anarchy

Incremental & reversible chaos library. Generates pseudo-random numbers (not suitable for cryptographic or statistical applications) in a reversible and incremental manner.

Capabilities include:

• Reversible PRNG
• Reversible & incremental shuffling
• Reversible & incremental random distribution (items among ranges)

The core API is available in C, Python, Javascript, and Unity/C#, and includes:

• Reversible pseudo-random number generation:
  • prng and rev_prng the forward and reverse PRNG functions
  • lfsr as a simple non-reversible PRNG (Linear Feedback Shift Register)
• Distribution functions that turn PRNG outputs into more useful numbers (only in Python and Javascript for now):
  • udist for a uniform floating-point value between 0 and 1.
  • pgdist for a pseudo-gaussian value between 0 and 1.
  • idist for an integer between given min and max values.
  • expdist, and trexpdist for floating-point exponential and truncated exponential distributions
• Incremental & reversible shuffling:
  • cohort_shuffle and rev_cohort_shuffle for finding shuffled/unshuffled indices one-at-a-time.
• Incremental & reversible distribution:
  • distribution_portion - For N items distributed among K segments each of maximum size S, how many items are in segment k?
  • distribution_prior_sum - For N items distributed among K segments of maximum size S, how many of the items are in segments that preceed segment k?
  • distribution_segment - For N items distributed among K segments of maximum size S, which segment does item n get distributed to?

Core documentation

Full documentation for all core functions pulled directly from the Python implementation (applies to all implementations):

Core Documentation

Example code

Example code using the JavaScript implementation that demonstrates things to do with the library.

Examples

Unity Example

The unity/anarchy folder is a complete Unity project which includes a component implementation of the library and a simple demo component that uses it to shuffle tiles in a Tilemap. When it's running, you can left-click to advance to the next seed, or right-click to go back to the previous seed. The code in the Tilepicker component demonstrates how to use anarchy.

That said, I'm not a Unity expert and this probably isn't the right way to release the library; it seems like a plugin would be more appropriate, but I haven't yet figured out the details of building and deploying one. If you'd like to use anarchy more seriously in a Unity context, let me know (even just by opening an issue) and I can make that more of a priority.