<?php

/**

 * WordPress API for media display.

 *

 * @package WordPress

 * @subpackage Media

 */

/**

 * Scale down the default size of an image.

 *

 * This is so that the image is a better fit for the editor and theme.

 *

 * The $size parameter accepts either an array or a string. The supported string

 * values are 'thumb' or 'thumbnail' for the given thumbnail size or defaults at

 * 128 width and 96 height in pixels. Also supported for the string value is

 * 'medium' and 'full'. The 'full' isn't actually supported, but any value other

 * than the supported will result in the content_width size or 500 if that is

 * not set.

 *

 * Finally, there is a filter named 'editor_max_image_size', that will be called

 * on the calculated array for width and height, respectively. The second

 * parameter will be the value that was in the $size parameter. The returned

 * type for the hook is an array with the width as the first element and the

 * height as the second element.

 *

 * @since 2.5.0

 * @uses wp_constrain_dimensions() This function passes the widths and the heights.

 *

 * @param int $width Width of the image

 * @param int $height Height of the image

 * @param string|array $size Size of what the result image should be.

 * @param context Could be 'display' (like in a theme) or 'edit' (like inserting into an editor)

 * @return array Width and height of what the result image should resize to.

 */

function image_constrain_size_for_editor($width, $height, $size = 'medium', $context = null ) {

	global $content_width, $_wp_additional_image_sizes;

	if ( ! $context )

		$context = is_admin() ? 'edit' : 'display';

	if ( is_array($size) ) {

		$max_width = $size[0];

		$max_height = $size[1];

	}

	elseif ( $size == 'thumb' || $size == 'thumbnail' ) {

		$max_width = intval(get_option('thumbnail_size_w'));

		$max_height = intval(get_option('thumbnail_size_h'));

		// last chance thumbnail size defaults

		if ( !$max_width && !$max_height ) {

			$max_width = 128;

			$max_height = 96;

		}

	}

	elseif ( $size == 'medium' ) {

		$max_width = intval(get_option('medium_size_w'));

		$max_height = intval(get_option('medium_size_h'));

		// if no width is set, default to the theme content width if available

	}

	elseif ( $size == 'large' ) {

		// We're inserting a large size image into the editor. If it's a really

		// big image we'll scale it down to fit reasonably within the editor

		// itself, and within the theme's content width if it's known. The user

		// can resize it in the editor if they wish.

		$max_width = intval(get_option('large_size_w'));

		$max_height = intval(get_option('large_size_h'));

		if ( intval($content_width) > 0 )

			$max_width = min( intval($content_width), $max_width );

	} elseif ( isset( $_wp_additional_image_sizes ) && count( $_wp_additional_image_sizes ) && in_array( $size, array_keys( $_wp_additional_image_sizes ) ) ) {

		$max_width = intval( $_wp_additional_image_sizes[$size]['width'] );

		$max_height = intval( $_wp_additional_image_sizes[$size]['height'] );

		if ( intval($content_width) > 0 && 'edit' == $context ) // Only in admin. Assume that theme authors know what they're doing.

			$max_width = min( intval($content_width), $max_width );

	}

	// $size == 'full' has no constraint

	else {

		$max_width = $width;

		$max_height = $height;

	}

	list( $max_width, $max_height ) = apply_filters( 'editor_max_image_size', array( $max_width, $max_height ), $size, $context );

	return wp_constrain_dimensions( $width, $height, $max_width, $max_height );

}

/**

 * Retrieve width and height attributes using given width and height values.

 *

 * Both attributes are required in the sense that both parameters must have a

 * value, but are optional in that if you set them to false or null, then they

 * will not be added to the returned string.

 *

 * You can set the value using a string, but it will only take numeric values.

 * If you wish to put 'px' after the numbers, then it will be stripped out of

 * the return.

 *

 * @since 2.5.0

 *

 * @param int|string $width Optional. Width attribute value.

 * @param int|string $height Optional. Height attribute value.

 * @return string HTML attributes for width and, or height.

 */

function image_hwstring($width, $height) {

	$out = '';

	if ($width)

		$out .= 'width="'.intval($width).'" ';

	if ($height)

		$out .= 'height="'.intval($height).'" ';

	return $out;

}

/**

 * Scale an image to fit a particular size (such as 'thumb' or 'medium').

 *

 * Array with image url, width, height, and whether is intermediate size, in

 * that order is returned on success is returned. $is_intermediate is true if

 * $url is a resized image, false if it is the original.

 *

 * The URL might be the original image, or it might be a resized version. This

 * function won't create a new resized copy, it will just return an already

 * resized one if it exists.

 *

 * A plugin may use the 'image_downsize' filter to hook into and offer image

 * resizing services for images. The hook must return an array with the same

 * elements that are returned in the function. The first element being the URL

 * to the new image that was resized.

 *

 * @since 2.5.0

 * @uses apply_filters() Calls 'image_downsize' on $id and $size to provide

 *		resize services.

 *

 * @param int $id Attachment ID for image.

 * @param array|string $size Optional, default is 'medium'. Size of image, either array or string.

 * @return bool|array False on failure, array on success.

 */

function image_downsize($id, $size = 'medium') {

	if ( !wp_attachment_is_image($id) )

		return false;

	// plugins can use this to provide resize services

	if ( $out = apply_filters( 'image_downsize', false, $id, $size ) )

		return $out;

	$img_url = wp_get_attachment_url($id);

	$meta = wp_get_attachment_metadata($id);

	$width = $height = 0;

	$is_intermediate = false;

	$img_url_basename = wp_basename($img_url);

	// try for a new style intermediate size

	if ( $intermediate = image_get_intermediate_size($id, $size) ) {

		$img_url = str_replace($img_url_basename, $intermediate['file'], $img_url);

		$width = $intermediate['width'];

		$height = $intermediate['height'];

		$is_intermediate = true;

	}

	elseif ( $size == 'thumbnail' ) {

		// fall back to the old thumbnail

		if ( ($thumb_file = wp_get_attachment_thumb_file($id)) && $info = getimagesize($thumb_file) ) {

			$img_url = str_replace($img_url_basename, wp_basename($thumb_file), $img_url);

			$width = $info[0];

			$height = $info[1];

			$is_intermediate = true;

		}

	}

	if ( !$width && !$height && isset( $meta['width'], $meta['height'] ) ) {

		// any other type: use the real image

		$width = $meta['width'];

		$height = $meta['height'];

	}

	if ( $img_url) {

		// we have the actual image size, but might need to further constrain it if content_width is narrower

		list( $width, $height ) = image_constrain_size_for_editor( $width, $height, $size );

		return array( $img_url, $width, $height, $is_intermediate );

	}

	return false;

}

/**

 * Registers a new image size

 *

 * @since 2.9.0

 */

function add_image_size( $name, $width = 0, $height = 0, $crop = false ) {

	global $_wp_additional_image_sizes;

	$_wp_additional_image_sizes[$name] = array( 'width' => absint( $width ), 'height' => absint( $height ), 'crop' => (bool) $crop );

}

/**

 * Registers an image size for the post thumbnail

 *

 * @since 2.9.0

 */

function set_post_thumbnail_size( $width = 0, $height = 0, $crop = false ) {

	add_image_size( 'post-thumbnail', $width, $height, $crop );

}

/**

 * An <img src /> tag for an image attachment, scaling it down if requested.

 *

 * The filter 'get_image_tag_class' allows for changing the class name for the

 * image without having to use regular expressions on the HTML content. The

 * parameters are: what WordPress will use for the class, the Attachment ID,

 * image align value, and the size the image should be.

 *

 * The second filter 'get_image_tag' has the HTML content, which can then be

 * further manipulated by a plugin to change all attribute values and even HTML

 * content.

 *

 * @since 2.5.0

 *

 * @uses apply_filters() The 'get_image_tag_class' filter is the IMG element

 *		class attribute.

 * @uses apply_filters() The 'get_image_tag' filter is the full IMG element with

 *		all attributes.

 *

 * @param int $id Attachment ID.

 * @param string $alt Image Description for the alt attribute.

 * @param string $title Image Description for the title attribute.

 * @param string $align Part of the class name for aligning the image.

 * @param string $size Optional. Default is 'medium'.

 * @return string HTML IMG element for given image attachment

 */

function get_image_tag($id, $alt, $title, $align, $size='medium') {

	list( $img_src, $width, $height ) = image_downsize($id, $size);

	$hwstring = image_hwstring($width, $height);

	$title = $title ? 'title="' . esc_attr( $title ) . '" ' : '';

	$class = 'align' . esc_attr($align) .' size-' . esc_attr($size) . ' wp-image-' . $id;

	$class = apply_filters('get_image_tag_class', $class, $id, $align, $size);

	$html = '<img src="' . esc_attr($img_src) . '" alt="' . esc_attr($alt) . '" ' . $title . $hwstring . 'class="' . $class . '" />';

	$html = apply_filters( 'get_image_tag', $html, $id, $alt, $title, $align, $size );

	return $html;

}

/**

 * Calculates the new dimensions for a downsampled image.

 *

 * If either width or height are empty, no constraint is applied on

 * that dimension.

 *

 * @since 2.5.0

 *

 * @param int $current_width Current width of the image.

 * @param int $current_height Current height of the image.

 * @param int $max_width Optional. Maximum wanted width.

 * @param int $max_height Optional. Maximum wanted height.

