Record native preview benchmarks and review evidence

ATTRIBUTION.md

@@ -90,8 +90,8 @@ The other built-in ICC profiles and the generated LUT looks are produced by code
 | `docs/images/preferences-apply-*.png` | Preferences before and after adding Apply (no artwork) | PhotoCraft contributors | PhotoCraft control-channel capture and offscreen `snapshot` example | MIT OR Apache-2.0 |
 | `docs/images/gradient-overlay-method-*.png` | Gradient Overlay Method selector, before and after (synthetic gradient) | @oRE-o | Rendered offscreen with the `snapshot` example; no external artwork | MIT OR Apache-2.0 |
 | `docs/images/cpu-pixel-alignment/*.png` | CPU canvas pixel alignment, before and after #8321 | PhotoCraft contributors | Original synthetic noise rendered with the offscreen `snapshot` example; see the adjacent README | MIT OR Apache-2.0, adjacent `LICENSE-MIT` and `LICENSE-APACHE` |
-| `docs/images/multi-channel-editing/{curves,curves-choices,levels,drawing}.png` | Selected colour channel editing (synthetic gradient) | @hidoba | Original synthetic gradient rendered with the offscreen `snapshot` example; adjacent JSON scripts | MIT OR Apache-2.0, adjacent `LICENSE-MIT` and `LICENSE-APACHE` |
+| `docs/images/multi-channel-editing/{curves,curves-choices,levels,drawing,mask-view-before,mask-view-after}.png` | Selected colour channel editing (synthetic gradient) | @hidoba | Original synthetic gradient rendered with the offscreen `snapshot` example; adjacent JSON scripts | MIT OR Apache-2.0, adjacent `LICENSE-MIT` and `LICENSE-APACHE` |
-| `docs/images/multi-channel-editing/great-wave.jpg`, `rgb.png`, `cmyk.png`, `lab.png` | *The Great Wave off Kanagawa*, c. 1830–1832, and PhotoCraft channel-selection captures | Katsushika Hokusai (artwork); PhotoCraft contributors (UI) | [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Tsunami_by_hokusai_19th_century.jpg), Metropolitan Museum reproduction; adjacent JSON capture scripts | Public domain artwork (PD-Art), adjacent `LICENSE-PUBLIC-DOMAIN.txt`; UI/scripts MIT OR Apache-2.0 |
+| `docs/images/multi-channel-editing/great-wave.jpg`, `rgb.png`, `cmyk.png`, `lab.png`, `gallery-channel-preview-{before,after}.png` | *The Great Wave off Kanagawa*, c. 1830–1832, and PhotoCraft channel-selection captures | Katsushika Hokusai (artwork); PhotoCraft contributors (UI) | [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Tsunami_by_hokusai_19th_century.jpg), Metropolitan Museum reproduction; adjacent JSON capture scripts | Public domain artwork (PD-Art), adjacent `LICENSE-PUBLIC-DOMAIN.txt`; UI/scripts MIT OR Apache-2.0 |
 
 Artwork shown in the screenshots (all public domain, via Wikimedia Commons; details in
 [`docs/images/SOURCES.md`](docs/images/SOURCES.md)):

