Simplified backend input prediction.

battle_srv/models/player.go

@@ -46,9 +46,10 @@ type Player struct {
 	TutorialStage int       `db:"tutorial_stage"`
 
 	// other in-battle info fields
-	LastSentInputFrameId int32
-	AckingFrameId        int32
-	AckingInputFrameId   int32
+	LastReceivedInputFrameId int32
+	LastSentInputFrameId     int32
+	AckingFrameId            int32
+	AckingInputFrameId       int32
 }
 
 func ExistPlayerByName(name string) (bool, error) {

battle_srv/models/room.go

@@ -128,7 +128,7 @@ type Room struct {
 	EffectivePlayerCount                   int32
 	DismissalWaitGroup                     sync.WaitGroup
 	InputsBuffer                           *battle.RingBuffer // Indices are STRICTLY consecutive
-	InputsBufferLock                       sync.Mutex         // Guards [InputsBuffer, LatestPlayerUpsyncedInputFrameId, LastAllConfirmedInputFrameId, LastAllConfirmedInputList, LastAllConfirmedInputFrameIdWithChange]
+	InputsBufferLock                       sync.Mutex         // Guards [InputsBuffer, LatestPlayerUpsyncedInputFrameId, LastAllConfirmedInputFrameId, LastAllConfirmedInputList, LastAllConfirmedInputFrameIdWithChange, LastIndividuallyConfirmedInputList, player.LastReceivedInputFrameId]
 	RenderFrameBuffer                      *battle.RingBuffer // Indices are STRICTLY consecutive
 	LatestPlayerUpsyncedInputFrameId       int32
 	LastAllConfirmedInputFrameId           int32
@@ -148,7 +148,8 @@ type Room struct {
 	TmxPointsMap   StrToVec2DListMap
 	TmxPolygonsMap StrToPolygon2DListMap
 
-	rdfIdToActuallyUsedInput map[int32]*pb.InputFrameDownsync
+	rdfIdToActuallyUsedInput           map[int32]*pb.InputFrameDownsync
+	LastIndividuallyConfirmedInputList []uint64
 }
 
 func (pR *Room) updateScore() {
@@ -172,6 +173,7 @@ func (pR *Room) AddPlayerIfPossible(pPlayerFromDbInit *Player, session *websocke
 	pPlayerFromDbInit.AckingFrameId = -1
 	pPlayerFromDbInit.AckingInputFrameId = -1
 	pPlayerFromDbInit.LastSentInputFrameId = MAGIC_LAST_SENT_INPUT_FRAME_ID_NORMAL_ADDED
+	pPlayerFromDbInit.LastReceivedInputFrameId = MAGIC_LAST_SENT_INPUT_FRAME_ID_NORMAL_ADDED
 	pPlayerFromDbInit.BattleState = PlayerBattleStateIns.ADDED_PENDING_BATTLE_COLLIDER_ACK
 
 	pPlayerFromDbInit.ColliderRadius = DEFAULT_PLAYER_RADIUS // Hardcoded
@@ -740,6 +742,7 @@ func (pR *Room) OnDismissed() {
 	pR.RenderFrameBuffer = battle.NewRingBuffer(pR.RenderCacheSize)
 	pR.InputsBuffer = battle.NewRingBuffer((pR.RenderCacheSize >> 1) + 1)
 	pR.rdfIdToActuallyUsedInput = make(map[int32]*pb.InputFrameDownsync)
+	pR.LastIndividuallyConfirmedInputList = make([]uint64, pR.Capacity)
 
 	pR.LatestPlayerUpsyncedInputFrameId = -1
 	pR.LastAllConfirmedInputFrameId = -1
@@ -1033,18 +1036,10 @@ func (pR *Room) getOrPrefabInputFrameDownsync(inputFrameId int32) *battle.InputF
 				ConfirmedList: uint64(0),
 			}
 
