Merge pull request #1447 from ramox81:codex/diameter-constraint-parity

#1447 branched from the same commit as #1443 and rewrote the radial
dimensional constraint a second time, so the two designs had to be
reconciled rather than stacked. #1447's is the one kept: it covers
DCRADIUS and DCDIAMETER through one command, places the dimension by the
direction the location was picked in rather than storing a text point,
and names the parameters `radN` / `diaN`. #1443's radial command result,
its entity builder call and its follow-up code are gone; its own
independent work stays — the ribbon's small-button grid and tool
descriptions, the magnitude reading of a negative radius, and the centre
anchor a parameter edit resizes a circle about.

The DIMCONSTRAINT default follows #1443: running DCRADIUS or DCDIAMETER
directly leaves it alone, and the Dispatch arm sets it when DIMCONSTRAINT
is what asked for the command.

The second commit's radial drawing — the dimension line broken around the
text, the elbowed leader, the centre-mark and arrowhead rules — applied to
every radius and diameter dimension, not just a constraint's, and three
layout-parity tests said the old layout was the measured one. It is now
scoped to a dimensional constraint's own dimension, as #1443 scoped its
version, and ordinary radial dimensions draw as they did.

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

src/modules/parametric/dim_constraint.rs

@@ -16,8 +16,10 @@ pub enum DimConstraintAxis {
     Aligned,
     /// The angle between two lines, or at a vertex between two points.
     Angular,
-    /// The radius of a circle or arc.
+    /// A circle's or arc's radius.
     Radius,
+    /// A circle's or arc's diameter.
+    Diameter,
 }
 
 /// A picked line (a line entity or one polyline segment) an Aligned
@@ -108,15 +110,15 @@ enum Step {
         sector: u8,
         measured: f64,
     },
-    /// Radius: `Select arc or circle:`
-    RadialSelect,
-    /// `Specify dimension line location:` of a radius.
-    RadialLocation { circle: ParametricRef, radius: f64 },
-    /// `Enter value or name and value <rad1=30>:`
+    /// Radius/Diameter: `Select arc or circle:`
+    RadialObject,
+    /// `Specify dimension line location:` of a radius or diameter.
+    RadialLocation { target: RadialTarget },
+    /// `Enter value or name and value <dia1=50>:`
     RadialValue {
-        circle: ParametricRef,
-        radius: f64,
+        target: RadialTarget,
         location: DVec3,
+        measured: f64,
     },
     /// `Enter value or name and value <d1=100>:`
     Value {
@@ -147,6 +149,14 @@ enum AngularData {
     },
 }
 
+/// The circle or arc a Radius/Diameter constraint measures.
+#[derive(Clone, Copy)]
+struct RadialTarget {
+    circle: ParametricRef,
+    center: DVec3,
+    radius: f64,
+}
+
 /// The reference's Linear/Horizontal/Vertical/Aligned dimensional constraint:
 /// two constraint points (or one object's ends), a dimension line location,
 /// then the parameter name and expression the dynamic dimension carries.
@@ -167,15 +177,13 @@ impl DimConstraintCommand {
         "The object or point is already selected.  Select a different object or constraint point.";
     pub const INVALID_LINE: &'static str = "Invalid selection for Aligned. Select a line segment, polyline segment, text, MText, major or minor axis of ellipse or elliptical arc.";
     pub const PARALLEL_LINES: &'static str = "Lines are parallel.";
-    pub const INVALID_RADIAL: &'static str =
-        "Invalid selection for Radial. Select a circle or arc.";
 
     pub fn new(axis: DimConstraintAxis, default_name: String) -> Self {
         Self {
             axis,
             step: match axis {
                 DimConstraintAxis::Angular => Step::AngularFirst,
-                DimConstraintAxis::Radius => Step::RadialSelect,
+                DimConstraintAxis::Radius | DimConstraintAxis::Diameter => Step::RadialObject,
                 _ => Step::First,
             },
             picked_entity: None,
@@ -318,25 +326,6 @@ impl DimConstraintCommand {
         })
     }
 
-    fn build_radial(&self, name: String, expression: String) -> Option<CmdResult> {
-        let Step::RadialValue {
-            circle, location, ..
-        } = self.step
-        else {
-            return None;
-        };
-        if expression.trim().is_empty() {
-            return None;
-        }
-        Some(CmdResult::AddRadialConstraint {
-            circle,
-            location,
-            renamed: name != self.default_name,
-            name,
-            expression,
-        })
-    }
-
     fn command_name(&self) -> &'static str {
         match self.axis {
             DimConstraintAxis::Linear => "DCLINEAR",
@@ -345,6 +334,7 @@ impl DimConstraintCommand {
             DimConstraintAxis::Aligned => "DCALIGNED",
             DimConstraintAxis::Angular => "DCANGULAR",
             DimConstraintAxis::Radius => "DCRADIUS",
+            DimConstraintAxis::Diameter => "DCDIAMETER",
         }
     }
 
