libdriver/printer.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, 675 Mass Ave, Cambridge, MA 02139, USA. */
  20
  21 #include "driver.h"
  22
  23 printer *pr = 0;
  24
  25 font_pointer_list::font_pointer_list(font *f, font_pointer_list *fp)
  26 : p(f), next(fp)
  27 {
  28 }
  29
  30 printer::printer()
  31 : font_table(0), nfonts(0), font_list(0)
  32 {
  33 }
  34
  35 printer::~printer()
  36 {
  37   a_delete font_table;
  38   while (font_list) {
  39     font_pointer_list *tem = font_list;
  40     font_list = font_list->next;
  41     delete tem->p;
  42     delete tem;
  43   }
  44   if (ferror(stdout) || fflush(stdout) < 0)
  45     fatal("output error");
  46 }
  47
  48 void printer::load_font(int n, const char *nm)
  49 {
  50   assert(n >= 0);
  51   if (n >= nfonts) {
  52     if (nfonts == 0) {
  53       nfonts = 10;
  54       if (nfonts <= n)
  55         nfonts = n + 1;
  56       font_table = new font *[nfonts];
  57       for (int i = 0; i < nfonts; i++)
  58         font_table[i] = 0;
  59     }
  60     else {
  61       font **old_font_table = font_table;
  62       int old_nfonts = nfonts;
  63       nfonts *= 2;
  64       if (n >= nfonts)
  65         nfonts = n + 1;
  66       font_table = new font *[nfonts];
  67       for (int i = 0; i < old_nfonts; i++)
  68         font_table[i] = old_font_table[i];
  69       for (i = old_nfonts; i < nfonts; i++)
  70         font_table[i] = 0;
  71       a_delete old_font_table;
  72     }
  73   }
  74   font *f = find_font(nm);
  75   font_table[n] = f;
  76 }
  77
  78 font *printer::find_font(const char *nm)
  79 {
  80   for (font_pointer_list *p = font_list; p; p = p->next)
  81     if (strcmp(p->p->get_name(), nm) == 0)
  82       return p->p;
  83   font *f = make_font(nm);
  84   if (!f)
  85     fatal("sorry, I can't continue");
  86   font_list = new font_pointer_list(f, font_list);
  87   return f;
  88 }
  89
  90 font *printer::make_font(const char *nm)
  91 {
  92   return font::load_font(nm);
  93 }
  94
  95 void printer::end_of_line()
  96 {
  97 }
  98
  99 void printer::special(char *, const environment *)
 100 {
 101 }
 102
 103 void printer::draw(int, int *, int, const environment *)
 104 {
 105 }
 106
 107 void printer::set_ascii_char(unsigned char c, const environment *env,
 108                              int *widthp)
 109 {
 110   char buf[2];
 111   buf[0] = c;
 112   buf[1] = '\0';
 113   set_special_char(buf, env, widthp);
 114 }
 115
 116 void printer::set_special_char(const char *nm, const environment *env,
 117                                   int *widthp)
 118 {
 119   int i = font::name_to_index(nm);
 120   int fn = env->fontno;
 121   if (fn < 0 || fn >= nfonts) {
 122     error("bad font position `%1'", fn);
 123     return;
 124   }
 125   font *f = font_table[fn];
 126   if (f == 0) {
 127     error("no font mounted at `%1'", fn);
 128     return;
 129   }
 130   if (!f->contains(i)) {
 131     if (nm[0] != '\0' && nm[1] == '\0')
 132       error("font `%1' does not contain ascii character `%2'",
 133             f->get_name(),
 134             nm[0]);
 135     else
 136       error("font `%1' does not contain special character `%2'",
 137             f->get_name(),
 138             nm);
 139     return;
 140   }
 141   int w = f->get_width(i, env->size);
 142   if (widthp)
 143     *widthp = w;
 144   set_char(i, f, env, w);
 145 }
 146
 147 void printer::set_numbered_char(int num, const environment *env, int *widthp)
 148 {
 149   int i = font::number_to_index(num);
 150   int fn = env->fontno;
 151   if (fn < 0 || fn >= nfonts) {
 152     error("bad font position `%1'", fn);
 153     return;
 154   }
 155   font *f = font_table[fn];
 156   if (f == 0) {
 157     error("no font mounted at `%1'", fn);
 158     return;
 159   }
 160   if (!f->contains(i)) {
 161     error("font `%1' does not contain numbered character %2",
 162           f->get_name(),
 163           num);
 164     return;
 165   }
 166   int w = f->get_width(i, env->size);
 167   if (widthp)
 168     *widthp = w;
 169   set_char(i, f, env, w);
 170 }
 171
 172 // This utility function adjusts the specified center of the
 173 // arc so that it is equidistant between the specified start
 174 // and end points. (p[0], p[1]) is a vector from the current
 175 // point to the center; (p[2], p[3]) is a vector from the
 176 // center to the end point.  If the center can be adjusted,
 177 // a vector from the current point to the adjusted center is
 178 // stored in c[0], c[1] and 1 is returned.  Otherwise 0 is
 179 // returned.
 180
 181 #if 1
 182 int printer::adjust_arc_center(const int *p, double *c)
 183 {
 184   // We move the center along a line parallel to the line between
 185   // the specified start point and end point so that the center
 186   // is equidistant between the start and end point.
 187   // It can be proved (using Lagrange multipliers) that this will
 188   // give the point nearest to the specified center that is equidistant
 189   // between the start and end point.
 190
 191   double x = p[0] + p[2];       // (x, y) is the end point
 192   double y = p[1] + p[3];
 193   double n = x*x + y*y;
 194   if (n != 0) {
 195     c[0]= double(p[0]);
 196     c[1] = double(p[1]);
 197     double k = .5 - (c[0]*x + c[1]*y)/n;
 198     c[0] += k*x;
 199     c[1] += k*y;
 200     return 1;
 201   }
 202   else
 203     return 0;
 204 }
 205 #else
 206 int printer::adjust_arc_center(const int *p, double *c)
 207 {
 208   int x = p[0] + p[2];  // (x, y) is the end point
 209   int y = p[1] + p[3];
 210   // Start at the current point; go in the direction of the specified
 211   // center point until we reach a point that is equidistant between
 212   // the specified starting point and the specified end point. Place
 213   // the center of the arc there.
 214   double n = p[0]*double(x) + p[1]*double(y);
 215   if (n > 0) {
 216     double k = (double(x)*x + double(y)*y)/(2.0*n);
 217     // (cx, cy) is our chosen center
 218     c[0] = k*p[0];
 219     c[1] = k*p[1];
 220     return 1;
 221   }
 222   else {
 223     // We would never reach such a point.  So instead start at the
 224     // specified end point of the arc.  Go towards the specified
 225     // center point until we reach a point that is equidistant between
 226     // the specified start point and specified end point. Place
 227     // the center of the arc there.
 228     n = p[2]*double(x) + p[3]*double(y);
 229     if (n > 0) {
 230       double k = 1 - (double(x)*x + double(y)*y)/(2.0*n);
 231       // (c[0], c[1]) is our chosen center
 232       c[0] = p[0] + k*p[2];
 233       c[1] = p[1] + k*p[3];
 234       return 1;
 235     }
 236     else
 237       return 0;
 238   }
 239 }
 240 #endif