wp_constrain_dimensions( int $current_width, int $current_height, int $max_width, int $max_height )
Calculates the new dimensions for a down-sampled image.
Description
If either width or height are empty, no constraint is applied on that dimension.
Parameters
- $current_width
-
(Required) Current width of the image.
- $current_height
-
(Required) Current height of the image.
- $max_width
-
(Optional) Max width in pixels to constrain to. Default 0.
- $max_height
-
(Optional) Max height in pixels to constrain to. Default 0.
Return
(array) First item is the width, the second item is the height.
Source
File: wp-includes/media.php
function wp_constrain_dimensions( $current_width, $current_height, $max_width = 0, $max_height = 0 ) {
if ( !$max_width && !$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 ( (int) round( $current_width * $larger_ratio ) > $max_width || (int) round( $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, (int) round( $current_width * $ratio ) );
$h = max ( 1, (int) round( $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
// Note: $did_width means it is possible $smaller_ratio == $width_ratio.
if ( $did_width && $w == $max_width - 1 ) {
$w = $max_width; // Round it up
}
// Note: $did_height means it is possible $smaller_ratio == $height_ratio.
if ( $did_height && $h == $max_height - 1 ) {
$h = $max_height; // Round it up
}
/**
* Filters dimensions to constrain down-sampled images to.
*
* @since WP-4.1.0
*
* @param array $dimensions The image width and height.
* @param int $current_width The current width of the image.
* @param int $current_height The current height of the image.
* @param int $max_width The maximum width permitted.
* @param int $max_height The maximum height permitted.
*/
return apply_filters( 'wp_constrain_dimensions', array( $w, $h ), $current_width, $current_height, $max_width, $max_height );
}
Changelog
Version | Description |
---|---|
WP-2.5.0 | Introduced. |