@@ -355,10 +345,47 @@ impl DimConstraintCommand {
             DimConstraintAxis::Vertical => "Vertical",
             DimConstraintAxis::Aligned => "Aligned",
             DimConstraintAxis::Angular => "Angular",
-            DimConstraintAxis::Radius => "Radial",
+            DimConstraintAxis::Radius => "Radius",
+            DimConstraintAxis::Diameter => "Diameter",
         }
     }
 
+    /// The circle or arc a radial pick landed on, with its centre and radius.
+    fn radial_target(entity: &EntityType, handle: Handle) -> Option<RadialTarget> {
+        let (center, radius) = match entity {
+            EntityType::Circle(circle) => (circle.center, circle.radius),
+            EntityType::Arc(arc) => (arc.center, arc.radius),
+            _ => return None,
+        };
+        (radius > 1.0e-12).then_some(RadialTarget {
+            circle: ParametricRef::whole(handle),
+            center: DVec3::new(center.x, center.y, center.z),
+            radius,
+        })
+    }
+
+    fn build_radial(&self, name: String, expression: String) -> Option<CmdResult> {
+        let Step::RadialValue {
+            target, location, ..
+        } = self.step
+        else {
+            return None;
+        };
+        if expression.trim().is_empty() {
+            return None;
+        }
+        Some(CmdResult::AddRadialConstraint {
+            circle: target.circle,
+            center: target.center,
+            radius: target.radius,
+            location,
+            diameter: self.axis == DimConstraintAxis::Diameter,
+            renamed: name != self.default_name,
+            name,
+            expression,
+        })
+    }
+
     fn report(message: &str) -> CmdResult {
         CmdResult::ReportError(message.to_string())
     }
@@ -509,8 +536,11 @@ impl DimConstraintCommand {
             }
             DimConstraintAxis::Horizontal => (ConstraintKind::DistanceX, DVec3::X),
             DimConstraintAxis::Vertical => (ConstraintKind::DistanceY, DVec3::Y),
-            // Angular and Radius never measure here; their own steps decide.
-            DimConstraintAxis::Aligned | DimConstraintAxis::Angular | DimConstraintAxis::Radius => (
+            // Angular never measures here; its own steps decide the sector.
+            DimConstraintAxis::Aligned
+            | DimConstraintAxis::Angular
+            | DimConstraintAxis::Radius
+            | DimConstraintAxis::Diameter => (
                 ConstraintKind::Distance,
                 (second - first).normalize_or(DVec3::X),
             ),
@@ -560,9 +590,10 @@ impl DimConstraintCommand {
                 DimConstraintAxis::Linear => "Linear constraint",
                 DimConstraintAxis::Horizontal => "Horizontal distance constraint",
                 DimConstraintAxis::Vertical => "Vertical distance constraint",
-                DimConstraintAxis::Aligned | DimConstraintAxis::Angular | DimConstraintAxis::Radius => {
-                    "Aligned constraint"
-                }
+                DimConstraintAxis::Aligned
+                | DimConstraintAxis::Angular
+                | DimConstraintAxis::Radius
+                | DimConstraintAxis::Diameter => "Aligned constraint",
             },
         })
     }
@@ -604,17 +635,22 @@ impl CadCommand for DimConstraintCommand {
             Step::AngularPoint2 { .. } => {
                 format!("{name}  Specify second angle constraint point:")
             }
-            Step::RadialSelect => format!("{name}  Select arc or circle:"),
-            Step::AngularLocation { .. } | Step::Location { .. } | Step::RadialLocation { .. } => {
+            Step::RadialObject => format!("{name}  Select arc or circle:"),
+            Step::AngularLocation { .. }
+            | Step::Location { .. }
+            | Step::RadialLocation { .. } => {
                 format!("{name}  Specify dimension line location:")
             }
-            Step::AngularValue { measured, .. } | Step::RadialValue { radius: measured, .. } => {
-                format!(
-                    "{name}  Enter value or name and value <{}={}>:",
-                    self.default_name,
-                    measured_expression(measured)
-                )
-            }
+            Step::RadialValue { measured, .. } => format!(
+                "{name}  Enter value or name and value <{}={}>:",
+                self.default_name,
+                measured_expression(measured)
+            ),
+            Step::AngularValue { measured, .. } => format!(
+                "{name}  Enter value or name and value <{}={}>:",
+                self.default_name,
+                measured_expression(measured)
+            ),
             Step::Value { measured, .. } => format!(
                 "{name}  Enter value or name and value <{}={}>:",
                 self.default_name,
@@ -717,7 +753,7 @@ impl CadCommand for DimConstraintCommand {
                 | Step::AngularVertex
                 | Step::AngularPoint1 { .. }
                 | Step::AngularPoint2 { .. }
-                | Step::RadialSelect
+                | Step::RadialObject
         )
     }
 
