<?php
 
# Populate with device label, and how many rack units of space it takes up
# Two special cases... 'rackname' gets applied to the top nameplate area
# 'blankXX' append random strings or numbers to avoid a name collision in php arrays

# Example layout for a 24u rack
$rack = array (
    'rackname'    => 'IAD Rack 103', # 16 characters max for 150px nameplate
    'dns01.iad01' => 1,
    'blank23'     => 2,
    'ws1.iad01'   => 2,
    'blank12'     => 1,
    'test.iad01'  => 1,
    'blank20'     => 2,
    'other.iad01' => 4,
    'cpe01.iad01' => 2,
    'Blade Cabinet' => 9,
);
 
drawRack($rack, 'BlankRack24u.png');
 
function drawRack($r, $racktemplate)
{
    $template = imagecreatefrompng($racktemplate);
 
    # Initial offset from the top left corner to begin placing 'servers'
    $dstX = 27;
    $dstY = 22;
 
    foreach ($r as $name => $u)
    {
        # This defines the nameplate at the top of the rack
        if ($name == 'rackname')
        {
            $nameplate = imagecreate(150,20);
            $background = imagecolorallocate( $nameplate, 255, 255, 255 );
            $text_colour = imagecolorallocate( $nameplate, 0, 0, 0 );
            imageCenterString($nameplate, 5, $u, $text_colour);
            imagecopy ($template, $nameplate, 52, 1, 0, 0, 150, 20);
            continue;
        }
 
        $deviceimg = imagecreate (200, (20*$u));
        drawRackDevice(&$deviceimg,$name);
 
        imagecopy($template, $deviceimg, $dstX, $dstY, 0, 0, 200, (20*$u));
 
        $dstY += (20*$u);
        imagedestroy($deviceimg);
    }
 
    # You could also save it to a file on disk
    header( "Content-type: image/png" );
    imagepng( $template );
 
    imagedestroy($template);
}
 
function drawRackDevice ($img, $text)
{
    $background = imagecolorallocate( $img, 157, 158, 156 );
    $text_colour = imagecolorallocate( $img, 0, 0, 0 );
    $line_colour = imagecolorallocate( $img, 0, 0, 0 );
 
    # If this should be a blank space.. make a transparent 'server' to fill the gap
    if ((strlen($text) == 0) or strstr($text, 'blank'))
    {
        imagecolortransparent ($img, $background);
    } else {
 
        imageCenterString($img, 5, $text, $text_colour);
        imageline ($img, 0,0,200,0, $line_colour);
        imageline ($img, 0,imagesy($img)-1,200,imagesy($img)-1, $line_colour);
    }
}
 
# Found in comments on the php docs site
function imageCenterString(&$img, $font, $text, $color)
{
    if($font < 0 || $font > 5){ $font = 0; }
    $num = array(array(4.6, 6),
                 array(4.6, 6),
                 array(5.6, 12),
                 array(6.5, 12),
                 array(7.6, 16),
                 array(8.5, 16));
    $width = ceil(strlen($text) * $num[$font][0]);
    $x     = imagesx($img) - $width - 8;
    $y     = Imagesy($img) - ($num[$font][1] + 2);
    imagestring($img, $font, $x/2, $y/2, $text, $color);
}
 
?>