Extend GPU analytical circle and arc rendering to block inserts

- Emit transformed analytical curves (circles, arcs, ellipses) in block
  expansion as standalone wires rather than merging them into batched line
  strips.
- Keep render_instance unset on analytical curves in block prototypes so
  they route directly to CircleGpu / EllipseGpu instead of BlockWireGpu.
- Support TangentGeom::Circle in extract_circle_instance and wire partitioning.
- Drop analytical tangents on wires clipped by xclip so clipped geometry
  falls back correctly to line segments.
- Add unit test verifying block circles and arcs extract as analytical GPU
  instances.

src/scene/cache/block_cache.rs

@@ -1108,7 +1108,7 @@ pub fn expand_insert(
         );
         let mut first = first_batches.finalize(&name, selected, bg_color);
         for wire in &mut first {
-            if wire.render_instance.is_none() {
+            if !is_standalone_analytical_curve(wire) && wire.render_instance.is_none() {
                 wire.render_instance = Some(
                     crate::scene::model::instance_model::RenderInstance {
                         source_id: crate::scene::model::instance_model::next_source_id(),
@@ -1149,7 +1149,7 @@ pub fn expand_insert(
     if let Some(guard) = prototype_guard.as_mut() {
         let translation = transform_translation(&xform);
         for wire in &mut wires {
-            if wire.render_instance.is_none() {
+            if !is_standalone_analytical_curve(wire) && wire.render_instance.is_none() {
                 wire.render_instance = Some(crate::scene::model::instance_model::RenderInstance {
                     source_id: crate::scene::model::instance_model::next_source_id(),
                     translation,
@@ -1314,6 +1314,20 @@ fn aabb_pixel_size(local_aabb: [f32; 4], world_per_pixel: f32) -> f32 {
     w.max(h) / world_per_pixel
 }
 
+fn is_standalone_analytical_curve(wire: &WireModel) -> bool {
+    wire.tangent_geoms.len() == 1
+        && wire.fill_tris.is_empty()
+        && wire.pick_tris.is_empty()
+        && wire.text_verts.is_empty()
+        && matches!(
+            wire.tangent_geoms[0],
+            TangentGeom::Circle { .. }
+                | TangentGeom::PlanarCircle { .. }
+                | TangentGeom::Arc { .. }
+                | TangentGeom::PlanarEllipse { .. }
+        )
+}
+
 struct ExpandCtx<'a> {
     cache: &'a BlockCache,
     ins_color: [f32; 4],
@@ -1931,12 +1945,14 @@ fn expand_defn(
                             .collect();
                         crate::scene::pick::xclip::clip_wires(&mut wires, &world_poly);
                         for wire in &mut wires {
-                            wire.render_instance = Some(
-                                crate::scene::model::instance_model::RenderInstance {
-                                    source_id: crate::scene::model::instance_model::next_source_id(),
-                                    translation,
-                                },
-                            );
+                            if !is_standalone_analytical_curve(wire) {
+                                wire.render_instance = Some(
+                                    crate::scene::model::instance_model::RenderInstance {
+                                        source_id: crate::scene::model::instance_model::next_source_id(),
+                                        translation,
+                                    },
+                                );
+                            }
                         }
                         out.extra_wires.extend(wires.iter().cloned());
                         first = Some((wires, translation));
@@ -1984,7 +2000,7 @@ fn expand_defn(
                             );
                             let mut wires = sub.finalize("", ctx.selected, ctx.bg_color);
                             for wire in &mut wires {
-                                if wire.render_instance.is_none() {
+                                if !is_standalone_analytical_curve(wire) && wire.render_instance.is_none() {
                                     wire.render_instance = Some(
                                         crate::scene::model::instance_model::RenderInstance {
                                             source_id: crate::scene::model::instance_model::next_source_id(),
@@ -2297,6 +2313,127 @@ fn emit_wire(
         lw.line_weight_px
     };
 
