$colour]);
1674             ImageLine($this->image, $u_start, $v_start, $u_start, $zero, $this->colour[$colour]);
1675             ImageLine($this->image, $u_end, $v_end, $u_end, $zero, $this->colour[$colour]);
1676            break;
1677         }
1678       } else {
1679         $bottom = $this->calculated['boundary_box']['bottom'];
1680         $u_start = $x_start + $offset;
1681         $u_end   = $x_end + $offset;
1682         $v_start = $bottom - $y_start + $offset;
1683         $v_end   = $bottom - $y_end + $offset;
1684
1685         if ($this->parameter['shadow_below_axis'] ) $bottom  += $offset;
1686         if ($this->parameter['inner_border'] != 'none') $bottom -= 1; // 1 pixel above bottom if border is to be drawn.
1687         switch ($type) {
1688           case 'fill':
1689             ImageFilledPolygon($this->image, array($u_start, $v_start, $u_end, $v_end, $u_end, $bottom, $u_start, $bottom), 4, $this->colour[$colour]);
1690            break;
1691           case 'open':
1692             ImagePolygon($this->image, array($u_start, $v_start, $u_end, $v_end, $u_end, $bottom, $u_start, $bottom), 4, $this->colour[$colour]);
1693            break;
1694         }
1695       }
1696     }
1697
1698     function line($x_start, $y_start, $x_end, $y_end, $type, $brush_type, $brush_size, $colour, $offset) {
1699       //dbug("drawing line of type: $type, at offset: $offset");
1700       $u_start = $x_start + $offset;
1701       $v_start = $this->calculated['boundary_box']['bottom'] - $y_start + $offset;
1702       $u_end   = $x_end + $offset;
1703       $v_end   = $this->calculated['boundary_box']['bottom'] - $y_end + $offset;
1704
1705       switch ($type) {
1706         case 'brush':
1707           $this->draw_brush_line($u_start, $v_start, $u_end, $v_end, $brush_size, $brush_type, $colour);
1708          break;
1709         case 'line' :
1710           ImageLine($this->image, $u_start, $v_start, $u_end, $v_end, $this->colour[$colour]);
1711           break;
1712         case 'dash':
1713           ImageDashedLine($this->image, $u_start, $v_start, $u_end, $v_end, $this->colour[$colour]);
1714           break;
1715       }
1716     }
1717
1718     // function to draw line. would prefer to use gdBrush but this is not supported yet.
1719     function draw_brush_line($x0, $y0, $x1, $y1, $size, $type, $colour) {
1720       //$this->dbug("line: $x0, $y0, $x1, $y1");
1721       $dy = $y1 - $y0;
1722       $dx = $x1 - $x0;
1723       $t = 0;
1724       $watchdog = 1024; // precaution to prevent infinite loops.
1725
1726       $this->draw_brush($x0, $y0, $size, $type, $colour);
1727       if (abs($dx) > abs($dy)) { // slope < 1
1728         //$this->dbug("slope < 1");
1729         $m = $dy / $dx; // compute slope
1730         $t += $y0;
1731         $dx = ($dx < 0) ? -1 : 1;
1732         $m *= $dx;
1733         while (round($x0) != round($x1)) {
1734           if (!$watchdog--) break;
1735           $x0 += $dx; // step to next x value
1736           $t += $m;   // add slope to y value
1737           $y = round($t);
1738           //$this->dbug("x0=$x0, x1=$x1, y=$y watchdog=$watchdog");
1739           $this->draw_brush($x0, $y, $size, $type, $colour);
1740
1741         }
1742       } else { // slope >= 1
1743         //$this->dbug("slope >= 1");
1744         $m = $dx / $dy; // compute slope
1745         $t += $x0;
1746         $dy = ($dy < 0) ? -1 : 1;
1747         $m *= $dy;
1748         while (round($y0) != round($y1)) {
1749           if (!$watchdog--) break;
1750           $y0 += $dy; // step to next y value
1751           $t += $m;   // add slope to x value
1752           $x = round($t);
1753           //$this->dbug("x=$x, y0=$y0, y1=$y1 watchdog=$watchdog");
1754           $this->draw_brush($x, $y0, $size, $type, $colour);
1755
1756         }
1757       }
1758     }
1759
1760     function draw_brush($x, $y, $size, $type, $colour) {
1761       $x = round($x);
1762       $y = round($y);
1763       $half = round($size / 2);
1764       switch ($type) {
1765         case 'circle':
1766           ImageArc($this->image, $x, $y, $size, $size, 0, 360, $this->colour[$colour]);
1767           ImageFillToBorder($this->image, $x, $y, $this->colour[$colour], $this->colour[$colour]);
1768           break;
1769         case 'square':
1770           ImageFilledRectangle($this->image, $x-$half, $y-$half, $x+$half, $y+$half, $this->colour[$colour]);
1771           break;
1772         case 'vertical':
1773           ImageFilledRectangle($this->image, $x, $y-$half, $x+1, $y+$half, $this->colour[$colour]);
1774           break;
1775         case 'horizontal':
1776           ImageFilledRectangle($this->image, $x-$half, $y, $x+$half, $y+1, $this->colour[$colour]);
1777           break;
1778         case 'slash':
1779           ImageFilledPolygon($this->image, array($x+$half, $y-$half,
1780                                                  $x+$half+1, $y-$half,
1781                                                  $x-$half+1, $y+$half,
1782                                                  $x-$half, $y+$half
1783                                                  ), 4, $this->colour[$colour]);
1784           break;
1785         case 'backslash':
1786           ImageFilledPolygon($this->image, array($x-$half, $y-$half,
1787                                                  $x-$half+1, $y-$half,
1788                                                  $x+$half+1, $y+$half,
1789                                                  $x+$half, $y+$half
1790                                                  ), 4, $this->colour[$colour]);
1791           break;
1792         default:
1793           @eval($type); // user can create own brush script.
1794       }
1795     }
1796
1797 } // class graph