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1%D \module
2%D   [       file=pack-lyr,
3%D        version=2000.10.20,
4%D          title=\CONTEXT\ Packaging Macros,
5%D       subtitle=Layers,
6%D         author=Hans Hagen,
7%D           date=\currentdate,
8%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
9%C
10%C This module is part of the \CONTEXT\ macro||package and is
11%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
12%C details.
13
14\writestatus
{
loading
}{
ConTeXt
 Packaging
 Macros
 /
 Layers
}
15
16% todo : first / last / next / +... => page key
17%        test on left/right box when no doublesided option given
18%        use \ifcsname instead of doifvalue
19
20\unprotect
21
22% When being backgrounds layers get the background offset displacement. Should be
23% an option, on by default (compatibility).
24
25%D The layering mechanism implemented here is independent of the output routine, but
26%D future extensions may depend on a more close cooperation.
27%D
28%D First we overload a macro from \type {pack-rul}. From now on we accept a
29%D (optional) argument: the specific layer it will go in. This means that we can
30%D move an overlay from one background to the other using the dimensions of the
31%D parent.
32
33\ifdefined
\defineoverlay
 \else
 \message
{
loaded
 to
 early
}
 \wait
 \fi
34
35\unexpanded
\def
\defineoverlay
36  {
\dotripleempty
\pack_framed_define_overlay
}
37
38\def
\pack_framed_define_overlay
[#
1
][#
2
][#
3
]
% overlay [layer] content
39  {
\ifthirdargument
40    %\writestatus{BEWARE}{This (overlay definition) has changed!}% temp
41     \def
\pack_framed_define_overlay_indeed
##
1
{
\setvalue
{
\??overlay
##
1
}{
\setlayer
[#
2
]
{
\executedefinedoverlay
{
##
1
}{
#
3
}}}}
%
42   \else
43     \def
\pack_framed_define_overlay_indeed
##
1
{
\setvalue
{
\??overlay
##
1
}{
\executedefinedoverlay
{
##
1
}{
#
2
}}}
%
44   \fi
45   \processcommalist
[#
1
]
\pack_framed_define_overlay_indeed
}
46
47%D We use the command handler code. The previous, more direct parameter handling was
48%D 25\% faster when no parameters were passed when adding content to a layer.
49%D However, when we pass for instance a preset, the new methos is some 10\% faster
50%D and it happens that in most cases we do pass some parameters. It would be
51%D interesting to see if we can push the preset in between the regular chain but it
52%D could also lead to unwanted side effects when nesting layer placement.
53
54\installcorenamespace
{
layer
}
55\installcorenamespace
{
layerbox
}
56\installcorenamespace
{
layerpreset
}
57\installcorenamespace
{
layerposition
}
 % brr, unreadable
58
59%D \macros
60%D   {definelayer,setuplayer}
61%D
62%D Each layer gets its own (global) box. This also means that the data that goes
63%D into a layer, is typeset immediately. Each layer automatically gets an associated
64%D overlay, which can be used in any background assignment.
65%D
66%D After a layer is defined, you can change its characteristics.
67
68\installcommandhandler
 \??layer
 {
layer
}
 \??layer
69
70\setuplayer
71  [
\c!state
=
\v!start
,
72  %\c!doublesided=,
73  %\c!preset=,
74  %\c!option=,
75  %\c!corner=,
76  %\c!page=,
77  %\c!rotation=, % geen 0 !
78   \c!direction
=
\v!normal
,
79   \c!position
=
\v!no
,
80   \c!method
=
\v!overlay
,
81   \c!x
=
\zeropoint
,
82   \c!y
=
\zeropoint
,
83   \c!line
=
0
,
84   \c!column
=
0
,
85   \c!width
=
\wd
\nextbox
,
  % don't change this globally
86   \c!height
=
\ht
\nextbox
,
 % don't change this globally
87   \c!offset
=
\zeropoint
,
88   \c!hoffset
=
\zeropoint
,
89   \c!voffset
=
\zeropoint
,
90   \c!dx
=
\zeropoint
,
91   \c!dy
=
\zeropoint
,
92   \c!location
=
rb
,
93   \c!sx
=
1
,
94   \c!sy
=
1
,
95   \c!region
=
\layeranchor
]
96
97\def
\layeranchor
{
\currentlayer
:
\the
\realpageno
}
98
99\let
\p_pack_layers_doublesided
\empty
100\let
\p_pack_layers_state
      \empty
101\let
\p_pack_layers_option
     \empty
102\let
\p_pack_layers_method
     \empty
103\let
\p_pack_layers_preset
     \empty
104\let
\p_pack_layers_rotation
   \empty
105\let
\p_pack_layers_position
   \empty
106\let
\p_pack_layers_hoffset
    \empty
107\let
\p_pack_layers_voffset
