Merge pull request #9793 from Morph1984/borderless-hidpi

main: Fix borderless fullscreen for high dpi scaled displays
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liamwhite 2023-02-14 09:11:15 -05:00 committed by GitHub
commit d87db919f9
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@ -3167,8 +3167,20 @@ void GMainWindow::ShowFullscreen() {
window->hide();
window->setWindowFlags(window->windowFlags() | Qt::FramelessWindowHint);
const auto screen_geometry = GuessCurrentScreen(window)->geometry();
// NB: On Windows, a borderless window will be treated the same as exclusive fullscreen
// when the window geometry matches the physical dimensions of the screen.
// However, with High DPI scaling, when the devicePixelRatioF() is > 1, the borderless
// window apparently is not treated as exclusive fullscreen and functions correctly.
// One can verify and replicate this behavior by using a high resolution (4K) display,
// and switching between 100% and 200% scaling in Windows' display settings.
// At 100%, without the addition of 1, it is treated as exclusive fullscreen.
// At 200%, with or without the addition of 1, it is treated as borderless windowed.
// Therefore, we can use (read: abuse) this difference in behavior to fix this issue for
// those with higher resolution displays when the Qt scaling ratio is > 1.
// Should this behavior be changed in the future, please revisit this workaround.
const bool must_add_one = devicePixelRatioF() == 1.0f;
window->setGeometry(screen_geometry.x(), screen_geometry.y(), screen_geometry.width(),
screen_geometry.height() + 1);
screen_geometry.height() + (must_add_one ? 1 : 0));
window->raise();
window->showNormal();
};