[NTG-context] help with facing page image

[jbf]

Thanks Wolfgang. This version is the 'icing on the cake' I think, a 
further refined version of the suggestion put forward by Sreeram.

Grateful as always,

Julian

On 11/3/22 23:36, Wolfgang Schuster wrote:
> \definepageinjectionalternative
>   [chapter:image]
>   [renderingsetup=pageinjection:chapter:image]
>
> \startsetups [pageinjection:chapter:image]
>   \centerbox{\externalfigure[\dummyparameter{name}]}
> \stopsetups
>
> \definepageinjection
>   [chapter:start]
>   [empty]
>   [page=left]
>
> \definepageinjection
>   [chapter:insert]
>   [previouspage]
>   [alternative=chapter:image,
>    offset=1cm,
>    pagestate=stop]
>
> \setuphead
>   [chapter]
>   [beforesection={\pageinjection[chapter:start]},
> insidesection={\pageinjection[chapter:insert][name={chapter-\namedheadnumber{chapter}}]}] 
>
>
> \setuppagenumbering
>   [alternative=doublesided]
>
> \setupexternalfigures
>   [location=default]
>
> \useexternalfigure [chapter-1] [mill]   [factor=max]
> \useexternalfigure [chapter-2] [hacker] [orientation=90,scale=2000]
> \useexternalfigure [chapter-3] [cow] [orientation=90,height=\framedwidth]
>
> \starttext
>
> \startchapter [title={Mill}]
> \dorecurse{7}{\samplefile{lorem}}
> \stopchapter
>
> \startchapter [title={Hacker}]
> \dorecurse{11}{\samplefile{lorem}}
> \stopchapter
>
> \startchapter [title={cow}]
> \dorecurse{7}{\samplefile{lorem}}
> \stopchapter
>
> \stoptext