modules/unifont.c

   1 // This file is part of Deark.
   2 // Copyright (C) 2018 Jason Summers
   3 // See the file COPYING for terms of use.
   4
   5 // Unifont HEX font
   6
   7 #include <deark-config.h>
   8 #include <deark-private.h>
   9 DE_DECLARE_MODULE(de_module_unifont_hex);
  10
  11 struct de_linereader {
  12         dbuf *f;
  13         i64 f_pos;
  14 };
  15
  16 static struct de_linereader *de_linereader_create(deark *c, dbuf *f)
  17 {
  18         struct de_linereader *lr;
  19         lr = de_malloc(c, sizeof(struct de_linereader));
  20         lr->f = f;
  21         return lr;
  22 }
  23
  24 static void de_linereader_destroy(deark *c, struct de_linereader *lr)
  25 {
  26         if(!lr) return;
  27         de_free(c, lr);
  28 }
  29
  30 // TODO: Make the linereader more efficient and flexible, and make
  31 // it a standard library function.
  32 static int de_linereader_readnextline(deark *c, struct de_linereader *lr,
  33         char *buf, size_t buf_len, unsigned int flags)
  34 {
  35         int ret;
  36         i64 content_len = 0;
  37         i64 total_len = 0;
  38
  39         buf[0] = '\0';
  40
  41         ret = dbuf_find_line(lr->f, lr->f_pos, &content_len, &total_len);
  42         if(!ret) return 0;
  43         if(content_len > (i64)buf_len-1) {
  44                 lr->f_pos += total_len;
  45                 return 0;
  46         }
  47         dbuf_read(lr->f, (u8*)buf, lr->f_pos, content_len);
  48         buf[content_len] = '\0';
  49         lr->f_pos += total_len;
  50         return 1;
  51 }
  52
  53 static void decode_fontdata(deark *c, const char *hexdata,
  54         struct de_bitmap_font_char *ch)
  55 {
  56         i64 ndstbytes;
  57         i64 srcpos = 0;
  58         i64 dstpos = 0;
  59
  60         ndstbytes = ch->rowspan*ch->height;
  61         while(1) {
  62                 int errorflag;
  63                 u8 h0, h1;
  64
  65                 h0 = de_decode_hex_digit((unsigned char)hexdata[srcpos++], &errorflag);
  66                 if(errorflag) break;
  67                 h1 = de_decode_hex_digit((unsigned char)hexdata[srcpos++], &errorflag);
  68                 if(errorflag) break;
  69                 ch->bitmap[dstpos++] = (h0<<4)|h1;
  70                 if(dstpos>=ndstbytes) break;
  71         }
  72 }
  73
  74 static void de_run_unifont_hex(deark *c, de_module_params *mparams)
  75 {
  76         struct de_bitmap_font *font = NULL;
  77         i64 char_array_numalloc = 0;
  78         char linebuf[256];
  79         struct de_linereader *lr = NULL;
  80         int ok = 0;
  81
  82         font = de_create_bitmap_font(c);
  83         font->has_unicode_codepoints = 1;
  84         font->prefer_unicode = 1;
  85         font->nominal_height = 16;
  86         char_array_numalloc = 1024;
  87         font->char_array = de_mallocarray(c, char_array_numalloc, sizeof(struct de_bitmap_font_char));
  88
  89         lr = de_linereader_create(c, c->infile);
  90
  91         while(de_linereader_readnextline(c, lr, linebuf, sizeof(linebuf), 0)) {
  92                 i64 idx;
  93                 struct de_bitmap_font_char *ch;
  94                 i64 fdata_len;
  95                 char *dptr; // Pointer into linebuf, to the char after the ":"
  96
  97                 if(font->num_chars>=17*65536) goto done;
  98
  99                 idx = font->num_chars;
 100                 if(idx >= char_array_numalloc) {
 101                         i64 new_numalloc = char_array_numalloc*2;
 102                         font->char_array = de_reallocarray(c, font->char_array,
 103                                 char_array_numalloc, sizeof(struct de_bitmap_font_char),
 104                                 new_numalloc);
 105                         char_array_numalloc = new_numalloc;
 106                 }
 107                 ch = &font->char_array[idx];
 108
 109                 dptr = de_strchr(linebuf, ':');
 110                 if(!dptr) goto done;
 111                 *dptr = '\0';
 112                 dptr++;
 113
 114                 fdata_len = (i64)de_strlen(dptr);
 115                 ch->codepoint_unicode = (i32)de_strtoll(linebuf, NULL, 16);
 116                 if(ch->codepoint_unicode<0 || ch->codepoint_unicode>=17*65536) goto done;
 117
 118                 ch->width = (int)((fdata_len/32)*8);
 119                 ch->height = 16;
 120                 de_dbg2(c, "char[%d] U+%04X %d"DE_CHAR_TIMES"%d",
 121                         (int)font->num_chars, (unsigned int)ch->codepoint_unicode,
 122                         ch->width, ch->height);
 123                 if(ch->width<8 || ch->width>32) goto done;
 124                 ch->rowspan = (ch->width+7)/8;
 125                 ch->bitmap = de_malloc(c, ch->rowspan * ch->height);
 126                 decode_fontdata(c, dptr, ch);
 127
 128                 font->num_chars++;
 129                 if(ch->width > font->nominal_width) {
 130                         font->nominal_width = ch->width;
 131                 }
 132         }
 133
 134         de_dbg(c, "number of characters: %d", (int)font->num_chars);
 135         if(font->num_chars<1) goto done;
 136         if(font->nominal_width<1) goto done;
 137
 138         de_font_bitmap_font_to_image(c, font, NULL, 0);
 139         ok = 1;
 140
 141 done:
 142         if(!ok) {
 143                 de_err(c, "Error parsing HEX font file (offset %"I64_FMT")", lr->f_pos);
 144         }
 145         de_linereader_destroy(c, lr);
 146         if(font) {
 147                 if(font->char_array) {
 148                         i64 k;
 149                         for(k=0; k<font->num_chars; k++) {
 150                                 de_free(c, font->char_array[k].bitmap);
 151                         }
 152                         de_free(c, font->char_array);
 153                 }
 154                 font->char_array = NULL;
 155                 de_destroy_bitmap_font(c, font);
 156         }
 157 }
 158
 159 void de_module_unifont_hex(deark *c, struct deark_module_info *mi)
 160 {
 161         mi->id = "unifont_hex";
 162         mi->desc = "GNU Unifont HEX font";
 163         mi->run_fn = de_run_unifont_hex;
 164 }