From 4f57053c4595d8f20aa4aaae67b83aa114eb35a5 Mon Sep 17 00:00:00 2001
From: Korijn van Golen <k.vangolen@mapiq.com>
Date: Fri, 10 Jan 2025 11:10:58 +0100
Subject: [PATCH] add test

---
 pylinalg/vector.py     |  4 +++-
 tests/test_pylinalg.py | 12 ++++++------
 tests/test_vectors.py  | 10 ++++++++++
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/pylinalg/vector.py b/pylinalg/vector.py
index b03e031..a024b0a 100644
--- a/pylinalg/vector.py
+++ b/pylinalg/vector.py
@@ -167,7 +167,9 @@ def vec_unproject(
     if out is None:
         out = np.empty((*result_shape, 3), dtype=dtype)
 
-    if not matrix_is_inv:
+    if matrix_is_inv:
+        inverse_projection = matrix
+    else:
         from .matrix import mat_inverse
 
         inverse_projection = mat_inverse(matrix, raise_err=True)
diff --git a/tests/test_pylinalg.py b/tests/test_pylinalg.py
index d67e854..1afa66c 100644
--- a/tests/test_pylinalg.py
+++ b/tests/test_pylinalg.py
@@ -58,9 +58,9 @@ def popattr(key):
         # confirm the signature of each callable
         sig = inspect.signature(getattr(la, key))
 
-        assert (
-            sig.return_annotation is not inspect.Signature.empty
-        ), f"Missing return annotation on {key}"
+        assert sig.return_annotation is not inspect.Signature.empty, (
+            f"Missing return annotation on {key}"
+        )
         if sig.return_annotation is bool:
             key_parts = key.split("_")
             assert key_parts[1] in ("is", "has")
@@ -77,9 +77,9 @@ def popattr(key):
                     assert param.KEYWORD_ONLY
                     has_out = True
             assert has_out, f"Function {key} does not have 'out' keyword-only argument"
-            assert (
-                has_dtype
-            ), f"Function {key} does not have 'dtype' keyword-only argument"
+            assert has_dtype, (
+                f"Function {key} does not have 'dtype' keyword-only argument"
+            )
 
     # assert that all callables are available in __all__
     assert set(__all__) == set(callables)
diff --git a/tests/test_vectors.py b/tests/test_vectors.py
index e69dd68..b5e923b 100644
--- a/tests/test_vectors.py
+++ b/tests/test_vectors.py
@@ -303,6 +303,16 @@ def test_vec_unproject_exceptions():
         la.vec_unproject(vector, matrix)
 
 
+def test_vec_unproject_is_inverse():
+    a = la.mat_perspective(-1, 1, -1, 1, 1, 100)
+    a_inv = la.mat_inverse(a)
+    vecs = np.array([[1, 2], [4, 5], [7, 8]])
+
+    expected = la.vec_unproject(vecs, a)
+    actual = la.vec_unproject(vecs, a_inv, matrix_is_inv=True)
+    npt.assert_array_equal(expected, actual)
+
+
 def test_vector_apply_rotation_ordered():
     """Test that a positive pi/2 rotation about the z-axis and then the y-axis
     results in a different output then in standard rotation ordering."""