Get nearest patch

fdsreader/bndf/obstruction.py

@@ -574,24 +574,31 @@ def get_nearest_patch(self, x: float = None, y: float = None, z: float = None):
         """
         if self.has_boundary_data:
             d_min = np.finfo(float).max
-            patches_min = list()
+            patches_with_dist = list()
 
             for subobst in self._subobstructions.values():
                 for patch in subobst.get_data(self.quantities[0])._patches:
                     dx = max(patch.extent.x_start - x, 0, x - patch.extent.x_end) if x is not None else 0
                     dy = max(patch.extent.y_start - y, 0, y - patch.extent.y_end) if y is not None else 0
                     dz = max(patch.extent.z_start - z, 0, z - patch.extent.z_end) if z is not None else 0
                     d = np.sqrt(dx * dx + dy * dy + dz * dz)
-                    if d <= d_min:
+                    if d < d_min:
                         d_min = d
-                        patches_min.append(patch)
-
-            if x is not None:
-                patches_min.sort(key=lambda patch: (patch.extent.x_end - patch.extent.x_start))
-            if y is not None:
-                patches_min.sort(key=lambda patch: (patch.extent.y_end - patch.extent.y_start))
-            if z is not None:
-                patches_min.sort(key=lambda patch: (patch.extent.z_end - patch.extent.z_start))
+                        patches_with_dist = [(patch, dx, dy, dz)]
+                    elif math.isclose(d, d_min, rel_tol=1e-9, abs_tol=0.0):
+                        patches_with_dist.append((patch, dx, dy, dz))
+
+            patches_min = [p[0] for p in patches_with_dist]
+
+            if x is not None and len(patches_with_dist) > 1:
+                patches_with_dist.sort(key=lambda p: p[1])
+                patches_min = [p[0] for p in patches_with_dist]
+            elif y is not None and len(patches_with_dist) > 1:
+                patches_with_dist.sort(key=lambda p: p[2])
+                patches_min = [p[0] for p in patches_with_dist]
+            elif z is not None and len(patches_with_dist) > 1:
+                patches_with_dist.sort(key=lambda p: p[3])
+                patches_min = [p[0] for p in patches_with_dist]
 
             if len(patches_min) > 0:
                 return patches_min[0]

tests/acceptance_tests/test_bndf.py

@@ -1,9 +1,36 @@
+import os
 from fdsreader import Simulation
 
+TEST_DIR = os.path.dirname(os.path.abspath(__file__))
+
 
 def test_bndf():
-    sim = Simulation("./bndf_data")
+    sim = Simulation(os.path.join(TEST_DIR, "../cases/bndf_data"))
     obst = sim.obstructions.get_nearest(-0.8, 1, 1)
     face = obst.get_global_boundary_data_arrays("Wall Temperature")[1]
 
     assert len(face[-1]) == 68
+
+
+def test_get_nearest_patch():
+    """Test that get_nearest_patch returns correct face based on distance."""
+    sim = Simulation(os.path.join(TEST_DIR, "../cases/bndf_data"))
+    obst = sim.obstructions[0]
+
+    # Get patches for different points around the obstruction
+    # Bounding box: x=[-1, 2], y=[-1.2, 2.4], z=[-0.1, 0]
+    # Use z slightly inside the obstruction for side faces to avoid edge/face ties.
+    patch_x_plus = obst.get_nearest_patch(3, 0.5, -0.05)
+    patch_x_minus = obst.get_nearest_patch(-2, 0.5, -0.05)
+    patch_y_plus = obst.get_nearest_patch(0.5, 3, -0.05)
+    patch_y_minus = obst.get_nearest_patch(0.5, -2, -0.05)
+    patch_z_plus = obst.get_nearest_patch(0.5, 0.5, 1)
+
+    # Orientations: 1=X+, 2=Y+, 3=Z+, -1=X-, -2=Y-, -3=Z-
+    assert patch_x_plus.orientation == 1
+    assert patch_x_minus.orientation == -1
+    assert patch_y_plus.orientation == 2
+    assert patch_y_minus.orientation == -2
+    assert patch_z_plus.orientation == 3
+
+    # Note: no -3 (z-minus) patch exists in this test data, so -z is not tested