docs/benchmarks/multi-channel-editing/environment.json

@@ -19,5 +19,27 @@
   "candidate_source_commit": "aeff53449221e8b42a628d832abc595c9503a146",
   "candidate_tone_source_sha256": "da42e686db09ed4e5bf2c19316a6b47261c97185aec83c6bba86831e29e39c6e",
   "before_fused_rerun_resources": "elapsed_seconds=16.47 peak_rss_kib=690516",
-  "before_fused_commit": "15bf0873ba03622e54189e668df20a1403e41d56"
+  "before_fused_commit": "15bf0873ba03622e54189e668df20a1403e41d56",
+  "liquify_preview": {
+    "source_content_commit": "009c4fa6128dad1e564d731656a304953d879842",
+    "build_git_head": "a37d21de7e1a90451d5afcad6772ae358f69e07a",
+    "binary_sha256": "309bc5e882403080ade9410103fba6eb73b296da897274a7816380f50e413c3a",
+    "files_sha256": {
+      "crates/ui-egui/examples/multi_channel_preview_bench.rs": "84f4e6fd4a0f79a35da706a06144401ad06509a06608ea5ed89729d394f6e0b1",
+      "crates/ui-egui/src/liquify_ui.rs": "1179cb7403fa189a8e0d1872212e150bd98b10844d189140e954cd0cdd279f29",
+      "crates/ui-egui/src/gallery_ui.rs": "118249270993f1443882df4808fd0f6e05b129a091441f3560bdcc0e4d80a4ca",
+      "crates/ui-egui/src/wide_angle_ui.rs": "6ebf9f1d291642dc3cc42c72980830f79e9f82c6d9b743c145e9048adddb1b36",
+      "crates/engine/src/color_channels.rs": "e6737a5dfb79a5324f08173d18cf271a539dddb386b9488249c150810537313e"
+    },
+    "measured_at_utc": "2026-10-25T17:45:11.612486+00:00",
+    "profile": "release, thin LTO",
+    "rayon_threads": 8,
+    "measurement": "CPU field deformation plus dirty native proxy render. GPU texture upload/presentation excluded. One warmup plus six interleaved updates; p50 is upper middle; max_ms is max of six. open_ms is one sequential setup timing per mode, not a median.",
+    "resources": {
+      "elapsed_seconds": 0.72,
+      "peak_rss_kib": 389664
+    },
+    "isolation": "Measured after final tests, builds and cargo xtask perf --quick ended; no Cargo or rustc processes were running.",
+    "correctness_proof": "Each workspace reports a nonzero Liquify maxDisplacement after the measured updates."
+  }
 }

docs/benchmarks/multi-channel-editing/liquify-preview.json

@@ -0,0 +1,54 @@
+{
+  "depth": 16,
+  "operation": "Liquify 120px live move; native proxy preview",
+  "repeats": 6,
+  "rows": [
+    {
+      "max_ms": 0.120119,
+      "open_ms": 22.648719,
+      "p50_ms": 0.110929,
+      "samples_ms": [
+        0.111069,
+        0.097649,
+        0.10152,
+        0.120119,
+        0.10755999999999999,
+        0.110929
+      ],
+      "target": "all"
+    },
+    {
+      "max_ms": 0.36013799999999996,
+      "open_ms": 246.61311,
+      "p50_ms": 0.34547799999999995,
+      "samples_ms": [
+        0.310718,
+        0.30684799999999995,
+        0.320127,
+        0.352098,
+        0.34547799999999995,
+        0.36013799999999996
+      ],
+      "target": "red"
+    },
+    {
+      "max_ms": 0.461107,
+      "open_ms": 317.70011900000003,
+      "p50_ms": 0.447017,
+      "samples_ms": [
+        0.397908,
+        0.394428,
+        0.416098,
+        0.448617,
+        0.447017,
+        0.461107
+      ],
+      "target": "red_blue"
+    }
+  ],
+  "size": [
+    6000,
+    4000
+  ],
+  "warmups": 1
+}

docs/images/multi-channel-editing/gallery-channel-preview-script.json

@@ -0,0 +1,51 @@
+[
+  [
+    "engine.execute",
+    {
+      "command": "image.imageSize",
+      "params": {
+        "width": 1000,
+        "resample": "bicubic"
+      }
+    }
+  ],
+  [
+    "engine.execute",
+    {
+      "command": "channel.target",
+      "params": {
+        "colors": [
+          0,
+          2
+        ]
+      }
+    }
+  ],
+  [
+    "engine.execute",
+    {
+      "command": "channel.setVisible",
+      "params": {
+        "channel": "composite",
+        "visible": true
+      }
+    }
+  ],
+  [
+    "ui.menu.invoke",
+    {
+      "id": "filter.filterGallery"
+    }
+  ],
+  [
+    "ui.menu.invoke",
+    {
+      "id": "filter.filterGallery",
+      "params": {
+        "ui": {
+          "filter": "cutout"
+        }
+      }
+    }
+  ]
+]

