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diff --git a/subprojects/pixpat/pixpat-python/tests/test_numpy.py b/subprojects/pixpat/pixpat-python/tests/test_numpy.py
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+++ b/subprojects/pixpat/pixpat-python/tests/test_numpy.py
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+"""Empirical check that pixpat works correctly with numpy.
+
+pixpat does not depend on numpy. This file proves that ndarrays work
+as ``Buffer`` planes through the buffer protocol, in the shapes a
+caller would typically use. Skipped when numpy is missing.
+"""
+
+import pixpat
+import pytest
+
+np = pytest.importorskip('numpy')
+
+
+def test_xrgb8888_into_uint8_3d_ndarray():
+    w, h = 64, 32
+    arr = np.zeros((h, w, 4), dtype=np.uint8)
+    pixpat.draw_pattern(pixpat.Buffer([arr], 'XRGB8888', w, h, [arr.strides[0]]), 'smpte')
+    assert arr.any()
+
+
+def test_abgr16161616_into_uint16_3d_ndarray():
+    w, h = 64, 32
+    arr = np.zeros((h, w, 4), dtype=np.uint16)
+    pixpat.draw_pattern(pixpat.Buffer([arr], 'ABGR16161616', w, h, [arr.strides[0]]), 'smpte')
+    assert arr.any()
+    assert arr.dtype == np.uint16
+
+
+def test_nv12_into_two_ndarrays():
+    w, h = 64, 32
+    y = np.zeros((h, w), dtype=np.uint8)
+    uv = np.zeros((h // 2, w), dtype=np.uint8)  # interleaved U,V at half-height
+    pixpat.draw_pattern(
+        pixpat.Buffer(
+            planes=[y, uv],
+            fmt='NV12',
+            width=w,
+            height=h,
+            strides=[y.strides[0], uv.strides[0]],
+        ),
+        'smpte',
+    )
+    assert y.any()
+    assert uv.any()
+
+
+def test_convert_with_readonly_ndarray_src():
+    """A numpy view with writeable=False must work as the convert source."""
+    w, h = 64, 32
+    src = np.zeros((h, w, 4), dtype=np.uint8)
+    pixpat.draw_pattern(pixpat.Buffer([src], 'XRGB8888', w, h, [src.strides[0]]), 'smpte')
+    src.flags.writeable = False
+
+    dst = np.zeros((h, w, 4), dtype=np.uint16)
+    pixpat.convert(
+        pixpat.Buffer([dst], 'ABGR16161616', w, h, [dst.strides[0]]),
+        pixpat.Buffer([src], 'XRGB8888', w, h, [src.strides[0]]),
+    )
+    assert dst.any()
+
+
+def test_roundtrip_ndarrays_byte_for_byte():
+    """End-to-end XRGB8888 -> ABGR16161616 -> XRGB8888 with ndarrays only."""
+    w, h = 64, 32
+    src = np.zeros((h, w, 4), dtype=np.uint8)
+    mid = np.zeros((h, w, 4), dtype=np.uint16)
+    dst = np.zeros((h, w, 4), dtype=np.uint8)
+
+    pixpat.draw_pattern(pixpat.Buffer([src], 'XRGB8888', w, h, [src.strides[0]]), 'smpte')
+    pixpat.convert(
+        pixpat.Buffer([mid], 'ABGR16161616', w, h, [mid.strides[0]]),
+        pixpat.Buffer([src], 'XRGB8888', w, h, [src.strides[0]]),
+    )
+    pixpat.convert(
+        pixpat.Buffer([dst], 'XRGB8888', w, h, [dst.strides[0]]),
+        pixpat.Buffer([mid], 'ABGR16161616', w, h, [mid.strides[0]]),
+    )
+    assert np.array_equal(src, dst)
+
+
+def test_writable_view_via_view_method():
+    """`arr.view()` shares memory and is writable by default — drawing into
+    it must update the original."""
+    w, h = 64, 32
+    arr = np.zeros((h, w, 4), dtype=np.uint8)
+    view = arr.view()
+    pixpat.draw_pattern(pixpat.Buffer([view], 'XRGB8888', w, h, [view.strides[0]]), 'smpte')
+    assert arr.any()  # the original sees the writes
+
+
+def test_noncontiguous_source_smoke():
+    """Discovery test: what happens if the caller hands us a non-C-contiguous
+    array? pixpat reads ``stride`` bytes per row, so any row-contiguous
+    layout where ``arr.strides[0]`` is the row stride should work; a
+    transposed array (where rows aren't even contiguous) is misuse.
+
+    This test passes a *valid* row-contiguous slice — the top half of a
+    bigger image, taken via slicing — and expects success. It exists to
+    document the contract: 'rows must be contiguous in memory; pass
+    arr.strides[0] as the stride'.
+    """
+    big = np.zeros((64, 64, 4), dtype=np.uint8)
+    top_half = big[:32]  # shape (32, 64, 4); rows still C-contiguous
+    assert top_half.strides[0] == 64 * 4
+    pixpat.draw_pattern(
+        pixpat.Buffer([top_half], 'XRGB8888', 64, 32, [top_half.strides[0]]),
+        'smpte',
+    )
+    assert big[:32].any()
+    assert not big[32:].any()  # the other half stayed untouched