# Cornhole

> True 3D cornhole in the browser. The bag is modelled as a deformable resin-filled envelope with
> a distinct fast side and slow side, board and bag dimensions come from the ACO and ACL
> rulebooks, and scoring is cancellation to 21 with no bust rule (because neither governing body
> has one). Free, no account, nothing to install, no network calls.

URL: https://cornhole.skillsafe.ai/

## What it is
A single-page reimplementation of the codified sport of cornhole, written from the published
rulebooks of the American Cornhole Organization (ACO) and the American Cornhole League (ACL).
Singles play: four bags each, eight per frame, cancellation scoring, first to reach or exceed 21
at the end of a frame wins. Hand-written WebGL2, no libraries.

## The mechanic that makes it different
Competition cornhole bags have two faces of different material. The ACL's Set Uniformity rule
regulates this explicitly and names the materials - "a gray suede side and a red duck cloth side"
- so the two-faced bag is a rule, not folklore. Which face is faster, and by how much, is in NO
rulebook, so that part is reconstructed. In this game the player chooses the face down as a
fourth control alongside aim, power and loft, and it changes the shot completely: the suede side
slides on after landing (the shot that walks a bag up into the hole), the duck-cloth side stops
close to where it lands (the airmail and the blocker).

## Why the bag has to deform
A rigid 6-inch square cannot pass through a 6-inch round hole - the largest circle it fits
through is its own inscribed circle, exactly 6.000 inches, and its 8.485-inch diagonal stands
outside. This holds for every legal bag against every legal hole at every tolerance corner. So
every three-point score in cornhole is a deformation event, and a rigid-body simulation of the
sport cannot score at all.

## Sourced figures
- Deck 48 x 24 in; hole 6 in diameter with its centre 9 in from the top edge, centred side to
  side; back deck 12 in high (ACO 1.1 and ACL, in agreement).
- Front deck 2.8 in and deck angle 11 deg (ACL; the ACO gives 3-4 in and no angle).
- Boards 27 ft apart front edge to front edge, +/- 1/2 in (ACO 1.5 and ACL, identically). The
  widely repeated "33 feet" appears in neither rulebook.
- Bag 6 x 6 in, 16 oz, 1.3 in thick, plastic resin fill (ACO 1.3, ACL).
- Cornhole 3 points, woody 1 point, hanging bag 1 point, dead bag 0 (ACO 4.1, ACO 3.15,
  ACL Bag Values).
- Cancellation scoring; reach or exceed 21 at the end of a frame; no win-by-two; NO BUST RULE in
  either body (ACO 4.2; ACL "A player or team is not penalized for achieving a score over 21
  points").
- The scorer leads the next frame, and on a wash the previous leader KEEPS first pitch - it does
  not alternate (ACO 3.4; ACL Wash/Push).

## Reconstructed
Thirteen physics constants, listed in full in CREDITS.txt: the two faces' friction coefficients
and which one is faster, the bag's spread velocity and resting contact fraction, the
deformation-friction coupling, the bridging threshold at the hole, restitution, drag coefficient,
bag-on-bag response, the release point inside the 4 x 3 ft box, the release height, and the three
opponent levels. No RULE is reconstructed.

## Attribution
An independent reimplementation. Not affiliated with, endorsed by, or connected to the ACO or the
ACL. No text, art, code or data from either organisation is included.

## Files
- /CREDITS.txt - sources by article number, the two bodies' disagreements, and the complete
  reconstructed list
- /LICENSE.txt - MIT
- /manifest.webmanifest