docs/images/multi-channel-editing/mask-view-script.json

@@ -0,0 +1,128 @@
+[
+  [
+    "engine.execute",
+    {
+      "command": "file.new",
+      "params": {
+        "width": 800,
+        "height": 560,
+        "depth": 16,
+        "background": "white"
+      }
+    }
+  ],
+  [
+    "engine.execute",
+    {
+      "command": "paint.gradient",
+      "params": {
+        "from": [
+          0,
+          0
+        ],
+        "to": [
+          800,
+          560
+        ],
+        "colors": [
+          "#143b9b",
+          "#f6b552"
+        ]
+      }
+    }
+  ],
+  [
+    "engine.execute",
+    {
+      "command": "layer.layerMask.revealAll",
+      "params": {}
+    }
+  ],
+  [
+    "engine.execute",
+    {
+      "command": "channel.target",
+      "params": {
+        "colors": [
+          0,
+          2
+        ]
+      }
+    }
+  ],
+  [
+    "engine.execute",
+    {
+      "command": "view.layerMask",
+      "params": {
+        "mode": "gray"
+      }
+    }
+  ],
+  [
+    "ui.set",
+    {
+      "tool": "brush",
+      "activeTabs": {
+        "middle": "channels"
+      },
+      "fit": true
+    }
+  ],
+  [
+    "engine.execute",
+    {
+      "command": "tools.setColors",
+      "params": {
+        "foreground": [
+          0,
+          0,
+          0,
+          1
+        ]
+      }
+    }
+  ],
+  [
+    "engine.execute",
+    {
+      "command": "tools.setBrush",
+      "params": {
+        "brush": {
+          "size": 70,
+          "hardness": 1.0,
+          "smoothing": {
+            "amount": 0.0
+          }
+        }
+      }
+    }
+  ],
+  [
+    "ui.pointer",
+    {
+      "events": [
+        {
+          "kind": "down",
+          "x": 150,
+          "y": 200
+        },
+        {
+          "kind": "move",
+          "x": 400,
+          "y": 280
+        },
+        {
+          "kind": "move",
+          "x": 650,
+          "y": 200
+        },
+        {
+          "kind": "up",
+          "x": 650,
+          "y": 200
+        }
+      ]
+    }
+  ]
+]

docs/multi-channel-editing.md

@@ -146,15 +146,30 @@ Raw samples: [original pre-feature base](benchmarks/multi-channel-editing/baseli
 [environment and binary hashes](benchmarks/multi-channel-editing/environment.json).
 The three `candidate*-before-fused-original.json` files preserve the original feature run.
 
-Validation: 6,472 engine and UI tests passed (38 ignored), including 53 focused engine
+Validation after the main merge and review fixes: 6,542 engine and UI tests passed
-regressions. Strict all-target Clippy, formatting, layering,
+(38 ignored), including 58 focused engine regressions. Strict all-target Clippy,
-wasm, parity generation and the adversarial command panic hunt passed. The complete
+formatting, layering, wasm, parity generation and the adversarial command panic hunt passed.
-`cargo xtask perf --quick` runner was attempted: its layout fixture fails because
+The complete `cargo xtask perf --quick` runner now finishes successfully after the main
-it tries to convert an already imported Smart Object. This unrelated runner failure is not
+merge; its report still lists unrelated, non-enforced budget overruns. Six further local
-reported as a passing full performance gate. The feature-specific benchmark above
+review/fix rounds followed the latest CodeRabbit review; the last found no actionable issues.
-completed successfully. Eleven original review/fix rounds and four follow-up reviews were completed; the
+All visual captures were rendered offscreen and inspected.
-latest review found no actionable issues. Visual captures were rendered offscreen
+
-and inspected.
+The additional 24 MP RGB16 Liquify benchmark uses
+`crates/ui-egui/examples/multi_channel_preview_bench.rs`, with eight Rayon workers and
+no concurrent builds, tests or performance scenarios. It measures field deformation plus
+the dirty CPU proxy render; GPU uploads/presentation are excluded. One warmup and six
+measured updates use interleaved target modes. The field's nonzero displacement is checked.
+
+| Liquify, 120 px brush | All channels | Red only | Red + Blue |
+|---|---:|---:|---:|
+| Preview update p50 | 0.111 ms | 0.345 ms | 0.447 ms |
+| Maximum of six updates | 0.120 ms | 0.360 ms | 0.461 ms |
+| Open workspace, one setup measurement | 22.6 ms | 246.6 ms | 317.7 ms |
+
+Opening a component workspace builds its native proxy once. Open timings are sequential
+single observations, not medians; setup is excluded from update timings. The whole process,
+including all three workspaces, peaked at 380.5 MiB RSS. [Raw samples](benchmarks/multi-channel-editing/liquify-preview.json)
+and [source/binary hashes](benchmarks/multi-channel-editing/environment.json) are retained.
 
