Map Light; record SectionSymbol as blocked

Light placement, intensity, colour, attenuation and shadow fields are
writable with host validation. staged_python_light_lifecycle_over_real_ipc
passes every gate except DXF cast_shadows, pinned by a canary.
SectionSymbol is recorded as blocked: it needs host-created style and view
representation objects and its raw point counts have no documented
derivation.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

crates/ocs_plugin_api/build.rs

@@ -796,6 +796,7 @@ fn generate_entity_coverage(out_dir: &Path, registry: &TypeRegistry) {
                     | ("Underlay", _)
                     | ("Viewport", _)
                     | ("ViewBorder", _)
+                    | ("Light", _)
                     | (
                         "MLine",
                         "flags"

crates/ocs_plugin_api/entity_coverage_policy.json

@@ -462,6 +462,29 @@
       "rotation_angle",
       "active_viewport",
       "scale_handle"
+    ],
+    "Light": [
+      "layer",
+      "name",
+      "light_type",
+      "position",
+      "target",
+      "status",
+      "light_color",
+      "plot_glyph",
+      "intensity",
+      "attenuation_type",
+      "use_attenuation_limits",
+      "attenuation_start_limit",
+      "attenuation_end_limit",
+      "hotspot_angle",
+      "falloff_angle",
+      "cast_shadows",
+      "shadow_type",
+      "shadow_map_size",
+      "shadow_map_softness",
+      "photometric_mode",
+      "photometric_data"
     ]
   },
   "readable": {
@@ -566,6 +589,9 @@
     ],
     "ViewBorder": [
       "version"
+    ],
+    "Light": [
+      "class_version"
     ]
   },
   "aliases": {

