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<?php

/*
*
*
* Crop from the top
*
*
*/
function my_awesome_image_resize_dimensions( $payload, $orig_w, $orig_h, $dest_w, $dest_h, $crop ){
  // Change this to a conditional that decides whether you 
  // want to override the defaults for this image or not.
  if( false )
    return $payload;
  if ( $crop ) {
    // crop the largest possible portion of the original image that we can size to $dest_w x $dest_h
    $aspect_ratio = $orig_w / $orig_h;
    $new_w = min($dest_w, $orig_w);
    $new_h = min($dest_h, $orig_h);

    if ( !$new_w ) {
      $new_w = intval($new_h * $aspect_ratio);
    }

    if ( !$new_h ) {
      $new_h = intval($new_w / $aspect_ratio);
    }

    $size_ratio = max($new_w / $orig_w, $new_h / $orig_h);

    $crop_w = round($new_w / $size_ratio);
    $crop_h = round($new_h / $size_ratio);

    $s_x = 0; // [[ formerly ]] ==> floor( ($orig_w - $crop_w) / 2 );
    $s_y = 0; // [[ formerly ]] ==> floor( ($orig_h - $crop_h) / 2 );
  } else {
    // don't crop, just resize using $dest_w x $dest_h as a maximum bounding box
    $crop_w = $orig_w;
    $crop_h = $orig_h;

    $s_x = 0;
    $s_y = 0;

    list( $new_w, $new_h ) = wp_constrain_dimensions( $orig_w, $orig_h, $dest_w, $dest_h );
  }

  // if the resulting image would be the same size or larger we don't want to resize it
  if ( $new_w >= $orig_w && $new_h >= $orig_h )
    return false;

  // the return array matches the parameters to imagecopyresampled()
  // int dst_x, int dst_y, int src_x, int src_y, int dst_w, int dst_h, int src_w, int src_h
  return array( 0, 0, (int) $s_x, (int) $s_y, (int) $new_w, (int) $new_h, (int) $crop_w, (int) $crop_h );

}
add_filter( 'image_resize_dimensions', 'my_awesome_image_resize_dimensions', 10, 6 );