feat: plinegen + SAB parsing for Solid3D/Region/Body

LwPolyline PLINEGEN=0 (DXF default): emit SegmentedLines with NaN
separators between vertex-to-vertex segments; wire_gpu resets
arc-length to 0 after each NaN so linetype pattern restarts per vertex.
PLINEGEN=1: existing Contour path unchanged (continuous pattern).
WireModel gains plinegen field propagated through tessellate pipeline.

Solid3D/Region/Body: call SabReader::read() when parse_sat() returns
None due to binary SAB format (DWG files / newer AutoCAD exports).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/scene/acad_to_truck.rs

@@ -23,6 +23,8 @@ pub enum TruckObject {
     Text(Vec<TextStroke>),
     /// Pre-computed NaN-separated 3-D point list (leader lines, arrowheads, etc.).
     Lines(Vec<[f32; 3]>),
+    /// Like Lines but linetype pattern restarts at each NaN-separated segment (plinegen=false).
+    SegmentedLines(Vec<[f32; 3]>),
     Volume(Solid),
 }
 

src/scene/complex_lt.rs

@@ -202,6 +202,7 @@ pub fn apply_along(
             aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
         })
         .collect()
 }

src/scene/mod.rs

@@ -3211,6 +3211,7 @@ fn tessellate_entity(
             tangent_geoms: vec![],
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
         });
         return wires;
     }

src/scene/pipeline/wire_gpu.rs

@@ -148,7 +148,12 @@ impl WireGpu {
                 let p = wire.points[i - 1];
                 let q = wire.points[i];
                 if !p[0].is_finite() || !q[0].is_finite() {
-                    dists[i] = dists[i - 1];
+                    // plinegen=false: reset to 0 at the first real point after a NaN separator.
+                    dists[i] = if !wire.plinegen && !p[0].is_finite() && q[0].is_finite() {
+                        0.0
+                    } else {
+                        dists[i - 1]
+                    };
                 } else {
                     let dx = q[0] - p[0];
                     let dy = q[1] - p[1];
@@ -234,10 +239,13 @@ impl WireGpu {
         for i in 1..n {
             let p = wire.points[i - 1];
             let q = wire.points[i];
-            // If either point is non-finite (NaN sentinel or ±inf from overflow),
-            // keep the same distance — the segment will be skipped anyway.
             if !p[0].is_finite() || !q[0].is_finite() {
-                dists[i] = dists[i - 1];
+                // plinegen=false: reset to 0 at the first real point after a NaN separator.
+                dists[i] = if !wire.plinegen && !p[0].is_finite() && q[0].is_finite() {
+                    0.0
+                } else {
+                    dists[i - 1]
+                };
             } else {
                 let dx = q[0] - p[0];
                 let dy = q[1] - p[1];

src/scene/solid3d_tess.rs

@@ -14,8 +14,8 @@ use std::collections::HashSet;
 use std::f64::consts::TAU;
 
 use acadrust::entities::acis::{
-    SatCoedge, SatConeSurface, SatDocument, SatEdge, SatFace, SatLoop, SatPlaneSurface, SatPoint,
-    SatPointer, SatSphereSurface, SatTorusSurface, SatVertex,
+    SabReader, SatCoedge, SatConeSurface, SatDocument, SatEdge, SatFace, SatLoop,
+    SatPlaneSurface, SatPoint, SatPointer, SatSphereSurface, SatTorusSurface, SatVertex,
 };
 use acadrust::entities::acis::types::Sense;
 use acadrust::entities::{Body, Region, Solid3D};
@@ -67,16 +67,26 @@ fn tessellate_sat(sat: &SatDocument, name: String, color: [f32; 4]) -> Option<Me
     Some(MeshModel { name, verts, normals, indices, color, selected: false })
 }
 
+fn parse_acis(sat_fn: impl FnOnce() -> Option<SatDocument>, is_binary: bool, sab_data: &[u8]) -> Option<SatDocument> {
+    if let Some(doc) = sat_fn() {
+        return Some(doc);
+    }
+    if is_binary && !sab_data.is_empty() {
+        return SabReader::read(sab_data).ok();
+    }
+    None
+}
+
 /// Tessellate a `Region` entity (2D planar ACIS body) into a `MeshModel`.
 pub fn tessellate_region(region: &Region, color: [f32; 4]) -> Option<MeshModel> {
-    let sat = region.parse_sat()?;
+    let sat = parse_acis(|| region.parse_sat(), region.acis_data.is_binary, &region.acis_data.sab_data)?;
     let name = region.common.handle.value().to_string();
     tessellate_sat(&sat, name, color)
 }
 
