Knife: a straight cut's ends snap to the anchors and paths Smart Guides snap to

Squashed from #5044 onto main.
2026-11-01 05:37:23 -06:00 · 2026-11-01 09:24:13 +07:00
parent c38607a5ae
commit b253356b4d
6 changed files with 216 additions and 26 deletions
@@ -705,6 +705,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
  - **Cutting:** Eraser, Scissors, Knife, Mirror & Cut, Line Cut and Rectangle Cut (real geometry, compound paths keep their holes).
    While Alt is held, the Scissors tool works as the Add Anchor Point tool ([Default keyboard shortcuts](https://web.archive.org/web/20260726060015/https://helpx.adobe.com/illustrator/using/default-keyboard-shortcuts.html)): a click on a segment adds an anchor point without cutting (`path.insertAnchor`), and the pointer shows the Add Anchor Point cursor. When Alt is let go, a click cuts again.
    Alt-drag with the Knife cuts in a straight line, and Shift+Alt-drag cuts at 45° or 90°, as [Cut objects using the Knife and Scissors tools](https://web.archive.org/web/20260926095638/https://helpx.adobe.com/illustrator/desktop/manage-objects/edit-objects/cut-objects.html) and [Default keyboard shortcuts](https://web.archive.org/web/20260726060015/https://helpx.adobe.com/illustrator/using/default-keyboard-shortcuts.html) describe. Alt counts only when held at the press; the dashed line runs from the press point to the pointer, stays straight after Alt is let go, and release sends `path.knife` with those two points. Alt pressed after the press leaves the cut freehand. Shift+Alt keeps the endpoint at 45° steps from the horizontal and vertical, whatever the Constrain Angle.
+    With Smart Guides on, a straight Knife cut snaps to anchor points and paths: [Cut objects using the Knife and Scissors tools](https://helpx.adobe.com/illustrator/desktop/manage-objects/edit-objects/cut-objects.html) describes the Knife snapping to anchor points and paths while Smart Guides are on. Its ends snap as the ends of the Pencil's straight line do, to anchor points and path segments of art that is shown: the press, and the release of an Alt-drag. Shift+Alt steps 45° from the snapped press, and its release stays on that step. With Smart Guides off, or with Snap to Pixel or Snap to Grid on, the cut is not snapped. The dashed line and `path.knife` use the snapped points.
    Eraser Tool Options has Angle and Roundness besides Size, as [Erase paths using the Eraser tool](https://helpx.adobe.com/illustrator/desktop/draw-shapes-and-paths/modify-paths/erase-paths-using-eraser-tool.html) describes: the Eraser's tip is an ellipse Size across, its long axis at Angle and its short axis Roundness percent of the long one, and a drag with a tip that is not round shows the outline of the area it erases (`path.eraseRegion` `angle` and `roundness`).
  - **Transform:** Rotate, Reflect, Scale, Shear (click or Alt-click snaps the reference point to anchors and centres; Alt-click opens the tool's dialog, and a drag with Alt down at the release, from the press or pressed mid-drag, transforms a copy), Reshape, Free Transform (free and perspective distort and shear, switched by the keys held during a handle drag).
    Align, Distribute, Distribute Spacing, Reflect and Shear return an error for any `horizontal`, `vertical`, `to`, `axis`, `bounds` or `spacing` value they don't take, listing the choices, and Align returns one when a call gives neither `horizontal` nor `vertical`; nothing moves and no undo step is recorded. Align and Distribute act on the anchor points selected with Direct Selection: the points of one path align to each other, not to the artboard, and Distribute spaces them (#1641, fixes #1636; aligning to a key anchor is still missing).