> Strokes and drop shadows (aka blurs) are all things that GPUs aren't great particularly great at. They can handle those just fine. Blurs are just inherently

> Strokes and drop shadows (aka blurs) are all things that GPUs aren't great particularly great at. They can handle those just fine. Blurs are just inherently very expensive, but GPUs are no worse at them than CPUs. In fact GPUs are way faster at blurs than CPUs. Same with filled shapes. It's not really a challenge. You have a fragment shader that knows how to essentially 'clip' to a round rect, which isn't hard, and then filling it any which way with anything is trivial.