【C++】OpenGL座標與物理屏幕座標互轉

template<typename type>
class point
{
public:
    type x = 0;
    type y = 0;
};

float m_half_width = 400.0f; // 屏幕的一半寬
float m_half_height = 300.0f; // 屏幕的一半高

point<float> map_to_window(const point<int> &pos) const
{
    point<float> new_pos;
    new_pos.x = pos.x / m_half_width - 1.0f;
    new_pos.y = 1.0f - pos.y / m_half_height;
    return new_pos;
}

point<int> map_from_window(const point<float> &pos) const
{
    point<int> new_pos;
    new_pos.x = static_cast<int>(pos.x * m_half_width + m_half_width + 0.5f);
    new_pos.y = static_cast<int>(m_half_height - pos.y * m_half_height + 0.5f);
    return new_pos;
}