Actually, they calculate the winding per fragment on the GPU [0]. They require polygon tessellation only for stroking (which has no winding rule). The downside

Actually, they calculate the winding per fragment on the GPU [0]. They require polygon tessellation only for stroking (which has no winding rule). The downside of their approach is that it is memory bandwidth limited, precisely because it does the winding on the GPU instead of using CPU tessellation to avoid overlap / overdraw. Curve filling is pretty much solved with implicit curves, stencil-and-cover or scanline-intersection-sort approaches (all of which can be done in a GPU only fashion). Stroking is where things could still improve a lot as it is almost always approximated by polygons. [0]: https://developer.nvidia.com/gpu-accelerated-path-rendering https://developer.nvidia.com/gpu-accelerated-path-rendering