feat(block-editor): wire Rotation, Alignment and Flip parameter placement

Enable the existing palette rows and BPARAMETER choices. Rotation accepts a
center, picked or numeric radius, and picked or numeric default angle.
Alignment places a tangent direction from its base point. Flip places a
reflection line and state label, with native grip and state expressions.

Extend shared graph append/capacity checks for Flip's additional state node
while preserving existing subgraphs. Keep Polar/Rotation angle labels unique
in either placement order. Add editor graphics, extents and definition
reframing through the existing overlay/history/save paths.

This milestone implements native parameter placement and persistence.
Rotate/Flip action association, reference alignment/grip editing, parameter
property editing and parameter sets remain separate work.

Validation covers command and palette placement, cancellation, local/parent
undo, save/discard, native DWG/DXF objects, existing graph preservation and
the 17 research fixtures. Broader block/dock regressions and editor renders
are also checked.

src/app/block_editor_tests.rs

@@ -86,6 +86,155 @@ fn distance_parameter_count(app: &OpenCADStudio) -> usize {
     crate::scene::block_distance_parameter::parameters(&tab.scene.document, definition).len()
 }
 
+fn orientation_parameter_count(app: &OpenCADStudio) -> usize {
+    let tab = &app.tabs[app.active_tab];
+    let definition = tab
+        .scene
+        .document
+        .block_records
+        .get("EDIT_ME")
+        .unwrap()
+        .handle;
+    crate::scene::block_orientation_parameter::parameters(&tab.scene.document, definition).len()
+}
+
+#[test]
+fn orientation_parameter_batch_numeric_rotation_local_history_save_and_parent_undo() {
+    let (mut app, reference) = fixture();
+    begin(&mut app, reference);
+    let i = app.active_tab;
+    for (index, (kind, inputs)) in [
+        ("ROTATION", vec!["0,0", "2", "90"]),
+        ("ALIGNMENT", vec!["0,0", "0,2"]),
+        ("FLIP", vec!["0,0", "0,2", "3,3"]),
+    ]
+    .into_iter()
+    .enumerate()
+    {
+        let before = app.tabs[i].scene.document.clone();
+        let _ = app.dispatch_command(&format!("BPARAMETER {kind}"));
+        for text in &inputs[..inputs.len() - 1] {
+            feed(&mut app, text);
+            assert_eq!(app.tabs[i].scene.document, before, "incomplete placement");
+        }
+        feed(&mut app, inputs.last().unwrap());
+        assert_eq!(orientation_parameter_count(&app), index + 1, "{kind}");
+        assert_eq!(app.tabs[i].history.undo_stack.len(), index + 1);
+        assert!(app.tabs[i].scene.preview_wires.is_empty());
+        app.undo_steps(1);
+        assert_eq!(orientation_parameter_count(&app), index);
+        app.redo_steps(1);
+        assert_eq!(orientation_parameter_count(&app), index + 1);
+    }
+    let definition = app.tabs[i].active_block_edit_session().unwrap().br_handle;
+    let p = &crate::scene::block_orientation_parameter::parameters(
+        &app.tabs[i].scene.document,
+        definition,
+    )[0];
+    assert!((p.native.definition_end_point - Vector3::new(0.0, 2.0, 0.0)).length() < 1e-10);
+    assert_eq!(p.reference, Vector3::new(2.0, 0.0, 0.0));
+    let editor = app.tabs[i].scene.document.clone();
+    let _ = app.dispatch_command("BTESTBLOCK");
+    assert!(app.tabs[app.active_tab]
+        .active_block_edit_session()
+        .is_none());
+    assert_eq!(
+        app.tabs[app.active_tab]
+            .scene
+            .document
+            .entities_in_block("EDIT_ME")
+            .count(),
+        1
+    );
+    let _ = app.dispatch_command("BCLOSETESTBLOCK");
+    assert_eq!(app.tabs[i].scene.document, editor);
+    let _ = app.run_command_line("UCS ORIGIN 1,2,0");
+    for p in crate::scene::block_orientation_parameter::parameters(
+        &app.tabs[i].scene.document,
+        definition,
+    ) {
+        assert_eq!(
+            p.native.definition_base_point,
+            Vector3::new(-1.0, -2.0, 0.0)
+        );
+    }
+    let _ = app.dispatch_command("BSAVE");
+    let _ = app.dispatch_command("BEDIT_DISCARD");
+    assert_eq!(orientation_parameter_count(&app), 3);
+    app.undo_steps(1);
+    assert_eq!(orientation_parameter_count(&app), 0);
+    app.redo_steps(1);
+    assert_eq!(orientation_parameter_count(&app), 3);
+}
+
+#[test]
+fn orientation_parameter_chooser_cancels_invalid_picks_and_rotation_default_angle() {
+    let (mut app, reference) = fixture();
+    begin(&mut app, reference);
+    let i = app.active_tab;
+    let before = app.tabs[i].scene.document.clone();
+    for (kind, maximum) in [("R", 2), ("A", 1), ("F", 2)] {
+        for picks in 0..=maximum {
+            let _ = app.dispatch_command("BPARAMETER");
+            feed(&mut app, kind);
+            if picks > 0 {
+                feed(&mut app, "0,0");
+                feed(&mut app, "0,0");
+                assert_eq!(app.tabs[i].scene.document, before);
+            }
+            if picks > 1 {
+                feed(&mut app, "0,2");
+            }
+            let _ = app.update(Message::CommandEscape);
+            assert_eq!(app.tabs[i].scene.document, before);
+            assert!(app.tabs[i].history.undo_stack.is_empty());
+        }
+    }
+    let _ = app.dispatch_command("BPARAMETER ROTATION");
+    feed(&mut app, "0,0");
+    feed(&mut app, "-2");
+    assert_eq!(app.tabs[i].scene.document, before);
+    feed(&mut app, "2");
+    feed(&mut app, "");
+    assert_eq!(orientation_parameter_count(&app), 1);
+    let _ = app.dispatch_command("BEDIT_DISCARD");
+    assert_eq!(orientation_parameter_count(&app), 0);
+    let _ = app.dispatch_command("LINE");
+    for kind in ["ROTATION", "ALIGNMENT", "FLIP"] {
+        let _ = app.dispatch_command(&format!("BPARAMETER {kind}"));
+        assert_eq!(app.tabs[i].active_cmd.as_ref().unwrap().name(), "LINE");
+    }
+}
+
+#[test]
+fn orientation_parameter_stale_context_and_invalid_result_do_not_start_history() {
+    use crate::scene::block_orientation_parameter::Kind;
+    let (mut app, reference) = fixture();
+    begin(&mut app, reference);
+    let i = app.active_tab;
+    let definition = app.tabs[i].active_block_edit_session().unwrap().br_handle;
+    let id = app.tabs[i].id;
+    let before = app.tabs[i].scene.document.clone();
+    for (document_id, end) in [
+        (id + 1, glam::DVec3::Y),
+        (id, glam::DVec3::ZERO),
+        (id, glam::DVec3::splat(f64::NAN)),
+    ] {
+        let _ = app.handle_place_block_orientation_parameter(
+            crate::command::CmdResult::PlaceBlockOrientationParameter {
+                document_id,
+                definition,
+                kind: Kind::Flip,
+                base: glam::DVec3::ZERO,
+                end,
+                reference: glam::DVec3::X,
+            },
+        );
+        assert_eq!(app.tabs[i].scene.document, before);
+        assert!(app.tabs[i].history.undo_stack.is_empty());
+    }
+}
+
 #[test]
 fn distance_parameter_batch_three_picks_local_undo_redo_and_saved_parent_undo() {
     let (mut app, reference) = fixture();

src/app/command_driver/mod.rs

@@ -575,6 +575,9 @@ impl OpenCADStudio {
                     return task;
                 }
             }
+            result @ CmdResult::PlaceBlockOrientationParameter { .. } => {
+                return self.handle_place_block_orientation_parameter(result);
+            }
             result @ CmdResult::PlaceBlockDistanceParameter { .. } => {
                 return self.handle_place_block_distance_parameter(result);
             }

src/app/commands/bvisibility.rs

@@ -7,6 +7,66 @@ use codec::{CadDocument, EntityType, Handle};
 use iced::Task;
 
