add critical hits

[andrewgazelka]

add critical hits

related #538

[andrewgazelka]

we want PvP to feel like normal mc :)

[maxomatic458]

you can probably use some parts of this here as reference:
https://github.com/maxomatic458/valence-extra/blob/master/crates/combat/src/lib.rs

^ that includes logic for the old and new combat system as well as support for combat relevant enchantments

EDIT:
for critical hits you would need to check if the player is falling, i solved that by just checking if the player is on a block every tick.
If the player is not, and the last grounded y level is higher then the player is falling

[Tebarem]

Great! Thank you. We already track the previous tick position so I was going to just check if the y delta is negative. Gut stuck on arrows tho :)

[maxomatic458]

Great! Thank you. We already track the previous tick position so I was going to just check if the y delta is negative. Gut stuck on arrows tho :)

If you want to implement fall damage as well you would also need to keep track of some more information
https://github.com/maxomatic458/valence-extra/blob/7eba80fe928ba04114c36bdde567bdcaa6b846ea/crates/fall_damage/src/lib.rs#L4-L11