SPIGOT-7300, #1180: Add new DamageSource API providing enhanced infor…

…mation about entity damage

nms-patches/net/minecraft/world/damagesource/DamageSource.patch

@@ -1,41 +1,93 @@
 --- a/net/minecraft/world/damagesource/DamageSource.java
 +++ b/net/minecraft/world/damagesource/DamageSource.java
-@@ -20,6 +20,38 @@
+@@ -20,6 +20,81 @@
      private final Entity directEntity;
      @Nullable
      private final Vec3D damageSourcePosition;
 +    // CraftBukkit start
-+    private boolean sweep;
-+    private boolean melting;
-+    private boolean poison;
-+
-+    public boolean isSweep() {
-+        return sweep;
-+    }
++    @Nullable
++    private org.bukkit.block.Block directBlock; // The block that caused the damage. damageSourcePosition is not used for all block damages
++    private boolean withSweep = false;
++    private boolean melting = false;
++    private boolean poison = false;
++    private Entity customCausingEntity = null; // This field is a helper for when causing entity damage is not set by vanilla
 +
 +    public DamageSource sweep() {
-+        this.sweep = true;
++        this.withSweep = true;
 +        return this;
 +    }
 +
-+    public boolean isMelting() {
-+        return melting;
++    public boolean isSweep() {
++        return this.withSweep;
 +    }
 +
 +    public DamageSource melting() {
 +        this.melting = true;
 +        return this;
 +    }
 +
-+    public boolean isPoison() {
-+        return poison;
++    public boolean isMelting() {
++        return this.melting;
 +    }
 +
 +    public DamageSource poison() {
 +        this.poison = true;
 +        return this;
 +    }
++
++    public boolean isPoison() {
++        return this.poison;
++    }
++
++    public Entity getCausingEntity() {
++        return (this.customCausingEntity != null) ? this.customCausingEntity : this.causingEntity;
++    }
++
++    public DamageSource customCausingEntity(Entity entity) {
++        DamageSource damageSource = this.cloneInstance();
++        damageSource.customCausingEntity = entity;
++        return damageSource;
++    }
++
++    public org.bukkit.block.Block getDirectBlock() {
++        return this.directBlock;
++    }
++
++    public DamageSource directBlock(net.minecraft.world.level.World world, net.minecraft.core.BlockPosition blockPosition) {
++        if (blockPosition == null || world == null) {
++            return this;
++        }
++        return directBlock(org.bukkit.craftbukkit.block.CraftBlock.at(world, blockPosition));
++    }
++
++    public DamageSource directBlock(org.bukkit.block.Block block) {
++        if (block == null) {
++            return this;
++        }
++        // Cloning the instance lets us return unique instances of DamageSource without affecting constants defined in DamageSources
++        DamageSource damageSource = this.cloneInstance();
++        damageSource.directBlock = block;
++        return damageSource;
++    }
++
++    private DamageSource cloneInstance() {
++        DamageSource damageSource = new DamageSource(this.type, this.directEntity, this.causingEntity, this.damageSourcePosition);
++        damageSource.directBlock = this.getDirectBlock();
++        damageSource.withSweep = this.isSweep();
++        damageSource.poison = this.isPoison();
++        damageSource.melting = this.isMelting();
++        return damageSource;
++    }
 +    // CraftBukkit end
 
      public String toString() {
          return "DamageSource (" + this.type().msgId() + ")";
+@@ -33,7 +108,7 @@
+         return this.causingEntity != this.directEntity;
+     }
+
+-    private DamageSource(Holder<DamageType> holder, @Nullable Entity entity, @Nullable Entity entity1, @Nullable Vec3D vec3d) {
++    public DamageSource(Holder<DamageType> holder, @Nullable Entity entity, @Nullable Entity entity1, @Nullable Vec3D vec3d) {
+         this.type = holder;
+         this.causingEntity = entity1;
+         this.directEntity = entity;

nms-patches/net/minecraft/world/damagesource/DamageSources.patch

@@ -5,8 +5,8 @@
      private final DamageSource outsideBorder;
      private final DamageSource genericKill;
 +    // CraftBukkit start
-+    public final DamageSource melting;
-+    public final DamageSource poison;
++    private final DamageSource melting;
++    private final DamageSource poison;
 
      public DamageSources(IRegistryCustom iregistrycustom) {
          this.damageTypes = iregistrycustom.registryOrThrow(Registries.DAMAGE_TYPE);
@@ -16,3 +16,20 @@
          this.inFire = this.source(DamageTypes.IN_FIRE);
          this.lightningBolt = this.source(DamageTypes.LIGHTNING_BOLT);
          this.onFire = this.source(DamageTypes.ON_FIRE);
+@@ -81,6 +87,16 @@
+         return new DamageSource(this.damageTypes.getHolderOrThrow(resourcekey), entity, entity1);
+     }
+
++    // CraftBukkit start
++    public DamageSource melting() {
++        return this.melting;
++    }
++
++    public DamageSource poison() {
++        return this.poison;
++    }
++    // CraftBukkit end
++
+     public DamageSource inFire() {
+         return this.inFire;
+     }

nms-patches/net/minecraft/world/effect/PoisonMobEffect.patch

@@ -5,7 +5,7 @@
          super.applyEffectTick(entityliving, i);
          if (entityliving.getHealth() > 1.0F) {
 -            entityliving.hurt(entityliving.damageSources().magic(), 1.0F);
-+            entityliving.hurt(entityliving.damageSources().poison, 1.0F);  // CraftBukkit - DamageSource.MAGIC -> CraftEventFactory.POISON
++            entityliving.hurt(entityliving.damageSources().poison(), 1.0F);  // CraftBukkit - DamageSource.MAGIC -> CraftEventFactory.POISON
          }
 
      }