note 93920 added to function.imagefill

Here is a function to generate a gradient. You specify width, heigth and 4 colors (of the 4 corners). An image handle of the gradient image will be returned. You can copy the returned image onto another image using imageecopy. This can be helpful if you want to generate a shadow for example. ("Glow effect example": Generate 8 gradients, one for each side and one for each corner. The outer side of the gradients have the background color and the inner sides have a bright color such as white.) But beware: This function is not optimized for performance, it might become slow on big images. For shadows, better cache the generated gradients. Note: For gradients, using true-color is highly recommended. <?php function gradient($w=100, $h=100, $c=array('#FFFFFF','#FF0000','#00FF00','#0000FF'), $hex=true) { /* Generates a gradient image Author: Christopher Kramer Parameters: w: width in px h: height in px c: color-array with 4 elements: $c[0]: top left color $c[1]: top right color $c[2]: bottom left color $c[3]: bottom right color if $hex is true (default), colors are hex-strings like '#FFFFFF' (NOT '#FFF') if $hex is false, a color is an array of 3 elements which are the rgb-values, e.g.: $c[0]=array(0,255,255); */ $im=imagecreatetruecolor($w,$h); if($hex) { // convert hex-values to rgb for($i=0;$i<=3;$i++) { $c[$i]=hex2rgb($c[$i]); } } $rgb=$c[0]; // start with top left color for($x=0;$x<=$w;$x++) { // loop columns for($y=0;$y<=$h;$y++) { // loop rows // set pixel color $col=imagecolorallocate($im,$rgb[0],$rgb[1],$rgb[2]); imagesetpixel($im,$x-1,$y-1,$col); // calculate new color for($i=0;$i<=2;$i++) { $rgb[$i]= $c[0][$i]*(($w-$x)*($h-$y)/($w*$h)) + $c[1][$i]*($x *($h-$y)/($w*$h)) + $c[2][$i]*(($w-$x)*$y /($w*$h)) + $c[3][$i]*($x *$y /($w*$h)); } } } return $im; } function hex2rgb($hex) { $rgb[0]=hexdec(substr($hex,1,2)); $rgb[1]=hexdec(substr($hex,3,2)); $rgb[2]=hexdec(substr($hex,5,2)); return($rgb); } // usage example $image=gradient(300, 300, array('#000000', '#FFFFFF', '#FF0000', '#0000FF')); header('Content-type: image/png'); imagepng($image); imagedestroy($image); ?> ---- Server IP: 85.214.154.209 Probable Submitter: 77.23.19.136 ---- Manual Page -- http://www.php.net/manual/en/function.imagefill.php Edit -- https://master.php.net/note/edit/93920 Del: integrated -- https://master.php.net/note/delete/93920/integrated Del: useless -- https://master.php.net/note/delete/93920/useless Del: bad code -- https://master.php.net/note/delete/93920/bad+code Del: spam -- https://master.php.net/note/delete/93920/spam Del: non-english -- https://master.php.net/note/delete/93920/non-english Del: in docs -- https://master.php.net/note/delete/93920/in+docs Del: other reasons-- https://master.php.net/note/delete/93920 Reject -- https://master.php.net/note/reject/93920 Search -- https://master.php.net/manage/user-notes.php