/******************************************************************************
 *   Copyright (C) 2008 by Oliver Bock                                        *
 *   oliver.bock[AT]aei.mpg.de                                                *
 *                                                                            *
 *   This file is part of PulsatingScience.                                   *
 *                                                                            *
 *   PulsatingScience 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, version 3 of the License.               *
 *                                                                            *
 *   PulsatingScience 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 PulsatingScience. If not, see <http://www.gnu.org/licenses/>. *
 *                                                                            *
 ******************************************************************************/

#include "pulsaranimationwidget.h"

const float PulsarAnimationWidget::deg2rad = PI/180.0f;

PulsarAnimationWidget::PulsarAnimationWidget(QWidget *parent) :
	QGLWidget(QGLFormat(QGL::AlphaChannel | QGL::SampleBuffers), parent),
	m_frameTimer()
{
	if(!format().rgba()) {
		qWarning("Sorry, no RGBA support...");
	}
	if(!format().alpha()) {
		qWarning("Sorry, no alpha channel support...");
	}
	if(!format().sampleBuffers()) {
		qWarning("Sorry, no multisampling support...");
	}

    connect(&m_frameTimer, SIGNAL(timeout()), this, SLOT(updateFrame()));

    m_quadricPulsarOrbitPlane = NULL;
	m_quadricPulsar = NULL;
	m_quadricPulsarCone1 = NULL;
	m_quadricPulsarCone2 = NULL;

	m_framesPerSecond = 25;

	resetParameters();

	m_cameraInteraction = false;
	m_mouseLastX = 0;
	m_mouseLastY = 0;
	m_mouseAngleH = 90.0f;
	m_mouseAngleV = 30.f;
	m_cameraZoom = 15.0f;
	m_cameraZoomLBound = 2.0f;

	updateCameraPosition(m_mouseAngleH, m_mouseAngleV, m_cameraZoom);
}

PulsarAnimationWidget::~PulsarAnimationWidget()
{
	if(m_quadricPulsarOrbitPlane) gluDeleteQuadric(m_quadricPulsarOrbitPlane);
	if(m_quadricPulsar) gluDeleteQuadric(m_quadricPulsar);
	if(m_quadricPulsarCone1) gluDeleteQuadric(m_quadricPulsarCone1);
	if(m_quadricPulsarCone2) gluDeleteQuadric(m_quadricPulsarCone2);
}

void PulsarAnimationWidget::initializeGL()
{
	glClearColor(0.0, 0.0, 0.0, 0.0);
	glClearDepth(1.0f);
	glDepthFunc(GL_LEQUAL);
	glEnable(GL_DEPTH_TEST);

	glShadeModel(GL_SMOOTH);
	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);

	GLfloat LightAmbient[] = { 0.3f, 0.3f, 0.3f, 1.0f };
	GLfloat LightDiffuse[] = { 1.0f, 1.0f, 1.0f, 1.0f };
	GLfloat LightSpecular[] = { 1.0f, 1.0f, 1.0f, 1.0f };
	GLfloat LightPosition[] = { 0.0f, 0.0f, 3.0f, 1.0f };
	GLfloat spot_direction[] = { 0.0, 0.0, -1.0 };

	glLightfv(GL_LIGHT0, GL_AMBIENT, LightAmbient);
	glLightfv(GL_LIGHT0, GL_DIFFUSE, LightDiffuse);
	glLightfv(GL_LIGHT0, GL_SPECULAR, LightSpecular);
	glLightfv(GL_LIGHT0, GL_POSITION, LightPosition);
	glLightf(GL_LIGHT0, GL_SPOT_CUTOFF, 50.0);
	glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION, spot_direction);
	glLightf(GL_LIGHT0, GL_SPOT_EXPONENT, 10.0);

	glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER, GL_TRUE);
	glEnable(GL_LIGHT0);
	glEnable(GL_LIGHTING);

	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	glEnable(GL_BLEND);

	m_quadricPulsarOrbitPlane = gluNewQuadric();
	m_quadricPulsar = gluNewQuadric();
    m_quadricPulsarCone1 = gluNewQuadric();
    m_quadricPulsarCone2 = gluNewQuadric();
    gluQuadricNormals(m_quadricPulsarOrbitPlane, GLU_SMOOTH);
    gluQuadricNormals(m_quadricPulsar, GLU_SMOOTH);
    gluQuadricNormals(m_quadricPulsarCone1, GLU_SMOOTH);
    gluQuadricNormals(m_quadricPulsarCone2, GLU_SMOOTH);
}

void PulsarAnimationWidget::resizeGL(int w, int h)
{
	glViewport(0, 0, w, h);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	gluPerspective(45.0f, (GLfloat)w / (GLfloat)h, 0.1f, 100.0f);

