src/pre-eqn/sqrt.cpp

   1 /*@
   2  * Copyright (c) 2014 - 2017 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
   3  *
   4  * Copyright (C) 1989 - 1992, 2002, 2003, 2007, 2008
   5  *    Free Software Foundation, Inc.
   6  *      Written by James Clark (jjc@jclark.com)
   7  *
   8  * This 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  * This 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 #define SQRT_CHAR               "\\[sqrt]"
  30 #define RADICAL_EXTENSION_CHAR  "\\[sqrtex]"
  31
  32 #define SQRT_CHAIN              "\\[sqrt\\\\n[" INDEX_REG "]]"
  33 #define BAR_CHAIN               "\\[sqrtex\\\\n[" INDEX_REG "]]"
  34
  35 class sqrt_box
  36 : public pointer_box
  37 {
  38 public:
  39   sqrt_box(box *);
  40   int compute_metrics(int style);
  41   void output();
  42   void debug_print();
  43   void check_tabs(int);
  44 };
  45
  46 box *make_sqrt_box(box *pp)
  47 {
  48   return new sqrt_box(pp);
  49 }
  50
  51 sqrt_box::sqrt_box(box *pp) : pointer_box(pp)
  52 {
  53 }
  54
  55 int sqrt_box::compute_metrics(int style)
  56 {
  57   // 11
  58   int r = p->compute_metrics(cramped_style(style));
  59   printf(".nr " TEMP_REG " \\n[" HEIGHT_FORMAT "]+\\n[" DEPTH_FORMAT
  60          "]+%dM+(%dM/4)\n",
  61          p->uid, p->uid, default_rule_thickness,
  62          (style > SCRIPT_STYLE ? x_height : default_rule_thickness));
  63   printf(".nr " SIZE_FORMAT " \\n[.ps]\n", uid);
  64   printf(".ds " SQRT_STRING_FORMAT " " SQRT_CHAR "\n", uid);
  65   printf(".ds " BAR_STRING " " RADICAL_EXTENSION_CHAR "\n");
  66   printf(".nr " SQRT_WIDTH_FORMAT
  67          " 0\\w" DELIMITER_CHAR SQRT_CHAR DELIMITER_CHAR "\n",
  68          uid);
  69   printf(".if \\n[rst]-\\n[rsb]-%dM<\\n[" TEMP_REG "] \\{",
  70          default_rule_thickness);
  71
  72   printf(".nr " INDEX_REG " 0\n"
  73          ".de " TEMP_MACRO "\n"
  74          ".ie c" SQRT_CHAIN " \\{"
  75          ".ds " SQRT_STRING_FORMAT " " SQRT_CHAIN "\n"
  76          ".ie c" BAR_CHAIN " .ds " BAR_STRING " " BAR_CHAIN "\n"
  77          ".el .ds " BAR_STRING " " RADICAL_EXTENSION_CHAR "\n"
  78          ".nr " SQRT_WIDTH_FORMAT
  79          " 0\\w" DELIMITER_CHAR SQRT_CHAIN DELIMITER_CHAR "\n"
  80          ".if \\\\n[rst]-\\\\n[rsb]-%dM<\\n[" TEMP_REG "] \\{"
  81          ".nr " INDEX_REG " +1\n"
  82          "." TEMP_MACRO "\n"
  83          ".\\}\\}\n"
  84          ".el .nr " INDEX_REG " 0-1\n"
  85          "..\n"
  86          "." TEMP_MACRO "\n",
  87          uid, uid, default_rule_thickness);
  88
  89   printf(".if \\n[" INDEX_REG "]<0 \\{");
  90
  91   // Determine the maximum point size
  92   printf(".ps 1000\n");
  93   printf(".nr " MAX_SIZE_REG " \\n[.ps]\n");
  94   printf(".ps \\n[" SIZE_FORMAT "]u\n", uid);
  95   // We define a macro that will increase the current point size
  96   // until we get a radical sign that's tall enough or we reach
  97   // the maximum point size.
