/******************************************************************************
 *   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().directRendering()) {
		qWarning("Sorry, no direct rendering support for animation...");
	}
	if(!format().doubleBuffer()) {
		qWarning("Sorry, no double buffering support for animation...");
	}
	if(!format().rgba()) {
		qWarning("Sorry, no RGBA support for animation...");
	}
	if(!format().alpha()) {
		qWarning("Sorry, no alpha channel support for animation...");
	}
	if(!format().sampleBuffers()) {
		qWarning("Sorry, no multisampling support for animation...");
	}

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

    m_quadricCompanionOrbitPlane = NULL;
    m_quadricCompanion = NULL;
    m_quadricPulsarOrbitPlane = NULL;
    m_quadricPulsar = NULL;
	m_quadricPulsarCone1 = NULL;
	m_quadricPulsarCone2 = NULL;
	m_quadricPulsarSpinAxis = NULL;
	m_quadricPulsarMagneticAxis = NULL;

	m_pulsarTexture = 0;
	m_backgroundTexture = 0;

	m_framesPerSecond = 25;

	resetParameters();

	m_pulsarMass = 1.4f;
	m_companionMass = 1.4f;

	m_showRotationAxes = false;
	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_quadricCompanionOrbitPlane) gluDeleteQuadric(m_quadricCompanionOrbitPlane);
	if(m_quadricCompanion) gluDeleteQuadric(m_quadricCompanion);
	if(m_quadricPulsarOrbitPlane) gluDeleteQuadric(m_quadricPulsarOrbitPlane);
	if(m_quadricPulsar) gluDeleteQuadric(m_quadricPulsar);
	if(m_quadricPulsarCone1) gluDeleteQuadric(m_quadricPulsarCone1);
	if(m_quadricPulsarCone2) gluDeleteQuadric(m_quadricPulsarCone2);
	if(m_quadricPulsarSpinAxis) gluDeleteQuadric(m_quadricPulsarSpinAxis);
	if(m_quadricPulsarMagneticAxis) gluDeleteQuadric(m_quadricPulsarMagneticAxis);

	if(m_pulsarTexture) deleteTexture(m_pulsarTexture);
	if(m_backgroundTexture) deleteTexture(m_backgroundTexture);
}

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_quadricCompanionOrbitPlane = gluNewQuadric();
	m_quadricCompanion = gluNewQuadric();
	m_quadricPulsarOrbitPlane = gluNewQuadric();
	m_quadricPulsar = gluNewQuadric();
    m_quadricPulsarCone1 = gluNewQuadric();
    m_quadricPulsarCone2 = gluNewQuadric();
    m_quadricPulsarSpinAxis = gluNewQuadric();
    m_quadricPulsarMagneticAxis = gluNewQuadric();

    gluQuadricNormals(m_quadricCompanionOrbitPlane, GLU_SMOOTH);
    gluQuadricNormals(m_quadricCompanion, GLU_SMOOTH);
    gluQuadricNormals(m_quadricPulsarOrbitPlane, GLU_SMOOTH);
    gluQuadricNormals(m_quadricPulsar, GLU_SMOOTH);
    gluQuadricNormals(m_quadricPulsarCone1, GLU_SMOOTH);
    gluQuadricNormals(m_quadricPulsarCone2, GLU_SMOOTH);
    gluQuadricNormals(m_quadricPulsarSpinAxis, GLU_SMOOTH);
    gluQuadricNormals(m_quadricPulsarMagneticAxis, GLU_SMOOTH);

    // load textures
    m_pulsarTexture = bindTexture(QImage(":/textures/resources/texture_pulsar.png"), GL_TEXTURE_2D, GL_RGBA);
    m_backgroundTexture = bindTexture(QImage(":/textures/resources/texture_background.png"), GL_TEXTURE_2D, GL_RGBA);

    // use mipmapped textures
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);

    // enable 2D mapping (s/t coordinates, sphere map won't rotate texture!)
    glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
    glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
}

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, 500.0f);

	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[] = { 2.5 };
	static GLfloat translucent[] = { 1.0, 1.0, 1.0, 0.33 };

	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);

	// draw companion
	glPushMatrix();
		glTranslatef(sin((m_orbitRotationAngle + 180) * deg2rad) * m_companionSemiMajorAxis,
					 0.0f,
					 cos((m_orbitRotationAngle + 180) * deg2rad) * m_companionSemiMajorAxis);
		gluSphere(m_quadricCompanion, 1.0f, 32, 32);
	glPopMatrix();

	// draw pulsar
	glPushMatrix();
		glTranslatef(sin(m_orbitRotationAngle * deg2rad) * m_pulsarSemiMajorAxis,
					 0.0f,
					 cos(m_orbitRotationAngle * deg2rad) * m_pulsarSemiMajorAxis);

		glPushMatrix();
			glRotatef(m_pulsarSpinAxisInclination, 0.0f, 0.0f, 1.0f);
			glRotatef(m_pulsarRotationAngle, 0.0f, 1.0f, 0.0f);

			// draw spin axis
			if(m_showRotationAxes) {
				glPushMatrix();
					glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, translucent);
					glRotatef(90.0f, 1.0f, 0.0f, 0.0f);
					glTranslatef(0.0f, 0.0f, -5.0f);
					gluCylinder(m_quadricPulsarSpinAxis, 0.05f, 0.05f, 10.0f, 32, 1);
				glPopMatrix();
			}

