Infrastructure for Energy Shield type Armor

[John-Candlebury]

Summary

Infrastructure "Add a new Energy Shield type of armor for use in mods."

Purpose of change

I mostly want this for Aftershock energy shields. but it has clear applications for the rest of our magic mods.

Describe the solution

Energy shields work just like normal armor. The only difference is that they dont degrade with attacks, they instead have a health pool, tracked by the dialogue variable ENERGY_SHIELD_HP that gets depleted by blocked damage. With the shield instantly breaking down when it reaches zero. Energy shields take 1 hp damage for every point of damage they block.

They also have a second variable ENERGY_SHIELD_MAX_HP if you want to make the item regen HP using EOCs.

You'll need to both define an energy_shield_max_hp > 0 and give an item the ENERGY_SHIELD flag if you want it to behave like a shield.

Describe alternatives you've considered

Increasing the hardcoded behaviors of the shields but I think the ability to modify their Hp variables with EOCs is enough.

Testing

Spawn and wear a weak energy shield item, which protects only agains ballistic damage. Get hit by a zombie and notice no degradation. Get shot by a MP5 turret, recieve no damage and watch the shield collapse.

[Maleclypse]

I can't understand how ENERGY_SHIELD_MAX_HP works from the documentation. Probably needs an example?

[John-Candlebury]

It doesnt do anything but record the max hp if you want a regen HP eoc for the shield. (which you need to code yourself)

[GuardianDll]

Writing it here so i won't forget about it, but i have #77515, so whoever pr will be merged last (and i suspect your PR would be merged first) would need to update the code