shadows basically works

src/core/view/openglwindow.h

@@ -0,0 +1,46 @@
+#include "qglengine_core_export.h"
+
+#include <QOpenGLExtraFunctions>
+#include <QWindow>
+
+class QPainter;
+class QOpenGLContext;
+class QOpenGLPaintDevice;
+
+
+class QGLENGINE_CORE_EXPORT OpenGLWindow
+	: public QWindow
+	, public QOpenGLExtraFunctions {
+	Q_OBJECT
+
+public:
+	explicit OpenGLWindow(QWindow * parent = nullptr);
+	virtual ~OpenGLWindow() {}
+
+	virtual void render() {}
+	virtual void initialize() {}
+
+	QOpenGLContext * context() { return m_context; }
+	void setVSync(bool on);
+	bool getVSync() const;
+	//	void setSamples(int samples);
+	//	int getSamples() const;
+	int getFrameCounter() const { return frame_cnt; }
+
+	int pixelWidth() const;
+	int pixelHeight() const;
+	QSize pixelSize() const;
+
+public slots:
+	void renderLater();
+	void renderNow();
+
+protected:
+	bool event(QEvent * event) override;
+	void exposeEvent(QExposeEvent * event) override;
+
+private:
+	QOpenGLContext * m_context = nullptr;
+	bool format_change         = false;
+	int frame_cnt              = 0;
+};