crates/ocs_plugin_api/src/entity_coverage.rs

@@ -975,6 +975,51 @@ fn validate_view_border(
     Ok(())
 }
 
+/// Light: type, placement, intensity, attenuation and shadow settings.
+#[cfg(feature = "host")]
+fn validate_light(
+    old: Option<&crate::host::acadrust::entities::Light>,
+    new: &crate::host::acadrust::entities::Light,
+) -> Result<(), String> {
+    if old == Some(new) {
+        return Ok(());
+    }
+    if new.name.trim().is_empty() {
+        return Err("Light.name is empty".into());
+    }
+    if !(1..=3).contains(&new.light_type) {
+        return Err("Light.light_type must be 1 (distant), 2 (point) or 3 (spot)".into());
+    }
+    finite_vector("Light.position", &new.position)?;
+    finite_vector("Light.target", &new.target)?;
+    if new.light_type != 2 && new.position == new.target {
+        return Err("a distant or spot Light needs a target different from its position".into());
+    }
+    if !new.intensity.is_finite() || new.intensity < 0.0 {
+        return Err("Light.intensity must be finite and non-negative".into());
+    }
+    for (name, value) in [
+        ("attenuation_start_limit", new.attenuation_start_limit),
+        ("attenuation_end_limit", new.attenuation_end_limit),
+        ("hotspot_angle", new.hotspot_angle),
+        ("falloff_angle", new.falloff_angle),
+    ] {
+        if !value.is_finite() || value < 0.0 {
+            return Err(format!("Light.{name} must be finite and non-negative"));
+        }
+    }
+    if new.use_attenuation_limits && new.attenuation_start_limit > new.attenuation_end_limit {
+        return Err("Light attenuation start limit must not exceed the end limit".into());
+    }
+    if new.light_type == 3 && new.hotspot_angle > new.falloff_angle {
+        return Err("Light.hotspot_angle must not exceed falloff_angle".into());
+    }
+    if new.shadow_map_size < 0 {
+        return Err("Light.shadow_map_size must be non-negative".into());
+    }
+    Ok(())
+}
+
 /// Validate newly created geometry for the kinds whose mapped fields have
 /// host checks. Called by the Python add path before an entity enters the document.
 #[cfg(feature = "host")]
@@ -1080,6 +1125,7 @@ pub fn validate_new_canvas_entity(entity: &crate::host::EntityType) -> Result<()
         EntityType::Underlay(value) => validate_underlay(None, value)?,
         EntityType::Viewport(value) => validate_viewport(None, value)?,
         EntityType::ViewBorder(value) => validate_view_border(None, value)?,
+        EntityType::Light(value) => validate_light(None, value)?,
         EntityType::AttributeDefinition(value) => {
             finite_vector(
                 "AttributeDefinition.insertion_point",
@@ -1446,6 +1492,7 @@ pub fn validate_entity_mutation(
         (EntityType::Underlay(old), EntityType::Underlay(new)) => validate_underlay(Some(old), new)?,
         (EntityType::Viewport(old), EntityType::Viewport(new)) => validate_viewport(Some(old), new)?,
         (EntityType::ViewBorder(old), EntityType::ViewBorder(new)) => validate_view_border(Some(old), new)?,
+        (EntityType::Light(old), EntityType::Light(new)) => validate_light(Some(old), new)?,
         (EntityType::MLine(old), EntityType::MLine(new)) => validate_mline(Some(old), new)?,
         (EntityType::Leader(old), EntityType::Leader(new)) => validate_leader(Some(old), new)?,
         (EntityType::AttributeDefinition(old), EntityType::AttributeDefinition(new)) => {
@@ -2184,6 +2231,7 @@ mod tests {
                         | "Underlay"
                         | "Viewport"
                         | "ViewBorder"
+                        | "Light"
                 )
             {
                 assert!(
@@ -2506,6 +2554,26 @@ mod tests {
                 "ViewBorder.rotation_angle".to_owned(),
                 "ViewBorder.active_viewport".to_owned(),
                 "ViewBorder.scale_handle".to_owned(),
+                "Light.name".to_owned(),
+                "Light.light_type".to_owned(),
+                "Light.position".to_owned(),
+                "Light.target".to_owned(),
+                "Light.status".to_owned(),
+                "Light.light_color".to_owned(),
+                "Light.plot_glyph".to_owned(),
+                "Light.intensity".to_owned(),
+                "Light.attenuation_type".to_owned(),
+                "Light.use_attenuation_limits".to_owned(),
+                "Light.attenuation_start_limit".to_owned(),
+                "Light.attenuation_end_limit".to_owned(),
+                "Light.hotspot_angle".to_owned(),
+                "Light.falloff_angle".to_owned(),
+                "Light.cast_shadows".to_owned(),
+                "Light.shadow_type".to_owned(),
+                "Light.shadow_map_size".to_owned(),
+                "Light.shadow_map_softness".to_owned(),
+                "Light.photometric_mode".to_owned(),
+                "Light.photometric_data".to_owned(),
             ])
         );
     }

docs/plugin-host-model-completion-plan.md

@@ -7,13 +7,13 @@ Build a general Python document model over the OCS host API for all **43 canvas
 As of 20 September 2026, the working branch is `plugin/host-model-api` at
 `a8dd3640` plus the Leader increment, published as draft PR
 [#1391](https://github.com/HakanSeven12/OpenCADStudio/pull/1391). Host API is
-v7. The Python feature has explicit writes for **36 of 43** canvas kinds: 35
+v7. The Python feature has explicit writes for **37 of 43** canvas kinds: 36
-are creatable and `Insert` remains update-only. This is **not** 36 completed
+are creatable and `Insert` remains update-only. This is **not** 37 completed
 kinds: Tolerance, Shape, AttributeEntity, Hatch, MLine, Dimension, MultiLeader, Table, PolygonMesh, PolyfaceMesh, Mesh and Wipeout pass every completion gate.
 AttributeDefinition passes its host and real IPC lifecycle but remains short of
 `Complete` because the previously pinned CAD codec dropped optional ATTDEF
 fields during DXF reads; revalidate that blocker against the current
-`acadrust` revision `7ea4247`. Leader is mapped and integration-tested but blocked at W by three acadrust persistence gaps (see the ledger). Leader, Helix, Underlay and ViewBorder are mapped and integration-tested but blocked at W by acadrust persistence gaps, and RasterImage and Viewport are held short of `Complete` by unverifiable or missing oracles (see the ledger). RasterImage is mapped and integration-tested, held short of `Complete` by unverifiable image-dictionary linkage. The other 7 canvas kinds have only `layer`
+`acadrust` revision `7ea4247`. Leader is mapped and integration-tested but blocked at W by three acadrust persistence gaps (see the ledger). Leader, Helix, Underlay, ViewBorder and Light are mapped and integration-tested but blocked at W by acadrust persistence gaps, and RasterImage and Viewport are held short of `Complete` by unverifiable or missing oracles (see the ledger). RasterImage is mapped and integration-tested, held short of `Complete` by unverifiable image-dictionary linkage. The other 6 canvas kinds have only `layer` (SectionSymbol is recorded as blocked)
 writes through the document model. All 43 have raw typed snapshots. There are
 three internal records and two opaque fallbacks outside the 43 canvas kinds.
 
