- arc improvements, fillets, operations, bodys

src/fluency/sketch_solver.py

@@ -187,19 +187,29 @@ class SolverSketch(SolverSystem):
     def constrain_distance(
         self, entity_a, entity_b, distance: float
     ) -> bool:
-        """Constrain distance between point-point or point-line."""
+        """Constrain distance between point-point or point-line.
+
+        python-solvespace's ``distance`` accepts (point, line) ordering only,
+        so line-point pairs are normalised; line-line pairs and a point
+        constrained to itself are rejected (the solver cannot hold them).
+        """
         try:
-            handle_a = entity_a.handle if isinstance(entity_a, SolverPoint) else entity_a.handle
-            handle_b = entity_b.handle if isinstance(entity_b, SolverPoint) else entity_b.handle
+            if isinstance(entity_a, SolverLine) and isinstance(entity_b, SolverLine):
+                logger.warning("distance: line-to-line distance is not supported")
+                return False
+            if isinstance(entity_a, SolverLine) and isinstance(entity_b, SolverPoint):
+                # Normalise to (point, line) ordering.
+                entity_a, entity_b = entity_b, entity_a
+            if entity_a is entity_b and distance != 0.0:
+                logger.warning("distance: refusing point-to-itself constraint")
+                return False
+            handle_a = entity_a.handle
+            handle_b = entity_b.handle
 
             if isinstance(entity_a, SolverPoint) and isinstance(entity_b, SolverLine):
                 self.distance(handle_a, handle_b, distance, self.wp)
-            elif isinstance(entity_a, SolverLine) and isinstance(entity_b, SolverPoint):
-                self.distance(handle_b, handle_a, distance, self.wp)
             elif isinstance(entity_a, SolverPoint) and isinstance(entity_b, SolverPoint):
                 self.distance(handle_a, handle_b, distance, self.wp)
-            elif isinstance(entity_a, SolverLine) and isinstance(entity_b, SolverLine):
-                self.distance(handle_a, handle_b, distance, self.wp)
             else:
                 logger.warning(f"distance: unsupported types {type(entity_a)}, {type(entity_b)}")
                 return False