Line data    Source code

       1             : /* Copyright 1989-2024 Free Software Foundation, Inc.
       2             :      Written by James Clark (jjc@jclark.com)
       3             : 
       4             : This file is part of groff, the GNU roff typesetting system.
       5             : 
       6             : groff is free software; you can redistribute it and/or modify it under
       7             : the terms of the GNU General Public License as published by the Free
       8             : Software Foundation, either version 3 of the License, or
       9             : (at your option) any later version.
      10             : 
      11             : groff is distributed in the hope that it will be useful, but WITHOUT ANY
      12             : WARRANTY; without even the implied warranty of MERCHANTABILITY or
      13             : FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      14             : for more details.
      15             : 
      16             : You should have received a copy of the GNU General Public License
      17             : along with this program.  If not, see <http://www.gnu.org/licenses/>. */
      18             : 
      19             : #ifdef HAVE_CONFIG_H
      20             : #include <config.h>
      21             : #endif
      22             : 
      23             : #include "eqn.h"
      24             : #include "pbox.h"
      25             : 
      26             : #define STRING_FORMAT PREFIX "str%d"
      27             : 
      28             : #define SPECIAL_STRING "0s"
      29             : #define SPECIAL_WIDTH_REG "0w"
      30             : #define SPECIAL_HEIGHT_REG "0h"
      31             : #define SPECIAL_DEPTH_REG "0d"
      32             : #define SPECIAL_SUB_KERN_REG "0skern"
      33             : #define SPECIAL_SKEW_REG "0skew"
      34             : 
      35             : /*
      36             : For example:
      37             : 
      38             : .de Cl
      39             : .ds 0s \Z'\\*[0s]'\v'\\n(0du'\D'l \\n(0wu -\\n(0hu-\\n(0du'\v'\\n(0hu'
      40             : ..
      41             : .EQ
      42             : define cancel 'special Cl'
      43             : .EN
      44             : */
      45             : 
      46             : 
      47             : class special_box : public pointer_box {
      48             :   char *macro_name;
      49             : public:
      50             :   special_box(char *, box *);
      51             :   ~special_box();
      52             :   int compute_metrics(int);
      53             :   void compute_subscript_kern();
      54             :   void compute_skew();
      55             :   void output();
      56             :   void debug_print();
      57             : };
      58             : 
      59           0 : box *make_special_box(char *s, box *p)
      60             : {
      61           0 :   return new special_box(s, p);
      62             : }
      63             : 
      64           0 : special_box::special_box(char *s, box *pp) : pointer_box(pp), macro_name(s)
      65             : {
      66           0 : }
      67             : 
      68           0 : special_box::~special_box()
      69             : {
      70           0 :   delete[] macro_name;
      71           0 : }
      72             : 
      73           0 : int special_box::compute_metrics(int style)
      74             : {
      75           0 :   int r = p->compute_metrics(style);
      76           0 :   p->compute_subscript_kern();
      77           0 :   p->compute_skew();
      78           0 :   printf(".ds " SPECIAL_STRING " \"");
      79           0 :   p->output();
      80           0 :   printf("\n");
      81           0 :   printf(".nr " SPECIAL_WIDTH_REG " 0\\n[" WIDTH_FORMAT "]\n", p->uid);
      82           0 :   printf(".nr " SPECIAL_HEIGHT_REG " \\n[" HEIGHT_FORMAT "]\n", p->uid);
      83           0 :   printf(".nr " SPECIAL_DEPTH_REG " \\n[" DEPTH_FORMAT "]\n", p->uid);
      84           0 :   printf(".nr " SPECIAL_SUB_KERN_REG " \\n[" SUB_KERN_FORMAT "]\n", p->uid);
      85           0 :   printf(".nr " SPECIAL_SKEW_REG " 0\\n[" SKEW_FORMAT "]\n", p->uid);
      86           0 :   printf(".%s\n", macro_name);
      87           0 :   printf(".rn " SPECIAL_STRING " " STRING_FORMAT "\n", uid);
      88           0 :   printf(".nr " WIDTH_FORMAT " 0\\n[" SPECIAL_WIDTH_REG "]\n", uid);
      89           0 :   printf(".nr " HEIGHT_FORMAT " 0>?\\n[" SPECIAL_HEIGHT_REG "]\n", uid);
      90           0 :   printf(".nr " DEPTH_FORMAT " 0>?\\n[" SPECIAL_DEPTH_REG "]\n", uid);
      91           0 :   printf(".nr " SUB_KERN_FORMAT " 0>?\\n[" SPECIAL_SUB_KERN_REG "]\n", uid);
      92           0 :   printf(".nr " SKEW_FORMAT " 0\\n[" SPECIAL_SKEW_REG "]\n", uid);
      93             :   // User will have to change MARK_REG if appropriate.
      94           0 :   return r;
      95             : }
      96             : 
      97           0 : void special_box::compute_subscript_kern()
      98             : {
      99             :   // Already computed in compute_metrics(), so do nothing.
     100           0 : }
     101             : 
     102           0 : void special_box::compute_skew()
     103             : {
     104             :   // Already computed in compute_metrics(), so do nothing.
     105           0 : }
     106             : 
     107           0 : void special_box::output()
     108             : {
     109           0 :   if (output_format == troff)
     110           0 :     printf("\\*[" STRING_FORMAT "]", uid);
     111           0 :   else if (output_format == mathml)
     112           0 :     printf("<merror>eqn specials cannot be expressed in MathML</merror>");
     113           0 : }
     114             : 
     115           0 : void special_box::debug_print()
     116             : {
     117           0 :   fprintf(stderr, "special %s { ", macro_name);
     118           0 :   p->debug_print();
     119           0 :   fprintf(stderr, " }");
     120           0 : }
     121             : 
     122             : // Local Variables:
     123             : // fill-column: 72
     124             : // mode: C++
     125             : // End:
     126             : // vim: set cindent noexpandtab shiftwidth=2 textwidth=72: