static void Prefix(PLPostProcessVignette __instance, out float __state)
        {
            float multiplier = 0.5f;

            __instance.VignetteAmount *= multiplier;
            __instance.VignetteSize   *= multiplier;
            __instance.ExposureBoost  *= multiplier;
            __state = multiplier;
        }
 static void Postfix(PLPostProcessVignette __instance, float __state)
 {
     __instance.VignetteAmount *= 1 / __state;
     __instance.VignetteSize   *= 1 / __state;
     __instance.ExposureBoost  *= 1 / __state;
 }