// To build: link with OpenGL32.lib;qtmaind.lib;Qt5Widgetsd.lib;Qt5OpenGLd.lib;Qt5Cored.lib;Qt5Guid.lib

#include <QtWidgets/QApplication>
#include <QtWidgets/QMainWindow>
#include <QtWidgets/QVBoxLayout>
#include <QtGui/QMouseEvent>
#include <QtOpenGL/QGLWidget>
#include <iostream>

// QMouseEvent position is correct with this widget
class TestWidget : public QGLWidget
{
public:
	TestWidget(QWidget* parent) {}

	void mousePressEvent(QMouseEvent* e)
	{
		std::cout << "TestGLWidget::mousePressEvent():" << std::endl;
		std::cout << "e->pos():      " << e->pos().x() << ", " << e->pos().y() << std::endl;
		std::cout << "e->localPos(): " << e->localPos().x() << ", " << e->localPos().y() << std::endl;
	}
};

// QMouseEvent position is *incorrect* with this widget, when the window is created on the second monitor.
class TestGLWidget : public QGLWidget
{
public:
	TestGLWidget(QWidget* parent) : QGLWidget(parent) {}

	void mousePressEvent(QMouseEvent* e)
	{
		std::cout << "TestGLWidget::mousePressEvent():" << std::endl;
		std::cout << "e->pos():      " << e->pos().x() << ", " << e->pos().y() << std::endl;
		std::cout << "e->localPos(): " << e->localPos().x() << ", " << e->localPos().y() << std::endl;
	}

	void paintGL()
	{
		glClearColor(0, 0, 1, 0); // Clear with a blue colour.
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

		// Draw a red quad that should cover the entire viewport
		glColor3f(1, 0, 0);
		glBegin(GL_QUADS);
		glVertex2d(-1, -1);
		glVertex2d(1, -1);
		glVertex2d(1, 1);
		glVertex2d(-1, 1);
		glEnd();
	}

	void resizeGL(int xres, int yres)
	{
		std::cout << "resizeGL(): xres: " << xres << ", yres: " << yres << std::endl;

		glViewport(0, 0, xres, yres); // NOTE: This results in a misplaced quad
	}

};

int main(int argc, char *argv[])
{
	QApplication app(argc, argv);

	QMainWindow main_window;
	main_window.setGeometry(/*x=*/3500, /*y=*/500, 500, 300); // NOTE: to replicate issue, choose x and y such that the window is positioned on second monitor.

	// Make central widget for main window
	QWidget* central_widget = new QWidget(&main_window);
	central_widget->setLayout(new QVBoxLayout(central_widget));
	central_widget->layout()->setContentsMargins(0, 0, 0, 0);
	main_window.setCentralWidget(central_widget);

	// TestWidget* test_widget = new TestWidget(central_widget);
	// central_widget->layout()->addWidget(test_widget);
	
	TestGLWidget* test_glwidget = new TestGLWidget(central_widget);
	central_widget->layout()->addWidget(test_glwidget);

	main_window.show();
	return app.exec();
}