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
}

void PulsarAnimationWidget::paintGL()
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();

	gluLookAt(m_cameraPosX, m_cameraPosY, m_cameraPosZ,
			  0.0, 0.0, 0.0,
			  0.0, 1.0, 0.0);

	// TODO: should be located elsewhere
	static GLfloat no_mat[] = { 0.0, 0.0, 0.0, 1.0 };
	static GLfloat mat_diffuse[] = { 0.5, 0.5, 0.5, 1.0 };
	static GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
	static GLfloat low_shininess[] = { 5.0 };

	glMaterialfv(GL_FRONT, GL_AMBIENT, no_mat);
	glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
	glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
	glMaterialfv(GL_FRONT, GL_SHININESS, low_shininess);
	glMaterialfv(GL_FRONT, GL_EMISSION, no_mat);

	glPushMatrix();
		glTranslatef(sin((m_orbitRotationAngle + 180) * deg2rad) * m_companionOrbitRadius,
					 0.0f,
					 cos((m_orbitRotationAngle + 180) * deg2rad) * m_companionOrbitRadius);
		gluSphere(m_quadricPulsar, 1.0f, 32, 32);
	glPopMatrix();

	glPushMatrix();
		glTranslatef(sin(m_orbitRotationAngle * deg2rad) * m_pulsarOrbitRadius,
					 0.0f,
					 cos(m_orbitRotationAngle * deg2rad) * m_pulsarOrbitRadius);

		glPushMatrix();
			glRotatef(m_pulsarRotationAngle, 0.0f, 1.0f, 0.0f);
			glRotatef(m_pulsarSpinAxisInclination, 1.0f, 0.0f, 0.0f);
			gluSphere(m_quadricPulsar, 1.0f, 32, 32);
		glPopMatrix();

		// TODO: should be located elsewhere
		static GLfloat coneAmbient[] = { 1.0, 1.0, 0.0, 1.0 };
		static GLfloat coneDiffuse[] = { 1.0, 1.0, 0.0, 1.0 };
		static GLfloat coneSpecular[] = { 1.0, 1.0, 0.5, 1.0 };

		glMaterialfv(GL_FRONT, GL_AMBIENT, coneAmbient);
		glMaterialfv(GL_FRONT, GL_DIFFUSE, coneDiffuse);
		glMaterialfv(GL_FRONT, GL_SPECULAR, coneSpecular);

		glPushMatrix();
			glRotatef(m_pulsarRotationAngle - 90.0f, 0.0f, 1.0f, 0.0f);
			glRotatef(-m_pulsarMagneticAxisInclination - m_pulsarSpinAxisInclination + 90.0f, 1.0f, 0.0f, 0.0f);
			glTranslatef(0.0f, 0.0f, -4.0f);
			gluCylinder(m_quadricPulsarCone1, 0.5f, 0.0f, 3.0f, 32, 32);
		glPopMatrix();

		glPushMatrix();
			glRotatef(m_pulsarRotationAngle + 90.0f, 0.0f, 1.0f, 0.0f);
			glRotatef(m_pulsarMagneticAxisInclination + m_pulsarSpinAxisInclination - 90.0f, 1.0f, 0.0f, 0.0f);
			glTranslatef(0.0f, 0.0f, -4.0f);
			gluCylinder(m_quadricPulsarCone2, 0.5f, 0.0f, 3.0f, 32, 32);
		glPopMatrix();
	glPopMatrix();

	if(m_cameraInteraction) {
		static GLfloat pulsarOrbitAmbientDiffuse[] = { 1.0, 1.0, 1.0, 0.33 };
		glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, pulsarOrbitAmbientDiffuse);

		glPushMatrix();
			glRotatef(90.0f, 1.0f, 0.0f, 0.0f);
			gluDisk(m_quadricPulsarOrbitPlane,
					m_pulsarOrbitRadius * 0.9f,
					m_pulsarOrbitRadius * 1.1f,
					64, 1);
		glPopMatrix();
	}
}