    \empty
108\let
\p_pack_layers_offset
     \empty
109\let
\p_pack_layers_dx
         \empty
110\let
\p_pack_layers_dy
         \empty
111\let
\p_pack_layers_sx
         \empty
112\let
\p_pack_layers_sy
         \empty
113\let
\p_pack_layers_x
          \empty
114\let
\p_pack_layers_y
          \empty
115\let
\p_pack_layers_corner
     \empty
116\let
\p_pack_layers_location
   \empty
117\let
\p_pack_layers_line
       \empty
118\let
\p_pack_layers_column
     \empty
119\let
\p_pack_layers_width
      \empty
120\let
\p_pack_layers_height
     \empty
121\let
\p_pack_layers_direction
  \empty
122\let
\p_pack_layers_region
     \empty
123
124\let
\m_pack_layers_page
       \empty
125\let
\m_pack_layers_target
     \empty
126\let
\m_pack_layers_region
     \empty
127\let
\m_pack_layers_anchor
     \empty
128
129\newconditional
\c_pack_layers_repeated
130\newconditional
\c_pack_layers_trace
131\newcount
      \c_pack_layers_current_data
132
133\newbox
\b_layers
134
135\newdimen
\d_pack_layers_x_size
136\newdimen
\d_pack_layers_y_size
137\newdimen
\d_pack_layers_x_offset
138\newdimen
\d_pack_layers_y_offset
139\newdimen
\d_pack_layers_x_position
140\newdimen
\d_pack_layers_y_position
141
142\newdimen
\layerwidth
143\newdimen
\layerheight
144
145\let
\lastlayerxpos
\!!zeropoint
146\let
\lastlayerypos
\!!zeropoint
147\let
\lastlayerwd
  \!!zeropoint
148\let
\lastlayerht
  \!!zeropoint
149\let
\lastlayerdp
  \!!zeropoint
150
151\appendtoks
152    \edef
\p_pack_layers_doublesided
{
\layerparameter
\c!doublesided
}
%
153    \ifx
\p_pack_layers_doublesided
\v!yes
154        \relateparameterhandlers
{
layer
}{
\v!left
 \currentlayer
}{
layer
}
\currentlayer
 % permits left*
155        \relateparameterhandlers
{
layer
}{
\v!right
\currentlayer
}{
layer
}
\currentlayer
 % permits right*
156        \pack_layers_preset_box
{
\v!left
 \currentlayer
}
%
157        \pack_layers_preset_box
{
\v!right
\currentlayer
}
%
158    \fi
159    \pack_layers_preset_box
\currentlayer
160    \normalexpanded
{
\defineoverlay
[
\currentlayer
][
\noexpand
\composedlayer
{
\currentlayer
}
]
}
%
161\to
 \everydefinelayer
162
163\def
\pack_layers_preset_box
#
1
%
164  {
\ifcsname
\??layerbox
#
1
\endcsname
165     \resetlayer
[#
1
]
%
166   \else
167     \expandafter
\newbox
\csname
\??layerbox
#
1
\endcsname
168   \fi
}
169
170%D \macros
171%D  {resetlayer}
172%D
173%D This macro hardly needs an explanation (but is seldom needed anyway).
174
175\def
\pack_layers_reset_box
#
1
%
176  {
\ifcsname
\??layerbox
#
1
\endcsname
177    %\global\setbox\csname\??layerbox#1\endcsname\emptybox
178     \global\setbox\lastnamedcs
\emptybox
179   \fi
}
180
181\def
\resetlayer
[#
1
]
%
182  {
\pack_layers_reset_box
{
#
1
}
%
183   \pack_layers_reset_box
{
\v!left
 #
1
}
%
184   \pack_layers_reset_box
{
\v!right
#
1
}
%
185   \pack_layers_reset_box
{
#
1
:
\the
\realpageno
}}
186
187%D \macros
188%D   {setlayer}
189%D
190%D Data is moved into a layer with the following macro. When \type {position} is
191%D set, relative positioning is used, with the current point as reference point.
192%D Otherwise the topleft corner is used as reference point.
193%D
194%D \starttyping
195%D \setlayer [identifier] [optional parameters] {data}
196%D \stoptyping
197
198\def
\setcurrentlayerdimensions
199  {
\dodoubleempty
\pack_layers_set_current_dimensions
}
200
201\def
\pack_layers_set_current_dimensions
[#
1
][#
2
]
% name left|right
202  {
\edef
\currentlayerwidth
 {
\thelayerwidth
 {
#
2
#
1
}}
%
203   \edef
\currentlayerheight
{
\thelayerheight
{
#
2
#
1
}}}
204
205\def
\thelayerwidth
 #
1
{
\the\ifcsname
\??layerbox
#
1
\endcsname\wd\lastnamedcs\else
\zeropoint
\fi
}
206\def
\thelayerheight
#
1
{
\the\ifcsname
\??layerbox
#
1
\endcsname\ht\lastnamedcs\else
\zeropoint
\fi
}
207
208\unexpanded
\def
\setlayer
209  {
\dotripleempty
\pack_layers_set
}
210
211\def
\pack_layers_set
[#
1
][#
2
][#
3
]
% #4 == box do \fi is ok
212  {
\bgroup
213   \checkpositionoverlays
 % otherwise funny regions
214   \edef
\currentlayer
{
#
1
}
%
215   \edef
\p_pack_layers_state
{
\layerparameter
\c!state
}
%
216   \ifx
\p_pack_layers_state
\v!stop
217     \dowithnextboxcs
\egroup
\hbox
 % no pack ?
