lib/graphlib.php

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