Add sword blocking to old combat

src/main/java/xyz/nucleoid/plasmid/api/game/common/OldCombat.java

@@ -2,17 +2,23 @@
 
 import net.minecraft.component.DataComponentTypes;
 import net.minecraft.component.type.AttributeModifierSlot;
+import net.minecraft.component.type.ConsumableComponent;
 import net.minecraft.entity.attribute.EntityAttribute;
 import net.minecraft.entity.attribute.EntityAttributeModifier;
 import net.minecraft.entity.attribute.EntityAttributes;
 import net.minecraft.item.*;
+import net.minecraft.item.consume.UseAction;
 import net.minecraft.registry.entry.RegistryEntry;
+import net.minecraft.sound.SoundEvents;
 import net.minecraft.util.Identifier;
+import net.minecraft.util.Unit;
+import xyz.nucleoid.plasmid.impl.component.PlasmidDataComponentTypes;
 
 /**
  * A utility class that allows old-style 1.8 combat to be applied to any given {@link ItemStack}.
  * <p>
  * This works by modifying the damage and attack speed attributes to match their 1.8 levels.
+ * In addition, sword blocking is reinstated.
  */
 public final class OldCombat {
     private static final RegistryEntry<EntityAttribute> DAMAGE_ATTRIBUTE = EntityAttributes.ATTACK_DAMAGE;
@@ -37,14 +43,31 @@ public final class OldCombat {
     private static final int SWORD_BASE_DAMAGE = 3;
 
     public static ItemStack applyTo(ItemStack stack) {
+        stack.set(PlasmidDataComponentTypes.OLD_COMBAT, Unit.INSTANCE);
+
+        if (stack.getItem() instanceof SwordItem) {
+            stack.set(DataComponentTypes.CONSUMABLE, ConsumableComponent.builder()
+                .consumeSeconds(Float.MAX_VALUE)
+                .useAction(UseAction.BLOCK)
+                .sound(RegistryEntry.of(SoundEvents.INTENTIONALLY_EMPTY))
+                .consumeParticles(false)
+                .build());
+        }
+
+        applyAttributeModifiersTo(stack);
+
+        return stack;
+    }
+
+    private static void applyAttributeModifiersTo(ItemStack stack) {
         if (!stack.contains(DataComponentTypes.TOOL)) {
-            return stack;
+            return;
         }
 
         var material = getToolMaterial(stack);
 
         if (material == null) {
-            return stack;
+            return;
         }
 
         var defaultModifiers = stack.get(DataComponentTypes.ATTRIBUTE_MODIFIERS);
@@ -63,7 +86,6 @@ public static ItemStack applyTo(ItemStack stack) {
         }
 
         stack.set(DataComponentTypes.ATTRIBUTE_MODIFIERS, defaultModifiers);
-        return stack;
     }
 
     private static EntityAttributeModifier createSpeedModifier() {

src/main/java/xyz/nucleoid/plasmid/impl/Plasmid.java

@@ -39,6 +39,7 @@
 import xyz.nucleoid.plasmid.impl.portal.game.SingleGamePortalConfig;
 import xyz.nucleoid.plasmid.impl.command.*;
 import xyz.nucleoid.plasmid.impl.compatibility.TrinketsCompatibility;
+import xyz.nucleoid.plasmid.impl.component.PlasmidDataComponentTypes;
 import xyz.nucleoid.plasmid.impl.portal.menu.*;
 
 public final class Plasmid implements ModInitializer {
@@ -67,6 +68,8 @@ public void onInitialize() {
             throw new GameOpenException(Text.translatable("text.plasmid.map.open.invalid_game", id != null ? id.toString() : context.game()));
         });
 
