add VisualRange enter/exit notifications to Notifications

uses the radar hud's Range setting so notifications match exactly
what the radar shows

src/main/java/cc/fros/features/modules/client/NotificationsModule.java

@@ -1,11 +1,19 @@
 package cc.fros.features.modules.client;
 
+import cc.fros.Fros;
 import cc.fros.event.impl.ClientEvent;
 import cc.fros.event.system.Subscribe;
 import cc.fros.features.modules.Module;
+import cc.fros.features.modules.hud.RadarHudModule;
 import cc.fros.features.settings.Setting;
 import cc.fros.util.TextUtil;
 import cc.fros.util.chat.ChatUtil;
+import net.minecraft.client.multiplayer.ClientLevel;
+import net.minecraft.world.entity.player.Player;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
 
 import static cc.fros.util.chat.SimpleSignature.from;
 
@@ -13,6 +21,12 @@ public class NotificationsModule extends Module {
     private static final String MODULE_FORMAT = "{gray} %s %s%s";
 
     public final Setting<Boolean> moduleToggle = bool("ModuleToggle", true);
+    public final Setting<Boolean> visualRange = bool("VisualRange", true);
+
+    private final Map<UUID, String> inRange = new HashMap<>();
+    private ClientLevel lastLevel;
+    private RadarHudModule radar;
+    private boolean tracked;
 
     public NotificationsModule() {
         super("Notifications", "Displays notifications for various client events", Category.CLIENT);
@@ -36,4 +50,57 @@ public class NotificationsModule extends Module {
                 moduleState ? "{green}" : "{red}",
                 moduleState ? "on" : "off"), from(event.getFeature().getName()));
     }
+
+    @Override
+    public void onTick() {
+        if (!visualRange.getValue() || mc.player == null || mc.level == null) {
+            inRange.clear();
+            tracked = false;
+            return;
+        }
+
+        if (mc.level != lastLevel) {
+            // world change: re-baseline silently instead of notifying everyone present
+            lastLevel = mc.level;
+            tracked = false;
+            inRange.clear();
+        }
+
+        double range = getRadarRange();
+        Map<UUID, String> now = new HashMap<>();
+        for (Player player : mc.level.players()) {
+            if (player == mc.player) continue;
+            if (mc.player.distanceTo(player) <= range) {
+                now.put(player.getUUID(), player.getScoreboardName());
+            }
+        }
+
+        if (tracked) {
+            for (Map.Entry<UUID, String> entry : now.entrySet()) {
+                if (inRange.containsKey(entry.getKey())) continue;
+                notify(entry.getValue(), "{green}", "entered your visual range");
+            }
+            for (Map.Entry<UUID, String> entry : inRange.entrySet()) {
+                if (now.containsKey(entry.getKey())) continue;
+                notify(entry.getValue(), "{red}", "left your visual range");
+            }
+        }
+
+        inRange.clear();
+        inRange.putAll(now);
+        tracked = true;
+    }
+
+    private void notify(String name, String color, String message) {
+        ChatUtil.sendMessage(TextUtil.text(MODULE_FORMAT,
+                name,
+                color,
+                message), from(getName() + ":" + name));
+    }
+
+    private double getRadarRange() {
+        // stay in sync with what the radar hud actually shows
+        if (radar == null) radar = Fros.moduleManager.getModuleByClass(RadarHudModule.class);
+        return radar != null ? radar.range.getValue() : 64.0;
+    }
 }