218   \orelse
\ifthirdargument
219     \pack_layers_set_indeed
[#
1
][#
2
][#
3
]
%
220   \else
221      \ifcondition
\validassignment
{
#
2
}
%
222        \pack_layers_set_indeed
[#
1
][][#
2
]
%
223      \else
224        \pack_layers_set_indeed
[#
1
][#
2
][]
%
225      \fi
226   \fi
}
227
228\def
\pack_layers_set_indeed
[#
1
][#
2
][#
3
]
% #2 = links/rechts
229  {
\page_backgrounds_recalculate
 % brrr
230   \global\advance
\c_pack_layers_current_data
\plusone
231   \forgetall
232   \dontcomplain
233   \edef
\p_pack_layers_option
{
\layerparameter
\c!option
}
%
234   \ifx
\p_pack_layers_option
\v!test
235     \settrue
\c_pack_layers_trace
236     \traceboxplacementtrue
237   \fi
238   \edef
\m_pack_layers_target
{
#
2
}
%
239   \dowithnextbox
{
\pack_layers_set_finish
{
#
3
}}
\hbox
}
240
241\def
\pack_layers_set_finish
#
1
%
242  {
\ifcsname
\??layerbox
\currentlayer
\endcsname
 % can move up
243     \ifx
\m_pack_layers_target
\v!even
244       \ifodd
\realpageno
245         % discard nextbox
246       \else
247         \let
\m_pack_layers_target
\v!left
248         \pack_layers_set_content
{
#
1
}
%
249       \fi
250     \orelse\ifx
\m_pack_layers_target
\v!odd
251       \ifodd
\realpageno
252         \let
\m_pack_layers_target
\v!right
253         \pack_layers_set_content
{
#
1
}
%
254       \else
255         % discard nextbox
256       \fi
257     \else
258       \pack_layers_set_content
{
#
1
}
%
259     \fi
260   \else
261     \writestatus
{
layer
}{
unknown
 layer
 \currentlayer
}
%
262   \fi
263   \egroup
}
264
265% todo: left/right
266% todo: get position data in one go
267
268\def
\pack_layers_set_last_position_yes
 % target: left|right
269  {
% this will become one call
270   \edef
\m_pack_layers_anchor
{
\??layerposition
\the
\c_pack_layers_current_data
}
%
271   \edef
\m_pack_layers_page
  {
\MPp
\m_pack_layers_anchor
}
%
272   %edef\m_pack_layers_region{\MPr\m_pack_layers_anchor}% wrong one
273   \edef
\m_pack_layers_region
{
\layerparameter
\c!region
}
%
274   \d_pack_layers_x_position
 \dimexpr
-
\MPx
\m_pack_layers_region
+
\MPx
\m_pack_layers_anchor
\relax
275   \d_pack_layers_y_position
 \dimexpr
 \MPy
\m_pack_layers_region
-
\MPy
\m_pack_layers_anchor
+
\MPh
\m_pack_layers_region
\relax
276   \xdef
\lastlayerxpos
{
\the
\d_pack_layers_x_position
}
%
277   \xdef
\lastlayerypos
{
\the
\d_pack_layers_y_position
}
%
278 % \writestatus{layering}{region: \m_pack_layers_region=>\MPxywhd\m_pack_layers_region}%
279 % \writestatus        {}{anchor: \m_pack_layers_anchor=>\MPxywhd\m_pack_layers_anchor}%
280 % \writestatus        {}{offset: \c!dx,\c!dy          =>\lastlayerxpos,\lastlayerypos}%
281   \global
\letlayerparameter
\c!state\v!start
 % needed ?
282   \setbox
\b_layers
\vpack
 to
 \d_pack_layers_y_size
283     {
\hpack
 to
 \d_pack_layers_x_size
284        {
\xypos
\m_pack_layers_anchor
\hss
}
%
285      \vss
}}
286
287\def
\pack_layers_set_last_position_nop
288  {
\setbox
\b_layers
\emptybox
289   \d_pack_layers_x_position
\p_pack_layers_sx
\dimexpr
\p_pack_layers_x
\relax
290   \d_pack_layers_y_position
\p_pack_layers_sy
\dimexpr
\p_pack_layers_y
\relax
291   \glet
\lastlayerxpos
\!!zeropoint
292   \glet
\lastlayerypos
\!!zeropoint
293   \doifinset
\v!bottom
\p_pack_layers_corner
\pack_layers_set_bottom_positions
294   \doifinset
\v!right
 \p_pack_layers_corner
\pack_layers_set_right_positions
295   \doifinset
\v!middle
\p_pack_layers_corner
\pack_layers_set_middle_positions
296   \edef
\m_pack_layers_page
{
\layerparameter
\c!page
}}
297
298\unexpanded
\def
\definelayerpreset
299  {
\dodoubleargument
\pack_layers_define_preset
}
300
301\def
\pack_layers_define_preset
[#
1
][#
2
]
%
302  {
\doifelseassignment
{
#
2
}
303     {
\setvalue
{
\??layerpreset
#
1
}{
\setupcurrentlayer
[#
2
]
}}
304     {
\setvalue
{
\??layerpreset
#
1
}{
\csname
\??layerpreset
#
2
\endcsname
}}}
305
306\def
\pack_layers_set_content
#
1
%
307  {
\layerwidth
 \layerparameter
\c!width
  % global (local later)
308   \layerheight
\layerparameter
\c!height
 % global (local later)
309   \d_pack_layers_x_size
\layerwidth
310   \d_pack_layers_y_size
