%%%%%%%%%% Hiding/printing bar lines individually %%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Here comes a bunch of rather general macros which enable printing or 
% hiding barlines for each staff and inter-staff space individually:
%
% Mthimkhulu Molekwa <MMolekwa@rrs.co.za>

\ifx\indivbarrules\undefined\else\endinput\fi

\immediate\write16{MusiXBAR printing or hiding seperate bar lines 1.01\space<23 Februar 2000>}%

\edef\catcodeat{\the\catcode`\@}\catcode`\@=11

%\makeatletter

\newdimen\barline@depth
  
\def\rul@indiv#1{%
  \n@loop
    \Comp@High
    \expandafter\ifx\csname s@b\romannumeral\noinstrum@nt\endcsname\relax
      \multiply\barline@depth -1\relax
      \advance\barline@depth\altitude
    \else
      \barline@depth=0pt\relax
    \fi
    {\expandafter\ifx\csname h@bl\romannumeral\noinstrum@nt\endcsname 1%
       \y@v=0pt\relax
     \fi
     \raise\altitude\rlap{\vrule\@depth\barline@depth\@width#1\@height\y@v}}%
    \barline@depth\altitude
    \advance\barline@depth\y@v
  \repeat
  \addspace#1}

\def\rul@indiv@#1{\n@loop{\prul@indiv@#1}\repeat\addspace#1}

\def\prul@indiv@#1{%
      \y@v\interportee \C@Inter\advance\y@v-\stem@skip
      \expandafter\ifx\csname s@b\romannumeral\noinstrum@nt\endcsname\relax
        \multiply\barline@depth -1\relax
        \advance\barline@depth\altitude
      \else
        \barline@depth=0pt\relax
      \fi
      {\expandafter\ifx\csname h@bl\romannumeral\noinstrum@nt\endcsname 1%
         \y@v=0pt\relax
       \fi
      \p@loop
        \raise\altportee\rlap{%
          \vrule\@depth\barline@depth\@width#1\@height\y@v}%
        \count@portee
      \repeat}%
      \barline@depth\altitude
      \advance\barline@depth\y@v}

%== Required to use the following macros
\def\indivbarrules{%
  \let\writ@rule\rul@indiv
  \sepbarrule 1}

\def\Indivbarrules{%
  \let\writ@rule\rul@indiv@
  \sepbarrule 1}

%== separates bar line of specified instrument from one of previous instrument
\def\sepbarrule#1{\expandafter\let\csname s@b\romannumeral#1\endcsname 1}

%== connects bar line of specified instrument to one of previous instrument
\def\conbarrule#1{%
  \if 1#1\else\expandafter\let\csname s@b\romannumeral#1\endcsname\relax\fi}
  
%== hides bar line for specified instrument
\def\hidebarrule#1{\expandafter\let\csname h@bl\romannumeral#1\endcsname 1}
  
%== shows bar line for specified instrument
\def\showbarrule#1{\expandafter\let\csname h@bl\romannumeral#1\endcsname\relax}

%== separates barlines in multistaff instruments
\def\rul@sep@#1{\n@loop{\prul@sep#1}\repeat\addspace#1}

\def\prul@sep#1{%
      \y@v\interportee \C@Inter\advance\y@v-\stem@skip
      \p@loop
        \hbox{\raise\altportee\rlap{%
          \vrule\@depth\hlthick\@width#1\@height\y@v}}%
        \count@portee\repeat}

\def\Sepbarrules{\let\writ@rule\rul@sep@ }

%-\makeatother

\catcode`\@=\catcodeat
\endinput

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% Here comes an example of how to use these macros

%%%%% Pre-amble
\input musixtex
\input musixbar

\instrumentnumber3
\setmeter3{{\meterfrac{3}{4}}}
\setmeter2{{\meterfrac{2}{4}}}
\setmeter1{{\meterfrac{3}{8}}}
\nobarnumbers
\indivbarrules
\sepbarrule2
\sepbarrule3

%%%%% Spacing
\beforeruleskip=0.5\afterruleskip
\interinstrument=4\Interligne

%%%%% Macros
\let\ni\nextinstrument

%%%%% Music
\linegoal2
\startpiece\addspace\afterruleskip
\NOtes\pt f\qa f\ni\qa f\ni\qa f\en
\hidebarrule2\hidebarrule3\bar
\NOtes\multnoteskip{.333}\Tqbu fff\ni\qa f\ni\qa f\en
\showbarrule2\bar
\NOtes\pt f\qa f\ni\qa f\ni\qa f\en
\hidebarrule2\showbarrule3\bar
\NOtes\multnoteskip{.333}\Tqbu fff\ni\qa f\ni\qa f\en
\showbarrule2\hidebarrule3\bar
\NOtes\pt f\qa f\ni\qa f\ni\qa f\en
\hidebarrule2\bar
\NOtes\multnoteskip{.333}\Tqbu fff\ni\qa f\ni\qa f\en
\showbarrule2\showbarrule3\bar
\NOtes\pt f\qa f\ni\qa f\ni\qa f\en
\hidebarrule2\hidebarrule3\bar
\NOtes\multnoteskip{.333}\Tqbu fff\ni\qa f\ni\qa f\en
\showbarrule2\bar
\NOtes\pt f\qa f\ni\qa f\ni\qa f\en
\hidebarrule2\showbarrule3\bar
\NOtes\multnoteskip{.333}\Tqbu fff\ni\qa f\ni\qa f\en
\showbarrule2\hidebarrule3\bar
\NOtes\pt f\qa f\ni\qa f\ni\qa f\en
\hidebarrule2\bar
\NOtes\multnoteskip{.333}\Tqbu fff\ni\qa f\ni\qa f\en
\showbarrule2\showbarrule3\stoppiece
\bye