 * @return array First item is the width, the second item is the height.

 */

function wp_constrain_dimensions( $current_width, $current_height, $max_width=0, $max_height=0 ) {

	if ( !$max_width and !$max_height )

		return array( $current_width, $current_height );

	$width_ratio = $height_ratio = 1.0;

	$did_width = $did_height = false;

	if ( $max_width > 0 && $current_width > 0 && $current_width > $max_width ) {

		$width_ratio = $max_width / $current_width;

		$did_width = true;

	}

	if ( $max_height > 0 && $current_height > 0 && $current_height > $max_height ) {

		$height_ratio = $max_height / $current_height;

		$did_height = true;

	}

	// Calculate the larger/smaller ratios

	$smaller_ratio = min( $width_ratio, $height_ratio );

	$larger_ratio  = max( $width_ratio, $height_ratio );

	if ( intval( $current_width * $larger_ratio ) > $max_width || intval( $current_height * $larger_ratio ) > $max_height )

 		// The larger ratio is too big. It would result in an overflow.

		$ratio = $smaller_ratio;

	else

		// The larger ratio fits, and is likely to be a more "snug" fit.

		$ratio = $larger_ratio;

	// Very small dimensions may result in 0, 1 should be the minimum.

	$w = max ( 1, intval( $current_width  * $ratio ) );

	$h = max ( 1, intval( $current_height * $ratio ) );

	// Sometimes, due to rounding, we'll end up with a result like this: 465x700 in a 177x177 box is 117x176... a pixel short

	// We also have issues with recursive calls resulting in an ever-changing result. Constraining to the result of a constraint should yield the original result.

	// Thus we look for dimensions that are one pixel shy of the max value and bump them up

	if ( $did_width && $w == $max_width - 1 )

		$w = $max_width; // Round it up

	if ( $did_height && $h == $max_height - 1 )

		$h = $max_height; // Round it up

	return array( $w, $h );

}

/**

 * Retrieve calculated resized dimensions for use in WP_Image_Editor.

 *

 * Calculate dimensions and coordinates for a resized image that fits within a

 * specified width and height. If $crop is true, the largest matching central

 * portion of the image will be cropped out and resized to the required size.

 *

 * @since 2.5.0

 * @uses apply_filters() Calls 'image_resize_dimensions' on $orig_w, $orig_h, $dest_w, $dest_h and

 *		$crop to provide custom resize dimensions.

 *

 * @param int $orig_w Original width.

 * @param int $orig_h Original height.

 * @param int $dest_w New width.

 * @param int $dest_h New height.

 * @param bool $crop Optional, default is false. Whether to crop image or resize.

 * @return bool|array False on failure. Returned array matches parameters for imagecopyresampled() PHP function.

 */

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;

	// plugins can use this to provide custom resize dimensions

	$output = apply_filters( 'image_resize_dimensions', null, $orig_w, $orig_h, $dest_w, $dest_h, $crop );

	if ( null !== $output )

		return $output;

	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 );

}

/**

 * Resize an image to make a thumbnail or intermediate size.

 *

 * The returned array has the file size, the image width, and image height. The

 * filter 'image_make_intermediate_size' can be used to hook in and change the

 * values of the returned array. The only parameter is the resized file path.

 *

 * @since 2.5.0

 *

 * @param string $file File path.

 * @param int $width Image width.

 * @param int $height Image height.

 * @param bool $crop Optional, default is false. Whether to crop image to specified height and width or resize.

 * @return bool|array False, if no image was created. Metadata array on success.

 */

function image_make_intermediate_size( $file, $width, $height, $crop = false ) {

	if ( $width || $height ) {

		$editor = wp_get_image_editor( $file );

		if ( is_wp_error( $editor ) || is_wp_error( $editor->resize( $width, $height, $crop ) ) )

			return false;

		$resized_file = $editor->save();

		if ( ! is_wp_error( $resized_file ) && $resized_file ) {

			unset( $resized_file['path'] );

			return $resized_file;

		}

	}

	return false;

}

/**

 * Retrieve the image's intermediate size (resized) path, width, and height.

 *

 * The $size parameter can be an array with the width and height respectively.

 * If the size matches the 'sizes' metadata array for width and height, then it

 * will be used. If there is no direct match, then the nearest image size larger

 * than the specified size will be used. If nothing is found, then the function

 * will break out and return false.

 *

 * The metadata 'sizes' is used for compatible sizes that can be used for the

 * parameter $size value.

 *

 * The url path will be given, when the $size parameter is a string.

 *

 * If you are passing an array for the $size, you should consider using

 * add_image_size() so that a cropped version is generated. It's much more

 * efficient than having to find the closest-sized image and then having the

 * browser scale down the image.

 *

 * @since 2.5.0