eqn/script.c

   1 // -*- C++ -*-
   2 /* Copyright (C) 1989, 1990, 1991 Free Software Foundation, Inc.
   3      Written by James Clark (jjc@jclark.uucp)
   4
   5 This file is part of groff.
   6
   7 groff 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 1, or (at your option) any later
  10 version.
  11
  12 groff is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License along
  18 with groff; see the file LICENSE.  If not, write to the Free Software
  19 Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
  20
  21 #include "eqn.h"
  22 #include "pbox.h"
  23
  24 class script_box : public pointer_box {
  25 private:
  26   box *sub;
  27   box *sup;
  28 public:
  29   script_box(box *, box *, box *);
  30   ~script_box();
  31   int compute_metrics(int);
  32   void output();
  33   void debug_print();
  34   int left_is_italic();
  35   void hint(unsigned);
  36   void check_tabs(int);
  37 };
  38
  39 /* The idea is that the script should attach to the rightmost box
  40 of a list. For example, given `2x sup 3', the superscript should
  41 attach to `x' rather than `2x'. */
  42
  43 box *make_script_box(box *nuc, box *sub, box *sup)
  44 {
  45   list_box *b = nuc->to_list_box();
  46   if (b != 0) {
  47     b->list.p[b->list.len-1] = make_script_box(b->list.p[b->list.len - 1],
  48                                                sub,
  49                                                sup);
  50     return b;
  51   }
  52   else
  53     return new script_box(nuc, sub, sup);
  54 }
  55
  56 script_box::script_box(box *pp, box *qq, box *rr)
  57 : pointer_box(pp), sub(qq), sup(rr)
  58 {
  59 }
  60
  61 script_box::~script_box()
  62 {
  63   delete sub;
  64   delete sup;
  65 }
  66
  67 int script_box::left_is_italic()
  68 {
  69   return p->left_is_italic();
  70 }
  71
  72 int script_box::compute_metrics(int style)
  73 {
  74   int res = p->compute_metrics(style);
  75   p->compute_subscript_kern();
  76   printf(".nr " SIZE_FORMAT " \\n[.s]\n", uid);
  77   if (!(style <= SCRIPT_STYLE && one_size_reduction_flag))
  78     set_script_size();
  79   printf(".nr " SMALL_SIZE_FORMAT " \\n[.s]\n", uid);
  80   if (sub != 0)
  81     sub->compute_metrics(cramped_style(script_style(style)));
  82   if (sup != 0)
  83     sup->compute_metrics(script_style(style));
  84   // 18a
  85   if (p->is_char()) {
  86     printf(".nr " SUP_RAISE_FORMAT " 0\n", uid);
  87     printf(".nr " SUB_LOWER_FORMAT " 0\n", uid);
  88   }
  89   else {
  90     printf(".nr " SUP_RAISE_FORMAT " \\n[" HEIGHT_FORMAT "]-%dM>?0\n",
  91            uid, p->uid, sup_drop);
  92     printf(".nr " SUB_LOWER_FORMAT " \\n[" DEPTH_FORMAT "]+%dM\n",
  93            uid, p->uid, sub_drop);
  94   }
  95   printf(".ps \\n[" SIZE_FORMAT "]\n", uid);
  96   if (sup == 0) {
  97     assert(sub != 0);
  98     // 18b
  99     printf(".nr " SUB_LOWER_FORMAT " \\n[" SUB_LOWER_FORMAT "]>?%dM>?(\\n["
 100            HEIGHT_FORMAT "]-(%dM*4/5))\n",
 101            uid, uid, sub1, sub->uid, x_height);
 102   }
 103   else {
 104     // sup != 0
 105     // 18c
 106     int p;
 107     if (style == DISPLAY_STYLE)
 108       p = sup1;
 109     else if (style & 1)         // not cramped
 110       p = sup2;
 111     else
 112       p = sup3;
 113     printf(".nr " SUP_RAISE_FORMAT " \\n[" SUP_RAISE_FORMAT
 114            "]>?%dM>?(\\n[" DEPTH_FORMAT "]+(%dM/4))\n",
 115            uid, uid, p, sup->uid, x_height);
 116     // 18d
 117     if (sub != 0) {
 118       printf(".nr " SUB_LOWER_FORMAT " \\n[" SUB_LOWER_FORMAT "]>?%dM\n",
 119            uid, uid, sub2);
