thanks to the code ninjas @ kriesi.at = excellent support guys!
THANKS!

But it does not seem to work on post thumbs – i don’t know why …?

For all searching people: use this script in functions.php – with your extension:

// Enqueueing retina.js
if(!is_admin())
{
	add_action('wp_enqueue_scripts', 'avia_register_child_frontend_scripts', 100);
}

function avia_register_child_frontend_scripts()
{
	$child_theme_url = get_stylesheet_directory_uri();
        wp_enqueue_script( 'retina_js', $child_theme_url.'/js/retina.js', '', '', true );
}

add_filter( 'wp_generate_attachment_metadata', 'retina_support_attachment_meta', 10, 2 );
/**
 * Retina images
 *
 * This function is attached to the 'wp_generate_attachment_metadata' filter hook.
 */
function retina_support_attachment_meta( $metadata, $attachment_id ) {
    foreach ( $metadata as $key => $value ) {
        if ( is_array( $value ) ) {
            foreach ( $value as $image => $attr ) {
                if ( is_array( $attr ) )
                    retina_support_create_images( get_attached_file( $attachment_id ), $attr['width'], $attr['height'], true );
            }
        }
    }

    return $metadata;
}

/**
 * Create retina-ready images
 *
 * Referenced via retina_support_attachment_meta().
 */
function retina_support_create_images( $file, $width, $height, $crop = false ) {
    if ( $width || $height ) {
        $resized_file = wp_get_image_editor( $file );
        if ( ! is_wp_error( $resized_file ) ) {
            $filename = $resized_file->generate_filename( $width . 'x' . $height . '@2x' );

            $resized_file->resize( $width * 2, $height * 2, $crop );
            $resized_file->save( $filename );

            $info = $resized_file->get_size();

            return array(
                'file' => wp_basename( $filename ),
                'width' => $info['width'],
                'height' => $info['height'],
            );
        }
    }
    return false;
}

add_filter( 'delete_attachment', 'delete_retina_support_images' );
/**
 * Retina Bilder loeschen
 *
 */
function delete_retina_support_images( $attachment_id ) {
    $meta = wp_get_attachment_metadata( $attachment_id );
    $upload_dir = wp_upload_dir();
    $path = pathinfo( $meta['file'] );
    foreach ( $meta as $key => $value ) {
        if ( 'sizes' === $key ) {
            foreach ( $value as $sizes => $size ) {
                $original_filename = $upload_dir['basedir'] . '/' . $path['dirname'] . '/' . $size['file'];
                $retina_filename = substr_replace( $original_filename, '@2x.', strrpos( $original_filename, '.' ), strlen( '.' ) );
                if ( file_exists( $retina_filename ) )
                    unlink( $retina_filename );
            }
        }
    }
}
// FUNCTIONS END RETINA SCRIPT

• This reply was modified 10 years, 7 months ago by basmati.

ok, got it with a lot of css styles and page ids. topic closed

yep ismael, that works – but after surfing some pages the logo link points to the same page your on.
my knowledge of php is not so strong – but it seems like it needs a piece of code for outputing the home link on every page / post.
do you know what i mean?

also – the search form is missing in the main menu for logged in users

• This reply was modified 10 years, 7 months ago by basmati.

ok – i found it
but there seems to be no media query for the logo –
the height is reduced to 80px (!important) – why is that?

how to change the height?
the file is 600px x 70px @2x = 300px x 35px (2:1)

.responsive .logo a, .responsive .logo img {
    height: 80px !important;
    margin: 0 auto;
    max-height: 80px !important;
    max-width: 100%;
}

• This reply was modified 10 years, 7 months ago by basmati.

it worked out with that function:
http://code.tutsplus.com/tutorials/ensuring-your-theme-has-retina-support–wp-33430

• This reply was modified 10 years, 7 months ago by basmati.