gd_image_chart.inc in Charts 6

@author Mads Peter Henderson http://drupal.org/user/421971

Use GD library to draw chart on your site this is heavily inspired by http://www.phpbuilder.com/columns/wiesendanger20001218.php3?page=6 - So thanks!

File

gd_image_chart/gd_image_chart.inc

<?php

/**
 * @author Mads Peter Henderson http://drupal.org/user/421971
 * @file
 * Use GD library to draw chart on your site
 * this is heavily inspired by http://www.phpbuilder.com/columns/wiesendanger20001218.php3?page=6 - So thanks!
 */

/**
 * Implementation of hook_charts_render().
 *
 * Its a Charts module hook. It transform the data into a HTML chart.
 *
 * @param &$data
 *   Array. The
 */
function _gd_image_chart_charts_render(&$data) {
  $path = "gd_image_chart";
  $file_name = uniqid(session_id() . "_", TRUE) . ".png";
  gd_image_chart_image($data, $path, $file_name);
  return '<div><img alt="Chart created with GD Library" src="' . file_create_url($path . "/" . $file_name) . '"/></div>';
}
function gd_image_chart_image($data, $path, $file_name) {

  // create image
  $width = $data['#width'];
  $height = $data['#height'];
  $image = imagecreate($width, $height);

  // colors
  $background_color_html = empty($data['#color']['background']) ? '#FFFFFF' : $data['#color']['background'];
  $background_color_rgb = _gd_image_chart_html2rgb($background_color_html);

  //The first color to be allocated is the background!!!
  $background_color = imagecolorallocate($image, $background_color_rgb[0], $background_color_rgb[1], $background_color_rgb[2]);
  $white = imagecolorallocate($image, 0xff, 0xff, 0xff);
  $black = imagecolorallocate($image, 0x0, 0x0, 0x0);
  $gray = imagecolorallocate($image, 0xc0, 0xc0, 0xc0);
  $text_color_html = empty($data['#color']['text']) ? '#000000' : $data['#color']['text'];
  $text_color_rgb = _gd_image_chart_html2rgb($text_color_html);
  $text_color = imagecolorallocate($image, $text_color_rgb[0], $text_color_rgb[1], $text_color_rgb[2]);

  // layout
  $maxval = 0;
  $nval = 0;
  $series_count = 0;
  foreach (element_children($data) as $series) {
    $series_data = _charts_series_values($data[$series]);
    $maxval = max($series_data) > $maxval ? max($series_data) : $maxval;
    $nval = sizeof($series_data) > $nval ? sizeof($series_data) : $nval;
    $series_count += 1;
  }
  if ($data['#type'] == 'vbar2D') {

    //For vbar2d the number of x values equals max count of series times the number of series to display
    $nval = $nval * $series_count;
  }
  $vmargin = 20;

  // top (bottom) vertical margin for title (x-labels)
  $hmargin = 38;

  // left horizontal margin for y-labels
  $base = floor(($width - $hmargin) / $nval);

  // distance between columns
  $ysize = $height - 2 * $vmargin;

  // y-size of plot
  $xsize = $nval * $base;

  // x-size of plot
  // title
  $titlefont = 3;
  $title = $data['#title'];
  $txtsz = imagefontwidth($titlefont) * drupal_strlen($title);

  // pixel-width of title
  $xpos = (int) ($hmargin + ($xsize - $txtsz) / 2);

  // center the title
  $xpos = max(1, $xpos);

  // force positive coordinates
  $ypos = 3;

  // distance from top
  imagestring($image, $titlefont, $xpos, $ypos, $title, $text_color);

  // y labels and grid lines
  $labelfont = 2;
  $ngrid = 4;

  // number of grid lines
  $dydat = $maxval / $ngrid;

  // data units between grid lines
  $dypix = $ysize / ($ngrid + 1);

  // pixels between grid lines
  for ($i = 0; $i <= $ngrid + 1; $i++) {

    // iterate over y ticks
    // height of grid line in units of data
    $ydat = (int) ($i * $dydat);

    // height of grid line in pixels
    $ypos = $vmargin + $ysize - (int) ($i * $dypix);
    $txtsz = imagefontwidth($labelfont) * drupal_strlen($ydat);

    // pixel-width of label
    $txtht = imagefontheight($labelfont);

    // pixel-height of label
    $xpos = (int) (($hmargin - $txtsz) / 2);
    $xpos = max(1, $xpos);
    imagestring($image, $labelfont, $xpos, $ypos - (int) ($txtht / 2), $ydat, $text_color);
    if (!($i == 0) && !($i > $ngrid)) {

      // don't draw at Y=0 and top
      imageline($image, $hmargin - 3, $ypos, $hmargin + $xsize, $ypos, $gray);
    }
  }
  switch ($data['#type']) {
    case 'line2D':
      $yscale = $ysize / (($ngrid + 1) * $dydat);

      // pixels per data unit
      _gd_image_chart_line2d($image, $data, $series_count, $base, $padding, $vmargin, $hmargin, $ysize, $yscale, $xsize, $labelfont, $text_color);
      break;
    case 'vbar2D':
      $yscale = $ysize / (($ngrid + 1) * $dydat);

