<?php

/*
***************************************************************************
Parameters :

$itemName
$itemVal
***************************************************************************
*/

function matchset($xx){
    $arrx = array_values($xx);
    $i = 0;
    while (list ($key, $val) = each ($arrx))
        {
                $xy[$i] = $val;
                $i++;
    }
    $cnt = $i;
        return $xy;
}

function PlotPie($height,$width,$diameter,$title,$itemName,$itemVal){

//initalize gd
$image = ImageCreate($width, $height);
$black = ImageColorAllocate($image, 0, 0, 0);
$white = ImageColorAllocate($image, 255, 255, 255);
ImageFill($image, 0, 0, $white);
// draw baseline
ImageLine($image, 150,150, 225, 150, $black);

// initialize some variables
$ItemNames = matchset($itemName);
$sliced = matchset($itemVal);
$sum = 0;
$degrees = Array();
$radius = $diameter/2;
$countqw = count($sliced);
$hexCode = array("255,153,0","0,204,153","204,255,102","255,102,102","102,204,255","204,153,255","255,0,0","51,0,255","255,51,153","204,0,255","255,255,51","51,255,51","255,102,0");

// calculate sum of slices
for ($x=0; $x<$countqw ; $x++)
{
        $sum += $sliced[$x];
}

// convert each slice into corresponding percentage of 360-degree circle
$degCount = 0;
for ($y=0; $y<$countqw; $y++)
{
        if((($sliced[$y]/$sum) * 360) > '0')
        {
                $degrees[$degCount] = ($sliced[$y]/$sum) * 360;
                $degCount++;
        }
}

for ($z=0; $z<$countqw; $z++)
{
        // calculate and draw arc corresponding to each slice
        ImageArc($image, 150, 150, $diameter, $diameter, $last_angle,
        ($last_angle+$degrees[$z]), $black);
        $last_angle = $last_angle+$degrees[$z];

        // calculate coordinate of end-point of each arc by obtaining
        // length of segment and adding radius
        // remember that cos() and sin() return value in radians
        // and have to be converted back to degrees!
        $end_x = round(150 + ($radius * cos($last_angle*pi()/180)));
        $end_y = round(150 + ($radius * sin($last_angle*pi()/180)));

        // demarcate slice with another line
        ImageLine($image, 150, 150, $end_x, $end_y, $black);
}

// this section is meant to calculate the mid-point of each slice
// so that it can be filled with colour

// initialize some variables
$prev_angle = 0;
$pointer = 0;

for ($z=0; $z<$countqw; $z++)
{
        // to calculate mid-point of a slice, the procedure is to use an angle
        //bisector and then obtain the mid-point of that bisector
        $pointer = $prev_angle + $degrees[$z];
        $this_angle = ($prev_angle + $pointer) / 2;
        $prev_angle = $pointer;

        // get end-point of angle bisector
        $end_x = round(150 + ($radius * cos($this_angle*pi()/180)));
        $end_y = round(150 + ($radius * sin($this_angle*pi()/180)));

        // given start point (150,150) and end-point above, mid-point can be
        // calculated with standard mid-point formula
        $mid_x = round((150+($end_x))/2);
        $mid_y = round((150+($end_y))/2);

        // depending on which slice, fill with appropriate colour
        $hexCodeSplit = explode(',',$hexCode[$z]);
        $WedgeColor = ImageColorAllocate($image, $hexCodeSplit[0],$hexCodeSplit[1],$hexCodeSplit[2]);

        ImageFillToBorder($image, $mid_x, $mid_y, $black, $WedgeColor);
}

// write string
ImageString($image,3, 10, 10, "$title", $black);

$red = ImageColorAllocate($image, 255, 153, 153);
$blue = ImageColorAllocate($image, 0, 0, 255);

// Create Color key and slice description
$adjPosition = 40;

for ($z=0; $z<$degCount; $z++)
{
        $percent = ($degrees[$z]/360)*100;
        $percent = round($percent,2);
        $adjPosition = $adjPosition + 15;
        $hexCodeSplit = explode(',',$hexCode[$z]);
        $percentLen = strlen($percent);
        if($percentLen == '4'){$percent = " "."$percent";}
        if($percentLen == '3'){$percent = "  "."$percent";}
        if($percentLen == '2'){$percent = "   "."$percent";}
        if($percentLen == '1'){$percent = "    "."$percent";}
        ImageString($image,1, 270, ($adjPosition+1), "$percent%", $black);

        $WedgeColor = ImageColorAllocate($image, $hexCodeSplit[0],$hexCodeSplit[1],$hexCodeSplit[2]);

        ImageFilledRectangle($image, 310, $adjPosition, 320, ($adjPosition+10), $black);
        ImageFilledRectangle($image, 311, ($adjPosition+1), 319, ($adjPosition+9), $WedgeColor);
        $sliceLen = strlen($sliced[$z]);
        if($sliceLen == '4'){$sliced[$z] = " "."$sliced[$z]";}
        if($sliceLen == '3'){$sliced[$z] = "  "."$sliced[$z]";}
        if($sliceLen == '2'){$sliced[$z] = "   "."$sliced[$z]";}
        if($sliceLen == '1'){$sliced[$z] = "    "."$sliced[$z]";}

        ImageString($image,1, 325, ($adjPosition+1), "$sliced[$z]", $black);
        ImageString($image,1, 375, ($adjPosition+1), "$ItemNames[$z]", $black);
}

Header("Content-type: image/png");
ImagePNG($image);
ImageDestroy($image);
}
PlotPie($height,$width,$diameter,$title,$itemName,$itemVal);
?>