@@ -123,7 +123,7 @@ The last five may require new engine capabilities rather than only Python conver
 
 ## Handoff start point
 
-Continue with **SectionSymbol** (queue item 15). Leader is done except for its W
+Continue with **Region** (queue item 17). SectionSymbol (item 15) is blocked; see the ledger. Leader is done except for its W
 gate; when the engine writes DXF group 340, reads group 213 and the DWG
 R2010+ text-size question is decided, flip the canary assertions in
 `staged_python_leader_lifecycle_over_real_ipc` and mark it `Complete`.
@@ -169,3 +169,4 @@ exact queue above and update statuses with evidence after each increment.
 - Mapped `Underlay` against a fixture PDF `UnderlayDefinition`. All gates pass except DXF W: the reader does not convert the degree-valued rotation back to radians, and repeated DXF round trips compound the error (pinned by a canary). The queue now continues with `Viewport`.
 - Mapped `Viewport` with a paper-space owner rule and frozen-layer reference validation. Every gate except a paper-space canvas oracle passes through the shared driver; the kind stays integration-tested. The queue now continues with `ViewBorder`.
 - Mapped `ViewBorder` with viewport and scale reference rules. All gates pass in DWG; DXF loading does not restore the typed entity (pinned by a canary). The queue now continues with `SectionSymbol`.
+- Recorded `SectionSymbol` (queue item 15) as **blocked**: it needs a section view style and view representation the host cannot create, and its raw point-count fields have no documented derivation. Mapped `Light` (item 16); every gate passes except DXF `cast_shadows`, which the reader drops (pinned by a canary). The queue now continues with `Region`.

docs/plugin-host-model-coverage-ledger.md

@@ -1,6 +1,6 @@
 # OCS canvas kind coverage ledger
 
-Use with [the completion plan](plugin-host-model-completion-plan.md). This ledger is current as of 20 September 2026: **36 of 43 canvas kinds have explicit geometry writes** (35 creatable, plus update-only `Insert`), **12 kinds are complete**, and 7 remain layer-only. `Mapped` means at least one non-layer field is exposed for Python writes; it does **not** mean the kind passes the completion gate. `Update-only` means Python creation is unavailable. `Layer-only` means raw inspection and canvas layer edits exist, but geometry is not mapped. Record actual evidence or a blocking issue before changing any status to `Complete`.
+Use with [the completion plan](plugin-host-model-completion-plan.md). This ledger is current as of 20 September 2026: **37 of 43 canvas kinds have explicit geometry writes** (36 creatable, plus update-only `Insert`), **12 kinds are complete**, and 6 remain layer-only (one of them, SectionSymbol, blocked). `Mapped` means at least one non-layer field is exposed for Python writes; it does **not** mean the kind passes the completion gate. `Update-only` means Python creation is unavailable. `Layer-only` means raw inspection and canvas layer edits exist, but geometry is not mapped. Record actual evidence or a blocking issue before changing any status to `Complete`.
 
 Completion gate codes: **C** = create through Python document model; **R** = read; **E** = edit defining geometry and another property; **D** = delete; **U** = undo/redo and atomic failure; **I** = real IPC plus GUI/canvas pick or observable behavior; **W** = DWG and DXF save/reopen; **V** = invalid-input checks and untouched-field/reference preservation; **P** = build and load the in-tree bundled plugin with a manifest matching the host toolchain and acadrust source. A kind is `Complete` only when **C/R/E/D/U/I/W/V/P** all pass and its property catalog matches implementation. `Blocked` requires a specific dependency or failing fixture.
 
