hugo-theme-hilfe/layouts/shortcodes/img.html

{{ $source := ($.Page.Resources.ByType "image").GetMatch (printf "%s" (.Get "name")) }}
{{ $customAlt := .Get "alt" }}
{{ $customSize := .Get "size" }}
{{ $lazyLoad := default (default true $.Site.Params.GeekdocImageLazyLoading) (.Get "lazy") }}

{{ with $source }}
{{ $caption := default .Title $customAlt }}

{{ $tiny := (.Resize "320x").RelPermalink }}
{{ $small := (.Resize "600x").RelPermalink }}
{{ $medium := (.Resize "1200x").RelPermalink }}
{{ $large := (.Resize "1800x").RelPermalink }}

{{ $size := dict "tiny" $tiny "small" $small "medium" $medium "large" $large }}

<div class="flex justify-center">
<figure class="gdoc-markdown__figure">
    <a class="gdoc-markdown__link--raw" href="{{ .RelPermalink }}">
        <picture>
            <source
                {{ with $customSize }}
                srcset="{{ index $size $customSize }}"
                {{ else }}
                srcset="{{ $size.small }} 600w,
                        {{ $size.medium }} 1200w"
                sizes="100vw"
                {{ end }} />
            <img
                {{ if $lazyLoad }}loading="lazy"{{ end }}
                src="{{ $size.large }}" alt="{{ $caption }}" />
        </picture>
    </a>
    {{ with $caption }}
    <figcaption>{{ . }}{{ with $source.Params.credits }} ({{ . | $.Page.RenderString }}){{ end }}</figcaption>
    {{ end }}
</figure>
</div>
{{ end }}