Effects: Zig Zag Smooth points draw a continuous wave (#2343)

Smooth Zig Zag ran the ridge points through a Catmull-Rom spline. Its end tangents slant across the path, and where the ridges are taller than about twice their spacing the sharp-turn floor of turn_tangent lengthens the handles, so the result read as straight diagonals with rounded tips. Each peak and valley is now a smooth point whose handles run along the path, a third of the way to the neighbouring ridge, so every span follows a half cosine through the path.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/effects-parity.md

@@ -1,6 +1,6 @@
 # Effects parity
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-16 · **Change:** minor (G2: Effect › Sketch › Halftone Pattern; Photoshop filters 30/57, 27 remaining (22–38 h); Round Corners also rounds corners where a curve meets a line or another curve, with Live Corners' cut; straight corners unchanged; score unchanged; Revolve: automatic smooth shading and default-on Cap with continuous rims; wide shadows and glows at high zoom, #1706; stacked Transform effects, #1705; 3D on nonzero compound paths, #1724; pattern tiles redraw, #1723; scores unchanged; Roughen's Smooth turn-backs, #1643; Scribble per region, #1648; score unchanged; Warp Arc bends in the object's proportions, #1578; Zig Zag ridges evenly spaced, #1558; effect parameters checked, #1592; score unchanged; raster effects after a pattern, radial or freeform gradient fill export at their place and size, #1536; score unchanged; 3D and Materials on outlined type and other shapes of many small curves, #1481; Twist 0° to 360°, #1524; twisted walls keep their faces, #1525; score unchanged; 3D and Materials: Inflate takes Twist, Taper and Cap; score unchanged; 3D and Materials: Perspective as the documented 0°–160° angle; 3D and Materials: the documented light settings) · **Target:** Adobe Illustrator 2026 (30.x)
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-16 · **Change:** minor (Zig Zag's Smooth points make a continuous wave, #2343; G2: Effect › Sketch › Halftone Pattern; Photoshop filters 30/57, 27 remaining (22–38 h); Round Corners also rounds corners where a curve meets a line or another curve, with Live Corners' cut; straight corners unchanged; score unchanged; Revolve: automatic smooth shading and default-on Cap with continuous rims; wide shadows and glows at high zoom, #1706; stacked Transform effects, #1705; 3D on nonzero compound paths, #1724; pattern tiles redraw, #1723; scores unchanged; Roughen's Smooth turn-backs, #1643; Scribble per region, #1648; score unchanged; Warp Arc bends in the object's proportions, #1578; Zig Zag ridges evenly spaced, #1558; effect parameters checked, #1592; score unchanged; raster effects after a pattern, radial or freeform gradient fill export at their place and size, #1536; score unchanged; 3D and Materials on outlined type and other shapes of many small curves, #1481; Twist 0° to 360°, #1524; twisted walls keep their faces, #1525; score unchanged; 3D and Materials: Inflate takes Twist, Taper and Cap; score unchanged; 3D and Materials: Perspective as the documented 0°–160° angle; 3D and Materials: the documented light settings) · **Target:** Adobe Illustrator 2026 (30.x)
 
 Every entry of Illustrator's Effect menu, by its public feature name, against VectorCraft's effects catalogue
 (`effect_catalog()` in `crates/effects/src/lib.rs`) and the Effect menu built from it
@@ -22,7 +22,7 @@ Part of [target-app-parity.md](target-app-parity.md); open work is in [gaps.md](
 |---|---|---:|---|
 | Convert to Shape | Rectangle, Rounded Rectangle, Ellipse | 3/3 | — |
 | Crop Marks | Crop Marks | 1/1 | — |
-| Distort & Transform | Free Distort, Pucker & Bloat, Roughen, Transform, Tweak, Twist, Zig Zag | 7/7 | Free Distort's dialog has a handle on each corner of the object's bounds, moved by dragging or with the arrow keys; Transform's Transform Objects/Patterns and Scale Strokes & Effects options, invisible Reflect checkboxes (#885); Zig Zag's ridges are evenly spaced along each segment (#1558); Roughen with Smooth keeps turn-backs smooth instead of cusps that draw as spikes (#1646) |
+| Distort & Transform | Free Distort, Pucker & Bloat, Roughen, Transform, Tweak, Twist, Zig Zag | 7/7 | Free Distort's dialog has a handle on each corner of the object's bounds, moved by dragging or with the arrow keys; Transform's Transform Objects/Patterns and Scale Strokes & Effects options, invisible Reflect checkboxes (#885); Zig Zag's ridges are evenly spaced along each segment (#1558), and Smooth points make a continuous wave whose peaks and valleys have handles along the path (#2343); Roughen with Smooth keeps turn-backs smooth instead of cusps that draw as spikes (#1646) |
 | Path | Offset Path, Outline Object, Outline Stroke | 3/3 | With Use Preview Bounds on, Align, Distribute and the Transform panel still measure type that carries Outline Object by its layout box (preview bounds leave out effects) |
 | Pathfinder | Add, Intersect, Exclude, Subtract, Minus Back, Divide, Trim, Merge, Crop, Outline, Hard Mix, Soft Mix, Trap | 10/13 | Hard Mix, Soft Mix, Trap |
 | Rasterize | Rasterize… (as a live effect) | 0/1 | the live effect (Object › Rasterize exists) |
@@ -99,6 +99,7 @@ angular cut caps, exact visibility, 3D Classic, Turntable, 3D export) is 25–45
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-16 | minor | Zig Zag with Smooth points draws a continuous wave: every peak and valley is a smooth point with handles along the path, a third of the way to the next ridge, so each span follows a half cosine through the path instead of a straight diagonal with rounded tips, also at the ends of open paths and for ridges much taller than they are apart (#2343); score unchanged (estimated) |
 | 2026-10-16 | minor | G2: Effect › Sketch › Halftone Pattern (Size, Contrast, Pattern Type Circle, Dot or Line; black ink on white paper, Size in points at any Document Raster Effects resolution); measured Photoshop filters 30/57, 27 remaining (22–38 h). |
 | 2026-10-15 | minor | Round Corners rounds corners whose anchor carries a handle (where a curve meets a line, or two curves meet) with the round cut Live Corners uses (#1144), reaching `radius` along each side; before, they were left sharp. Corners between handle-less anchors are rounded as before; score unchanged (estimated) |
 | 2026-10-14 | minor | Revolve: automatic smooth vector shading, default-on Cap with continuous curved rims, and bounded seam joins; angular cut sides remain open. Scores and hour estimates unchanged at this rounding |