Function GameHandleEdgeScroll

src/openrct2-ui/input/MouseInput.cpp:1589–1622

    }

    void GameHandleEdgeScroll()
    {
        WindowBase* mainWindow;
        int32_t scrollX, scrollY;

        mainWindow = WindowGetMain();
        if (mainWindow == nullptr)
            return;
        if (mainWindow->flags.has(WindowFlag::noScrolling)
            || (gLegacyScene == LegacyScene::trackDesignsManager || gLegacyScene == LegacyScene::titleSequence))
            return;
        if (mainWindow->viewport == nullptr)
            return;
        if (!ContextHasFocus())
            return;

        scrollX = 0;
        scrollY = 0;

        // Scroll left / right
        const CursorState* cursorState = ContextGetCursorState();
        if (cursorState->position.x == 0)
            scrollX = -1;
        else if (cursorState->position.x >= ContextGetWidth() - 1)
            scrollX = 1;

        // Scroll up / down
        if (cursorState->position.y == 0)
            scrollY = -1;
        else if (cursorState->position.y >= ContextGetHeight() - 1)
            scrollY = 1;

        InputScrollViewport(ScreenCoordsXY(scrollX, scrollY));
    }

    void InputScrollViewport(const ScreenCoordsXY& scrollScreenCoords)
    {