gnu/dist/groff/src/preproc/eqn/script.cpp

   1 /*      $NetBSD$        */
   2
   3 // -*- C++ -*-
   4 /* Copyright (C) 1989, 1990, 1991, 1992, 2002, 2004
   5    Free Software Foundation, Inc.
   6      Written by James Clark (jjc@jclark.com)
   7
   8 This file is part of groff.
   9
  10 groff is free software; you can redistribute it and/or modify it under
  11 the terms of the GNU General Public License as published by the Free
  12 Software Foundation; either version 2, or (at your option) any later
  13 version.
  14
  15 groff is distributed in the hope that it will be useful, but WITHOUT ANY
  16 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  17 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  18 for more details.
  19
  20 You should have received a copy of the GNU General Public License along
  21 with groff; see the file COPYING.  If not, write to the Free Software
  22 Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA. */
  23
  24 #include "eqn.h"
  25 #include "pbox.h"
  26
  27 class script_box : public pointer_box {
  28 private:
  29   box *sub;
  30   box *sup;
  31 public:
  32   script_box(box *, box *, box *);
  33   ~script_box();
  34   int compute_metrics(int);
  35   void output();
  36   void debug_print();
  37   int left_is_italic();
  38   void hint(unsigned);
  39   void check_tabs(int);
  40 };
  41
  42 /* The idea is that the script should attach to the rightmost box
  43 of a list. For example, given `2x sup 3', the superscript should
  44 attach to `x' rather than `2x'. */
  45
  46 box *make_script_box(box *nuc, box *sub, box *sup)
  47 {
  48   list_box *b = nuc->to_list_box();
  49   if (b != 0) {
  50     b->list.p[b->list.len-1] = make_script_box(b->list.p[b->list.len - 1],
  51                                                sub,
  52                                                sup);
  53     return b;
  54   }
  55   else
  56     return new script_box(nuc, sub, sup);
  57 }
  58
  59 script_box::script_box(box *pp, box *qq, box *rr)
  60 : pointer_box(pp), sub(qq), sup(rr)
  61 {
  62 }
  63
  64 script_box::~script_box()
  65 {
  66   delete sub;
  67   delete sup;
  68 }
  69
  70 int script_box::left_is_italic()
  71 {
  72   return p->left_is_italic();
  73 }
  74
  75 int script_box::compute_metrics(int style)
  76 {
  77   int res = p->compute_metrics(style);
  78   p->compute_subscript_kern();
  79   printf(".nr " SIZE_FORMAT " \\n[.ps]\n", uid);
  80   if (!(style <= SCRIPT_STYLE && one_size_reduction_flag))
  81     set_script_size();
  82   printf(".nr " SMALL_SIZE_FORMAT " \\n[.ps]\n", uid);
  83   if (sub != 0)
  84     sub->compute_metrics(cramped_style(script_style(style)));
  85   if (sup != 0)
  86     sup->compute_metrics(script_style(style));
  87   // 18a
  88   if (p->is_char()) {
  89     printf(".nr " SUP_RAISE_FORMAT " 0\n", uid);
  90     printf(".nr " SUB_LOWER_FORMAT " 0\n", uid);
  91   }
  92   else {
  93     printf(".nr " SUP_RAISE_FORMAT " \\n[" HEIGHT_FORMAT "]-%dM>?0\n",
  94            uid, p->uid, sup_drop);
  95     printf(".nr " SUB_LOWER_FORMAT " \\n[" DEPTH_FORMAT "]+%dM\n",
  96            uid, p->uid, sub_drop);
  97   }
  98   printf(".ps \\n[" SIZE_FORMAT "]u\n", uid);
  99   if (sup == 0) {
 100     assert(sub != 0);
 101     // 18b
 102     printf(".nr " SUB_LOWER_FORMAT " \\n[" SUB_LOWER_FORMAT "]>?%dM>?(\\n["
 103            HEIGHT_FORMAT "]-(%dM*4/5))\n",
 104            uid, uid, sub1, sub->uid, x_height);
 105   }
 106   else {
 107     // sup != 0
 108     // 18c
 109     int pos;
 110     if (style == DISPLAY_STYLE)
 111       pos = sup1;
 112     else if (style & 1)         // not cramped
 113       pos = sup2;
 114     else
 115       pos = sup3;
 116     printf(".nr " SUP_RAISE_FORMAT " \\n[" SUP_RAISE_FORMAT
