Netplay: Fix latency increase

dep/ggpo-x/include/ggponet.h

@@ -453,6 +453,7 @@ GGPO_API GGPOErrorCode __cdecl ggpo_set_frame_delay(GGPOSession *,
  * in ggpo_idle.
  */
 GGPO_API GGPOErrorCode __cdecl ggpo_idle(GGPOSession *);
+GGPO_API GGPOErrorCode __cdecl ggpo_network_idle(GGPOSession *);
 
 /*
  * ggpo_add_local_input --

dep/ggpo-x/src/backends/backend.h

@@ -15,6 +15,7 @@ class GGPOSession {
 public:
    virtual ~GGPOSession() { }
    virtual GGPOErrorCode DoPoll() = 0;
+   virtual GGPOErrorCode NetworkIdle() = 0;
    virtual GGPOErrorCode AddPlayer(GGPOPlayer *player, GGPOPlayerHandle *handle) = 0;
    virtual GGPOErrorCode AddLocalInput(GGPOPlayerHandle player, void *values, int size) = 0;
    virtual GGPOErrorCode SyncInput(void *values, int size, int *disconnect_flags) = 0;

dep/ggpo-x/src/backends/p2p.cpp

@@ -140,9 +140,6 @@ Peer2PeerBackend::DoPoll()
 {
    if (!_sync.InRollback())
    {
-     for (UdpProtocol& udp : _endpoints)
-       udp.OnLoopPoll();
-
       PollUdpProtocolEvents();
       CheckDesync();
       if (!_synchronizing) {
@@ -205,6 +202,14 @@ Peer2PeerBackend::DoPoll()
    return GGPO_OK;
 }
 
+GGPOErrorCode Peer2PeerBackend::NetworkIdle()
+{
+   for (UdpProtocol& udp : _endpoints)
+      udp.NetworkIdle();
+
+   return GGPO_OK;
+}
+
 int Peer2PeerBackend::Poll2Players(int current_frame)
 {
    int i;

dep/ggpo-x/src/backends/p2p.h

@@ -23,6 +23,7 @@ public:
 
 public:
    virtual GGPOErrorCode DoPoll() override;
+   virtual GGPOErrorCode NetworkIdle() override;
    virtual GGPOErrorCode AddPlayer(GGPOPlayer *player, GGPOPlayerHandle *handle) override;
    virtual GGPOErrorCode AddLocalInput(GGPOPlayerHandle player, void *values, int size) override;
    virtual GGPOErrorCode SyncInput(void *values, int size, int *disconnect_flags) override;

dep/ggpo-x/src/backends/spectator.cpp

@@ -55,6 +55,12 @@ SpectatorBackend::DoPoll()
    return GGPO_OK;
 }
 
+GGPOErrorCode SpectatorBackend::NetworkIdle()
+{
+  _host.NetworkIdle();
+  return GGPO_OK;
+}
+
 GGPOErrorCode
 SpectatorBackend::SyncInput(void *values,
                             int size,

dep/ggpo-x/src/backends/spectator.h

@@ -24,6 +24,7 @@ public:
 
 public:
    virtual GGPOErrorCode DoPoll();
+   virtual GGPOErrorCode NetworkIdle();
    virtual GGPOErrorCode AddPlayer(GGPOPlayer *player, GGPOPlayerHandle *handle) { return GGPO_ERRORCODE_UNSUPPORTED; }
    virtual GGPOErrorCode AddLocalInput(GGPOPlayerHandle player, void *values, int size) { return GGPO_OK; }
    virtual GGPOErrorCode SyncInput(void *values, int size, int *disconnect_flags);

dep/ggpo-x/src/backends/synctest.cpp

@@ -54,6 +54,12 @@ SyncTestBackend::DoPoll()
    return GGPO_OK;
 }
 
+GGPOErrorCode
+SyncTestBackend::NetworkIdle()
+{
+  return GGPO_OK;
+}
+
 GGPOErrorCode
 SyncTestBackend::AddPlayer(GGPOPlayer *player, GGPOPlayerHandle *handle)
 {

dep/ggpo-x/src/backends/synctest.h

@@ -19,6 +19,7 @@ public:
    virtual ~SyncTestBackend();
 
    virtual GGPOErrorCode DoPoll();
+   virtual GGPOErrorCode NetworkIdle();
    virtual GGPOErrorCode AddPlayer(GGPOPlayer *player, GGPOPlayerHandle *handle);
    virtual GGPOErrorCode AddLocalInput(GGPOPlayerHandle player, void *values, int size);
    virtual GGPOErrorCode SyncInput(void *values, int size, int *disconnect_flags);

dep/ggpo-x/src/main.cpp

@@ -100,6 +100,15 @@ ggpo_idle(GGPOSession *ggpo)
    return ggpo->DoPoll();
 }
 
+GGPOErrorCode
+ggpo_network_idle(GGPOSession* ggpo)
+{
+  if (!ggpo) {
+    return GGPO_ERRORCODE_INVALID_SESSION;
+  }
+  return ggpo->NetworkIdle();
+}
+
 GGPOErrorCode
 ggpo_add_local_input(GGPOSession *ggpo,
                      GGPOPlayerHandle player,

dep/ggpo-x/src/network/udp_proto.cpp

@@ -186,7 +186,7 @@ void UdpProtocol::EndPollLoop()
 }
 
 bool
-UdpProtocol::OnLoopPoll()
+UdpProtocol::NetworkIdle()
 {
    if (!_peer) {
       return true;

dep/ggpo-x/src/network/udp_proto.h

@@ -57,7 +57,7 @@ public:
    };
 
 public:
-   bool OnLoopPoll();
+   bool NetworkIdle();
 
 public:
    UdpProtocol();

src/core/netplay.cpp

@@ -588,6 +588,8 @@ void Netplay::Throttle()
   {
     // TODO: make better, we can tell this function to stall until the next frame
     PollEnet(0);
+    ggpo_network_idle(s_ggpo);
+    PollEnet(0);
 
     current_time = Common::Timer::GetCurrentValue();
     if (current_time >= s_next_frame_time)
@@ -650,7 +652,12 @@ void Netplay::AdvanceFrame()
 void Netplay::RunFrame()
 {
   // housekeeping
+  // TODO: get rid of double polling
+  PollEnet(0);
+  ggpo_network_idle(s_ggpo);
+  PollEnet(0);
   ggpo_idle(s_ggpo);
+
   // run game
   auto result = GGPO_OK;
   int disconnect_flags = 0;