Labeled 3D Pie Chart with GD

This GD example program demonstrates the code for an example program that demonstrates how to draw a labeled 3D pie chart with GD and create a png image.

LabeledPieChart3D.php

<?php
  class CPieChart3D {
    private static $saaiColors = null;
    public static function GetColorArray() {
      if (self::$saaiColors == null) {
        self::$saaiColors = array(
          array(250, 100, 120),
          array(100, 120, 250),
          array(150, 100, 240),
          array(200, 150, 100),
          array(190, 150, 200),
          array(60, 128, 128),
          array(160, 40, 60),
          array(100, 180, 60),
          array(40, 70, 90),
          array(220, 110, 60),
          array(80, 70, 60)
        );
      }
      shuffle(self::$saaiColors);
      return self::$saaiColors;
    }
    var $mdacData = null;
    var $miGraphWidth;
    var $miGraphHeight;
    var $miGraphDepth;
    var $miSliceOffset;
    var $mdCenterX;
    var $mdCenterY;
    var $mqFont = null;
    public $mqImage = null;

    function __construct() {
      $this->miGraphWidth = 400;
      $this->miGraphHeight = 300;
      $this->miGraphDepth = 25;
      $this->miSliceOffset = 10;
      $iImageWidth = $this->miGraphWidth + 2*$this->miSliceOffset + 180;
      $iImageHeight = $this->miGraphHeight + $this->miGraphDepth + 3*$this->miSliceOffset;
      $this->mqImage = imagecreate($iImageWidth, $iImageHeight);
      // Allocate while to color the background
      imagecolorallocate($this->mqImage, 255, 255, 255);
      $this->mdCenterX = ($this->miGraphWidth + 3*$this->miSliceOffset)/2;
      $this->mdCenterY = ($this->miGraphHeight + 3*$this->miSliceOffset)/2;
      $this->mdacData = array();
      $this->mqFont = "./verdana.ttf";
    }

    public function AddData($sKey, $dValue) {
      $this->mdacData[$sKey] = $dValue;
    }

    public function Draw($dStartAngle = 0) {
      $qColors = self::GetColorArray();
      $saKeys = array_keys($this->mdacData);
      $iaValues = array_values($this->mdacData);
      $iValueSum = array_sum($iaValues);
      $iDataCount = count($this->mdacData);
      $qGraphColors = array();
      $qShadowColors = array();
      $qaArcVectorX = array();
      $qaArcVectorY = array();
      $dPriorAngle = $dStartAngle;
      $dCurrentAngle = 0;
      for($i = 0; $i < $iDataCount; $i++){
        $dAngleOffset = (($iaValues[$i] / $iValueSum) * 360);
        $dCurrentAngle = $dPriorAngle + $dAngleOffset;
        $qGraphColors[$i] = imagecolorallocate($this->mqImage,
          $qColors[$i][0], $qColors[$i][1], $qColors[$i][2]);
        $qShadowColors[$i] = imagecolorallocate($this->mqImage,
          ($qColors[$i][0] / 1.5), ($qColors[$i][1] / 1.5), ($qColors[$i][2] / 1.5));
        $qaArcVectorX[$i] = cos(deg2rad(($dPriorAngle + $dCurrentAngle) / 2));
        $qaArcVectorY[$i] = sin(deg2rad(($dPriorAngle + $dCurrentAngle) / 2));
        $dPriorAngle = $dCurrentAngle;
      }
      // Fill in the shadow below the graph
      for($z = 1; $z <= $this->miGraphDepth; $z++){
        // Draw an arc at each depth
        $dPriorAngle = $dStartAngle;
        for($i = 0; $i < $iDataCount; $i++){
          $dAngleOffset = (($iaValues[$i] / $iValueSum) * 360);
          $dCurrentAngle = $dPriorAngle + $dAngleOffset;
          $dArcCenterX = $this->mdCenterX + ($qaArcVectorX[$i] * $this->miSliceOffset);
          $dArcCenterY = $this->mdCenterY + ($qaArcVectorY[$i] * $this->miSliceOffset)
            + $this->miGraphDepth - $z;
          imagefilledarc($this->mqImage, $dArcCenterX, $dArcCenterY,
            $this->miGraphWidth, $this->miGraphHeight, $dPriorAngle, $dCurrentAngle,
            $qShadowColors[$i], IMG_ARC_PIE);
          $dPriorAngle = $dCurrentAngle;
        }
      }
      $iKeySize = 10;
      $iKeySpace = 40;
      $iKeyOffset = ($this->miGraphWidth+2*$iDelta) + $iKeySpace;
      // Draw the top, the labels and the key
      $qGraphTextColor = imagecolorallocate($this->mqImage, 200, 200, 200);
      $qKeyTextColor = imagecolorallocate($this->mqImage, 64, 64, 64);
      for($i = 0; $i < $iDataCount; $i++){
        $dAngleOffset = (($iaValues[$i] / $iValueSum) * 360);
        $dCurrentAngle = $dPriorAngle + $dAngleOffset;
        $dArcCenterX = $this->mdCenterX + ($qaArcVectorX[$i] * $this->miSliceOffset);
        $dArcCenterY = $this->mdCenterY + ($qaArcVectorY[$i] * $this->miSliceOffset);
        imagefilledarc($this->mqImage, $dArcCenterX, $dArcCenterY,
          $this->miGraphWidth, $this->miGraphHeight, $dPriorAngle, $dCurrentAngle,
          $qGraphColors[$i], IMG_ARC_PIE);
        $dGraphTextX = $this->mdCenterX + ($qaArcVectorX[$i] * ($this->miGraphWidth / 3))
          - $iKeySize;
        $dGraphTextY = $this->mdCenterY + ($qaArcVectorY[$i] * ($this->miGraphHeight / 3))
          + $iKeySize/3;
        imagettftext($this->mqImage, 2*$iKeySize/3, 0, $dGraphTextX, $dGraphTextY,
          $qGraphTextColor, $this->mqFont, $iaValues[$i]);
        // Key Color Squares
        imagefilledrectangle($this->mqImage, $iKeyOffset, $iKeySize + ($i * $iKeySize * 2),
          $iKeyOffset + $iKeySize, (($i + 1) * $iKeySize * 2), $qGraphColors[$i]);
        // Key Text
        imagettftext($this->mqImage, $iKeySize, 0, $iKeyOffset + (1.4*$iKeySize),
          (($i + 1) * $iKeySize * 2), $qKeyTextColor, $this->mqFont, $saKeys[$i]);
        $dPriorAngle = $dCurrentAngle;
      }
    }
  }

  $qPieChart = new CPieChart3D;
  $qPieChart->AddData('Catholic', 1200);
  $qPieChart->AddData("Eastern Orthodox", 210);
  $qPieChart->AddData("Oriental Orthodox", 75);
  $qPieChart->AddData("Protestant", 750);
  $qPieChart->AddData("Other", 27);
  $qPieChart->Draw();

  header('Content-type: image/png');
  imagepng($qPieChart->mqImage);
  imagedestroy($qPieChart->mqImage);
?>

Output