29 lines
871 B
Python
29 lines
871 B
Python
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import numpy as np
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import pyqtgraph as pg
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def test_qimage_writethrough():
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w, h = 256, 256
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backstore = np.ones((h, w), dtype=np.uint8)
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ptr0 = backstore.ctypes.data
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fmt = pg.Qt.QtGui.QImage.Format.Format_Grayscale8
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qimg = pg.functions.ndarray_to_qimage(backstore, fmt)
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def get_pointer(obj):
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if hasattr(obj, 'setsize'):
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return int(obj)
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else:
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return np.frombuffer(obj, dtype=np.uint8).ctypes.data
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# test that QImage is using the provided buffer (i.e. zero-copy)
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ptr1 = get_pointer(qimg.constBits())
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assert ptr0 == ptr1
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# test that QImage is not const (i.e. no COW)
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# if QImage is const, then bits() returns a copy
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ptr2 = get_pointer(qimg.bits())
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assert ptr1 == ptr2
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# test that data gets written through to provided buffer
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qimg.fill(0)
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assert np.all(backstore == 0)
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