imagelayereffect
(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)
imagelayereffect — 设定 alpha 混色标志以使用绑定的 libgd 分层效果
说明
imagelayereffect
( resource
$image
, int $effect
) : bool设定 alpha 混色标志以使用绑定的 libgd 分层效果。
参数
-
image -
由图象创建函数(例如imagecreatetruecolor())返回的图象资源。
-
effect -
One of the following constants:
-
IMG_EFFECT_REPLACE -
Use pixel replacement (equivalent of passing
trueto imagealphablending()) -
IMG_EFFECT_ALPHABLEND -
Use normal pixel blending (equivalent of passing
falseto 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.
-
返回值
成功时返回 true， 或者在失败时返回 false。
范例
示例 #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);
?>
以上例程的输出类似于：
