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

   1 /*      $NetBSD$        */
   2
   3 // -*- C++ -*-
   4 /* Copyright (C) 1989, 1990, 1991, 1992, 2002, 2003
   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
  28 class sqrt_box : public pointer_box {
  29 public:
  30   sqrt_box(box *);
  31   int compute_metrics(int style);
  32   void output();
  33   void debug_print();
  34   void check_tabs(int);
  35 };
  36
  37 box *make_sqrt_box(box *pp)
  38 {
  39   return new sqrt_box(pp);
  40 }
  41
  42 sqrt_box::sqrt_box(box *pp) : pointer_box(pp)
  43 {
  44 }
  45
  46 #define SQRT_CHAR "\\[sqrt]"
  47 #define RADICAL_EXTENSION_CHAR "\\[sqrtex]"
  48
  49 #define SQRT_CHAIN "\\[sqrt\\\\n[" INDEX_REG "]]"
  50 #define BAR_CHAIN "\\[sqrtex\\\\n[" INDEX_REG "]]"
  51
  52 int sqrt_box::compute_metrics(int style)
  53 {
  54   // 11
  55   int r = p->compute_metrics(cramped_style(style));
  56   printf(".nr " TEMP_REG " \\n[" HEIGHT_FORMAT "]+\\n[" DEPTH_FORMAT
  57          "]+%dM+(%dM/4)\n",
  58          p->uid, p->uid, default_rule_thickness,
  59          (style > SCRIPT_STYLE ? x_height : default_rule_thickness));
  60   printf(".nr " SIZE_FORMAT " \\n[.ps]\n", uid);
  61   printf(".ds " SQRT_STRING_FORMAT " " SQRT_CHAR "\n", uid);
  62   printf(".ds " BAR_STRING " " RADICAL_EXTENSION_CHAR "\n");
  63   printf(".nr " SQRT_WIDTH_FORMAT
  64          " 0\\w" DELIMITER_CHAR SQRT_CHAR DELIMITER_CHAR "\n",
  65          uid);
  66   printf(".if \\n[rst]-\\n[rsb]-%dM<\\n[" TEMP_REG "] \\{",
  67          default_rule_thickness);
  68
  69   printf(".nr " INDEX_REG " 0\n"
  70          ".de " TEMP_MACRO "\n"
  71          ".ie c" SQRT_CHAIN " \\{"
  72          ".ds " SQRT_STRING_FORMAT " " SQRT_CHAIN "\n"
  73          ".ie c" BAR_CHAIN " .ds " BAR_STRING " " BAR_CHAIN "\n"
  74          ".el .ds " BAR_STRING " " RADICAL_EXTENSION_CHAR "\n"
  75          ".nr " SQRT_WIDTH_FORMAT
  76          " 0\\w" DELIMITER_CHAR SQRT_CHAIN DELIMITER_CHAR "\n"
  77          ".if \\\\n[rst]-\\\\n[rsb]-%dM<\\n[" TEMP_REG "] \\{"
  78          ".nr " INDEX_REG " +1\n"
  79          "." TEMP_MACRO "\n"
  80          ".\\}\\}\n"
  81          ".el .nr " INDEX_REG " 0-1\n"
  82          "..\n"
  83          "." TEMP_MACRO "\n",
  84          uid, uid, default_rule_thickness);
  85
  86   printf(".if \\n[" INDEX_REG "]<0 \\{");
  87
  88   // Determine the maximum point size
  89   printf(".ps 1000\n");
  90   printf(".nr " MAX_SIZE_REG " \\n[.ps]\n");
  91   printf(".ps \\n[" SIZE_FORMAT "]u\n", uid);
  92   // We define a macro that will increase the current point size
  93   // until we get a radical sign that's tall enough or we reach
  94   // the maximum point size.