+    // Analytical GPU circle / arc / ellipse fast path:
+    // If this LocalWire is a pure analytical curve (single tangent geometry, no fills/text/pick),
+    // and transforms cleanly with accum_xform into an analytical curve, emit it as a standalone
+    // wire in extra_wires. This lets partition_wires extract it into CircleGpu / EllipseGpu for
+    // pixel-perfect analytical rendering on the GPU instead of segmented lines.
+    if lw.tangent_geoms.len() == 1
+        && lw.fill_tris.is_empty()
+        && lw.pick_tris.is_empty()
+        && lw.text_verts.is_empty()
+    {
+        if let Some(tangent) = transform_tangent(&lw.tangent_geoms[0], accum_xform) {
+            if matches!(
+                tangent,
+                TangentGeom::Circle { .. }
+                    | TangentGeom::PlanarCircle { .. }
+                    | TangentGeom::Arc { .. }
+                    | TangentGeom::PlanarEllipse { .. }
+            ) {
+                let contrast_bg = lw.contrast_bg.unwrap_or(ctx.bg_color);
+                let color = if lw.canvas_color {
+                    ctx.bg_color
+                } else if lw.preserve_color {
+                    final_color
+                } else {
+                    crate::scene::view::render::adapt_to_bg(final_color, contrast_bg)
+                };
+                let bg_adapt: crate::scene::model::wire_model::BgAdapt =
+                    (lw.canvas_color || !lw.preserve_color).then(|| {
+                        Box::new(crate::scene::model::wire_model::BgAdaptInputs {
+                            raw_color: final_color,
+                            text_raw_colors: Vec::new(),
+                            contrast_bg: lw.contrast_bg,
+                            canvas_color: lw.canvas_color,
+                            preserve_color: lw.preserve_color,
+                        })
+                    });
+
+                let mut points = Vec::with_capacity(lw.points.len());
+                let mut points_low = Vec::with_capacity(lw.points.len());
+                let mut min_x = f32::INFINITY;
+                let mut min_y = f32::INFINITY;
+                let mut max_x = f32::NEG_INFINITY;
+                let mut max_y = f32::NEG_INFINITY;
+                for (idx, p) in lw.points.iter().enumerate() {
+                    let pl = lw.points_low.get(idx).copied().unwrap_or([0.0; 3]);
+                    let point = accum_xform.apply(Vector3::new(
+                        p[0] as f64 + pl[0] as f64,
+                        p[1] as f64 + pl[1] as f64,
+                        p[2] as f64 + pl[2] as f64,
+                    ));
+                    let (hx, lx) = WireModel::split_ds(point.x);
+                    let (hy, ly) = WireModel::split_ds(point.y);
+                    let (hz, lz) = WireModel::split_ds(point.z);
+                    if hx < min_x { min_x = hx; }
+                    if hy < min_y { min_y = hy; }
+                    if hx > max_x { max_x = hx; }
+                    if hy > max_y { max_y = hy; }
+                    points.push([hx, hy, hz]);
+                    points_low.push([lx, ly, lz]);
+                }
+                let aabb = if min_x.is_infinite() {
+                    WireModel::UNBOUNDED_AABB
+                } else {
+                    [min_x, min_y, max_x, max_y]
+                };
+                let mut snap_pts = Vec::with_capacity(lw.snap_pts.len());
+                for (p, hint) in &lw.snap_pts {
+                    let v = accum_xform.apply(Vector3::new(p.x, p.y, p.z));
+                    snap_pts.push((glam::DVec3::new(v.x, v.y, v.z), *hint));
+                }
+                let mut key_vertices = Vec::with_capacity(lw.key_vertices.len());
+                for p in &lw.key_vertices {
+                    let v = accum_xform.apply(Vector3::new(p[0], p[1], p[2]));
+                    key_vertices.push([v.x, v.y, v.z]);
+                }
+                let local_depth = if d_range != (0.0, 1.0) {
+                    Some(d_range.0)
+                } else {
+                    None
+                };
+
+                let wire = WireModel {
+                    bg_adapt,
+                    point_marker: lw.point_marker,
+                    taper_widths: Vec::new(),
+                    pattern_stations: Vec::new(),
+                    world_width: 0.0,
+                    depth_override: local_depth,
+                    display_visible: !lw.hide_unselected || ctx.selected,
+                    plot_visible: lw.plot_visible,
+                    fill_is_3d: false,
+                    fill_is_2d_solid: false,
+                    render_instance: None,
+                    pick_tris: Vec::new(),
+                    pick_tris_low: Vec::new(),
+                    dash_from_start: false,
+                    dash_align_end: None,
+                    text_verts: Vec::new(),
+                    name: String::new(),
+                    points,
+                    points_low,
+                    color,
+                    selected: ctx.selected,
+                    pattern_length: final_pat_len,
+                    pattern: final_pat,
+                    line_weight_px: final_lw_px,
+                    aci: final_aci,
+                    snap_pts,
+                    tangent_geoms: vec![tangent],
+                    key_vertices,
+                    aabb,
+                    plinegen: lw.plinegen,
+                    fill_tris: Vec::new(),
+                    fill_tris_low: Vec::new(),
+                };
+                out.extra_wires.push(wire);
+                return;
+            }
+        }
+    }
+
     let station_values = pattern_station_values(&lw.pattern_stations, lw.points.len());
     let station_map = decode_pattern_station_map(&lw.pattern_stations, lw.points.len());
     let transformed_stations = station_values.and_then(|(values, _)| {

