/******************************************************************************
 *   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 double PulsarAnimationWidget::deg2rad = PI/180.0;

PulsarAnimationWidget::PulsarAnimationWidget(QWidget *parent) :
    QGLWidget(QGLFormat(QGL::AlphaChannel | QGL::SampleBuffers), parent),

    m_pulseProfile(360, 0.0)
{
    QString msgThis = tr("3D animation");
    if(!format().directRendering()) {
        QString msg = tr("Sorry, no direct rendering support for %1...");
        qWarning() << msg.arg(msgThis);
    }
    if(!format().doubleBuffer()) {
        QString msg = tr("Sorry, no double buffering support for %1...");
        qWarning() << msg.arg(msgThis);
    }
    if(!format().rgba()) {
        QString msg = tr("Sorry, no RGBA support for %1...");
        qWarning() << msg.arg(msgThis);
    }
    if(!format().alpha()) {
        QString msg = tr("Sorry, no alpha channel support for %1...");
        qWarning() << msg.arg(msgThis);
    }
    if(!format().sampleBuffers()) {
        QString msg = tr("Sorry, no multisampling support for %1...");
        qWarning() << msg.arg(msgThis);
    }

    // initialize quadric pointers
    m_quadricVirgoh = NULL;
    m_quadricVirgov = NULL;
    m_quadricEarth = NULL;
    m_quadricLLOh = NULL;
    m_quadricLLOv = NULL;
    m_quadricSourcePlane = NULL;
    m_quadricSourcePlaneNormal = NULL;
    m_quadricSourcePlaneNormalCap = NULL;
    m_quadricLHOv = NULL;
    m_quadricLHOh = NULL;

    // initialize texture pointers
    m_beamTexture = 0;

    // initial parameters (have to match GUI!)
    m_LHOAngle = 180;
    m_LLOAngle = -100;
    m_VirgoAngle = 165;
    m_sourceIota = 0.0;
    m_sourceInclination = 0;

    m_earthRadius = 3.0;

    // initial view features
    m_cameraInteraction = false;

    // initial view settings
    m_mouseAngleH = 0.0;
    m_mouseAngleV = 0.0;
    m_cameraZoom = 100.0;
    m_cameraZoomLBound = 10.0;
    m_cameraZoomUBound = 4500.0;
    m_mouseLastX = 0;
    m_mouseLastY = 0;

    // update camera based on settings above
    updateCameraPosition(m_mouseAngleH, m_mouseAngleV, m_cameraZoom);
}

PulsarAnimationWidget::~PulsarAnimationWidget()
{
    if(m_quadricVirgoh) gluDeleteQuadric(m_quadricVirgoh);
    if(m_quadricVirgov) gluDeleteQuadric(m_quadricVirgov);
    if(m_quadricEarth) gluDeleteQuadric(m_quadricEarth);
    if(m_quadricLLOh) gluDeleteQuadric(m_quadricLLOh);
    if(m_quadricLLOv) gluDeleteQuadric(m_quadricLLOv);
    if(m_quadricSourcePlane) gluDeleteQuadric(m_quadricSourcePlane);
    if(m_quadricSourcePlaneNormal) gluDeleteQuadric(m_quadricSourcePlaneNormal);
    if(m_quadricSourcePlaneNormalCap) gluDeleteQuadric(m_quadricSourcePlaneNormalCap);
    if(m_quadricLHOv) gluDeleteQuadric(m_quadricLHOv);
    if(m_quadricLHOh) gluDeleteQuadric(m_quadricLHOh);

    if(m_beamTexture) deleteTexture(m_beamTexture);
}

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

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

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

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

    m_quadricVirgoh = gluNewQuadric();
    m_quadricVirgov = gluNewQuadric();
    m_quadricEarth = gluNewQuadric();
    m_quadricLLOh = gluNewQuadric();
    m_quadricLLOv = gluNewQuadric();
    m_quadricSourcePlane = gluNewQuadric();
    m_quadricSourcePlaneNormal = gluNewQuadric();
    m_quadricSourcePlaneNormalCap = gluNewQuadric();
    m_quadricLHOv = gluNewQuadric();
    m_quadricLHOh = gluNewQuadric();

    gluQuadricNormals(m_quadricVirgoh, GLU_SMOOTH);
    gluQuadricNormals(m_quadricVirgov, GLU_SMOOTH);
    gluQuadricNormals(m_quadricEarth, GLU_SMOOTH);
    gluQuadricNormals(m_quadricLLOh, GLU_SMOOTH);
    gluQuadricNormals(m_quadricLLOv, GLU_SMOOTH);
    gluQuadricNormals(m_quadricSourcePlane, GLU_SMOOTH);
    gluQuadricNormals(m_quadricSourcePlaneNormal, GLU_SMOOTH);
    gluQuadricNormals(m_quadricSourcePlaneNormalCap, GLU_SMOOTH);
    gluQuadricNormals(m_quadricLHOv, GLU_SMOOTH);
    gluQuadricNormals(m_quadricLHOh, GLU_SMOOTH);

    // query max texture size (estimate)
    GLint maxTextureSize;
    glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxTextureSize);

    // prepare and check beam texture
    QImage beamTexture(":/textures/resources/World-Map-7.jpg");