\layerheight
311   %
312   \setupcurrentlayer
[#
1
]
% preroll
313   %
314   \edef
\p_pack_layers_preset
   {
\layerparameter
\c!preset
  }
%
315   %
316   \ifcsname
\??layerpreset
\p_pack_layers_preset
\endcsname
317     \lastnamedcs
318     \setupcurrentlayer
[#
1
]
% postroll
319   \fi
320   %
321   \edef
\p_pack_layers_rotation
 {
\layerparameter
\c!rotation
 }
%
322   \edef
\p_pack_layers_position
 {
\layerparameter
\c!position
 }
%
323   \edef
\p_pack_layers_hoffset
  {
\layerparameter
\c!hoffset
  }
%
324   \edef
\p_pack_layers_voffset
  {
\layerparameter
\c!voffset
  }
%
325   \edef
\p_pack_layers_offset
   {
\layerparameter
\c!offset
   }
%
326   \edef
\p_pack_layers_dx
       {
\layerparameter
\c!dx
       }
%
327   \edef
\p_pack_layers_dy
       {
\layerparameter
\c!dy
       }
%
328   \edef
\p_pack_layers_sx
       {
\layerparameter
\c!sx
       }
%
329   \edef
\p_pack_layers_sy
       {
\layerparameter
\c!sy
       }
%
330   \edef
\p_pack_layers_x
        {
\layerparameter
\c!x
        }
%
331   \edef
\p_pack_layers_y
        {
\layerparameter
\c!y
        }
%
332   \edef
\p_pack_layers_corner
   {
\layerparameter
\c!corner
   }
%
333   \edef
\p_pack_layers_location
 {
\layerparameter
\c!location
 }
%
334   \edef
\p_pack_layers_line
     {
\layerparameter
\c!line
     }
%
335   \edef
\p_pack_layers_column
   {
\layerparameter
\c!column
   }
%
336   \edef
\p_pack_layers_width
    {
\layerparameter
\c!width
    }
% local ones
337   \edef
\p_pack_layers_height
   {
\layerparameter
\c!height
   }
% local ones
338   \edef
\p_pack_layers_direction
{
\layerparameter
\c!direction
}
%
339   %
340   \ifx
\p_pack_layers_position
\v!overlay
341     \let
\p_pack_layers_width
   \zeropoint
342     \let
\p_pack_layers_height
  \zeropoint
343     \let
\p_pack_layers_position
\v!yes
344   \fi
345   \ifempty
\p_pack_layers_rotation
 \else
346     % use direct call
347     \setbox
\nextbox
\hpack
348       {
\rotate
[
\c!location
=
\v!high
,
\c!rotation
=
\layerparameter
\c!rotation
]
{
\box
\nextbox
}}
%
349   \fi
350   \d_pack_layers_x_offset
\p_pack_layers_sx
\dimexpr
351     \ifx
\p_pack_layers_hoffset
\v!max
\d_pack_layers_x_size
\else
\p_pack_layers_hoffset
\fi
+
\p_pack_layers_offset
+
\p_pack_layers_dx
352   \relax
353   \d_pack_layers_y_offset
\p_pack_layers_sy
\dimexpr
354     \ifx
\p_pack_layers_voffset
\v!max
\d_pack_layers_y_size
\else
\p_pack_layers_voffset
\fi
+
\p_pack_layers_offset
+
\p_pack_layers_dy
355   \relax
356   \ifx
\p_pack_layers_position
\v!yes
357     \pack_layers_set_last_position_yes
358   \else
359     \pack_layers_set_last_position_nop
360   \fi
361   %
362   \ifempty
\m_pack_layers_page
 \else
 % is expanded
363     \edef
\m_pack_layers_page
{
:
\m_pack_layers_page
}
%
364     \ifcsname
\??layerbox
\m_pack_layers_target
\currentlayer
\m_pack_layers_page
\endcsname
 \else
365       \expandafter
\newbox
\csname
\??layerbox
\m_pack_layers_target
\currentlayer
\m_pack_layers_page
\endcsname
366     \fi
367   \fi
368   \chardef
\layerpagebox
\csname
\??layerbox
\m_pack_layers_target
\currentlayer
\m_pack_layers_page
\endcsname
369   \ifvoid
\layerpagebox
370     \gsetboxllx
\layerpagebox
\zeropoint
371     \gsetboxlly
\layerpagebox
\zeropoint
372   \fi
373   \global\setbox
\layerpagebox
\vpack
 %to \layerparameter\c!height % new, otherwise no negative y possible
374     {
\offinterlineskip
375      \ifvoid
\layerpagebox
376        \let
\lastlayerwidth
 \zeropoint
377        \let
\lastlayerheight
\zeropoint
378      \else
379        \edef
\lastlayerwidth
 {
\the\wd
\layerpagebox
}
%
380        \edef
\lastlayerheight
{
\the\ht
\layerpagebox
}
%
381        \ht
\layerpagebox
\zeropoint
382        \dp
\layerpagebox
\zeropoint
383        \wd
\layerpagebox
\zeropoint
384        \ifx
\p_pack_layers_direction
\v!reverse
\else
385          \box
\layerpagebox
386        \fi
387      \fi
388      % don't move
389      \xdef
\lastlayerwd
{
\the\wd
\nextbox
}
%
390      \xdef
\lastlayerht
{
\the\ht
\nextbox
}
% % not entirely ok when grid !
391      \xdef
\lastlayerdp
{
\the\dp
\nextbox
}
% % not entirely ok when grid !