src/scene/mod.rs

@@ -11284,4 +11284,45 @@ mod layout_cache_tests {
                 | crate::scene::model::wire_model::TangentGeom::Circle { .. }
         ));
     }
+
+    #[test]
+    fn block_circles_and_arcs_extract_as_analytical_gpu_instances() {
+        let mut s = Scene::new();
+        // Create initial entities
+        let mut circle = acadrust::entities::Circle::default();
+        circle.radius = 50.0;
+        let c_h = s.add_entity(EntityType::Circle(circle));
+
+        let mut arc = acadrust::entities::Arc::default();
+        arc.radius = 25.0;
+        arc.start_angle = 0.0;
+        arc.end_angle = 3.14159;
+        let a_h = s.add_entity(EntityType::Arc(arc));
+
+        let line = acadrust::entities::Line::from_points(
+            acadrust::types::Vector3::new(0.0, 0.0, 0.0),
+            acadrust::types::Vector3::new(100.0, 100.0, 0.0),
+        );
+        let l_h = s.add_entity(EntityType::Line(line));
+
+        // Create block and place insert at (200, 300, 0)
+        let xform = acadrust::types::Transform::from_translation(acadrust::types::Vector3::new(200.0, 300.0, 0.0));
+        let _ = s.create_block_from_entities(
+            &[c_h, a_h, l_h],
+            "TEST_ANALYTICAL_BLOCK",
+            &acadrust::types::Transform::identity(),
+            &xform,
+        ).unwrap();
+
+        let wires = s.model_tile_wires_arc(0, &Camera::default(), 1.0, 1000.0);
+        let depths = rustc_hash::FxHashMap::default();
+        let partitioned = crate::scene::pipeline::wire_arena::partition_wires(&wires, &depths);
+
+        // Both the circle and the arc inside the block must be extracted as analytical GPU circle instances!
+        assert!(
+            partitioned.circle_instances.len() >= 2,
+            "Expected at least 2 analytical circle instances from block, got {}",
+            partitioned.circle_instances.len()
+        );
+    }
 }

src/scene/pick/xclip.rs

@@ -197,6 +197,9 @@ pub fn clip_wires(wires: &mut Vec<WireModel>, poly: &[[f64; 2]]) {
             } else {
                 w.pattern_stations.clear();
             }
+            if !w.tangent_geoms.is_empty() {
+                w.tangent_geoms.clear();
+            }
         }
         if !w.fill_tris.is_empty() {
             let local: Vec<[f32; 3]> = (0..w.fill_tris.len())

src/scene/pipeline/circle_gpu.rs

@@ -215,6 +215,14 @@ pub fn extract_circle_instance(
         return None;
     }
     let (center, axis_x, axis_y, radius, start_angle, end_angle) = match wire.tangent_geoms[0] {
+        crate::scene::model::wire_model::TangentGeom::Circle { center, radius } => (
+            [center[0] as f64, center[1] as f64, center[2] as f64],
+            [1.0, 0.0, 0.0],
+            [0.0, 1.0, 0.0],
+            radius as f64,
+            0.0f32,
+            std::f32::consts::TAU,
+        ),
         crate::scene::model::wire_model::TangentGeom::PlanarCircle {
             center,
             axis_x,

src/scene/pipeline/wire_arena.rs

@@ -150,7 +150,8 @@ pub fn classify_wire(wire: &WireModel) -> WireKind {
         && wire.text_verts.is_empty()
     {
         match &wire.tangent_geoms[0] {
-            crate::scene::model::wire_model::TangentGeom::PlanarCircle { .. }
+            crate::scene::model::wire_model::TangentGeom::Circle { .. }
+            | crate::scene::model::wire_model::TangentGeom::PlanarCircle { .. }
             | crate::scene::model::wire_model::TangentGeom::Arc { .. } => {
                 if super::circle_gpu::extract_circle_instance(wire, 0.0).is_some() {
                     return WireKind::Circle;
@@ -214,7 +215,8 @@ pub fn partition_wires<'a>(
             && wire.text_verts.is_empty()
         {
             match &wire.tangent_geoms[0] {
-                crate::scene::model::wire_model::TangentGeom::PlanarCircle { .. }
+                crate::scene::model::wire_model::TangentGeom::Circle { .. }
+                | crate::scene::model::wire_model::TangentGeom::PlanarCircle { .. }
                 | crate::scene::model::wire_model::TangentGeom::Arc { .. } => {
                     if let Some(inst) = super::circle_gpu::extract_circle_instance(wire, depth) {
                         circle_instances.push(inst);