gfx backend mouse input is scaled by 2 on Mac

[Timmmm]

This must be a hidpi issue, but on Mac on a retina display the mouse input positions are all doubled (or equivalently, the output image is doubled).

That is, if you click 1cm to the right the left window edge, the click will be received by the widget 2cm to the right of the window edge. The doubling is relative to the window, not the screen. Hope that's clear!

[snuk182]

Fixing something Mac-related without a Mac is challenging. I will give it a try. Thanks for the ticket!

[snuk182]

As a workaround I may propose the following for mouse input processing:

glutin::WindowEvent::CursorMoved { position: (x, y), .. } => {
                        mx = (x as f64 * window.hidpi_factor()) as i32;
                        my = (y as f64 * window.hidpi_factor()) as i32;
                        ctx.input_motion(mx, my);
}

[snuk182]

Have recently accepted a version-raise PR that may solve this. Couldn't you please check?