+        PlasmidDataComponentTypes.register();
+
         this.registerCallbacks();
 
         if (FabricLoader.getInstance().isModLoaded("trinkets")) {

src/main/java/xyz/nucleoid/plasmid/impl/component/PlasmidDataComponentTypes.java

@@ -0,0 +1,26 @@
+package xyz.nucleoid.plasmid.impl.component;
+
+import eu.pb4.polymer.core.api.other.PolymerComponent;
+import net.minecraft.component.ComponentType;
+import net.minecraft.registry.Registries;
+import net.minecraft.registry.Registry;
+import net.minecraft.util.Identifier;
+import net.minecraft.util.Unit;
+import xyz.nucleoid.plasmid.impl.Plasmid;
+
+public final class PlasmidDataComponentTypes {
+    private PlasmidDataComponentTypes() {
+    }
+
+    public static final ComponentType<Unit> OLD_COMBAT = register("old_combat", ComponentType.<Unit>builder()
+            .codec(Unit.CODEC)
+            .build());
+
+    private static <T> ComponentType<T> register(String path, ComponentType<T> type) {
+        return Registry.register(Registries.DATA_COMPONENT_TYPE, Identifier.of(Plasmid.ID, path), type);
+    }
+
+    public static void register() {
+        PolymerComponent.registerDataComponent(OLD_COMBAT);
+    }
+}

src/main/java/xyz/nucleoid/plasmid/mixin/game/common/LivingEntityMixin.java

@@ -0,0 +1,75 @@
+package xyz.nucleoid.plasmid.mixin.game.common;
+
+import com.llamalad7.mixinextras.injector.wrapoperation.Operation;
+import com.llamalad7.mixinextras.injector.wrapoperation.WrapOperation;
+import com.llamalad7.mixinextras.sugar.Local;
+import com.llamalad7.mixinextras.sugar.ref.LocalFloatRef;
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.damage.DamageSource;
+import net.minecraft.item.Item;
+import net.minecraft.item.ItemStack;
+import net.minecraft.item.Items;
+import net.minecraft.item.ShieldItem;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Constant;
+import org.spongepowered.asm.mixin.injection.ModifyConstant;
+import xyz.nucleoid.plasmid.impl.component.PlasmidDataComponentTypes;
+
+@Mixin(LivingEntity.class)
+public class LivingEntityMixin {
+    @Shadow
+    @Final
+    private ItemStack activeItemStack;
+
+    @WrapOperation(
+            method = "blockedByShield",
+            at = @At(
+                    value = "INVOKE",
+                    target = "Lnet/minecraft/item/ItemStack;getItem()Lnet/minecraft/item/Item;"
+            )
+    )
+    private Item allowOldCombatSwordBlocking(ItemStack stack, Operation<Item> operation) {
+        // Allow fulfilling the instanceof ShieldItem check
+        if (stack.contains(PlasmidDataComponentTypes.OLD_COMBAT)) {
+            return Items.SHIELD;
+        }
+
+        return operation.call(stack);
+    }
+
+    @WrapOperation(
+            method = "damage",
+            at = @At(
+                    value = "INVOKE",
+                    target = "Lnet/minecraft/entity/LivingEntity;blockedByShield(Lnet/minecraft/entity/damage/DamageSource;)Z"
+            )
+    )
+    private boolean applyHalfDamageFromSwordBlocking(LivingEntity entity, DamageSource source, Operation<Boolean> operation, @Local(ordinal = 0, argsOnly = true) LocalFloatRef amount) {
+        if (operation.call(entity, source)) {
+            ItemStack stack = entity.getBlockingItem();
+
+            if (!stack.contains(PlasmidDataComponentTypes.OLD_COMBAT) || stack.getItem() instanceof ShieldItem) {
+                return true;
+            }
+
+            amount.set(Math.max(0, (amount.get() / 2) - 0.5f));
+        }
+
+        return false;
+    }
+
+    @ModifyConstant(
+            method = "getBlockingItem",
+            constant = @Constant(intValue = 5)
+    )
+    private int allowInstantSwordBlocking(int original) {
+        if (!this.activeItemStack.contains(PlasmidDataComponentTypes.OLD_COMBAT) || this.activeItemStack.getItem() instanceof ShieldItem) {
+            return original;
+        }
+
+        return 0;
+    }
+}

src/main/resources/plasmid.mixins.json

@@ -8,6 +8,7 @@
     "chat.PlayerEntityMixin",
     "chat.PlayerListS2CPacketEntryAccessor",
     "chat.ServerPlayerEntityMixin",
+    "game.common.LivingEntityMixin",
     "game.portal.EntityMixin",
     "game.portal.SignBlockEntityMixin",
     "game.rule.EquippableComponentMixin",