      // pixels per data unit
      _gd_image_chart_vbar2d($image, $data, $series_count, $base, $padding, $vmargin, $hmargin, $ysize, $yscale, $xsize, $labelfont, $text_color);
      break;
    default:
      return t('Type %type is not possible using %chartplugin', array(
        '%type' => $data['#type'],
        '%chartplugin' => 'GD image Chart',
      ));
  }

  // plot frame
  imagerectangle($image, $hmargin, $vmargin, $hmargin + $xsize, $vmargin + $ysize, $black);

  // write image to file system
  $directory = file_directory_path() . "/" . $path;
  if (file_check_directory($directory, TRUE)) {
    imagepng($image, $directory . "/" . $file_name);
  }
  else {
    drupal_set_message(t("Unable to cereate image at location: %directory/%filename", array(
      '%directory' => $directory,
      '%filename' => $file_name,
    )), TRUE);
  }
  imagedestroy($image);
}
function _gd_image_chart_line2d($image, $data, $series_count, $base, $padding, $vmargin, $hmargin, $ysize, $yscale, $xsize, $labelfont, $text_color) {
  $series_handled = 0;
  foreach (element_children($data) as $series) {
    $color_html = empty($data[$series]['#color']) ? '#000000' : $data[$series]['#color'];
    $color_rgb = _gd_image_chart_html2rgb($color_html);
    $color = imagecolorallocate($image, $color_rgb[0], $color_rgb[1], $color_rgb[2]);
    $series_data = _charts_series_values($data[$series]);
    $y0_pos = $vmargin + $ysize;
    $xpos_prev = FALSE;
    $ypos_prev = FALSE;
    foreach ($series_data as $xval => $yval) {
      $xpos = $hmargin + ($xval + 1) * $base - $padding;
      $ypos = $y0_pos - (int) ($yval * $yscale);
      if ($xpos_prev && $ypos_prev) {
        imageline($image, $xpos_prev, $ypos_prev, $xpos, $ypos, $color);
      }
      $xpos_prev = $xpos;
      $ypos_prev = $ypos;

      // x labels
      if ($series_handled == 0) {

        //Only print labels for first series - avoid duplicates
        if (empty($data[$series][$xval]['#label'])) {
          $value_label = '';
        }
        else {
          $value_label = $data[$series][$xval]['#label'];
        }
        $txtsz = imagefontwidth($labelfont) * drupal_strlen($value_label);
        $xpos = $xpos - $txtsz / 2;
        $ypos = $y0_pos + 3;

        // distance from x axis
        imagestring($image, $labelfont, $xpos, $ypos, $value_label, $text_color);
      }
    }
    $series_handled += 1;
  }
}
function _gd_image_chart_vbar2d($image, $data, $series_count, $base, $padding, $vmargin, $hmargin, $ysize, $yscale, $xsize, $labelfont, $text_color) {

  // columns and x labels
  $padding = 3;

  // half of spacing between columns
  $series_handled = 0;
  foreach (element_children($data) as $series) {
    $color_html = empty($data[$series]['#color']) ? '#000000' : $data[$series]['#color'];
    $color_rgb = _gd_image_chart_html2rgb($color_html);
    $color = imagecolorallocate($image, $color_rgb[0], $color_rgb[1], $color_rgb[2]);
    $series_data = _charts_series_values($data[$series]);
    foreach ($series_data as $xval => $yval) {

      // vertical columns
      $ymax = $vmargin + $ysize;
      $ymin = $ymax - (int) ($yval * $yscale);
      $xmax = $hmargin + ($xval + 1) * $base - $padding;
      $xmin = $hmargin + $xval * $base + $padding;
      $xdelta = $xmax - $xmin;
      $xmax += $xdelta * ($series_handled + ($series_count - 1) * $xval);
      $xmin += $xdelta * ($series_handled + ($series_count - 1) * $xval);
      imagefilledrectangle($image, $xmin, $ymin, $xmax, $ymax, $color);

      // x labels
      if ($series_handled == 0) {

        //Only print labels for first series - avoid duplicates
        if (empty($data[$series][$xval]['#label'])) {
          $value_label = '';
        }
        else {
          $value_label = $data[$series][$xval]['#label'];
        }
        $txtsz = imagefontwidth($labelfont) * drupal_strlen($value_label);
        $xpos = $xmin + (int) (($xdelta * $series_count - $txtsz) / 2);
        $xpos = max($xmin, $xpos);
        $ypos = $ymax + 3;

        // distance from x axis
        imagestring($image, $labelfont, $xpos, $ypos, $value_label, $text_color);
      }
    }
    $series_handled += 1;
  }
}
function _gd_image_chart_html2rgb($color) {
  if ($color[0] == '#') {
    $color = substr($color, 1);
  }
  if (strlen($color) == 6) {
    list($r, $g, $b) = array(
      $color[0] . $color[1],
      $color[2] . $color[3],
      $color[4] . $color[5],
    );
  }
  elseif (strlen($color) == 3) {
    list($r, $g, $b) = array(
      $color[0] . $color[0],
      $color[1] . $color[1],
      $color[2] . $color[2],
    );
  }
  else {
    return FALSE;
  }
  $r = hexdec($r);
  $g = hexdec($g);
  $b = hexdec($b);
  return array(
    $r,
    $g,
    $b,
  );
}

Functions

Name	Description
gd_image_chart_image
_gd_image_chart_charts_render	Implementation of hook_charts_render().
_gd_image_chart_html2rgb
_gd_image_chart_line2d
_gd_image_chart_vbar2d