Add High DPI curve plot test for reproducing #10

plotpy/tests/items/test_curves_highdpi.py

@@ -0,0 +1,40 @@
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see plotpy/LICENSE for details)
+
+"""Curve plotting test with high DPI"""
+
+# guitest: show,skip
+
+import os
+
+import numpy as np
+import pytest
+from guidata.qthelpers import qt_app_context
+
+from plotpy.builder import make
+from plotpy.tests import vistools as ptv
+
+# Performance should be the same with "1" and "2" scale factors:
+# (as of today, this is not the case, but it has to be fixed in the future:
+#  https://github.com/PlotPyStack/PlotPy/issues/10)
+os.environ["QT_SCALE_FACTOR"] = "2"
+
+
+@pytest.mark.skip(reason="This test is not relevant for the automated test suite")
+def test_plot_highdpi():
+    """Curve plotting test with high DPI"""
+    x = np.linspace(-10, 10, 5000000)  # 5M points are needed to see the difference
+    y = np.sin(np.sin(np.sin(x)))
+    with qt_app_context(exec_loop=True):
+        _win = ptv.show_items(
+            [make.curve(x, y, color="b"), make.legend("TR")],
+            wintitle=test_plot_highdpi.__doc__,
+            title="Curves with high DPI",
+            plot_type="curve",
+        )
+
+
+if __name__ == "__main__":
+    test_plot_highdpi()