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# yhtz - a yahtzee CLI game with 8 bytes of state
Inspired by [The Bitwise Gamedev Challenge](https://github.com/zesterer/the-bitwise-challenge).
Not sure if this *technically* counts since there aren't really "frames", but
the spirit of the challenge is there -- the game should be able to be picked up
at any point using the single 8 byte state struct.
## State layout
### Byte 1
* Roll count: 2 bits (high)
* "Top" section flags: 6 bits, one for each number, indicating whether we've played it yet
```
00 000000
roll ^^ ^^^^^^
count---|| ||||||
654321
```
### Byte 2
* "Top" rolling score: 7 bits (low)
* High bit is ignored
### Byte 3
* "Bottom" section flags: 7 bits (low), one for each category
* High bit is ignored
### Byte 4
* "Bottom" rolling score: 8 bits
### Bytes 5-6
* Dice: 5 total dice, each die has 3 bits, representing their current value
* High bit is ignored
```
x 000 000 000 000 000
D4. D3. D2. D1. D0.
```
### Bytes 7-8
* Seed: a 16-bit unsigned integer representing the seed for the random number generator.
Uses Dr. Lemire's [16-bit WyHash example](https://lemire.me/blog/2019/07/03/a-fast-16-bit-random-number-generator/).
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