PHP - Rotate image on reference point

问题

I am wondering if it is possible to rotate an image using a reference point.

For example, rotating this image by 30 degrees:

instead of having:

I would like to have:

which means rotating the image on the bottom-left point.

I would do this overlapping the rectangle to the original image if needed, and rotating it as needed only after.

回答1:

The ImageMagick extension can do this, using the DISTORTION_SCALEROTATETRANSLATE option. You might need to tweak the coordinates and angle a bit to fit your needs.

<?php
$im = new Imagick('sample.png'); 

$args = array( 
    0, // X-point
    300, // Y-point
    1,   // Scale
    -45, // Rotation
); 

$im->distortImage(Imagick::DISTORTION_SCALEROTATETRANSLATE, $args, false);

$im->setImageFormat('png');
file_put_contents('rotated.png', (string) $im);

来源：https://stackoverflow.com/questions/36603061/php-rotate-image-on-reference-point