2016-01-12 16:26:00

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diff --git a/tex/context/base/mkiv/grph-trf.mkiv b/tex/context/base/mkiv/grph-trf.mkiv
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+%D \module
+%D   [       file=grph-trf,
+%D        version=2006.08.26, % overhaul/split of 1997.03.31 core-fig
+%D          title=\CONTEXT\ Graphic Macros,
+%D       subtitle=Transformations,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
+%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 Graphic Macros / Transformations}
+
+\unprotect
+
+%D We probably use too many dimens as the width calculations can
+%D go away. Some of this is an inheritance of limited backends
+%D (some supported fractions, some 1000's, some dimentions) so
+%D we calculate all of them. Nowadays scaling is always available
+%D so we could simplify the code. On the other hand, we now get
+%D some extra values for free.
+%D
+%D We could move the calculations to \LUA\ and clean up this
+%D lot anyway. On the other hand, there is some danger of messing
+%D up so it has a real low priority.
+
+% local:
+
+\newdimen\d_grph_scale_x_size
+\newdimen\d_grph_scale_y_size
+\newdimen\d_grph_scale_x_offset
+\newdimen\d_grph_scale_y_offset
+
+\newdimen\d_grph_scale_h_size
+\newdimen\d_grph_scale_v_size
+
+\newconditional\c_grph_scale_done
+\newconditional\c_grph_scale_scaling_done
+\newconditional\c_grph_scale_limit_factors \settrue\c_grph_scale_limit_factors
+
+\newdimen\d_grph_scale_wd
+\newdimen\d_grph_scale_ht
+\newdimen\d_grph_scale_dp
+
+% global
+
+\newdimen\d_grph_scale_used_x_size
+\newdimen\d_grph_scale_used_y_size
+
+\newcount\c_grph_scale_used_x_scale
+\newcount\c_grph_scale_used_y_scale
+
+\let     \m_grph_scale_used_x_scale\!!plusone
+\let     \m_grph_scale_used_y_scale\!!plusone
+
+\newdimen\d_grph_scale_outer_v_size % we cannot manipulate any global vsize !
+
+% scratch:
+
+\let\m_grph_scale_temp  \empty
+\let\m_grph_scale_temp_x\empty
+\let\m_grph_scale_temp_y\empty
+
+% public:
+
+\let\finalscaleboxxscale \!!plusone
+\let\finalscaleboxyscale \!!plusone
+\let\finalscaleboxwidth  \!!zeropoint
+\let\finalscaleboxheight \!!zeropoint
+
+% we can let sx/sy win (first check)
+
+\installcorenamespace{scale}
+\installcorenamespace{scalegrid}
+\installcorenamespace{scalenorm}
+
+\installcommandhandler \??scale {scale} \??scale % we can have instances
+
+\setupscale
+  [\c!sx=\scaleparameter\c!s,
+   \c!sy=\scaleparameter\c!s,
+   \c!s=1,
+  %\c!scale=,
+  %\c!xscale=,
+  %\c!yscale=,
+  %\c!width=,
+  %\c!height=,
+  %\c!lines=,
+  %\c!factor=,
+  %\c!hfactor=,
+  %\c!wfactor=,
+  %\c!grid=,
+  %\c!equalwidth=,
+  %\c!equalheight=,
+   \c!maxwidth=\scaleparameter\c!width,
+   \c!maxheight=\scaleparameter\c!height]
+
+\unexpanded\def\scale{\dodoubleempty\grph_scale}
+
+% we could have: \freezeparameter\c!scale etc (less backtracking when used multiple)
+
+\def\grph_scale[#1][#2]%
+  {\bgroup
+   % this is quite common so we might make this a helper
+   \ifsecondargument
+     \edef\currentscale{#1}%
+     \setupcurrentscale[#2]%
+   \else\iffirstargument
+     \doifelseassignment{#1}
+       {\let\currentscale\empty
+        \setupcurrentscale[#1]}
+       {\edef\currentscale{#1}}%
+   \else
+     \let\currentscale\empty
+   \fi\fi
+   %
+   \dowithnextboxcs\grph_scale_finish\hbox}
+
+\def\grph_scale_finish
+  {% todo: p_scale_
+   \edef\p_scale      {\scaleparameter\c!scale      }%
+   \edef\p_xscale     {\scaleparameter\c!xscale     }%
+   \edef\p_yscale     {\scaleparameter\c!yscale     }%
+   \edef\p_width      {\scaleparameter\c!width      }%
+   \edef\p_height     {\scaleparameter\c!height     }%
+   \edef\p_depth      {\scaleparameter\c!depth      }%
+   \edef\p_lines      {\scaleparameter\c!lines      }%
+   \edef\p_factor     {\scaleparameter\c!factor     }%
+   \edef\p_hfactor    {\scaleparameter\c!hfactor    }%
+   \edef\p_wfactor    {\scaleparameter\c!wfactor    }%
+ % \edef\p_grid       {\scaleparameter\c!grid       }% used once
+   \edef\p_maxwidth   {\scaleparameter\c!maxwidth   }%
+   \edef\p_maxheight  {\scaleparameter\c!maxheight  }%
+   \edef\p_sx         {\scaleparameter\c!sx         }%
+   \edef\p_sy         {\scaleparameter\c!sy         }%
+   \edef\p_equalwidth {\scaleparameter\c!equalwidth }%
+   \edef\p_equalheight{\scaleparameter\c!equalheight}%
+   %
+   \d_grph_scale_dp\dp\nextbox
+   \ifx\p_depth\v!no \ifzeropt\d_grph_scale_dp \else
+     \setbox\nextbox\hpack{\raise\d_grph_scale_dp\box\nextbox}% new
+     \d_grph_scale_dp\dp\nextbox
+   \fi \fi
+   \d_grph_scale_wd\wd\nextbox
+   \d_grph_scale_ht\ht\nextbox
+   \d_grph_scale_dp\dp\nextbox
+   %
+   \global\let\finalscaleboxxscale \!!plusone
+   \global\let\finalscaleboxyscale \!!plusone
+   \xdef      \finalscaleboxwidth {\the\d_grph_scale_wd}%
+   \xdef      \finalscaleboxheight{\the\d_grph_scale_ht}%
+   %
+   \forgetall
+   \dontcomplain
+   %
+   \setfalse\c_grph_scale_done
+   \grph_scale_calculate
+   \ifconditional\c_grph_scale_done
+     \grph_scale_apply
+   \fi
+   \grph_scale_position
+   %
+   \box\nextbox
+   \egroup}
+
+\def\grph_scale_apply
+  {\d_grph_scale_wd\finalscaleboxxscale\d_grph_scale_wd
+   \d_grph_scale_ht\finalscaleboxyscale\d_grph_scale_ht
+   \d_grph_scale_dp\finalscaleboxyscale\d_grph_scale_dp
+   \setbox\nextbox\hpack
+     {\dostartscaling \finalscaleboxxscale \finalscaleboxyscale
+      \smashedbox\nextbox
+      \dostopscaling}%
+   \wd\nextbox\d_grph_scale_wd
+   \ht\nextbox\d_grph_scale_ht
+   \dp\nextbox\d_grph_scale_dp}
+
+\def\m_grph_scale_stamp_c{11}
+
+\def\grph_scale_calculate
+  {\ifdim\d_grph_scale_ht>\zeropoint \ifdim\d_grph_scale_wd>\zeropoint
+     \edef\m_grph_scale_stamp_a{\p_scale\p_xscale\p_yscale\p_factor\p_wfactor\p_hfactor\p_lines\p_width\p_height}%
+     \edef\m_grph_scale_stamp_b{\p_sx\p_sy}%
+     \ifx\m_grph_scale_stamp_a\empty
+       \ifx\m_grph_scale_stamp_b\m_grph_scale_stamp_c
+         % no scaling, don't change this (previous attempts failed anyway)
+         \insidefloattrue % trick
+         \grph_scale_calculations_yes
+       \else
+         \grph_scale_check_sx_sy
+         \grph_scale_calculations_nop
+       \fi
+     \else
+       \ifx\m_grph_scale_stamp_b\empty
+         % no need to check further
+       \else
+         \grph_scale_check_sx_sy
+       \fi
+       \grph_scale_calculations_yes
+     \fi
+   \fi \fi}
+
+\def\grph_scale_check_sx_sy
+  {\ifdim\p_sx\onepoint=\onepoint\else\edef\p_width {\the\dimexpr\p_sx\d_grph_scale_wd}\fi
+   \ifdim\p_sy\onepoint=\onepoint\else\edef\p_height{\the\dimexpr\p_sy\d_grph_scale_ht}\fi}
+
+\def\grph_scale_rounded#1%
+  {\expandafter\expandafter\expandafter\grph_scale_rounded_indeed
+     \expandafter\WITHOUTPT\the\dimexpr#1\points*100+32768\scaledpoint\relax.\relax}
+
+\def\grph_scale_rounded_indeed#1.#2\relax{#1}
+
+\def\grph_scale_calculations_nop
+  {\settrue\c_grph_scale_done
+   \xdef\finalscaleboxwidth {\the\dimexpr\p_sx\d_grph_scale_wd\relax}%
+   \xdef\finalscaleboxheight{\the\dimexpr\p_sy\d_grph_scale_ht\relax}%
+   \glet\finalscaleboxxscale\p_sx
+   \glet\finalscaleboxyscale\p_sy
+   \ifx\finalscaleboxxscale\empty\let\finalscaleboxxscale\!!plusone\fi
+   \ifx\finalscaleboxyscale\empty\let\finalscaleboxyscale\!!plusone\fi}
+
+\let\grph_scale_calculations_report\relax
+
+% \def\grph_scale_calculations_report
+%   {\writestatus
+%      {scaled}%
+%      {wd:\finalscaleboxwidth,ht:\finalscaleboxheight
+%      ,xscale:\finalscaleboxxscale,yscale:\finalscaleboxyscale}}
+
+% \def\grph_scale_calculations_yes
+%   {\settrue\c_grph_scale_done
+%    % initial values
+%    \d_grph_scale_x_offset\zeropoint
+%    \d_grph_scale_y_offset\zeropoint
+%    \d_grph_scale_x_size  \d_grph_scale_wd
+%    \d_grph_scale_y_size  \d_grph_scale_ht % alleen ht wordt geschaald!
