Plug-ins: filters read and set effects and stroke styles (G17)

A filter could reshape and repaint objects, but not set the stroke's
join, cap or miter limit, nor the effects an object's appearance holds.
A tool that prepares objects for a live effect (a sheet of samples,
each with the effect at its own settings) had to leave the user to
apply the effect to each object by hand.

- Each input stroke has its join, cap and miterLimit beside its paint
  and width (live effects get the same, through the shared encoder),
  and each object its own effect records, {id, params, visible}.
- An output stroke may set them (miter limit clamped to 1-500), and an
  output object's "effects" replaces its own effects.
- The host admits each record as effect.apply does: an effect that
  effect.list lists or an installed live-effect plug-in, parameters it
  takes (filled in to their defaults; a plug-in's checked against its
  manifest), one 3D effect that fits the object (its fills' and
  strokes' own effects counted), and the texture of an effect with
  Load Texture (Glass, Texturizer) as the effect stores it, never a
  file to read. A record the object already had stays as
  it is, so a filter that hands its input back changes nothing. One
  refused record refuses the whole output and the document stays as
  it was.

The plug-ins crate checks the records' form; which effects exist is the
engine's to say (objects::AdmitEffects, engine plugin::admit_effects).
effects::validate_three_d is the one check of whether a 3D effect fits
an object, for effect.apply, effect.setParams and the filters.

A path handed back as it was now stays the live shape it was: write()
dropped a live rectangle's or ellipse's parameters whenever the output
held a path, changed or not, so a filter that returned its input
turned a live rectangle into a plain path.

objects/tests.rs checks the round trip, stroke styles on existing and
new strokes, the host's refusal, the bad forms refused, and a live
rectangle handed back unchanged (a plain path before the fix);
tests_plugins.rs runs filters that set a built-in and a plug-in effect,
an echo that changes nothing, and six refused outputs.
CRAFT_PLUGIN_FRAME_WASM=<folder> saves a test filter to try in the app.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01HhvnnnD5fTFupK8WWq35un

