filters-felem-01-b.svg

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The test is passed if there are four green circles visible.

Test which verifies null filters and filter regions.

Four subtests each consist of a small red circle overdrawn with a larger green circle. Filters are applied to three of the red circles, hiding them and showing the green circle.

The top left subtest has no filter applied to the circle, so the green circle is visible and the red one is not. The top right subtest applies a filter to the red circle, but there is no corresponding filter element. Thus, a null filter is applied and the red circle is not shown, allowing the green circle to be seen.

The bottom left subtest applies an empty filter element with the default filterRegion, and the bottom right subtest applies an empty filter with a non-default filterRegion. In both cases where empty filters are applied, the result of the filter is a transparent black offscreen, thus showing the green circle underneath.