 120       // 18e
 121       printf(".nr " TEMP_REG " \\n[" DEPTH_FORMAT "]-\\n["
 122              SUP_RAISE_FORMAT "]+\\n[" HEIGHT_FORMAT "]-\\n["
 123              SUB_LOWER_FORMAT "]+(4*%dM)\n",
 124              sup->uid, uid, sub->uid, uid, default_rule_thickness);
 125       printf(".if \\n[" TEMP_REG "] \\{");
 126       printf(".nr " SUB_LOWER_FORMAT " +\\n[" TEMP_REG "]\n", uid);
 127       printf(".nr " TEMP_REG " (%dM*4/5)-\\n[" SUP_RAISE_FORMAT
 128              "]+\\n[" DEPTH_FORMAT "]>?0\n",
 129              x_height, uid, sup->uid);
 130       printf(".nr " SUP_RAISE_FORMAT " +\\n[" TEMP_REG "]\n", uid);
 131       printf(".nr " SUB_LOWER_FORMAT " -\\n[" TEMP_REG "]\n", uid);
 132       printf(".\\}\n");
 133     }
 134   }
 135   printf(".nr " WIDTH_FORMAT " 0\\n[" WIDTH_FORMAT "]", uid, p->uid);
 136   if (sub != 0 && sup != 0)
 137     printf("+((\\n[" WIDTH_FORMAT "]-\\n[" SUB_KERN_FORMAT "]>?\\n["
 138            WIDTH_FORMAT "])+%dM)>?0\n",
 139            sub->uid, p->uid, sup->uid, script_space);
 140   else if (sub != 0)
 141     printf("+(\\n[" WIDTH_FORMAT "]-\\n[" SUB_KERN_FORMAT "]+%dM)>?0\n",
 142            sub->uid, p->uid, script_space);
 143   else if (sup != 0)
 144     printf("+(\\n[" WIDTH_FORMAT "]+%dM)>?0\n", sup->uid, script_space);
 145   else
 146     printf("\n");
 147   printf(".nr " HEIGHT_FORMAT " \\n[" HEIGHT_FORMAT "]",
 148          uid, p->uid);
 149   if (sup != 0)
 150     printf(">?(\\n[" SUP_RAISE_FORMAT "]+\\n[" HEIGHT_FORMAT "])",
 151            uid, sup->uid);
 152   if (sub != 0)
 153     printf(">?(-\\n[" SUB_LOWER_FORMAT "]+\\n[" HEIGHT_FORMAT "])",
 154            uid, sub->uid);
 155   printf("\n");
 156   printf(".nr " DEPTH_FORMAT " \\n[" DEPTH_FORMAT "]",
 157          uid, p->uid);
 158   if (sub != 0)
 159     printf(">?(\\n[" SUB_LOWER_FORMAT "]+\\n[" DEPTH_FORMAT "])",
 160            uid, sub->uid);
 161   if (sup != 0)
 162     printf(">?(-\\n[" SUP_RAISE_FORMAT "]+\\n[" DEPTH_FORMAT "])",
 163            uid, sup->uid);
 164   printf("\n");
 165   return res;
 166 }
 167
 168 void script_box::output()
 169 {
 170   p->output();
 171   if (sup != 0) {
 172     printf("\\Z" DELIMITER_CHAR);
 173     printf("\\v'-\\n[" SUP_RAISE_FORMAT "]u'", uid);
 174     printf("\\s[\\n[" SMALL_SIZE_FORMAT "]]", uid);
 175     sup->output();
 176     printf("\\s[\\n[" SIZE_FORMAT "]]", uid);
 177     printf(DELIMITER_CHAR);
 178   }
 179   if (sub != 0) {
 180     printf("\\Z" DELIMITER_CHAR);
 181     printf("\\v'\\n[" SUB_LOWER_FORMAT "]u'", uid);
 182     printf("\\s[\\n[" SMALL_SIZE_FORMAT "]]", uid);
 183     printf("\\h'-\\n[" SUB_KERN_FORMAT "]u'", p->uid);
 184     sub->output();
 185     printf("\\s[\\n[" SIZE_FORMAT "]]", uid);
 186     printf(DELIMITER_CHAR);
 187   }
 188   printf("\\h'\\n[" WIDTH_FORMAT "]u-\\n[" WIDTH_FORMAT "]u'",
 189          uid, p->uid);
 190 }
 191
 192 void script_box::hint(unsigned flags)
 193 {
 194   p->hint(flags & ~HINT_NEXT_IS_ITALIC);
 195 }
 196
 197 void script_box::debug_print()
 198 {
 199   fprintf(stderr, "{ ");
 200   p->debug_print();
 201   fprintf(stderr, " }");
 202   if (sub) {
 203     fprintf(stderr, " sub { ");
 204     sub->debug_print();
 205     fprintf(stderr, " }");
 206   }
 207   if (sup) {
 208     fprintf(stderr, " sup { ");
 209     sup->debug_print();
 210     fprintf(stderr, " }");
 211   }
 212 }
 213
 214 void script_box::check_tabs(int level)
 215 {
 216   if (sup)
 217     sup->check_tabs(level + 1);
 218   if (sub)
 219     sub->check_tabs(level + 1);
 220   p->check_tabs(level);
 221 }