392      % this code
393      \ifx
\p_pack_layers_location
\v!grid
394        \ht
\nextbox
\strutheight
395        \dp
\nextbox
\strutdepth
396      \else
397        \setbox
\nextbox
\hpack
398          {
\alignedbox
[
\p_pack_layers_location
]
\vpack
{
\box
\nextbox
}}
%
399      \fi
400      \ifnum
\p_pack_layers_line
=
\zerocount
\else
 % no \ifcase, can be negative
401        \advance
\d_pack_layers_y_position
\dimexpr
\p_pack_layers_line
\lineheight
+
\topskip
-
\lineheight
-
\ht
\nextbox
\relax
402      \fi
403      \ifnum
\p_pack_layers_column
=
\zerocount
\else
 % no \ifcase, can be negative
404        \advance
\d_pack_layers_x_position
\layoutcolumnoffset
\p_pack_layers_column
\relax
405      \fi
406      \ifx
\p_pack_layers_location
\v!grid
407        \setbox
\nextbox
\hpack
408          {
\alignedbox
[
rb
]
\vpack
{
\box
\nextbox
}}
%
409      \fi
410      % ll registration
411      \scratchdimen
\dimexpr
\d_pack_layers_x_position
+
\d_pack_layers_x_offset
\relax
412      \ifdim
\scratchdimen
<
\getboxllx
\layerpagebox
413        \gsetboxllx
\layerpagebox
\scratchdimen
414      \fi
415      \advance
\scratchdimen
\wd
\nextbox
416      \wd
\nextbox
\ifdim
\scratchdimen
>
\lastlayerwidth
 \scratchdimen
 \else
 \lastlayerwidth
 \fi
417      \scratchdimen
\dimexpr
\d_pack_layers_y_position
+
\d_pack_layers_y_offset
\relax
418      \ifdim
\scratchdimen
<
\getboxlly
\layerpagebox
419        \gsetboxlly
\layerpagebox
\scratchdimen
420      \fi
421      % ll compensation
422      \advance
\scratchdimen
\dimexpr\ht
\nextbox
+
\dp
\nextbox
\relax
423      \ht
\nextbox
\ifdim
\scratchdimen
>
\lastlayerheight
 \scratchdimen
 \else
 \lastlayerheight
 \fi
424      \dp
\nextbox
\zeropoint
425      % placement
426      \hsize
\p_pack_layers_width
427      \vpack
 to
 \p_pack_layers_height
 \bgroup
428        \smashbox\nextbox
429        \vskip\dimexpr
\d_pack_layers_y_position
+
\d_pack_layers_y_offset
\relax
430        \hskip\dimexpr
\d_pack_layers_x_position
+
\d_pack_layers_x_offset
\relax
431        % or maybe instead of the \vskip
432        % \raise-\dimexpr\d_pack_layers_y_position+\d_pack_layers_y_offset\relax
433        \box
\nextbox
434        \ifvoid
\layerpagebox
435          % already flushed
436        \else
437          % the reverse case % check !
438          \vskip
-
\dimexpr
\d_pack_layers_y_position
+
\d_pack_layers_y_offset
\relax
439          \box
\layerpagebox
440        \fi
441      \egroup
}
%
442   % when position is true, the layerbox holds the compensation and needs
443   % to be placed; never change this !
444   \ifvoid
\b_layers
 \else
445     \box
\b_layers
446   \fi
}
447
448\def
\pack_layers_set_bottom_positions
449  {
\ifnum
\p_pack_layers_line
=
\zerocount
\else
 % can be < 0
450     \edef
\p_pack_layers_line
{
\the\numexpr
-
\p_pack_layers_line
+
\layoutlines
+
\plusone
\relax
}
% use counter instead ?
451   \fi
452   \ifdim
\d_pack_layers_y_size
>
\zeropoint
453     \advance
\d_pack_layers_y_position
-
\d_pack_layers_y_size
454     \d_pack_layers_y_position
-
\d_pack_layers_y_position
455     \d_pack_layers_y_offset
-
\d_pack_layers_y_offset
456   \fi
}
457
458\def
\pack_layers_set_right_positions
459  {
\ifnum
\p_pack_layers_column
=
\zerocount
\else
 % can be < 0
460     \edef
\p_pack_layers_column
{
\the\numexpr
-
\layerparameter
\c!column
+
\layoutcolumns
+
\plusone
\relax
}
% use counter instead ?
461   \fi
462   \ifdim
\d_pack_layers_x_size
>
\zeropoint
463     \advance
\d_pack_layers_x_position
-
\d_pack_layers_x_size
464     \d_pack_layers_x_position
-
\d_pack_layers_x_position
465     \d_pack_layers_x_offset
-
\d_pack_layers_x_offset
466   \fi
}
467
468\def
\pack_layers_set_middle_positions
469  {
\ifdim
\d_pack_layers_x_size
>
\zeropoint
 \advance
\d_pack_layers_x_position
.
5
\d_pack_layers_x_size
 \fi
470   \ifdim
\d_pack_layers_y_size
>
\zeropoint
 \advance
\d_pack_layers_y_position
.
5
\d_pack_layers_y_size
 \fi
}
471
472%D Given the task to be accomplished, the previous macro is not even that
473%D complicated. It mainly comes down to skipping to the right place and placing a
474%D box on top of or below the existing content. In the case of position tracking,
475%D another reference point is chosen.