  98   printf(".de " TEMP_MACRO "\n"
  99          ".nr " SQRT_WIDTH_FORMAT
 100          " 0\\w" DELIMITER_CHAR "\\*[" SQRT_STRING_FORMAT "]" DELIMITER_CHAR "\n"
 101          ".if \\\\n[rst]"
 102          "&(\\\\n[rst]-\\\\n[rsb]-%dM<\\n[" TEMP_REG "])"
 103          "&(\\\\n[.ps]<\\n[" MAX_SIZE_REG "]) \\{"
 104          ".ps +1\n"
 105          "." TEMP_MACRO "\n"
 106          ".\\}\n"
 107          "..\n"
 108          "." TEMP_MACRO "\n",
 109          uid, uid, default_rule_thickness);
 110
 111   printf(".\\}\\}\n");
 112
 113   printf(".nr " SMALL_SIZE_FORMAT " \\n[.ps]\n", uid);
 114   // set TEMP_REG to the amount by which the radical sign is too big
 115   printf(".nr " TEMP_REG " \\n[rst]-\\n[rsb]-%dM-\\n[" TEMP_REG "]\n",
 116          default_rule_thickness);
 117   // If TEMP_REG is negative, the bottom of the radical sign should
 118   // be -TEMP_REG above the bottom of p. If it's positive, the bottom
 119   // of the radical sign should be TEMP_REG/2 below the bottom of p.
 120   // This calculates the amount by which the baseline of the radical
 121   // should be raised.
 122   printf(".nr " SUP_RAISE_FORMAT " (-\\n[" TEMP_REG "]>?(-\\n[" TEMP_REG "]/2))"
 123          "-\\n[rsb]-\\n[" DEPTH_FORMAT "]\n", uid, p->uid);
 124   printf(".nr " HEIGHT_FORMAT " \\n[" HEIGHT_FORMAT "]"
 125          ">?(\\n[" SUP_RAISE_FORMAT "]+\\n[rst])\n",
 126          uid, p->uid, uid);
 127   printf(".nr " DEPTH_FORMAT " \\n[" DEPTH_FORMAT "]"
 128          ">?(-\\n[" SUP_RAISE_FORMAT "]-\\n[rsb])\n",
 129          uid, p->uid, uid);
 130   // Do this last, so we don't lose height and depth information on
 131   // the radical sign.
 132   // Remember that the width of the bar might be greater than the width of p.
 133
 134   printf(".nr " TEMP_REG " "
 135          "\\n[" WIDTH_FORMAT "]"
 136          ">?\\w" DELIMITER_CHAR "\\*[" BAR_STRING "]" DELIMITER_CHAR "\n",
 137          p->uid);
 138   printf(".as " SQRT_STRING_FORMAT " "
 139          "\\l'\\n[" TEMP_REG "]u\\&\\*[" BAR_STRING "]'\n",
 140          uid);
 141   printf(".nr " WIDTH_FORMAT " \\n[" TEMP_REG "]"
 142          "+\\n[" SQRT_WIDTH_FORMAT "]\n",
 143          uid, uid);
 144
 145   if (r)
 146     printf(".nr " MARK_REG " +\\n[" SQRT_WIDTH_FORMAT "]\n", uid);
 147   // the top of the bar might be higher than the top of the radical sign
 148   printf(".nr " HEIGHT_FORMAT " \\n[" HEIGHT_FORMAT "]"
 149          ">?(\\n[" SUP_RAISE_FORMAT "]+\\n[rst])\n",
 150          uid, p->uid, uid);
 151   // put a bit of extra space above the bar
 152   printf(".nr " HEIGHT_FORMAT " +%dM\n", uid, default_rule_thickness);
 153   printf(".ps \\n[" SIZE_FORMAT "]u\n", uid);
 154   return r;
 155 }
 156
 157 void sqrt_box::output()
 158 {
 159   if (output_format == troff) {
 160     printf("\\Z" DELIMITER_CHAR);
 161     printf("\\s[\\n[" SMALL_SIZE_FORMAT "]u]", uid);
 162     printf("\\v'-\\n[" SUP_RAISE_FORMAT "]u'", uid);
 163     printf("\\*[" SQRT_STRING_FORMAT "]", uid);
 164     printf("\\s[\\n[" SIZE_FORMAT "]u]", uid);
 165     printf(DELIMITER_CHAR);
 166
 167     printf("\\Z" DELIMITER_CHAR);
 168     printf("\\h'\\n[" WIDTH_FORMAT "]u-\\n[" WIDTH_FORMAT "]u"
 169            "+\\n[" SQRT_WIDTH_FORMAT "]u/2u'",
 170            uid, p->uid, uid);
 171     p->output();
 172     printf(DELIMITER_CHAR);
 173
 174     printf("\\h'\\n[" WIDTH_FORMAT "]u'", uid);
 175   }
 176   else if (output_format == mathml) {
 177     printf("<msqrt>");
 178     p->output();
 179     printf("</msqrt>");
 180   }
 181 }
 182
 183 void sqrt_box::debug_print()
 184 {
 185   fprintf(stderr, "sqrt { ");
 186   p->debug_print();
 187   fprintf(stderr, " }");
 188 }
 189
 190 void sqrt_box::check_tabs(int level)
 191 {
 192   p->check_tabs(level + 1);
 193 }
 194
 195 // s-it2-mode