Explore the Asset Packs to ship all game assets in a more compact way

[iWas-Coder]

https://www.youtube.com/watch?v=_k4TaZmSteY

Spec

https://github.com/sparky-game/skap-spec

This can be used for the release version of the game. So, every time that we interact with an asset, we need to do different things whether we are in debug mode or not:

• Debug :: load assets from original files (.e.g. assets/icon.png, assets/models/7mm.glb, etc.).
• Release :: load assets from Asset Pack (i.e. assets.skap), so they are pre-loaded in the way that the game uses them, no need to load them again (i.e. no need to call LoadModel("..."), just read the bytes from the Asset Pack and store them as a Model struct).

Header

[4 bytes] Signature -> "SKAP" (char signature[4])
[1 byte] Format version -> 1 (u8 fmt_ver)
[8 bytes] Build version -> 202405201829 (u64 build_ver)

static u64 concat_num(u64 x, u64 y) {
  u64 n = 10;
  while (y >= n) n *= 10;
  return n * x + y;
}

static u64 compute_build_ver(void) {
  time_t t = time(0);
  struct tm *t_spec = localtime(&t);
  u64 t_spec_arr[] = {
    t_spec->tm_mon + 1,
    t_spec->tm_mday,
    t_spec->tm_hour,
    t_spec->tm_min
  };
  u64 build_ver = t_spec->tm_year + 1900;
  for (size_t i = 0; i < 4; ++i) {
    if (t_spec_arr[i] < 10) build_ver *= 10;
    build_ver = concat_num(build_ver, t_spec_arr[i]);
  }
  return build_ver;
}

u64 build_ver = compute_build_ver();
printf("build_ver => %lld\n", build_ver);

Index

Types of assets:

• Images (LoadImage(...))
• Textures (LoadTexture(...))
• Sounds (LoadSound(...))
• Music (LoadMusic(...))
• Models (LoadModel(...))
• Shaders (???)

Important

The LoadTexture(...) function cannot be utilised, since it uploads the data directly to the GPU. We need to use for all image files the LoadImage(...) function instead.

Blob

The rest of binary data contained in a *.skap file appart from the Header and the Index.

Components

skap tool (serialization)

Asset Pack bundler tool, it ends up creating the assets.skap file.

sk_assetpack module (deserialization)

Asset Pack loader code, it loads the Header and the Index right away, then it retrieves data from the binary blob when requested.