Function WindowZoomSet

src/openrct2/interface/Window.cpp:436–489

    }

    void WindowZoomSet(WindowBase& w, ZoomLevel zoomLevel, bool atCursor)
    {
        Viewport* v = w.viewport;
        if (v == nullptr)
            return;

        zoomLevel = std::clamp(zoomLevel, ZoomLevel::min(), ZoomLevel::max());
        if (v->zoom == zoomLevel)
            return;

        const ZoomLevel previousZoomLevel = v->zoom;

        // Zoom in
        while (v->zoom > zoomLevel)
        {
            v->zoom--;
            w.savedViewPos.x += v->ViewWidth() / 2;
            w.savedViewPos.y += v->ViewHeight() / 2;
        }

        // Zoom out
        while (v->zoom < zoomLevel)
        {
            v->zoom++;
            w.savedViewPos.x -= v->ViewWidth() / 4;
            w.savedViewPos.y -= v->ViewHeight() / 4;
        }

        if (Config::Get().general.zoomToCursor && atCursor)
        {
            const auto mouseCoords = ContextGetCursorPositionScaled() - v->pos;
            const int32_t diffX = (mouseCoords.x - (zoomLevel.ApplyInversedTo(v->ViewWidth()) / 2));
            const int32_t diffY = (mouseCoords.y - (zoomLevel.ApplyInversedTo(v->ViewHeight()) / 2));
            if (previousZoomLevel > zoomLevel)
            {
                w.savedViewPos.x += zoomLevel.ApplyTo(diffX);
                w.savedViewPos.y += zoomLevel.ApplyTo(diffY);
            }
            else
            {
                w.savedViewPos.x -= previousZoomLevel.ApplyTo(diffX);
                w.savedViewPos.y -= previousZoomLevel.ApplyTo(diffY);
            }
        }

        v->viewPos.x = w.savedViewPos.x;
        v->viewPos.y = w.savedViewPos.y;

        // HACK: Prevents the redraw from failing when there is
        // a window on top of the viewport.
        auto* windowMgr = Ui::GetWindowManager();
        windowMgr->BringToFront(w);
        w.invalidate();
    }

    /**
     * Splits a drawing of a window into regions that can be seen and are not hidden