add new struct and events

example/layers/meson.build

@@ -0,0 +1,22 @@
+inc += include_directories('.')
+
+headers = [ 
+  'ui_layer/ui_layer.hpp',
+]
+
+sources = [ 
+  'ui_layer/ui_layer.cpp',
+]
+
+lib = library(
+  'vertex_engine_sandbox',
+  include_directories : inc,
+  sources: [headers, sources],
+  dependencies : deps,
+  cpp_args: args
+)
+
+deps += declare_dependency(
+  include_directories: inc, 
+  link_with: lib, 
+)