Screen size is wrong for multiples above 1x with a screen gap

[rzumer]

There are black bars to the left and right of the screen when picking 2x resolution on my end.

This seems to be an "inverse" of #553. Rather than the gap not scaling, the gap now scales and there is not enough vertical space for the screens to fill the frame.

[Arisotura]

I believe this is the same sort of issue as #697

[tuzepoito]

I have encountered the same issue on Windows 8. I don't think the problem is related to HiDPI. Rather, it seems the option "Config > Screen size" does take the screen gap (in "Config > Screen gap") into account, but incorrectly.

For instance, when the Screen gap is 0, and I set the screen size as 2x, I get a window size of 512x768, which is the expected result.

However, when I set "Screen gap" as 8, and then "Screen size" as 2x, here is what I get:

There are black borders on the left and the right of the screens.

More precisely, the window height is set to 776 (768 + 8) pixels. It seems "Screen size" option assumes that the screen gap is 8 pixels, but actually it is larger, because the screen gap is scaled as the viewport scales. Therefore, the actual viewport size is smaller than expected, resulting in borders on the left and the right of the window. The effect is more present as the screen gap size is larger.

To me, there are two solutions:

• Solution 1: keep a constant screen gap no matter the scaling. It that example, that would mean a screen size of 512x776 (776 = 768 + 8)

• Solution 2: let "Screen size" take into account the scaling of the screen gap. In that example, that would mean a screen size of 512x784 (784 = 768 + 16)

Personally, I get this result by setting Screen size "2x", and then manually setting the window height.