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Source code

function image_resize_dimensions($orig_w, $orig_h, $dest_w, $dest_h, $crop = false) {



	if ($orig_w <= 0 || $orig_h <= 0)

		return false;

	// at least one of dest_w or dest_h must be specific

	if ($dest_w <= 0 && $dest_h <= 0)

		return false;



	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);



		$s_x = floor( ($orig_w - $crop_w) / 2 );

		$s_y = floor( ($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 );



}