gistfile1.cpp

sf::Vector3f x(start_color.r, start_color.g, start_color.b);
  	sf::Vector3f y(end_color.r, end_color.g, end_color.b);

		const float max_time = fade_duration; // == 1.0f
		const float current_time = fade_timer.restart().asSeconds();
		const float a = std::min(1.0f, std::max(0.0f, current_time - max_time));
		sf::Vector3f interp = x * (1 - a) + y * a;