unihexpose.c

/**
   @file: unihetranspose.c
 
   @brief: Transpose Unifont glyph bitmaps.
 
   This program takes Unifont .hex format glyphs and converts those
   glyphs so that each byte (two hexadecimal digits in the .hex file)
   represents a column of 8 rows.  This simplifies use with graphics
   display controllers that write lines consisting of 8 rows at a time
   to a display.
 
   The bytes are ordered as first all the columns for the glyph in
   the first 8 rows, then all the columns in the next 8 rows, with
   columns ordered from left to right.
 
   This file must be linked with functions in unifont-support.c.
 
   @author Paul Hardy
 
   @copyright Copyright © 2023 Paul Hardy
*/
/*
   LICENSE:
 
      This program is free software: you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published by
      the Free Software Foundation, either version 2 of the License, or
      (at your option) any later version.
 
      This program is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      GNU General Public License for more details.
 
      You should have received a copy of the GNU General Public License
      along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <stdlib.h>
 
#define MAXWIDTH 128
 
int
main (int argc, char *argv[]) {
   unsigned codept;     /* Unicode code point for glyph */
   char instring [MAXWIDTH];   /* input Unifont hex string */
   char outstring [MAXWIDTH];  /* output Unfont hex string */
   int  width;          /* width of current glyph */
   unsigned char glyph     [16][2];
   unsigned char glyphbits [16][16];  /* One glyphbits row, for transposing */
   unsigned char transpose [2][16];  /* Transponsed glyphbits bitmap   */
 
   void print_syntax ();
 
   void parse_hex (char *hexstring,
                   int *width,
                   unsigned *codept,
                   unsigned char glyph[16][2]);
 
   void glyph2bits (int width, 
                    unsigned char glyph[16][2],
                    unsigned char glyphbits [16][16]);
 
   void hexpose (int  width,
                 unsigned char glyphbits [16][16],
                 unsigned char transpose [2][16]);
 
   void xglyph2string (int width, unsigned codept,
                       unsigned char transpose [2][16],
                       char *outstring);
 
   if (argc > 1) {
      print_syntax ();
      exit (EXIT_FAILURE);
   }
 
   while (fgets (instring, MAXWIDTH, stdin) != NULL) {
      parse_hex (instring, &width, &codept, glyph);
 
      glyph2bits (width, glyph, glyphbits);
 
      hexpose (width, glyphbits, transpose);
 
      xglyph2string (width, codept, transpose, outstring);
 
      fprintf (stdout, "%s\n", outstring);
   }
 
   exit (EXIT_SUCCESS);
}
 
 
void
print_syntax () {
 
   fprintf (stderr, "\nSyntax: unihexpose < input.hex > output.hex\n\n");
 
   return;
}