tools/bmp_logo.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3
   4 #if defined(__linux__)
   5 #include <stdint.h>
   6 #else
   7 #ifdef __CYGWIN__
   8 #include "elf.h"
   9 #else
  10 #include <inttypes.h>
  11 #endif
  12 #endif
  13
  14 typedef struct bitmap_s {               /* bitmap description */
  15         uint16_t width;
  16         uint16_t height;
  17         uint8_t palette[256*3];
  18         uint8_t *data;
  19 } bitmap_t;
  20
  21 #define DEFAULT_CMAP_SIZE       16      /* size of default color map    */
  22
  23 /*
  24  * Neutralize little endians.
  25  */
  26 uint16_t le_short(uint16_t x)
  27 {
  28     uint16_t val;
  29     uint8_t *p = (uint8_t *)(&x);
  30
  31     val =  (*p++ & 0xff) << 0;
  32     val |= (*p & 0xff) << 8;
  33
  34     return val;
  35 }
  36
  37 void skip_bytes (FILE *fp, int n)
  38 {
  39         while (n-- > 0)
  40                 fgetc (fp);
  41 }
  42
  43 __attribute__ ((__noreturn__))
  44 int error (char * msg, FILE *fp)
  45 {
  46         fprintf (stderr, "ERROR: %s\n", msg);
  47
  48         fclose (fp);
  49
  50         exit (EXIT_FAILURE);
  51 }
  52
  53 int main (int argc, char *argv[])
  54 {
  55         int     i, x;
  56         FILE    *fp;
  57         bitmap_t bmp;
  58         bitmap_t *b = &bmp;
  59         uint16_t data_offset, n_colors;
  60
  61         if (argc < 2) {
  62                 fprintf (stderr, "Usage: %s file\n", argv[0]);
  63                 exit (EXIT_FAILURE);
  64         }
  65
  66         if ((fp = fopen (argv[1], "rb")) == NULL) {
  67                 perror (argv[1]);
  68                 exit (EXIT_FAILURE);
  69         }
  70
  71         if (fgetc (fp) != 'B' || fgetc (fp) != 'M')
  72                 error ("Input file is not a bitmap", fp);
  73
  74         /*
  75          * read width and height of the image, and the number of colors used;
  76          * ignore the rest
  77          */
  78         skip_bytes (fp, 8);
  79         if (fread (&data_offset, sizeof (uint16_t), 1, fp) != 1)
  80                 error ("Couldn't read bitmap data offset", fp);
  81         skip_bytes (fp, 6);
  82         if (fread (&b->width,   sizeof (uint16_t), 1, fp) != 1)
  83                 error ("Couldn't read bitmap width", fp);
  84         skip_bytes (fp, 2);
  85         if (fread (&b->height,  sizeof (uint16_t), 1, fp) != 1)
  86                 error ("Couldn't read bitmap height", fp);
  87         skip_bytes (fp, 22);
  88         if (fread (&n_colors, sizeof (uint16_t), 1, fp) != 1)
  89                 error ("Couldn't read bitmap colors", fp);
  90         skip_bytes (fp, 6);
  91
  92         /*
  93          * Repair endianess.
  94          */
  95         data_offset = le_short(data_offset);
  96         b->width = le_short(b->width);
  97         b->height = le_short(b->height);
  98         n_colors = le_short(n_colors);
  99
 100         /* assume we are working with an 8-bit file */
 101         if ((n_colors == 0) || (n_colors > 256 - DEFAULT_CMAP_SIZE)) {
 102                 /* reserve DEFAULT_CMAP_SIZE color map entries for default map */
 103                 n_colors = 256 - DEFAULT_CMAP_SIZE;
 104         }
 105
 106         printf ("/*\n"
 107                 " * Automatically generated by \"tools/bmp_logo\"\n"
 108                 " *\n"
 109                 " * DO NOT EDIT\n"
 110                 " *\n"
 111                 " */\n\n\n"
 112                 "#ifndef __BMP_LOGO_H__\n"
 113                 "#define __BMP_LOGO_H__\n\n"
 114                 "#define BMP_LOGO_WIDTH\t\t%d\n"
 115                 "#define BMP_LOGO_HEIGHT\t\t%d\n"
 116                 "#define BMP_LOGO_COLORS\t\t%d\n"
 117                 "#define BMP_LOGO_OFFSET\t\t%d\n"
 118                 "\n",
 119                 b->width, b->height, n_colors,
 120                 DEFAULT_CMAP_SIZE);
 121
 122         /* allocate memory */
 123         if ((b->data = (uint8_t *)malloc(b->width * b->height)) == NULL)
 124                 error ("Error allocating memory for file", fp);
 125
 126         /* read and print the palette information */
 127         printf ("unsigned short bmp_logo_palette[] = {\n");
 128
 129         for (i=0; i<n_colors; ++i) {
 130                 b->palette[(int)(i*3+2)] = fgetc(fp);
 131                 b->palette[(int)(i*3+1)] = fgetc(fp);
 132                 b->palette[(int)(i*3+0)] = fgetc(fp);
 133                 x=fgetc(fp);
 134
 135                 printf ("%s0x0%X%X%X,%s",
 136                         ((i%8) == 0) ? "\t" : "  ",
 137                         (b->palette[(int)(i*3+0)] >> 4) & 0x0F,
 138                         (b->palette[(int)(i*3+1)] >> 4) & 0x0F,
 139                         (b->palette[(int)(i*3+2)] >> 4) & 0x0F,
 140                         ((i%8) == 7) ? "\n" : ""
 141                 );
 142         }
 143
 144         /* seek to offset indicated by file header */
 145         fseek(fp, (long)data_offset, SEEK_SET);
 146
 147         /* read the bitmap; leave room for default color map */
 148         printf ("\n");
 149         printf ("};\n");
 150         printf ("\n");
 151         printf ("unsigned char bmp_logo_bitmap[] = {\n");
 152         for (i=(b->height-1)*b->width; i>=0; i-=b->width) {
 153                 for (x = 0; x < b->width; x++) {
 154                         b->data[(uint16_t) i + x] = (uint8_t) fgetc (fp) \
 155                                                 + DEFAULT_CMAP_SIZE;
 156                 }
 157         }
 158         fclose (fp);
 159
 160         for (i=0; i<(b->height*b->width); ++i) {
 161                 if ((i%8) == 0)
 162                         putchar ('\t');
 163                 printf ("0x%02X,%c",
 164                         b->data[i],
 165                         ((i%8) == 7) ? '\n' : ' '
 166                 );
 167         }
 168         printf ("\n"
 169                 "};\n\n"
 170                 "#endif /* __BMP_LOGO_H__ */\n"
 171         );
 172
 173         return (0);
 174 }