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).