			// create texture coordinates and enable texturing
	        glEnable(GL_TEXTURE_GEN_S);
	        glEnable(GL_TEXTURE_GEN_T);
	        glBindTexture(GL_TEXTURE_2D, m_pulsarTexture);
	        glEnable(GL_TEXTURE_2D);

			glMaterialfv(GL_FRONT, GL_AMBIENT, no_mat);
			glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
			gluSphere(m_quadricPulsar, 1.0f, 32, 32);

			// disable texturing
	        glDisable(GL_TEXTURE_GEN_S);
	        glDisable(GL_TEXTURE_GEN_T);
	        glDisable(GL_TEXTURE_2D);
		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_SPECULAR, coneSpecular);

		// first cone
		glPushMatrix();
			glRotatef(90.0f, 1.0f, 0.0f, 0.0f);
			glRotatef(m_pulsarSpinAxisInclination, 0.0f, 1.0f, 0.0f);

			glRotatef(-m_pulsarRotationAngle - 90.0f, 0.0f, 0.0f, 1.0f);
			glRotatef(-m_pulsarMagneticAxisInclination, 1.0f, 0.0f, 0.0f);

			// draw magnetic axis (for both cones)
			if(m_showRotationAxes) {
				glPushMatrix();
					glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, translucent);
					glTranslatef(0.0f, 0.0f, -5.0f);
					gluCylinder(m_quadricPulsarMagneticAxis, 0.05f, 0.05f, 10.0f, 32, 1);
				glPopMatrix();
			}

			glTranslatef(0.0f, 0.0f, -4.0f);

			glMaterialfv(GL_FRONT, GL_AMBIENT, coneAmbient);
			glMaterialfv(GL_FRONT, GL_DIFFUSE, coneDiffuse);
			gluCylinder(m_quadricPulsarCone1, 0.5f, 0.0f, 3.0f, 32, 32);
		glPopMatrix();

		// second cone
		glPushMatrix();
			glRotatef(-90.0f, 1.0f, 0.0f, 0.0f);
			glRotatef(-m_pulsarSpinAxisInclination, 0.0f, 1.0f, 0.0f);

			glRotatef(m_pulsarRotationAngle - 90.0f, 0.0f, 0.0f, 1.0f);
			glRotatef(m_pulsarMagneticAxisInclination, 1.0f, 0.0f, 0.0f);

			glTranslatef(0.0f, 0.0f, -4.0f);

			glMaterialfv(GL_FRONT, GL_AMBIENT, coneAmbient);
			glMaterialfv(GL_FRONT, GL_DIFFUSE, coneDiffuse);
			gluCylinder(m_quadricPulsarCone2, 0.5f, 0.0f, 3.0f, 32, 32);
		glPopMatrix();
	glPopMatrix();

	// draw orbital planes
	if(m_cameraInteraction) {
		glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, translucent);

		// companion
		glPushMatrix();
			glRotatef(90.0f, 1.0f, 0.0f, 0.0f);
			glTranslatef(0.0f, 0.0f, 0.0f);
			gluDisk(m_quadricCompanionOrbitPlane,
					m_companionSemiMajorAxis - 0.25f,
					m_companionSemiMajorAxis + 0.25f,
					64, 1);
		glPopMatrix();

		// pulsar
		glPushMatrix();
			glRotatef(90.0f, 1.0f, 0.0f, 0.0f);
			glTranslatef(0.0f, 0.0f, 0.1f);
			gluDisk(m_quadricPulsarOrbitPlane,
					m_pulsarSemiMajorAxis - 0.25f,
					m_pulsarSemiMajorAxis + 0.25f,
					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();

	emit pulsarAnimationStep(m_pulsarRotationDelta);
}

void PulsarAnimationWidget::showRotationAxes(bool enabled)
{
	m_showRotationAxes = enabled;

	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::setPulsarSemiMajorAxis(const float length)
{
	m_pulsarSemiMajorAxis = length;
	m_companionSemiMajorAxis = (m_pulsarMass/m_companionMass) * m_pulsarSemiMajorAxis;
	updateOrbitPeriod();

	updateGL();
}

void PulsarAnimationWidget::setCompanionMass(const float mass)
{
	m_companionMass = mass;
	updateOrbitRadii();

	updateGL();
}

void PulsarAnimationWidget::setPulsarMass(const float mass)
{
	m_pulsarMass = mass;
	updateOrbitRadii();

	updateGL();
}

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

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

	updateGL();
}

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

	updateGL();
}

void PulsarAnimationWidget::updateOrbitPeriod()
{
	m_orbitalPeriod = 3.1553e7 * sqrt(
						(pow(m_pulsarSemiMajorAxis,3) * pow(m_pulsarMass+m_companionMass,2)) /
						 pow(m_companionMass,3)
					  );

	// visual correction factor (increase orbital momentum)
	double visualCorrection = 1e-8;

	m_orbitRotationDelta  = (360.0 / (m_orbitalPeriod*visualCorrection)) / m_framesPerSecond;
}

void PulsarAnimationWidget::updateOrbitRadii()
{
	m_pulsarSemiMajorAxis = 1.0015e-5 * pow(
								(pow(m_orbitalPeriod,2) * pow(m_companionMass,3)) /
								 pow(m_pulsarMass+m_companionMass,2),
								 1.0/3.0
							);

	m_companionSemiMajorAxis = (m_pulsarMass/m_companionMass) * m_pulsarSemiMajorAxis;

	emit pulsarSemiMajorAxisUpdated(m_pulsarSemiMajorAxis);
}

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

	emit pulsarAnimationReset();
}