@@ -42,8 +42,8 @@ Completion gate codes: **C** = create through Python document model; **R** = rea
 | Underlay | **Integration-tested / blocked at W by acadrust (DXF rotation units)** | Writable: `underlay_type` and `definition_handle` (both fixed by the definition: creation names an existing `UnderlayDefinition`, and a mismatched type or missing definition is rejected), `insertion_point`, `x_scale`, `y_scale`, `z_scale`, `rotation`, `normal`, `flags`, `contrast`, `fade`, `clip_boundary_vertices`, `clip_inverted`. The file path and page live on the definition object, which scripts cannot create or list yet; they reference one the drawing already owns. Host validation requires finite nonzero scales, a finite rotation, a nonzero normal, contrast/fade within 0..=100, known flags, finite clip vertices (none, or at least 2) and an existing definition of the same type. `staged_python_underlay_lifecycle_over_real_ipc` (shared `run_mesh_lifecycle` with a fixture PDF definition) passes C/R/E/D/U/I/V/P and DWG W: creation, a placement/scale/rotation/contrast/fade/clip transaction, canvas wires, eight rejection cases plus an atomic rollback, DWG reopen and re-edit, and three-step undo/redo. **W blocker (engine, pinned by canary assertions):** DXF stores the rotation in degrees but the reader returns it unconverted, so 0.5 rad reopens as 28.6 and each further DXF save-reopen compounds it (1641.4 after a second), silently corrupting the rotation. Not `Complete` until the reader converts degrees back to radians. Not covered: creating definitions from a file path, DWF/DGN fixtures. |
 | Viewport | **Integration-tested** | Writable: `center`, `width`, `height`, `status`, `view_center`, `view_direction`, `view_target`, `lens_length`, `front_clip_z`, `back_clip_z`, `view_height`, `twist_angle`, `custom_scale`, `frozen_layers` (layer handles), `render_mode`, `circle_sides`, `ucs_icon_visible`. Read-only: `id`, snap/grid settings, UCS fields, `clip_boundary_handle`, `style_sheet`, shade-plot, background, visual-style and sun handles, lighting, `ambient_color`, `elevation`. Reference rules: the owner must be a paper-space layout block (a model-space viewport is rejected) and every frozen-layer handle must be an existing layer. Host validation requires finite centers, positive width, height, view height, lens length and scale, a nonzero view direction, finite clip planes and twist, and at least 3 circle sides. `staged_python_viewport_lifecycle_over_real_ipc` (shared `run_mesh_lifecycle`, paper-space owner supplied by the driver) passes C/R/E/D/U/V/W/P: creation in the paper-space block, a move/resize/view-height/twist/frozen-layer transaction, seven rejection cases plus an atomic rollback, DWG and DXF reopen with re-edit, and three-step undo/redo. **Why not `Complete`:** the I gate lacks a canvas oracle because a paper-space viewport only draws on its layout tab, which the driver does not activate; viewport `id` uniqueness within a layout, clip boundary entities and view-to-scale synchronization are not handled by the host. |
 | ViewBorder | **Integration-tested / blocked at W by acadrust (DXF kind)** | Writable: `min`, `max`, `center` (2-D pairs), `scale`, `rotation_angle`, `active_viewport` and `scale_handle` (both required at creation). `version` is read-only. Reference rules: `active_viewport` must be an existing Viewport entity and `scale_handle` an existing `Scale` object. Host validation requires finite bounds with `min` below `max` on both axes, a positive scale and a finite rotation. `staged_python_view_border_lifecycle_over_real_ipc` (shared `run_mesh_lifecycle`, driver-made viewport and scale fixtures) passes C/R/E/D/U/I/V/P and DWG W: creation, a resize/recenter/scale/rotation transaction, canvas wires, seven rejection cases plus an atomic rollback, DWG reopen and re-edit, and three-step undo/redo. **W blocker (engine, pinned by a canary):** a DXF `DRAWINGVIEW` reopens as a different, opaque entity kind rather than as a ViewBorder, so only DWG restores the typed record. Not `Complete` until DXF loading restores the typed entity. Not covered: the linked view representation and drawing-view definition records. |
-| SectionSymbol | Layer-only | Requires section-view style and point records. |
+| SectionSymbol | **Blocked** | Not mapped. A valid section mark needs a `SectionViewStyle` and a `ViewRep` view-representation object that a script cannot create through the host API, and the entity stores raw point counts and flag words (`raw_point_count_90`, `raw_flags_90`, `raw_point_record_count`, `raw_view_symbol_70`) whose relationship to `points` is undocumented in acadrust and is written back verbatim by both writers, so the host cannot keep them consistent after a scripted edit without guessing. Adding the kind needs (1) host-side creation or lookup of a section style and view representation, and (2) a confirmed derivation of the raw counts from a real DWG produced by another CAD application. The kind keeps raw snapshot access and layer edits. |
-| Light | Layer-only | Requires position/target and photometric-state fixture. |
+| Light | **Integration-tested / blocked at W by acadrust (DXF `cast_shadows`)** | Writable: `name`, `light_type` (1 distant, 2 point, 3 spot), `position`, `target`, `status`, `light_color`, `plot_glyph`, `intensity`, the attenuation type and limits, `hotspot_angle`, `falloff_angle`, `cast_shadows`, `shadow_type`, `shadow_map_size`, `shadow_map_softness`, `photometric_mode`, `photometric_data`; `class_version` is read-only. Host validation requires a non-empty name, a known light type, finite placement, a spot or distant target that differs from the position, non-negative intensity, angles and limits, an attenuation start not above its end, a spot hotspot not above its falloff, and a non-negative shadow map size. `staged_python_light_lifecycle_over_real_ipc` (shared `run_mesh_lifecycle`) passes C/R/E/D/U/I/V/P and DWG W: a spot light with an RGB colour, an intensity/target/position/shadow transaction that preserves the colour and untouched fields, the canvas glyph, eight rejection cases plus an atomic rollback, DWG reopen and re-edit, and three-step undo/redo. **W blocker (engine, pinned by a canary):** the DXF reader does not restore `cast_shadows`, which reopens false; colour, placement and intensity persist. Not covered: photometric web data edits and sun/skylight objects. |
 | Region | Layer-only | Requires valid ACIS region payload. |
 | Body | Layer-only | Requires valid ACIS body payload. |
 | Solid3D | Layer-only | Requires valid ACIS solid payload. |

