src/pre-eqn/special.cpp

   1 /*@
   2  * Copyright (c) 2014 - 2015 Steffen (Daode) Nurpmeso <sdaoden@users.sf.net>.
   3  *
   4  * Copyright (C) 1989 - 1992, 2007 Free Software Foundation, Inc.
   5  *      Written by James Clark (jjc@jclark.com)
   6  *
   7  * This 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  * This 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, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA.
  20  */
  21
  22 #include "config.h"
  23 #include "eqn-config.h"
  24
  25 #include "eqn.h"
  26 #include "pbox.h"
  27
  28 #define STRING_FORMAT PREFIX    "str%d"
  29
  30 #define SPECIAL_STRING          "0s"
  31 #define SPECIAL_WIDTH_REG       "0w"
  32 #define SPECIAL_HEIGHT_REG      "0h"
  33 #define SPECIAL_DEPTH_REG       "0d"
  34 #define SPECIAL_SUB_KERN_REG    "0skern"
  35 #define SPECIAL_SKEW_REG        "0skew"
  36
  37 /*
  38 For example:
  39
  40 .de Cl
  41 .ds 0s \Z'\\*[0s]'\v'\\n(0du'\D'l \\n(0wu -\\n(0hu-\\n(0du'\v'\\n(0hu'
  42 ..
  43 .EQ
  44 define cancel 'special Cl'
  45 .EN
  46 */
  47
  48 class special_box
  49 : public pointer_box
  50 {
  51   char *macro_name;
  52
  53 public:
  54   special_box(char *, box *);
  55   ~special_box();
  56   int compute_metrics(int);
  57   void compute_subscript_kern();
  58   void compute_skew();
  59   void output();
  60   void debug_print();
  61 };
  62
  63 box *make_special_box(char *s, box *p)
  64 {
  65   return new special_box(s, p);
  66 }
  67
  68 special_box::special_box(char *s, box *pp) : pointer_box(pp), macro_name(s)
  69 {
  70 }
  71
  72 special_box::~special_box()
  73 {
  74   a_delete macro_name;
  75 }
  76
  77 int special_box::compute_metrics(int style)
  78 {
  79   int r = p->compute_metrics(style);
  80   p->compute_subscript_kern();
  81   p->compute_skew();
  82   printf(".ds " SPECIAL_STRING " \"");
  83   p->output();
  84   printf("\n");
  85   printf(".nr " SPECIAL_WIDTH_REG " 0\\n[" WIDTH_FORMAT "]\n", p->uid);
  86   printf(".nr " SPECIAL_HEIGHT_REG " \\n[" HEIGHT_FORMAT "]\n", p->uid);
  87   printf(".nr " SPECIAL_DEPTH_REG " \\n[" DEPTH_FORMAT "]\n", p->uid);
  88   printf(".nr " SPECIAL_SUB_KERN_REG " \\n[" SUB_KERN_FORMAT "]\n", p->uid);
  89   printf(".nr " SPECIAL_SKEW_REG " 0\\n[" SKEW_FORMAT "]\n", p->uid);
  90   printf(".%s\n", macro_name);
  91   printf(".rn " SPECIAL_STRING " " STRING_FORMAT "\n", uid);
  92   printf(".nr " WIDTH_FORMAT " 0\\n[" SPECIAL_WIDTH_REG "]\n", uid);
  93   printf(".nr " HEIGHT_FORMAT " 0>?\\n[" SPECIAL_HEIGHT_REG "]\n", uid);
  94   printf(".nr " DEPTH_FORMAT " 0>?\\n[" SPECIAL_DEPTH_REG "]\n", uid);
  95   printf(".nr " SUB_KERN_FORMAT " 0>?\\n[" SPECIAL_SUB_KERN_REG "]\n", uid);
  96   printf(".nr " SKEW_FORMAT " 0\\n[" SPECIAL_SKEW_REG "]\n", uid);
  97   // User will have to change MARK_REG if appropriate.
  98   return r;
  99 }
 100
 101 void special_box::compute_subscript_kern()
 102 {
 103   // Already computed in compute_metrics(), so do nothing.
 104 }
 105
 106 void special_box::compute_skew()
 107 {
 108   // Already computed in compute_metrics(), so do nothing.
 109 }
 110
 111 void special_box::output()
 112 {
 113   if (output_format == troff)
 114     printf("\\*[" STRING_FORMAT "]", uid);
 115   else if (output_format == mathml)
 116     printf("<merror>eqn specials cannot be expressed in MathML</merror>");
 117 }
 118
 119 void special_box::debug_print()
 120 {
 121   fprintf(stderr, "special %s { ", macro_name);
 122   p->debug_print();
 123   fprintf(stderr, " }");
 124 }
 125
 126 // s-it2-mode