Merge pull request #6492 from dotCooCoo/fix/reshape-stretches-whole-path

Reshape: a drag stretches an open path from the dragged point to its two ends

docs/mcp.md

@@ -3627,6 +3627,22 @@ the canvas (coordinates out of range)".
 is not a whole number of 0 or more, such as 1.5, -1 or "1" ("missing integer `subpath`"); `path.split` refuses such
 an `anchor` or `segment` in the same way. The document does not change and no undo step is recorded.
 
+`path.reshape {id, x, y, dx, dy, tol?, radius?}` (a Reshape tool drag) grabs the path at `x`, `y`, adding an anchor
+there unless one lies within `tol` (3 by default), and moves that point by `dx`, `dy`.
+[Adjust path segments](https://helpx.adobe.com/illustrator/desktop/draw-shapes-and-paths/modify-paths/adjust-path-segments.html)
+has the Reshape tool stretch part of a path from the dragged point without losing the path's general form. How far
+the stretch reaches and the share of the drag each point takes are VectorCraft's own rule. An open path stretches from
+the grabbed point to its two ends: the two end anchors stay in place, and each anchor between an end and the grabbed
+point takes `u² (3 - 2u)` of the drag, where `u` is its distance from that end along the path's control polygon
+(anchor, out handle, the next in handle, the next anchor) divided by the grabbed point's distance from that end. A
+handle takes the share on the tangent line of that curve at its anchor, so the handles of a smooth anchor stay in line
+with it; a handle that is long beside the distance from the end to the grabbed point takes a share below 0 or above 1,
+and moves against the drag or farther than the grabbed point. On a closed path, or when `radius` is given, the anchors
+within `radius` of the grabbed point along the path follow with a smooth falloff and the others stay; `radius`
+defaults to half the diagonal of the subpath's bounding box, and a negative `radius` is refused ("`radius` must be 0
+or more"). A drag of no length on an anchor (`dx` and `dy` 0 or left out) leaves the path as it is and records no undo
+step.
+
 These commands refuse a string or another value that is not a number with `` `dy` must be a number, not "10" ``,
 naming the key; the document does not change and no undo step is recorded: `t`, `dx` and `dy` in
 `path.reshapeSegment` and `object.blend.spine.reshapeSegment`; `x`, `y` and `t` in `path.curvatureEdit`; `x` and `y`

docs/target-app-parity.md

@@ -929,6 +929,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
     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).
+    A Reshape drag stretches part of a path from the dragged point without losing the path's general form, as [Adjust path segments](https://helpx.adobe.com/illustrator/desktop/draw-shapes-and-paths/modify-paths/adjust-path-segments.html) has it. On an open path the stretch reaches both ends: the end anchors stay in place, each anchor between moves less the nearer it lies to an end, and the handles of a smooth anchor stay in line (`path.reshape`; the reach and the shares are VectorCraft's own rule, in `docs/mcp.md`). On a closed path the anchors within half the diagonal of the subpath's bounding box, measured along the path, follow the dragged point. Clicks do not set focal points.
     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).
     Transform Each opens on the scale, move, rotate, reflect, Random, reference point, Transform Objects and Preview it was last confirmed with (kept with the UI state; Copy never is), and its Copy button, left of Cancel, transforms a copy of each object as the [Scale multiple objects](https://helpx.adobe.com/illustrator/desktop/manage-objects/reshape-transform-objects/scale-multiple-objects.html) help page has it; the Copy checkbox is gone (#1732; the remembered values follow a maintainer comment on the issue, not the help page). Its Scale section has the Relative and Absolute radio buttons the same page describes: percentages of each object's size, or the width and height it becomes (`object.transformEach` `relative`, which Transform Again repeats); Absolute measures each object's own box, and the scales act along its axes about that box's reference point, so a turned shape keeps its shape and objects of different sizes come out alike; the fields show the width and height the selected objects share and read "Mixed" when they differ or a side is 0 (a line's), each object measured by its own box, rotated with it, as the Transform panel and the Control bar show it (sizes they show alike count as the same), and a size typed into them sets every object to it (a side left Mixed keeps its size), our choices where the page leaves them open; a live Repeat scales its spacing by the geometric mean of the two factors, so its Absolute size is approximate. The link beside the two scales keeps them in proportion, as the shape dialogs' Width and Height link does (`__constrain`, kept with the dialog's values; where it sits is our choice, the public pages don't establish it). The panel lists Scale, Move and Rotate, then the Options in two columns (Transform Objects, Transform Patterns, Scale Strokes & Effects, Scale Corners; Reflect X, Reflect Y, Random), the Reference Point, and Preview at the left of the button row, level with Copy, Cancel and OK.
     Transform Again uses the Copy, Transform Patterns, Scale Strokes & Effects and Scale Corners choices of the transform it repeats; after a bounding-box handle drag on area type, it resizes the type area again and the type keeps its size (`object.transformAgain`). With anchors selected with Direct Selection, Move, Rotate, Scale, Reflect, Shear and Transform Again (the commands, their dialogs and the four tools' drags) transform only those anchors, their handles with them, about the centre of the box around them unless a point was clicked; a copy still copies the whole object (#1408; behaviour reference: [adjust path segments](https://helpx.adobe.com/illustrator/using/adjust-path-segments.html); the default reference point and the copy are our choices). The Move, Rotate, Scale, Reflect and Shear dialogs have a Preview checkbox, off when they open: while it is on the canvas follows the values, Cancel rolls it back and OK is still one undo step; Up/Down step the Rotate and Shear angles and the Scale percentages by 1, Shift by 10 (#1412). The five dialogs and Transform Each have Transform Objects beside Transform Patterns: off, the art stays and only its pattern tiles transform (`objects` on the transform commands), and Transform Again repeats the choice (#1448; behaviour reference: [scale objects](https://helpx.adobe.com/illustrator/desktop/manage-objects/reshape-transform-objects/scale-objects.html); the checkboxes are always enabled and the Scale page's pair is applied to all of them, our choices). Reflect's axis is Horizontal, Vertical or an angle (#1460; [reflect objects along an axis](https://helpx.adobe.com/illustrator/desktop/manage-objects/arrange-objects/reflect-objects-along-an-axis.html)).