M5: opaque knockout fills draw once in hard-edge and supersampled raster export

A knockout element with one opaque Normal solid fill (a path or
compound, no mask, effects or isolation) is drawn once under
AntiAlias::None, including the internal hard-edge frame of Art
Optimized supersampled exports, instead of being erased and added back
through per-element backdrop layers. Analytical antialiasing keeps the
existing compositor and rounding.

Exact-pixel tests compare against the general knockout path for paths
and compound holes across precision, supersampling, translucent parents
and copied backdrops, and check that the backdrop rasters are skipped;
translucent fills keep their knockout compositing.

# Conflicts:
#	docs/roadmap.md
#	docs/target-app-parity.md

docs/roadmap.md

@@ -1,6 +1,6 @@
 # Roadmap: milestones and what's next
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-30 · **Change:** minor (File formats: `.ai`/EPS import fidelity from a user's file audit; scores unchanged) · **Target:** Adobe Illustrator 2026 (30.x)
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-30 · **Change:** minor (M5: supersampled exports avoid redundant opaque knockout layers; File formats: `.ai`/EPS import fidelity from a user's file audit; scores unchanged) · **Target:** Adobe Illustrator 2026 (30.x)
 
 ## Feature submission evidence
 
@@ -90,7 +90,7 @@ Checked 2026-10-10 from the code, tests and open issues; no workflow fails, so V
 | M2 | Drawing tools + smart guides | ✅ mostly done (Curvature point markers without direction handles (#1236, in part); Direct Selection segment click/Delete preserves neighboring edges, #1278; Flare, Reshape, Live Corners widget dragging and per-corner radii and kinds landed, on any path's corners; Shaper rough-shape recognition and orientation steps, the remaining Pen modifier nuances; Shaper Groups with editable sources and separate fill/stroke edits landed; custom ruler origin with drag preview, active-artboard reset, relative X/Y fields and native round-trip (#1212); construction widget/refinements pending) | 12–18 |
 | M4 | Files (native, SVG, PDF, raster, Export for Screens, clipboard interop) | ✅ done (M4.14–M4.98 on 2026-10-05): Save As/Save a Copy/Revert/templates, Data Recovery and background save, SVG import and export fidelity (units, text, symbols, filters, SVGZ, Preserve Editing, SVG Options), shared guarded PDF writer and windowed reader ([pdf-backend.md](pdf-backend.md)), PDF import (colours, layers, masks, editable text, security) and export (presets, marks, bleed, ICC and output intent, raster effects, subset fonts, PDF/X-1a, X-3 and X-4, PDF layers, overprint, page thumbnails, fast web view, PDF 1.3), Place and Links, Package, EPS and DXF in and out (EPS legacy mesh corners, vector opacity masks and raster page comparison verified; closed SPLINE flags round-trip and circular paths export as native CIRCLE/ARC, #1299), EMF/WMF, TIFF/BMP/Targa/PSD/GIF/PNG-8 export, Print and print presets, slices, Save for Web, TIFF in Export for Screens and Asset Export, clipboard flavours, File Info; AF.1–AF.4 add Affinity import (native layers, artboards, vectors, text and images from Affinity 1–3 files; the embedded preview only as a warned fallback; AF.4 expands current `.af` fixtures and every-board round-trip validation); EPS Save and Save As keep an opened EPS as EPS with its page frame and complete editable VectorCraft document (2026-10-26; G9 import fidelity unchanged). Left: DWG (use DXF), PSD placement as layers, overprint read back from PDF, Affinity export, polish | 3–6 (existing scope; Affinity export unestimated) |
 | M3 | Paint & appearance (swatches, color, gradient, stroke, appearance, transparency, styles) | ✅ done (M3.7–M3.98): swatches, groups, libraries, tints, Lab spots and Registration; Eyedropper styles highlighted text only (atomic transparency rejection); Eyedropper reads visible locked and outside-isolation sources (#1251); Color Picker, Color panel, Color Guide, Color Themes, Edit Colors and Recolor Artwork (screen-bounded Edit chip list, #3416); gradients that follow every transform, the annotator, linked stops, freeform gradients, focal points, gradients on strokes and Expand; visible strokes when paint is added to inherited None/zero-width art (#1253); stroke geometry, arrowheads, dashes fitted to corners, stroke on type, width profiles and the Width tool (Shift-double-click enables adjoining adjustment in Width Point Edit), Scale Strokes and preview bounds; Appearance targeting, container appearance, target circles, Expand Appearance; knockout, isolation, blend accuracy, CMYK blending, overprint, Attributes, masks and clipping, Flatten Transparency; graphic styles, links and libraries; CSS library export preserves fractional linear and radial gradient stop positions. Left: freeform and mixed spot/process gradients export as stops or process colours to SVG/PDF; confirm the Scale Strokes & Effects default | 4–8 |
