% language=us

% Please try to be original and don't just copy this cover page as I don't want
% confusion and be associated with (or responsibility for the look of) similar
% looking documents.

\startenvironment manuals-explaining-cover

\startsetups document:abstract
    \framed [
        foregroundstyle=bold,
        foregroundcolor=white,
        width=7.5cm,
        align={normal,tolerant},
        frame=off,
        strut=no,
    ] {
        \getbuffer[abstract]
    }
\stopsetups

\startMPinclusions

    def DrawCoverPage (expr what) =

        numeric variant ; variant := 1 ;

        StartCover ;

            save width, height, size, anchor, offset, colors ;

            numeric width, height, size ; pair anchor, offset ; string colors[] ;

            colors[1] := "\documentvariable{cover:color:1}" ;
            colors[2] := "\documentvariable{cover:color:2}" ;
            colors[3] := "\documentvariable{cover:color:3}" ;
            colors[4] := "\documentvariable{cover:color:4}" ;
            colors[5] := "\documentvariable{cover:color:5}" ;

            fill CoverPage enlarged PaperBleed withcolor colors[5] ;

            fill Spine bottomenlarged  -.5PaperHeight withcolor colors[3] ;
            fill Spine topenlarged     -.5PaperHeight withcolor colors[2] ;

            width  := FrontPageWidth ;
            height := FrontPageHeight ;
            size   := 4 * width / 3 ;
            offset := (-1cm,1cm) ;
            anchor := .5[lrcorner CoverPage,urcorner CoverPage] ;

            fill anchored.llft(lltriangle scaled size, urcorner FrontPage) withcolor colors[1] ;
            fill anchored.urt (urtriangle scaled size, llcorner FrontPage) withcolor colors[2] ;
            fill anchored.lrt (lrtriangle scaled size, ulcorner FrontPage) withcolor colors[3] ;
            fill anchored.ulft(ultriangle scaled size, lrcorner FrontPage) withcolor colors[4] ;

            fill anchored.lrt (lrtriangle scaled size, ulcorner BackPage) withcolor colors[1] ;
            fill anchored.llft(lltriangle scaled size, urcorner BackPage) withcolor colors[3] ;
            fill anchored.ulft(ultriangle scaled size, lrcorner BackPage) withcolor colors[2] ;
            fill anchored.urt (urtriangle scaled size, llcorner BackPage) withcolor colors[4] ;

            draw thetextext.llft(
                textext("\bf \documentvariable{title}\hskip-.1em")
                rotated 45 ysized .350height,
                anchor shifted (6*offset+offset)
            ) withcolor white ;
            draw thetextext.llft(
                textext("\bf \documentvariable{subtitle}")
                rotated 45 ysized .275height,
                anchor shifted (5*offset+offset)
            ) withcolor white ;
            draw thetextext.llft(
                textext("\bf \documentvariable{author}")
                rotated 45 ysized .200height,
                anchor shifted (2*offset+offset)
            ) withcolor white ;
            draw thetextext.llft(
                textext("\bf \documentvariable{affiliation}")
                rotated 45 ysized .200height,
                anchor shifted (1*offset+offset)
            ) withcolor white ;

            % for the moment

            if (what = "back") or (what = "cover") :

                draw
                    thetextext.top(
                        textext("\bf \documentvariable{comment}")
                        xsized 4cm,
                        lrcorner Page shifted (-3cm,1cm)
                    ) withcolor white ;

            fi ;

            % till here

            width := BackPageWidth ;

            if (what = "back") or (what = "cover") :

                draw thetextext(
                    textext("\bf\setups[document:abstract]")
                    xsized .65width rotated 45,
                    center BackPage
                ) withcolor white ;

            fi ;

            if what = "cover" :

                draw thetextext.bot(
                    textext("\bf \documentvariable{title}\hskip-.1em")
                    rotated 90 xsized .8SpineWidth,
                    .5[ulcorner Spine,urcorner Spine] shifted (0,-1cm)
                ) withcolor white ;

                draw thetextext.top(
                    textext("\bf \documentvariable{author}")
                    rotated 90 xsized .8SpineWidth,
                    .5[llcorner Spine,lrcorner Spine] shifted (0,1cm)
                ) withcolor white ;

            fi ;

        StopCover ;

        if what = "front" :
            clip currentpicture to FrontPage ;
        elseif what = "back" :
            clip currentpicture to BackPage ;
        else :
            drawboundary CoverPage ;
        fi ;

    enddef ;

\stopMPinclusions

\startsetups document:start

    % \startcovermatter[front]

    \setupbackgrounds[page][background=]

    \doifmodeelse {simple} {

        \startMPpage
            DrawCoverPage("front") ;
        \stopMPpage

    } {

        \startMPpage
            DrawCoverPage("cover") ;
        \stopMPpage

    }

    \page[dummy]

    \setupbackgrounds[page][background=page]

    \resetuserpagenumber

    % \stopcovermatter

\stopsetups

\startsetups document:stop

    \doifmodeelse {simple} {

        % \startcovermatter[back]

        \page

        \setuppagenumbering[page=]

        \setupbackgrounds[page][background=]

        \page[empty,left]

        \setupmakeup[doublesided=no,page=no]

        \startMPpage
            DrawCoverPage("back") ;
        \stopMPpage

        % \stopcovermatter

    } {

       % not needed as it's part of the cover page

    }

\stopsetups

\stopenvironment