Implement Emscripten Websockets

CMakeLists.txt

@@ -146,6 +146,7 @@ if (CMAKE_SYSTEM_NAME STREQUAL Emscripten)
     )
 
     target_link_options(${MAIN_NAME} PRIVATE 
+        "-lwebsocket.js"
         "-sUSE_SDL=2"
         "-sASYNCIFY"
         "-sUSE_WEBGL2=1"

src/client/main.cpp

@@ -6,6 +6,8 @@
 #ifdef EMSCRIPTEN
 #include <emscripten.h>
 #include <emscripten/html5_webgl.h>
+#include <emscripten/emscripten.h>
+#include <emscripten/websocket.h>
 #else
 #include <easywsclient.hpp>
 #endif // EMSCRIPTEN
@@ -151,12 +153,153 @@ static void PollEvents()
     }
 }
 
+#define WS_URL "ws://deadfish.cz:11200/ws"
+
+static bool s_ws_connected = false;
+
+#ifdef EMSCRIPTEN
+
+static EMSCRIPTEN_WEBSOCKET_T s_ws = 0;
+
+static EM_BOOL OnWSOpen(int type, const EmscriptenWebSocketOpenEvent *ev, void *ud)
+{
+    s_ws_connected = true;
+    s_app->Connected();
+    return EM_TRUE;
+}
+
+static EM_BOOL OnWSMessage(int type, const EmscriptenWebSocketMessageEvent *ev, void *ud)
+{
+    if (ev->isText)
+        return EM_TRUE;
+
+    net::InMessage msg(reinterpret_cast<char*>(ev->data), ev->numBytes);
+    s_app->ProcessMessage(msg);
+
+    return EM_TRUE;
+}
+
+static EM_BOOL OnWSClose(int type, const EmscriptenWebSocketCloseEvent *ev, void *ud)
+{
+    s_ws_connected = false;
+    s_app->Disconnected("");
+    return EM_TRUE;
+}
+
+static EM_BOOL OnWSError(int type, const EmscriptenWebSocketErrorEvent *ev, void *ud)
+{
+    s_ws_connected = false;
+    s_app->Disconnected("error");
+    return EM_TRUE;
+}
+
+static bool WSInit()
+{
+    if (!emscripten_websocket_is_supported())
+    {
+        std::cerr << "EMSCRIPTEN WS NOT SUPPORTED" << std::endl;
+        return false;
+    }
+    EmscriptenWebSocketCreateAttributes ws_attrs = {
+        WS_URL,
+        NULL,
+        EM_TRUE
+    };
+
+    s_ws = emscripten_websocket_new(&ws_attrs);
+    emscripten_websocket_set_onopen_callback(s_ws, NULL, OnWSOpen);
+    emscripten_websocket_set_onmessage_callback(s_ws, NULL, OnWSMessage);
+    emscripten_websocket_set_onclose_callback(s_ws, NULL, OnWSClose);
+    emscripten_websocket_set_onerror_callback(s_ws, NULL, OnWSError);
+
+    return true;
+}
+
+static void WSSend(std::span<const char> data)
+{
+    emscripten_websocket_send_binary(s_ws, (void*)data.data(), static_cast<uint32_t>(data.size()));
+}
+
+static void WSPoll() {}
+static void WSClose() {}
+
+#else /* !EMSCRIPTEN */
+
+using namespace easywsclient; 
+
+static std::unique_ptr<WebSocket> s_ws;
+
+static bool WSInit()
+{
+
+#ifdef _WIN32
+    INT rc;
+    WSADATA wsaData;
+
+    rc = WSAStartup(MAKEWORD(2, 2), &wsaData);
+    if (rc)
+    {
+        printf("WSAStartup Failed.\n");
+        return false;
+    }
+#endif
+
+    s_ws = std::unique_ptr<WebSocket>(WebSocket::from_url(WS_URL));
+
+    if (!s_ws)
+        return false;
+
+    return true;
+}
+
+static void WSSend(std::span<const char> data)
+{
+    static std::vector<uint8_t> data;
+    data.resize(msg.size_bytes());
+    memcpy(data.data(), msg.data(), msg.size_bytes());
+    ws->sendBinary(data);
+}
+
+static void WSPoll()
+{
+    s_ws->poll();
+
+    auto ws_state = s_ws->getReadyState();
+    if (ws_state == WebSocket::OPEN && !connected)
+    {
+        connected = true;
+        s_app->Connected();
+    }
+    else if (ws_state != WebSocket::OPEN && connected)
+    {
+        connected = false;
+        s_app->Disconnected("WS closed");
+    }
+
+    s_ws->dispatchBinary([&](const std::vector<uint8_t>& data) {
+        net::InMessage msg(reinterpret_cast<const char*>(data.data()), data.size());
+        s_app->ProcessMessage(msg);
+    });
+}
+
+static void WSClose()
+{
+    s_ws.reset();
+
+#ifdef _WIN32
+    WSACleanup();
+#endif
+}
+
+#endif /* EMSCRIPTEN */
+
 static void Frame()
 {
     Uint32 current_time = SDL_GetTicks();
     s_app->SetTime(current_time / 1000.0f); // Set time in seconds
 
