`plotters 0.3.3` updated from `font-kit 0.10.0` to `0.11.0`. This is an
internal dependency and ostensibly wouldn't be a breaking change, except
that `font-kit 0.11.0` added a dependency on `yeslogic-fontconfig-sys`
which has additional system dependency requirements. This had the effect
of breaking compilation in a non-breaking release.
However, `font-kit` is only required for `BitMapBackend`, which is not
part of our public API and is only used by some of the `halo2_gadgets`
tests. So we can avoid affecting our downstream users by disabling the
default-enabled features of `plotters`.
This feature flag is not part of the public API, but only for
conditionally rendering sub-circuit graphs. Renaming it stops the
feature from being enabled in the workspace when we only want to enable
the `dev-graph` feature flag of `halo2_proofs`, which _is_ part of its
public API.
These are all cases inside the ECC chip, where we are inherently
producing valid coordinate pairs as a result of the constraints being
implemented, but it is useful to be explicit about the contract being
asserted at each point we construct `EccPoint` or `NonIdentityEccPoint`.
- We were redundantly storing the `x_p` and `y_p` columns.
- `Config::add_incomplete` was redundantly copying.
Co-authored-by: therealyingtong <yingtong@z.cash>
Both variable-base scalar mul and Sinsemilla use double-and-add with
incomplete addition on a single row, but they do so in slightly
different ways. Some of these are intentional (needing to look up the
y-coordinate vs constrain it), while others are accidental (different
concrete signs in otherwise-identical constraints that make their ASTs
incompatible).
The new `DoubleAndAdd` helper struct extracts the logic that is common
to both implementations, specifically the helper definitions of `x_r`
and `Y_A`. In a future breaking change, we can refactor both gadgets to
share more of this logic, so we are defining the incomplete addition
logic in fewer places.
The new `EccInstructions` instructions, and the corresponding changes to
existing instructions, enable chips to choose when to witness or constrain
the scalars, and simplify scalar reuse (though reuse is not implemented
for `EccChip` yet).
`FixedPoint::mul` and `FixedPointShort::mul` now has the same API style
as `NonIdentityPoint::mul`.
Jack Grigg
Daira Hopwood
Kris Nuttycombe
ying tong
Taylor Hornby