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"Creating filled polygons with PHP"

Hi. I ripped and edited this code from the PHP.net site to make a filled polygon from a set of variables posted through a form:

$values = array(
0 => $a_x, // x1
1 => $a_y, // y1
2 => $b_x, // x2
3 => $b_y, // y2
4 => $c_x, // x3
5 => $c_y, // y3
6 => $d_x, // x4
7 => $d_y, // y4
);
$im = imagecreate(500, 500);
$bg = imagecolorallocate($im, 255, 255, 255);
$blue = imagecolorallocate($im, 0, 0, 255);
imagefilledpolygon($im, $values, 4, $blue );
?>

But surprise, surprise, it doesn't work for me. I don't get any error messages though. Any ideas?

The output you showed suggests you're utilising the code incorrectly.
The snippet you posted does work, but remember you need to set

header ("Content-type: image/gif");

at the start of the php code. And of course, make sure you're calling the php script from within an image tag.

I had problems with creating images in PHP when I first had a try. Strangely, I tried running the script and it failed for no apparent reason, then I added a PHP Mail script (which I didn't use) and it worked fine.

Although that was just regular squares, so it's much simpler.

gd
GD Support - enabled
GD Version - 2.0 or higher
FreeType Support - enabled
FreeType Linkage - with freetype
GIF Read Support - enabled
GIF Create Support - enabled
JPG Support - enabled
PNG Support - enabled
WBMP Support - enabled

Yip, it's all there.

That is pretty strange. Those functions you are calling are part of the GD module for PHP, and if the web-server does not have that installed then they won't work. If you create a page that just calls and view it, that will generate a page of php status information related to the webserver. If you don't see any reference to GD there, then it's not installed and you can't use those functions.

...like this:

‰PNG  IHDR
ô
ô
ñMÉPLTEÿÿÿÿxÀ<ó
IDATx
œíÕ±mÃ0P%*Tj�¢l&�–Q,pÈ{Oæç-—_®¹||§âcü
¤ò—ˆ-“_#®‰ø[Dª€éžÏp_¿±€×ÿÛo, >Ÿç±äÛ Xâö
wžK¾­€=SGXJ¾­€2ó1Â#ÞZ@±�0ùÖâáräÛ xŒ°ÖÓÖ’
k*êü]” ÖD
åÖ)QÀV~­½ÔK§ÎžK¯]œîœz hŠ¼8
]öüW"¿œ¾ásjýR@îÙʽ{
[*?ç^ÍaÌ­? É<ÿÞ/ŸOí2S¬šÝIEND®B`‚

Very strange. I hope that big mess doesn't hold any valuable information!

Development!"

OK, it now looks like this:

$values = array(
0 => $a_x, // x1
1 => $a_y, // y1
2 => $b_x, // x2
3 => $b_y, // y2
4 => $c_x, // x3
5 => $c_y, // y3
6 => $d_x, // x4
7 => $d_y, // y4
);
$im = Imagecreate(500, 500);
$bg = ImageColorAllocate($im, 255, 255, 255);
$blue = ImageColorAllocate($im, 0, 0, 255);
ImageFilledPolygon($im, $values, 4, $blue );
ImagePng ($im);
ImageDestroy ($im);
?>

But all I get is a load of gibberish code.

By the way, the valuse for the variables come from this:

http://www.pocketmonkey.co.uk/3D_box/

It's not *true* 3D, but it gives the impresion pretty good. And it only works in IE because of the layers and stuff.

Hi. I ripped and edited this code from the PHP.net site to make a filled polygon from a set of variables posted through a form:

$values = array(
0 => $a_x, // x1
1 => $a_y, // y1
2 => $b_x, // x2
3 => $b_y, // y2
4 => $c_x, // x3
5 => $c_y, // y3
6 => $d_x, // x4
7 => $d_y, // y4
);
$im = imagecreate(500, 500);
$bg = imagecolorallocate($im, 255, 255, 255);
$blue = imagecolorallocate($im, 0, 0, 255);
imagefilledpolygon($im, $values, 4, $blue );
?>

But surprise, surprise, it doesn't work for me. I don't get any error messages though. Any ideas?