imagelayereffect

(PHP 4 >= 4.3.0, PHP 5)

imagelayereffect — Set the alpha blending flag to use the bundled libgd layering effects

Description

bool imagelayereffect ( resource $image , int $effect )

Set the alpha blending flag to use the bundled libgd layering effects.

Parameters

image

An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().

effect

One of the following constants:

IMG_EFFECT_REPLACE

Use pixel replacement (equivalent of passing TRUE to imagealphablending())

IMG_EFFECT_ALPHABLEND

Use normal pixel blending (equivalent of passing FALSE to imagealphablending())

IMG_EFFECT_NORMAL

Same as IMG_EFFECT_ALPHABLEND.

IMG_EFFECT_OVERLAY

Overlay has the effect that black background pixels will remain black, white background pixels will remain white, but grey background pixels will take the colour of the foreground pixel.

Return Values

Returns TRUE on success or FALSE on failure.

Examples

Example #1 imagelayereffect() example

<?php
// Setup an image
$im = imagecreatetruecolor(100, 100);

// Set a background
imagefilledrectangle($im, 0, 0, 100, 100, imagecolorallocate($im, 220, 220, 220));

// Apply the overlay alpha blending flag
imagelayereffect($im, IMG_EFFECT_OVERLAY);

// Draw two grey ellipses
imagefilledellipse($im, 50, 50, 40, 40, imagecolorallocate($im, 100, 255, 100));
imagefilledellipse($im, 50, 50, 50, 80, imagecolorallocate($im, 100, 100, 255));
imagefilledellipse($im, 50, 50, 80, 50, imagecolorallocate($im, 255, 100, 100));

// Output
header('Content-type: image/png');

imagepng($im);
imagedestroy($im);
?>

The above example will output something similar to:

Notes

Note: This function is only available if PHP is compiled with the bundled version of the GD library.

Note: This function requires GD 2.0.1 or later (2.0.28 or later is recommended).