Question

In my game I’m using a powerup system, which basically works like this:

• Enemy gets killed, has random chance to drop powerup box
• Pickup powerup box to get random item

The code for giving the player a random powerup looks like this…

Type t = RandomManager.PickFromParams<Type>(typeof(PowerupInvincible), typeof(PowerupDoubleFireRate));
ply.AddPowerup<t>();

And the AddPowerup<>() method looks like this:

public void AddPowerup<T>() where T : PowerupEffect, new()
{
    var powerup = new T();

    powerup.Activate(this);
    powerups.Add(powerup);
}

Now, the problem is the ply.AddPowerup<t>() line, because it complains that it can’t find the type t:

The type or namespace name ‘t’ could not be found (are you missing a using directive or an assembly reference?)

Does anyone know if there’s a way to fix this, or if that’s not possible, show me a better way to do it? Thanks in advance!

Answer 1

It sounds like you are not using generics correctly in this instance. I’m assuming PowerupInvincible, and PowerupDoubleFireRate inherit from some PowerupBase:

PowerupBase powerUp = RandomManager.PickFromParams<PowerupBase>(typeof(PowerupInvincible), typeof(PowerupDoubleFireRate));

ply.AddPowerup(powerUp);

Then the method signature simple need to be:

public void AddPowerup(PowerupBase powerup)
{
    powerup.Activate(this);
    powerups.Add(powerup);
}

Your random manager would be responsible for choosing one of the parameters, instantiating it, and then returning the instance.