topical media & game development
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professional-sql-09-lib-PieChart.php / php



  <?php
  class PieChart
  {
      private center;  // center point
      private width;   // width of chart
      private image;   // image reference
  
      // initialize new object
      public function __construct(width)
      {
          // create a new image
          this->image = imagecreatetruecolor(width, width);
  
          // determine center of image
          this->center = width / 2;
          this->width = width;
  
          // fill image background white
          white = imagecolorallocate(this->image, 0xFF, 0xFF, 0xFF);
          imagefill(this->image, 0,0, white);
      }
  
      // dump image to browser or save
      public function flushImage(filename = '')
      {
          if (filename)
          {
              imagepng(this->image, filename);
          }
          else
          {
              header('Content-type: image/png');
              imagepng(this->image);
          }
      }
  
      // graph the data using the associated colors
      public function graphData(data, colors)
      {
          // allocate black for slice outline
          black = imagecolorallocate(this->image, 0x00, 0x00, 0x00);
      
          // sum of all values
          sum = array_sum(data);
      
          // starting angle of pie slice
          start = -90;
      
          for (i = 0; i < count(data); i++)
          {
              color = imagecolorallocate(this->image, colors[i]['r'],
                  colors[i]['g'], colors[i]['b']);
      
              // stop angle of pie slice
              stop = (100 * data[i] / sum * 3.6) + start;
      
              // draw arc twice - once for filled area and again for outline
              imagefilledarc(this->image, this->center, this->center,
                  this->width, this->width, start, stop, color,
                  IMG_ARC_PIE);
              imagefilledarc(this->image, this->center, this->center,
                  this->width, this->width, start, stop, black,
                  IMG_ARC_NOFILL | IMG_ARC_EDGED);
      
              // increment to next starting point
              start = stop;
          }
      }
  }
  
  data = array(150, 302, 250);
  colors = array(
      array('r' => 0x33, 'g' => 0xCC, 'b' => 0xFF),
      array('r' => 0xFF, 'g' => 0x33, 'b' => 0xCC),
      array('r' => 0xCC, 'g' => 0xFF, 'b' => 0x33));
  
  chart = new PieChart(150);
  chart->graphData(data, colors);
  chart->flushImage();
  ?>
[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

(C) Æliens 20/2/2008

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