Use circle planes in offset and break

src/modules/draw/modify/break_cmd.rs

@@ -126,8 +126,15 @@ fn break_circle(circle: &acadrust::entities::Circle, p1: DVec3, p2: DVec3) -> Ve
     let cx = circle.center.x;
     let cy = circle.center.y;
 
-    let a1 = angle_on_arc(cx, cy, p1);
-    let a2 = angle_on_arc(cx, cy, p2);
+    let plane = crate::entities::curve::circle_curve(circle).plane;
+    let Some(q1) = plane.project(p1.to_array()) else {
+        return vec![EntityType::Circle(circle.clone())];
+    };
+    let Some(q2) = plane.project(p2.to_array()) else {
+        return vec![EntityType::Circle(circle.clone())];
+    };
+    let a1 = angle_on_arc(cx, cy, DVec3::new(q1[0], q1[1], 0.0));
+    let a2 = angle_on_arc(cx, cy, DVec3::new(q2[0], q2[1], 0.0));
 
     if (a1 - a2).abs() < 0.01 {
         return vec![EntityType::Circle(circle.clone())];
@@ -139,6 +146,7 @@ fn break_circle(circle: &acadrust::entities::Circle, p1: DVec3, p2: DVec3) -> Ve
     arc.common.handle = Handle::NULL;
     arc.center = circle.center.clone();
     arc.radius = circle.radius;
+    arc.thickness = circle.thickness;
     arc.normal = circle.normal.clone();
     arc.start_angle = a2;
     arc.end_angle = a1;

src/modules/draw/modify/offset.rs

@@ -105,8 +105,8 @@ fn offset_xline(x: &XLineEnt, dist: f64, side_pt: Vec3) -> Option<EntityType> {
 // ── Circle offset ──────────────────────────────────────────────────────────
 
 fn offset_circle(c: &CircleEnt, dist: f64, side_pt: Vec3) -> Option<EntityType> {
-    let px = side_pt.x as f64;
-    let py = side_pt.y as f64;
+    let plane = crate::entities::curve::circle_curve(c).plane;
+    let [px, py] = plane.project(side_pt.as_dvec3().to_array())?;
     let dc = ((px - c.center.x).powi(2) + (py - c.center.y).powi(2)).sqrt();
 
     let new_r = if dc < c.radius {