+%    % final values
+%    \global\d_grph_scale_used_x_size \zeropoint % see note * (core-fig)
+%    \global\d_grph_scale_used_y_size \zeropoint % see note * (core-fig)
+%    \c_grph_scale_used_x_scale       \plusone   % see note * (core-fig)
+%    \c_grph_scale_used_y_scale       \plusone   % see note * (core-fig)
+%    \let\m_grph_scale_used_x_scale   \!!plusone
+%    \let\m_grph_scale_used_y_scale   \!!plusone
+%    % preparations
+%    \setfalse\c_grph_scale_scaling_done
+%    \grph_scale_check_parameters
+%    % calculators
+%    % beware, they operate in sequence, and calculate missing dimensions / messy
+%    % grph_scale_by_nature % when? needed?
+%    \ifconditional\c_grph_scale_scaling_done\else\grph_scale_by_factor   \fi
+%    \ifconditional\c_grph_scale_scaling_done\else\grph_scale_by_scale    \fi
+%    \ifconditional\c_grph_scale_scaling_done\else\grph_scale_by_dimension\fi
+%    % used in actual scaling
+%    \xdef\finalscaleboxwidth  {\the\d_grph_scale_used_x_size}%
+%    \xdef\finalscaleboxheight {\the\d_grph_scale_used_y_size}%
+%    \xdef\finalscaleboxxscale {\luaexpr{\number\c_grph_scale_used_x_scale/1000}}%
+%    \xdef\finalscaleboxyscale {\luaexpr{\number\c_grph_scale_used_y_scale/1000}}%
+%    \grph_scale_calculations_report}
+
+\def\grph_scale_calculations_yes
+  {\settrue\c_grph_scale_done
+   % initial values
+   \d_grph_scale_x_offset\zeropoint
+   \d_grph_scale_y_offset\zeropoint
+   \d_grph_scale_x_size  \d_grph_scale_wd
+   \d_grph_scale_y_size  \d_grph_scale_ht % alleen ht wordt geschaald!
+   % final values
+   \global\d_grph_scale_used_x_size \zeropoint % see note * (core-fig)
+   \global\d_grph_scale_used_y_size \zeropoint % see note * (core-fig)
+   \c_grph_scale_used_x_scale       \plusone   % see note * (core-fig)
+   \c_grph_scale_used_y_scale       \plusone   % see note * (core-fig)
+   \let\m_grph_scale_used_x_scale   \!!plusone
+   \let\m_grph_scale_used_y_scale   \!!plusone
+   % preparations
+   \setfalse\c_grph_scale_scaling_done
+   \grph_scale_check_parameters
+   % calculators
+   % beware, they operate in sequence, and calculate missing dimensions / messy
+   % grph_scale_by_nature % when? needed?
+   \ifconditional\c_grph_scale_scaling_done\else\grph_scale_by_factor   \fi
+   \ifconditional\c_grph_scale_scaling_done\else\grph_scale_by_scale    \fi
+   \ifconditional\c_grph_scale_scaling_done\else\grph_scale_by_dimension\fi
+   % used in actual scaling
+   \xdef\finalscaleboxwidth  {\the\d_grph_scale_used_x_size}%
+   \xdef\finalscaleboxheight {\the\d_grph_scale_used_y_size}%
+   \glet\finalscaleboxxscale \m_grph_scale_used_x_scale
+   \glet\finalscaleboxyscale \m_grph_scale_used_y_scale
+   \grph_scale_calculations_report}
+
+\setvalue{\??scalegrid\v!yes     }{\getnoflines   \d_grph_scale_used_y_size\edef\p_height{\the\noflines\lineheight}}
+\setvalue{\??scalegrid\v!height  }{\getrawnoflines\d_grph_scale_used_y_size\edef\p_height{\the\dimexpr\noflines\lineheight+\strutdepth}}
+\setvalue{\??scalegrid\v!depth   }{\getrawnoflines\d_grph_scale_used_y_size\edef\p_height{\the\dimexpr\noflines\lineheight-\strutdepth}}
+\setvalue{\??scalegrid\v!halfline}{\getrawnoflines\d_grph_scale_used_y_size\edef\p_height{\the\dimexpr\noflines\lineheight+.5\lineheight}}
+\setvalue{\??scalegrid\v!fit     }{\getrawnoflines\d_grph_scale_used_y_size\edef\p_height{\the\noflines\lineheight}}
+\letvalue{\??scalegrid\empty     }\donothing
+
+\def\grph_scale_check_parameters % resolve self referencing loops
+  {\ifx\p_maxwidth \empty\else \edef\p_maxwidth {\the\dimexpr\p_maxwidth        }\fi
+   \ifx\p_maxheight\empty\else \edef\p_maxheight{\the\dimexpr\p_maxheight       }\fi
+   \ifx\p_lines    \empty\else \edef\p_height   {\the\dimexpr\p_lines\lineheight}\fi
+   \csname\??scalegrid\scaleparameter\c!grid\endcsname}
+
+\def\grph_scale_by_nature % where ! ! ! ! !
