Ruled Surface: strips off an edge chain, exact where possible (#762) (#1151)

Ruled Surface: strips off an edge chain in normal, tangent, angle or direction mode, exact planes/cylinders/cones where possible, mitred or round corners, stitched into one surface body. SurfaceRuled is noted under format 21. Closes #762.

crates/doc/src/document.rs

@@ -138,6 +138,44 @@ pub enum Direction {
     Symmetric,
 }
 
+/// The direction a ruled surface leaves its edges (`surface.ruled`).
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Default, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum RuledMode {
+    /// Along the normal of the face beside each edge.
+    #[default]
+    Normal,
+    /// Continuing the face beside each edge.
+    Tangent,
+    /// At an angle from a reference direction (the face's normal unless one is given).
+    Angle,
+    /// Along a fixed direction.
+    Direction,
+}
+
+impl RuledMode {
+    fn is_normal(&self) -> bool {
+        *self == RuledMode::Normal
+    }
+}
+
+/// How a ruled surface's strips meet at sharp corners of its edge chain.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Default, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum RuledCorners {
+    /// Extended or cut back until they meet.
+    #[default]
+    Mitre,
+    /// Joined by a sector (inside corners are cut back).
+    Round,
+}
+
+impl RuledCorners {
+    fn is_mitre(&self) -> bool {
+        *self == RuledCorners::Mitre
+    }
+}
+
 /// Angular starts in older designs used the raw axis sign. New revolves measure starts
 /// along the same sketch-normal sweep direction as the kernel.
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Default, Serialize, Deserialize)]
@@ -1078,6 +1116,27 @@ pub enum FeatureKind {
         #[serde(default, skip_serializing_if = "Option::is_none")]
         tolerance: Option<String>,
     },
+    /// A strip of ruled surface `distance` wide hanging off the chain of `body`'s edges through
+    /// `edges`, as a new surface body: along `mode` (`angle` from `direction`, or from the
+    /// face's normal; along `direction`), from the face at `face` where it borders the chain;
+    /// `flip` puts it on the other side; sharp corners as `corners` says.
+    SurfaceRuled {
+        body: String,
+        edges: Vec<Vec3>,
+        distance: String,
+        #[serde(default, skip_serializing_if = "RuledMode::is_normal")]
+        mode: RuledMode,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        angle: Option<String>,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        direction: Option<Vec3>,
+        #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+        flip: bool,
+        #[serde(default, skip_serializing_if = "RuledCorners::is_mitre")]
+        corners: RuledCorners,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        face: Option<Vec3>,
+    },
     /// A planar surface body extended outward by `distance` past the edges through `edges`.
     SurfaceExtend {
         body: String,
@@ -1455,6 +1514,7 @@ impl FeatureKind {
             FeatureKind::Thicken { .. } => "ThickenFeature",
             FeatureKind::SurfaceTrim { .. } => "TrimFeature",
             FeatureKind::SurfaceExtend { .. } => "ExtendFeature",
+            FeatureKind::SurfaceRuled { .. } => "RuledSurfaceFeature",
             FeatureKind::Unstitch { .. } => "UnstitchFeature",
             FeatureKind::ReverseNormal { .. } => "ReverseNormalFeature",
             FeatureKind::SurfaceUntrim { .. } => "UntrimFeature",
@@ -1530,6 +1590,7 @@ impl FeatureKind {
             FeatureKind::Thicken { .. } => "Thicken",
             FeatureKind::SurfaceTrim { .. } => "Trim",
             FeatureKind::SurfaceExtend { .. } => "Extend",
+            FeatureKind::SurfaceRuled { .. } => "RuledSurface",
             FeatureKind::Unstitch { .. } => "Unstitch",
             FeatureKind::ReverseNormal { .. } => "ReverseNormal",
             FeatureKind::SurfaceUntrim { .. } => "Untrim",