YAPF/docs/LANGUAGES.md
Claude a226b06368
YAPF 2: texture container with GPU blocks, wide samples and streaming
Adds format version 2 alongside version 1 (still written for plain 8-bit
images, so existing readers keep working). Full specification in
docs/FORMAT.md.

- GPU block payloads: BC1-BC7, BC6H, ETC2/EAC, ASTC 4x4-12x12, in tiles
  of 16x16 blocks. Built-in BC1/BC3/BC4/BC5/BC7/BC6H encoders and
  BC1-BC7 decoders (BC6H/BC7 bit-exact with a reference decoder).
- Lossless 16-bit, half and float pixels as byte planes over the 8-bit
  coder; order-preserving float mapping, transforms at sample width.
- Cubemaps, cube arrays, texture arrays, volumes, animation frames.
- Channel meanings, normal convention, linear mask, primaries/transfer,
  mip filter and coverage-preserving mips (yapf_tex_build_mips).
- Small mips stored first, file size in the header, surface/tile tables:
  decode from a file prefix and single tiles (virtual texturing).
- yapf-sum checksums on header, tables and every tile; needs bits so
  decoders refuse cleanly what they cannot read.
- Optional entropy stage: per-surface Huffman code books with a
  neighbourhood context (~10% smaller photos) and per-lane packing of
  GPU blocks (~3x smaller on disk); planes decoded interleaved.
- Notes: author, licence, source, tool, ICC and application tags.
- CLI: --format, --entropy, --coverage, --normal, --map, colour options,
  16-bit/HDR input, pack cube/array/volume/anim, info, verify, export.
- Tests for all of the above, including fuzzing; v1 API reads 8-bit v2.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DVrVthWN8GsmgHGUhhsCYm
2026-10-10 21:57:14 +00:00

5.7 KiB
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Using YAPF from your language

YAPF is a small C library with six functions, so every language that can call C can use it. Ready-made bindings, each with a runnable example:

Language Folder How it works Tested Decode¹
C yapf.h, examples/c the library itself ✅ 0.26 ms
C++ bindings/cpp header-only RAII wrapper (C++17) ✅ g++ 0.25 ms
Python bindings/python ctypes; numpy fallback without the library ✅ CPython 3.13 0.23 ms
C# / .NET bindings/csharp P/Invoke, single file ✅ .NET 8 0.30 ms
Rust bindings/rust crate, builds the C code with cc ✅ Rust 1.95 0.28 ms
Go bindings/go cgo package ✅ Go 1.26 0.31 ms
Java / Kotlin bindings/java Foreign Function & Memory API (Java 22+) ✅ JDK 25 0.42 ms
Zig bindings/zig @cImport of yapf.h ✅ Zig 0.16 0.28 ms
Lua bindings/lua LuaJIT FFI (also LÖVE) ✅ LuaJIT 2.1 0.28 ms
JavaScript / TypeScript bindings/js pure JS port, .d.ts types ✅ Node 24, Chromium 5.9 ms

¹ Decoding the 512×512 RGBA YAPF logo (other/YAPF.YAPF), best of 10 after a warm-up, on an AMD Ryzen 7 5700G. Every binding except JavaScript runs the same native code, so they are all about equally fast; the JavaScript port needs no native library at all. Every example also re-encodes the image and checks that the result is byte-identical to the original file.

YAPF 2 textures. The bindings wrap the version 1 API (yapf_load, yapf_save, …). Through it they also read 8-bit version 2 files (2D, or face 0 / layer 0 of cubes and arrays). GPU blocks, 16-bit / float pixels, volumes and the other version 2 features are available from C and C++ through the yapf_tex_* functions in yapf.h (see FORMAT.md); any language with a C FFI can call them the same way. The JavaScript port reads and writes version 1 only.

Getting the native library

Bindings other than C, C++, Rust, Go, Zig and JavaScript load the shared library at run time:

System File Get it
Windows yapf.dll Releases or build.bat
Linux libyapf.so Releases, make, or sudo make install
macOS libyapf.dylib Releases or make

Put it next to your program, on the library path (PATH, LD_LIBRARY_PATH, DYLD_LIBRARY_PATH), or pass its path explicitly (YAPF_LIBRARY for Python and Lua, -Dyapf.library= for Java).

Quick look

C

yapf_image_t *img = yapf_load("texture.yapf");
/* img->width, img->height, img->channels, img->pixels */
yapf_free(img);

C++

auto img = yapf::Image::load("texture.yapf");
auto bytes = img.encode();

Python

img = yapf.load("texture.yapf")
yapf.save("copy.yapf", img)

C#

var img = YapfImage.Load("texture.yapf");
File.WriteAllBytes("copy.yapf", img.Encode());

Rust

let img = yapf::Image::load("texture.yapf")?;
img.save("copy.yapf")?;

Go

img, err := yapf.Load("texture.yapf")
data, err := yapf.Encode(img)

Java

Yapf.Image img = Yapf.load(Path.of("texture.yapf"));
Yapf.save(Path.of("copy.yapf"), img);

Zig

const img = c.yapf_load("texture.yapf") orelse return error.CannotLoad;
defer c.yapf_free(img);

Lua

local img = yapf.load("texture.yapf")
yapf.save("copy.yapf", img)

JavaScript

const img = YAPF.decode(bytes);
const file = YAPF.encode(img);

Any other language

Swift, Kotlin/Native, Dart, PHP, Ruby, Julia, Nim, D, Odin, Haskell, … — anything with a C foreign-function interface can call the library directly. These are the whole API:

typedef struct {
    uint32_t  width, height;
    uint8_t   channels;     /* 1 gray, 2 gray+alpha, 3 RGB, 4 RGBA */
    uint8_t   gpu_format;   /* hint, see yapf.h */
    uint8_t   flags;        /* 1 premultiplied alpha, 2 sRGB */
    uint8_t   mip_levels;
    uint8_t  *pixels;       /* width*height*channels bytes, rows top to bottom */
    uint8_t **mips;         /* mips[0] == pixels */
} yapf_image_t;             /* 32 bytes on 64-bit systems: pixels at offset 16, mips at 24 */

yapf_image_t *yapf_load_memory_mt(const void *data, size_t size, int threads);  /* threads: 1 or 0 = all cores */
void          yapf_free(yapf_image_t *img);
int           yapf_encode(const yapf_image_t *img, void **out_data, size_t *out_size);
void          yapf_free_buffer(void *data);
yapf_image_t *yapf_load(const char *path);
int           yapf_save(const char *path, const yapf_image_t *img);

Returned images and buffers must be released with yapf_free / yapf_free_buffer from the same library. Ready-made bindings for these languages are not included yet; the snippets below show the starting point and are not tested.

Swift — add a module map for yapf.h (or a bridging header) and compile yapf.c in the target; then let img = yapf_load(path) works as is.

Dart — dart:ffi: DynamicLibrary.open('libyapf.so') and lookupFunction<Pointer<YapfImage> Function(Pointer<Uint8>, IntPtr, Int32), …>('yapf_load_memory_mt').

PHP 7.4+ — $ffi = FFI::cdef(file_get_contents('yapf_api.h'), 'libyapf.so'); with the declarations above in yapf_api.h.

Ruby — Fiddle::Function.new(lib['yapf_load'], [Fiddle::TYPE_VOIDP], Fiddle::TYPE_VOIDP).

Julia — ccall((:yapf_load, "libyapf"), Ptr{Cvoid}, (Cstring,), path).