+  {\ifx\p_width \empty\else \global\d_grph_scale_used_x_size\p_width \fi
+   \ifx\p_height\empty\else \global\d_grph_scale_used_y_size\p_height\fi
+   \ifx\p_scale \empty\else        \c_grph_scale_used_x_scale\p_scale
+                                   \c_grph_scale_used_y_scale\p_scale \fi
+   \ifx\p_xscale\empty\else        \c_grph_scale_used_x_scale\p_xscale\fi
+   \ifx\p_yscale\empty\else        \c_grph_scale_used_y_scale\p_yscale\fi}
+
+% \defineexternalfigure[width-6][factor=auto,maxwidth=\textheight,maxheight=\textwidth]
+% \defineexternalfigure[width-7][factor=auto,maxwidth=\textwidth,maxheight=\textheight]
+% \placefigure{none}{\rotate[frame=on,offset=overlay]{\externalfigure[t:/sources/cow.pdf][width-6]}} \page
+% \placefigure{none}{\framed[frame=on,offset=overlay]{\externalfigure[t:/sources/cow.pdf][width-7]}}
+
+\def\m_grph_scale_factor_set{\v!max,\v!fit,\v!broad,\v!auto} % can be an \edef
+
+\def\grph_scale_by_factor
+  {\doifelseinset\p_factor\m_grph_scale_factor_set
+     \grph_scale_by_factor_a
+     {\doifelseinset\p_hfactor\m_grph_scale_factor_set
+        \grph_scale_by_factor_b
+        {\doifelseinset\p_wfactor\m_grph_scale_factor_set
+           \grph_scale_by_factor_c
+           \grph_scale_by_factor_d}}}
+
+% \def\grph_scale_by_factor_a
+%   {\grph_scale_apply_size
+%    \ifdim\d_grph_scale_x_size>\d_grph_scale_y_size
+%      \grph_scale_calculate_norm  \d_grph_scale_used_x_size\p_factor\p_maxwidth\hsize\d_grph_scale_h_size
+%      \grph_scale_calculate_scales\d_grph_scale_used_x_size\d_grph_scale_x_size\d_grph_scale_used_y_size\d_grph_scale_y_size
+%    \else
+%      \grph_scale_calculate_norm  \d_grph_scale_used_y_size\p_factor\p_maxheight\d_grph_scale_outer_v_size\d_grph_scale_v_size
+%      \grph_scale_calculate_scales\d_grph_scale_used_y_size\d_grph_scale_y_size\d_grph_scale_used_x_size\d_grph_scale_x_size
+%    \fi
+%    \grph_scale_by_factor_indeed}
+%
+% \def\grph_scale_by_factor_b
+%   {\grph_scale_apply_size
+%    \grph_scale_calculate_norm  \d_grph_scale_used_y_size\p_hfactor\p_maxheight\d_grph_scale_outer_v_size\d_grph_scale_v_size
+%    \grph_scale_calculate_scales\d_grph_scale_used_y_size\d_grph_scale_y_size\d_grph_scale_used_x_size\d_grph_scale_x_size
+%    \grph_scale_by_factor_indeed}
+%
+% \def\grph_scale_by_factor_c
+%   {\grph_scale_apply_size
+%    \grph_scale_calculate_norm  \d_grph_scale_used_x_size\p_wfactor\p_maxwidth\hsize\d_grph_scale_h_size
+%    \grph_scale_calculate_scales\d_grph_scale_used_x_size\d_grph_scale_x_size\d_grph_scale_used_y_size\d_grph_scale_y_size
+%    \grph_scale_by_factor_indeed}
+%
+% \def\grph_scale_by_factor_d
+%   {\grph_scale_calculate_norm\d_grph_scale_used_y_size\p_factor \p_height \textheight\d_grph_scale_v_size
+%    \grph_scale_calculate_norm\d_grph_scale_used_y_size\p_hfactor\p_height \textheight\d_grph_scale_v_size
+%    \grph_scale_calculate_norm\d_grph_scale_used_x_size\p_wfactor\p_width  \hsize     \hsize}
+
+\def\grph_scale_by_factor_a
+  {\grph_scale_apply_size
+   \ifdim\d_grph_scale_x_size>\d_grph_scale_y_size
+     \grph_scale_calculate_norm  \d_grph_scale_used_x_size\p_factor\p_maxwidth\hsize\d_grph_scale_h_size
+     \grph_scale_calculate_scales\d_grph_scale_used_x_size\d_grph_scale_x_size
+     \d_grph_scale_used_y_size\m_grph_scale_used_x_scale\d_grph_scale_y_size
+   \else
+     \grph_scale_calculate_norm  \d_grph_scale_used_y_size\p_factor\p_maxheight\d_grph_scale_outer_v_size\d_grph_scale_v_size
+     \grph_scale_calculate_scales\d_grph_scale_used_y_size\d_grph_scale_y_size
+     \d_grph_scale_used_x_size\m_grph_scale_used_x_scale\d_grph_scale_x_size
+   \fi
+   \grph_scale_by_factor_indeed}
+
+\def\grph_scale_by_factor_b
+  {\grph_scale_apply_size
+   \grph_scale_calculate_norm  \d_grph_scale_used_y_size\p_hfactor\p_maxheight\d_grph_scale_outer_v_size\d_grph_scale_v_size
+   \grph_scale_calculate_scales\d_grph_scale_used_y_size\d_grph_scale_y_size
+   \d_grph_scale_used_x_size\m_grph_scale_used_x_scale\d_grph_scale_x_size
+   \grph_scale_by_factor_indeed}
+
+\def\grph_scale_by_factor_c
+  {\grph_scale_apply_size
+   \grph_scale_calculate_norm  \d_grph_scale_used_x_size\p_wfactor\p_maxwidth\hsize\d_grph_scale_h_size
+   \grph_scale_calculate_scales\d_grph_scale_used_x_size\d_grph_scale_x_size
+   \d_grph_scale_used_y_size\m_grph_scale_used_x_scale\d_grph_scale_y_size
+   \grph_scale_by_factor_indeed}
+
+\def\grph_scale_by_factor_d
+  {\grph_scale_calculate_norm\d_grph_scale_used_y_size\p_factor \p_height \textheight\d_grph_scale_v_size
+   \grph_scale_calculate_norm\d_grph_scale_used_y_size\p_hfactor\p_height \textheight\d_grph_scale_v_size
+   \grph_scale_calculate_norm\d_grph_scale_used_x_size\p_wfactor\p_width  \hsize     \hsize}
+
+\def\grph_scale_by_factor_indeed
+  {\settrue\c_grph_scale_scaling_done
+   \ifconditional\c_grph_scale_limit_factors
+     \ifdim\d_grph_scale_used_x_size>\d_grph_scale_h_size
+       \global\d_grph_scale_used_y_size\zeropoint
+       \global\d_grph_scale_used_x_size\d_grph_scale_h_size
+     \else\ifdim\d_grph_scale_used_y_size>\d_grph_scale_v_size
+       \global\d_grph_scale_used_x_size\zeropoint
+       \global\d_grph_scale_used_y_size\d_grph_scale_v_size
+     \fi\fi
+   \fi
+   \grph_scale_by_dimension}
+
+% \def\grph_scale_by_scale
+%   {\edef\m_grph_scale_temp{\p_scale\p_xscale\p_yscale}%
+%    \ifx\m_grph_scale_temp\empty \else
+%      \grph_scale_apply_scale\d_grph_scale_used_x_size\d_grph_scale_x_size\c_grph_scale_used_x_scale\p_xscale
+%      \grph_scale_apply_scale\d_grph_scale_used_y_size\d_grph_scale_y_size\c_grph_scale_used_y_scale\p_yscale
+%      \global\d_grph_scale_used_x_size\zeropoint
+%      \global\d_grph_scale_used_y_size\zeropoint
+%      \ifx\p_maxwidth\empty
+%        \ifx\p_maxheight\empty
+%        \else
+%          \ifdim\d_grph_scale_y_size>\p_maxheight\relax
+%            \global\d_grph_scale_used_y_size\p_maxheight
+%          \fi
+%        \fi
+%      \else
+%        \ifdim\d_grph_scale_x_size>\p_maxwidth\relax
+%           \global\d_grph_scale_used_x_size\p_maxwidth
+%        \fi
+%      \fi
+%    \fi}
+
+\def\grph_scale_by_scale
+  {\edef\m_grph_scale_temp{\p_scale\p_xscale\p_yscale}%
+   \ifx\m_grph_scale_temp\empty \else
+     \grph_scale_apply_scale\m_grph_scale_used_x_scale\p_xscale
+     \grph_scale_apply_scale\m_grph_scale_used_y_scale\p_yscale
+   % \global\d_grph_scale_used_x_size\m_grph_scale_used_x_scale\d_grph_scale_x_size\relax % no global needed here
+   % \global\d_grph_scale_used_y_size\m_grph_scale_used_y_scale\d_grph_scale_y_size\relax % no global needed here
+     % wrong: we need to recalculate the scale
+     \global\d_grph_scale_used_x_size\zeropoint
+     \global\d_grph_scale_used_y_size\zeropoint
+     %
+     \ifx\p_maxwidth\empty
+       \ifx\p_maxheight\empty
+       \else
+         \ifdim\d_grph_scale_y_size>\p_maxheight\relax
+           \global\d_grph_scale_used_y_size\p_maxheight
+         \fi
+       \fi
+     \else
+       \ifdim\d_grph_scale_x_size>\p_maxwidth\relax
+          \global\d_grph_scale_used_x_size\p_maxwidth
+       \fi
+     \fi
+   \fi}
+