 impl OpenCADStudio {
+    pub(in crate::app) fn handle_place_block_orientation_parameter(
+        &mut self,
+        result: crate::command::CmdResult,
+    ) -> Task<Message> {
+        let crate::command::CmdResult::PlaceBlockOrientationParameter {
+            document_id,
+            definition,
+            kind,
+            base,
+            end,
+            reference,
+        } = result
+        else {
+            unreachable!()
+        };
+        let i = self.active_tab;
+        if self.tabs[i].id != document_id
+            || self.tabs[i]
+                .active_block_edit_session()
+                .map(|s| s.br_handle)
+                != Some(definition)
+        {
+            self.command_line.push_error(
+                crate::t!("The parameter's Block Editor session is no longer active.").as_ref(),
+            );
+            return Task::none();
+        }
+        let vector = |p: glam::DVec3| codec::types::Vector3::new(p.x, p.y, p.z);
+        if let Some(error) = self.parameter_placement_error(kind.name()).or_else(|| {
+            crate::scene::block_orientation_parameter::points_error(
+                kind,
+                vector(base),
+                vector(end),
+                vector(reference),
+            )
+        }) {
+            self.command_line.push_error(crate::t!(error).as_ref());
+            return Task::none();
+        }
+        self.push_undo_snapshot(i, &format!("{} parameter", kind.name()));
+        crate::scene::block_orientation_parameter::create(
+            &mut self.tabs[i].scene.document,
+            definition,
+            kind,
+            vector(base),
+            vector(end),
+            vector(reference),
+        )
+        .expect("validated parameter placement");
+        self.tabs[i].scene.bump_geometry();
+        self.tabs[i].dirty = true;
+        self.tabs[i].active_cmd = None;
+        self.tabs[i].scene.clear_preview_wire();
+        self.finish_pending_history(i);
+        self.refresh_properties();
+        self.command_line
+            .push_output(crate::tf!("{} parameter placed.", crate::t!(kind.name())).as_ref());
+        Task::none()
+    }
+
     pub(in crate::app) fn handle_place_block_distance_parameter(
         &mut self,
         result: crate::command::CmdResult,
@@ -87,10 +147,11 @@ impl OpenCADStudio {
                     session.br_handle,
                 )
             }
+            "ROTATION" | "R" | "ALIGNMENT" | "A" | "FLIP" | "F" => crate::scene::block_orientation_parameter::placement_error(&tab.scene.document, session.br_handle, crate::scene::block_orientation_parameter::Kind::parse(kind).unwrap()),
             "VISIBILITY" | "V" => {
                 visibility::placement_error(&tab.scene.document, session.br_handle)
             }
-            _ => Some("Supported parameter types: Point, Linear, Polar, XY, Visibility."),
+            _ => Some("Supported parameter types: Point, Linear, Polar, XY, Rotation, Alignment, Flip, Visibility."),
         }
     }
 
@@ -333,6 +394,14 @@ impl OpenCADStudio {
                     return Some(Task::none());
                 };
                 let parameter_type = cmd.strip_prefix("BPARAMETER").unwrap().trim();
+                if let Some(kind) =
+                    crate::scene::block_orientation_parameter::Kind::parse(parameter_type)
+                {
+                    let command = crate::modules::block_editor::orientation_parameter::OrientationParameterCommand::new(self.tabs[i].id,block,kind);
+                    self.command_line.push_info(&command.prompt());
+                    self.tabs[i].active_cmd = Some(Box::new(command));
+                    return Some(Task::none());
+                }
                 if let Some(kind) =
                     crate::scene::block_distance_parameter::Kind::parse(parameter_type)
                 {
@@ -359,7 +428,7 @@ impl OpenCADStudio {
                 {
                     self.command_line.push_error(
                         crate::t!(
-                            "Supported parameter types: Point, Linear, Polar, XY, Visibility."
+                            "Supported parameter types: Point, Linear, Polar, XY, Rotation, Alignment, Flip, Visibility."
                         )
                         .as_ref(),
                     );

src/app/dock/tests.rs

@@ -863,6 +863,54 @@ fn distance_parameter_batch_starts_from_actual_palette_rows() {
     });
 }
 
+#[test]
+fn orientation_parameter_batch_starts_from_actual_palette_rows() {
+    with_stack(|| {
+        for (id, name, inputs) in [
+            (
+                "authoring-tool-rotation",
+                "rotation",
+                vec!["0.35,-0.12", "0.65,-0.12", "0.35,0.2"],
+            ),
+            (
+                "authoring-tool-alignment",
+                "alignment",
+                vec!["0.25,-0.1", "0.6,0.15"],
+            ),
+            (
+                "authoring-tool-flip",
+                "flip",
+                vec!["0.35,-0.15", "0.35,0.15", "0.6,0.15"],
+            ),
+        ] {
+            let mut app = authoring_app();
+            let _ = app.dispatch_command("BAUTHORPALETTE");
+            let point = authoring_control(&app, id);
+            authoring_click(&mut app, point);
+            let i = app.active_tab;
+            let before = app.tabs[i].scene.document.clone();
+            for text in &inputs[..inputs.len() - 1] {
+                let _ = app.update(Message::CommandInput((*text).into()));
+                let _ = app.update(Message::CommandSubmit);
+                assert_eq!(app.tabs[i].scene.document, before);
+            }
+            let _ = app.update(Message::CommandInput(inputs.last().unwrap().to_string()));
+            let _ = app.update(Message::CommandSubmit);
+            let definition = app.tabs[i].active_block_edit_session().unwrap().br_handle;
+            let found = crate::scene::block_orientation_parameter::parameters(
+                &app.tabs[i].scene.document,
+                definition,
+            );
+            assert_eq!(found.len(), 1);
+            assert!(found[0].kind.name().eq_ignore_ascii_case(name));
+            assert!(app.tabs[i].scene.preview_wires.is_empty());
+            assert_eq!(app.tabs[i].history.undo_stack.len(), 1);
+            let _ = app.run_command_line("ZOOM E");
+            authoring_capture(&app, &format!("{name}-parameter-placed"));
+        }
+    });
+}
+
 fn authoring_app() -> OpenCADStudio {
     use codec::{
         entities::{Insert, Line},

src/app/dock/view.rs

@@ -408,6 +408,7 @@ impl OpenCADStudio {
                     chrome,
                     self.visibility_placement_error(),
                     self.point_parameter_placement_error(),
+                    self.parameter_placement_error("FLIP"),
                 )
             }
             crate::ui::dock::PanelId::BlockPalette => {

src/app/view/mod.rs

@@ -1083,7 +1083,26 @@ bg={bg_ms:.1}ms n={view_count}"
                         session.br_handle,
                     )
                     .iter()
-                    .filter_map(|parameter| {
+                    .map(|p| {
+                        (
+                            crate::scene::block_distance_parameter::graphic(p),
+                            p.native.definition_base_point,
+                        )
+                    })
+                    .chain(
+                        crate::scene::block_orientation_parameter::parameters(
+                            &tab.scene.document,
+                            session.br_handle,
+                        )
+                        .iter()
+                        .map(|p| {
+                            (
+                                crate::scene::block_orientation_parameter::graphic(p),
+                                crate::scene::block_orientation_parameter::marker_tail(p),
+                            )
+                        }),
+                    )
+                    .filter_map(|(graphic, marker_tail)| {
                         let project = |p: codec::types::Vector3| {
                             let p = tab
                                 .scene
@@ -1093,7 +1112,6 @@ bg={bg_ms:.1}ms n={view_count}"
                             (p.x.is_finite() && p.y.is_finite())
                                 .then_some(iced::Point::new(vp_bounds.x + p.x, vp_bounds.y + p.y))
                         };
-                        let graphic = crate::scene::block_distance_parameter::graphic(parameter);
                         let lines = graphic
                             .lines
                             .into_iter()
@@ -1111,7 +1129,7 @@ bg={bg_ms:.1}ms n={view_count}"
                                 Some((
                                     project(point)?,
                                     if oriented {
-                                        Some(project(parameter.native.definition_base_point)?)
+                                        Some(project(marker_tail)?)
                                     } else {
                                         None
                                     },
@@ -1120,6 +1138,11 @@ bg={bg_ms:.1}ms n={view_count}"
                             .collect::<Option<Vec<_>>>()?;
                         Some(crate::ui::overlay::AuthoringDimension {
                             lines,
+                            round_grips: graphic
+                                .round_grips
+                                .into_iter()
+                                .map(project)
+                                .collect::<Option<Vec<_>>>()?,
                             dimensions: graphic
                                 .dimensions
                                 .into_iter()

src/command.rs

@@ -1514,6 +1514,15 @@ impl DimensionPreview {
 /// Returned by every `CadCommand` method to tell main.rs what to do.
 #[allow(dead_code)]
 pub enum CmdResult {
+    /// Place a native Rotation, Alignment or Flip parameter.
+    PlaceBlockOrientationParameter {
+        document_id: u64,
+        definition: Handle,
+        kind: crate::scene::block_orientation_parameter::Kind,
+        base: DVec3,
+        end: DVec3,
+        reference: DVec3,
+    },
     /// Place a native two-point parameter after its base, end and label picks.
     PlaceBlockDistanceParameter {
         document_id: u64,

