Damage calculation over area

The damage fades in linear regression from the center to the edge of the impact area, in cell-sized steps. PercentAtMax determines the percentage of damage left at the very edge of the affected area.

Example:

Imagine three identical targets, the first one (A) placed at the impact point, the second one (B) at the edge of the impact zone, and the third (C) in the middle of them.

Upon detonation of a warhead with stats:

PercentAtMax=1.0
CellSpread=10

Target A receives 100% original damage, Target B receives 100%, and Target C receives 100% as well.

If a different warhead is detonated, with stats:

PercentAtMax=0.02
CellSpread=10

, Target A receives 100% of the original damage, Target B receives 2%, and Target C receives 51% (linear average = (100 + 2) / 2).