opengl renderer: create rendering subwindow

The application provides the window handle to which the
OpenglRenderer should render to however only a sub-region of
this window needs to be rendered. This change adds this functionality
by creating a native child subwindow into which rendering will happen.

tools/emulator/opengl/host/libs/libOpenglRender/NativeWindowsSubWindow.cpp

@@ -0,0 +1,55 @@
+/*
+* Copyright (C) 2011 The Android Open Source Project
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+#include "NativeSubWindow.h"
+#include <stdio.h>
+
+LRESULT CALLBACK myWndProc(HWND hwnd,UINT uMsg,WPARAM wParam,LPARAM lParam)
+{
+    return DefWindowProc(hwnd, uMsg, wParam, lParam);
+}
+
+EGLNativeWindowType createSubWindow(FBNativeWindowType p_window,
+                                    EGLNativeDisplayType* display_out,
+                                    int x, int y,int width, int height){
+    WNDCLASS wc;
+    wc.style =  CS_OWNDC |CS_HREDRAW |CS_VREDRAW;  // redraw if size changes
+    wc.lpfnWndProc = myWndProc;                 // points to window procedure
+    wc.cbClsExtra = 0;                             // no extra class memory
+    wc.cbWndExtra = sizeof(void*);                 // save extra window memory, to store VasWindow instance
+    wc.hInstance = NULL;                           // handle to instance
+    wc.hIcon = NULL;                               // predefined app. icon
+    wc.hCursor = NULL;
+    wc.hbrBackground = NULL;                       // no background brush
+    wc.lpszMenuName =  NULL;                       // name of menu resource
+    wc.lpszClassName = "subWin";                 // name of window class
+
+    RegisterClass(&wc);
+    printf("creating window %d %d %d %d\n",x,y,width,height);
+    EGLNativeWindowType ret = CreateWindow("subWin",
+                        "sub",
+                        WS_CHILD,
+                        x,y,width,height,
+                        p_window,
+                        NULL,
+                        NULL,
+                        NULL);
+    ShowWindow(ret,SW_SHOW);
+    return ret;
+}
+
+void destroySubWindow(EGLNativeDisplayType dis,EGLNativeWindowType win){
+    DestroyWindow(win);
+}