476
477%D \macros
478%D  {doifelselayerdata}
479
480\def
\doifelselayerdata
#
1
%
481  {
\ifcsname
\??layerbox
#
1
\endcsname
482    %\ifvoid\csname\??layerbox#1\endcsname
483     \ifvoid
\lastnamedcs
484       \doubleexpandafter\secondoftwoarguments
485     \else
486       \doubleexpandafter\firstoftwoarguments
487     \fi
488   \else
489     \expandafter
\secondoftwoarguments
490   \fi
}
491
492\let
\doiflayerdataelse\doifelselayerdata
493
494%D \macros
495%D  {flushlayer}
496%D
497%D When we flush a layer, we flush both the main one and the page dependent one
498%D (when defined). This feature is more efficient in \ETEX\ since there testing for
499%D an undefined macro does not takes hash space.
500
501% todo: setups before flush, handy hook
502
503\unexpanded
\def
\flushlayer
[#
1
]
% quite core, so optimized (todo: check for void)
504  {
\begingroup
505   \forgetall
506   \edef
\currentlayer
{
#
1
}
%
507   \edef
\p_pack_layers_state
{
\layerparameter
\c!state
}
%
508   \ifx
\p_pack_layers_state
\v!stop
509     % nothing
510   \orelse\ifx
\p_pack_layers_state
\v!next
511     \global
\letlayerparameter
\c!state\v!start
  % dangerous, stack-built-up
512   \orelse\ifx
\p_pack_layers_state
\v!continue
513     \global
\letlayerparameter
\c!state\v!repeat
 % dangerous, stack-built-up
514   \else
515     \edef
\p_pack_layers_doublesided
{
\layerparameter
\c!doublesided
}
%
516     \ifx
\p_pack_layers_doublesided
\v!yes
517       \ifcsname
\??layerbox
#
1
\endcsname
518         % we can make a dedicated one for this
519         \doifbothsidesoverruled
520           {
\pack_layers_flush_double
\v!left
 }
%
521           {
\pack_layers_flush_double
\v!right
}
%
522           {
\pack_layers_flush_double
\v!left
 }
%
523       \else
524         \pack_layers_flush_single
525       \fi
526     \else
527       \pack_layers_flush_single
528     \fi
529   \fi
530   \endgroup
}
531
532% \def\pack_layers_flush_single
533%   {\startoverlay
534%      {\ifcsname\??layerbox  \currentlayer                \endcsname\pack_layers_flush_indeed\plusone   \currentlayer                 \fi}%
535%      {\ifcsname\??layerbox  \currentlayer:\the\realpageno\endcsname\pack_layers_flush_indeed\zerocount{\currentlayer:\the\realpageno}\fi}%
536%    \stopoverlay}
537%
538% \def\pack_layers_flush_double#1%
539%   {\startoverlay
540%      {\ifcsname\??layerbox  \currentlayer                \endcsname\pack_layers_flush_indeed\plusone     \currentlayer                 \fi}%
541%      {\ifcsname\??layerbox  \currentlayer:\the\realpageno\endcsname\pack_layers_flush_indeed\zerocount  {\currentlayer:\the\realpageno}\fi}%
542%      {\ifcsname\??layerbox#1\currentlayer                \endcsname\pack_layers_flush_indeed\plusone  {#1\currentlayer                }\fi}%
543%      {\ifcsname\??layerbox#1\currentlayer:\the\realpageno\endcsname\pack_layers_flush_indeed\zerocount{#1\currentlayer:\the\realpageno}\fi}%
544%    \stopoverlay}
545
546% optimized:
547
548\def
\pack_layers_flush_single
549  {
\ifcsname
\??layerbox
\currentlayer
\endcsname
550     \ifvoid
\lastnamedcs
551       \ifcsname
\??layerbox
\currentlayer
:
\the
\realpageno
\endcsname
552         \ifvoid
\lastnamedcs\else
553           \chardef
\b_layer_two
\lastnamedcs
554           \pack_layers_flush_indeed
\zerocount
{
\currentlayer
:
\the
\realpageno
}
\b_layer_two
555         \fi
556       \fi
557     \else
558       \chardef
\b_layer_one
\lastnamedcs
559       \ifcsname
\??layerbox
\currentlayer
:
\the
\realpageno
\endcsname
560         \ifvoid
\lastnamedcs\else
561           \chardef
\b_layer_two
\lastnamedcs
562           \startoverlay
563             {
\pack_layers_flush_indeed
\plusone
   \currentlayer
                 \b_layer_one
}
%
564             {
\pack_layers_flush_indeed
\zerocount
{
\currentlayer
:
\the
\realpageno
}
\b_layer_two
}
%
565           \stopoverlay
566         \fi
567       \else
568         \pack_layers_flush_indeed
\plusone
\currentlayer
\b_layer_one
569       \fi
570     \fi
571   \orelse\ifcsname
\??layerbox
\currentlayer
:
\the
\realpageno
\endcsname
572     \ifvoid
\lastnamedcs
573        % nothing
574     \else
575       \chardef
\b_layer_two
\lastnamedcs
576       \pack_layers_flush_indeed
\zerocount
{
\currentlayer
:
\the
\realpageno
}
\b_layer_two
577     \fi
578   \fi
}
579
580% less optimized:
581
582\def
\pack_layers_flush_double
#
1
%
583  {
\startoverlay
584     {
\ifcsname
\??layerbox
\currentlayer
\endcsname
585        \ifvoid
\lastnamedcs\else
 \chardef
\b_layer_two
\lastnamedcs
586          \pack_layers_flush_indeed
\plusone
\currentlayer
\b_layer_two
587        \fi
588      \fi
}
%
589     {
\ifcsname
\??layerbox
\currentlayer
:
\the
\realpageno
\endcsname
590        \ifvoid
\lastnamedcs\else
 \chardef
\b_layer_two
\lastnamedcs
591          \pack_layers_flush_indeed
\zerocount
{
\currentlayer
:
\the
\realpageno
}
\b_layer_two
592        \fi
593      \fi
}
%
594     {
