Some simple code to draw lines with specific thickness using "imagefilledpolygon". Useful if your gdlib does not support "imagesetthickness".
<?
function dickelinie($img,$start_x,$start_y,$end_x,$end_y,$color,$thickness)
{
$angle=(atan2(($start_y - $end_y),($end_x - $start_x)));
$dist_x=$thickness*(sin($angle));
$dist_y=$thickness*(cos($angle));
$p1x=ceil(($start_x + $dist_x));
$p1y=ceil(($start_y + $dist_y));
$p2x=ceil(($end_x + $dist_x));
$p2y=ceil(($end_y + $dist_y));
$p3x=ceil(($end_x - $dist_x));
$p3y=ceil(($end_y - $dist_y));
$p4x=ceil(($start_x - $dist_x));
$p4y=ceil(($start_y - $dist_y));
$array=array(0=>$p1x,$p1y,$p2x,$p2y,$p3x,$p3y,$p4x,$p4y);
imagefilledpolygon ( $img, $array, (count($array)/2), $color );
}
// Example:
header ("Content-type: image/jpeg");
$img = ImageCreate (210, 210) or die("Cannot Initialize new GD image stream ");
$backgroundcolor = ImageColorAllocate ($img, 255, 255, 255);
$orange = ImageColorAllocate($img, 252, 102, 4);
dickelinie($img, 10, 10, 10, 200,$orange,2);
dickelinie($img, 10, 200, 200, 10,$orange,2);
dickelinie($img, 200, 10, 200, 200,$orange,2);
imagejpeg($img);
ImageDestroy($img);
?>
