base for forwarding input to clients

src/frontend/qt_sdl/Input.h

@@ -19,6 +19,9 @@
 #ifndef INPUT_H
 #define INPUT_H
 
+#include <SDL2/SDL.h>
+#include <QKeyEvent>
+
 #include "types.h"
 
 namespace Input

src/frontend/qt_sdl/Netplay.cpp

@@ -19,10 +19,17 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <queue>
 
 #include <enet/enet.h>
 
+#include "NDS.h"
+#include "main.h"
 #include "Netplay.h"
+#include "Input.h"
+
+
+extern EmuThread* emuThread;
 
 
 namespace Netplay
@@ -34,6 +41,14 @@ bool IsHost;
 ENetHost* Host;
 ENetPeer* Peer;
 
+struct InputFrame
+{
+    u32 FrameNum;
+    u32 KeyMask;
+};
+
+std::queue<InputFrame> InputQueue;
+
 
 bool Init()
 {
@@ -119,26 +134,158 @@ void StartClient()
 }
 
 
+void StartGame()
+{
+    if (!IsHost)
+    {
+        printf("?????\n");
+        return;
+    }
+
+    // tell remote peers to start game
+    u8 cmd[1] = {0x01};
+    ENetPacket* pkt = enet_packet_create(cmd, sizeof(cmd), ENET_PACKET_FLAG_RELIABLE);
+    enet_host_broadcast(Host, 0, pkt);
+
+    // start game locally
+    NDS::Start();
+    emuThread->emuRun();
+}
+
+
 void ProcessFrame()
 {
+    bool block = false;
+    if (emuThread->emuIsRunning())
+    {
+        if (IsHost)
+        {
+            // TODO: prevent the clients from running too far behind
+        }
+        else
+        {
+            // block if we ran out of input frames
+            // TODO: in this situation, make sure we do receive an input frame
+            // or if we don't after X time, handle it gracefully
+
+            if (InputQueue.empty())
+                block = true;
+        }
+    }
+    block=false;
+
     ENetEvent event;
-    while (enet_host_service(Host, &event, 0) > 0)
+    while (enet_host_service(Host, &event, block ? 5000 : 0) > 0)
     {
         switch (event.type)
         {
         case ENET_EVENT_TYPE_CONNECT:
             printf("client connected %08X %d\n", event.peer->address.host, event.peer->address.port);
+            Peer = event.peer;
             break;
 
         case ENET_EVENT_TYPE_DISCONNECT:
             printf("client disconnected %08X %d\n", event.peer->address.host, event.peer->address.port);
+            Peer = nullptr;
             break;
 
         case ENET_EVENT_TYPE_RECEIVE:
-            printf("received shit\n");
+            {
+                if (event.packet->dataLength < 1)
+                {
+                    printf("?????\n");
+                    break;
+                }
+
+                u8* data = (u8*)event.packet->data;
+                switch (data[0])
+                {
+                case 0x01: // start game
+                    NDS::Start();
+                    emuThread->emuRun();
+                    break;
+
+                case 0x02: // input frame
+                    {
+                        if (event.packet->dataLength != (sizeof(InputFrame)+1))
+                            break;
+
+                        InputFrame frame;
+                        memcpy(&frame, &data[1], sizeof(InputFrame));
+                        InputQueue.push(frame);
+                        break;
+                    }
+                }
+            }
             break;
         }
     }
 }
 