docs/gaps.md

@@ -1,6 +1,6 @@
 # Gaps
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-21 · **Change:** minor (3D: original Standard, Diffuse, Top Left and Right lighting presets; command access, effective-setting recognition and preview/history; scores and estimates unchanged; G1: one selected clip group's Properties panel has Edit Clipping Path and Edit Contents at its top; the selection tools take a clipping path on its outline, over the art it clips; Polygon and Star exact-size placement remembers the chosen count for later drags and dialog openings; Cancel preserves the previous count; Live trace result bounds and selection highlights exclude the retained bitmap except in source-image views; live-effect plug-ins given their object's fills and strokes and the item they sit on, G17; plug-in parameters: labels, units, groups, help and conditions in their dialogs, text and number-list parameters, up to 256 of them, G17; exporter plug-ins: plug-in file formats in Export As and document.export, G17; G2: Effect › Artistic › Smudge Stick, Sponge and Watercolor; Sketch › Bas Relief, Charcoal, Photocopy and Stamp, #2533; Photoshop filters 45/57, 12 remaining (8–14 h); on-canvas Mirror Repeat axis, #2877; G12: Background Export progress dialog with Cancel, #2564; status-readout sample widths cached by language, document unit and pixels per point; status messages and readouts use stable responsive allocations sized for localized labels and ordinary coordinates; cached canvas dimensions match the renderer limit before cache-key creation, view construction and worker submission; cached canvas reprojection preserves scale during resize, rotation and DPI changes; on-canvas Mirror Repeat axis, #2877; G12: Background Export progress dialog with Cancel, #2564; 3D lighting: one to ten colored lights, smooth colored Inflate, legacy white-light appearance preserved; surface batching and restored seam minimum; scores and estimates unchanged; Blend spine Anchor Point conversions, selection/stacking priority and Shift regression coverage (#2544); scores and hours unchanged; transparency grid visibility saved in native documents, #1968; G6: MCP cancellation, progress notifications and busy answers during long exports, #2165, #2171, #2172; EPS editing data: legacy mesh corners, vector opacity masks and compound member paint retained; raster page comparison filters minification without relaxing limits; scores and hours unchanged; correction: quick Image Trace presets leave the panel as it was, the Image Trace button opens it; batch exporting, #1935; G2: Effect › Sketch › Halftone Pattern; Photoshop filters 45/57, 12 remaining (8–14 h); G5: Symbol Options Export Type (Graphic / Movie Clip); G1: Smart Guides line extension, #2120; G16: Brazilian Portuguese catalog complete under the tests, #1914; Localization 71% → 74%, hours 55–90 → 50–85; G6: image variables landed, estimate 8–14 → 6–12 h; Warp Options controls verified by focused checks and original-image review; estimates unchanged; existing-guide Escape cancellation validated 2026-10-14; scores and hours unchanged; open-path anchor Delete keeps surviving runs separate; estimates unchanged; Artboard tab-switch follow-up historically validated on `a0671777`; scores and hours unchanged; Artboard clean active-tab close/Delete follow-up validated 2026-10-15; G13: Object › Intertwine landed, #1763; no entry closed, estimates unchanged; MCP `add_text` exposes the existing `vertical` option for point, area and path type; horizontal remains the default; scores and hours unchanged; Vertical fullwidth question and exclamation marks keep their nominal glyph upright when the font has no vertical alternate; scores and hours unchanged.; G1: Curvature curve geometry, #1236 in part; Width-point finite-arithmetic follow-up validated; scores and hours unchanged; Image Trace adjustment discovery; G9: legacy `.ai` of version 7 saved with type as text and hidden objects kept, legacy type read, #868; estimate unchanged; Revolve: automatic smooth shading and default-on Cap with continuous rims; later 2026-10-14: G8 untrusted files, #1852, #1862–#1873; G11 anchor X/Y/W/H, #1824, Snap to Grid over Snap to Pixel, #1816, redo during a drag, #1719, Dim Images, #1683, failed-save dialog, #1685; gaps noted for reporters: G1 Warp Options for Effect › Warp, #1760, Color Picker Tab order, #1692, key anchor, #1636; G7 custom toolbars, #1759, workspace panel widths, #1753; G11 Shape Builder gaps between closed shapes, #1691, interior anchor delete; G13 Intertwine, #1763, gradient mesh from an image, #1676, Image Trace radial gradients, #1849; G12 duplicated line removed; no entry closed, estimates unchanged; verified PngSuite downloads, #1729; synthetic control-input budgets, #1709; 2026-10-14 fixes: G11 anchor Align and Distribute, #1636, Delete and selection, #1674, #1666, #1743, #1686, Roughen and Scribble, #1643, #1648; G8 file and input hardening, #1776–#1783, #1786, #1807; G10 Wayland cursors aLine truncated
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-21 · **Change:** minor (filter plug-ins read and set effect records and stroke joins, caps and miter limits, G17; 3D: original Standard, Diffuse, Top Left and Right lighting presets; command access, effective-setting recognition and preview/history; scores and estimates unchanged; G1: one selected clip group's Properties panel has Edit Clipping Path and Edit Contents at its top; the selection tools take a clipping path on its outline, over the art it clips; Polygon and Star exact-size placement remembers the chosen count for later drags and dialog openings; Cancel preserves the previous count; Live trace result bounds and selection highlights exclude the retained bitmap except in source-image views; live-effect plug-ins given their object's fills and strokes and the item they sit on, G17; plug-in parameters: labels, units, groups, help and conditions in their dialogs, text and number-list parameters, up to 256 of them, G17; exporter plug-ins: plug-in file formats in Export As and document.export, G17; G2: Effect › Artistic › Smudge Stick, Sponge and Watercolor; Sketch › Bas Relief, Charcoal, Photocopy and Stamp, #2533; Photoshop filters 45/57, 12 remaining (8–14 h); on-canvas Mirror Repeat axis, #2877; G12: Background Export progress dialog with Cancel, #2564; status-readout sample widths cached by language, document unit and pixels per point; status messages and readouts use stable responsive allocations sized for localized labels and ordinary coordinates; cached canvas dimensions match the renderer limit before cache-key creation, view construction and worker submission; cached canvas reprojection preserves scale during resize, rotation and DPI changes; on-canvas Mirror Repeat axis, #2877; G12: Background Export progress dialog with Cancel, #2564; 3D lighting: one to ten colored lights, smooth colored Inflate, legacy white-light appearance preserved; surface batching and restored seam minimum; scores and estimates unchanged; Blend spine Anchor Point conversions, selection/stacking priority and Shift regression coverage (#2544); scores and hours unchanged; transparency grid visibility saved in native documents, #1968; G6: MCP cancellation, progress notifications and busy answers during long exports, #2165, #2171, #2172; EPS editing data: legacy mesh corners, vector opacity masks and compound member paint retained; raster page comparison filters minification without relaxing limits; scores and hours unchanged; correction: quick Image Trace presets leave the panel as it was, the Image Trace button opens it; batch exporting, #1935; G2: Effect › Sketch › Halftone Pattern; Photoshop filters 45/57, 12 remaining (8–14 h); G5: Symbol Options Export Type (Graphic / Movie Clip); G1: Smart Guides line extension, #2120; G16: Brazilian Portuguese catalog complete under the tests, #1914; Localization 71% → 74%, hours 55–90 → 50–85; G6: image variables landed, estimate 8–14 → 6–12 h; Warp Options controls verified by focused checks and original-image review; estimates unchanged; existing-guide Escape cancellation validated 2026-10-14; scores and hours unchanged; open-path anchor Delete keeps surviving runs separate; estimates unchanged; Artboard tab-switch follow-up historically validated on `a0671777`; scores and hours unchanged; Artboard clean active-tab close/Delete follow-up validated 2026-10-15; G13: Object › Intertwine landed, #1763; no entry closed, estimates unchanged; MCP `add_text` exposes the existing `vertical` option for point, area and path type; horizontal remains the default; scores and hours unchanged; Vertical fullwidth question and exclamation marks keep their nominal glyph upright when the font has no vertical alternate; scores and hours unchanged.; G1: Curvature curve geometry, #1236 in part; Width-point finite-arithmetic follow-up validated; scores and hours unchanged; Image Trace adjustment discovery; G9: legacy `.ai` of version 7 saved with type as text and hidden objects kept, legacy type read, #868; estimate unchanged; Revolve: automatic smooth shading and default-on Cap with continuous rims; later 2026-10-14: G8 untrusted files, #1852, #1862–#1873; G11 anchor X/Y/W/H, #1824, Snap to Grid over Snap to Pixel, #1816, redo during a drag, #1719, Dim Images, #1683, failed-save dialog, #1685; gaps noted for reporters: G1 Warp Options for Effect › Warp, #1760, Color Picker Tab order, #1692, key anchor, #1636; G7 custom toolbars, #1759, workspace panel widths, #1753; G11 Shape Builder gaps between closed shapes, #1691, interior anchor delete; G13 Intertwine, #1763, gradient mesh from an image, #1676, Image Trace radial gradients, #1849; G12 duplicated line removed; no entry closed, estimates unchanged; verified PngSuite downloads, #1729; synthetic control-input budgets, #1709; 2026-10-14 fixes: G11 anchor Align and Distribute, #1636, Delete and selection, #1674, #1666, #1743, #1686, Roughen and Scribble, #16Line truncated
 