@@ -909,27 +945,30 @@ impl CadCommand for DimConstraintCommand {
                     whole_curve: false,
                 })
             }
-            Step::RadialSelect => {
+            Step::RadialObject => {
                 if handle.is_null() {
                     return Self::report(Self::NO_OBJECT);
                 }
                 let Some(entity) = self.picked_entity.take() else {
                     return CmdResult::NeedPoint;
                 };
-                let radius = match &entity {
-                    EntityType::Circle(circle) => circle.radius,
-                    EntityType::Arc(arc) => arc.radius,
-                    _ => return Self::report(Self::INVALID_RADIAL),
+                let Some(target) = Self::radial_target(&entity, handle) else {
+                    return Self::report(&format!(
+                        "Invalid selection for {}. Select a circle or arc.",
+                        self.noun()
+                    ));
                 };
-                self.step = Step::RadialLocation {
-                    circle: ParametricRef::whole(handle),
-                    radius,
+                let measured = if self.axis == DimConstraintAxis::Diameter {
+                    target.radius * 2.0
+                } else {
+                    target.radius
                 };
-                // The reference reports the radius before asking where the
-                // dimension goes.
+                self.step = Step::RadialLocation { target };
+                // The measured size is reported before the location, as the
+                // reference prints it, with trailing zeros suppressed.
                 CmdResult::ReportMeasurement(format!(
                     "Dimension text = {}",
-                    measured_expression(radius)
+                    measured_expression(measured)
                 ))
             }
             Step::Location { .. }
@@ -1065,16 +1104,7 @@ impl CadCommand for DimConstraintCommand {
             | Step::TwoLinesFirst
             | Step::TwoLinesSecond { .. }
             | Step::AngularFirst
-            | Step::AngularSecond { .. }
-            | Step::RadialSelect => Self::report(Self::NO_OBJECT),
-            Step::RadialLocation { circle, radius } => {
-                self.step = Step::RadialValue {
-                    circle,
-                    radius,
-                    location: point,
-                };
-                CmdResult::NeedPoint
-            }
+            | Step::AngularSecond { .. } => Self::report(Self::NO_OBJECT),
             Step::AngularLocation { data } => {
                 let frame = match data {
                     AngularData::Lines { first, second } => Self::angle_frame(
@@ -1126,6 +1156,20 @@ impl CadCommand for DimConstraintCommand {
                 };
                 CmdResult::ReportMeasurement(format!("Dimension text = {measured:.4}"))
             }
+            Step::RadialObject => Self::report(Self::NO_OBJECT),
+            Step::RadialLocation { target } => {
+                let measured = if self.axis == DimConstraintAxis::Diameter {
+                    target.radius * 2.0
+                } else {
+                    target.radius
+                };
+                self.step = Step::RadialValue {
+                    target,
+                    location: point,
+                    measured,
+                };
+                CmdResult::NeedPoint
+            }
             Step::TwoLinesParallel { .. }
             | Step::Value { .. }
             | Step::AngularValue { .. }
@@ -1147,9 +1191,6 @@ impl CadCommand for DimConstraintCommand {
             Step::AngularValue { measured, .. } => self
                 .build_angular(self.default_name.clone(), measured_expression(measured))
                 .unwrap_or(CmdResult::Cancel),
-            Step::RadialValue { radius, .. } => self
-                .build_radial(self.default_name.clone(), measured_expression(radius))
-                .unwrap_or(CmdResult::Cancel),
             Step::PointLinePoint => {
                 self.step = Step::LineFirst;
                 CmdResult::NeedPoint
@@ -1157,6 +1198,9 @@ impl CadCommand for DimConstraintCommand {
             Step::Value { measured, .. } => self
                 .build(self.default_name.clone(), measured_expression(measured))
                 .unwrap_or(CmdResult::Cancel),
+            Step::RadialValue { measured, .. } => self
+                .build_radial(self.default_name.clone(), measured_expression(measured))
+                .unwrap_or(CmdResult::Cancel),
             _ => CmdResult::Cancel,
         }
     }