src/pre-eqn/script.cpp

   1 /*@
   2  * Copyright (c) 2014 Steffen (Daode) Nurpmeso <sdaoden@users.sf.net>.
   3  *
   4  * Copyright (C) 1989 - 1992, 2002, 2004, 2007, 2008
   5  *    Free Software Foundation, Inc.
   6  *      Written by James Clark (jjc@jclark.com)
   7  *
   8  * groff is free software; you can redistribute it and/or modify it under
   9  * the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 2, or (at your option) any later
  11  * version.
  12  *
  13  * groff is distributed in the hope that it will be useful, but WITHOUT ANY
  14  * WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16  * for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with groff; see the file COPYING.  If not, write to the Free Software
  20  * Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA.
  21  */
  22
  23 #include "config.h"
  24 #include "eqn-config.h"
  25
  26 #include "eqn.h"
  27 #include "pbox.h"
  28
  29 class script_box
  30 : public pointer_box
  31 {
  32   box *sub;
  33   box *sup;
  34
  35 public:
  36   script_box(box *, box *, box *);
  37   ~script_box();
  38   int compute_metrics(int);
  39   void output();
  40   void debug_print();
  41   int left_is_italic();
  42   void hint(unsigned);
  43   void check_tabs(int);
  44 };
  45
  46 /* The idea is that the script should attach to the rightmost box
  47 of a list. For example, given `2x sup 3', the superscript should
  48 attach to `x' rather than `2x'. */
  49
  50 box *make_script_box(box *nuc, box *sub, box *sup)
  51 {
  52   list_box *b = nuc->to_list_box();
  53   if (b != 0) {
  54     b->list.p[b->list.len-1] = make_script_box(b->list.p[b->list.len - 1],
  55                                                sub,
  56                                                sup);
  57     return b;
  58   }
  59   else
  60     return new script_box(nuc, sub, sup);
  61 }
  62
  63 script_box::script_box(box *pp, box *qq, box *rr)
  64 : pointer_box(pp), sub(qq), sup(rr)
  65 {
  66 }
  67
  68 script_box::~script_box()
  69 {
  70   delete sub;
  71   delete sup;
  72 }
  73
  74 int script_box::left_is_italic()
  75 {
  76   return p->left_is_italic();
  77 }
  78
  79 int script_box::compute_metrics(int style)
  80 {
  81   int res = p->compute_metrics(style);
  82   p->compute_subscript_kern();
  83   printf(".nr " SIZE_FORMAT " \\n[.ps]\n", uid);
  84   if (!(style <= SCRIPT_STYLE && one_size_reduction_flag))
  85     set_script_size();
  86   printf(".nr " SMALL_SIZE_FORMAT " \\n[.ps]\n", uid);
  87   if (sub != 0)
  88     sub->compute_metrics(cramped_style(script_style(style)));
  89   if (sup != 0)
  90     sup->compute_metrics(script_style(style));
  91   // 18a
  92   if (p->is_char()) {
  93     printf(".nr " SUP_RAISE_FORMAT " 0\n", uid);
  94     printf(".nr " SUB_LOWER_FORMAT " 0\n", uid);
  95   }
  96   else {
  97     printf(".nr " SUP_RAISE_FORMAT " \\n[" HEIGHT_FORMAT "]-%dM>?0\n",
  98            uid, p->uid, sup_drop);
  99     printf(".nr " SUB_LOWER_FORMAT " \\n[" DEPTH_FORMAT "]+%dM\n",
 100            uid, p->uid, sub_drop);
 101   }
 102   printf(".ps \\n[" SIZE_FORMAT "]u\n", uid);
 103   if (sup == 0) {
 104     assert(sub != 0);
 105     // 18b
 106     printf(".nr " SUB_LOWER_FORMAT " \\n[" SUB_LOWER_FORMAT "]>?%dM>?(\\n["
 107            HEIGHT_FORMAT "]-(%dM*4/5))\n",
 108            uid, uid, sub1, sub->uid, x_height);
 109   }
 110   else {
 111     // sup != 0
 112     // 18c
 113     int pos;
 114     if (style == DISPLAY_STYLE)
 115       pos = sup1;
 116     else if (style & 1)         // not cramped
 117       pos = sup2;
 118     else
 119       pos = sup3;
 120     printf(".nr " SUP_RAISE_FORMAT " \\n[" SUP_RAISE_FORMAT
 121            "]>?%dM>?(\\n[" DEPTH_FORMAT "]+(%dM/4))\n",
 122            uid, uid, pos, sup->uid, x_height);
 123     // 18d
 124     if (sub != 0) {
 125       printf(".nr " SUB_LOWER_FORMAT " \\n[" SUB_LOWER_FORMAT "]>?%dM\n",
 126              uid, uid, sub2);
 127       // 18e
 128       printf(".nr " TEMP_REG " \\n[" DEPTH_FORMAT "]-\\n["
 129              SUP_RAISE_FORMAT "]+\\n[" HEIGHT_FORMAT "]-\\n["
