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 rows;
  12         int cols;
  13         int n;
  14         int *glyphs;
  15         char *data;
  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 static void *xread(int fd, int len)
  38 {
  39         void *buf = malloc(len);
  40         if (buf && read(fd, buf, len) == len)
  41                 return buf;
  42         free(buf);
  43         return NULL;
  44 }
  45
  46 struct font *font_open(char *path)
  47 {
  48         struct font *font;
  49         struct tinyfont head;
  50         int fd = open(path, O_RDONLY);
  51         if (fd < 0 || read(fd, &head, sizeof(head)) != sizeof(head)) {
  52                 close(fd);
  53                 return NULL;
  54         }
  55         font = malloc(sizeof(*font));
  56         font->n = head.n;
  57         font->rows = head.rows;
  58         font->cols = head.cols;
  59         font->glyphs = xread(fd, font->n * sizeof(int));
  60         font->data = xread(fd, font->n * font->rows * font->cols);
  61         close(fd);
  62         if (!font->glyphs || !font->data) {
  63                 font_free(font);
  64                 return NULL;
  65         }
  66         return font;
  67 }
  68
  69 static int find_glyph(struct font *font, int c)
  70 {
  71         int l = 0;
  72         int h = font->n;
  73         while (l < h) {
  74                 int m = (l + h) / 2;
  75                 if (font->glyphs[m] == c)
  76                         return m;
  77                 if (c < font->glyphs[m])
  78                         h = m;
  79                 else
  80                         l = m + 1;
  81         }
  82         return -1;
  83 }
  84
  85 int font_bitmap(struct font *font, void *dst, int c)
  86 {
  87         int i = find_glyph(font, c);
  88         int len = font->rows * font->cols;
  89         if (i < 0)
  90                 return 1;
  91         memcpy(dst, font->data + i * len, len);
  92         return 0;
  93 }
  94
  95 void font_free(struct font *font)
  96 {
  97         if (font->data)
  98                 free(font->data);
  99         if (font->glyphs)
 100                 free(font->glyphs);
 101         free(font);
 102 }
 103
 104 int font_rows(struct font *font)
 105 {
 106         return font->rows;
 107 }
 108
 109 int font_cols(struct font *font)
 110 {
 111         return font->cols;
 112 }