client egl context and viewport in kotlin UI

src/main/cpp/egl_context.h

@@ -2,7 +2,9 @@
 
 typedef void* EGLContext;
 typedef void*  EGLDisplay;
+typedef void*  EGLSurface;
 typedef void*  EGLConfig;
+struct ANativeWindow;
 
 namespace egl
 {
@@ -10,10 +12,13 @@ class Context
 {
     EGLContext m_context;
     EGLDisplay m_display;
-    EGLConfig m_config = nullptr;
+    EGLSurface m_surface;
+    EGLConfig m_config;
+    ANativeWindow* m_native_window;
 public:
     Context();
-    bool create();
+    bool create(ANativeWindow* window = nullptr);
     void destroy();
+    void swap();
 };
 }