 
 ## Visual evidence
@@ -200,3 +215,59 @@ retouch-preview restriction issues are fixed, with regression tests. The propose
 clipboard inversion is unnecessary: destination extraction and scatter already convert
 between tone and ink. Tests cover implicit/explicit singleton copying into explicit targets
 and normal/Paste Into/Paste Outside paths at 8/16/32-bit depths without adding an inversion.
+
+The post-merge review identified missing Copy/Cut parameter documentation; both commands
+now describe explicit colour targets and layer ids/names. Auditing that contract also found
+that Copy ignored an explicit layer with an implicit single-component target. Copy now
+resolves that layer just as Cut does, with a regression that failed before the correction.
+
+The proposed Lab histogram index change is unnecessary: `HistSource::Colors` reserves
+slot 0 for the combined selection and stores native components at `k + 1`, including Lab.
+Ordinary Lab histograms instead use slots 0–2 for L/a/b. The histogram accessor returns
+empty bins for an unavailable slot, rather than panicking. New tests use actual native
+subset histograms for components `[0, 2]`, render every choice in both editors, and check
+Levels Auto against those bins in RGB/CMYK/Lab at 8/16/32-bit depths.
+
+The next local review found that viewing a layer mask after selecting colour channels
+could still send canvas strokes to those colours. Mask view now takes priority in canvas
+painting, implicit engine commands and captured tone-dialog targets. Regressions cover
+live previews and commits plus adjustments/filters at all depths, while explicit native
+targets can still override the viewed mask. Selecting colour rows again leaves mask view
+and restores their editing target and visibility.
+
+A further review caught mask Cut/Clear falling back to layer pixels, dialog capture retaining
+the old colour set over a viewed mask, and Desaturate dropping explicit target parameters.
+Cut/Clear now copy/fill only the selected mask samples, respecting locks and feathering.
+Adjustment/filter dialogs preserve their captured mask through preview, confirmation and
+Curves Reset, and Desaturate forwards its target and layer parameters. Tests cover pixel and
+clipboard preservation, undo/redo, refused edits and changed panel selections.
+Move/Free Transform still work on the viewed unlinked mask when colour rows remain selected
+behind it; native colour subsets retain their geometry restriction. Curves canvas-point
+gestures also honour the captured scalar target after the panel selection changes.
+
+The named-destination visibility guard now resolves layer names just as painting does.
+Filter Gallery, Liquify and Adaptive Wide Angle capture the native colour target, preserve
+unselected components and alpha in their specialized previews, and retain the target for OK.
+Liquify samples only the dirty proxy or detail viewport, with a native proxy built once.
+These full-window workspaces require layer pixels or native colour channels; masks, saved
+channels and Quick Mask remain available through ordinary filter commands/dialogs.
+Geometric writeback retains the original alpha layout, copying selected native bytes even
+when the warp produces an alpha-bearing surface. Changed defaults materialize only within
+the supplied document/preview extent, under the same bounded-pixel limit.
+
+The public-domain Filter Gallery comparison uses R+B with Green manually made visible.
+The original preview filters Green too; the corrected preview retains its original detail.
+The [capture script](images/multi-channel-editing/gallery-channel-preview-script.json)
+records that explicit visibility override.
+
+![Before: Cutout also changes Green](images/multi-channel-editing/gallery-channel-preview-before.png)
+
+![After: Cutout preserves unselected Green](images/multi-channel-editing/gallery-channel-preview-after.png)
+
+The same synthetic gradient and [pointer script](images/multi-channel-editing/mask-view-script.json)
+show the correction: before, the mask stays white while the stroke changes the layer;
+after, the stroke paints the mask while the layer's gradient stays intact.
+
+![Before: the displayed mask stays white](images/multi-channel-editing/mask-view-before.png)
+
+![After: the displayed mask receives the stroke](images/multi-channel-editing/mask-view-after.png)