     PollEvents();
+    WSPoll();
 
 	int width, height;
 	SDL_GetWindowSize(s_window, &width, &height);
@@ -204,10 +347,25 @@ static void Frame()
 	s_app->SetInput(input);
 
     s_app->Frame();
+
+    if (s_ws_connected)
+    {
+        auto msg = s_app->GetMsg();
+        if (!msg.empty())
+        {
+            WSSend(msg);
+        }
+    }
+
+    s_app->ResetMsg();
+
     SDL_GL_SwapWindow(s_window);
 }
 
 static void Main() {
+    if (!WSInit())
+        return;
+
     InitSDL();
 
     try
@@ -228,76 +386,18 @@ static void Main() {
     emscripten_set_main_loop(Frame, 0, true);
 #else
 
-#ifdef _WIN32
-    INT rc;
-    WSADATA wsaData;
-
-    rc = WSAStartup(MAKEWORD(2, 2), &wsaData);
-    if (rc)
-    {
-        printf("WSAStartup Failed.\n");
-        return;
-    }
-#endif
-
     SDL_GL_SetSwapInterval(0);
 
+    while (!s_quit)
     {
-        using namespace easywsclient;
+        Frame();
-
-        auto ws = std::unique_ptr<WebSocket>(WebSocket::from_url("ws://127.0.0.1:11200/ws"));
-        bool connected = false;
-
-        
-        std::vector<uint8_t> data;
-
-        while (ws && !s_quit)
-        {
-            ws->poll();
-
-            auto ws_state = ws->getReadyState();
-            if (ws_state == WebSocket::OPEN && !connected)
-            {
-                connected = true;
-                s_app->Connected();
-            }
-            else if (ws_state != WebSocket::OPEN && connected)
-            {
-                connected = false;
-                s_app->Disconnected("WS closed");
-            }
-
-            ws->dispatchBinary([&](const std::vector<uint8_t>& data) {
-                net::InMessage msg(reinterpret_cast<const char*>(data.data()), data.size());
-                s_app->ProcessMessage(msg);
-            });
-
-            Frame();
-
-            if (connected)
-            {
-                auto msg = s_app->GetMsg();
-                if (!msg.empty())
-                {
-                    data.resize(msg.size_bytes());
-                    memcpy(data.data(), msg.data(), msg.size_bytes());
-                    ws->sendBinary(data);
-                }
-            }
-
-            s_app->ResetMsg();
-        }
-        
     }
-
+        
     s_app.reset();
 
     ShutdownGL();
     ShutdownSDL();
-
+    WSClose();
-#ifdef _WIN32
-    WSACleanup();
-#endif
 
 #endif // EMSCRIPTEN
 }