+\def\grph_scale_by_dimension
+  {\ifdim\d_grph_scale_used_x_size>\zeropoint
+     \ifdim\d_grph_scale_used_y_size>\zeropoint
+       \grph_scale_by_dimension_a
+     \else
+       \grph_scale_by_dimension_b
+     \fi
+   \else
+     \ifdim\d_grph_scale_used_y_size>\zeropoint
+       \grph_scale_by_dimension_c
+     \else
+       \grph_scale_by_dimension_d
+     \fi
+   \fi}
+
+% \def\grph_scale_by_dimension_a
+%   {\grph_scale_by_dimension_indeed
+%      {\grph_scale_calculate_scale\d_grph_scale_used_y_size\d_grph_scale_y_size\c_grph_scale_used_y_scale
+%       \grph_scale_calculate_scale\d_grph_scale_used_x_size\d_grph_scale_x_size\c_grph_scale_used_x_scale}%
+%      {\grph_scale_calculate_scale\d_grph_scale_used_y_size\d_grph_scale_y_size\c_grph_scale_used_y_scale
+%       \grph_scale_calculate_scale\d_grph_scale_used_x_size\d_grph_scale_x_size\c_grph_scale_used_x_scale}%
+%      {\grph_scale_calculate_scale\d_grph_scale_used_y_size\d_grph_scale_y_size\c_grph_scale_used_y_scale
+%       \grph_scale_calculate_scale\d_grph_scale_used_x_size\d_grph_scale_x_size\c_grph_scale_used_x_scale}}
+%
+% \def\grph_scale_by_dimension_b
+%   {\grph_scale_by_dimension_indeed
+%      {\grph_scale_calculate_scales\d_grph_scale_used_x_size\d_grph_scale_x_size\d_grph_scale_used_y_size\d_grph_scale_y_size}%
+%      {\grph_scale_calculate_scales\d_grph_scale_used_x_size\d_grph_scale_x_size\d_grph_scale_used_y_size\d_grph_scale_y_size}%
+%      {\grph_scale_calculate_scales\d_grph_scale_used_x_size\d_grph_scale_x_size\d_grph_scale_used_y_size\d_grph_scale_y_size}}
+%
+% \def\grph_scale_by_dimension_c
+%   {\grph_scale_by_dimension_indeed
+%      {\grph_scale_calculate_scales\d_grph_scale_used_y_size\d_grph_scale_y_size\d_grph_scale_used_x_size\d_grph_scale_x_size}%
+%      {\grph_scale_calculate_scales\d_grph_scale_used_y_size\d_grph_scale_y_size\d_grph_scale_used_x_size\d_grph_scale_x_size}%
+%      {\grph_scale_calculate_scales\d_grph_scale_used_y_size\d_grph_scale_y_size\d_grph_scale_used_x_size\d_grph_scale_x_size}}
+%
+% \def\grph_scale_by_dimension_d
+%   {\grph_scale_by_dimension_indeed
+%      {\grph_scale_apply_scale\d_grph_scale_used_x_size\d_grph_scale_x_size\c_grph_scale_used_x_scale\p_xscale
+%       \grph_scale_apply_scale\d_grph_scale_used_y_size\d_grph_scale_y_size\c_grph_scale_used_y_scale\p_yscale}%
+%      {\grph_scale_calculate_scales\d_grph_scale_used_x_size\d_grph_scale_x_size\d_grph_scale_used_y_size\d_grph_scale_y_size}%
+%      {\grph_scale_calculate_scales\d_grph_scale_used_y_size\d_grph_scale_y_size\d_grph_scale_used_x_size\d_grph_scale_x_size}}
+
+\def\grph_scale_by_dimension_a
+  {\grph_scale_by_dimension_indeed
+     {\grph_scale_calculate_scale\m_grph_scale_used_y_scale\d_grph_scale_used_y_size\d_grph_scale_y_size
+      \grph_scale_calculate_scale\m_grph_scale_used_x_scale\d_grph_scale_used_x_size\d_grph_scale_x_size}%
+     {\grph_scale_calculate_scale\m_grph_scale_used_y_scale\d_grph_scale_used_y_size\d_grph_scale_y_size
+      \grph_scale_calculate_scale\m_grph_scale_used_x_scale\d_grph_scale_used_x_size\d_grph_scale_x_size}%
+     {\grph_scale_calculate_scale\m_grph_scale_used_y_scale\d_grph_scale_used_y_size\d_grph_scale_y_size
+      \grph_scale_calculate_scale\m_grph_scale_used_x_scale\d_grph_scale_used_x_size\d_grph_scale_x_size}}
+
+\def\grph_scale_by_dimension_b
+  {\grph_scale_by_dimension_indeed
+     {\grph_scale_calculate_scales\d_grph_scale_used_x_size\d_grph_scale_x_size
+      \d_grph_scale_used_y_size\m_grph_scale_used_x_scale\d_grph_scale_y_size}%
+     {\grph_scale_calculate_scales\d_grph_scale_used_x_size\d_grph_scale_x_size
+      \d_grph_scale_used_y_size\m_grph_scale_used_x_scale\d_grph_scale_y_size}%
+     {\grph_scale_calculate_scales\d_grph_scale_used_x_size\d_grph_scale_x_size
+      \d_grph_scale_used_y_size\m_grph_scale_used_x_scale\d_grph_scale_y_size}}
+
+\def\grph_scale_by_dimension_c
+  {\grph_scale_by_dimension_indeed % weird .. three same cases
+     {\grph_scale_calculate_scales\d_grph_scale_used_y_size\d_grph_scale_y_size
+      \d_grph_scale_used_x_size\m_grph_scale_used_x_scale\d_grph_scale_x_size}%
+     {\grph_scale_calculate_scales\d_grph_scale_used_y_size\d_grph_scale_y_size
+      \d_grph_scale_used_x_size\m_grph_scale_used_x_scale\d_grph_scale_x_size}%
+     {\grph_scale_calculate_scales\d_grph_scale_used_y_size\d_grph_scale_y_size
+      \d_grph_scale_used_x_size\m_grph_scale_used_x_scale\d_grph_scale_x_size}}
+
+\def\grph_scale_by_dimension_d
+  {\grph_scale_by_dimension_indeed
+     {\grph_scale_apply_scale\m_grph_scale_used_x_scale\p_xscale
+      \grph_scale_apply_scale\m_grph_scale_used_y_scale\p_yscale
+      \global\d_grph_scale_used_x_size\m_grph_scale_used_x_scale\d_grph_scale_x_size
+      \global\d_grph_scale_used_y_size\m_grph_scale_used_y_scale\d_grph_scale_y_size}%
+     {\grph_scale_calculate_scales\d_grph_scale_used_x_size\d_grph_scale_x_size
+      \d_grph_scale_used_y_size\m_grph_scale_used_x_scale\d_grph_scale_y_size}%
+     {\grph_scale_calculate_scales\d_grph_scale_used_y_size\d_grph_scale_y_size
+      \d_grph_scale_used_x_size\m_grph_scale_used_x_scale\d_grph_scale_x_size}}
+
+\def\grph_scale_by_dimension_indeed#1#2#3%
+  {#1\relax
+   \ifx\p_maxwidth\empty \else
+     \ifdim\d_grph_scale_used_x_size>\p_maxwidth\relax
+       \global\d_grph_scale_used_x_size\p_maxwidth
+       #2\relax
+     \fi
+   \fi
+   \ifx\p_maxheight\empty \else
+     \ifdim\d_grph_scale_used_y_size>\p_maxheight\relax
+       \global\d_grph_scale_used_y_size\p_maxheight
+        #3\relax
+     \fi
+   \fi}
+
+\def\grph_scale_calculate_norm#1#2% todo: swap 1 and 2 and pass one less
+  {\csname\??scalenorm\ifcsname\??scalenorm#2\endcsname#2\else\s!unknown\fi\endcsname#1#2}
+
+\setvalue{\??scalenorm\v!max    }#1#2#3#4#5{\global#1#4}
+\setvalue{\??scalenorm\v!fit    }#1#2#3#4#5{\global#1#5}
+\setvalue{\??scalenorm\v!broad  }#1#2#3#4#5{\global#1\dimexpr#5-4\externalfigureparameter\c!bodyfont\relax}
+\setvalue{\??scalenorm\s!unknown}#1#2#3#4#5{\global#1\dimexpr#2\dimexpr\externalfigureparameter\c!bodyfont/10\relax\relax} % brr ex
+\setvalue{\??scalenorm\v!auto   }#1#2#3#4#5{\ifx#3\empty\else\global#1#3\fi}
+\setvalue{\??scalenorm\empty    }#1#2#3#4#5{\ifx#3\empty\else\global#1#3\fi}
+\setvalue{\??scalenorm\s!default}#1#2#3#4#5{\ifx#3\empty\else\global#1#3\fi}
+
+% \def\grph_scale_calculate_scales#1#2#3#4%
+%   {\scratchdimen\dimexpr#1/\dimexpr#2/\plusthousand\relax\relax
+%    \c_grph_scale_used_x_scale\scratchdimen
+%    \c_grph_scale_used_y_scale\scratchdimen
+%   %\writestatus{!!!!}{\the#3/\luaexpr{\number\dimexpr#1\relax/\number\dimexpr#2/1000}}%
+%    #3\dimexpr\c_grph_scale_used_x_scale\dimexpr#4/\plusthousand\relax\relax}
+%
+% \def\grph_scale_calculate_scale#1#2#3%
+%   {#3\dimexpr#1/\dimexpr#2/\plusthousand\relax\relax}
+%
+% \def\grph_scale_apply_scale#1#2#3#4% #4 = parameter / scale can be empty
+%   {\ifcase0#4\relax
+%      \ifcase0\p_scale\relax
+%        #3=\plusthousand
+%      \else
+%        #3=\p_scale
+%      \fi
+%    \else
+%      #3=#4%
+%    \fi
+%    \relax % important ! still ?
