Do not send thunder strength if not raining (#5031)

* Do not send thunder strength if not raining

* Address review

* Minor optimization

core/src/main/java/org/geysermc/geyser/session/GeyserSession.java

@@ -572,14 +572,16 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
     private float walkSpeed;
 
     /**
-     * Caches current rain status.
+     * Caches current rain strength.
+     * Value between 0 and 1.
      */
-    private boolean raining = false;
+    private float rainStrength = 0.0f;
 
     /**
-     * Caches current thunder status.
+     * Caches current thunder strength.
+     * Value between 0 and 1.
      */
-    private boolean thunder = false;
+    private float thunderStrength = 0.0f;
 
     /**
      * Stores a map of all statistics sent from the server.
@@ -2023,23 +2025,30 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
      * @param strength value between 0 and 1
      */
     public void updateRain(float strength) {
-        this.raining = strength > 0;
+        boolean wasRaining = isRaining();
+        this.rainStrength = strength;
 
         LevelEventPacket rainPacket = new LevelEventPacket();
-        rainPacket.setType(this.raining ? LevelEvent.START_RAINING : LevelEvent.STOP_RAINING);
+        rainPacket.setType(isRaining() ? LevelEvent.START_RAINING : LevelEvent.STOP_RAINING);
         rainPacket.setData((int) (strength * 65535));
         rainPacket.setPosition(Vector3f.ZERO);
+        sendUpstreamPacket(rainPacket);
 
-        if (this.raining) {
+        // Keep thunder in sync with rain when starting/stopping a storm
-            sendUpstreamPacket(rainPacket);
+        if ((wasRaining != isRaining()) && isThunder()) {
+            if (isRaining()) {
+                LevelEventPacket thunderPacket = new LevelEventPacket();
+                thunderPacket.setType(LevelEvent.START_THUNDERSTORM);
+                thunderPacket.setData((int) (this.thunderStrength * 65535));
+                thunderPacket.setPosition(Vector3f.ZERO);
+                sendUpstreamPacket(thunderPacket);
             } else {
-            // The bedrock client might ignore this packet if it is sent in the same tick as another rain packet
+                LevelEventPacket thunderPacket = new LevelEventPacket();
-            // https://github.com/GeyserMC/Geyser/issues/3679
+                thunderPacket.setType(LevelEvent.STOP_THUNDERSTORM);
-            scheduleInEventLoop(() -> {
+                thunderPacket.setData(0);
-                if (!this.raining) {
+                thunderPacket.setPosition(Vector3f.ZERO);
-                    sendUpstreamPacket(rainPacket);
+                sendUpstreamPacket(thunderPacket);
             }
-            }, 100, TimeUnit.MILLISECONDS);
         }
     }
 
@@ -2050,24 +2059,28 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
      * @param strength value between 0 and 1
      */
     public void updateThunder(float strength) {
-        this.thunder = strength > 0;
+        this.thunderStrength = strength;
+
+        // Do not send thunder packet if not raining
+        // The bedrock client will start raining automatically when updating thunder strength
+        // https://github.com/GeyserMC/Geyser/issues/3679
+        if (!isRaining()) {
+            return;
+        }
 
         LevelEventPacket thunderPacket = new LevelEventPacket();
-        thunderPacket.setType(this.thunder ? LevelEvent.START_THUNDERSTORM : LevelEvent.STOP_THUNDERSTORM);
+        thunderPacket.setType(isThunder() ? LevelEvent.START_THUNDERSTORM : LevelEvent.STOP_THUNDERSTORM);
         thunderPacket.setData((int) (strength * 65535));
         thunderPacket.setPosition(Vector3f.ZERO);
+        sendUpstreamPacket(thunderPacket);
+    }
 
-        if (this.thunder) {
+    public boolean isRaining() {
-            sendUpstreamPacket(thunderPacket);
+        return this.rainStrength > 0;
-        } else {
-            // The bedrock client might ignore this packet if it is sent in the same tick as another thunderstorm packet
-            // https://github.com/GeyserMC/Geyser/issues/3679
-            scheduleInEventLoop(() -> {
-                if (!this.thunder) {
-                    sendUpstreamPacket(thunderPacket);
-                }
-            }, 100, TimeUnit.MILLISECONDS);
     }
+
+    public boolean isThunder() {
+        return this.thunderStrength > 0;
     }
 
     @Override