post.c

   1 /*
   2  * neatpost troff postscript postprocessor
   3  *
   4  * Copyright (C) 2013 Ali Gholami Rudi <ali at rudi dot ir>
   5  *
   6  * This program is released under the Modified BSD license.
   7  */
   8 #include <stdio.h>
   9 #include <ctype.h>
  10 #include "post.h"
  11
  12 static int o_pg;
  13
  14 static int next(void)
  15 {
  16         return getc(stdin);
  17 }
  18
  19 static void back(int c)
  20 {
  21         ungetc(c, stdin);
  22 }
  23
  24 static int utf8len(int c)
  25 {
  26         if (c <= 0x7f)
  27                 return 1;
  28         if (c >= 0xfc)
  29                 return 6;
  30         if (c >= 0xf8)
  31                 return 5;
  32         if (c >= 0xf0)
  33                 return 4;
  34         if (c >= 0xe0)
  35                 return 3;
  36         if (c >= 0xc0)
  37                 return 2;
  38         return 1;
  39 }
  40
  41 static int nextutf8(char *s)
  42 {
  43         int c = next();
  44         int l = utf8len(c);
  45         int i;
  46         if (c < 0)
  47                 return 0;
  48         s[0] = c;
  49         for (i = 1; i < l; i++)
  50                 s[i] = next();
  51         s[l] = '\0';
  52         return l;
  53 }
  54
  55 /* skip blanks */
  56 static void nextskip(void)
  57 {
  58         int c;
  59         do {
  60                 c = next();
  61         } while (isspace(c));
  62         back(c);
  63 }
  64
  65 static int nextnum(void)
  66 {
  67         int c;
  68         int n = 0;
  69         int neg = 0;
  70         nextskip();
  71         while (1) {
  72                 c = next();
  73                 if (!n && c == '-') {
  74                         neg = 1;
  75                         continue;
  76                 }
  77                 if (!isdigit(c))
  78                         back(c);
  79                 if (c < 0 || !isdigit(c))
  80                         break;
  81                 n = n * 10 + c - '0';
  82         }
  83         return neg ? -n : n;
  84 }
  85
  86 static int iseol(void)
  87 {
  88         int c;
  89         do {
  90                 c = next();
  91         } while (c == ' ');
  92         if (c != '\n')
  93                 back(c);
  94         return c == '\n';
  95 }
  96
  97 /* skip until the end of line */
  98 static void nexteol(void)
  99 {
 100         int c;
 101         do {
 102                 c = next();
 103         } while (c >= 0 && c != '\n');
 104 }
 105
 106 static void nextword(char *s)
 107 {
 108         int c;
 109         nextskip();
 110         c = next();
 111         while (c >= 0 && !isspace(c)) {
 112                 *s++ = c;
 113                 c = next();
 114         }
 115         if (c >= 0)
 116                 back(c);
 117         *s = '\0';
 118 }
 119
 120 static void postspline(int h1, int v1)
 121 {
 122         int h2, v2;
 123         while (!iseol()) {
 124                 h2 = nextnum();
 125                 v2 = nextnum();
 126                 draws(h1, v1, h2, v2);
 127                 h1 = h2;
 128                 v1 = v2;
 129         }
 130         draws(h1, v1, 0, 0);
 131 }
 132
 133 static void postdraw(void)
 134 {
 135         int h1, h2, v1, v2;
 136         int c = next();
 137         drawbeg();
 138         switch (c) {
 139         case 'l':
 140                 h1 = nextnum();
 141                 v1 = nextnum();
 142                 drawl(h1, v1);
 143                 break;
 144         case 'c':
 145                 drawc(nextnum());
 146                 break;
 147         case 'e':
 148                 h1 = nextnum();
 149                 v1 = nextnum();
 150                 drawe(h1, v1);
 151                 break;
 152         case 'a':
 153                 h1 = nextnum();
 154                 v1 = nextnum();
 155                 h2 = nextnum();
 156                 v2 = nextnum();
 157                 drawa(h1, v1, h2, v2);
 158                 break;
 159         case '~':
 160                 h1 = nextnum();
 161                 v1 = nextnum();
 162                 if (iseol())
 163                         drawl(h1, v1);
 164                 else
 165                         postspline(h1, v1);
 166                 break;
 167         }
 168         drawend();
 169         nexteol();
 170 }
 171
 172 static char devpath[PATHLEN] = "devutf";
 173
 174 static void postx(void)
 175 {
 176         char cmd[128];
 177         char dev[128];
 178         int pos;
 179         nextword(cmd);
 180         switch (cmd[0]) {
 181         case 'f':
 182                 pos = nextnum();
 183                 nextword(dev);
 184                 dev_mnt(pos, dev, dev);
 185                 break;
 186         case 'i':
 187                 dev_open(devpath);
 188                 break;
 189         case 'T':
 190                 nextword(dev);
 191                 sprintf(devpath, "%s/font/dev%s", TROFFROOT, dev);
 192                 break;
 193         case 's':
 194                 break;
 195         case 'X':
 196                 break;
 197         }
 198         nexteol();
 199 }
 200
 201 static void postcmd(int c)
 202 {
 203         char cs[GNLEN];
 204         if (isdigit(c)) {
 205                 outrel((c - '0') * 10 + next() - '0', 0);
 206                 nextutf8(cs);
 207                 outc(cs);
 208                 return;
 209         }
 210         switch (c) {
 211         case 's':
 212                 outsize(nextnum());
 213                 break;
 214         case 'f':
 215                 outfont(nextnum());
 216                 break;
 217         case 'H':
 218                 outh(nextnum());
 219                 break;
 220         case 'V':
 221                 outv(nextnum());
 222                 break;
 223         case 'h':
 224                 outrel(nextnum(), 0);
 225                 break;
 226         case 'v':
 227                 outrel(0, nextnum());
 228                 break;
 229         case 'c':
 230                 nextutf8(cs);
 231                 outc(cs);
 232                 break;
 233         case 'N':
 234                 nextnum();
 235                 break;
 236         case 'C':
 237                 nextword(cs);
 238                 outc(cs);
 239                 break;
 240         case 'p':
 241                 if (o_pg)
 242                         ps_pageend(o_pg);
 243                 o_pg = nextnum();
 244                 ps_pagebeg(o_pg);
 245                 outpage();
 246                 break;
 247         case 'w':
 248                 break;
 249         case 'n':
 250                 nextnum();
 251                 nextnum();
 252                 break;
 253         case 'D':
 254                 postdraw();
 255                 break;
 256         case 'x':
 257                 postx();
 258                 break;
 259         case '#':
 260                 nexteol();
 261                 break;
 262         default:
 263                 fprintf(stderr, "unknown command: %c\n", c);
 264         }
 265 }
 266
 267 static void post(void)
 268 {
 269         int c;
 270         while ((c = next()) >= 0)
 271                 if (!isspace(c))
 272                         postcmd(c);
 273         if (o_pg)
 274                 ps_pageend(o_pg);
 275 }
 276
 277 int main(void)
 278 {
 279         ps_header();
 280         post();
 281         ps_trailer(o_pg, o_fonts);
 282         return 0;
 283 }