+%    \global#1\ifnum#3=\plusthousand#2\else\dimexpr#3\dimexpr#2/\plusthousand\relax\relax\fi
+%    \relax}
+
+\def\grph_scale_calculate_scales#1#2%
+  {\edef\m_grph_scale_used_x_scale{\luaexpr{\number#1/\number#2}}%
+   \let\m_grph_scale_used_y_scale\m_grph_scale_used_x_scale}
+
+% we could inline this:
+%
+% \grph_scale_calculate_scale\m_grph_scale_used_x_scale#1#2
+% \let\m_grph_scale_used_y_scale\m_grph_scale_used_x_scale
+
+\def\grph_scale_calculate_scale#1#2#3%
+  {\edef#1{\luaexpr{\number#2/\number#3}}}
+
+\def\grph_scale_apply_scale#1#2% #1 = parameter / scale can be empty
+  {\edef#1{\luaexpr
+     {\number
+      \ifx#2\empty
+        \ifx  \p_scale \empty     \plusthousand \else
+        \ifnum\p_scale=\zerocount \plusthousand \else
+                                  \p_scale      \fi\fi
+      \else\ifnum#2=\zerocount
+        \ifx  \p_scale \empty     \plusthousand \else
+        \ifnum\p_scale=\zerocount \plusthousand \else
+                                  \p_scale      \fi\fi
+      \else
+                                  #2%
+      \fi\fi
+      /1000}}}
+
+\def\grph_scale_apply_size
+  {\ifx\p_maxheight\empty
+     \d_grph_scale_outer_v_size\textheight
+     \ifinner
+       \d_grph_scale_outer_v_size \vsize % \textheight =\vsize
+       \scratchdimen\vsize % \scratchdimen=\textheight
+     \else\ifinsidefloat
+       \d_grph_scale_outer_v_size \vsize % \textheight =\vsize
+       \scratchdimen\vsize % \scratchdimen=\textheight
+     \else\ifinpagebody
+       \d_grph_scale_outer_v_size \vsize % \textheight =\vsize
+       \scratchdimen\vsize % \scratchdimen=\textheight
+     \else % hm, there should be an option to force this
+       \ifdim\pagegoal<\maxdimen
+         \ifdim\pagetotal<\pagegoal
+           \scratchdimen\dimexpr\pagegoal-\pagetotal\relax
+         \else
+           \scratchdimen\d_grph_scale_outer_v_size % \textheight
+         \fi
+       \else
+         \scratchdimen\d_grph_scale_outer_v_size % \textheight
+       \fi
+     \fi\fi\fi
+   \else
+     \scratchdimen\p_maxheight
+     \d_grph_scale_outer_v_size\scratchdimen
+   \fi
+   \ifx\p_height\empty
+     \d_grph_scale_v_size\scratchdimen
+   \else
+     \d_grph_scale_v_size\p_height
+   \fi
+   \ifx\p_width\empty
+     \d_grph_scale_h_size\hsize
+   \else
+     \d_grph_scale_h_size\p_width
+   \fi}
+
+%\def\grph_scale_convert_large_scale#1#2#3#4%
+%  {\scratchdimen#1\relax
+%   \ifnum#3=\plusthousand
+%     % == scale 1
+%   \else
+%     % better 1000 100 10 ranges, evt round 2sp
+%     \divide\scratchdimen \plusthousand
+%     \multiply\scratchdimen #3\relax
+%   \fi
+%   \scratchdimen-\scratchdimen  % beter hier - dan in driver
+%   \edef#2{\the\scratchdimen}%
+%   \scratchcounter#3\relax
+%   \ifnum\scratchcounter>\plustenthousand
+%     \divide\scratchcounter\plusten
+%     \scratchdimen\the\scratchcounter\points % \the ?
+%   \else
+%     \scratchdimen\the\scratchcounter\points % \the ?
+%     \divide\scratchdimen\plusten
+%   \fi
+%   \edef#4{\withoutpt\the\scratchdimen}}
+%
+% \def\grph_scale_convert_large_scale#1#2#3#4% less overflow
+%   {\edef#2{\ifnum#3=\plusthousand-\the\dimexpr#1\else\luaexpr{-\number#3*\number\dimexpr#1/1000}sp\fi}%
+%    \edef#4{\luaexpr{\number#3/10}}}
+
+% \startcombination
+%     {\externalfigure[cow.pdf] [frame=on,height=3cm,equalwidth=6cm]} {a cow}
+%     {\externalfigure[mill.png][frame=on,height=3cm,equalwidth=6cm]} {a mill}
+% \stopcombination
+
+\def\grph_scale_position
+  {\ifx\p_equalwidth\empty \else
+    \scratchdimen\p_equalwidth\relax
+    \ifdim\d_grph_scale_wd<\scratchdimen
+      \setbox\nextbox\hpack to \scratchdimen{\hss\box\nextbox\hss}%
+    \fi
+   \fi
+   \ifx\p_equalheight\empty \else
+     \scratchdimen\p_equalheight\relax
+     \ifdim\d_grph_scale_ht<\scratchdimen
+       \setbox\nextbox\vpack to \scratchdimen{\vss\box\nextbox\vss}%
+     \fi
+   \fi}
+
+\unexpanded\def\fastscale#1%
+  {\ifnum#1=1000\relax
+     \expandafter\grph_scale_fast_nop
+   \else
+     \expandafter\grph_scale_fast_yes
+   \fi{#1}}
+
+\def\grph_scale_fast_nop#1%
+  {\hbox}
+
+\def\grph_scale_fast_yes#1%
+  {\edef\finalscaleboxxscale{\withoutpt\the\dimexpr#1\onepoint/1000\relax}% brrr
+   \let\finalscaleboxyscale\finalscaleboxxscale
+   \dowithnextboxcs\grph_scale_fast_finish\hbox}
+
+\def\grph_scale_fast_finish
+  {\grph_scale_apply
+   \box\nextbox
+   \endgroup}
+
+\unexpanded\def\fastsxsy#1#2%
+  {\bgroup
+   \edef\p_sx{#1}%
+   \edef\p_sy{#2}%
+   \dowithnextboxcs\grph_scale_fast_sx_xy_finish\hbox}
+
+\def\grph_scale_fast_sx_xy_finish
+  {\grph_scale_check_sx_sy
+   \grph_scale_calculations_nop
+   \grph_scale_apply
+   \box\nextbox
+   \egroup}
+
+%D \macros
+%D   {clip, setupclipping}
+%D
+%D Although related to figures, clipping can be applied to
+%D arbitrary content. We can use \METAPOST\ to provide a non
+%D rectangular clipping path.
