font.c

   1 #include <fcntl.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <unistd.h>
   5 #include <string.h>
   6 #include "config.h"
   7 #include "font.h"
   8 #include "util.h"
   9
  10 static int fd;
  11 static int rows;
  12 static int cols;
  13 static int n;
  14 static int *glyphs;
  15
  16 /*
  17  * tinyfont format:
  18  *
  19  * sig[8]       "tinyfont"
  20  * ver          0
  21  * n            number of glyphs
  22  * rows         glyph rows
  23  * cols         glyph cols
  24  *
  25  * glyphs[n]    unicode character numbers (int)
  26  * bitmaps[n]   character bitmaps (char[rows * cols])
  27  */
  28 struct tinyfont {
  29         char sig[8];
  30         int ver;
  31         int n;
  32         int rows, cols;
  33 };
  34
  35 int font_init(void)
  36 {
  37         struct tinyfont head;
  38         fd = open(TINYFONT, O_RDONLY);
  39         if (fd == -1)
  40                 return 1;
  41         fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
  42         if (read(fd, &head, sizeof(head)) != sizeof(head))
  43                 return 1;
  44         n = head.n;
  45         rows = head.rows;
  46         cols = head.cols;
  47         glyphs = malloc(n * sizeof(int));
  48         if (read(fd, glyphs, n * sizeof(int)) != n * sizeof(int))
  49                 return 1;
  50         return 0;
  51 }
  52
  53 static int find_glyph(int c)
  54 {
  55         int l = 0;
  56         int h = n;
  57         while (l < h) {
  58                 int m = (l + h) / 2;
  59                 if (glyphs[m] == c)
  60                         return m;
  61                 if (c < glyphs[m])
  62                         h = m;
  63                 else
  64                         l = m + 1;
  65         }
  66         return -1;
  67 }
  68
  69 int font_bitmap(void *dst, int c)
  70 {
  71         int i = find_glyph(c);
  72         if (i < 0)
  73                 return 1;
  74         lseek(fd, sizeof(struct tinyfont) + n * sizeof(int) + i * rows * cols, 0);
  75         read(fd, dst, rows * cols);
  76         return 0;
  77 }
  78
  79 void font_free(void)
  80 {
  81         free(glyphs);
  82         close(fd);
  83 }
  84
  85 int font_rows(void)
  86 {
  87         return rows;
  88 }
  89
  90 int font_cols(void)
  91 {
  92         return cols;
  93 }