src/modules/block_editor/mod.rs

@@ -8,6 +8,7 @@ use crate::modules::{CadModule, IconKind, ModuleEvent, RibbonGroup, RibbonItem,
 pub mod visibility_parameter;
 pub mod point_parameter;
 pub mod distance_parameter;
+pub mod orientation_parameter;
 
 pub struct BlockEditorModule;
 

src/modules/block_editor/orientation_parameter.rs

@@ -0,0 +1,193 @@
+//! Interactive native Rotation, Alignment and Flip placement.
+use crate::command::{CadCommand, CmdResult};
+use crate::scene::{
+    block_orientation_parameter::{self, Kind},
+    WireModel,
+};
+use codec::{types::Vector3, Handle};
+use glam::DVec3;
+
+pub struct OrientationParameterCommand {
+    document_id: u64,
+    definition: Handle,
+    kind: Kind,
+    base: Option<DVec3>,
+    second: Option<DVec3>,
+}
+
+impl OrientationParameterCommand {
+    pub(crate) fn new(document_id: u64, definition: Handle, kind: Kind) -> Self {
+        Self {
+            document_id,
+            definition,
+            kind,
+            base: None,
+            second: None,
+        }
+    }
+    fn finish(&self, end: DVec3, reference: DVec3) -> CmdResult {
+        let base = self.base.unwrap();
+        let vector = |p: DVec3| Vector3::new(p.x, p.y, p.z);
+        if let Some(error) = block_orientation_parameter::points_error(
+            self.kind,
+            vector(base),
+            vector(end),
+            vector(reference),
+        ) {
+            return CmdResult::ReportError(crate::t!(error).into_owned());
+        }
+        CmdResult::PlaceBlockOrientationParameter {
+            document_id: self.document_id,
+            definition: self.definition,
+            kind: self.kind,
+            base,
+            end,
+            reference,
+        }
+    }
+    fn rotation_at(&self, angle: f64) -> CmdResult {
+        let base = self.base.unwrap();
+        let reference = self.second.unwrap();
+        let radius = (reference - base).length();
+        self.finish(
+            base + DVec3::new(angle.cos(), angle.sin(), 0.0) * radius,
+            reference,
+        )
+    }
+}
+
+impl CadCommand for OrientationParameterCommand {
+    fn name(&self) -> &'static str {
+        "BPARAMETER"
+    }
+    fn prompt(&self) -> String {
+        let step = if self.base.is_none() {
+            "Specify parameter base point:"
+        } else {
+            match (self.kind, self.second.is_some()) {
+                (Kind::Rotation, false) => "Specify parameter radius or pick a radius point:",
+                (Kind::Rotation, true) => "Specify default rotation angle or pick direction <0>:",
+                (Kind::Alignment, _) => "Specify alignment direction (tangent):",
+                (Kind::Flip, false) => "Specify reflection line endpoint:",
+                (Kind::Flip, true) => "Specify flip parameter label location:",
+            }
+        };
+        crate::tf!(
+            "BPARAMETER {}  {}",
+            crate::t!(self.kind.name()),
+            crate::t!(step)
+        )
+        .into_owned()
+    }
+    fn on_point(&mut self, point: DVec3) -> CmdResult {
+        if !point.is_finite() {
+            return CmdResult::ReportError(
+                crate::t!("Specify a finite parameter location.").into_owned(),
+            );
+        }
+        let Some(base) = self.base else {
+            self.base = Some(point);
+            return CmdResult::NeedPoint;
+        };
+        if (point.z - base.z).abs() > 1e-8 {
+            return CmdResult::ReportError(
+                crate::t!("Specify points in the same block XY plane.").into_owned(),
+            );
+        }
+        if self.kind == Kind::Flip && self.second.is_some() {
+            return self.finish(self.second.unwrap(), point);
+        }
+        let d = point - base;
+        let radius = d.x.hypot(d.y);
+        if radius <= 1e-10 || !radius.is_finite() || !d.length().is_finite() {
+            return CmdResult::ReportError(
+                crate::t!("Specify a finite nonzero parameter direction or radius.").into_owned(),
+            );
+        }
+        match self.kind {
+            Kind::Alignment => self.finish(point, point),
+            Kind::Flip => {
+                self.second = Some(point);
+                CmdResult::NeedPoint
+            }
+            Kind::Rotation => {
+                if self.second.is_some() {
+                    self.rotation_at(d.y.atan2(d.x))
+                } else {
+                    self.second = Some(base + DVec3::X * radius);
+                    CmdResult::NeedPoint
+                }
+            }
+        }
+    }
+    fn on_text_input(&mut self, text: &str) -> Option<CmdResult> {
+        if self.kind != Kind::Rotation || self.base.is_none() {
+            return None;
+        }
+        let value = text.trim().parse::<f64>().ok()?;
+        if !value.is_finite() {
+            return Some(CmdResult::ReportError(
+                crate::t!("Specify a finite radius or angle.").into_owned(),
+            ));
+        }
+        Some(if self.second.is_some() {
+            self.rotation_at(value.rem_euclid(360.0).to_radians())
+        } else if value > 1e-10 {
+            self.on_point(self.base.unwrap() + DVec3::X * value)
+        } else {
+            CmdResult::ReportError(crate::t!("Specify a positive parameter radius.").into_owned())
+        })
+    }
+    fn on_preview_wires(&mut self, point: DVec3) -> Vec<WireModel> {
+        let Some(base) = self.base.filter(|_| point.is_finite()) else {
+            return vec![];
+        };
+        let mut lines = vec![];
+        if self.kind == Kind::Rotation {
+            let radius = self
+                .second
+                .map(|p| (p - base).length())
+                .unwrap_or((point - base).length());
+            if !radius.is_finite() {
+                return vec![];
+            }
+            let angle = (point.y - base.y).atan2(point.x - base.x);
+            let end = base + DVec3::new(angle.cos(), angle.sin(), 0.0) * radius;
+            lines.push(vec![base.to_array(), end.to_array()]);
+            lines.push(
+                (0..=64)
+                    .map(|i| {
+                        let a = std::f64::consts::TAU * i as f64 / 64.0;
+                        (base + DVec3::new(a.cos(), a.sin(), 0.0) * radius).to_array()
+                    })
+                    .collect(),
+            );
+        } else {
+            lines.push(vec![
+                base.to_array(),
+                self.second.unwrap_or(point).to_array(),
+            ]);
+            if let Some(end) = self.second {
+                lines.push(vec![end.to_array(), point.to_array()]);
+            }
+        }
+        lines
+            .into_iter()
+            .map(|points| {
+                WireModel::solid_f64(
+                    "preview_orientation_parameter".into(),
+                    points,
+                    WireModel::CYAN,
+                    false,
+                )
+            })
+            .collect()
+    }
+    fn on_enter(&mut self) -> CmdResult {
+        if self.kind == Kind::Rotation && self.second.is_some() {
+            self.rotation_at(0.0)
+        } else {
+            CmdResult::Cancel
+        }
+    }
+}

src/modules/block_editor/visibility_parameter.rs

@@ -28,7 +28,7 @@ impl CadCommand for VisibilityParameterCommand {
     fn prompt(&self) -> String {
         if self.choosing_type {
             crate::t!(
-                "BPARAMETER  Enter parameter type [Point/Linear/Polar/XY/Visibility] <Visibility>:"
+                "BPARAMETER  Enter parameter type [Point/Linear/Polar/XY/Rotation/Alignment/Flip/Visibility] <Visibility>:"
             )
             .into_owned()
         } else {
@@ -43,6 +43,9 @@ impl CadCommand for VisibilityParameterCommand {
                 CmdOption::new(crate::t!("Linear").as_ref(), "L"),
                 CmdOption::new(crate::t!("Polar").as_ref(), "PO"),
                 CmdOption::new(crate::t!("XY").as_ref(), "XY"),
+                CmdOption::new(crate::t!("Rotation").as_ref(), "R"),
+                CmdOption::new(crate::t!("Alignment").as_ref(), "A"),
+                CmdOption::new(crate::t!("Flip").as_ref(), "F"),
                 CmdOption::new(crate::t!("Visibility").as_ref(), "V"),
             ]
         } else {
@@ -68,13 +71,16 @@ impl CadCommand for VisibilityParameterCommand {
                 "L" | "LINEAR" => CmdResult::Dispatch("BPARAMETER LINEAR".into()),
                 "PO" | "POLAR" => CmdResult::Dispatch("BPARAMETER POLAR".into()),
                 "XY" => CmdResult::Dispatch("BPARAMETER XY".into()),
+                "R" | "ROTATION" => CmdResult::Dispatch("BPARAMETER ROTATION".into()),
+                "A" | "ALIGNMENT" => CmdResult::Dispatch("BPARAMETER ALIGNMENT".into()),
+                "F" | "FLIP" => CmdResult::Dispatch("BPARAMETER FLIP".into()),
                 "P" | "POINT" => CmdResult::Dispatch("BPARAMETER POINT".into()),
                 "" | "V" | "VISIBILITY" => {
                     self.choosing_type = false;
                     CmdResult::NeedPoint
                 }
                 _ => CmdResult::ReportError(
-                    crate::t!("Supported parameter types: Point, Linear, Polar, XY, Visibility.")
+                    crate::t!("Supported parameter types: Point, Linear, Polar, XY, Rotation, Alignment, Flip, Visibility.")
                         .into_owned(),
                 ),
             },