+void ProcessInput()
+{
+    // netplay input processing
+    //
+    // N = current frame #
+    // L = amount of lag frames
+    //
+    // host side:
+    // we take the current input (normally meant for frame N)
+    // and delay it to frame N+L
+    //
+    // client side:
+    // we receive input from the host
+    // apply each input to the frame it's assigned to
+    // before running a frame, we need to wait to have received input for it
+    // TODO: alert host if we are running too far behind
+
+    if (IsHost)
+    {
+        u32 lag = 4; // TODO: make configurable!!
+
+        InputFrame frame;
+        frame.FrameNum = NDS::NumFrames + lag;
+        frame.KeyMask = Input::InputMask;
+        // TODO: touchscreen input and other shit!
+
+        InputQueue.push(frame);
+
+        u8 cmd[1+sizeof(InputFrame)];
+        cmd[0] = 0x02;
+        memcpy(&cmd[1], &frame, sizeof(InputFrame));
+        ENetPacket* pkt = enet_packet_create(cmd, sizeof(cmd), ENET_PACKET_FLAG_RELIABLE);
+        enet_host_broadcast(Host, 0, pkt);
+    }
+
+    if (InputQueue.empty())
+    {
+        printf("Netplay: BAD! INPUT QUEUE EMPTY\n");
+        return;
+    }
+
+    InputFrame& frame = InputQueue.front();
+
+    if (frame.FrameNum < NDS::NumFrames)
+    {
+        printf("Netplay: BAD! LAGGING BEHIND\n");
+        while (frame.FrameNum < NDS::NumFrames)
+        {
+            if (InputQueue.size() < 2) break;
+            InputQueue.pop();
+            frame = InputQueue.front();
+        }
+    }
+
+    if (frame.FrameNum > NDS::NumFrames)
+    {
+        // frame in the future, ignore
+        return;
+    }
+
+    // apply this input frame
+    printf("[%08d] INPUT=%08X (%08d) (backlog=%d)\n", NDS::NumFrames, frame.KeyMask, frame.FrameNum, InputQueue.size());
+    NDS::SetKeyMask(frame.KeyMask);
+    InputQueue.pop();
+}
+
 }

src/frontend/qt_sdl/Netplay.h

@@ -32,7 +32,10 @@ void DeInit();
 void StartHost();
 void StartClient();
 
+void StartGame();
+
 void ProcessFrame();
+void ProcessInput();
 
 }
 

src/frontend/qt_sdl/main.cpp

@@ -472,7 +472,14 @@ void EmuThread::run()
             }
 
             // process input and hotkeys
-            NDS::SetKeyMask(Input::InputMask);
+            if (Netplay::Active)
+            {
+                Netplay::ProcessInput();
+            }
+            else
+            {
+                NDS::SetKeyMask(Input::InputMask);
+            }
 
             if (Input::HotkeyPressed(HK_Lid))
             {
@@ -1576,6 +1583,9 @@ MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent)
 
             actMPStartClient = submenu->addAction("NETPLAY CLIENT");
             connect(actMPStartClient, &QAction::triggered, this, &MainWindow::onMPStartClient);
+
+            actMPTest = submenu->addAction("NETPLAY GO");
+            connect(actMPTest, &QAction::triggered, this, &MainWindow::onMPTest);
         }
     }
     {
@@ -2337,8 +2347,11 @@ void MainWindow::onOpenFile()
     recentFileList.prepend(filename);
     updateRecentFilesMenu();
 
-    NDS::Start();
-    emuThread->emuRun();
+    if (!Netplay::Active)
+    {
+        NDS::Start();
+        emuThread->emuRun();
+    }
 
     updateCartInserted(false);
 }
@@ -2434,8 +2447,11 @@ void MainWindow::onClickRecentFile()
     recentFileList.prepend(filename);
     updateRecentFilesMenu();
 
-    NDS::Start();
-    emuThread->emuRun();
+    if (!Netplay::Active)
+    {
+        NDS::Start();
+        emuThread->emuRun();
+    }
 
     updateCartInserted(false);
 }
@@ -2458,8 +2474,11 @@ void MainWindow::onBootFirmware()
         return;
     }
 
-    NDS::Start();
-    emuThread->emuRun();
+    if (!Netplay::Active)
+    {
+        NDS::Start();
+        emuThread->emuRun();
+    }
 }
 
 void MainWindow::onInsertCart()
@@ -2844,6 +2863,12 @@ void MainWindow::onMPStartClient()
     Netplay::StartClient();
 }
 
+void MainWindow::onMPTest()
+{
+    // HAX
+    Netplay::StartGame();
+}
+
 void MainWindow::onOpenEmuSettings()
 {
     emuThread->emuPause();

src/frontend/qt_sdl/main.h

@@ -313,6 +313,7 @@ private slots:
     void onMPNewInstance();
     void onMPStartHost();
     void onMPStartClient();
+    void onMPTest();
 
     void onOpenEmuSettings();
     void onEmuSettingsDialogFinished(int res);
@@ -412,6 +413,7 @@ public:
     QAction* actMPNewInstance;
     QAction* actMPStartHost;
     QAction* actMPStartClient;
+    QAction* actMPTest;
 
     QAction* actEmuSettings;
 #ifdef __APPLE__