# Changelog

Notable changes on `feature/parametric-constraint-system` since each push to
GitHub. Newest entries first. "Unreleased" covers local changes not yet
pushed.

## Unreleased (since `eb96e8b6`)

- **Fix:** a dimensional constraint's value prompt (e.g. `DCONSTRAINT`'s
  "Specify distance:") rejected a named parameter typed in its own
  lowercase name — the command line uppercases typed text before it
  reaches the parser, so `r` became `R` and no longer matched the
  parameter table's case-sensitive lookup. `parse_driving_value` now
  matches parameter names case-insensitively and resolves to the
  parameter's canonical name.
  ([value.rs](src/modules/draw/constrain/value.rs))
- **Feature:** Named Parameters panel gains a "Used by" column showing
  which constraints (kind + entity handles) currently reference each
  parameter, with a hover tooltip listing the full per-constraint entity
  breakdown when more than a couple of constraints use it. Backed by a new
  `Scene::parameter_usage(name)` query that searches every sketch scope
  (model space and blocks) and deduplicates an entity referenced by more
  than one of a constraint's point markers.
  ([named_parameters.rs](src/ui/window/named_parameters.rs),
  [sketch_constraints.rs](src/scene/sketch_constraints.rs))
- Named Parameters modal widened (620 → 820) to fit the new column.
  ([modal.rs](src/app/view/modal.rs))
- **Feature:** constraint-solver support extended well beyond Line/Circle,
  closing most of the gap with FreeCAD's Sketcher (grounded against real
  ObjectARX headers so DWG-native persistence stays honest about what
  AutoCAD itself can represent):
  - Arcs are now full constraint participants: center/radius (Concentric,
    Tangent, Equal, CenterPoint, Radius, Diameter, Fixed, Normal) via the
    same solver representation a Circle uses, *and* actual endpoints
    (Coincident/PointOnCurve/Midpoint/EqualDistance/Symmetric on an arc's
    real start/end point, marker 0/1) — kept numerically consistent with
    center/radius/angle by "arc rules" constraints added for every
    registered arc, reusing an already-ported-but-unused `ocs_gcs`
    primitive (`CurveValue`) rather than new low-level math.
  - New dimensional kinds: `Diameter`, `DistanceX`, `DistanceY`,
    `ArcLength` — reusing existing DWG classes (Diameter/DistanceX/Y ride
    the same `ACRADIUSDIAMETERCONSTRAINT`/`ACDISTANCECONSTRAINT` objects
    Radius/Distance already use, with a different mode/direction byte,
    matching how AutoCAD itself represents them). `ArcLength` has no DWG
    equivalent at all (confirmed against ObjectARX's own headers) and is
    XRecord-only by design, not omission.
  - New geometric kind: `Normal` (a line perpendicular to a circle/arc's
    tangent), matching AutoCAD's real `kNormal` constraint type.
  - New entity: `Ellipse` (center/Concentric/CenterPoint/Fixed only —
    major/minor axis dimensional constraints and `PointOnEllipse`-based
    Coincident/Tangent remain a follow-up). DWG-native persistence for
    ellipse-referencing constraints is deliberately not implemented yet —
    `acadrust`'s `Ellipse`/`BoundedEllipse` node variants have a different
    field shape than the geometry-dependency role Circle/Arc play, and
    guessing the semantics risked writing a plausible-but-wrong object
    graph, so it degrades to XRecord-only instead.
  ([sketch_solve.rs](src/scene/sketch_solve.rs),
  [sketch_constraints.rs](src/scene/sketch_constraints.rs),
  [dwg_native_constraints.rs](src/scene/dwg_native_constraints.rs),
  [value.rs](src/modules/draw/constrain/value.rs))