qmk/quantum/debounce

Debounce algorithms belong in this folder. Here are a few ideas

1. Global vs Per-Key vs Per-Row

• Global - one timer for all keys. Any key change state affects global timer
• Per key - one timer per key
• Per row - one timer per row

2. Eager vs symmetric vs asymmetric

• Eager - any key change is reported immediately. All further inputs for DEBOUNCE ms are ignored.
• Symmetric - wait for no changes for DEBOUNCE ms before reporting change
• Asymmetric - wait for different times depending on key-down/key-up. E.g. Eager key-down, DEBOUNCE ms key up.

3. Timestamp vs cycles

• old old old code waits n cycles, decreasing count by one each matrix_scan
• newer code stores the millisecond the change occurred, and does subraction to figure out time elapsed.
• Timestamps are superior, i don't think cycles will ever be used again once upgraded.

The default algorithm is symmetric and global. Here are a few that could be implemented:

sym_g.c sym_pk.c sym_pr.c sym_pr_cycles.c eager_g.c eager_pk.c eager_pr.c //could be used in ergo-dox!