Direct2D has some complex algorithms because it was designed for high-quality antialiased rasterization on DX9-class hardware, particularly tesselation, and suitable not only for vector graphics but also text glyphs. This bleeds over into the API, which is quite complex and somewhat annoying at times. It revives the GDI-style interface of needing to create and select a solid brush object instead of just passing a color, and drawing text with colored spans is embarrassingly involved (it involves writing a custom rendering bridge between Direct2D and DirectWrite).
The other problem is that Wine has only implemented a minimal amount of the Direct2D API to get specific programs working that aren't heavy graphics programs. Two major omissions, the last time I looked, were that Wine's implementation does not support antialiasing at all, and its ArcTo() draws a line.
The other problem is that Wine has only implemented a minimal amount of the Direct2D API to get specific programs working that aren't heavy graphics programs. Two major omissions, the last time I looked, were that Wine's implementation does not support antialiasing at all, and its ArcTo() draws a line.