src/scene/block_authoring.rs

@@ -183,6 +183,30 @@ pub(super) fn prepare(
     Ok((handle, slots(None)?))
 }
 
+/// Preflight the larger subgraph needed by parameters with state expressions.
+pub(super) fn capacity(
+    document: &CadDocument,
+    definition: Handle,
+    nodes: i32,
+    edges: i32,
+) -> Result<(), &'static str> {
+    let graph = graph(document, definition)?.and_then(|handle| match &document.objects[&handle] {
+        ObjectType::DynamicBlock(object) => match &object.data {
+            DynamicBlockData::EvaluationGraph(graph) => Some(graph),
+            _ => None,
+        },
+        _ => None,
+    });
+    let start = slots(graph)?;
+    if start.node.checked_add(nodes - 1).is_none()
+        || start.eval.checked_add(nodes - 1).is_none()
+        || start.edge.checked_add(edges - 1).is_none()
+    {
+        return Err("The block authoring graph has no free node IDs.");
+    }
+    Ok(())
+}
+
 /// A parameter, its single grip and two position expressions. Supports one-point
 /// parameters and two-point parameters configured with one end grip.
 /// Graph node IDs, expression IDs and edge IDs are separate namespaces.
@@ -191,6 +215,18 @@ pub(super) fn append(
     handle: Handle,
     slots: Slots,
     expressions: [Handle; 4],
+) {
+    append_components(document, handle, slots, &expressions, &[2, 3]);
+}
+
+/// Append a parameter and grip, followed by its location/state expressions.
+/// `components` gives the expression offsets in native dependency order.
+pub(super) fn append_components(
+    document: &mut CadDocument,
+    handle: Handle,
+    slots: Slots,
+    expressions: &[Handle],
+    components: &[usize],
 ) {
     use codec::objects::{BlockEvaluationEdge, BlockEvaluationNode};
     let ObjectType::DynamicBlock(object) = document.objects.get_mut(&handle).unwrap() else {
@@ -201,13 +237,14 @@ pub(super) fn append(
     };
     let n = slots.node;
     let e = slots.edge;
-    let links = [
+    let mut links = vec![[-1; 4]; expressions.len()];
-        [e, e, e + 1, e + 2],
+    links[0] = [e, e, e + 1, e + components.len() as i32];
-        [-1, -1, e, e],
+    links[1] = [-1, -1, e, e];
-        [e + 1, e + 1, -1, -1],
+    for (index, component) in components.iter().enumerate() {
-        [e + 2, e + 2, -1, -1],
+        let edge = e + 1 + index as i32;
-    ];
+        links[*component] = [edge, edge, -1, -1];
-    for (offset, expression) in expressions.into_iter().enumerate() {
+    }
+    for (offset, expression) in expressions.iter().copied().enumerate() {
         graph.nodes.push(BlockEvaluationNode {
             id: n + offset as i32,
             edge_flags: 32,
@@ -217,11 +254,24 @@ pub(super) fn append(
             active_cycles: None,
         });
     }
-    for (offset, source_node, destination_node, outgoing_edges) in [
+    let dependencies = std::iter::once((0, n + 1, n, [-1; 5])).chain(
-        (0, n + 1, n, [-1; 5]),
+        components.iter().enumerate().map(|(index, component)| {
-        (1, n, n + 2, [-1, -1, -1, e + 2, -1]),
+            let offset = index as i32 + 1;
-        (2, n, n + 3, [-1, -1, e + 1, -1, -1]),
+            let previous = if index == 0 { -1 } else { e + offset - 1 };
-    ] {
+            let next = if index + 1 == components.len() {
+                -1
+            } else {
+                e + offset + 1
+            };
+            (
+                offset,
+                n,
+                n + *component as i32,
+                [-1, -1, previous, next, -1],
+            )
+        }),
+    );
+    for (offset, source_node, destination_node, outgoing_edges) in dependencies {
         graph.edges.push(BlockEvaluationEdge {
             id: e + offset,
             next_id: 0,
@@ -231,7 +281,7 @@ pub(super) fn append(
             outgoing_edges,
         });
     }
-    graph.first_node_id = slots.eval + 3;
+    graph.first_node_id = slots.eval + (expressions.len() as i32 - 1);
     graph.first_node_id_copy = graph.first_node_id;
 }
 

src/scene/block_distance_parameter.rs

@@ -176,10 +176,15 @@ pub(crate) fn create(
     if let Some(error) = points_error(kind, base, end, label) {
         return Err(error);
     }
-    let names = parameters(document, definition)
+    let mut names = parameters(document, definition)
         .into_iter()
         .flat_map(|p| p.labels)
         .collect::<Vec<_>>();
+    names.extend(
+        super::block_orientation_parameter::parameters(document, definition)
+            .into_iter()
+            .map(|p| p.label),
+    );
     let unique = |prefix: &str| {
         (1..)
             .map(|n| format!("{prefix}{n}"))
@@ -329,6 +334,7 @@ pub(crate) fn create(
 #[derive(Default)]
 pub(crate) struct Graphic {
     pub lines: Vec<[Vector3; 2]>,
+    pub round_grips: Vec<Vector3>,
     pub dimensions: Vec<[Vector3; 2]>,
     pub labels: Vec<(Vector3, String)>,
     pub grips: Vec<(Vector3, bool)>, // Linear uses a direction arrow; others a square.