 /// Tessellate a `Body` entity (3D ACIS body) into a `MeshModel`.
 pub fn tessellate_body(body: &Body, color: [f32; 4]) -> Option<MeshModel> {
-    let sat = body.parse_sat()?;
+    let sat = parse_acis(|| body.parse_sat(), body.acis_data.is_binary, &body.acis_data.sab_data)?;
     let name = body.common.handle.value().to_string();
     tessellate_sat(&sat, name, color)
 }
@@ -86,7 +96,7 @@ pub fn tessellate_body(body: &Body, color: [f32; 4]) -> Option<MeshModel> {
 /// Returns `None` when the entity has no parseable SAT data or produces no
 /// triangles (e.g. the solid uses only unsupported surface types).
 pub fn tessellate_solid3d(solid: &Solid3D, color: [f32; 4]) -> Option<MeshModel> {
-    let sat = solid.parse_sat()?;
+    let sat = parse_acis(|| solid.parse_sat(), solid.acis_data.is_binary, &solid.acis_data.sab_data)?;
     let name = solid.common.handle.value().to_string();
     tessellate_sat(&sat, name, color)
 }

src/scene/tessellate.rs

@@ -104,6 +104,7 @@ pub fn tessellate(
                     aci: 0,
             key_vertices: te.key_vertices,
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
                 };
             }
 
@@ -132,6 +133,7 @@ pub fn tessellate(
                             aci: 0,
                             key_vertices: te.key_vertices,
                             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
                         };
                     }
                     _ => {}
@@ -158,6 +160,7 @@ pub fn tessellate(
                         aci: 0,
                         key_vertices,
                         aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
                     };
                 }
             }
@@ -182,6 +185,7 @@ pub fn tessellate(
                         aci: 0,
                         key_vertices,
                         aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
                     };
                 }
             }
@@ -212,6 +216,34 @@ pub fn tessellate(
                     aci: 0,
                     key_vertices,
                     aabb: WireModel::UNBOUNDED_AABB,
+                    plinegen: true,
+                };
+            }
+
+            TruckObject::SegmentedLines(points) => {
+                let [ox, oy, oz] = world_offset;
+                let local_pts: Vec<[f32; 3]> = points.into_iter().map(|[x, y, z]| {
+                    if x.is_nan() { [x, y, z] }
+                    else { [x - ox as f32, y - oy as f32, z - oz as f32] }
+                }).collect();
+                let snap_pts = offset_snap_pts(te.snap_pts, world_offset);
+                let key_vertices: Vec<[f32; 3]> = te.key_vertices.into_iter()
+                    .map(|[x, y, z]| [x - ox as f32, y - oy as f32, z - oz as f32])
+                    .collect();
+                return WireModel {
+                    name,
+                    points: local_pts,
+                    color,
+                    selected,
+                    pattern_length,
+                    pattern,
+                    line_weight_px,
+                    snap_pts,
+                    tangent_geoms: te.tangent_geoms,
+                    aci: 0,
+                    key_vertices,
+                    plinegen: false,
+                    aabb: WireModel::UNBOUNDED_AABB,
                 };
             }
 
@@ -241,6 +273,7 @@ pub fn tessellate(
         tangent_geoms,
         key_vertices,
         aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
     }
 }
 
@@ -296,6 +329,7 @@ pub fn tessellate_dimension(
         tangent_geoms: vec![],
         key_vertices,
         aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
     }];
 
     if let Some(text) = dimension_text_entity(dim) {
@@ -344,6 +378,7 @@ fn tessellate_leader(
             aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
         }];
     }
 
@@ -412,6 +447,7 @@ fn tessellate_leader(
         tangent_geoms: vec![],
         key_vertices,
         aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
     }]
 }
 
@@ -521,6 +557,7 @@ fn tessellate_multileader(
         aci: 0,
             key_vertices: key_verts,
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
     }];
 
     // Render text content as MText wire

src/scene/wire_model.rs

@@ -60,6 +60,9 @@ pub struct WireModel {
     /// Preview / interim wires use `UNBOUNDED_AABB` so they are never pre-rejected
     /// by the snap world-space filter.
     pub aabb: [f32; 4],
+    /// When false the linetype pattern restarts at each NaN-separated segment
+    /// (DXF PLINEGEN=0).  When true the pattern runs continuously (PLINEGEN=1).
+    pub plinegen: bool,
 }
 
 impl WireModel {
@@ -85,6 +88,7 @@ impl WireModel {
             tangent_geoms: vec![],
             key_vertices: vec![],
             aabb: Self::UNBOUNDED_AABB,
+            plinegen: true,
         }
     }
 
@@ -184,6 +188,7 @@ impl Default for WireModel {
             tangent_geoms: Vec::new(),
             key_vertices: Vec::new(),
             aabb: Self::UNBOUNDED_AABB,
+            plinegen: true,
         }
     }
 }