message: gltfpack: Improve positional argument parsing
  Instead of assuming that input/output file names are the last two
  arguments, allow option specificaion anywhere in the command line.
diff: @@ -1382,24 +1382,14 @@ void writeU32(FILE* out, uint32_t data)
  int main(int argc, char** argv)
  {
  - if (argc < 3)
  - {
  - fprintf(stderr, "Usage: gltfpack [options] input output\n");
  - fprintf(stderr, "\n");
  - fprintf(stderr, "Options:\n");
  - fprintf(stderr, "-vpN: use N-bit quantization for position (default: 14; N should be between 1 and 16)\n");
  - fprintf(stderr, "-vtN: use N-bit quantization for texture corodinates (default: 12; N should be between 1 and 16)\n");
  - fprintf(stderr, "-c: produce compressed glb files\n");
  - fprintf(stderr, "-v: verbose output\n");
  -
  - return 1;
  - }
  -
  Settings settings = {};
  settings.pos_bits = 14;
  settings.uv_bits = 12;
  - for (int i = 1; i < argc - 2; ++i)
  + const char* input = 0;
  + const char* output = 0;
  +
  + for (int i = 1; i < argc; ++i)
  {
  const char* arg = argv[i];
  @@ -1419,15 +1409,39 @@ int main(int argc, char** argv)
  {
  settings.verbose = true;
  }
  + else if (arg[0] == '-')
  + {
  + fprintf(stderr, "Unrecognized option %s\n", arg);
  + return 1;
  + }
  + else if (!input)
  + {
  + input = arg;
  + }
  + else if (!output)
  + {
  + output = arg;
  + }
  else
  {
  - fprintf(stderr, "Unrecognized option %s\n", argv[i]);
  + fprintf(stderr, "Too many filenames, expected two\n");
  return 1;
  }
  }
  - const char* input = argv[argc - 2];
  - const char* output = argv[argc - 1];
  + if (!input || !output)
  + {
  + fprintf(stderr, "Usage: gltfpack [options] input output\n");
  + fprintf(stderr, "\n");
  + fprintf(stderr, "Options:\n");
  + fprintf(stderr, "-vpN: use N-bit quantization for position (default: 14; N should be between 1 and 16)\n");
  + fprintf(stderr, "-vtN: use N-bit quantization for texture corodinates (default: 12; N should be between 1 and 16)\n");
  + fprintf(stderr, "-c: produce compressed glb files\n");
  + fprintf(stderr, "-v: verbose output\n");
  +
  + return 1;
  + }
  +
  Scene scene = {};
  