font/manager.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2003,2005,2006,2007  Free Software Foundation, Inc.
   4  *
   5  *  GRUB is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  GRUB is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <grub/file.h>
  20 #include <grub/misc.h>
  21 #include <grub/dl.h>
  22 #include <grub/normal.h>
  23 #include <grub/types.h>
  24 #include <grub/mm.h>
  25 #include <grub/font.h>
  26 #include <grub/bufio.h>
  27
  28 struct entry
  29 {
  30   grub_uint32_t code;
  31   grub_uint32_t offset;
  32 };
  33
  34 struct font
  35 {
  36   struct font *next;
  37   grub_file_t file;
  38   grub_uint32_t num;
  39   struct entry table[0];
  40 };
  41
  42 static struct font *font_list;
  43
  44 /* Fill unknown glyph's with rounded question mark.  */
  45 static grub_uint8_t unknown_glyph[16] =
  46 {       /* 76543210 */
  47   0x7C, /*  ooooo   */
  48   0x82, /* o     o  */
  49   0xBA, /* o ooo o  */
  50   0xAA, /* o o o o  */
  51   0xAA, /* o o o o  */
  52   0x8A, /* o   o o  */
  53   0x9A, /* o  oo o  */
  54   0x92, /* o  o  o  */
  55   0x92, /* o  o  o  */
  56   0x92, /* o  o  o  */
  57   0x92, /* o  o  o  */
  58   0x82, /* o     o  */
  59   0x92, /* o  o  o  */
  60   0x82, /* o     o  */
  61   0x7C, /*  ooooo   */
  62   0x00  /*          */
  63 };
  64
  65 static int
  66 add_font (const char *filename)
  67 {
  68   grub_file_t file = 0;
  69   char magic[4];
  70   grub_uint32_t num, i;
  71   struct font *font = 0;
  72
  73   file = grub_buffile_open (filename, 0);
  74   if (! file)
  75     goto fail;
  76
  77   if (grub_file_read (file, magic, 4) != 4)
  78     goto fail;
  79
  80   if (grub_memcmp (magic, GRUB_FONT_MAGIC, 4) != 0)
  81     {
  82       grub_error (GRUB_ERR_BAD_FONT, "invalid font magic");
  83       goto fail;
  84     }
  85
  86   if (grub_file_read (file, (char *) &num, 4) != 4)
  87     goto fail;
  88
  89   num = grub_le_to_cpu32 (num);
  90   font = (struct font *) grub_malloc (sizeof (struct font)
  91                                       + sizeof (struct entry) * num);
  92   if (! font)
  93     goto fail;
  94
  95   font->file = file;
  96   font->num = num;
  97
  98   for (i = 0; i < num; i++)
  99     {
 100       grub_uint32_t code, offset;
 101
 102       if (grub_file_read (file, (char *) &code, 4) != 4)
 103         goto fail;
 104
 105       if (grub_file_read (file, (char *) &offset, 4) != 4)
 106         goto fail;
 107
 108       font->table[i].code = grub_le_to_cpu32 (code);
 109       font->table[i].offset = grub_le_to_cpu32 (offset);
 110     }
 111
 112   font->next = font_list;
 113   font_list = font;
 114
 115   return 1;
 116
 117  fail:
 118   if (font)
 119     grub_free (font);
 120
 121   if (file)
 122     grub_file_close (file);
 123
 124   return 0;
 125 }
 126
 127 static void
 128 remove_font (struct font *font)
 129 {
 130   struct font **p, *q;
 131
 132   for (p = &font_list, q = *p; q; p = &(q->next), q = q->next)
 133     if (q == font)
 134       {
 135         *p = q->next;
 136
 137         grub_file_close (font->file);
 138         grub_free (font);
 139
 140         break;
 141       }
 142 }
 143
 144 /* Return the offset of the glyph corresponding to the codepoint CODE
 145    in the font FONT.  If no found, return zero.  */
 146 static grub_uint32_t
 147 find_glyph (const struct font *font, grub_uint32_t code)
 148 {
 149   grub_uint32_t start = 0;
 150   grub_uint32_t end = font->num - 1;
 151   const struct entry *table = font->table;
 152
 153   /* This shouldn't happen.  */
 154   if (font->num == 0)
 155     return 0;
 156
 157   /* Do a binary search.  */
