Function screen

src/fl/fx/2d/animartrix_detail/engine_core.h:155–157

inline float add(float &a, float &b) { return a + b; }

inline float screen(float &a, float &b) {
    return (1 - (1 - a / 255.f) * (1 - b / 255.f)) * 255.f;
}

inline float colordodge(float &a, float &b) { return (a / (255.f - b)) * 255.f; }