The code is located at http://gist.github.com/429474

The code first draws the main cake rectangle. After that, it loops three times to draw the rectangles for the candlesticks, polygons for the flames, then orange circles with an alpha channel for the light. It finishes off with a series of lines whose lengths are determined by the sine function, used for the frosting.

Here’s the output.

<?php               header             ('Content'.
'-type:'.          'image/png'         );$f = 'im'.
'agecre'.          'atetrueco'.        'lor';$im=$f
(250,250);         $g='imagef'.        'illedrect'.
'angle';$g         ($im,10,120,        240,240,(630*
10000)+ 37         *100+44);for        ($i=0;$i<3;$i
++){$x=60+         $i*60;$g($im        ,$x+2,50,$x+8,
120,0xeeeeee);$h=str_rot13('vzntrsvyyrqcbyltba');$h(
$im,array($x,50,$x+5,30,$x+10,50),3,0xc00000);$h($im,
array($x+2,50,$x+ 5,40,$x+8,50),3, 0xff8000);$h ($im,
array($x+3,50,$x+5,45,$x+7,50),3,0x0000ff);$el='ima'.
'gefilledellipse';$el($im,$x+5,40,40,40,0x48ffa000);}
$l='i'.'m'.'a'. 'g'.'e'.'l'.'in'.'e';$c=0xd0d0ff; for
($i=10;$i<=240;$i++){$y=130+3* sin(($i-10)/2);$l($im,
$i,120,$i,$y,$c);}$p=strrev('egami').'png';$d='imag';
$d.='ede';$de='str';$d.=$de;$d.='oy';$p($im);$d($im);

Unobfuscated version:

<?php

header('Content-type: image/png');
$img = imageCreateTrueColor(250, 250);
imageFilledRectangle($img, 10, 120, 240, 240, 0x603000);

// loop through the 3 candles
for ($i = 0; $i < 3; $i++) {
	$x = 60 + $i * 60;
	// candlestick, red flame, orange flame, blue flame, light
	imageFilledRectangle($img, $x + 2, 50, $x + 8, 120, 0xEEEEEE);
	imageFilledPolygon($img, array($x, 50, $x + 5, 30, $x + 10, 50), 3, 0xC00000);
	imageFilledPolygon($img, array($x + 2, 50, $x + 5, 40, $x + 8, 50), 3, 0xFF8000);
	imageFilledPolygon($img, array($x + 3, 50, $x + 5, 45, $x + 7, 50), 3, 0x0000FF);
	imageFilledEllipse($img, $x + 5, 40, 40, 40, 0x48FFA000);
}

// frosting
for ($i = 10; $i <= 240; $i++) {
	$y = 130 + 3 * sin(($i - 10) / 2);
	imageLine($img, $i, 120, $i, $y, 0xD0D0FF);
}

imagePNG($img);
imageDestroy($img);

The algorithm used is very simple: Iterate through each pixel of the image, and find which reference point it is closest to. Then, set the color of the pixel to the color of the reference point.

Here’s the code.

Voronoi Diagram with 50 Colors

JS Random Line Generator

The random line generator uses the HTML5 canvas element to draw a series of connected lines, with a large variety of options. You can choose where to start drawing, the initial angle, the line lengths, how far the lines can turn left or right, the number of lines, the line colors, the line width, and the background color. In addition, if you are using a modern browser that supports canvas’s toDataURL() method, you can save the image to your computer (otherwise you’ll likely have to Print Screen it).

One nifty thing you can do with the line colors is cycle through a gradient. By using a color fade generator and selecting “show HTML codes” then the color sequence, you can copy and paste the list into the line colors box. Additionally, it accepts code in HTML (font/color, and span/style), so if somebody has a nice gradient on a website, chances are you can copy/paste the source and use it.

Here’s an example image that I created:

Random line with black-white gradient

For people with older browsers, there is a PHP version with slightly reduced functionality. It has a max color limit of 30, and no line width setting. It does allow you to turn anti-aliasing on and off, though. The source for the PHP version can be found here.

Going more in-depth, the code uses polar coordinates to draw a cardioid-like figure, which are converted into cartesian coordinates via the cfp_x() and cfp_y() functions. The new coordinates are then used in PHP’s imageFilledPolygon() function to draw the shape.

The formula to create the heart is simply done by setting the radius equal to the angle, rotated 90 degrees so that the shape is right-side up. So, at 0, the coordinates are at the origin – the sharp valley of the heart. At 180, the coordinates are at the bottom point of the heart.

View the output here.

           function                cfp_x($ox,
     $a,$d) {return ($ox+    round((cos (deg2rad($a
   ))*$d)));}function cfp_y($oy, $a, $d){return ($oy+
  round((sin(deg2rad($a)) * $d)));} $crd=array();$ct=0;
 $im=imageCreateTrueColor(250,250);$c=imageColorAllocate
 ($im,255,0,0);header("Content-type: image/png");for($i
  =-180;$i<180;$i++){$crd[]=cfp_x(125,$i -90,abs($i));
    $crd[] = cfp_y(50, $i - 90, abs($i) ); $ct++;}
        imageFilledPolygon($im, $crd,$ct,$c);
            imagePNG($im);imageDestroy
                      (($im));
                         ?>

Unobfuscated version:

function cfp_x($origin_x, $angle, $radius) {
    return $origin_x + round(cos(deg2rad($angle)) * $radius);
}
function cfp_y($origin_y, $angle, $radius) {
    return $origin_y + round(sin(deg2rad($angle)) * $radius);
}

$coords = array();
$num_pts = 0;
$img = imageCreateTrueColor(250, 250);

for ($i = -180; $i < 180; $i++) {
    $coords[] = cfp_x(125, $i - 90, abs($i));
    $coords[] = cfp_y(50, $i - 90, abs($i));
    $num_pts++;
}

imageFilledPolygon($img, $coords, $num_pts, 0xFF0000);
header('Content-type: image/png');
imagePNG($img);
imageDestroy($img);