Add rule to make the World Border update with ticks instead of real time (#1550)

src/main/java/carpet/mixins/WorldBorder_tickMixin.java

@@ -0,0 +1,25 @@
+package carpet.mixins;
+
+import carpet.CarpetSettings;
+import carpet.patches.TickSyncedBorderExtent;
+import net.minecraft.world.level.border.WorldBorder;
+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.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(WorldBorder.class)
+public class WorldBorder_tickMixin
+{
+    @Shadow private WorldBorder.BorderExtent extent;
+
+    @Inject(method = "lerpSizeBetween", at = @At(value = "INVOKE", target = "Lnet/minecraft/world/level/border/WorldBorder;getListeners()Ljava/util/List;"))
+    private void getExtent(double d, double e, long l, CallbackInfo ci)
+    {
+        if (d != e && CarpetSettings.tickSyncedWorldBorders)
+        {
+            this.extent = new TickSyncedBorderExtent((WorldBorder) (Object) this, l, d, e);
+        }
+    }
+}