+%D
+%D \starttyping
+%D \startMPclip{fun}
+%D   clip currentpicture to fullcircle
+%D     shifted (.5,.5) xscaled \width yscaled \height ;
+%D \stopMPclip
+%D \stoptyping
+%D
+%D We get a rectangular piece of the figure when we say:
+%D
+%D \starttyping
+%D \clip[x=2,y=1]{\externalfigure[photo]}
+%D \stoptyping
+%D
+%D When we want to clip to the oval we defined a few lines ago,
+%D we say:
+%D
+%D \starttyping
+%D \clip[nx=1,ny=1,x=1,y=1,mp=fun]{\externalfigure[photo]}
+%D \stoptyping
+%D
+%D The general characteristics of clipping can be set up with
+%D
+%D \showsetup{setupclipping}
+
+\installcorenamespace{clipping}
+
+\installdirectcommandhandler \??clipping {clipping}
+
+\unexpanded\def\clip
+  {\dosingleempty\grph_clip}
+
+\def\grph_clip[#1]% nb top->bottom left->right
+  {\bgroup
+   \iffirstargument
+     \setupcurrentclipping[#1]%
+   \fi
+   \dowithnextboxcs\grph_clip_finish\hbox}
+
+\def\grph_clip_finish
+  {\doifelse{\clippingparameter\c!state}\v!start
+     \grph_clip_yes_finish
+     \grph_clip_nop_finish}
+
+% \def\grph_clip_yes_finish
+%   {\ifdim\@@cpwidth>\zeropoint
+%      \!!dimena\@@cpwidth
+%      \!!dimenc\@@cphoffset
+%    \else
+%      \!!dimena\wd\nextbox
+%      \divide\!!dimena \@@cpnx
+%      \!!dimenc\@@cpx\!!dimena
+%      \advance\!!dimenc -\!!dimena
+%      \!!dimena\@@cpsx\!!dimena
+%    \fi
+%    \relax % sure
+%    \ifdim\@@cpheight>\zeropoint
+%      \!!dimenb\@@cpheight
+%      \!!dimend\ht\nextbox
+%      \advance\!!dimend -\@@cpvoffset
+%      \advance\!!dimend -\!!dimenb
+%    \else
+%      \!!dimenb\ht\nextbox
+%      \divide\!!dimenb \@@cpny
+%      \!!dimend-\@@cpy\!!dimenb
+%      \advance\!!dimend -\@@cpsy\!!dimenb
+%      \advance\!!dimend \!!dimenb
+%      \!!dimenb\@@cpsy\!!dimenb
+%      \advance\!!dimend \ht\nextbox % dimend !
+%    \fi
+%    \setbox\nextbox\hbox                            % old
+%      {\advance\!!dimenc -\@@cpleftoffset           % new !
+%       \advance\!!dimend -\@@cpbottomoffset         % new ! % - added
+%       \hskip-\!!dimenc\lower\!!dimend\box\nextbox}% old
+%    \wd\nextbox\zeropoint
+%    \ht\nextbox\zeropoint
+%    \dp\nextbox\zeropoint
+%    \setbox\nextbox\hbox
+%      {\advance\!!dimena \@@cpleftoffset         % new !
+%       \advance\!!dimena \@@cprightoffset        % new !
+%       \advance\!!dimenb \@@cpbottomoffset       % new !
+%       \advance\!!dimenb \@@cptopoffset          % new !
+%       \dostartclipping\@@cpmp\!!dimena\!!dimenb % old
+%         \box\nextbox
+%       \dostopclipping}%
+%    \setbox\nextbox\hbox                       % new !
+%      {\!!dimena-\@@cpleftoffset               % new !
+%       \!!dimenb \@@cpbottomoffset             % new ! % - removed
+%       \hskip\!!dimena\lower\!!dimenb\box\nextbox}% new !
+%    \wd\nextbox\!!dimena
+%    \ht\nextbox\!!dimenb
+%    \dp\nextbox\zeropoint
+%    \box\nextbox
+%    \egroup}
+
+\def\grph_clip_yes_finish
+  {\ifdim\clippingparameter\c!width>\zeropoint
+     \scratchwidth  \clippingparameter\c!width
+     \scratchxoffset\clippingparameter\c!hoffset
+   \else
+     \scratchwidth\dimexpr\wd\nextbox/\clippingparameter\c!nx\relax
+     \scratchxoffset\dimexpr\clippingparameter\c!x\scratchwidth-\scratchwidth\relax
+     \scratchwidth\clippingparameter\c!sx\scratchwidth
+   \fi
+   \relax % sure
+   \ifdim\clippingparameter\c!height>\zeropoint
+     \scratchheight\clippingparameter\c!height
+     \scratchyoffset\dimexpr\ht\nextbox-\clippingparameter\c!voffset-\scratchheight\relax
+   \else
+     \scratchheight\dimexpr\ht\nextbox/\clippingparameter\c!ny\relax
+     \scratchyoffset\dimexpr-\clippingparameter\c!y\scratchheight-\clippingparameter\c!sy\scratchheight+\scratchheight\relax
+     \scratchheight\clippingparameter\c!sy\scratchheight
+     \advance\scratchyoffset \ht\nextbox
+   \fi
+   \setbox\nextbox\hpack
+     {\advance\scratchxoffset -\clippingparameter\c!leftoffset  \relax
+      \advance\scratchyoffset -\clippingparameter\c!bottomoffset\relax
+      \hskip-\scratchxoffset
+      \lower\scratchyoffset
+      \box\nextbox}%
+   \wd\nextbox\zeropoint
+   \ht\nextbox\zeropoint
+   \dp\nextbox\zeropoint
+   \setbox\nextbox\hpack
+     {\advance\scratchwidth \dimexpr\clippingparameter\c!leftoffset  +\clippingparameter\c!rightoffset\relax
+      \advance\scratchheight\dimexpr\clippingparameter\c!bottomoffset+\clippingparameter\c!topoffset  \relax
+      \dostartclipping{\clippingparameter\c!mp}\scratchwidth\scratchheight
+        \box\nextbox
+      \dostopclipping}%
+   \setbox\nextbox\hpack
+     {\hskip-\clippingparameter\c!leftoffset
+      \lower \clippingparameter\c!bottomoffset
+      \box\nextbox}%
+   \wd\nextbox\scratchwidth
+   \ht\nextbox\scratchheight
+   \dp\nextbox\zeropoint
+   \box\nextbox
+   \egroup}
+
+\def\grph_clip_nop_finish
+  {\box\nextbox
+   \egroup}
+
+\setupclipping
+  [\c!state=\v!start,
+   \c!n=\plusone, % was \plustwo
+   \c!nx=\clippingparameter\c!n,\c!x=\plusone,\c!sx=\plusone,
+   \c!ny=\clippingparameter\c!n,\c!y=\plusone,\c!sy=\plusone,
+   \c!width=\zeropoint,
+   \c!height=\zeropoint,
+   \c!hoffset=\zeropoint,
+   \c!voffset=\zeropoint,
+   \c!offset=\zeropoint,
+   \c!leftoffset=\clippingparameter\c!offset,
+   \c!rightoffset=\clippingparameter\c!offset,
+   \c!topoffset=\clippingparameter\c!offset,
+   \c!bottomoffset=\clippingparameter\c!offset,
+   \c!mp=]
+
+%D \startbuffer
+%D \startuseMPgraphic{test}
+%D   path p ; p := fullcircle scaled 4cm ;
+%D   draw p withpen pencircle scaled 1cm ;
+%D   setbounds currentpicture to boundingbox p ;
+%D \stopuseMPgraphic
+%D
+%D \hbox to \hsize \bgroup
+%D   \hss
+%D   \ruledhbox{\useMPgraphic{test}}%
+%D   \hss
+%D   \ruledhbox{\clip{\useMPgraphic{test}}}%
+%D   \hss
+%D \egroup
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+
+%D Mirroring.
