Text render error

I created a demo to render the letter 'H.' The 'H' rendered by QtRendering doesn’t have sharp corners; the edges are rounded instead. NativeRendering appears fine, while CurveRendering shows a ring of sub-pixels along the edges. You can check the screenshots in the attachment: the red one is QtRendering, the blue one is NativeRendering, and the green one is CurveRendering.

test_text_render.zip