Slightly optimize entity capability retrieval

Author: embeddedt

forge/src/main/java/org/embeddedt/modernfix/forge/mixin/perf/forge_cap_retrieval/LivingEntityMixin.java

@@ -0,0 +1,24 @@
+package org.embeddedt.modernfix.forge.mixin.perf.forge_cap_retrieval;
+
+import net.minecraft.core.Direction;
+import net.minecraft.world.entity.LivingEntity;
+import net.minecraftforge.common.capabilities.Capability;
+import net.minecraftforge.items.CapabilityItemHandler;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+import javax.annotation.Nullable;
+
+@Mixin(LivingEntity.class)
+public class LivingEntityMixin {
+    /**
+     * @author embeddedt (issue noted by XFactHD)
+     * @reason check capability equality before checking that entity is alive, the latter requires a lot more
+     * indirection
+     */
+    @Redirect(method = "getCapability", at = @At(value = "INVOKE", target = "Lnet/minecraft/world/entity/LivingEntity;isAlive()Z"))
+    private <T> boolean checkAliveAfterCap(LivingEntity entity, Capability<T> capability, @Nullable Direction facing) {
+        return capability == CapabilityItemHandler.ITEM_HANDLER_CAPABILITY && entity.isAlive();
+    }
+}