docs/plugin-host-model.md

@@ -35,7 +35,7 @@ attached attribute and sequence records. Those fields report `transaction_geomet
 catalog. All 43 canvas kinds also support nonempty `layer` changes through
 the same undoable transaction; internal and opaque variants remain read-only
 through the document model. The adapter accepts only `layer` patches for
-canvas kinds outside its 36 geometry converters. Other writable properties
+canvas kinds outside its 37 geometry converters. Other writable properties
 still report `type_conversion_only`; broader CAD range and cross-property
 checks remain outstanding.
 The host's `entity_snapshot` helper serializes any typed entity as a detached
@@ -91,7 +91,7 @@ Input tokens are bound to the drawing tab that requested the pick. Polling a
 token from another tab returns no result and does not consume it.
 
 Python `doc.entities[handle]` returns a descriptor for every entity. For kinds
-outside the 36-kind generated schema it contains only handle, kind, and layer;
+outside the 37-kind generated schema it contains only handle, kind, and layer;
 `layer` is editable on canvas kinds. `doc.coverage()` enumerates the
 catalog; `doc.coverage("Line")` and `line.coverage` return one entry. For
 covered kinds, the coverage object lists actual readable and editable

plugins/opencad-python/README.md

@@ -94,7 +94,7 @@ The host-owned catalog classifies all 48 entity variants and tracks every
 traced field, including fields marked `unmapped`. Query it with
 `doc.coverage()` or `doc.coverage("Line")`; each row includes source field,
 type, access, and current validation status. Geometry edits remain limited to
-the 36 mapped kinds.
+the 37 mapped kinds.
 For any entity, `entity.snapshot` returns a detached dictionary of its raw
 CAD fields, including `snapshot["common"]` and kind-specific nested values.
 It can inspect an unmapped kind; editing the dictionary does

