Is FillRule affects performance?

[ya-ponchik]

is there a difference between them?

[AngusJohnson]

Yes, it does.

For example, given a complex polygon of say 20 random edges:
EvenOdd filling will generally created many more edges in the solution that the same polygon using NonZero filling.
And it's computationally time costly tracking all these extra edges.

Polygon:

EvenOdd:

NonZero:

[ya-ponchik]

My subject polygons are non-self-intersecting polygons with holes, and the clip is a single polygon. So which FillRule is the best fit (of all of them)? I don't see any visual difference between the modes. This is what my use case looks like:

bandicam.2023-02-01.19-17-53-618.mp4

[AngusJohnson]

My subject polygons are non-self-intersecting polygons with holes, and the clip is a single polygon. So which FillRule is the best fit (of all of them)?

I really don't think it would matter, but can't you profile it and see for yourself? 😁.

[ya-ponchik]

My subject polygons are non-self-intersecting polygons with holes, and the clip is a single polygon. So which FillRule is the best fit (of all of them)?

I really don't think it would matter, but can't you profile it and see for yourself? 😁.

I tried very straight forward. On right click:

void level_geometry::poly_destruction(const double x, const double y, const double r)
{
    Clipper2Lib::Paths64 clip;
    clip.push_back(approximate_circle(x, y, r));


    console.call<void>("time", emscripten::val("EvenOdd"));
    for (size_t i = 0; i < 200; i++)
    {
        auto result = Difference(m_rings, clip, Clipper2Lib::FillRule::EvenOdd);
    }
    console.call<void>("timeEnd", emscripten::val("EvenOdd"));

    console.call<void>("time", emscripten::val("Positive"));
    for (size_t i = 0; i < 200; i++)
    {
        auto result = Difference(m_rings, clip, Clipper2Lib::FillRule::Positive);
    }
    console.call<void>("timeEnd", emscripten::val("Positive"));

    console.call<void>("time", emscripten::val("NonZero"));
    for (size_t i = 0; i < 200; i++)
    {
        auto result = Difference(m_rings, clip, Clipper2Lib::FillRule::NonZero);
    }
    console.call<void>("timeEnd", emscripten::val("NonZero"));

    console.call<void>("log", emscripten::val("==========================="));

    m_rings = Difference(m_rings, clip, Clipper2Lib::FillRule::NonZero);
}

Results: