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 struct font {
  11         int fd;
  12         int rows;
  13         int cols;
  14         int n;
  15         int *glyphs;
  16 };
  17
  18 /*
  19  * tinyfont format:
  20  *
  21  * sig[8]       "tinyfont"
  22  * ver          0
  23  * n            number of glyphs
  24  * rows         glyph rows
  25  * cols         glyph cols
  26  *
  27  * glyphs[n]    unicode character numbers (int)
  28  * bitmaps[n]   character bitmaps (char[rows * cols])
  29  */
  30 struct tinyfont {
  31         char sig[8];
  32         int ver;
  33         int n;
  34         int rows, cols;
  35 };
  36
  37 struct font *font_open(char *path)
  38 {
  39         struct font *font;
  40         struct tinyfont head;
  41         font = malloc(sizeof(*font));
  42         font->fd = open(path, O_RDONLY);
  43         if (font->fd == -1)
  44                 return NULL;
  45         fcntl(font->fd, F_SETFD, fcntl(font->fd, F_GETFD) | FD_CLOEXEC);
  46         if (read(font->fd, &head, sizeof(head)) != sizeof(head))
  47                 return NULL;
  48         font->n = head.n;
  49         font->rows = head.rows;
  50         font->cols = head.cols;
  51         font->glyphs = malloc(font->n * sizeof(int));
  52         if (read(font->fd, font->glyphs, font->n * sizeof(int)) != font->n * sizeof(int))
  53                 return NULL;
  54         return font;
  55 }
  56
  57 static int find_glyph(struct font *font, int c)
  58 {
  59         int l = 0;
  60         int h = font->n;
  61         while (l < h) {
  62                 int m = (l + h) / 2;
  63                 if (font->glyphs[m] == c)
  64                         return m;
  65                 if (c < font->glyphs[m])
  66                         h = m;
  67                 else
  68                         l = m + 1;
  69         }
  70         return -1;
  71 }
  72
  73 int font_bitmap(struct font *font, void *dst, int c)
  74 {
  75         int i = find_glyph(font, c);
  76         if (i < 0)
  77                 return 1;
  78         lseek(font->fd, sizeof(struct tinyfont) + font->n * sizeof(int) +
  79                                         i * font->rows * font->cols, 0);
  80         read(font->fd, dst, font->rows * font->cols);
  81         return 0;
  82 }
  83
  84 void font_free(struct font *font)
  85 {
  86         free(font->glyphs);
  87         close(font->fd);
  88         free(font);
  89 }
  90
  91 int font_rows(struct font *font)
  92 {
  93         return font->rows;
  94 }
  95
  96 int font_cols(struct font *font)
  97 {
  98         return font->cols;
  99 }