eqn/sqrt.cc

   1 // -*- C++ -*-
   2 /* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
   3      Written by James Clark (jjc@jclark.com)
   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 2, 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 COPYING.  If not, write to the Free Software
  19 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
  20
  21 #include "eqn.h"
  22 #include "pbox.h"
  23
  24
  25 class sqrt_box : public pointer_box {
  26 public:
  27   sqrt_box(box *);
  28   int compute_metrics(int style);
  29   void output();
  30   void debug_print();
  31   void check_tabs(int);
  32 };
  33
  34 box *make_sqrt_box(box *pp)
  35 {
  36   return new sqrt_box(pp);
  37 }
  38
  39 sqrt_box::sqrt_box(box *pp) : pointer_box(pp)
  40 {
  41 }
  42
  43 #define SQRT_CHAR "\\(sr"
  44 #define RADICAL_EXTENSION_CHAR "\\[radicalex]"
  45
  46 #define SQRT_CHAIN "\\[sr\\\\n[" INDEX_REG "]]"
  47 #define BAR_CHAIN "\\[radicalex\\\\n[" INDEX_REG "]]"
  48
  49 int sqrt_box::compute_metrics(int style)
  50 {
  51   // 11
  52   int r = p->compute_metrics(cramped_style(style));
  53   printf(".nr " TEMP_REG " \\n[" HEIGHT_FORMAT "]+\\n[" DEPTH_FORMAT
  54          "]+%dM+(%dM/4)\n",
  55          p->uid, p->uid, default_rule_thickness,
  56          (style > SCRIPT_STYLE ? x_height : default_rule_thickness));
  57   printf(".nr " SIZE_FORMAT " \\n[.s]\n", uid);
  58   printf(".ds " SQRT_STRING_FORMAT " " SQRT_CHAR "\n", uid);
  59   printf(".ds " BAR_STRING " " RADICAL_EXTENSION_CHAR "\n");
  60   printf(".nr " SQRT_WIDTH_FORMAT
  61          " 0\\w" DELIMITER_CHAR SQRT_CHAR DELIMITER_CHAR "\n",
  62          uid);
  63   printf(".if \\n[rst]-\\n[rsb]-%dM<\\n[" TEMP_REG "] \\{",
  64          default_rule_thickness);
  65
  66   printf(".nr " INDEX_REG " 0\n"
  67          ".de " TEMP_MACRO "\n"
  68          ".ie c" SQRT_CHAIN " \\{"
  69          ".ds " SQRT_STRING_FORMAT " " SQRT_CHAIN "\n"
  70          ".ie c" BAR_CHAIN " .ds " BAR_STRING " " BAR_CHAIN "\n"
  71          ".el .ds " BAR_STRING " " RADICAL_EXTENSION_CHAR "\n"
  72          ".nr " SQRT_WIDTH_FORMAT
  73          " 0\\w" DELIMITER_CHAR SQRT_CHAIN DELIMITER_CHAR "\n"
  74          ".if \\\\n[rst]-\\\\n[rsb]-%dM<\\n[" TEMP_REG "] \\{"
  75          ".nr " INDEX_REG " +1\n"
  76          "." TEMP_MACRO "\n"
  77          ".\\}\\}\n"
  78          ".el .nr " INDEX_REG " 0-1\n"
  79          "..\n"
  80          "." TEMP_MACRO "\n",
  81          uid, uid, default_rule_thickness);
  82
  83   printf(".if \\n[" INDEX_REG "]<0 \\{");
  84
  85   // Determine the maximum point size
  86   printf(".ps 1000\n");
  87   printf(".nr " MAX_SIZE_REG " \\n[.s]\n");
  88   printf(".ps \\n[" SIZE_FORMAT "]\n", uid);
  89   // We define a macro that will increase the current point size
  90   // until we get a radical sign that's tall enough or we reach
  91   // the maximum point size.
