PHP HTML Colour Chart Problem

xeonman9000 · #1 16th March 2007, 07:20 PM

Hi,
I'm trying to create a colour chart with all 16.8 million colours on it from 000000 to ffffff but I can't seem to work out what order the 6 hex-value decimals should go in to produce a smooth transition between all the colours. Here is my code.

PHP Code:


			
<html>

<head>

<title>Table Of Colours</title>

</head>

<body>

<center>

<table border="2">

<?php

for($i = 0; $i<=15; $i++){

    echo "<tr>\n";

    $hexi = base_convert($i, 10, 16);

    for($j = 0; $j<=15; $j++){

        $hexj = base_convert($j, 10, 16);

        for($k = 0; $k<=15; $k++){

            $hexk = base_convert($k, 10, 16);

            for($l = 0; $l<=15; $l++){

                $hexl = base_convert($l, 10, 16);

                for($m = 0; $m<=15; $m++){

                    $hexm = base_convert($m, 10, 16);

                    for($n = 0; $n<=15; $n++){

                        $hexn = base_convert($n, 10, 16);

                        echo "<td align=\"center\" bgcolor=\"#" . $hexi . $hexj . $hexk . $hexl . $hexm . $hexn . "\"><font color=\"#" . $hexi . $hexj . $hexk . $hexl . $hexm . $hexn . "\">#" . $hexi . $hexj . $hexk . $hexl . $hexm . $hexn . "</font></td>\n";

                    }

                }

            }

            echo "</tr>\n";

        }

    }

}

echo "</tr>\n";

?>

</table>

</center>

</body>

</html>

I thought i,j,k,l,m,n would work but it doesn't it creates little 16x16 squares of colours, the problem is, I'm not quite sure how it will look in my head, never mind when programming it.

BandC · #2 16th March 2007, 07:28 PM

Hmm, I wonder if browsers can handle a table with 16 million cells. Look at some of the color charts in graphics programs like GIMP and see where they cut off the horizontal lines. Unfortunately, I can't try your code this instant. I might be able to later.

xeonman9000 · #3 16th March 2007, 09:38 PM

Hmmm, I just ran it and I got tons of blues and greens, then it gave up. With 2Gb of RAM, I was still using 470Mb of Swap Space. maybe I'll do it with a few less colours.

BandC · #4 16th March 2007, 10:06 PM

How about instead of using table cells painting one pixel per one / many color(s) using the GD library? It may still be too much (~4000x~4000 pixels) so obviously the color chart programs are cheating by omitting many colors. Maybe you should too.

xeonman9000 · #5 16th March 2007, 11:25 PM

Hmmm, good idea, unfortunately I don't know enough PHP to do that. I'm not making this for any practical purpous, just for fun.

BandC · #6 21st March 2007, 06:50 PM

It shouldn't be that hard. Here you go:

http://www.php.net/manual/en/function.imagesetpixel.php