PHP draws gradient color picture

Original text at: http://planetozh.com/blog/my-projects/images-php-gd-gradient-fill/ The usage example is as follows, the basic function is encapsulated in gd-gradient-fill.php , require_once(‘/path/to/gd-gradient-fill.php’); $image = new gd_gradient_fill($width,$height,$direction,$startcol

Original text at:

http://planetozh.com/blog/my-projects/images-php-gd-gradient-fill/

Usage examples are as follows , the basic functions are encapsulated in gd-gradient-fill.php,

 require_once('/path/to/gd-gradient-fill.php');
     $image = new gd_gradient_fill($width,$height,$direction,$startcolor,$endcolor,$step); 

gd_gradient_fill has 5 necessary parameters and an optional parameter:

1. integer $width
   Width of the image
2. integer $height
   Height of the image
3. string $direction
   The shape or direction of the gradient, which can be any of : vertical, horizontal, ellipse, ellipse2, circle, circle2, rectangle, diamond.
4. string $startcolor
   Gradient start color, 3 or 6 digit hexadecimal (“#ff0” or “#dd4578” )
5. string $endcolor
   Gradient end color
6. Optional : $step
   Breaks the gradient smooth blending

The following are some examples, the color gradient from #101040 to #a1a1ff, the gradient direction is different, you can see the prompt information by moving the mouse over the picture.

In addition, this function can also handle non-rectangular images.

The attached function source code is as follows:

width = $w;
 $this->height = $h;
 $this->direction = $d;
 $this->startcolor = $s;
 $this->endcolor = $e;
 $this->step = intval(abs($step));

 // Attempt to create a blank image in true colors, or a new palette based image if this fails
 if (function_exists('imagecreatetruecolor')) {
 $this->image = imagecreatetruecolor($this->width,$this->height);
 } elseif (function_exists('imagecreate')) {
 $this->image = imagecreate($this->width,$this->height);
 } else {
 die('Unable to create an image');
 }
 		
 // Fill it
 $this->fill($this->image,$this->direction,$this->startcolor,$this->endcolor);
 		
 // Show it
 $this->display($this->image);
 		
 //Return it
 return $this->image;
 }
 	
 	
 // Displays the image with a portable function that works with any file type
 // depending on your server software configuration
 function display ($im) {
 if (function_exists("imagepng")) {
 header("Content-type: image/png");
 imagepng($im);
 }
 elseif (function_exists("imagegif")) {
 header("Content-type: image/gif");
 imagegif($im);
 }
 elseif (function_exists("imagejpeg")) {
 header("Content-type: image/jpeg");
 imagejpeg($im, "", 0.5);
 }
 elseif (function_exists("imagewbmp")) {
 header("Content-type: image/vnd.wap.wbmp");
 imagewbmp($im);
 } else {
 die("Doh ! No graphical functions on this server ?");
 }
 return true;
 }
 	
 	
 // The main function that draws the gradient
 function fill($im,$direction,$start,$end) {
 		
 switch($direction) {
 case 'horizontal':
 $line_numbers = imagesx($im);
 $line_width = imagesy($im);
 list($r1,$g1,$b1) = $this->hex2rgb($start);
 list($r2,$g2,$b2) = $this->hex2rgb($end);
 break;
 case 'vertical':
 $line_numbers = imagesy($im);
 $line_width = imagesx($im);
 list($r1,$g1,$b1) = $this->hex2rgb($start);
 list($r2,$g2,$b2) = $this->hex2rgb($end);
 break;
 case 'ellipse':
 $width = imagesx($im);
 $height = imagesy($im);
 $rh=$height>$width?1:$width/$height;
 $rw=$width>$height?1:$height/$width;
 $line_numbers = min($width,$height);
 $center_x = $width/2;
 $center_y = $height/2;
 list($r1,$g1,$b1) = $this->hex2rgb($end);
 list($r2,$g2,$b2) = $this->hex2rgb($start);
 imagefill($im, 0, 0, imagecolorallocate( $im, $r1, $g1, $b1 ));
 break;
 case 'ellipse2':
 $width = imagesx($im);
 $height = imagesy($im);
 $rh=$height>$width?1:$width/$height;
 $rw=$width>$height?1:$height/$width;
 $line_numbers = sqrt(pow($width,2)+pow($height,2));
 $center_x = $width/2;
 $center_y = $height/2;
 list($r1,$g1,$b1) = $this->hex2rgb($end);
 list($r2,$g2,$b2) = $this->hex2rgb($start);
 break;
 case 'circle':
 $width = imagesx($im);
 $height = imagesy($im);
 $line_numbers = sqrt(pow($width,2)+pow($height,2));
 $center_x = $width/2;
 $center_y = $height/2;
 $rh = $rw = 1;
 list($r1,$g1,$b1) = $this->hex2rgb($end);
 list($r2,$g2,$b2) = $this->hex2rgb($start);
 break;
 case 'circle2':
 $width = imagesx($im);
 $height = imagesy($im);
 $line_numbers = min($width,$height);
 $center_x = $width/2;
 $center_y = $height/2;
 $rh = $rw = 1;
 list($r1,$g1,$b1) = $this->hex2rgb($end);
 list($r2,$g2,$b2) = $this->hex2rgb($start);
 imagefill($im, 0, 0, imagecolorallocate( $im, $r1, $g1, $b1 ));
 break;
 case 'square':
 case 'rectangle':
 $width = imagesx($im);
 $height = imagesy($im);
 $line_numbers = max($width,$height)/2;
 list($r1,$g1,$b1) = $this->hex2rgb($end);
 list($r2,$g2,$b2) = $this->hex2rgb($start);
 break;
 case 'diamond':
 list($r1,$g1,$b1) = $this->hex2rgb($end);
 list($r2,$g2,$b2) = $this->hex2rgb($start);
 $width = imagesx($im);
 $height = imagesy($im);
 $rh=$height>$width?1:$width/$height;
 $rw=$width>$height?1:$height/$width;
 $line_numbers = min($width,$height);
 break;
 default:
 }
 		