 158   while (start <= end)
 159     {
 160       grub_uint32_t i = (start + end) / 2;
 161
 162       if (table[i].code < code)
 163         start = i + 1;
 164       else if (table[i].code > code)
 165         end = i - 1;
 166       else
 167         return table[i].offset;
 168     }
 169
 170   return 0;
 171 }
 172
 173 /* Set the glyph to something stupid.  */
 174 static void
 175 fill_with_default_glyph (grub_font_glyph_t glyph)
 176 {
 177   unsigned i;
 178
 179   /* Use pre-defined pattern to fill unknown glyphs.  */
 180   for (i = 0; i < 16; i++)
 181     glyph->bitmap[i] = unknown_glyph[i];
 182
 183   glyph->char_width = 1;
 184   glyph->width = glyph->char_width * 8;
 185   glyph->height = 16;
 186   glyph->baseline = (16 * 3) / 4;
 187 }
 188
 189 /* Get a glyph corresponding to the codepoint CODE.  Always fill glyph
 190    information with something, even if no glyph is found.  */
 191 int
 192 grub_font_get_glyph (grub_uint32_t code,
 193                      grub_font_glyph_t glyph)
 194 {
 195   struct font *font;
 196   grub_uint8_t bitmap[32];
 197
 198   /* FIXME: It is necessary to cache glyphs!  */
 199
 200  restart:
 201   for (font = font_list; font; font = font->next)
 202     {
 203       grub_uint32_t offset;
 204
 205       offset = find_glyph (font, code);
 206       if (offset)
 207         {
 208           grub_uint32_t w;
 209           int len;
 210
 211           /* Make sure we can find glyphs for error messages.  Push active
 212              error message to error stack and reset error message.  */
 213           grub_error_push ();
 214
 215           grub_file_seek (font->file, offset);
 216           if ((len = grub_file_read (font->file, (char *) &w, sizeof (w)))
 217               != sizeof (w))
 218             {
 219               remove_font (font);
 220               goto restart;
 221             }
 222
 223           w = grub_le_to_cpu32 (w);
 224           if (w != 1 && w != 2)
 225             {
 226               /* grub_error (GRUB_ERR_BAD_FONT, "invalid width"); */
 227               remove_font (font);
 228               goto restart;
 229             }
 230
 231           if (grub_file_read (font->file, (char *) bitmap, w * 16)
 232               != (grub_ssize_t) w * 16)
 233             {
 234               remove_font (font);
 235               goto restart;
 236             }
 237
 238           /* Fill glyph with information.  */
 239           grub_memcpy (glyph->bitmap, bitmap, w * 16);
 240
 241           glyph->char_width = w;
 242           glyph->width = glyph->char_width * 8;
 243           glyph->height = 16;
 244           glyph->baseline = (16 * 3) / 4;
 245
 246           /* Restore old error message.  */
 247           grub_error_pop ();
 248
 249           return 1;
 250         }
 251     }
 252
 253   /* Uggh...  No font was found.  */
 254   fill_with_default_glyph (glyph);
 255   return 0;
 256 }
 257
 258 static grub_err_t
 259 font_command (struct grub_arg_list *state __attribute__ ((unused)),
 260               int argc  __attribute__ ((unused)),
 261               char **args __attribute__ ((unused)))
 262 {
 263   if (argc == 0)
 264     return grub_error (GRUB_ERR_BAD_ARGUMENT, "no font specified");
 265
 266   while (argc--)
 267     if (! add_font (*args++))
 268       return 1;
 269
 270   return 0;
 271 }
 272
 273 GRUB_MOD_INIT(font_manager)
 274 {
 275   grub_register_command ("font", font_command, GRUB_COMMAND_FLAG_BOTH,
 276                          "font FILE...",
 277                          "Specify one or more font files to display.", 0);
 278 }
 279
 280 GRUB_MOD_FINI(font_manager)
 281 {
 282   grub_unregister_command ("font");
 283 }