 117            "]>?%dM>?(\\n[" DEPTH_FORMAT "]+(%dM/4))\n",
 118            uid, uid, pos, sup->uid, x_height);
 119     // 18d
 120     if (sub != 0) {
 121       printf(".nr " SUB_LOWER_FORMAT " \\n[" SUB_LOWER_FORMAT "]>?%dM\n",
 122              uid, uid, sub2);
 123       // 18e
 124       printf(".nr " TEMP_REG " \\n[" DEPTH_FORMAT "]-\\n["
 125              SUP_RAISE_FORMAT "]+\\n[" HEIGHT_FORMAT "]-\\n["
 126              SUB_LOWER_FORMAT "]+(4*%dM)\n",
 127              sup->uid, uid, sub->uid, uid, default_rule_thickness);
 128       printf(".if \\n[" TEMP_REG "] \\{");
 129       printf(".nr " SUB_LOWER_FORMAT " +\\n[" TEMP_REG "]\n", uid);
 130       printf(".nr " TEMP_REG " (%dM*4/5)-\\n[" SUP_RAISE_FORMAT
 131              "]+\\n[" DEPTH_FORMAT "]>?0\n",
 132              x_height, uid, sup->uid);
 133       printf(".nr " SUP_RAISE_FORMAT " +\\n[" TEMP_REG "]\n", uid);
 134       printf(".nr " SUB_LOWER_FORMAT " -\\n[" TEMP_REG "]\n", uid);
 135       printf(".\\}\n");
 136     }
 137   }
 138   printf(".nr " WIDTH_FORMAT " 0\\n[" WIDTH_FORMAT "]", uid, p->uid);
 139   if (sub != 0 && sup != 0)
 140     printf("+((\\n[" WIDTH_FORMAT "]-\\n[" SUB_KERN_FORMAT "]>?\\n["
 141            WIDTH_FORMAT "])+%dM)>?0\n",
 142            sub->uid, p->uid, sup->uid, script_space);
 143   else if (sub != 0)
 144     printf("+(\\n[" WIDTH_FORMAT "]-\\n[" SUB_KERN_FORMAT "]+%dM)>?0\n",
 145            sub->uid, p->uid, script_space);
 146   else if (sup != 0)
 147     printf("+(\\n[" WIDTH_FORMAT "]+%dM)>?0\n", sup->uid, script_space);
 148   else
 149     printf("\n");
 150   printf(".nr " HEIGHT_FORMAT " \\n[" HEIGHT_FORMAT "]",
 151          uid, p->uid);
 152   if (sup != 0)
 153     printf(">?(\\n[" SUP_RAISE_FORMAT "]+\\n[" HEIGHT_FORMAT "])",
 154            uid, sup->uid);
 155   if (sub != 0)
 156     printf(">?(-\\n[" SUB_LOWER_FORMAT "]+\\n[" HEIGHT_FORMAT "])",
 157            uid, sub->uid);
 158   printf("\n");
 159   printf(".nr " DEPTH_FORMAT " \\n[" DEPTH_FORMAT "]",
 160          uid, p->uid);
 161   if (sub != 0)
 162     printf(">?(\\n[" SUB_LOWER_FORMAT "]+\\n[" DEPTH_FORMAT "])",
 163            uid, sub->uid);
 164   if (sup != 0)
 165     printf(">?(-\\n[" SUP_RAISE_FORMAT "]+\\n[" DEPTH_FORMAT "])",
 166            uid, sup->uid);
 167   printf("\n");
 168   return res;
 169 }
 170
 171 void script_box::output()
 172 {
 173   p->output();
 174   if (sup != 0) {
 175     printf("\\Z" DELIMITER_CHAR);
 176     printf("\\v'-\\n[" SUP_RAISE_FORMAT "]u'", uid);
 177     printf("\\s[\\n[" SMALL_SIZE_FORMAT "]u]", uid);
 178     sup->output();
 179     printf("\\s[\\n[" SIZE_FORMAT "]u]", uid);
 180     printf(DELIMITER_CHAR);
 181   }
 182   if (sub != 0) {
 183     printf("\\Z" DELIMITER_CHAR);
 184     printf("\\v'\\n[" SUB_LOWER_FORMAT "]u'", uid);
 185     printf("\\s[\\n[" SMALL_SIZE_FORMAT "]u]", uid);
 186     printf("\\h'-\\n[" SUB_KERN_FORMAT "]u'", p->uid);
 187     sub->output();
 188     printf("\\s[\\n[" SIZE_FORMAT "]u]", uid);
 189     printf(DELIMITER_CHAR);
 190   }
 191   printf("\\h'\\n[" WIDTH_FORMAT "]u-\\n[" WIDTH_FORMAT "]u'",
 192          uid, p->uid);
 193 }
 194
 195 void script_box::hint(unsigned flags)
 196 {
 197   p->hint(flags & ~HINT_NEXT_IS_ITALIC);
 198 }
 199
 200 void script_box::debug_print()
 201 {
 202   fprintf(stderr, "{ ");
 203   p->debug_print();
 204   fprintf(stderr, " }");
 205   if (sub) {
 206     fprintf(stderr, " sub { ");
 207     sub->debug_print();
 208     fprintf(stderr, " }");
 209   }
 210   if (sup) {
 211     fprintf(stderr, " sup { ");
 212     sup->debug_print();
 213     fprintf(stderr, " }");
 214   }
 215 }
 216
 217 void script_box::check_tabs(int level)
 218 {
 219   if (sup)
 220     sup->check_tabs(level + 1);
 221   if (sub)
 222     sub->check_tabs(level + 1);
 223   p->check_tabs(level);
 224 }