src/scene/block_orientation_parameter.rs

@@ -0,0 +1,528 @@
+//! Native Rotation, Alignment and Flip parameter placement.
+use super::block_authoring::{self as authoring, *};
+use super::block_distance_parameter::Graphic;
+use codec::objects::{
+    BlockAlignmentParameter, BlockConnection, BlockElement, BlockEvalValue, BlockFlipGrip,
+    BlockFlipParameter, BlockGrip, BlockGripExpression, BlockOrientedGrip, BlockParameter,
+    BlockParameterProperty, BlockParameterValueSet, BlockRotationParameter, BlockTwoPointParameter,
+    DynamicBlockData, ObjectType,
+};
+use codec::types::{Transform, Vector3};
+use codec::{CadDocument, Handle};
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Kind {
+    Rotation,
+    Alignment,
+    Flip,
+}
+
+impl Kind {
+    pub(crate) fn parse(text: &str) -> Option<Self> {
+        match text.to_ascii_uppercase().as_str() {
+            "ROTATION" | "R" => Some(Self::Rotation),
+            "ALIGNMENT" | "A" => Some(Self::Alignment),
+            "FLIP" | "F" => Some(Self::Flip),
+            _ => None,
+        }
+    }
+    pub(crate) fn name(self) -> &'static str {
+        match self {
+            Self::Rotation => "Rotation",
+            Self::Alignment => "Alignment",
+            Self::Flip => "Flip",
+        }
+    }
+    fn classes(self) -> (&'static str, &'static str, &'static str, &'static str) {
+        match self {
+            Self::Rotation => (
+                "BLOCKROTATIONPARAMETER",
+                "AcDbBlockRotationParameter",
+                "BLOCKROTATIONGRIP",
+                "AcDbBlockRotationGrip",
+            ),
+            Self::Alignment => (
+                "BLOCKALIGNMENTPARAMETER",
+                "AcDbBlockAlignmentParameter",
+                "BLOCKALIGNMENTGRIP",
+                "AcDbBlockAlignmentGrip",
+            ),
+            Self::Flip => (
+                "BLOCKFLIPPARAMETER",
+                "AcDbBlockFlipParameter",
+                "BLOCKFLIPGRIP",
+                "AcDbBlockFlipGrip",
+            ),
+        }
+    }
+}
+
+pub(crate) struct Parameter<'a> {
+    pub handle: Handle,
+    pub kind: Kind,
+    pub native: &'a BlockTwoPointParameter,
+    pub reference: Vector3,
+    pub label: String,
+    pub offset: f64,
+}
+
+fn graph_handle(document: &CadDocument, definition: Handle) -> Option<Handle> {
+    match document
+        .objects
+        .get(&document.extension_dictionary_handle(definition)?)?
+    {
+        ObjectType::Dictionary(dictionary) => dictionary.get("ACAD_ENHANCEDBLOCK"),
+        _ => None,
+    }
+}
+
+pub(crate) fn parameters(document: &CadDocument, definition: Handle) -> Vec<Parameter<'_>> {
+    let Some(graph) = graph_handle(document, definition) else {
+        return vec![];
+    };
+    let Some(ObjectType::DynamicBlock(object)) = document.objects.get(&graph) else {
+        return vec![];
+    };
+    let DynamicBlockData::EvaluationGraph(data) = &object.data else {
+        return vec![];
+    };
+    data.nodes
+        .iter()
+        .filter_map(|node| {
+            let ObjectType::DynamicBlock(object) = document.objects.get(&node.expression)? else {
+                return None;
+            };
+            if object.owner != graph {
+                return None;
+            }
+            let (kind, native, reference, label, offset) = match &object.data {
+                DynamicBlockData::RotationParameter(p) => (
+                    Kind::Rotation,
+                    &p.parameter,
+                    p.definition_base_angle_point,
+                    p.angle_name.clone(),
+                    p.angle,
+                ),
+                DynamicBlockData::AlignmentParameter(p) => (
+                    Kind::Alignment,
+                    &p.parameter,
+                    p.parameter.definition_end_point,
+                    p.parameter.parameter.element.name.clone(),
+                    0.0,
+                ),
+                DynamicBlockData::FlipParameter(p) => (
+                    Kind::Flip,
+                    &p.parameter,
+                    p.definition_label_point,
+                    p.flip_label.clone(),
+                    0.0,
+                ),
+                _ => return None,
+            };
+            Some(Parameter {
+                handle: object.handle,
+                kind,
+                native,
+                reference,
+                label,
+                offset,
+            })
+        })
+        .collect()
+}
+
+pub(crate) fn placement_error(
+    document: &CadDocument,
+    definition: Handle,
+    kind: Kind,
+) -> Option<&'static str> {
+    let nodes = if kind == Kind::Flip { 5 } else { 4 };
+    authoring::capacity(document, definition, nodes, nodes - 1).err()
+}
+
+pub(crate) fn points_error(
+    kind: Kind,
+    base: Vector3,
+    end: Vector3,
+    reference: Vector3,
+) -> Option<&'static str> {
+    if ![base, end, reference]
+        .iter()
+        .all(|p| [p.x, p.y, p.z].iter().all(|v| v.is_finite()))
+    {
+        return Some("Specify finite parameter locations.");
+    }
+    let d = end - base;
+    let length = d.x.hypot(d.y);
+    if !length.is_finite() {
+        return Some("The parameter dimensions are too large.");
+    }
+    if length <= 1e-10 || (end.z - base.z).abs() > 1e-8 || (reference.z - base.z).abs() > 1e-8 {
+        return Some("Specify distinct parameter points in the same block XY plane.");
+    }
+    if kind == Kind::Rotation {
+        let r = reference - base;
+        if !r.length().is_finite() || !d.length().is_finite() {
+            return Some("The parameter dimensions are too large.");
+        }
+        if !r.x.hypot(r.y).is_finite() || (r.x.hypot(r.y) - length).abs() > length.max(1.0) * 1e-8 {
+            return Some("The rotation grip and base-angle point must share the specified radius.");
+        }
+    }
+    None
+}
+
+pub(crate) fn create(
+    document: &mut CadDocument,
+    definition: Handle,
+    kind: Kind,
+    base: Vector3,
+    end: Vector3,
+    reference: Vector3,
+) -> Result<Handle, &'static str> {
+    if let Some(error) = points_error(kind, base, end, reference)
+        .or_else(|| placement_error(document, definition, kind))
+    {
+        return Err(error);
+    }
+    let mut names = super::block_distance_parameter::parameters(document, definition)
+        .into_iter()
+        .flat_map(|p| p.labels)
+        .collect::<Vec<_>>();
+    names.extend(
+        parameters(document, definition)
+            .into_iter()
+            .map(|p| p.label),
+    );
+    let prefix = match kind {
+        Kind::Rotation => "Angle",
+        Kind::Alignment => "Alignment",
+        Kind::Flip => "Flip state",
+    };
+    let label = (1..)
+        .map(|n| format!("{prefix}{n}"))
+        .find(|name| names.iter().all(|old| !old.eq_ignore_ascii_case(name)))
+        .unwrap();
+    let (graph, slots) = authoring::prepare(document, definition)?;
+    let (class, cpp, grip_class, grip_cpp) = kind.classes();
+    register_classes(
+        document,
+        &[
+            (class, cpp, 55),
+            (grip_class, grip_cpp, 55),
+            ("BLOCKGRIPLOCATIONCOMPONENT", "AcDbBlockGripExpr", 20),
+        ],
+    );
+    let count = if kind == Kind::Flip { 5 } else { 4 };
+    let handles = (0..count)
+        .map(|_| document.allocate_handle())
+        .collect::<Vec<_>>();
+    let element = |offset, name: &str| BlockElement {
+        eval: expression(slots.eval + offset, NO_VALUE, BlockEvalValue::None),
+        name: name.into(),
+        major: MAJOR,
+        minor: MINOR,
+        eed_1071: 0,
+    };
+    let native = BlockTwoPointParameter {
+        parameter: BlockParameter {
+            element: element(
+                0,
+                if kind == Kind::Alignment {
+                    &label
+                } else {
+                    kind.name()
+                },
+            ),
+            show_properties: true,
+            chain_actions: false,
+        },
+        definition_base_point: base,
+        definition_end_point: end,
+        properties: std::array::from_fn(|i| BlockParameterProperty {
+            connections: if kind == Kind::Rotation && i >= 2 {
+                vec![BlockConnection {
+                    code: slots.eval + 1,
+                    name: if i == 2 {
+                        "DisplacementX"
+                    } else {
+                        "DisplacementY"
+                    }
+                    .into(),
+                }]
+            } else {
+                vec![]
+            },
+        }),
+        property_states: if kind == Kind::Rotation {
+            [0, slots.eval + 1, 0, 0]
+        } else {
+            [slots.eval + 1, 0, 0, 0]
+        },
+        ..Default::default()
+    };
+    let data = match kind {
+        Kind::Rotation => DynamicBlockData::RotationParameter(BlockRotationParameter {
+            parameter: native,
+            definition_base_angle_point: reference,
+            angle_name: label,
+            angle: (end - base).length() * 0.15,
+            value_set: BlockParameterValueSet {
+                flags: 3,
+                maximum: std::f64::consts::TAU,
