refactor Windows classes to separate EGL/WGL/Backing Window

windows/CMakeLists.txt

@@ -22,16 +22,22 @@ list(APPEND PLUGIN_SOURCES
   "${CMAKE_CURRENT_SOURCE_DIR}/../ios/src/camutils/Bookmark.cpp"
 )
 
-set(USE_ANGLE TRUE)
+set(USE_ANGLE FALSE)
+
+if(!USE_ANGLE)
+set(WGL_USE_BACKING_WINDOW TRUE)
+endif()
 
 if(USE_ANGLE)
   add_compile_definitions(USE_ANGLE)
-  list(APPEND PLUGIN_SOURCES 
-  # "PlatformAngle.cpp" 
-  "flutter_angle_texture.cpp"
-  )
+  list(APPEND PLUGIN_SOURCES    "flutter_angle_texture.cpp"   "egl_context.cpp"   )
 else() 
-  list(APPEND PLUGIN_SOURCES "opengl_texture_buffer.cpp")
+  list(APPEND PLUGIN_SOURCES "wgl_context.cpp")
+  if(WGL_USE_BACKING_WINDOW)
+    list(APPEND PLUGIN_SOURCES "utils.cc" "backing_window.cpp")
+  else()
+    list(APPEND PLUGIN_SOURCES "opengl_texture_buffer.cpp")
+  endif()
 endif()
 
 # Define the plugin library target. Its name must not be changed (see comment
@@ -74,9 +80,9 @@ if(USE_ANGLE)
 else()
   list(APPEND GL_LIBS
     bluegl
-    # bluevk
-    # vkshaders
     opengl32
+    dwmapi
+    comctl32
   )
   set(ANGLE_OR_OPENGL_DIR opengl)
   add_library(bluegl SHARED IMPORTED)