Mismatch between planet explosion code, comments, and documentation

docs

When a planet dies, it explodes, dealing damage to any ships or planets within 10 units of the planet surface. The damage scales linearly with distance from the surface, beginning at 255 damage when adjacent to the planet and ending at 51 damage if 5 units away.

code

Logic is here: https://github.com/HaliteChallenge/Halite-II/blob/11b7d6c1abc588d0de250b854d9d47963077b786/environment/core/Halite.cpp#L71-L84

Where distance is center of planet to closest edge of the target (ship or other planet), distance_from_crust is the distance from planet crust to the closest edge of the target, and max_distance is the higher of the docking radius constant (4) or the planet’s radius.

Only ships within max_distance are considered for this method, so any damage scaling beyond the planet radius (or docking distance) is ignored.

I think the damage is closer to this (but could be wrong, can somebody verify?)

radius	distance	damage
2	0	1275
2	2	1211.25
2	4	1147.5
4	0	1275
4	4	1147.5
8	0	1275
8	4	1211.25
8	8	1147.5

[Billiam]

I think this new logic is backwards:

const auto damage = min_damage + (distance_from_crust / max_distance) * (max_damage - min_damage);

At a close distance (1) to a planet with a radius of 4

auto_damage = 127.5 + (1 / 4) * (1275 - 127.5)  # 414.375 damage

At the maximum distance

auto_damage = 127.5 + (4 / 4) * (1275 - 127.5) # 1275.0 damage

I think you’d want

const auto damage = min_damage + (1 - distance_from_crust / max_distance) * (max_damage - min_damage);

[lidavidm]

@Billiam good catch, my mistake.