Source

File: wp-admin/includes/image-edit.php

function image_edit_apply_changes( $image, $changes ) {
	if ( is_resource( $image ) ) {
		/* translators: 1: $image, 2: WP_Image_Editor */
		_deprecated_argument( __FUNCTION__, '3.5.0', sprintf( __( '%1$s needs to be a %2$s object.' ), '$image', 'WP_Image_Editor' ) );
	}

	if ( ! is_array( $changes ) ) {
		return $image;
	}

	// Expand change operations.
	foreach ( $changes as $key => $obj ) {
		if ( isset( $obj->r ) ) {
			$obj->type  = 'rotate';
			$obj->angle = $obj->r;
			unset( $obj->r );
		} elseif ( isset( $obj->f ) ) {
			$obj->type = 'flip';
			$obj->axis = $obj->f;
			unset( $obj->f );
		} elseif ( isset( $obj->c ) ) {
			$obj->type = 'crop';
			$obj->sel  = $obj->c;
			unset( $obj->c );
		}
		$changes[ $key ] = $obj;
	}

	// Combine operations.
	if ( count( $changes ) > 1 ) {
		$filtered = array( $changes[0] );
		for ( $i = 0, $j = 1, $c = count( $changes ); $j < $c; $j++ ) {
			$combined = false;
			if ( $filtered[ $i ]->type == $changes[ $j ]->type ) {
				switch ( $filtered[ $i ]->type ) {
					case 'rotate':
						$filtered[ $i ]->angle += $changes[ $j ]->angle;
						$combined               = true;
						break;
					case 'flip':
						$filtered[ $i ]->axis ^= $changes[ $j ]->axis;
						$combined              = true;
						break;
				}
			}
			if ( ! $combined ) {
				$filtered[ ++$i ] = $changes[ $j ];
			}
		}
		$changes = $filtered;
		unset( $filtered );
	}

	// Image resource before applying the changes.
	if ( $image instanceof WP_Image_Editor ) {

		/**
		 * Filters the WP_Image_Editor instance before applying changes to the image.
		 *
		 * @since 3.5.0
		 *
		 * @param WP_Image_Editor $image   WP_Image_Editor instance.
		 * @param array           $changes Array of change operations.
		 */
		$image = apply_filters( 'wp_image_editor_before_change', $image, $changes );
	} elseif ( is_resource( $image ) ) {

		/**
		 * Filters the GD image resource before applying changes to the image.
		 *
		 * @since 2.9.0
		 * @deprecated 3.5.0 Use {@see 'wp_image_editor_before_change'} instead.
		 *
		 * @param resource $image   GD image resource.
		 * @param array    $changes Array of change operations.
		 */
		$image = apply_filters_deprecated( 'image_edit_before_change', array( $image, $changes ), '3.5.0', 'wp_image_editor_before_change' );
	}

	foreach ( $changes as $operation ) {
		switch ( $operation->type ) {
			case 'rotate':
				if ( 0 != $operation->angle ) {
					if ( $image instanceof WP_Image_Editor ) {
						$image->rotate( $operation->angle );
					} else {
						$image = _rotate_image_resource( $image, $operation->angle );
					}
				}
				break;
			case 'flip':
				if ( 0 != $operation->axis ) {
					if ( $image instanceof WP_Image_Editor ) {
						$image->flip( ( $operation->axis & 1 ) != 0, ( $operation->axis & 2 ) != 0 );
					} else {
						$image = _flip_image_resource( $image, ( $operation->axis & 1 ) != 0, ( $operation->axis & 2 ) != 0 );
					}
				}
				break;
			case 'crop':
				$sel = $operation->sel;

				if ( $image instanceof WP_Image_Editor ) {
					$size = $image->get_size();
					$w    = $size['width'];
					$h    = $size['height'];

					$scale = 1 / _image_get_preview_ratio( $w, $h ); // Discard preview scaling.
					$image->crop( $sel->x * $scale, $sel->y * $scale, $sel->w * $scale, $sel->h * $scale );
				} else {
					$scale = 1 / _image_get_preview_ratio( imagesx( $image ), imagesy( $image ) ); // Discard preview scaling.
					$image = _crop_image_resource( $image, $sel->x * $scale, $sel->y * $scale, $sel->w * $scale, $sel->h * $scale );
				}
				break;
		}
	}

	return $image;
}