mbf.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <stdint.h>
   4 #include <string.h>
   5 #include <unistd.h>
   6 #include <sys/types.h>
   7 #include <sys/stat.h>
   8 #include <fcntl.h>
   9
  10 #include "mbf.h"
  11
  12 Font *
  13 load_font(const char *fname)
  14 {
  15     int fd;
  16     char sig[4];
  17     Header header;
  18     int stride;
  19     size_t ranges_size, data_size;
  20     Font *font;
  21
  22     fd = open(fname, O_RDONLY);
  23     if (fd == -1)
  24         return NULL;
  25     read(fd, sig, sizeof(sig));
  26     if (memcmp(sig, (char []) {'M', 'B', 'F', 0x01}, sizeof(sig))) {
  27         close(fd);
  28         return NULL;
  29     }
  30     read(fd, &header, sizeof(header));
  31     /* stride = ceil(w / 8) = floor(w / 8) + (w % 8 ? 1 : 0) */
  32     stride = (header.w >> 3) + !!(header.w & 7);
  33     ranges_size = header.nr * sizeof(Range);
  34     data_size = header.ng * stride * header.h;
  35     font = malloc(sizeof(Font) + ranges_size + data_size);
  36     if (!font) {
  37         close(fd);
  38         return NULL;
  39     }
  40     font->stride = stride;
  41     font->header = header;
  42     font->ranges = (Range *) &font[1];
  43     read(fd, font->ranges, ranges_size);
  44     font->data = (uint8_t *) &font->ranges[header.nr];
  45     read(fd, font->data, data_size);
  46     close(fd);
  47     return font;
  48 }
  49
  50 int
  51 search_glyph(Font *font, uint16_t code)
  52 {
  53     int index, i;
  54     Range r;
  55
  56     index = 0;
  57     for (i = 0; i < font->header.nr; i++) {
  58         r = font->ranges[i];
  59         if (code < r.offset)
  60             return -1;
  61         if (code < r.offset + r.length)
  62             return index + code - r.offset;
  63         index += r.length;
  64     }
  65     return -1;
  66 }
  67
  68 int
  69 get_index(Font *font, uint16_t code)
  70 {
  71     int index;
  72     uint16_t *cur_code;
  73     uint16_t codes[] = {code, 0xFFFD, 0x003F, 0x0020, 0};
  74
  75     for (cur_code = &codes[0]; *cur_code; cur_code++) {
  76         index = search_glyph(font, *cur_code);
  77         if (index != -1)
  78             break;
  79     };
  80     return index;
  81 }