Method render

example/lottieperf.cpp:47–51

        _surface = rlottie::Surface(_buffer.get(), 100, 100, 100 * 4);
    }
    void render()
    {
        if (_cur >= _frames) _cur = 0;
        _animation->renderSync(_cur++, _surface);
    }
    void renderAsync()
    {
        if (_cur >= _frames) _cur = 0;