IMAGELAYEREFFECT(3) 1 IMAGELAYEREFFECT(3)
imagelayereffect - Set the alpha blending flag to use the bundled libgd layering effects
SYNOPSIS
bool imagelayereffect (resource $image, int $effect)
DESCRIPTION
Set the alpha blending flag to use the bundled libgd layering effects.
PARAMETERS
o $
image -An image resource, returned by one of the image creation functions, such as imagecreatetruecolor(3).
o $effect
- One of the following constants:
o IMG_EFFECT_REPLACE - Use pixel replacement (equivalent of passing TRUE to imagealphablending(3))
o IMG_EFFECT_ALPHABLEND - Use normal pixel blending (equivalent of passing FALSE to imagealphablending(3))
o IMG_EFFECT_NORMAL - Same as IMG_EFFECT_ALPHABLEND.
o 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(3) 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:[NOT DISPLAYABLE MEDIA]Output of example : imagelayereffect()
NOTES
Note
This function requires GD 2.0.1 or later (2.0.28 or later is recommended).
PHP Documentation Group IMAGELAYEREFFECT(3)
