%D \module
%D   [       file=math-inl,
%D        version=2008.10.20,
%D          title=\CONTEXT\ Math Macros,
%D       subtitle=Inline,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright=PRAGMA-ADE / Hans Hagen]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

\writestatus{loading}{ConTeXt Math Macros / Inline}

\unprotect

%D \macros
%D   {...}
%D
%D New and experimental: snapping big inline math!

\newconditional\halfcrazymathlines % \settrue\halfcrazymathlines
\newconditional\crazymathsnapping  % \settrue\crazymathsnapping

\appendtoks
 \doifelse\@@mtgrid\v!yes     \settrue\setfalse\crazymathsnapping
 \doifelse\@@mtstep\v!halfline\settrue\setfalse\halfcrazymathlines
\to \everysetuptextformulas

\setuptextformulas
  [\c!grid=\v!yes,
   \c!step=\v!line]

\newcount\crazymathhack

\let\lastcrazymathline     \!!zeropoint
\let\lastcrazymathpage     \!!zerocount
\let\lastcrazymathprelines \!!zerocount
\let\lastcrazymathpostlines\!!zerocount

\def\crazymathtag{amh:\the\crazymathhack}
\def\crazytexttag{\v!text:\lastcrazymathpage}

\def\crazymathindent{\hskip\MPx\crazymathtag\hskip-\MPx\crazytexttag}

\def\flushcrazymathbox
  {\nextboxht\strutheight
   \nextboxdp\strutdepth
   \hbox{\iftracegridsnapping\ruledhbox\fi{\flushnextbox}}}

\def\snappedinlineformula
  {\dosingleempty\dosnappedinlineformula}

%D \starttabulate[|Tl|l|]
%D \NC - \NC half lines        \NC \NR
%D \NC + \NC full lines        \NC \NR
%D \NC = \NC force             \NC \NR
%D \NC < \NC force, minus pre  \NC \NR
%D \NC > \NC force, minus post \NC \NR
%D \stoptabulate

\def\inlinemathmargin{1pt}

\settrue\autocrazymathsnapping

% FROM NOW ON, CHANGES AS OPTIONS

% TODO: SKYLINE (PREV LINE POS SCAN)

% we can rewrite this in lua but maybe we don't need it
% any more when we have proper snapping anyway