 for ( $i = 0; $i step ) {
 // old values:
 $old_r=$r;
 $old_g=$g;
 $old_b=$b;
 // new values:
 $r = ( $r2 - $r1 != 0 ) ? intval( $r1 + ( $r2 - $r1 ) * ( $i / $line_numbers ) ): $r1;
 $g = ( $g2 - $g1 != 0 ) ? intval( $g1 + ( $g2 - $g1 ) * ( $i / $line_numbers ) ): $g1;
 $b = ( $b2 - $b1 != 0 ) ? intval( $b1 + ( $b2 - $b1 ) * ( $i / $line_numbers ) ): $b1;
 // if new values ​​are really new ones, allocate a new color, otherwise reuse previous color.
 // There's a "feature" in imagecolorallocate that makes this function
 // always returns '-1' after 255 colors have been allocated in an image that was created with
 // imagecreate (everything works fine with imagecreatetruecolor)
 if ( "$old_r,$old_g,$old_b" != "$r,$g,$b")
 $fill = imagecolorallocate( $im, $r, $g, $b );
 switch($direction) {
 case 'vertical':
 imagefilledrectangle($im, 0, $i, $line_width, $i+$this->step, $fill);
 break;
 case 'horizontal':
 imagefilledrectangle( $im, $i, 0, $i+$this->step, $line_width, $fill );
 break;
 case 'ellipse':
 case 'ellipse2':
 case 'circle':
 case 'circle2':
 imagefilledellipse ($im,$center_x, $center_y, ($line_numbers-$i)*$rh, ($line_numbers-$i)*$rw,$fill);
 break;
 case 'square':
 case 'rectangle':
 imagefilledrectangle ($im,$i*$width/$height,$i*$height/$width,$width-($i*$width/$height), $height-($i*$height/$width)  ,$fill);
 break;
 case 'diamond':
 imagefilledpolygon($im, array (
 $width/2, $i*$rw-0.5*$height,
 $i*$rh-0.5*$width, $height/2,
 $width/2,1.5*$height-$i*$rw,
 1.5*$width-$i*$rh, $height/2 ), 4, $fill);
 break;
 default:
 }
 }
 }
 	
 // #ff00ff -> array(255,0,255) or #f0f -> array(255,0,255)
 function hex2rgb($color) {
 $color = str_replace('#','',$color);
 $s = strlen($color) / 3;
 $rgb[]=hexdec(str_repeat(substr($color,0,$s),2/$s));
 $rgb[]=hexdec(str_repeat(substr($color,$s,$s),2/$s));
 $rgb[]=hexdec(str_repeat(substr($color,2*$s,$s),2/$s));
 return $rgb;
 }
 }
 ?>
 

iefreer
rray(255,0,255)
function hex2rgb($color) {
$color = str_replace(‘#’,”,$color);
$s = strlen($color) / 3;
$rgb[]=hexdec(str_repeat(substr($color,0,$s),2/$s));
$rgb[]=hexdec(str_repeat(substr($color,$s,$s),2/$s));
$rgb[]=hexdec(str_repeat(substr($color,2*$s,$s),2/$s));
return $rgb;
}
}
?>

iefreer