implement multithreading for windows, implement file uploading when saving

engine/main.cpp

@@ -19,10 +19,74 @@ HDC       hDC;
 HGLRC     hRC;
 wchar_t*  className;
 bool      keys[256];
+std::mutex gl_mutex;
+std::mutex async_mutex;
+std::thread::id gl_thread;
+int gl_count = 0;
 
 #include <WbemCli.h>
 #include "wacom.h"
 
+//Returns the last Win32 error, in string format. Returns an empty string if there is no error.
+std::string GetLastErrorAsString()
+{
+    //Get the error message, if any.
+    DWORD errorMessageID = ::GetLastError();
+    if (errorMessageID == 0)
+        return std::string(); //No error message has been recorded
+
+    LPSTR messageBuffer = nullptr;
+    size_t size = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
+        NULL, errorMessageID, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPSTR)&messageBuffer, 0, NULL);
+
+    std::string message(messageBuffer, size);
+
+    //Free the buffer.
+    LocalFree(messageBuffer);
+
+    return message;
+}
+
+void async_lock()
+{
+    //std::lock_guard<std::mutex> _lock(async_mutex);
+    if (gl_count == 0 || gl_thread != std::this_thread::get_id())
+    {
+        gl_mutex.lock();
+        bool ret = wglMakeCurrent(hDC, hRC);
+        if (ret == false)
+            LOG("FAILED wglMakeCurrent: %s", GetLastErrorAsString().c_str());
+        gl_thread = std::this_thread::get_id();
+        //LOG("lock");
+    }
+    gl_count++;
+    //assert(ret == true);
+}
+
+void async_swap()
+{
+    SwapBuffers(hDC);
+    //LOG("swap");
+}
+
+void async_unlock()
+{
+    //std::lock_guard<std::mutex> _lock(async_mutex);
+    gl_count--;
+    if (gl_count == 0)
+    {
+        //LOG("unlock");
+        wglMakeCurrent(0, 0);
+        gl_mutex.unlock();
+    }
+}
+
+struct async_locker
+{
+    async_locker() { async_lock(); }
+    ~async_locker() { async_unlock(); }
+};
+
 int read_WMI_info()
 {
     // see: http://win32easy.blogspot.co.uk/2011/03/wmi-in-c-query-everyting-from-your-os.html
@@ -303,9 +367,14 @@ int main(int argc, char** argv)
                 t0 = t1;
                 if (App::I.redraw)
                 {
+                    async_lock();
+                    App::I.redraw = true;
+                    glBindFramebuffer(GL_FRAMEBUFFER, 0);
                     App::I.clear();
                     App::I.update((float)(t1 - t0) / 1000.0f);
                     SwapBuffers(hDC);
+                    async_unlock();
+                    //LOG("swap main");
                 }
             }
 //             else
@@ -323,6 +392,7 @@ int main(int argc, char** argv)
 
 LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wp, LPARAM lp)
 {
+    async_locker lock;
     static bool leftDown = false;
     static DWORD lastTime;
     static POINT lastPoint;
@@ -368,7 +438,7 @@ LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wp, LPARAM lp)
         App::I.key_up(convert_key((int)wp));
         break;
     case WM_CHAR:
-        //App::I.key_char((int)wp);
+        App::I.key_char((int)wp);
         break;
     case WM_MOUSEMOVE:
         //TODO: find a way to check if event is mouse/stylus. For now use Mouse for all