This adds the `Pen` tool to Grease Pencil Edit Mode.
With the pen tool you can:
- Extrude points by `Left Click`.
- Move the handles by dragging the mouse.
- Snap handles to 45 degree increments with `Shift`.
- Cycle through the handle types by `Double Clicking`.
- Add new point on segments by `Ctrl Clicking`.
- Remove existing point by `Ctrl Clicking`.
- Close a curve by clicking on one end while having the other selected.
- Move existing segment by clicking and dragging on the edge.
- Move points by clicking and dragging the mouse.
Some changes have been made compared to the legacy
curve object's pen tool:
- `Angle locking` with `Alt` was replaced with `Angle Snapping`
using `Shift`. This was done to match the behavior of Grease Pencil
primitive tools.
- `Move Entire Point` was changed from the `Space` key to `Alt`. This
was done because some laptops can't move the mouse while
`Space` is held.
- `Link Handles` and `Free Align Toggle` were not implemented.
- `Toggle Vector` and `Close Spline Method` were removed.
- `Close Spline` was removed and set to always be true.
- `Extrude Handle` type was removed as a option and was replaced
by the `shift` modifier key when clicking.
- Newly created points are placed on the drawing plane, instead of
the view plane.
When a new curve is created, the material will be the active material
and the radius will be set from the `radius` property.
Note: This tool is added to edit mode because it uses handle selection
and bézier overlays which currently don't exist in draw mode.
A future PR will implement a draw mode version.
Pull Request: https://projects.blender.org/blender/blender/pulls/142646
a767671c56