Create window on startup and run event loop.

src/main.d

@@ -1,5 +1,15 @@
 static import jtk;
 import std.stdio;
+import derelict.opengl;
+
+jtk.Window window;
+
+static void redraw()
+{
+    glClearColor(0.5, 0.0, 1.0, 0.0);
+    glClear(GL_COLOR_BUFFER_BIT);
+    window.swap_buffers();
+}
 
 int main(string[] args)
 {
@@ -10,6 +20,27 @@ int main(string[] args)
     }
     try
     {
+        window = new jtk.Window();
+        bool running = true;
+        while (running)
+        {
+            jtk.Event event = jtk.wait_event();
+            switch (event.type)
+            {
+            case jtk.Event.WINDOW_CLOSE:
+                running = false;
+                break;
+
+            case jtk.Event.WINDOW_RESIZE:
+                glViewport(0, 0, event.window_resize.width, event.window_resize.height);
+                redraw();
+                break;
+
+            default:
+                break;
+            }
+        }
+        window.close();
     }
     finally
     {