PaperMC/paper-server/patches/sources/net/minecraft/world/level/EntityGetter.java.patch

--- a/net/minecraft/world/level/EntityGetter.java
+++ b/net/minecraft/world/level/EntityGetter.java
@@ -71,6 +71,11 @@
         }
     }
 
+    // Paper start - Affects Spawning API
+    default @Nullable Player findNearbyPlayer(Entity entity, double maxDistance, @Nullable Predicate<Entity> predicate) {
+        return this.getNearestPlayer(entity.getX(), entity.getY(), entity.getZ(), maxDistance, predicate);
+    }
+    // Paper end - Affects Spawning API
     @Nullable
     default Player getNearestPlayer(double x, double y, double z, double maxDistance, @Nullable Predicate<Entity> targetPredicate) {
         double d = -1.0;
@@ -100,6 +105,20 @@
         return this.getNearestPlayer(x, y, z, maxDistance, predicate);
     }
 
+    // Paper start - Affects Spawning API
+    default boolean hasNearbyAlivePlayerThatAffectsSpawning(double x, double y, double z, double range) {
+        for (Player player : this.players()) {
+            if (EntitySelector.PLAYER_AFFECTS_SPAWNING.test(player)) { // combines NO_SPECTATORS and LIVING_ENTITY_STILL_ALIVE with an "affects spawning" check
+                double distanceSqr = player.distanceToSqr(x, y, z);
+                if (range < 0.0D || distanceSqr < range * range) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+    // Paper end - Affects Spawning API
+
     default boolean hasNearbyAlivePlayer(double x, double y, double z, double range) {
         for (Player player : this.players()) {
             if (EntitySelector.NO_SPECTATORS.test(player) && EntitySelector.LIVING_ENTITY_STILL_ALIVE.test(player)) {