mkarc

mkarc packs files into one archive, a file the program registers with package disc as one and reads with package archive, unpacking the entries it wants into memory of its own. The files named, and every file in each directory named, go in, in order:

$ mkarc -o assets/LEVEL.ARC pack/level
created "assets/LEVEL.ARC": 48,236 bytes from 119,320 (40%), 3 files, the largest BG.TIM at 65,556 bytes
  BG.TIM            65556 bytes, deflate, 31%
  CUBE.TIM           2112 bytes, deflate, 60%
  CUBE.TMD            344 bytes, deflate, 55%

Each entry is packed with deflate, unless that saves less than a tenth of it, as it does a sound bank or a movie, when it is stored as it is and the program can use it where it lies, with no copy; -s NAME stores one whatever it would pack to. Entries are named as the disc names files, in capitals, eight and three, from each file's name, so two files of a name cannot share an archive whatever their directories. -l lists an archive.

In a program, the archive is one declaration and one load, and each piece is unpacked when wanted, into an array of the program's own or into new memory:

var level = disc.Register("ASSETS/LEVEL.ARC", "assets/LEVEL.ARC")

a, err := archive.Open(level.Data())
e, ok := a.Lookup("CUBE.TMD")
words, err := e.Unpack(buf[:])   // or e.Load()
model := yaroze.TMD(words)

A scene draws from an archive through scene.NewArchive, as the scene example does with its textures and model. The format is format/archive's: a header, a table of entries with a method, the sizes and an offset each, then the entries' bytes, each starting on a word. Deflate is the one packing, chosen on measurements of the examples' data and of the decoders on the console; Compression has them. In the playground, "Pack into an archive" on a data file moves it under pack/NAME/ and adds the mkarc line that makes assets/NAME.ARC from that directory, so the archive is remade as its files change.