openglwindow.cpp

//-----------------------------------------------------------------------------
// This file is part of AEO-Light
//
// Copyright (c) 2016 University of South Carolina
//
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2 of the License, or (at your
// option) any later version.
//
// AEO-Light is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, write to the Free Software Foundation, Inc.,
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
// Funding for AEO-Light development was provided through a grant from the
// National Endowment for the Humanities
//-----------------------------------------------------------------------------

#include "openglwindow.h"
#include <iostream>
#include <QtCore/QCoreApplication>
#include <QDebug>

#include <QtGui/QOpenGLContext>
#include <QtGui/QOpenGLPaintDevice>
#include <QtGui/QPainter>

OpenGLWindow::OpenGLWindow(QWindow *parent)
	: QWindow(parent)
	, m_update_pending(false)
	, m_animating(false)
	, m_context(0)
	, m_device(0)
{
	/*
	this->format().setProfile(QSurfaceFormat::CoreProfile);
	this->format().setVersion(4,1);
	*/
	this->setSurfaceType(QWindow::OpenGLSurface);
}

OpenGLWindow::~OpenGLWindow()
{
	delete m_device;
}
void OpenGLWindow::render(QPainter *painter)
{
	Q_UNUSED(painter);
}

void OpenGLWindow::initialize()
{
}

void OpenGLWindow::render()
{
	if (!m_device)
		m_device = new QOpenGLPaintDevice;

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

	m_device->setSize(size());

	QPainter painter(m_device);
	render(&painter);
}

void OpenGLWindow::renderLater()
{
	if (!m_update_pending) {
		m_update_pending = true;
		QCoreApplication::postEvent(this, new QEvent(QEvent::UpdateRequest));
	}
}

bool OpenGLWindow::event(QEvent *event)
{
	switch (event->type())
	{
	case QEvent::UpdateRequest:
		m_update_pending = false;
        renderNow();
		return true;
	default:
		return QWindow::event(event);
	}
}

void OpenGLWindow::exposeEvent(QExposeEvent *event)
{
	Q_UNUSED(event);

    if (isExposed())
        renderNow();
}

void OpenGLWindow::renderNow()
{
	if (!isExposed())
		return;

	bool needsInitialize = false;

	if (!m_context) {
		m_context = new QOpenGLContext(this);
		m_context->setFormat(requestedFormat());
		m_context->create();

		needsInitialize = true;
	}

	m_context->makeCurrent(this);

	if (needsInitialize) {
		initializeOpenGLFunctions();
		initialize();
	}

	render();

	m_context->swapBuffers(this);

	if (m_animating)
		renderLater();
}

void OpenGLWindow::setAnimating(bool animating)
{
	m_animating = animating;

	if (animating)
		renderLater();
}

QString OpenGLWindow::GLVersionString()
{
	if(this->m_context)
		return QString("%1.%2").
				arg(this->m_context->format().majorVersion()).
				arg(this->m_context->format().minorVersion());
	else
		return "?";
}

void OpenGLWindow::PrintGLVersion(QTextStream &stream)
{
	stream << "OpenGL version "
		<< (this->m_context->format().majorVersion()) << "."
		<< (this->m_context->format().minorVersion()) << "\n";
}