Modifying changes to a $variable across the whole game

Question

I'm experimenting with an aggression meter.  This tracks how violently the PC or an NPC can act – if $pc.aggression lt 10 he might have the option to shove someone or shout a violent insult; if $pc.aggression gt 90 he might unlock the option to drive his thumbs into a foe's eyes.

So far, so good!  Now, I'd like to introduce some game-wide modifiers.  For example, if $pcTraits.contains("berserker"), I'd like all increases to $pc.aggression to be doubled.

Now I could do this with a lot of <<if>> statements, but I'm coming to appreciate the limitations of such a brute-force approach – it would require lots of duplication of code.  Is there a smarter way to tell the game to double any increases to $pc.aggression if $pcTraits.contains("berserker")?

Answer 1

I recommend using widgets to cut down on repeated code. That's 90% of the answer you're probably looking for. All following examples will do so, and the widgets are used like so: 

<<addAggression (number)>>

E.g. 
<<addAgression 4>>
/% adds 4 to aggression. if berserker trait is chosen, adds 8 %/

There's a few approaches you could try. Here's some of them. You could: 

• Use a modifier. 

/% in StoryInit, set $aggressionMod to 1; when the perk is selected increase the mod to 2 %/

<<widget "addAggression">>\
    <<silently>>
        <<set _increase to $args[0] * $aggressionMod>>
        <<set $pc.aggression += _increase>>
    <</silently>>\
<</widget>>

• Use the ternary operator (?). Works like an if/else. 

<<widget "addAggression">>\
    <<silently>>
        <<set _increase to ($pcTraits.includes("berserker")) ? ($args[0] * 2) : $args[0]>>
        <<set $pc.aggression += _increase>>
    <</silently>>\
<</widget>>

Note the use of "includes" instead of "contains". Contains is deprecated. 

• Use <<if>> macros as you have been, but use widgets as shown above. 

<<widget "addAggression">>\
    <<silently>>
        <<set _increase to $args[0]>>
        <<if $pcTraits.includes("berserker")>>
            <<set _increase *= 2>>
        <</if>>
        <<set $pc.aggression += _increase>>
    <</silently>>\
<</widget>>

They all work fine, which one you use will likely depend on preference. 

Comments

Thanks, Chapel.  Your idea of creating an <<addAggression>> widget is exactly the conceptual breakthrough I was lacking.

---

Chapel, in your third widget example, what does this line do?

  <<set _increase to $args[0]>>

---

Pretty much nothing. I tend to like to "unpack" the $args array into temp variables so they can have more appropriate names, that's all. I also like to do it first, so I know $args[0], i.e. the first argument, is the amount of the increase. Makes it easier for very complicated widgets with potentially a lot of arguments, but is totally unnecessary in all the examples above. More a habit for me, so my apologies if it's confusing.

---

Thanks, Chapel.  :-)