Function AdjustGUIZoom

src/gfx.cpp:1818–1856

* Resolve GUI zoom level and adjust GUI to new zoom, if auto-suggestion is requested. * @param automatic Set if the change is occurring due to OS DPI scaling being changed. * @returns true when the zoom level has changed, caller must call ReInitAllWindows(true) * after resizing the application's window/buffer. */

 * after resizing the application's window/buffer.
 */
bool AdjustGUIZoom(bool automatic)
{
	if (VideoDriver::GetInstance() == nullptr) return false;

	ZoomLevel old_gui_zoom = _gui_zoom;
	ZoomLevel old_font_zoom = _font_zoom;
	int old_scale = _gui_scale;
	UpdateGUIZoom();
	if (old_scale == _gui_scale && old_gui_zoom == _gui_zoom) return false;

	/* Update cursors if sprite zoom level has changed. */
	if (old_gui_zoom != _gui_zoom) {
		VideoDriver::GetInstance()->ClearSystemSprites();
		UpdateCursorSize();
	}
	if (old_font_zoom != _font_zoom) {
		GfxClearFontSpriteCache();
	}
	FontCache::ClearFontCaches(FONTSIZES_ALL);
	LoadStringWidthTable();

	SetupWidgetDimensions();
	UpdateAllVirtCoords();

	/* Adjust all window sizes to match the new zoom level, so that they don't appear
	   to move around when the application is moved to a screen with different DPI. */
	auto zoom_shift = old_gui_zoom - _gui_zoom;
	for (Window *w : Window::Iterate()) {
		if (automatic) {
			w->left   = (w->left   * _gui_scale) / old_scale;
			w->top    = (w->top    * _gui_scale) / old_scale;
		}
		if (w->viewport != nullptr) {
			w->viewport->zoom = Clamp(w->viewport->zoom - zoom_shift, _settings_client.gui.zoom_min, _settings_client.gui.zoom_max);
		}
	}

	return true;
}

void ChangeGameSpeed(bool enable_fast_forward)
{