\ifcsname
\??layerbox
#
1
\currentlayer
\endcsname
595        \ifvoid
\lastnamedcs\else
 \chardef
\b_layer_two
\lastnamedcs
596          \pack_layers_flush_indeed
\plusone
{
#
1
\currentlayer
}
\b_layer_two
597        \fi
598      \fi
}
%
599     {
\ifcsname
\??layerbox
#
1
\currentlayer
:
\the
\realpageno
\endcsname
600        \ifvoid
\lastnamedcs\else
 \chardef
\b_layer_two
\lastnamedcs
601          \pack_layers_flush_indeed
\zerocount
{
#
1
\currentlayer
:
\the
\realpageno
}
\b_layer_two
602        \fi
603      \fi
}
%
604   \stopoverlay
}
605
606\let
\pack_layers_top_fill
   \relax
607\let
\pack_layers_bottom_fill
\vss
608
609%def\pack_layers_flush_indeed#1#2%
610\def
\pack_layers_flush_indeed
#
1
#
2
#
3
%
611  {
\begingroup
 % already grouped
612   \offinterlineskip
613   \edef
\p_pack_layers_preset
{
\layerparameter
\c!preset
}
%
614   \ifcsname
\??layerpreset
\p_pack_layers_preset
\endcsname
615     \lastnamedcs
616   \fi
617   \edef
\p_pack_layers_method
{
\layerparameter
\c!method
}
%
618   \edef
\p_pack_layers_option
{
\layerparameter
\c!option
}
%
619   \ifx
\p_pack_layers_option
\v!test
620     \settrue
\c_pack_layers_trace
621     \traceboxplacementtrue
622   \fi
623   \ifcase
#
1
\relax
624     \setfalse
\c_pack_layers_repeated
625   \else
626     \edef
\p_pack_layers_position
{
\layerparameter
\c!position
}
%
627     \ifx
\p_pack_layers_position
\v!yes
628       \setfalse
\c_pack_layers_repeated
629     \else
630       \edef
\p_pack_layers_repeat
{
\layerparameter
\c!repeat
}
%
631       \ifx
\p_pack_layers_repeat
\v!yes
632         \settrue
\c_pack_layers_repeated
633       \orelse\ifx
\p_pack_layers_state
\v!repeat
634         \settrue
\c_pack_layers_repeated
635       \else
636         \setfalse
\c_pack_layers_repeated
637       \fi
638     \fi
639   \fi
640   %chardef\b_layers\csname\??layerbox#2\endcsname % trick
641   \let
\b_layers
#
3
%
642   % we need to copy in order to retain the negative offsets for a next
643   % stage of additions, i.e. llx/lly accumulate in repeat mode and the
644   % compensation may differ each flush depending on added content
645   \setbox
\nextbox
646     \ifx
\p_pack_layers_method
\v!fit
647       \pack_layers_positioned_box_yes
648     \else
649       \pack_layers_positioned_box_nop
650     \fi
651   % todo: method=offset => overlayoffset right/down (handy for backgrounds with offset)
652   \doifelseoverlay
{
#
2
}
%
653     {
\setlayoutcomponentattribute
{
\v!layer
:
#
2
}}
%
654     \resetlayoutcomponentattribute
655   % we have conflicting demands: some mechanisms want ll anchoring .. I need to figure this out
656   % and maybe we will have 'origin=bottom' or so
657   \setbox
\nextbox
658   \ifx
\p_pack_layers_option
\v!test
 \ruledvbox
 \else
 \vpack
 \fi
 \ifx
\p_pack_layers_method
\v!overlay
 to
 \d_overlay_height
 \fi
 \layoutcomponentboxattribute
659     {
\pack_layers_top_fill
660%
661%       \hpack \ifx\p_pack_layers_method\v!overlay to \d_overlay_width \fi
662%         {\box\nextbox
663%          \hss}%
664%
665      \ifx
\p_pack_layers_method
\v!overlay
 \wd
\nextbox
\d_overlay_width
\fi
666      \box
\nextbox
667%
668      \pack_layers_bottom_fill
}
%
669   % \edef\currentlayer{#2}% :\the\realpageno}% local .. check \anchor
670   % \edef\p_pack_layers_position{\layerparameter\c!position}% local
671   \ifx
\p_pack_layers_position
\v!yes
672     \edef
\p_pack_layers_region
{
\layerparameter
\c!region
}
%
673     \ifempty
\p_pack_layers_region
\else
674       \anch_mark_tagged_box
\nextbox
\p_pack_layers_region
 % was \layeranchor
675     \fi
676   \fi
677   \box
\nextbox
678   %
679   \ifconditional
\c_pack_layers_repeated
\else
680     \gsetboxllx
\b_layers
\zeropoint
681     \gsetboxlly
\b_layers
\zeropoint
682   \fi
683   \endgroup
}
684
685\def
\pack_layers_positioned_box_yes
686  {
\vpack
687     {
\vskip
-
\getboxlly
\b_layers
688      \hskip
-
\getboxllx
\b_layers
689      \hsize
-
\dimexpr
\getboxllx
\b_layers
-
\wd
\b_layers
\relax
690      \ifconditional
\c_pack_layers_repeated
\copy\else\box\fi
\b_layers
}}
691
692\def
\pack_layers_positioned_box_nop
693  {
\ifconditional
\c_pack_layers_repeated
\copy\else\box\fi
\b_layers
}
694
695% \definelayer[test][method=fit] \setupcolors[state=start,option=test]
696%
697% \framed[framecolor=red,offset=overlay]{\setlayer[test]{aa}\setlayer[test][x=10pt]{g}\flushlayer[test]}
698% \framed[framecolor=red,offset=overlay]{\setlayer[test]{aa}\setlayer[test][x=-10pt]{bb}\flushlayer[test]}
699% \framed[framecolor=red,offset=overlay]{\setlayer[test][x=-20pt]{cccccc}\flushlayer[test]}
700% \framed[framecolor=red,offset=overlay]{\setlayer[test]{dd}\setlayer[test][x=-20pt,y=-3pt]{eeeeee}\flushlayer[test]}
701
702%D \macros
703%D  {composedlayer,placelayer,tightlayer}
704%D
705%D This is a handy shortcut, which saves a couple of braces when we use it as
706%D parameter. This name also suits better to other layering commands.