+                ..Default::default()
+            },
+            ..Default::default()
+        }),
+        Kind::Alignment => DynamicBlockData::AlignmentParameter(BlockAlignmentParameter {
+            parameter: native,
+            align_perpendicular: false,
+        }),
+        Kind::Flip => DynamicBlockData::FlipParameter(BlockFlipParameter {
+            parameter: native,
+            flip_label: label,
+            base_state_label: "Not flipped".into(),
+            flipped_state_label: "Flipped".into(),
+            definition_label_point: reference,
+            flags_96: slots.eval + 1,
+            tooltip: "UpdatedFlip".into(),
+            ..Default::default()
+        }),
+    };
+    document.objects.insert(
+        handles[0],
+        ObjectType::DynamicBlock(dynamic(handles[0], graph, class, cpp, data)),
+    );
+    let x_offset = if kind == Kind::Flip { 3 } else { 2 };
+    let grip = BlockGrip {
+        element: element(1, "Grip"),
+        flags_91: slots.eval + x_offset,
+        flags_92: slots.eval + x_offset + 1,
+        location: if kind == Kind::Rotation { end } else { base },
+        insert_cycling: kind == Kind::Alignment,
+        insert_cycling_weight: -1,
+    };
+    let data = match kind {
+        Kind::Rotation => DynamicBlockData::RotationGrip(grip),
+        Kind::Alignment => DynamicBlockData::AlignmentGrip(BlockOrientedGrip {
+            grip,
+            orientation: end - base,
+        }),
+        Kind::Flip => DynamicBlockData::FlipGrip(BlockFlipGrip {
+            grip,
+            combined_state: slots.eval + 2,
+            orientation: end - base,
+        }),
+    };
+    document.objects.insert(
+        handles[1],
+        ObjectType::DynamicBlock(dynamic(handles[1], graph, grip_class, grip_cpp, data)),
+    );
+    for (offset, axis, code, value) in [
+        (
+            x_offset,
+            if kind == Kind::Rotation {
+                "UpdatedEndX"
+            } else {
+                "UpdatedBaseX"
+            },
+            40,
+            BlockEvalValue::Real(0.0),
+        ),
+        (
+            x_offset + 1,
+            if kind == Kind::Rotation {
+                "UpdatedEndY"
+            } else {
+                "UpdatedBaseY"
+            },
+            40,
+            BlockEvalValue::Real(0.0),
+        ),
+    ]
+    .into_iter()
+    .chain((kind == Kind::Flip).then_some((2, "UpdatedFlip", 70, BlockEvalValue::Short(0))))
+    {
+        let handle = handles[offset as usize];
+        document.objects.insert(
+            handle,
+            ObjectType::DynamicBlock(dynamic(
+                handle,
+                graph,
+                "BLOCKGRIPLOCATIONCOMPONENT",
+                "AcDbBlockGripExpr",
+                DynamicBlockData::GripLocationComponent(BlockGripExpression {
+                    eval: expression(slots.eval + offset, code, value),
+                    grip_type: slots.eval,
+                    expression: axis.into(),
+                }),
+            )),
+        );
+    }
+    let components: &[usize] = if kind == Kind::Flip {
+        &[3, 4, 2]
+    } else {
+        &[2, 3]
+    };
+    authoring::append_components(document, graph, slots, &handles, components);
+    Ok(handles[0])
+}
+
+pub(crate) fn graphic(parameter: &Parameter<'_>) -> Graphic {
+    let base = parameter.native.definition_base_point;
+    let end = parameter.native.definition_end_point;
+    let d = end - base;
+    let radius = d.x.hypot(d.y).hypot(d.z);
+    let mut result = Graphic::default();
+    if !radius.is_finite() || radius <= 1e-10 {
+        return result;
+    }
+    match parameter.kind {
+        Kind::Rotation => {
+            let reference = parameter.reference - base;
+            let u = reference.normalize();
+            let mut v = if u.z.abs() < 1e-10 && d.z.abs() < 1e-10 {
+                Vector3::new(-u.y, u.x, 0.0)
+            } else {
+                d - u * d.dot(&u)
+            };
+            if v.length() <= 1e-10 {
+                v = Vector3::new(-u.y, u.x, 0.0);
+            }
+            if v.length() <= 1e-10 {
+                v = Vector3::UNIT_Y;
+            }
+            let v = v.normalize();
+            let mut angle = d.dot(&v).atan2(d.dot(&u)).rem_euclid(std::f64::consts::TAU);
+            if angle.abs() <= 1e-10 {
+                angle = std::f64::consts::TAU;
+            }
+            let at = |angle: f64, r: f64| base + (u * angle.cos() + v * angle.sin()) * r;
+            result
+                .lines
+                .extend([[base, parameter.reference], [base, end]]);
+            for step in 0..48 {
+                result.lines.push([
+                    at(angle * step as f64 / 48.0, radius),
+                    at(angle * (step + 1) as f64 / 48.0, radius),
+                ]);
+            }
+            result.labels.push((
+                at(angle * 0.5, radius + parameter.offset),
+                parameter.label.clone(),
+            ));
+            result.round_grips.push(end);
+        }
+        Kind::Alignment => {
+            result.lines.push([base, end]);
+            result.labels.push((end, parameter.label.clone()));
+            result.grips.push((base, true));
+        }
+        Kind::Flip => {
+            for step in (0..24).step_by(2) {
+                result.lines.push([
+                    base + d * (step as f64 / 24.0),
+                    base + d * ((step + 1) as f64 / 24.0),
+                ]);
+            }
+            result.lines.push([end, parameter.reference]);
+            result
+                .labels
+                .push((parameter.reference, parameter.label.clone()));
+            result.grips.push((base, true));
+        }
+    }
+    result
+}
+
+/// Tail position used to orient a base grip in the shared screen overlay.
+pub(crate) fn marker_tail(parameter: &Parameter<'_>) -> Vector3 {
+    let base = parameter.native.definition_base_point;
+    let d = parameter.native.definition_end_point - base;
+    if parameter.kind == Kind::Flip {
+        base - Vector3::new(-d.y, d.x, 0.0)
+    } else {
+        base - d
+    }
+}
+
+pub(crate) fn reframe(
+    document: &mut CadDocument,
+    definition: Handle,
+    transform: &Transform,
+) -> usize {
+    let Some(graph) = graph_handle(document, definition) else {
+        return 0;
+    };
+    let owned = parameters(document, definition)
+        .iter()
+        .map(|p| (p.handle, p.native.property_states))
+        .collect::<Vec<_>>();
+    let mut changed = 0;
+    for (handle, ids) in owned {
+        if let Some(ObjectType::DynamicBlock(object)) = document.objects.get_mut(&handle) {
+            let native = match &mut object.data {
+                DynamicBlockData::RotationParameter(p) => {
+                    p.definition_base_angle_point = transform.apply(p.definition_base_angle_point);
+                    &mut p.parameter
+                }
+                DynamicBlockData::AlignmentParameter(p) => &mut p.parameter,
+                DynamicBlockData::FlipParameter(p) => {
+                    p.definition_label_point = transform.apply(p.definition_label_point);
+                    &mut p.parameter
+                }
+                _ => continue,
+            };
+            native.definition_base_point = transform.apply(native.definition_base_point);
+            native.definition_end_point = transform.apply(native.definition_end_point);
+            for point in [
+                &mut native.updated_base_point,
+                &mut native.base_point,
+                &mut native.updated_end_point,
+                &mut native.end_point,
+            ]
+            .into_iter()
+            .flatten()
+            {
+                *point = transform.apply(*point);
+            }
+            changed += 1;
+        }
+        for object in document.objects.values_mut() {
+            let ObjectType::DynamicBlock(object) = object else {
+                continue;
+            };
+            if object.owner != graph {
+                continue;
+            }
+            let grip = match &mut object.data {
+                DynamicBlockData::RotationGrip(g)
+                    if g.element.eval.node_id > 0 && ids.contains(&g.element.eval.node_id) =>
+                {
+                    g
+                }
+                DynamicBlockData::AlignmentGrip(g)
+                    if g.grip.element.eval.node_id > 0
+                        && ids.contains(&g.grip.element.eval.node_id) =>
+                {
+                    g.orientation = transform.apply_rotation(g.orientation);
+                    &mut g.grip
+                }
+                DynamicBlockData::FlipGrip(g)
+                    if g.grip.element.eval.node_id > 0
+                        && ids.contains(&g.grip.element.eval.node_id) =>
+                {
+                    g.orientation = transform.apply_rotation(g.orientation);
+                    &mut g.grip
+                }
+                _ => continue,
+            };
+            grip.location = transform.apply(grip.location);
+            changed += 1;
+        }
+    }
+    changed
+}
+
+#[cfg(test)]
+mod tests;