+
+\unexpanded\def\mirror
+  {\bgroup
+   \dowithnextboxcs\grph_mirror_finish\hbox}
+
+\def\grph_mirror_finish
+  {\scratchdimen\wd\nextbox
+   % better use an hbox (if no \forgetall, leftskip etc may creep in)
+   %\setbox\nextbox\vbox{\forgetall\dostartmirroring\hskip-\wd\nextbox\box\nextbox\dostopmirroring}%
+   \setbox\nextbox\hpack{\dostartmirroring\hskip-\wd\nextbox\box\nextbox\dostopmirroring}%
+   \wd\nextbox\scratchdimen
+   \box\nextbox
+   \egroup}
+
+%D A couple of examples, demonstrating how the depth is
+%D taken care of:
+%D
+%D \startbuffer
+%D test\rotate[frame=on, rotation=0]  {gans}%
+%D test\rotate[frame=on, rotation=90] {gans}%
+%D test\rotate[frame=on, rotation=180]{gans}%
+%D test\rotate[frame=on, rotation=270]{gans}%
+%D test
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+
+% When we rotate over arbitrary angles, we need to relocate the
+% resulting box because rotation brings that box onto the negative
+% axis. The calculations (mostly sin and cosine) need to be tuned for
+% the way a box is packages (i.e. the refence point). A typical example
+% of drawing, scribbling, and going back to the days of school math.
+%
+% We do a bit more calculations than needed, simply because that way
+% it's easier to debug the code.
+
+% Cleanup in progress ... todo: less boxing
+
+\installcorenamespace {rotate}
+\installcorenamespace {rotatelocation}
+\installcorenamespace {rotatepreset}
+
+% we can alias these to \d_layers-* to save some dimens or maybe have a generic
+% set of scratch variables
+
+% maybe just \rotation_...
+
+\newdimen\d_grph_rotate_x_size
+\newdimen\d_grph_rotate_y_size
+\newdimen\d_grph_rotate_x_offset
+\newdimen\d_grph_rotate_y_offset
+\newdimen\d_grph_rotate_x_position
+\newdimen\d_grph_rotate_y_position
+
+\newdimen\d_grph_rotate_used_height
+
+\let\d_grph_rotate_width \!!widtha
+\let\d_grph_rotate_height\!!heighta
+\let\d_grph_rotate_depth \!!deptha
+
+\let\d_grph_rotate_saved_width \!!widthb
+\let\d_grph_rotate_saved_height\!!heightb
+\let\d_grph_rotate_saved_depth \!!depthb
+
+\newconditional\c_grph_rotate_obey_depth
+\newconditional\c_grph_rotate_not_fit
+\newconditional\c_grph_rotate_center
+
+\installframedcommandhandler \??rotate {rotate} \??rotate
+
+\setuprotate
+  [\c!rotation=90,
+   \c!location=\v!normal,
+   \c!width=\v!fit,
+   \c!height=\v!fit,
+   \c!offset=\v!overlay,
+   \c!frame=\v!off]
+
+\let\p_rotation_location\empty
+\let\p_rotation_rotation\empty
+
+\unexpanded\def\rotate % \bgroup: \rotate kan argument zijn
+  {\bgroup
+   \dosingleempty\grph_rotate}
+
+\def\grph_rotate[#1]%
+  {\iffirstargument
+     \setupcurrentrotate[#1]%
+   \fi
+   \edef\p_rotation_location{\rotateparameter\c!location}%
+   \edef\p_rotation_rotation{\rotateparameter\c!rotation}%
+   \csname\??rotatelocation
+     \ifcsname\??rotatelocation\p_rotation_location\endcsname\p_rotation_location\else\v!default\fi
+   \endcsname}
+
+\def\grph_rotate_framed
+  {\resetrotateparameter\c!location
+   \dowithnextboxcs\grph_rotate_finish\vbox
+   \inheritedrotateframed}
+
+\def\grph_rotate_normal
+  {\dowithnextboxcs\grph_rotate_finish\vbox}
+
+\def\grph_rotate_finish
+  {\grph_rotate_finish_indeed
+   \egroup}
+
+\setvalue{\??rotatelocation\v!depth}%
+  {\setfalse\c_grph_rotate_not_fit
+   \setfalse\c_grph_rotate_center
+   \settrue \c_grph_rotate_obey_depth
+   \grph_rotate_normal}
+
+\setvalue{\??rotatelocation\v!fit}%
+  {\settrue \c_grph_rotate_not_fit
+   \setfalse\c_grph_rotate_center
+   \settrue \c_grph_rotate_obey_depth
+   \grph_rotate_normal}
+
+\setvalue{\??rotatelocation\v!broad}%
+  {\setfalse\c_grph_rotate_not_fit
+   \setfalse\c_grph_rotate_center
+   \setfalse\c_grph_rotate_obey_depth
+   \grph_rotate_normal}
+
+\setvalue{\??rotatelocation\v!high}%
+  {\setfalse\c_grph_rotate_not_fit
+   \setfalse\c_grph_rotate_center
+   \setfalse\c_grph_rotate_obey_depth
+   \grph_rotate_framed}
+
+\setvalue{\??rotatelocation\v!middle}%
+  {\setfalse\c_grph_rotate_not_fit
+   \settrue \c_grph_rotate_center
+   \setfalse\c_grph_rotate_obey_depth  % hm, depth ?
+   \grph_rotate_normal}
+
+\setvalue{\??rotatelocation\v!default}%
+  {\setfalse\c_grph_rotate_not_fit
+   \setfalse\c_grph_rotate_center
+   \settrue \c_grph_rotate_obey_depth
+   \grph_rotate_framed}
+
+\unexpanded\def\dorotatebox#1% {angle} \hbox/\vbox/\vtop % a fast low level one
+  {\ifcase#1\relax
+     \expandafter\gobbleoneargument
+   \else
+     \expandafter\grph_rotate_box
+   \fi{#1}}
+
+\def\grph_rotate_box#1% {angle} \hbox/\vbox/\vtop
+  {\bgroup
+   \hbox\bgroup % compatibility hack
+     \edef\p_rotation_rotation{#1}%
+     \dowithnextboxcs\grph_rotate_finish_box}
+
+\def\grph_rotate_finish_box
+  {\setfalse\c_grph_rotate_not_fit      % this is the same as broad but
+   \setfalse\c_grph_rotate_center       % without the following grab as
+   \setfalse\c_grph_rotate_obey_depth   % we call finish directly
+   \grph_rotate_finish_indeed
+   \egroup
+   \egroup}
+
+\def\grph_rotate_finish_indeed
+  {\hbox\bgroup
+     \ifx\p_rotation_rotation\empty
+       \grph_rotate_finish_nop
+     \else
+       \grph_rotate_finish_yes
+     \fi
+   \egroup}
+
+\def\grph_rotate_finish_nop
+  {\boxcursor\box\nextbox}
+
+\setvalue{\??rotatepreset\v!left}%
+  {\edef\p_rotation_rotation{\doifelseoddpage{90}{270}}}
+
+\setvalue{\??rotatepreset\v!right}%
+  {\edef\p_rotation_rotation{\doifelseoddpage{270}{90}}}
+
+\setvalue{\??rotatepreset\v!inner}%
+  {\signalrightpage
+   \doifelserightpage{\def\p_rotation_rotation{270}}{\def\p_rotation_rotation{90}}}
+
+\setvalue{\??rotatepreset\v!outer}%
+  {\signalrightpage
+   \doifelserightpage{\def\p_rotation_rotation{90}}{\def\p_rotation_rotation{270}}}
+
+\setvalue{\??rotatepreset\v!default}%
+  {\edef\p_rotation_rotation{\realnumber{\p_rotation_rotation}}}% get rid of leading zeros and spaces
+
+\def\grph_rotate_finish_yes
+  {\csname\??rotatepreset
+     \ifcsname\??rotatepreset\p_rotation_rotation\endcsname\p_rotation_rotation\else\v!default\fi
+   \endcsname
+   \setbox\nextbox\vpack{\box\nextbox}% not really needed
+   \dontcomplain
+   \ifconditional\c_grph_rotate_center
+     \d_grph_rotate_saved_width \wd\nextbox
+     \d_grph_rotate_saved_height\ht\nextbox
+     \d_grph_rotate_saved_depth \dp\nextbox
+     \setbox\nextbox\vpack{\vskip.5\ht\nextbox\hskip-.5\wd\nextbox\box\nextbox}%
+     \smashbox\nextbox
+   \fi
+   \d_grph_rotate_width \wd\nextbox
+   \d_grph_rotate_height\ht\nextbox
+   \d_grph_rotate_depth \dp\nextbox
+   \setbox\nextbox\vpack{\hpack{\raise\dp\nextbox\box\nextbox}}%
+   \d_grph_rotate_used_height \ht\nextbox
+   % much of the next happens in lua (all the sin and cos) so we can do that in
+   % one go if needed
+   \setcalculatedcos\cos\p_rotation_rotation
+   \setcalculatedsin\sin\p_rotation_rotation
+   \ifdim\sin\points>\zeropoint
+     \ifdim\cos\points>\zeropoint
+       \grph_rotate_calculate_a
+       \grph_rotate_apply
+     \else
+       \grph_rotate_calculate_b
+       \grph_rotate_apply
+       \wd\nextbox\ifconditional\c_grph_rotate_not_fit\sin\d_grph_rotate_depth\else\d_grph_rotate_x_size\fi
+     \fi
+   \else
+     \ifdim\cos\points<\zeropoint
+       \grph_rotate_calculate_c
+       \grph_rotate_apply
+       \wd\nextbox\ifconditional\c_grph_rotate_not_fit\negated\sin\d_grph_rotate_height\else\d_grph_rotate_x_size\fi
+     \else\ifdim\sin\points=\zeropoint
+       \grph_rotate_calculate_d
+       \grph_rotate_apply
+       % no wd ?