plugins/opencad-python/entity_manifest.json

@@ -35,7 +35,8 @@
     "Wipeout",
     "Underlay",
     "Viewport",
-    "ViewBorder"
+    "ViewBorder",
+    "Light"
   ],
   "manual_kinds": ["Dimension"],
   "base_fields": ["handle", "layer", "owner_handle"],
@@ -413,6 +414,13 @@
         "active_viewport": { "required": true },
         "scale_handle": { "required": true }
       }
+    },
+    "Light": {
+      "fields": {
+        "class_version": { "read_only": true },
+        "position": { "required": true },
+        "name": { "required": true }
+      }
     }
   }
 }

plugins/opencad-python/src/ocs_module.rs

@@ -4756,7 +4756,7 @@ mod tests {
                 );
             }
         }
-        assert_eq!(emitted.len(), 36);
+        assert_eq!(emitted.len(), 37);
     }
 
     #[cfg(feature = "experimental-host-model")]

src/app/plugin_host.rs

@@ -3691,6 +3691,48 @@ mod tests {
         });
     }
 
+    #[test]
+    fn staged_python_light_lifecycle_over_real_ipc() {
+        run_mesh_lifecycle(&MeshCase {
+            create: concat!(
+                "doc.create_entity('Light', name='Key', light_type=3, position=P(10.0, 10.0, 10.0),\n",
+                "    target=P(0.0, 0.0, 0.0), intensity=1.5, hotspot_angle=0.4, falloff_angle=0.8,\n",
+                "    light_color={'kind': 'Rgb', 'value': {'r': 255, 'g': 240, 'b': 200}})\n"),
+            edit: concat!(
+                "lt = doc.entities[HANDLE]\n",
+                "with doc.transaction('Edit light'):\n",
+                "    lt.intensity = 3.0\n",
+                "    lt.target = (5.0, 5.0, 0.0)\n",
+                "    lt.position = (12.0, 8.0, 10.0)\n",
+                "    lt.cast_shadows = True\n",
+                "doc.selection = [lt]\n"),
+            rejects: &[
+                ("'light_type':9", "must be 1 (distant)"),
+                ("'intensity':-1.0", "non-negative"),
+                ("'target':{'x':12.0,'y':8.0,'z':10.0}", "different from its position"),
+                ("'hotspot_angle':2.0", "must not exceed falloff_angle"),
+                ("'position':{'x':float('nan'),'y':0.0,'z':0.0}", "finite"),
+                ("'name':''", "empty"),
+                ("'class_version':2", "read-only"),
+                ("'light_color':{'kind':'Index','value':300}", "Color"),
+            ],
+            is_kind: |entity| matches!(entity, EntityType::Light(_)),
+            digest: |entity| match entity {
+                EntityType::Light(l) => format!("{} t{} i{:.1} pos{:.0},{:.0},{:.0} tgt{:.0},{:.0} sh{} {:?}", l.name, l.light_type,
+                    l.intensity, l.position.x, l.position.y, l.position.z, l.target.x, l.target.y, l.cast_shadows, l.light_color),
+                _ => "wrong kind".into(),
+            },
+            reedit: |entity| if let EntityType::Light(l) = entity { l.intensity = 4.0; },
+            expect_created: "Key t3 i1.5 pos10,10,10 tgt0,0 shfalse Rgb { r: 255, g: 240, b: 200 }",
+            expect_edited: "Key t3 i3.0 pos12,8,10 tgt5,5 shtrue Rgb { r: 255, g: 240, b: 200 }",
+            expect_reedited: "Key t3 i4.0 pos12,8,10 tgt5,5 shtrue Rgb { r: 255, g: 240, b: 200 }",
+            // BLOCKER: DXF does not restore `cast_shadows` (it reopens false),
+            // like the other boolean groups the reader parses as integers.
+            expect_edited_dxf: "Key t3 i3.0 pos12,8,10 tgt5,5 shfalse Rgb { r: 255, g: 240, b: 200 }",
+            expect_reedited_dxf: "Key t3 i4.0 pos12,8,10 tgt5,5 shfalse Rgb { r: 255, g: 240, b: 200 }",
+        });
+    }
+
     #[test]
     fn staged_python_point_pick_and_cancel_over_real_ipc() {
         let Some(plugin_path) = std::env::var_os("OCS_TEST_PYTHON_PLUGIN") else {