Version: 1.3
Type: Function
Category: Graphics
License: GNU General Public License
Description: This script takes a height, width start color and end color (In hex) and generates a vertical gradient jpeg using GD. The script is written so it can be called from an image tag like this:
<IMG SRC=’gradienti.php?h=400&w=600&sc=FF0000&ec=FFFF00’>
<?php
/* Version 1.3 by Warlord */
/*
Appears to be a glitch in images greater than 250px high - never reaches final colour?
*/
class grad {
var $height = 100;
var $width = 100;
var $startcol = '000000';
var $endcol = 'ffffff';
function draw() {
$im = imagecreate ($this->width, $this->height);
$b = hexdec($this->startcol);
$c = hexdec($this->endcol);
$sr = ($b & 0xFF0000) >> 16;
$sg = ($b & 0xFF00) >> 8;
$sb = ($b & 0xFF);
$er = ($c & 0xFF0000) >> 16;
$eg = ($c & 0xFF00) >> 8;
$eb = ($c & 0xFF);
$r = $er - $sr;
$g = $eg - $sg;
$b = $eb - $sb;
for ($line = 0; $line < $this->height; $line++)
{
$cRed = (($sr += ($r / $this->height)) < 0) ? (int)0: (int)$sr;
$cGreen = (($sg += ($g / $this->height)) < 0) ? (int)0: (int)$sg;
$cBlue = (($sb += ($b / $this->height)) < 0) ? (int)0: (int)$sb;
$clr[$line] = imagecolorallocate($im, $cRed, $cGreen, $cBlue);
imageline($im, 0, $line, ($this->width - 1), $line, $clr[$line]);
}
imagejpeg($im);
}
}
Header("Content-type: image/jpg");
$img = new grad;
if (isset($height)) $img->height = $height;
if (isset($width)) $img->width = $width;
if (isset($startcol)) $img->startcol = $startcol;
if (isset($endcol)) $img->endcol = $endcol;
$img->draw();
?>