\def\dosnappedinlineformula[#1]#2%
  {\ifvmode\dontleavehmode\fi % tricky
   \strut % prevents funny space at line break
   \begingroup % interesting: \bgroup can make \vadjust disappear
   \ifconditional\crazymathsnapping
     \ifgridsnapping
       \checktextbackgrounds % we need pos tracking, to be made less redundant
       \donetrue
     \else
       \donefalse
     \fi
   \else
     \donefalse
   \fi
   \!!doneafalse % forced or not auto
   \!!donebfalse % too heigh
   \!!donecfalse % too low
   \!!donedfalse % less before
   \!!doneefalse % less after
   \ifdone
     \setbox\nextbox\hbox{$#2$}%
     \iftracegridsnapping
       \setbox\nextbox\ruledhbox
         {\backgroundline[gray]{\showstruts\strut\flushnextbox}}%
     \fi
     \def\docommand##1%
       {\doif{##1}-{\settrue \halfcrazymathlines}%
        \doif{##1}+{\setfalse\halfcrazymathlines}%
        \doif{##1}={\!!doneatrue}%
        \doif{##1}<{\!!donedtrue}%
        \doif{##1}>{\!!doneetrue}}%
     \processcommalist[#1]\docommand
     \if!!doneb
       \if!!donec \else
         \setfalse\halfcrazymathlines
       \fi
     \else
       \if!!donec
         \setfalse\halfcrazymathlines
       \fi
     \fi
     \donefalse
     \if!!donea
       \donetrue
     \scratchdimen \nextboxht
     \advance\scratchdimen .5\lineheight
     \nextboxht\scratchdimen
     \scratchdimen \nextboxdp
     \advance\scratchdimen .5\lineheight
     \nextboxdp\scratchdimen
     \else\ifdim\nextboxht>\strutht
       \donetrue
     \else\ifdim\nextboxdp>\strutdp
       \donetrue
     \fi\fi\fi
     \ifconditional\autocrazymathsnapping \else \if!!donea \else
       % don't compensate, just snap to strut
       \donefalse
       % signal for next else, snap line to strut
       \!!doneatrue
     \fi \fi
   \fi
   \ifdone
     % analyze height
     \scratchdimen\inlinemathmargin
     \advance\scratchdimen \strutht
     \ifdim\nextboxht<\scratchdimen \else \!!donebtrue \fi
     % analyze depth
     \scratchdimen\inlinemathmargin
     \advance\scratchdimen \strutdp
     \ifdim\nextboxdp<\scratchdimen \else \!!donectrue \fi
     % analyzed or forced
     \ifdone
       \global\advance\crazymathhack\plusone
       \donefalse
       \ifnum\MPp\crazymathtag=\lastcrazymathpage\relax
         \ifdim\MPy\crazymathtag=\lastcrazymathline\relax
           \donetrue
         \fi
       \fi
       \ifnum\MPp\crazymathtag=\zerocount \donefalse \fi
       \ifdim\MPy\crazymathtag=\zeropoint \donefalse \fi
       \ifdone
         % same page and same line
       \else
         \global\let\lastcrazymathprelines \!!zerocount
         \global\let\lastcrazymathpostlines\!!zerocount
         \xdef\lastcrazymathpage{\MPp\crazymathtag}%
         \xdef\lastcrazymathline{\MPy\crazymathtag}%
       \fi
       \if!!doneb
       % \getrawnoflines\nextboxht
         \scratchdimen\nextboxht
         \advance\scratchdimen-\strutht
         \getnoflines\scratchdimen
         \if!!doned \advance\noflines\minusone \fi
         \scratchcounter\noflines
         \advance\noflines-\lastcrazymathprelines\relax
         \ifnum\noflines>\zerocount
           \xdef\lastcrazymathprelines{\the\scratchcounter}%
           \scratchdimen\noflines\lineheight
           \ifconditional\halfcrazymathlines
             \advance\scratchdimen-.5\lineheight
           \fi
           \advance\scratchdimen-\strutdepth
           \setbox\scratchbox\null
           \wd\scratchbox2\bodyfontsize
           \ht\scratchbox\scratchdimen
           \dp\scratchbox\strutdepth
           %%% top correction code (see below)
           \normalvadjust pre
             {%\allowbreak % sometimes breaks spacing
              \forgetall
              \crazymathindent
              \iftracegridsnapping
                \setbox\scratchbox\hbox{\green\ruledhbox{\box\scratchbox}}%
              \fi
              \box\scratchbox
              \endgraf
              \nobreak}%
         \else\ifnum\scratchcounter>\zerocount
           \normalvadjust pre
             {\nobreak}%
         \fi\fi
       \fi
       \if!!donec
       % \getrawnoflines\nextboxdp
         \scratchdimen\nextboxdp
         \advance\scratchdimen-\strutdp
         \getnoflines\scratchdimen
         \if!!donee \advance\noflines\minusone \fi
         \scratchcounter\noflines
         \advance\noflines-\lastcrazymathpostlines\relax
         \ifnum\noflines>\zerocount
           \donetrue
         \else\ifnum\lastcrazymathpostlines=\zerocount
           \donetrue
         \else
           \donefalse
         \fi\fi
       \else
         \donefalse
       \fi
       \ifdone
         \xdef\lastcrazymathpostlines{\the\scratchcounter}%
         \ifnum\lastcrazymathpostlines=\zerocount
           \global\let\lastcrazymathpostlines\!!plusone
         \fi
         \hbox{\setposition\crazymathtag\flushcrazymathbox}%
         \scratchdimen\noflines\lineheight
         \advance\scratchdimen-\lineheight
         \advance\scratchdimen+\strutheight
         \ifdim\scratchdimen>\zeropoint \else
           \scratchdimen\strutheight % todo : test for half lines
         \fi
         \ifconditional\halfcrazymathlines
           \advance\scratchdimen-.5\lineheight
         \fi
         \setbox\scratchbox\null
         \wd\scratchbox2\bodyfontsize
         \ht\scratchbox\scratchdimen
         \dp\scratchbox\strutdepth
         \normalvadjust
           {\forgetall
            \crazymathindent
            \iftracegridsnapping
              \setbox\scratchbox\hbox{\blue\ruledhbox{\box\scratchbox}}%
            \fi
            \box\scratchbox
            \endgraf
            % precaution: else we stick below the text bottom
            \ifconditional\halfcrazymathlines
              \allowbreak
            \else
              \vskip-\lineheight
              \vskip \lineheight
           \fi}%
       \else
         \hbox{\setposition\crazymathtag\flushcrazymathbox}%
       \fi
     \else
       \flushcrazymathbox
     \fi
   \else\if!!donea
     \flushcrazymathbox
   \else
     \mathematics{#2}%
   \fi\fi
   \endgroup}