  92   printf(".de " TEMP_MACRO "\n"
  93          ".nr " SQRT_WIDTH_FORMAT
  94          " 0\\w" DELIMITER_CHAR "\\*[" SQRT_STRING_FORMAT "]" DELIMITER_CHAR "\n"
  95          ".if \\\\n[rst]-\\\\n[rsb]-%dM<\\n[" TEMP_REG "]"
  96          "&(\\\\n[.s]<\\n[" MAX_SIZE_REG "]) \\{"
  97          ".ps +1\n"
  98          "." TEMP_MACRO "\n"
  99          ".\\}\n"
 100          "..\n"
 101          "." TEMP_MACRO "\n",
 102          uid, uid, default_rule_thickness);
 103
 104   printf(".\\}\\}\n");
 105
 106   printf(".nr " SMALL_SIZE_FORMAT " \\n[.s]\n", uid);
 107   // set TEMP_REG to the amount by which the radical sign is too big
 108   printf(".nr " TEMP_REG " \\n[rst]-\\n[rsb]-%dM-\\n[" TEMP_REG "]\n",
 109          default_rule_thickness);
 110   // If TEMP_REG is negative, the bottom of the radical sign should
 111   // be -TEMP_REG above the bottom of p. If it's positive, the bottom
 112   // of the radical sign should be TEMP_REG/2 below the bottom of p.
 113   // This calculates the amount by which the baseline of the radical
 114   // should be raised.
 115   printf(".nr " SUP_RAISE_FORMAT " (-\\n[" TEMP_REG "]>?(-\\n[" TEMP_REG "]/2))"
 116          "-\\n[rsb]-\\n[" DEPTH_FORMAT "]\n", uid, p->uid);
 117   printf(".nr " HEIGHT_FORMAT " \\n[" HEIGHT_FORMAT "]"
 118          ">?(\\n[" SUP_RAISE_FORMAT "]+\\n[rst])\n",
 119          uid, p->uid, uid);
 120   printf(".nr " DEPTH_FORMAT " \\n[" DEPTH_FORMAT "]"
 121          ">?(-\\n[" SUP_RAISE_FORMAT "]-\\n[rsb])\n",
 122          uid, p->uid, uid);
 123   // Do this last, so we don't lose height and depth information on
 124   // the radical sign.
 125   // Remember that the width of the bar might be greater than the width of p.
 126
 127   printf(".nr " TEMP_REG " "
 128          "\\n[" WIDTH_FORMAT "]"
 129          ">?\\w" DELIMITER_CHAR "\\*[" BAR_STRING "]" DELIMITER_CHAR "\n",
 130          p->uid);
 131   printf(".as " SQRT_STRING_FORMAT " "
 132          "\\l'\\n[" TEMP_REG "]u\\&\\*[" BAR_STRING "]'\n",
 133          uid);
 134   printf(".nr " WIDTH_FORMAT " \\n[" TEMP_REG "]"
 135          "+\\n[" SQRT_WIDTH_FORMAT "]\n",
 136          uid, uid);
 137
 138   if (r)
 139     printf(".nr " MARK_REG " +\\n[" SQRT_WIDTH_FORMAT "]\n", uid);
 140   // the top of the bar might be higher than the top of the radical sign
 141   printf(".nr " HEIGHT_FORMAT " \\n[" HEIGHT_FORMAT "]"
 142          ">?(\\n[" SUP_RAISE_FORMAT "]+\\n[rst])\n",
 143          uid, p->uid, uid);
 144   // put a bit of extra space above the bar
 145   printf(".nr " HEIGHT_FORMAT " +%dM\n", uid, default_rule_thickness);
 146   printf(".ps \\n[" SIZE_FORMAT "]\n", uid);
 147   return r;
 148 }
 149
 150 void sqrt_box::output()
 151 {
 152   printf("\\Z" DELIMITER_CHAR);
 153   printf("\\s[\\n[" SMALL_SIZE_FORMAT "]]", uid);
 154   printf("\\v'-\\n[" SUP_RAISE_FORMAT "]u'", uid);
 155   printf("\\*[" SQRT_STRING_FORMAT "]", uid);
 156   printf("\\s[\\n[" SIZE_FORMAT "]]", uid);
 157   printf(DELIMITER_CHAR);
 158
 159   printf("\\Z" DELIMITER_CHAR);
 160   printf("\\h'\\n[" WIDTH_FORMAT "]u-\\n[" WIDTH_FORMAT "]u"
 161          "+\\n[" SQRT_WIDTH_FORMAT "]u/2u'",
 162          uid, p->uid, uid);
 163   p->output();
 164   printf(DELIMITER_CHAR);
 165
 166   printf("\\h'\\n[" WIDTH_FORMAT "]u'", uid);
 167 }
 168
 169 void sqrt_box::debug_print()
 170 {
 171   fprintf(stderr, "sqrt { ");
 172   p->debug_print();
 173   fprintf(stderr, " }");
 174 }
 175
 176 void sqrt_box::check_tabs(int level)
 177 {
 178   p->check_tabs(level + 1);
 179 }