Direct2D1 wave pattern with animated turbulence offset

[Odepax]

I'm trying to reproduce the following effect using Direct2D1:

I thought it would be a "simple" case of using the built-in turbulence effect, and adjusting the offset property, as the documentation says:

Offset
D2D1_TURBULENCE_PROP_OFFSET

The coordinates where the turbulence output is generated. The algorithm used to generate the Perlin noise is position dependent, so a different offset results in a different output. This property is not bounded and the units are specified in DIPs.

Note: The offset does not have the same effect as a translation because the noise function output is infinite and the function will wrap around the tile.

So I coded this simple turbulence effect:

public void OnRender(ID2D1DeviceContext g, float t) {
   using var turbulenceEffect = new Turbulence(g) {
      Offset = new Vector2(t, 0)
   };

   g.Clear(Colors.Black);
   g.DrawImage(turbulenceEffect);
}

However, the render outputs a turbulence image slowly crawling rightward, acting as if the turbulence offset was indeed a translation, unlike what I understand from the documentation quoted above.

Could it be a bug in Vortice? Is my understanding of the docs incorrect? If not, what would be the correct way to implement the desired effect?

---

Reference image source
Vortice.Direct2D1 2.4.2
.NET Target Framework: net6.0-windows10.0.19041.0

[amerkoleci]

Try to reproduce it in native and see how it behaves, then we can make a conclusion

[Odepax]

I doubt I'll have the competence to go anywhere with native. 😢

That said, SO suggests that my understanding of the doc is incorrect.