>> 16 void Camera2D::update ()
     17 {
     18     if (_change)
     19     {
     20         glm::vec3 translate (-_position.x + _screenWidth / 2, -_position.y + _screenHeight / 2, 0.0f);
     21         _cameraMatrix = glm::translate (_orthoMatrix, translate);
     22
     23         glm::vec3 scale (_scale, _scale, 0.0f);
     24         _cameraMatrix = glm::scale (glm::mat4 (1.0f), scale) * _cameraMatrix;
     25
     26         _change = false;
     27     }
     28 }