\let\tform\mathematics
\let\gform\snappedinlineformula

% test set:
%
% \startbuffer
% Crazy math \gform {1+x} or \gform {\dorecurse {100} {1+} 1 =
% 101} and even gore crazy \gform {2^{2^2}_{1_1}}
% again\dorecurse {20} { and again} \gform {\sqrt {\frac
% {x^{5^5}} {\frac {1} {2}}}} even gore\dorecurse {50} { and
% gore} \tform {\dorecurse {12} {\gform {\sqrt {\frac
% {x^{5^5}} {3}}}+\gform {\sqrt {\frac {x^{5^5}} {\frac {1}
% {2}}}}+}x=10}\dorecurse{20} { super crazy math}: \tform
% {\dorecurse {30} {\gform {\sqrt {\frac {x^{5^5}} {3}}}+
% \gform {\sqrt {\frac {x^{5^5}} {\frac {1} {2}}}}+ }x = 10},
% and we're\dorecurse {20} { done}!
% \stopbuffer
%
% \setupcolors[state=start] \setuppapersize[S6][S6]
%
% \showgrid \tracegridsnappingtrue \showstruts
%
% \starttext
% \setuplayout[grid=yes,lines=15]\getbuffer \page
% \setuplayout[grid=yes,lines=16]\getbuffer \page
% \setuplayout[grid=yes,lines=17]\getbuffer \page
% \setuplayout[grid=yes,lines=18]\getbuffer \page
% \setuplayout[grid=yes,lines=19]\getbuffer \page
% \stoptext
%
% test
%
% \startregels
% \gform[<]{35 \cdot p^{\frac{3}{4}} = 70}
% \gform{12{,}4 \cdot d^3 = 200}
% \gform{a \cdot x^b}.
% \gform{12x^6 \cdot \negative 3x^4}
% \gform{\frac{12x^6}{\negative 3x^4}}
% \gform{(4x^2)^3}
% \gform{4x \sqrt{x} \cdot 3x^2}
% \gform{\frac{2x^4}{4x \sqrt{x}}}
% \gform{y = a \cdot x^b}.
% \gform{y_1 = \frac{15x^2}{x}}
% \gform{y_2 = x \cdot \sqrt{x}}
% \gform{y_3 = \frac{6x^3}{x^2}}
% \gform[<]{y_4 = \left(2x^2\right)^{\frac{1}{2}}}
% \gform{y_1 = \frac{4x^5}{x^2}}
% \gform{y_2 = 4 \cdot \sqrt{x}}
% \gform{y_3 = 4x^3}
% \gform{y_4 = \frac{100x}{\sqrt{x}}}
% \gform[<]{y_5 = 4 \cdot x^{\frac{1}{2}}}
% \gform{y_6 = \frac{1}{2} x \cdot 4x^2}
% \gform{y_7 = 2 \cdot x^3}
% \gform{y_8 = 100 \cdot x^{\frac{1}{2}}}
% \gform{4x^8 \cdot 8x^3}
% \gform{\frac{4x^8}{8x^3}}
% \gform{\left(\negative3x^4\right)^3}
% \gform{x^3 \sqrt{x} \cdot 3x^2}
% \gform{\frac{6x^3}{x^2 \sqrt{x}}}
% \gform{\frac{6}{2x^4}}
% \gform{\frac{1}{3x^6}}
% \gform{\frac{12x^8}{4x^{10}}}
% \gform{\frac{4}{\sqrt{x}}}
% \gform{\frac{1}{2x \sqrt{x}}}
% \gform{\frac{2{,}25}{p} = 0{,}35}
% \gform{4{,}50 + \frac{300}{k} = 4{,}70}
% \gform{\frac{1200}{k+12} - 42 = 6}
% \stopregels

%D \macros
%D   {enableautomath}
%D
%D The next one can be dangerous, but handy in controlled
%D situations.

\bgroup \catcode`\$=\active

\gdef\enableautomath
  {\catcode`\$=\active
   \def$##1${\snappedinlineformula{##1}}}

% \gdef\enableautomath
%   {\catcode`\$=\active
%    \def${\doifnextcharelse$\doautodmath\doautoimath}%
%    \def\doautoimath##1${\snappedinlineformula{##1}}%
%    \def\doautodmath$##1$${\startformula##1\stopformula}}

\egroup

\protect \endinput