-| M5 | Performance | 🟡 background render + caches + MT done; `vectorcraft-cli bench` and `vectorcraft-cli perf` (budget suite); file format v2 opens 3× faster (50k paths: 722 → 244 ms); raster effects (glows, shadows, blur, feather) no longer force the whole frame single-threaded (filtered offscreen per effect, verified equal to the single-threaded reference); Craquelure/Mosaic Tiles/Stained Glass distance searches optimized with pixel-invariance checks and the `texture_drag_perf` probe (#1257); effect-heavy demos need a clean-machine benchmark; dirty-region rendering, GPU backend spike pending | 15–25 |
+| M5 | Performance | 🟡 background render + caches + MT done; `vectorcraft-cli bench` and `vectorcraft-cli perf` (budget suite); opaque solid-fill knockout paths draw once in hard-edge/supersampled raster export, with analytical-AA compositing unchanged; file format v2 opens 3× faster (50k paths: 722 → 244 ms); raster effects (glows, shadows, blur, feather) no longer force the whole frame single-threaded (filtered offscreen per effect, verified equal to the single-threaded reference); Craquelure/Mosaic Tiles/Stained Glass distance searches optimized with pixel-invariance checks and the `texture_drag_perf` probe (#1257); effect-heavy demos need a clean-machine benchmark; dirty-region rendering, GPU backend spike pending | 15–25 |
 | M6 | Path operations (Pathfinder, Shape Builder, offset…) | ✅ mostly done (live compound shapes: Make, Alt-click a Shape Mode, member modes, Release, Expand (#4522); single-result Pathfinder names and SVG IDs retained (#1293); Divide open-cutting-path geometry, appearance and history verified (#1307; existing segment cap remains); Simplify preview/counts and rewritten-path component selection verified (#1272; the slider opens at the Auto-Simplify level; a Direct Selection part of a path simplifies on its own); Compound appearance and member fill-rule edits verified (#1197); Boolean precision on almost-horizontal edges fixed and the property tests made deterministic; Shape Builder gap detection, large-offset bug open); Shape Builder Gap Detection shares Live Paint’s spatial gap finder and temporary merge bridges (#2526); Custom is capped at 72 pt in the existing options dialog | 3–6 |
 | M7 | Type (point/area/path, editing, styles, OpenType, threading, glyphs) | 🟡 Hanging punctuation keeps its published amounts under Glyph Scaling, and Standard burasagari counts a hung line start as room; Fullwidth `！` / `？` keep an upright fallback in vertical type; Document-point character controls after object/group scaling (#1034; optional font-size preservation remains separate), Character/Paragraph Styles (explicit Auto-leading resets and local leading overrides), per-paragraph paragraph attributes, mixed paragraph alignment indication (headless regressions, full integration CI and visual review pass), Area Type Options (with Width/Height, Auto Size and Shrink Text to Fit; overflow reported to agents and vertical Align), type areas resized by their handles and reshaped with Direct Selection, threaded text, Fit Headline, Glyphs, OpenType panel, Find Font, installed system fonts in every font menu (fonts registered with Windows outside its font folders, the XDG and Flatpak host font folders on Linux, and fonts installed while the app runs, listed when it comes back to the front; searchable; the Character and Properties menus show each family's sample of the selected text, preview it live under the pointer or ↑/↓, show recently applied families first (#3515), filter by script and kind, list a family's styles, and star favourites; the Glyphs panel and Find Font's Replace With use the same menu without the live preview) and found by name on open/import (full-name aliases and Missing Fonts searches verified, #1258; Windows font-service QA pending), variable