a PHP function to obtain a darker HTML colour code
I needed a PHP function to return me a darker HTML colour code. I couldn't find one, therefore I wrote one. So here's a PHP code that randomly creates some HTML colour codes and applies the darkifier function. Here comes the source:
<?php
#
# filename: darkifier.php
# descr: randomly generate 100 html color codes, then apply the darkerHtmlColor function
# author: calin uioreanu http://php9.bloghi.com
#
# generate 100 random colors
for ($count=0; $count<30; $count++) {
$PlotColors[] = '#'. sprintf("%06X", rand(0,pow(16,6)));
}
echo
'<table border="1">';
foreach ($PlotColors as $htmlColor) {
$darkerColor = darkerHtmlColor($htmlColor);
echo
'<tr>',
'<td>darkerHtmlColor(</td>',
'<td style="background-color:'. $htmlColor .'">', "n",
$htmlColor,
'</td>',
'<td>)=</td>',
'<td style="background-color:'. $darkerColor .'">', "n",
$darkerColor,
'</td>',
'</tr>',
'';
}
echo
'</table>';
/**
html-color-code darkerHtmlColor(html-color-code)
returns a "darker" version of the HTML color code provided.
*/
function darkerHtmlColor($htmlColor)
{
# input patch
if (substr($htmlColor, 0, 1) == '#') {
$htmlColor = substr($htmlColor, 1);
}
# input check
if (strlen($htmlColor)!=6) {
die (print 'darkerHtmlColor:: invalid parameter: '. $htmlColor);
}
# str_split (php5)
$pieces = explode(' ', rtrim(chunk_split($htmlColor, 2, ' ')));
foreach ($pieces as $piece) {
# convert from base16 to base10, reduce the brightness then come back to base16
$darkpiece = (int) (base_convert($piece, 16, 10) / 2);
$darkerColor .= sprintf("%02x", $darkpiece);
}
return '#'. $darkerColor;
} // end func
?>
And here's some output:
| darkerHtmlColor( | #13B540 | )= | #095a20 |
| darkerHtmlColor( | #DF1AE8 | )= | #6f0d74 |
| darkerHtmlColor( | #294287 | )= | #142143 |
| darkerHtmlColor( | #33E807 | )= | #197403 |
| darkerHtmlColor( | #96E440 | )= | #4b7220 |
| darkerHtmlColor( | #0E6DB2 | )= | #073659 |
| darkerHtmlColor( | #C0350D | )= | #601a06 |
| darkerHtmlColor( | #1B9C73 | )= | #0d4e39 |
| darkerHtmlColor( | #DB3AC7 | )= | #6d1d63 |
| darkerHtmlColor( | #5288D7 | )= | #29446b |
| darkerHtmlColor( | #54528F | )= | #2a2947 |
| darkerHtmlColor( | #E34C05 | )= | #712602 |
| darkerHtmlColor( | #A60BA1 | )= | #530550 |
| darkerHtmlColor( | #B5B483 | )= | #5a5a41 |
| darkerHtmlColor( | #FCAC1F | )= | #7e560f |
| darkerHtmlColor( | #93B616 | )= | #495b0b |
| darkerHtmlColor( | #53E9DD | )= | #29746e |
| darkerHtmlColor( | #1234D4 | )= | #091a6a |
| darkerHtmlColor( | #6DE2A5 | )= | #367152 |
| darkerHtmlColor( | #39BBE0 | )= | #1c5d70 |
| darkerHtmlColor( | #316EA2 | )= | #183751 |
| darkerHtmlColor( | #8C847E | )= | #46423f |
| darkerHtmlColor( | #63E4AC | )= | #317256 |
| darkerHtmlColor( | #AEEA2D | )= | #577516 |
| darkerHtmlColor( | #90BB41 | )= | #485d20 |
| darkerHtmlColor( | #91C9BA | )= | #48645d |
| darkerHtmlColor( | #DF4F12 | )= | #6f2709 |
| darkerHtmlColor( | #27CCFE | )= | #13667f |
| darkerHtmlColor( | #5744A1 | )= | #2b2250 |
| darkerHtmlColor( | #5FF19F | )= | #2f784f |
I'd like to know you found this useful.