-			j2 := j - 1
-			tmp2 := pR.InputsBuffer.GetByFrameId(j2)
-			if nil != tmp2 {
-				prevInputFrameDownsync := tmp2.(*battle.InputFrameDownsync)
-				for i, _ := range currInputFrameDownsync.InputList {
-					currInputFrameDownsync.InputList[i] = prevInputFrameDownsync.InputList[i]
-				}
-			}
-
 			for i, _ := range currInputFrameDownsync.InputList {
+				// [WARNING] The use of "InputsBufferLock" guarantees that by now "inputFrameId >= pR.InputsBuffer.EdFrameId >= pR.LatestPlayerUpsyncedInputFrameId", thus it's safe to use "pR.LastIndividuallyConfirmedInputList" for prediction.
 				// Don't predict "btnA & btnB"!
-				currInputFrameDownsync.InputList[i] = (currInputFrameDownsync.InputList[i] & uint64(15))
+				currInputFrameDownsync.InputList[i] = (pR.LastIndividuallyConfirmedInputList[i] & uint64(15))
 			}
 
 			pR.InputsBuffer.Put(currInputFrameDownsync)
@@ -1066,8 +1061,8 @@ func (pR *Room) markConfirmationIfApplicable(inputFrameUpsyncBatch []*pb.InputFr
 			Logger.Debug(fmt.Sprintf("Omitting obsolete inputFrameUpsync#1: roomId=%v, playerId=%v, clientInputFrameId=%v, InputsBuffer=%v", pR.Id, playerId, clientInputFrameId, pR.InputsBufferString(false)))
 			continue
 		}
-		if clientInputFrameId < pR.LastAllConfirmedInputFrameId {
-			Logger.Debug(fmt.Sprintf("Omitting obsolete inputFrameUpsync#2: roomId=%v, playerId=%v, clientInputFrameId=%v, InputsBuffer=%v", pR.Id, playerId, clientInputFrameId, pR.InputsBufferString(false)))
+		if clientInputFrameId < player.LastReceivedInputFrameId {
+			Logger.Debug(fmt.Sprintf("Omitting obsolete inputFrameUpsync#2: roomId=%v, playerId=%v, clientInputFrameId=%v, playerLastReceivedInputFrameId=%v, InputsBuffer=%v", pR.Id, playerId, clientInputFrameId, player.LastReceivedInputFrameId, pR.InputsBufferString(false)))
 			continue
 		}
 		if clientInputFrameId > pR.InputsBuffer.EdFrameId {
@@ -1079,6 +1074,9 @@ func (pR *Room) markConfirmationIfApplicable(inputFrameUpsyncBatch []*pb.InputFr
 		targetInputFrameDownsync.InputList[player.JoinIndex-1] = inputFrameUpsync.Encoded
 		targetInputFrameDownsync.ConfirmedList |= uint64(1 << uint32(player.JoinIndex-1))
 
+		player.LastReceivedInputFrameId = clientInputFrameId
+		pR.LastIndividuallyConfirmedInputList[player.JoinIndex-1] = inputFrameUpsync.Encoded
+
 		if clientInputFrameId > pR.LatestPlayerUpsyncedInputFrameId {
 			pR.LatestPlayerUpsyncedInputFrameId = clientInputFrameId
 		}

frontend/assets/scenes/login.fire

@@ -440,7 +440,7 @@
       "array": [
         0,
         0,
-        216.50635094610968,
+        210.60543794365393,
         0,
         0,
         0,

frontend/assets/scripts/Map.js

@@ -1082,14 +1082,6 @@ othersForcedDownsyncRenderFrame=${JSON.stringify(othersForcedDownsyncRenderFrame
       }
       const nextRdf = gopkgs.ApplyInputFrameDownsyncDynamicsOnSingleRenderFrameJs(self.recentInputCache, currRdf, collisionSys, collisionSysMap, self.spaceOffsetX, self.spaceOffsetY, self.chConfigsOrderedByJoinIndex);
 
-      if (3 == nextRdf.PlayersArr[0].ActiveSkillId && 3 != currRdf.PlayersArr[0].ActiveSkillId) {
-        console.log(`Started skill 3 at rdf.Id=${nextRdf.Id}`);
-        self.lastSkill3Started = nextRdf.Id;
-      }
-      if (3 != nextRdf.PlayersArr[0].ActiveSkillId && 3 == currRdf.PlayersArr[0].ActiveSkillId) {
-        console.log(`Stopped skill 3 at rdf.Id=${nextRdf.Id}, duration = ${nextRdf.Id-self.lastSkill3Started}`);
-      }
-
       if (true == isChasing) {
         // [WARNING] Move the cursor "self.chaserRenderFrameId" when "true == isChasing", keep in mind that "self.chaserRenderFrameId" is not monotonic!
         self.chaserRenderFrameId = nextRdf.Id;