void PulsarAnimationWidget::runAnimation()
{
	m_frameTimer.start(1000.0f / m_framesPerSecond);
}

void PulsarAnimationWidget::pauseAnimation()
{
	m_frameTimer.stop();
}

void PulsarAnimationWidget::stopAnimation()
{
	m_frameTimer.stop();
	resetParameters();

	updateGL();
}

void PulsarAnimationWidget::updateFrame()
{
	m_pulsarRotationAngle += m_pulsarRotationDelta;
	if(m_pulsarRotationAngle > 360) {
		m_pulsarRotationAngle = 0.0f;
	}
	m_orbitRotationAngle += m_orbitRotationDelta;
	if(m_orbitRotationAngle > 360) {
		m_orbitRotationAngle = 0.0f;
	}

	updateGL();
}

void PulsarAnimationWidget::mousePressEvent(QMouseEvent *event)
{
	Q_UNUSED(event);

	m_cameraInteraction = true;
	updateGL();
}

void PulsarAnimationWidget::mouseMoveEvent(QMouseEvent *event)
{
	Qt::MouseButtons buttons = event->buttons();
	if((buttons & Qt::LeftButton) == Qt::LeftButton) {
		if(m_mouseLastX != 0) {
			m_mouseAngleH -= (m_mouseLastX - event->x()) / 2;
			m_mouseAngleH = m_mouseAngleH < 360? m_mouseAngleH : 0;

		}
		if(m_mouseLastY != 0) {
			m_mouseAngleV -= (m_mouseLastY - event->y()) / 2;
			m_mouseAngleV = m_mouseAngleV < 90? m_mouseAngleV : 90;
			m_mouseAngleV = m_mouseAngleV > -90? m_mouseAngleV : -90;
		}

		m_mouseLastX = event->x();
		m_mouseLastY = event->y();
	}
	else if((buttons & Qt::RightButton) == Qt::RightButton) {
		if(m_mouseLastY != 0) {
			m_cameraZoom -= (m_mouseLastY - event->y()) / 2;
			m_cameraZoom = m_cameraZoom >= m_cameraZoomLBound? m_cameraZoom : m_cameraZoomLBound;
			updateCameraPosition(m_mouseAngleH, m_mouseAngleV, m_cameraZoom);
		}

		m_mouseLastY = event->y();
	}

	updateCameraPosition(m_mouseAngleH, m_mouseAngleV, m_cameraZoom);
}

void PulsarAnimationWidget::mouseReleaseEvent(QMouseEvent *event)
{
	Q_UNUSED(event);

	m_mouseLastX = 0;
	m_mouseLastY = 0;
	m_cameraInteraction = false;
	updateGL();
}

void PulsarAnimationWidget::updateCameraPosition(const int angleH, const int angleV, const float zoom)
{
	m_cameraPosX = sin(angleH * deg2rad) * zoom;
	m_cameraPosY = sin(angleV * deg2rad) * zoom;
	m_cameraPosZ = cos(angleH * deg2rad) * cos(fabs(angleV * deg2rad)) * zoom;

	updateGL();
}

void PulsarAnimationWidget::setFramePerSecond(const unsigned int fps)
{
	m_framesPerSecond = fps;
}

void PulsarAnimationWidget::setPulsarRotationDelta(const float frequency)
{
	m_pulsarRotationDelta = (360.0f * frequency) / m_framesPerSecond;
}

void PulsarAnimationWidget::setOrbitRotationDelta(const float frequency)
{
	m_orbitRotationDelta = (360.0f * frequency) / m_framesPerSecond;
}

void PulsarAnimationWidget::setOrbitRadius(const float radius)
{
	// for the time being both have the same orbit (mass)
	m_pulsarOrbitRadius = radius;
	m_companionOrbitRadius = radius;
}

void PulsarAnimationWidget::setPulsarSpinAxisInclination(const int degrees)
{
	m_pulsarSpinAxisInclination = degrees;

	updateGL();
}

void PulsarAnimationWidget::setPulsarMagneticAxisInclination(const int degrees)
{
	m_pulsarMagneticAxisInclination = degrees;

	updateGL();
}

void PulsarAnimationWidget::resetParameters()
{
	m_pulsarRotationAngle = 0.0f;
	m_orbitRotationAngle = 0.0f;
}