fonts' named instances as styles, CJK names in the UI, input methods (marked text in place, candidate window at the caret; Japanese IME), Text Wrap (offset, invert, both sides of an object; follows edits), Type on a Path effects and Options with draggable start/centre/end brackets (slide, flip), tab stops + Tabs panel (Above Text floats it over the selected text, its ruler at the canvas zoom so stops line up with the columns, #729), inline symbols in text (beyond parity), Hebrew/Arabic bidirectional text, Paragraph Direction, Every-line/Single-line Composer per object (ragged text too) done; tab leaders, spell check, vertical type pending | 45–60 |
 | M7 | Type (point/area/path, editing, styles, OpenType, threading, glyphs) | 🟡 Fullwidth `！` / `？` keep an upright fallback in vertical type; Hyphenation… and Justification… per paragraph (#2310, #2755), Auto Leading also driving the Character panel's Leading, the Alt+↑/↓ leading nudge and Fill with Placeholder Text; Document-point character controls after object/group scaling (#1034; optional font-size preservation remains separate), Character/Paragraph Styles (explicit Auto-leading resets and local leading overrides), per-paragraph paragraph attributes, mixed paragraph alignment indication (headless regressions, full integration CI and visual review pass), Area Type Options (with Width/Height, Auto Size and Shrink Text to Fit; overflow reported to agents and vertical Align), type areas resized by their handles and reshaped with Direct Selection, threaded text, Fit Headline, Glyphs, OpenType panel, Find Font, installed system fonts in every font menu (fonts registered with Windows outside its font folders, the XDG and Flatpak host font folders on Linux, and fonts installed while the app runs, listed when it comes back to the front; searchable; the Character and Properties menus show each family's sample of the selected text, preview it live under the pointer or ↑/↓, filter by script and kind, list a family's styles, and star favourites; the Glyphs panel and Find Font's Replace With use the same menu without the live preview) and found by name on open/import (full-name aliases and Missing Fonts searches verified, #1258; Windows font-service QA pending), variable fonts' named instances as styles, CJK names in the UI, input methods (marked text in place, candidate window at the caret; Japanese IME), Text Wrap (offset, invert, both sides of an object; follows edits), Type on a Path effects and Options with draggable start/centre/end brackets (slide, flip), tab stops + Tabs panel (Above Text floats it over the selected text, its ruler at the canvas zoom so stops line up with the columns, #729), inline symbols in text (beyond parity), Hebrew/Arabic bidirectional text, Paragraph Direction, Every-line/Single-line Composer per object (ragged text too) done; tab leaders, spell check, vertical type pending | 45–60 |
@@ -141,6 +141,7 @@ separate. Scores and hours unchanged. [Behavior and command details](development
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-30 | patch | M5: opaque solid-fill knockout paths avoid redundant erase/add layers in hard-edge frames and supersampled raster export; exact-pixel regression coverage retains analytical-AA rounding and translucent knockout behavior; scores and estimates unchanged |
 | 2026-10-30 | minor | M4: G9: `.ai`/EPS editing data: a blend takes the transparency (opacity, blend mode, knockout) in its state block after its record, so its steps knock each other out as the page draws them; a user's file comes in 0.6% from its page instead of 1.3%. Scores and estimates unchanged. |
 | 2026-10-30 | minor | M4: File formats: `.ai`/EPS editing-data fidelity from an audit of a user's files: All Caps and Small Caps (#4708); placed files at their box's corner, kept where they draw closer to the page (#4664, #4723, #4742); pages cropped to the art, with `UserUnit` (#4658, #4727); gradient mesh corners with handle weights of 0 and the state written after a mesh (#4738, #4744, #4748); type on a path spaced as the file lays it out (#4743); synthetic regressions in `crates/eps`; scores and estimates unchanged. |
 | 2026-10-29 | minor | M6: Pathfinder: live compound shapes (#4522): the panel menu's Make, Release and Expand Compound Shape, Alt-clicking a Shape Mode, a selected member's Shape Mode and the Expand button act; scores unchanged |