  95   printf(".de " TEMP_MACRO "\n"
  96          ".nr " SQRT_WIDTH_FORMAT
  97          " 0\\w" DELIMITER_CHAR "\\*[" SQRT_STRING_FORMAT "]" DELIMITER_CHAR "\n"
  98          ".if \\\\n[rst]-\\\\n[rsb]-%dM<\\n[" TEMP_REG "]"
  99          "&(\\\\n[.ps]<\\n[" MAX_SIZE_REG "]) \\{"
 100          ".ps +1\n"
 101          "." TEMP_MACRO "\n"
 102          ".\\}\n"
 103          "..\n"
 104          "." TEMP_MACRO "\n",
 105          uid, uid, default_rule_thickness);
 106
 107   printf(".\\}\\}\n");
 108
 109   printf(".nr " SMALL_SIZE_FORMAT " \\n[.ps]\n", uid);
 110   // set TEMP_REG to the amount by which the radical sign is too big
 111   printf(".nr " TEMP_REG " \\n[rst]-\\n[rsb]-%dM-\\n[" TEMP_REG "]\n",
 112          default_rule_thickness);
 113   // If TEMP_REG is negative, the bottom of the radical sign should
 114   // be -TEMP_REG above the bottom of p. If it's positive, the bottom
 115   // of the radical sign should be TEMP_REG/2 below the bottom of p.
 116   // This calculates the amount by which the baseline of the radical
 117   // should be raised.
 118   printf(".nr " SUP_RAISE_FORMAT " (-\\n[" TEMP_REG "]>?(-\\n[" TEMP_REG "]/2))"
 119          "-\\n[rsb]-\\n[" DEPTH_FORMAT "]\n", uid, p->uid);
 120   printf(".nr " HEIGHT_FORMAT " \\n[" HEIGHT_FORMAT "]"
 121          ">?(\\n[" SUP_RAISE_FORMAT "]+\\n[rst])\n",
 122          uid, p->uid, uid);
 123   printf(".nr " DEPTH_FORMAT " \\n[" DEPTH_FORMAT "]"
 124          ">?(-\\n[" SUP_RAISE_FORMAT "]-\\n[rsb])\n",
 125          uid, p->uid, uid);
 126   // Do this last, so we don't lose height and depth information on
 127   // the radical sign.
 128   // Remember that the width of the bar might be greater than the width of p.
 129
 130   printf(".nr " TEMP_REG " "
 131          "\\n[" WIDTH_FORMAT "]"
 132          ">?\\w" DELIMITER_CHAR "\\*[" BAR_STRING "]" DELIMITER_CHAR "\n",
 133          p->uid);
 134   printf(".as " SQRT_STRING_FORMAT " "
 135          "\\l'\\n[" TEMP_REG "]u\\&\\*[" BAR_STRING "]'\n",
 136          uid);
 137   printf(".nr " WIDTH_FORMAT " \\n[" TEMP_REG "]"
 138          "+\\n[" SQRT_WIDTH_FORMAT "]\n",
 139          uid, uid);
 140
 141   if (r)
 142     printf(".nr " MARK_REG " +\\n[" SQRT_WIDTH_FORMAT "]\n", uid);
 143   // the top of the bar might be higher than the top of the radical sign
 144   printf(".nr " HEIGHT_FORMAT " \\n[" HEIGHT_FORMAT "]"
 145          ">?(\\n[" SUP_RAISE_FORMAT "]+\\n[rst])\n",
 146          uid, p->uid, uid);
 147   // put a bit of extra space above the bar
 148   printf(".nr " HEIGHT_FORMAT " +%dM\n", uid, default_rule_thickness);
 149   printf(".ps \\n[" SIZE_FORMAT "]u\n", uid);
 150   return r;
 151 }
 152
 153 void sqrt_box::output()
 154 {
 155   printf("\\Z" DELIMITER_CHAR);
 156   printf("\\s[\\n[" SMALL_SIZE_FORMAT "]u]", uid);
 157   printf("\\v'-\\n[" SUP_RAISE_FORMAT "]u'", uid);
 158   printf("\\*[" SQRT_STRING_FORMAT "]", uid);
 159   printf("\\s[\\n[" SIZE_FORMAT "]u]", uid);
 160   printf(DELIMITER_CHAR);
 161
 162   printf("\\Z" DELIMITER_CHAR);
 163   printf("\\h'\\n[" WIDTH_FORMAT "]u-\\n[" WIDTH_FORMAT "]u"
 164          "+\\n[" SQRT_WIDTH_FORMAT "]u/2u'",
 165          uid, p->uid, uid);
 166   p->output();
 167   printf(DELIMITER_CHAR);
 168
 169   printf("\\h'\\n[" WIDTH_FORMAT "]u'", uid);
 170 }
 171
 172 void sqrt_box::debug_print()
 173 {
 174   fprintf(stderr, "sqrt { ");
 175   p->debug_print();
 176   fprintf(stderr, " }");
 177 }
 178
 179 void sqrt_box::check_tabs(int level)
 180 {
 181   p->check_tabs(level + 1);
 182 }