license message box on Windows

engine/app.cpp

@@ -168,11 +168,21 @@ bool App::check_license()
     CURL *curl = curl_easy_init();
     if (curl)
     {
-        std::string url = "http://omigamedev.com/panopainter/79516B99-8E67-40AD-B12F-149A5A9C2E15";
+        //std::string url = "http://omigamedev.com/panopainter/79516B99-8E67-40AD-B12F-149A5A9C2E15";
+        std::string url = "https://panopainter.com/license/E8EDC2FE-E1BD-4AB1-91BD-FCCD926739BD.php";
+        std::string ret;
         curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
         curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1L);
+
+        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &ret);
+        //curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
+        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, curl_data_handler);
+        curl_easy_setopt(curl, CURLOPT_TIMEOUT, 2L);
+
         auto err = curl_easy_perform(curl);
         curl_easy_cleanup(curl);
+
+        LOG("License check: %s", ret.c_str());
         if (err == CURLcode::CURLE_OK)
             return true;
     }

engine/main.cpp

@@ -293,12 +293,16 @@ int main(int argc, char** argv)
     WNDCLASS wc;
     PIXELFORMATDESCRIPTOR pfd;
 
-    if (!App::I.check_license())
-        return -1;
-
     if (argc == 1)
         App::I.initLog();
 
+    if (!App::I.check_license())
+    {
+        MessageBoxA(NULL, "Unable to verify this demo license, please make sure you are connected to Internet.",
+            "PanoPainter - License Error", MB_ICONERROR | MB_OK);
+        return -1;
+    }
+
     SetupExceptionHandler();
     BT_SetTerminate();
 

engine/shape.h

@@ -30,9 +30,11 @@ public:
     void draw_stroke() const;
     void destroy()
     {
-        glDeleteBuffers(2, buffers);
+        if (buffers[0] || buffers[1])
+            glDeleteBuffers(2, buffers);
 #if USE_VBO
-        glDeleteVertexArrays(2, arrays);
+        if (arrays[0] || arrays[1])
+            glDeleteVertexArrays(2, arrays);
 #endif // USE_VBO
         buffers[0] = buffers[1] = 0;
         arrays[0] = arrays[1] = 0;