agsalphahack.c

   1 #define _GNU_SOURCE
   2 #include "DataFile.h"
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6 #include "version.h"
   7 #define ADS ":::AGSalphahack " VERSION " by rofl0r:::"
   8
   9 static int usage(char *argv0) {
  10         dprintf(2, ADS "\nusage:\n%s [-s spriteno] DIR\n"
  11                    "removes alphachannel flag from specified sprite in game file.\n"
  12                    "if spriteno is -1 (default), all flags are removed.\n"
  13                    "gamefile is typically ac2game.dta or game28.dta inside DIR.\n"
  14                    "this is useful when sprites have been hacked/converted to 16bit.\n"
  15                    "you should make a backup of the file before doing this.\n"
  16                    , argv0);
  17         return 1;
  18 }
  19
  20 #define SPF_ALPHACHANNEL 0x10
  21
  22 int main(int argc, char**argv) {
  23         int c, flags = 0, spriteno = -1;
  24         while ((c = getopt(argc, argv, "s:")) != EOF) switch(c) {
  25                 case 's': spriteno = atoi(optarg); break;
  26                 default: return usage(argv[0]);
  27         }
  28         if(!argv[optind]) return usage(argv[0]);
  29         char *dir = argv[optind];
  30
  31         ADF a_b, *a = &a_b;
  32         char fnbuf[512];
  33         if(!ADF_find_datafile(dir, fnbuf, sizeof(fnbuf)))
  34                 return 1;
  35         if(!ADF_open(a, fnbuf)) return 1;
  36
  37         off_t off = ADF_get_spriteflagsstart(a);
  38         unsigned nsprites = ADF_get_spritecount(a);
  39         ADF_close(a);
  40
  41         printf("removing alpha of %u out of %u spriteflags.\n", spriteno==-1?nsprites:1, nsprites);
  42
  43         FILE *f = fopen(fnbuf, "r+b");
  44         if(!f) return 1;
  45         fseeko(f, off, SEEK_SET);
  46         unsigned char *buf = malloc(nsprites);
  47         fread(buf, 1, nsprites, f);
  48
  49         size_t i;
  50         for(i=0;i<nsprites;++i) {
  51                 if(spriteno == -1 || spriteno == i)
  52                         buf[i] = buf[i] & (~SPF_ALPHACHANNEL);
  53         }
  54         fseeko(f, off, SEEK_SET);
  55         fwrite(buf, 1, nsprites, f);
  56         fclose(f);
  57         free(buf);
  58         return 0;
  59 }