SteamWar/Paper
9
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix incorrect invulnerability damage reduction

Browse Source 
Fixes incorrect spigot handling of the invulnerability damage
reduction applied when an already invulnerable entity is damaged with a
larger damage amount than the initial damage.
Vanilla still damages entities even if invulnerable if the damage to be
applied is larger than the previous damage taken. In that case, vanilla
applies the difference between the previous damage taken and the
proposed damage.

Spigot's damage modifier API takes over the computation of damage
reducing effects, however spigot invokes this handling with the initial
damage before computing the difference to the previous damage amount.
This leads to the reduction values to generally be larger than expected,
as they are computed on the not-yet-reduced value.
Spigot applies these reductions after calling the EntityDamageEvent and
*then* subtracts the previous damage point, leading to the final damage
amount being smaller than expected.

This patch cannot simply call the EntityDamageEvent with the reduced
damage, as that would lead to EntityDamageEvent#getDamage() returning
the already reduced damage, which breaks its method contract.
Instead, this patch makes use of the DamageModifier API, implementing
the last-damage-reduction as a DamageModifier.
This commit is contained in:
Bjarne Koll
2024-11-11 21:35:27 +01:00
parent 318f7b2014
commit c7c3d8a9cb
2 changed files with 107 additions and 80 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
paper-server/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
View File

@@ -1218,6 +1218,11 @@ public class CraftEventFactory {
private static final Function<? super Double, Double> ZERO = Functions.constant(-0.0);
public static EntityDamageEvent handleLivingEntityDamageEvent(Entity damagee, DamageSource source, double rawDamage, double freezingModifier, double hardHatModifier, double blockingModifier, double armorModifier, double resistanceModifier, double magicModifier, double absorptionModifier, Function<Double, Double> freezing, Function<Double, Double> hardHat, Function<Double, Double> blocking, Function<Double, Double> armor, Function<Double, Double> resistance, Function<Double, Double> magic, Function<Double, Double> absorption) {
// Paper start - fix invulnerability reduction in EntityDamageEvent
return handleLivingEntityDamageEvent(damagee, source, rawDamage, freezingModifier, hardHatModifier, blockingModifier, armorModifier, resistanceModifier, magicModifier, absorptionModifier, freezing, hardHat, blocking, armor, resistance, magic, absorption, null);
}
public static EntityDamageEvent handleLivingEntityDamageEvent(Entity damagee, DamageSource source, double rawDamage, double freezingModifier, double hardHatModifier, double blockingModifier, double armorModifier, double resistanceModifier, double magicModifier, double absorptionModifier, Function<Double, Double> freezing, Function<Double, Double> hardHat, Function<Double, Double> blocking, Function<Double, Double> armor, Function<Double, Double> resistance, Function<Double, Double> magic, Function<Double, Double> absorption, java.util.function.BiConsumer<Map<DamageModifier, Double>, Map<DamageModifier, Function<? super Double, Double>>> callback) {
// Paper end - fix invulnerability reduction in EntityDamageEvent
Map<DamageModifier, Double> modifiers = new EnumMap<>(DamageModifier.class);
Map<DamageModifier, Function<? super Double, Double>> modifierFunctions = new EnumMap<>(DamageModifier.class);
modifiers.put(DamageModifier.BASE, rawDamage);
@@ -1242,6 +1247,7 @@ public class CraftEventFactory {
modifierFunctions.put(DamageModifier.MAGIC, magic);
modifiers.put(DamageModifier.ABSORPTION, absorptionModifier);
modifierFunctions.put(DamageModifier.ABSORPTION, absorption);
if (callback != null) callback.accept(modifiers, modifierFunctions); // Paper - fix invulnerability reduction in EntityDamageEvent
return CraftEventFactory.handleEntityDamageEvent(damagee, source, modifiers, modifierFunctions);
}