707
708\unexpanded
\def
\composedlayer
#
1
{
\flushlayer
[#
1
]
}
709
710\unexpanded
\def
\tightlayer
[#
1
]
%
711  {
\hpack
712     {
\def
\currentlayer
{
#
1
}
% todo: left/right
713      \setbox
\nextbox
\emptybox
714      \d_overlay_width
 \layerparameter
\c!width
715      \d_overlay_height
\layerparameter
\c!height
716      \composedlayer
{
#
1
}}}
717
718\let
\placelayer\flushlayer
719
720%D \macros
721%D  {setMPlayer}
722%D
723%D The following layer macro uses the positions that are registered by \METAPOST.
724%D
725%D \starttyping
726%D \definelayer[test]
727%D
728%D \setMPlayer [test] [somepos-1] {Whatever we want here!}
729%D \setMPlayer [test] [somepos-2] {Whatever we need there!}
730%D \setMPlayer [test] [somepos-3] {\externalfigure[cow.mps][width=2cm]}
731%D
732%D \startuseMPgraphic{oeps}
733%D   draw fullcircle scaled 10cm withcolor red ;
734%D   register ("somepos-1",2cm,3cm,center currentpicture) ;
735%D   register ("somepos-2",8cm,5cm,(-1cm,-2cm)) ;
736%D   register ("somepos-3",0cm,0cm,(-2cm,2cm)) ;
737%D \stopuseMPgraphic
738%D
739%D \getMPlayer[test]{\useMPgraphic{oeps}}
740%D \stoptyping
741%D
742%D The last line is equivalent to
743%D
744%D \starttyping
745%D \framed
746%D   [background={foreground,test},offset=overlay]
747%D   {\useMPgraphic{oeps}}
748%D \stoptyping
749
750\unexpanded
\def
\setMPlayer
751  {
\dotripleempty
\pack_layers_set_MP
}
752
753\def
\MPlayerwidth
 {
\hsize
}
754\def
\MPlayerheight
{
\vsize
}
755
756\def
\pack_layers_set_MP
[#
1
][#
2
][#
3
]
%
757  {
\edef
\MPlayerwidth
 {
\MPw
{
#
2
}}
%
758   \edef
\MPlayerheight
{
\MPh
{
#
2
}}
%
759   \setlayer
[#
1
][
\c!x
=
\MPx
{
#
2
}
,
\c!y
=
\MPy
{
#
2
}
,
\c!position
=
\v!no
,
#
3
]
}
760
761\unexpanded
\def
\getMPlayer
762  {
\dodoubleempty
\pack_layers_get_MP
}
763
764\def
\pack_layers_get_MP
[#
1
][#
2
]
%
765  {
\framed
[
\c!background
=
{
\v!foreground
,
#
1
}
,
\c!frame
=
\v!off
,
\c!offset
=
\v!overlay
,
#
2
]
}
 % takes argument
766
767%D Watch out, a redefinition:
768
769\ifdefined
\settextpagecontent
 \else
770    \writestatus
\m!system
{
error
 in
 page
-
lyr
.
tex
}
 \wait
771\fi
772
773\definelayer
774  [
OTRTEXT
]
775
776\setuplayer
777  [
OTRTEXT
]
778  [
\c!width
=
\innermakeupwidth
,
779   \c!height
=
\textheight
]
780
781\let
\normalsettextpagecontent
\settextpagecontent
 % will be overloaded in page-spr
782
783\unexpanded
\def
\settextpagecontent
#
1
#
2
#
3
% #2 and #3 will disappear
784  {
\doifelselayerdata
{
OTRTEXT
}
785     {
\setbox
#
1
\hpack
 to
 \makeupwidth
786        {
\startoverlay
787           {
\tightlayer
[
OTRTEXT
]
}
 % first, otherwise problems with toc
788           {
\normalsettextpagecontent
{
#
1
}{
#
2
}{
#
3
}
\box
#
1
}
789         \stopoverlay
}
%
790      \dp
#
1
\zeropoint
}
%
791     {
\normalsettextpagecontent
{
#
1
}{
#
2
}{
#
3
}}}
792
793\protect
 \endinput
794
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