 Every known shortfall against Illustrator, one entry each, **ranked by how much it stops a professional from
 switching**. This is the work list: unless you were given a task, pick the highest-ranked gap you can make
@@ -355,6 +355,10 @@ from G14 and the budget run of G15: **~170–270 h** one agent, ~50–80 h wall
   regressions.
 - **Done:** a live effect is given its object's fills and strokes, read only, as a filter is, and `_context.item`
   says which fill or stroke it sits on; a change of paint runs it again. Engine and unit regressions.
+- **Done:** a filter is given its objects' effect records and their strokes' join, cap and miter limit, and may
+  return both: the records are admitted as `effect.apply` admits them (one refused refuses the output), so a tool can
+  set up objects for a live effect in one step. A path a filter hands back unchanged stays a live shape. Engine and
+  unit regressions.
 - **Estimate:** 20–45 h for the APIs; the ecosystem itself isn't agent work.
 
 ## G18 Generative AI features
@@ -380,6 +384,7 @@ from G14 and the budget run of G15: **~170–270 h** one agent, ~50–80 h wall
 | 2026-10-20 | minor | G1: for the selection tools, a press within the selection tolerance of a clipping path's outline (a clip group's, or a layer's clipping mask) hits the clipping path before the art it clips, so Direct Selection takes its segments and the Selection tool the clip group even where the art lies over the mask's edge; Select Behind lists the same; the eyedropper and the tools that act on what is drawn are unchanged. Doc and tool regression tests. No entry closed, estimates unchanged. |
 | 2026-10-20 | minor | Polygon and Star exact-size placement remembers the chosen count for later drags and dialog openings; Cancel preserves the previous count; existing opening gestures retained; scores and hours unchanged. |
 | 2026-10-20 | minor | Live trace result bounds and selection highlights exclude the retained bitmap except in source-image views; scores and hours unchanged. |
+| 2026-10-19 | minor | G17: filter plug-ins read and set their objects' effect records (admitted as `effect.apply` admits them) and strokes' joins, caps and miter limits; a path handed back unchanged stays a live shape; engine and unit regressions. No entry closed, estimates unchanged. |
 | 2026-10-19 | minor | G17: live-effect plug-ins are given their object's fills and strokes, read only, and the item they sit on; engine and unit regressions. No entry closed, estimates unchanged. |
 | 2026-10-19 | minor | G17: plug-in parameters with labels, units, help, groups and conditions (`visibleWhen`), `string` and `numberList` types, up to 256 per plug-in; manifest and kittest dialog regressions. No entry closed, estimates unchanged. |
 | 2026-10-19 | minor | G17: exporter plug-ins, plug-in file formats that Export As and `document.export` write; engine, ABI and headless Export As regressions. No entry closed, estimates unchanged. |