source/texk/web2c/luatexdir/tex/buildpage.h

   1 /* buildpage.h
   2
   3    Copyright 2009 Taco Hoekwater <taco@luatex.org>
   4
   5    This file is part of LuaTeX.
   6
   7    LuaTeX is free software; you can redistribute it and/or modify it under
   8    the terms of the GNU General Public License as published by the Free
   9    Software Foundation; either version 2 of the License, or (at your
  10    option) any later version.
  11
  12    LuaTeX is distributed in the hope that it will be useful, but WITHOUT
  13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  15    License for more details.
  16
  17    You should have received a copy of the GNU General Public License along
  18    with LuaTeX; if not, see <http://www.gnu.org/licenses/>. */
  19
  20
  21 #ifndef BUILDPAGE_H
  22 #  define BUILDPAGE_H
  23
  24 /* empty = 0 */
  25 #  define inserts_only 1        /* |page_contents| when an insert node has been contributed, but no boxes */
  26 #  define box_there 2           /* |page_contents| when a box or rule has been contributed */
  27
  28 extern halfword page_tail;      /* the final node on the current page */
  29 extern int page_contents;       /* what is on the current page so far? */
  30 extern scaled page_max_depth;   /* maximum box depth on page being built */
  31 extern halfword best_page_break;        /* break here to get the best page known so far */
  32 extern int least_page_cost;     /* the score for this currently best page */
  33 extern scaled best_size;        /* its |page_goal| */
  34
  35 /*
  36 The data structure definitions here use the fact that the |@!height| field
  37 appears in the fourth word of a box node.
  38 @^data structure assumptions@>
  39 */
  40
  41 #  define broken_ptr(A) vlink((A)+2)    /* an insertion for this class will break here if anywhere */
  42 #  define broken_ins(A) vinfo((A)+2)    /* this insertion might break at |broken_ptr| */
  43 #  define last_ins_ptr(A) vlink((A)+3)  /* the most recent insertion for this |subtype| */
  44 #  define best_ins_ptr(A) vinfo((A)+3)  /* the optimum most recent insertion */
  45
  46 extern void initialize_buildpage(void);
  47
  48 #  define page_goal page_so_far[0]      /* desired height of information on page being built */
  49 #  define page_total page_so_far[1]     /* height of the current page */
  50 #  define page_shrink page_so_far[6]    /* shrinkability of the current page */
  51 #  define page_depth page_so_far[7]     /* depth of the current page */
  52
  53 extern scaled page_so_far[8];   /* height and glue of the current page */
  54 extern halfword last_glue;      /* used to implement \.{\\lastskip */
  55 extern int last_penalty;        /* used to implement \.{\\lastpenalty} */
  56 extern scaled last_kern;        /* used to implement \.{\\lastkern} */
  57 extern int last_node_type;      /* used to implement \.{\\lastnodetype} */
  58 extern int insert_penalties;    /* sum of the penalties for held-over insertions */
  59
  60 extern void print_totals(void);
  61 extern void freeze_page_specs(int s);
  62
  63 extern boolean output_active;
  64
  65 extern void start_new_page(void);
  66
  67 #  define contrib_tail nest[0].tail_field
  68                                         /* tail of the contribution list */
  69
  70 extern void build_page(void);   /* append contributions to the current page */
  71 extern void fire_up(halfword c);
  72 extern void resume_after_output(void);
  73
  74 #endif