Extension osnap now offers a ray off every polyline vertex, not just the
first and last, and snaps to where two segments' extension lines would
cross. That crossing is emitted as an Intersection so it outranks the
per-segment extension feet on their own lines. When it wins, both
contributing extensions are re-detected — off-ray distance measured in
screen space so the tolerance holds at UTM coordinates — and the overlay
draws a dashed guide from each endpoint through the crossing, so both
extension paths remain visible instead of vanishing when caught.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The Extension object snap worked but drew no tracking path, so it was
easy to miss — users had to keep the cursor exactly on the invisible
extension line without any visual cue.
When an Extension snap is active, draw a dashed guide line from the
endpoint it extends from, through the snap point and a little beyond,
and orient the three-dot marker along that direction. SnapResult carries
the endpoint screen position (filled once the winning snap is known);
the overlay renders the guide.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
- Delete src/modules/draw/modify/extend.rs (a 1-line placeholder with no
tool()/logic; `extend::` was referenced nowhere) and its `mod extend;`.
- Flatten single-file module dirs to the modern flat style:
src/command/mod.rs -> src/command.rs, src/snap/mod.rs -> src/snap.rs.
Parent `mod command;`/`mod snap;` are unchanged.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