 130              SUB_LOWER_FORMAT "]+(4*%dM)\n",
 131              sup->uid, uid, sub->uid, uid, default_rule_thickness);
 132       printf(".if \\n[" TEMP_REG "] \\{");
 133       printf(".nr " SUB_LOWER_FORMAT " +\\n[" TEMP_REG "]\n", uid);
 134       printf(".nr " TEMP_REG " (%dM*4/5)-\\n[" SUP_RAISE_FORMAT
 135              "]+\\n[" DEPTH_FORMAT "]>?0\n",
 136              x_height, uid, sup->uid);
 137       printf(".nr " SUP_RAISE_FORMAT " +\\n[" TEMP_REG "]\n", uid);
 138       printf(".nr " SUB_LOWER_FORMAT " -\\n[" TEMP_REG "]\n", uid);
 139       printf(".\\}\n");
 140     }
 141   }
 142   printf(".nr " WIDTH_FORMAT " 0\\n[" WIDTH_FORMAT "]", uid, p->uid);
 143   if (sub != 0 && sup != 0)
 144     printf("+((\\n[" WIDTH_FORMAT "]-\\n[" SUB_KERN_FORMAT "]>?\\n["
 145            WIDTH_FORMAT "])+%dM)>?0\n",
 146            sub->uid, p->uid, sup->uid, script_space);
 147   else if (sub != 0)
 148     printf("+(\\n[" WIDTH_FORMAT "]-\\n[" SUB_KERN_FORMAT "]+%dM)>?0\n",
 149            sub->uid, p->uid, script_space);
 150   else if (sup != 0)
 151     printf("+(\\n[" WIDTH_FORMAT "]+%dM)>?0\n", sup->uid, script_space);
 152   else
 153     printf("\n");
 154   printf(".nr " HEIGHT_FORMAT " \\n[" HEIGHT_FORMAT "]",
 155          uid, p->uid);
 156   if (sup != 0)
 157     printf(">?(\\n[" SUP_RAISE_FORMAT "]+\\n[" HEIGHT_FORMAT "])",
 158            uid, sup->uid);
 159   if (sub != 0)
 160     printf(">?(-\\n[" SUB_LOWER_FORMAT "]+\\n[" HEIGHT_FORMAT "])",
 161            uid, sub->uid);
 162   printf("\n");
 163   printf(".nr " DEPTH_FORMAT " \\n[" DEPTH_FORMAT "]",
 164          uid, p->uid);
 165   if (sub != 0)
 166     printf(">?(\\n[" SUB_LOWER_FORMAT "]+\\n[" DEPTH_FORMAT "])",
 167            uid, sub->uid);
 168   if (sup != 0)
 169     printf(">?(-\\n[" SUP_RAISE_FORMAT "]+\\n[" DEPTH_FORMAT "])",
 170            uid, sup->uid);
 171   printf("\n");
 172   return res;
 173 }
 174
 175 void script_box::output()
 176 {
 177   if (output_format == troff) {
 178     p->output();
 179     if (sup != 0) {
 180       printf("\\Z" DELIMITER_CHAR);
 181       printf("\\v'-\\n[" SUP_RAISE_FORMAT "]u'", uid);
 182       printf("\\s[\\n[" SMALL_SIZE_FORMAT "]u]", uid);
 183       sup->output();
 184       printf("\\s[\\n[" SIZE_FORMAT "]u]", uid);
 185       printf(DELIMITER_CHAR);
 186     }
 187     if (sub != 0) {
 188       printf("\\Z" DELIMITER_CHAR);
 189       printf("\\v'\\n[" SUB_LOWER_FORMAT "]u'", uid);
 190       printf("\\s[\\n[" SMALL_SIZE_FORMAT "]u]", uid);
 191       printf("\\h'-\\n[" SUB_KERN_FORMAT "]u'", p->uid);
 192       sub->output();
 193       printf("\\s[\\n[" SIZE_FORMAT "]u]", uid);
 194       printf(DELIMITER_CHAR);
 195     }
 196     printf("\\h'\\n[" WIDTH_FORMAT "]u-\\n[" WIDTH_FORMAT "]u'",
 197            uid, p->uid);
 198   }
 199   else if (output_format == mathml) {
 200     if (sup != 0 && sub != 0) {
 201       printf("<msubsup>");
 202       p->output();
 203       sub->output();
 204       sup->output();
 205       printf("</msubsup>");
 206     }
 207     else if (sup != 0) {
 208       printf("<msup>");
 209       p->output();
 210       sup->output();
 211       printf("</msup>");
 212   }
 213   else if (sub != 0) {
 214       printf("<msub>");
 215       p->output();
 216       sub->output();
 217       printf("</msub>");
 218     }
 219   }
 220 }
 221
 222 void script_box::hint(unsigned flags)
 223 {
 224   p->hint(flags & ~HINT_NEXT_IS_ITALIC);
 225 }
 226
 227 void script_box::debug_print()
 228 {
 229   fprintf(stderr, "{ ");
 230   p->debug_print();
 231   fprintf(stderr, " }");
 232   if (sub) {
 233     fprintf(stderr, " sub { ");
 234     sub->debug_print();
 235     fprintf(stderr, " }");
 236   }
 237   if (sup) {
 238     fprintf(stderr, " sup { ");
 239     sup->debug_print();
 240     fprintf(stderr, " }");
 241   }
 242 }
 243
 244 void script_box::check_tabs(int level)
 245 {
 246   if (sup)
 247     sup->check_tabs(level + 1);
 248   if (sub)
 249     sub->check_tabs(level + 1);
 250   p->check_tabs(level);
 251 }
 252
 253 // s-it2-mode