src/scene/block_orientation_parameter/tests.rs

@@ -0,0 +1,328 @@
+use super::*;
+use crate::scene::{block_distance_parameter, block_point_parameter, block_visibility, Scene};
+use codec::{entities::Line, EntityType};
+
+fn fixture() -> (Scene, Handle) {
+    let mut scene = Scene::new();
+    scene.define_block_raw(
+        "PARAMETERS",
+        Vector3::ZERO,
+        vec![EntityType::Line(Line::from_points(
+            Vector3::ZERO,
+            Vector3::UNIT_X,
+        ))],
+    );
+    let handle = scene
+        .document
+        .block_records
+        .get("PARAMETERS")
+        .unwrap()
+        .handle;
+    (scene, handle)
+}
+fn append_batch(document: &mut CadDocument, definition: Handle) {
+    for kind in [Kind::Rotation, Kind::Alignment, Kind::Flip] {
+        create(
+            document,
+            definition,
+            kind,
+            Vector3::ZERO,
+            Vector3::new(0.0, 2.0, 0.0),
+            if kind == Kind::Rotation {
+                Vector3::new(2.0, 0.0, 0.0)
+            } else {
+                Vector3::new(3.0, 3.0, 0.0)
+            },
+        )
+        .unwrap();
+    }
+}
+fn graph_data(document: &CadDocument, definition: Handle) -> &codec::objects::BlockEvaluationGraph {
+    let ObjectType::DynamicBlock(o) =
+        &document.objects[&graph_handle(document, definition).unwrap()]
+    else {
+        panic!()
+    };
+    let DynamicBlockData::EvaluationGraph(g) = &o.data else {
+        panic!()
+    };
+    g
+}
+fn assert_roundtrips(document: &CadDocument, definition: Handle, before: &CadDocument) {
+    let graph = graph_handle(document, definition).unwrap();
+    if let Some(old_graph) = graph_handle(before, definition) {
+        for (h, o) in &before.objects {
+            if *h != old_graph {
+                assert_eq!(document.objects.get(h), Some(o), "preserved {h}");
+            }
+        }
+        let old = graph_data(before, definition);
+        let new = graph_data(document, definition);
+        assert_eq!(&new.nodes[..old.nodes.len()], &old.nodes);
+        assert_eq!(&new.edges[..old.edges.len()], &old.edges);
+    }
+    let objects = document
+        .objects
+        .iter()
+        .filter_map(|(h, o)| match o {
+            ObjectType::DynamicBlock(o) if o.owner == graph && !before.objects.contains_key(h) => {
+                Some((*h, o.data.clone()))
+            }
+            _ => None,
+        })
+        .collect::<Vec<_>>();
+    assert_eq!(objects.len(), 13);
+    let g = graph_data(document, definition);
+    for node in g
+        .nodes
+        .iter()
+        .filter(|n| objects.iter().any(|(h, _)| *h == n.expression))
+    {
+        let incoming = g
+            .edges
+            .iter()
+            .filter(|e| e.destination_node == node.id)
+            .map(|e| e.id)
+            .collect::<Vec<_>>();
+        let outgoing = g
+            .edges
+            .iter()
+            .filter(|e| e.source_node == node.id)
+            .map(|e| e.id)
+            .collect::<Vec<_>>();
+        assert_eq!(
+            node.node_data,
+            [
+                incoming.first().copied().unwrap_or(-1),
+                incoming.last().copied().unwrap_or(-1),
+                outgoing.first().copied().unwrap_or(-1),
+                outgoing.last().copied().unwrap_or(-1)
+            ]
+        );
+    }
+    for extension in ["dwg", "dxf"] {
+        let bytes = crate::io::save_to_bytes(document, extension, document.version).unwrap();
+        let read = crate::io::load_bytes(&format!("orientation.{extension}"), bytes).unwrap();
+        for (h, data) in &objects {
+            let ObjectType::DynamicBlock(object) = &read.objects[h] else {
+                panic!("{extension}: native {h}")
+            };
+            assert_eq!(&object.data, data, "{extension}: {h}");
+            assert_eq!(object.owner, graph);
+        }
+        assert!(authoring::graph(&read, definition).is_ok());
+    }
+}
+#[test]
+fn orientation_parameter_native_batch_coexists_and_roundtrips_complete_objects() {
+    let (mut scene, definition) = fixture();
+    block_point_parameter::create(
+        &mut scene.document,
+        definition,
+        Vector3::ZERO,
+        Vector3::UNIT_X,
+    )
+    .unwrap();
+    block_visibility::create(&mut scene.document, definition, Vector3::ZERO).unwrap();
+    block_distance_parameter::create(
+        &mut scene.document,
+        definition,
+        block_distance_parameter::Kind::Polar,
+        Vector3::ZERO,
+        Vector3::UNIT_Y,
+        Vector3::UNIT_X,
+    )
+    .unwrap();
+    let before = scene.document.clone();
+    append_batch(&mut scene.document, definition);
+    assert_roundtrips(&scene.document, definition, &before);
+    let parameters = parameters(&scene.document, definition);
+    assert_eq!(parameters[0].label, "Angle2", "share labels with Polar");
+    for p in &parameters {
+        let id = p.native.parameter.element.eval.node_id;
+        assert_eq!(
+            p.native.property_states,
+            if p.kind == Kind::Rotation {
+                [0, id + 1, 0, 0]
+            } else {
+                [id + 1, 0, 0, 0]
+            }
+        );
+    }
+    let flip = parameters.iter().find(|p| p.kind == Kind::Flip).unwrap();
+    let id = flip.native.parameter.element.eval.node_id;
+    assert!(scene.document.objects.values().any(|o|matches!(o,ObjectType::DynamicBlock(o) if matches!(&o.data,DynamicBlockData::FlipGrip(g) if g.combined_state==id+2&&g.grip.flags_91==id+3&&g.grip.flags_92==id+4))));
+    assert!(scene.document.objects.values().any(|o|matches!(o,ObjectType::DynamicBlock(o) if matches!(&o.data,DynamicBlockData::GripLocationComponent(c) if c.expression=="UpdatedFlip"&&c.grip_type==id&&c.eval.value_code==70&&c.eval.value==BlockEvalValue::Short(0)))));
+}
+#[test]
+fn orientation_parameter_rotation_and_polar_share_unique_labels_in_both_orders() {
+    for rotation_first in [false, true] {
+        let (mut scene, definition) = fixture();
+        for rotation in [rotation_first, !rotation_first] {
+            if rotation {
+                create(
+                    &mut scene.document,
+                    definition,
+                    Kind::Rotation,
+                    Vector3::ZERO,
+                    Vector3::UNIT_Y,
+                    Vector3::UNIT_X,
+                )
+                .unwrap();
+            } else {
+                block_distance_parameter::create(
+                    &mut scene.document,
+                    definition,
+                    block_distance_parameter::Kind::Polar,
+                    Vector3::ZERO,
+                    Vector3::UNIT_Y,
+                    Vector3::UNIT_X,
+                )
+                .unwrap();
+            }
+        }
+        let rotation = parameters(&scene.document, definition)[0].label.clone();
+        let polar =
+            block_distance_parameter::parameters(&scene.document, definition)[0].labels[1].clone();
+        assert_ne!(rotation, polar);
+    }
+}
+
+#[test]
+fn orientation_parameter_flip_capacity_and_invalid_points_leave_document_intact() {
+    let (mut scene, definition) = fixture();
+    for kind in [Kind::Rotation, Kind::Alignment, Kind::Flip] {
+        for end in [
+            Vector3::ZERO,
+            Vector3::new(f64::NAN, 1.0, 0.0),
+            Vector3::new(1.0, 1.0, 1.0),
+        ] {
+            let before = scene.document.clone();
+            assert!(create(
+                &mut scene.document,
+                definition,
+                kind,
+                Vector3::ZERO,
+                end,
+                Vector3::UNIT_X
+            )
+            .is_err());
+            assert_eq!(scene.document, before);
+        }
+    }
+    append_batch(&mut scene.document, definition);
+    let graph = graph_handle(&scene.document, definition).unwrap();
+    if let ObjectType::DynamicBlock(o) = scene.document.objects.get_mut(&graph).unwrap() {
+        if let DynamicBlockData::EvaluationGraph(g) = &mut o.data {
+            g.first_node_id = i32::MAX - 4;
+        }
+    }
+    let before = scene.document.clone();
+    assert!(placement_error(&scene.document, definition, Kind::Flip).is_some());
+    assert!(create(
+        &mut scene.document,
+        definition,
+        Kind::Flip,
+        Vector3::ZERO,
+        Vector3::UNIT_X,
+        Vector3::ZERO
+    )
+    .is_err());
+    assert_eq!(scene.document, before);
+    assert!(placement_error(&scene.document, definition, Kind::Rotation).is_none());
+    create(
+        &mut scene.document,
+        definition,
+        Kind::Rotation,
+        Vector3::ZERO,
+        Vector3::UNIT_Y,
+        Vector3::UNIT_X,
+    )
+    .unwrap();
+    assert_eq!(
+        graph_data(&scene.document, definition).first_node_id,
+        i32::MAX
+    );
+}
+#[test]
+fn orientation_parameter_reframe_and_editor_extents_preserve_native_points() {
+    let (mut scene, definition) = fixture();
+    append_batch(&mut scene.document, definition);
+    let original = parameters(&scene.document, definition)
+        .iter()
+        .map(|p| {
+            (
+                p.native.definition_base_point,
+                p.native.definition_end_point,
+                p.reference,
+            )
+        })
+        .collect::<Vec<_>>();
+    let transform = Transform::from_translation(Vector3::new(10.0, 20.0, 0.0));
+    assert_eq!(reframe(&mut scene.document, definition, &transform), 6);
+    for (p, (base, end, reference)) in parameters(&scene.document, definition).iter().zip(original)
+    {
+        assert_eq!(p.native.definition_base_point, transform.apply(base));
+        assert_eq!(p.native.definition_end_point, transform.apply(end));
+        assert_eq!(p.reference, transform.apply(reference));
+        assert!(graphic(p)
+            .lines
+            .into_iter()
+            .flatten()
+            .all(|p| p.x.is_finite() && p.y.is_finite() && p.z.is_finite()));
+    }
+    scene.block_edit_block = Some(definition);
+    let (_, max) = scene.visible_block_bounds(definition).unwrap();
+    assert!(max.x >= 13.0 && max.y >= 23.0);
+    scene.block_edit_block = None;
+    let (_, max) = scene.visible_block_bounds(definition).unwrap();
+    assert!(max.x <= 1.0 && max.y < 1.0);
+}
+#[test]
+fn orientation_parameter_rotation_270_graphic_retains_counterclockwise_arc() {
+    let (mut scene, definition) = fixture();
+    create(
+        &mut scene.document,
+        definition,
+        Kind::Rotation,
+        Vector3::ZERO,
+        -Vector3::UNIT_Y,
+        Vector3::UNIT_X,
+    )
+    .unwrap();
+    let g = graphic(&parameters(&scene.document, definition)[0]);
+    assert!(g.lines.iter().flatten().any(|p| p.x < -0.99));
+}
+#[test]
+#[ignore = "requires OCS_DYNAMIC_BLOCK_FIXTURES with local DWG fixtures"]
+fn orientation_parameter_fixture_batch_roundtrips() {
+    use sha2::{Digest, Sha256};
+    let directory = std::env::var_os("OCS_DYNAMIC_BLOCK_FIXTURES").expect("fixture directory");
+    let mut paths = std::fs::read_dir(directory)
+        .unwrap()
+        .map(|p| p.unwrap().path())
+        .filter(|p| p.extension().is_some_and(|e| e.eq_ignore_ascii_case("dwg")))
+        .collect::<Vec<_>>();
+    paths.sort();
+    assert_eq!(paths.len(), 17);
+    for path in paths {
+        let bytes = std::fs::read(&path).unwrap();
+        let digest = Sha256::digest(&bytes);
+        let filename = path.file_name().unwrap().to_string_lossy();
+        let mut document = crate::io::load_bytes(&filename, bytes).unwrap();
+        let definition = document
+            .block_records
+            .iter()
+            .map(|b| b.handle)
+            .find(|h| {
+                authoring::graph(&document, *h).is_ok_and(|g| g.is_some())
+                    && placement_error(&document, *h, Kind::Flip).is_none()
+            })
+            .unwrap();
+        let before = document.clone();
+        append_batch(&mut document, definition);
+        assert_roundtrips(&document, definition, &before);
+        assert_eq!(Sha256::digest(std::fs::read(&path).unwrap()), digest);
+        eprintln!("{filename}: Rotation/Alignment/Flip native DWG/DXF objects and graph append passed; original graph/objects/checksum preserved");
+    }
+}

