xxHash3 Len=8 Visualizer

AI Generated Visualizer finetuned for intuition not code quality

xxhash3.mov

Small standalone C/raylib program that visualizes the exact XXH3_64bits path used for one specific case:

• input text: "xxhash3!"
• input length: 8
• seed: 0
• secret source: the built-in XXH3 default secret

This repository is not an xxhash3 library and it does not implement the full family of XXH3 code paths. The app is an interactive teaching/inspection tool for the len=8 64-bit path only.

What The Program Shows

The program walks through the concrete values and bit-level transformations for:

1. Packing the 8-byte input into the input64 value used by the len=8 entry path.
2. Building the bitflip value from readLE64(secret + 8), readLE64(secret + 16), and seed'.
3. Computing keyed = input64 XOR bitflip.
4. Running the first XXH3_rrmxmx XOR/rotate stage.
5. Multiplying by PRIME_MX2.
6. Applying h ^= (h >> 35) + len.
7. Multiplying by PRIME_MX2 again.
8. Applying the final h ^= h >> 28.
9. Emitting the final 64-bit hash.
10. Showing a 64x64 avalanche grid for single-bit flips of the input64 value.

Most pages animate the operation step-by-step and let you hover bits or bytes to inspect how values move through the transform.

Pages

The UI has ten pages, selected with the top bar or number keys:

• 0: overview of the exact path and current concrete values
• 1: input packing and first keyed XOR (input64 XOR bitflip)
• 2: bitflip expansion from the default secret windows and seed adjustment
• 3: first rrmxmx XOR/rotate step
• 4: first multiply by PRIME_MX2
• 5: h ^= (h >> 35) + len
• 6: second multiply by PRIME_MX2
• 7: final h ^= h >> 28
• 8: returned 64-bit hash bytes and final value
• 9: avalanche grid for one-bit input flips

Requirements

• cc or another C compiler
• raylib
• optionally pkg-config

The Makefile first tries pkg-config --cflags raylib and pkg-config --libs raylib. If that fails, it falls back to:

-lraylib -lm -lpthread -ldl

That fallback is aimed at common Unix-like setups, but raylib still needs to be installed and linkable on your machine.

Build

make

This produces the executable:

./xxhash3_viz

Run

make run

Clean

make clean

Controls

• 0 through 9: switch pages
• click page buttons in the top bar: switch pages
• space: pause or resume the page animation
• r: reset the current page animation
• q: quit
• move the mouse over bits, bytes, secret windows, or avalanche cells: inspect mappings and intermediate values

Notes And Limitations

• The window starts at 1200x700, is resizable, and requests MSAA_4X.
• The window title is xxHash3 Visual - First Operation.
• The input text is currently hard-coded in src/main.c as "xxhash3!".
• The app is specific to the XXH3_64bits len=8 path. Other input lengths use different formulas and are not visualized here.
• The avalanche page flips bits in the derived input64 value for this path, not arbitrary-length byte strings.