path: root/app/class/image.php

<?php

/*
 * SCROTT IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * For more information, please refer to UNLICENSE
 */

/*
 * This file defines custom image manipulation routines for Scrott.  All
 * are available in the global namespace.
 */

/*
 * Mappings from image MIME types to PHP open/write functions
 */
$_IMG_OPEN_FUNCS['image/jpeg'] = "imagecreatefromjpeg";
$_IMG_OPEN_FUNCS['image/jpg']  = "imagecreatefromjpeg";
$_IMG_OPEN_FUNCS['image/png']  = "imagecreatefrompng";

$_IMG_WRITE_FUNCS['image/jpeg'] = "imagejpeg";
$_IMG_WRITE_FUNCS['image/jpg']  = "imagejpeg";
$_IMG_WRITE_FUNCS['image/png']  = "imagepng";

/*
 * Open the given image and crop it, such that the result is a square
 * image whose side length is equal to the smaller of the original
 * dimensions and whose area is centered on the area of the original
 * image.  The resulting image is written to the same path as provided,
 * overwriting the image.
 */
function imageSquareCrop(string $uri) : bool
{
    global $_IMG_OPEN_FUNCS;
    global $_IMG_WRITE_FUNCS;

    $mime = mime_content_type($uri);
    $img = $_IMG_OPEN_FUNCS[$mime]($uri);

    if ($img === false)
        return false;

    $wid = imagesx($img);
    $hei = imagesy($img);

    $rec = array();
    $rec['width']  = min($wid, $hei);
    $rec['height'] = $rec['width'];
    $rec['y'] = ($hei / 2) - ($rec['height'] / 2);
    $rec['x'] = ($wid / 2) - ($rec['width'] / 2);

    $cropped = imagecrop($img, $rec);
    imagedestroy($img);

    if ($cropped === false)
        return false;

    $ret = $_IMG_WRITE_FUNCS[$mime]($cropped, $uri);
    imagedestroy($cropped);

    return $ret;
}

?>