root/trunk/RackTables/render_image.php

<?php

require 'inc/init.php';

assertStringArg ('img', 'render_image');
switch ($_REQUEST['img'])
{
    case 'minirack': // rack security context
        assertUIntArg ('rack_id', 'render_image');
        $pageno = 'rack';
        $tabno = 'default';
        fixContext();
        if (!permitted())
            renderAccessDeniedImage();
        else
            renderRackThumb ($_REQUEST['rack_id']);
        break;
    case 'progressbar': // no security context
        assertUIntArg ('done', 'render_image', TRUE);
        renderProgressBarImage ($_REQUEST['done']);
        break;
    default:
        renderError();
}

//------------------------------------------------------------------------
function renderError ()
{
    // A hardcoded value is worth of saving lots of code here.
    $img = imagecreatefrompng ('pix/error.png');
    header("Content-type: image/png");
    imagepng ($img);
    imagedestroy ($img);
}

// Having a local caching array speeds things up. A little.
function colorFromHex ($image, $hex)
{
    static $colorcache = array ();
    if (isset ($colorcache[$hex]))
        return $colorcache[$hex];
    $r = hexdec ('0x' . substr ($hex, 0, 2));
    $g = hexdec ('0x' . substr ($hex, 2, 2));
    $b = hexdec ('0x' . substr ($hex, 4, 2));
    $c = imagecolorallocate ($image, $r, $g, $b);
    $colorcache[$hex] = $c;
    return $c;
}

function renderRackThumb ($rack_id = 0)
{
    // Don't call DB extra times, hence we are most probably not the
    // only script wishing to acces the same data now.
    header("Content-type: image/png");
    $thumbcache = loadThumbCache ($rack_id);
    if ($thumbcache !== NULL)
        echo $thumbcache;
    else
    {
        ob_start();
        generateMiniRack ($rack_id);
        $capture = ob_get_contents();
        ob_end_flush();
        saveThumbCache ($rack_id, $capture);
    }
}

// Output a binary string containing the PNG minirack.
function generateMiniRack ($rack_id = 0)
{
    if (($rackData = getRackData ($rack_id, TRUE)) == NULL)
    {
        renderError();
        return;
    }
    markupObjectProblems ($rackData);
    // Cache in a local array, because we are going to use those values often.
    $rtwidth = array
    (
        0 => getConfigVar ('rtwidth_0'),
        1 => getConfigVar ('rtwidth_1'),
        2 => getConfigVar ('rtwidth_2')
    );
    $rtdepth = 9;
    $offset[0] = 3;
    $offset[1] = 3 + $rtwidth[0];
    $offset[2] = 3 + $rtwidth[0] + $rtwidth[1];
    $totalheight = 3 + 3 + $rackData['height'] * 2;
    $totalwidth = $offset[2] + $rtwidth[2] + 3;
    $img = @imagecreatetruecolor ($totalwidth, $totalheight)
        or die("Cannot Initialize new GD image stream");
    // cache our palette as well
    $color = array();
    foreach (array ('F', 'A', 'U', 'T', 'Th', 'Tw', 'Thw') as $statecode)
        $color[$statecode] = colorFromHex ($img, getConfigVar ('color_' . $statecode));
    $color['black'] = colorFromHex ($img, '000000');
    $color['gray'] = colorFromHex ($img, 'c0c0c0');
    imagerectangle ($img, 0, 0, $totalwidth - 1, $totalheight - 1, $color['black']);
    imagerectangle ($img, 1, 1, $totalwidth - 2, $totalheight - 2, $color['gray']);
    imagerectangle ($img, 2, 2, $totalwidth - 3, $totalheight - 3, $color['black']);
    for ($unit_no = 1; $unit_no <= $rackData['height']; $unit_no++)
    {
        for ($locidx = 0; $locidx < 3; $locidx++)
        {
            $colorcode = $rackData[$unit_no][$locidx]['state'];
            if (isset ($rackData[$unit_no][$locidx]['hl']))
                $colorcode = $colorcode . $rackData[$unit_no][$locidx]['hl'];
            imagerectangle
            (
                $img,
                $offset[$locidx],
                3 + ($rackData['height'] - $unit_no) * 2,
                $offset[$locidx] + $rtwidth[$locidx] - 1,
                3 + ($rackData['height'] - $unit_no) * 2 + 1,
                $color[$colorcode]
            );
        }
    }
    imagepng ($img);
    imagedestroy ($img);
}

function renderProgressBarImage ($done)
{
    $img = @imagecreatetruecolor (100, 10);
    switch (isset ($_REQUEST['theme']) ? $_REQUEST['theme'] : 'rackspace')
    {
        case 'sparenetwork':
            $color['T'] = colorFromHex ($img, '808080');
            $color['F'] = colorFromHex ($img, 'c0c0c0');
            break;
        case 'rackspace': // teal
        default:
            $color['T'] = colorFromHex ($img, getConfigVar ('color_T'));
            $color['F'] = colorFromHex ($img, getConfigVar ('color_F'));
    }
    imagefilledrectangle ($img, 0, 0, $done, 10, $color['T']);
    imagefilledrectangle ($img, $done, 0, 100, 10, $color['F']);
    header("Content-type: image/png");
    imagepng ($img);
    imagedestroy ($img);
}

function renderAccessDeniedImage ()
{
    $img = @imagecreatetruecolor (1, 1);
    imagefilledrectangle ($img, 0, 0, 1, 1, colorFromHex ($img, '000000'));
    header("Content-type: image/png");
    imagepng ($img);
    imagedestroy ($img);
}

?>