+     \else
+       \grph_rotate_calculate_e
+       \grph_rotate_apply
+       \wd\nextbox\ifconditional\c_grph_rotate_not_fit\negated\sin\d_grph_rotate_height\else\d_grph_rotate_x_size\fi
+     \fi\fi
+   \fi
+   \ifconditional\c_grph_rotate_center
+     \setbox\nextbox\vpack{\vskip-.5\d_grph_rotate_saved_height\hskip.5\d_grph_rotate_saved_height\box\nextbox}%
+     \wd\nextbox\d_grph_rotate_saved_width
+     \ht\nextbox\d_grph_rotate_saved_height
+     \dp\nextbox\d_grph_rotate_saved_depth
+   \fi
+   \boxcursor\box\nextbox}
+
+\def\grph_rotate_calculate_a
+  {\d_grph_rotate_x_size\dimexpr\cos\d_grph_rotate_width+\sin\d_grph_rotate_used_height\relax
+   \d_grph_rotate_y_size\dimexpr\sin\d_grph_rotate_width+\cos\d_grph_rotate_used_height\relax
+   \d_grph_rotate_x_position\zeropoint
+   \d_grph_rotate_y_position\cos\d_grph_rotate_used_height
+   \ifconditional\c_grph_rotate_not_fit
+     \d_grph_rotate_x_offset\dimexpr\negated\sin\d_grph_rotate_used_height+\sin\d_grph_rotate_depth\relax
+   \fi
+   \ifconditional\c_grph_rotate_obey_depth
+     \d_grph_rotate_y_offset\cos\d_grph_rotate_depth
+   \fi}
+
+\def\grph_rotate_calculate_b
+  {\d_grph_rotate_x_size\dimexpr\negated\cos\d_grph_rotate_width+\sin\d_grph_rotate_used_height\relax
+   \d_grph_rotate_y_size\dimexpr\sin\d_grph_rotate_width+\negated\cos\d_grph_rotate_used_height\relax
+   \d_grph_rotate_x_position\negated\cos\d_grph_rotate_width
+   \d_grph_rotate_y_position\zeropoint
+   \ifconditional\c_grph_rotate_not_fit
+     \d_grph_rotate_x_offset\dimexpr-\d_grph_rotate_x_size+\sin\d_grph_rotate_depth\relax
+   \fi
+   \ifconditional\c_grph_rotate_obey_depth
+     \d_grph_rotate_y_offset\negated\cos\d_grph_rotate_height
+   \fi}
+
+\def\grph_rotate_calculate_c
+  {\d_grph_rotate_x_size\dimexpr\negated\cos\d_grph_rotate_width+\negated\sin\d_grph_rotate_used_height\relax
+   \d_grph_rotate_y_size\dimexpr\negated\sin\d_grph_rotate_width+\negated\cos\d_grph_rotate_used_height\relax
+   \d_grph_rotate_x_position\d_grph_rotate_x_size
+   \d_grph_rotate_y_position\negated\sin\d_grph_rotate_width
+   \ifconditional\c_grph_rotate_not_fit
+     \d_grph_rotate_x_offset\dimexpr-\d_grph_rotate_x_size+\negated\sin\d_grph_rotate_height\relax
+   \fi
+   \ifconditional\c_grph_rotate_obey_depth
+     \d_grph_rotate_y_offset\dimexpr\d_grph_rotate_y_size+\cos\d_grph_rotate_depth\relax
+   \fi}
+
+\def\grph_rotate_calculate_d
+  {\d_grph_rotate_x_size\dimexpr\cos\d_grph_rotate_width+\negated\sin\d_grph_rotate_used_height\relax
+   \d_grph_rotate_y_size\dimexpr\negated\sin\d_grph_rotate_width+\cos\d_grph_rotate_used_height\relax
+   \d_grph_rotate_x_position\zeropoint
+   \d_grph_rotate_y_position\d_grph_rotate_y_size
+   \d_grph_rotate_x_offset\zeropoint
+   \ifconditional\c_grph_rotate_obey_depth
+     \d_grph_rotate_y_offset\d_grph_rotate_depth
+   \fi}
+
+\def\grph_rotate_calculate_e
+  {\d_grph_rotate_x_size\dimexpr\cos\d_grph_rotate_width+\negated\sin\d_grph_rotate_used_height\relax
+   \d_grph_rotate_y_size\dimexpr\negated\sin\d_grph_rotate_width+\cos\d_grph_rotate_used_height\relax
+   \d_grph_rotate_x_position\negated\sin\d_grph_rotate_used_height
+   \d_grph_rotate_y_position\d_grph_rotate_y_size
+   \ifconditional\c_grph_rotate_not_fit
+     \d_grph_rotate_x_offset\dimexpr-\d_grph_rotate_x_size+\negated\sin\d_grph_rotate_height\relax
+   \fi
+   \ifconditional\c_grph_rotate_obey_depth
+     \d_grph_rotate_y_offset\negated\sin\d_grph_rotate_depth
+   \fi}
+
+\def\grph_rotate_apply
+  {\setbox\nextbox\vpack to \d_grph_rotate_y_size
+     {\vfill
+      \hpack to \d_grph_rotate_x_size
+        {\dostartrotation\p_rotation_rotation
+           \wd\nextbox\zeropoint
+           \ht\nextbox\zeropoint
+           \box\nextbox
+         \dostoprotation
+         \hfill}%
+      \kern\d_grph_rotate_y_position}%
+   \setbox\nextbox\hpack
+     {\kern\dimexpr\d_grph_rotate_x_position+\d_grph_rotate_x_offset\relax
+      \lower\d_grph_rotate_y_offset\box\nextbox}}
+
+% \dostepwiserecurse{0}{360}{10}
+%   {\startlinecorrection[blank]
+%    \hbox
+%      {\expanded{\setuprotate[rotation=\recurselevel]}%
+%       \traceboxplacementtrue
+%       \hbox to .2\hsize{\hss\ruledhbox{\rotate[location=depth] {\ruledhbox{\bfb  (depth)}}}}%
+%       \hbox to .2\hsize{\hss\ruledhbox{\rotate[location=fit]   {\ruledhbox{\bfb    (fit)}}}}%
+%       \hbox to .2\hsize{\hss\ruledhbox{\rotate[location=broad] {\ruledhbox{\bfb  (broad)}}}}%
+%       \hbox to .2\hsize{\hss\ruledhbox{\rotate[location=normal]{\ruledhbox{\bfb (normal)}}}}%
+%       \hbox to .2\hsize{\hss\ruledhbox{\rotate[location=high]  {\ruledhbox{\bfb   (high)}}}}}
+%    \stoplinecorrection}
+
+\protect \endinput