began large scale restructure

app/widget/viewer/viewerglwidget.cpp

@@ -0,0 +1,17 @@
+#include "viewerglwidget.h"
+
+#include <QOpenGLContext>
+#include <QOpenGLFunctions>
+
+ViewerGLWidget::ViewerGLWidget()
+{
+
+}
+
+void ViewerGLWidget::paintGL()
+{
+  QOpenGLFunctions* f = context()->functions();
+
+  f->glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
+  f->glClear(GL_COLOR_BUFFER_BIT);
+}