src/scene/camera_ops.rs

@@ -1687,6 +1687,22 @@ impl Scene {
                     fold!(Some((point, point)));
                 }
             }
+            for parameter in super::block_orientation_parameter::parameters(&self.document, block) {
+                let graphic = super::block_orientation_parameter::graphic(&parameter);
+                for point in graphic
+                    .lines
+                    .into_iter()
+                    .flatten()
+                    .chain(graphic.labels.into_iter().map(|(p, _)| p))
+                    .chain([
+                        parameter.native.definition_base_point,
+                        parameter.native.definition_end_point,
+                    ])
+                {
+                    let point = glam::DVec3::new(point.x, point.y, point.z);
+                    fold!(Some((point, point)));
+                }
+            }
             if let Some(parameter) = super::block_visibility::parameter(&self.document, block) {
                 let point = parameter.def_point;
                 let point = glam::DVec3::new(point.x, point.y, point.z);

src/scene/mod.rs

@@ -13,6 +13,7 @@ pub mod block_visibility;
 pub(crate) mod block_authoring;
 pub(crate) mod block_point_parameter;
 pub(crate) mod block_distance_parameter;
+pub(crate) mod block_orientation_parameter;
 pub mod cache;
 pub mod compare;
 pub mod convert;

src/scene/modify.rs

@@ -565,6 +565,12 @@ impl Scene {
                 block_record,
                 local_from_old,
             );
+        let parameter_changes = parameter_changes
+            + super::block_orientation_parameter::reframe(
+                &mut self.document,
+                block_record,
+                local_from_old,
+            );
         if !changed.is_empty() || parameter_changes > 0 {
             self.rebuild_derived_caches();
         }

src/ui/overlay.rs

@@ -1019,6 +1019,7 @@ pub(crate) fn selection_overlay<'a>(
 
 pub(crate) struct AuthoringDimension {
     pub lines: Vec<[Point; 2]>,
+    pub round_grips: Vec<Point>,
     pub dimensions: Vec<[Point; 2]>,
     pub labels: Vec<(Point, String)>,
     pub grips: Vec<(Point, Option<Point>)>,
@@ -2410,6 +2411,9 @@ impl canvas::Program<Message> for SelectionCanvas {
                         ..Default::default()
                     });
                 }
+                for point in &dimension.round_grips {
+                    frame.fill(&canvas::Path::circle(*point, 3.5), color);
+                }
                 for (point, base) in &dimension.grips {
                     let marker = if let Some(base) = base {
                         let dx = point.x - base.x;

src/ui/window/authoring_palettes.rs

@@ -192,6 +192,7 @@ fn catalog(
     tab: Tab,
     visibility_error: Option<&'static str>,
     point_error: Option<&'static str>,
+    flip_error: Option<&'static str>,
 ) -> Element<'static, Message> {
     let (entries, unavailable) = match tab {
         Tab::Parameters => (
@@ -209,7 +210,9 @@ fn catalog(
         let visibility = tab == Tab::Parameters && *label == "Visibility";
         let point = tab == Tab::Parameters && *label == "Point";
         let distance = tab == Tab::Parameters && matches!(*label, "Linear" | "Polar" | "XY");
-        let enabled = (visibility && visibility_error.is_none()) || ((point || distance) && point_error.is_none());
+        let orientation = tab == Tab::Parameters && matches!(*label,"Rotation"|"Alignment"|"Flip");
+        let orientation_error = if *label=="Flip" {flip_error} else {point_error};
+        let enabled = (orientation && orientation_error.is_none()) || (visibility && visibility_error.is_none()) || ((point || distance) && point_error.is_none());
         let base = if enabled {
             icons::semantic(icon, 28.0)
         } else {
@@ -244,6 +247,12 @@ fn catalog(
                 .into_owned()
         } else if distance {
             crate::t!(point_error.unwrap_or("Place the base point, endpoint, and dimension label. Creates one end grip; associate an action to change geometry.")).into_owned()
+        } else if orientation {
+            crate::t!(orientation_error.unwrap_or(match *label {
+                "Rotation" => "Place the center, specify a radius, then the default rotation angle.",
+                "Alignment" => "Place the alignment base point and tangent direction.",
+                _ => "Place a reflection line and its flip-state label. Associate a Flip action to mirror geometry.",
+            })).into_owned()
         } else {
             unavailable.to_string()
         };
@@ -254,6 +263,8 @@ fn catalog(
             container(entry).id("authoring-tool-point").into()
         } else if distance {
             container(entry).id(match *label { "Linear" => "authoring-tool-linear", "Polar" => "authoring-tool-polar", _ => "authoring-tool-xy" }).into()
+        } else if orientation {
+            container(entry).id(match *label {"Rotation"=>"authoring-tool-rotation","Alignment"=>"authoring-tool-alignment",_=>"authoring-tool-flip"}).into()
         } else {
             entry
         }
@@ -366,6 +377,7 @@ pub fn view(
     chrome: Chrome,
     visibility_error: Option<&'static str>,
     point_error: Option<&'static str>,
+    flip_error: Option<&'static str>,
 ) -> Element<'static, Message> {
     let tabs = column(Tab::ALL.into_iter().map(|category| {
         let label = category.label();
@@ -415,9 +427,14 @@ pub fn view(
             chrome,
         ),
         row![
-            scrollable(catalog(selected_tab, visibility_error, point_error))
+            scrollable(catalog(
-                .width(Fill)
+                selected_tab,
-                .height(Fill),
+                visibility_error,
+                point_error,
+                flip_error
+            ))
+            .width(Fill)
+            .height(Fill),
             tabs
         ]
         .spacing(4)