Importing Pixel Bender kernels - chung-leong/qb GitHub Wiki
The @import tag directs QB to import a Pixel Bender kernel into a function:
<?php
/**
* @engine qb
* @import pbj/sepia.pbj
*
* @param image $dst
* @param image $src
* @param float32 $intensity
*/
function sepia_filter(&$dst, $src, $intensity) {
}
qb_compile();
?>In the example above, the instructions contained in sepia.pbj are imported into the function sepia_filter(). Afterward, this function can be used elsewhere to apply the sepia effect on an image:
<?php
$image = imagecreatefrompng("images/malgorzata_socha.png");
$output = imagecreatetruecolor(imagesx($image), imagesy($image));
sepia_filter($output, $image, 0.2);
header("Content-type: image/jpeg");
imagejpeg($output);
?>You can use qb_extract() to obtain the function declaration for a given PBJ file:
<?php
echo qb_extract("pbj/sepia.pbj", QB_PBJ_DECLARATION);
?>The example code above will produce the following:
/**
* Sepia() a variable sepia filter (Adobe Systems)
*
* @engine qb
* @import pbj/sepia.pbj
*
* @param image $dst
* @param image $src
* @param float32 $intensity
*
* @return void
*/
function Sepia(&$dst, $src, $intensity) {}