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3 Commits

Author SHA1 Message Date
Wing
7e89d703ba
Fixed typo. 2023-11-28 08:37:11 +08:00
yflu
dc1e6d3e09 Updated frontend "onPeerInputFrameUpsync" handling for force confirmation. 2023-04-18 07:03:22 +08:00
genxium
28e5c18f00 Fixed typo. 2023-04-14 07:28:01 +08:00
3 changed files with 17 additions and 7 deletions

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@ -1,6 +1,8 @@
Please refer to [DelayNoMoreUnity](https://github.com/genxium/DelayNoMoreUnity) for a Unity rebuild with .net backend.
# Preface
This project is a demo for a websocket-based rollback netcode inspired by [GGPO](https://github.com/pond3r/ggpo/blob/master/doc/README.md).
This project is a demo for a websocket-based rollback netcode inspired by [GGPO](https://github.com/pond3r/ggpo/blob/master/doc/README.md).
[Demo recorded over INTERNET (Phone-Wifi v.s. PC-Wifi UDP holepunched) using an input delay of 6 frames](https://pan.baidu.com/s/1UArwqDShLoPjYppjjqsTqQ?pwd=10wc), and it feels SMOOTH when playing!
@ -23,7 +25,7 @@ As lots of feedbacks ask for a discussion on using UDP instead, I tried to summa
# Notable Features
- Backend dynamics toggle via [Room.BackendDynamicsEnabled](https://github.com/genxium/DelayNoMore/blob/c582071f4f2e3dd7e83d65562c7c99981252c358/battle_srv/models/room.go#L147)
- Recovery upon reconnection (only if backend dynamics is ON)
- Automatically correction for "slow ticker", especially "active slow ticker" which is well-known to be a headache for input synchronization
- Automatic correction for "slow ticker", especially "active slow ticker" which is well-known to be a headache for input synchronization
- Frame data logging toggle for both frontend & backend, useful for debugging out of sync entities when developing new features
_(how input delay roughly works)_

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@ -1003,7 +1003,7 @@ fromUDP=${fromUDP}`);
const inputFrameId = inputFrame.inputFrameId;
const peerEncodedInput = (true == fromUDP ? inputFrame.encoded : inputFrame.inputList[peerJoinIndex - 1]);
if (false == self.allowRollbackOnPeerUpsync && inputFrameId <= renderedInputFrameIdUpper) {
// [WARNING] Avoid obfuscating already rendered history, even at "inputFrameId == renderedInputFrameIdUpper", due to the use of "INPUT_SCALE_FRAMES" some previous render frames might already be rendered with "inputFrameId"!
// [WARNING] Avoid obfuscating already rendered history, even at "inputFrameId == renderedInputFrameIdUpper", due to the use of "INPUT_SCALE_FRAMES" some previous render frames might've already been rendered with "inputFrameId"!
continue;
}
if (inputFrameId <= self.lastAllConfirmedInputFrameId) {
@ -1022,12 +1022,11 @@ fromUDP=${fromUDP}`);
self.lastIndividuallyConfirmedInputList[peerJoinIndex - 1] = peerEncodedInput;
}
effCnt += 1;
// the returned "gopkgs.NewInputFrameDownsync.InputList" is immutable, thus we can only modify the values in "newInputList" and "newConfirmedList"!
// the returned "gopkgs.NewInputFrameDownsync.InputList" is immutable, thus we can only modify the value in "newInputList"!
const existingInputList = existingInputFrame.GetInputList();
let newInputList = existingInputFrame.GetInputList().slice();
newInputList[peerJoinIndex - 1] = peerEncodedInput;
let newConfirmedList = (existingConfirmedList | peerJoinIndexMask);
const newInputFrameDownsyncLocal = gopkgs.NewInputFrameDownsync(inputFrameId, newInputList, newConfirmedList);
const newInputFrameDownsyncLocal = gopkgs.NewInputFrameDownsync(inputFrameId, newInputList, existingConfirmedList);
//console.log(`Updated encoded input of peerJoinIndex=${peerJoinIndex} to ${peerEncodedInput} for inputFrameId=${inputFrameId}/renderedInputFrameIdUpper=${renderedInputFrameIdUpper} from ${JSON.stringify(inputFrame)}; newInputFrameDownsyncLocal=${self.gopkgsInputFrameDownsyncStr(newInputFrameDownsyncLocal)}; existingInputFrame=${self.gopkgsInputFrameDownsyncStr(existingInputFrame)}`);
self.recentInputCache.SetByFrameId(newInputFrameDownsyncLocal, inputFrameId);
@ -1048,6 +1047,15 @@ fromUDP=${fromUDP}`);
self.networkDoctor.logPeerInputFrameUpsync(batch[0].inputFrameId, batch[batch.length - 1].inputFrameId);
}
if (true == self.allowRollbackOnPeerUpsync) {
/*
[WARNING]
Deliberately NOT setting "existingInputFrame.ConfirmedList = (existingConfirmedList | peerJoinIndexMask)", thus NOT helping the move of "lastAllConfirmedInputFrameId" in "_markConfirmationIfApplicable()".
The edge case of concern here is "type#1 forceConfirmation". Assume that there is a battle among [P_u, P_v, P_x, P_y] where [P_x] is being an "ActiveSlowerTicker", then for [P_u, P_v, P_y] there might've been some "inputFrameUpsync"s received from [P_x] by UDP peer-to-peer transmission EARLIER THAN BUT CONFLICTING WITH the "accompaniedInputFrameDownsyncBatch of type#1 forceConfirmation" -- in such case the latter should be respected -- by "conflicting", the backend actually ignores those "inputFrameUpsync"s from [P_x] by "forceConfirmation".
However, we should still call "_handleIncorrectlyRenderedPrediction(...)" here to break rollbacks into smaller chunks, because even if not used for "inputFrameDownsync.ConfirmedList", a "UDP inputFrameUpsync" is still more accurate than the locally predicted inputs.
*/
self._handleIncorrectlyRenderedPrediction(firstPredictedYetIncorrectInputFrameId, batch, fromUDP);
}
},

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@ -100,7 +100,7 @@ bool RecvRingBuff::pop(RecvWork* out) {
2. If "0 >= oldCnt", we need guard against another "pop" to avoid over-popping.
*/
if (0 >= oldCnt) {
// "pop" could be accessed by either "GameThread/pollUdpRecvRingBuff" or "UvRecvThread/put", thus we should be proactively guard against concurrent popping while "1 == cnt"
// "pop" could be accessed by either "GameThread/pollUdpRecvRingBuff" or "UvRecvThread/put", thus we should be proactively guarding against concurrent popping while "1 == cnt"
++cnt;
return false;
}