    // bind textures
    m_beamTexture = bindTexture(beamTexture, 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);
}

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

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();

    gluPerspective(4.5, (GLfloat)w / (GLfloat)h, 0.1, 5000.0);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
}

void PulsarAnimationWidget::paintGL()
{
    GLfloat x,y,angle;

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

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

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

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

    // save current state (the following is using parallel projection)
    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
    {
        glLoadIdentity();
        glOrtho(0, width(), 0, height(), 0.1, 501.0);
        glMatrixMode(GL_MODELVIEW);
        glPushMatrix();
        {
            glLoadIdentity();

            // draw backdrop (independent parallel projection)
            glColor3f(1.0, 1.0, 1.0f);
            glTranslatef(0.0, 0.0, -501.0);

            // restore original state
            glMatrixMode(GL_PROJECTION);
        }
        glPopMatrix();
        glMatrixMode(GL_MODELVIEW);
    }
    glPopMatrix();

    // draw earth
    glPushMatrix();
    {
        glRotatef(130, 0.0, 1.0, 0.0);
        glPushMatrix();
        {
            glRotatef(90, 1.0, 0.0, 0.0);
            glRotatef(180, 1.0, 1.0, 0.0);

            // create texture coordinates and enable texturing
            gluQuadricTexture(m_quadricEarth, GL_TRUE);
            glBindTexture(GL_TEXTURE_2D, m_beamTexture);
            glEnable(GL_TEXTURE_2D);

            gluSphere(m_quadricEarth, m_earthRadius, 32, 32);
        }
        glPopMatrix();
    }
    glPopMatrix();

    // draw LHO
    glPushMatrix();
    {
        glColor3f(1.0f, 1.0f, 1.0f);

        glRotatef(-81, 1.0, 1.0, 0.0);
        glTranslatef(0.0, 0.0, m_earthRadius);
        glRotatef(m_LHOAngle, 0.0, 0.0, 1.0);
        glPushMatrix();
        {
            glRotatef(90, 0.0, 1.0, 0.0);
            gluCylinder(m_quadricLHOh, 0.010, 0.010, 0.20, 32, 1);
        }
        glPopMatrix();

        glPushMatrix();
        {
            glRotatef(90, 0.0, 1.0, 0.0);
            glRotatef(90, 1.0, 0.0, 0.0);
            glColor3f(0.5f, 0.5f, 1.0f);
            gluCylinder(m_quadricLHOv, 0.010, 0.010, 0.20, 32, 1);
        }
        glPopMatrix();
    }
    glPopMatrix();

    // draw LLO
    glPushMatrix();
    {
        glColor3f(1.0f, 1.0f, 1.0f);

        glRotatef(-2, 0.0, 1.0, 0.0);
        glRotatef(5, 1.0, 0.0, 0.0);
        glRotatef(-60, 1.0, 1.0, 0.0);
        glTranslatef(0.0, 0.0, m_earthRadius);
        glRotatef(m_LLOAngle, 0.0, 0.0, 1.0);
        glPushMatrix();
        {
            glRotatef(90, 0.0, 1.0, 0.0);
            gluCylinder(m_quadricLLOh, 0.010, 0.010, 0.20, 32, 1);
        }
        glPopMatrix();

        glPushMatrix();
        {
            glRotatef(90, 0.0, 1.0, 0.0);
            glRotatef(90, 1.0, 0.0, 0.0);
            glColor3f(1.0f, 0.5f, 0.5f);
            gluCylinder(m_quadricLLOv, 0.010, 0.010, 0.20, 32, 1);
        }
        glPopMatrix();
    }
    glPopMatrix();

    // draw Virgo
    glPushMatrix();
    {
        glColor3f(1.0f, 1.0f, 1.0f);

        glRotatef(50, 0.0, 1.0, 0.0);
        glRotatef(-43, 1.0, 0.0, 0.0);
        glTranslatef(0.0, 0.0, m_earthRadius);
        glRotatef(m_VirgoAngle, 0.0, 0.0, 1.0);
        glPushMatrix();
        {
            glRotatef(90, 0.0, 1.0, 0.0);
            gluCylinder(m_quadricVirgoh, 0.010, 0.010, 0.20, 32, 1);
        }
        glPopMatrix();

        glPushMatrix();
        {
            glRotatef(90, 0.0, 1.0, 0.0);
            glRotatef(90, 1.0, 0.0, 0.0);
            glColor3f(0.5f, 1.0f, 0.5f);
            gluCylinder(m_quadricVirgov, 0.010, 0.010, 0.20, 32, 1);
        }
        glPopMatrix();
    }
    glPopMatrix();

    // draw source
    glPushMatrix();
    {
        glTranslatef(3.0,
                     3.0,
                     -3.0);

        glRotatef(m_sourceInclination, 0.0, 1.0, 0.0);
        glRotatef(-45, 0.0, 1.0, 0.0);
        glRotatef(90, 1.0, 0.0, 0.0);

        glPushMatrix();
        {
            glRotatef(m_sourceIota, 1.0, 0.0, 0.0);
            glRotatef(-45, 1.0, 0.0, 0.0);

            // draw source plane normal
            glColor3f(1.0f, 0.0f, 0.0f);
            glPushMatrix();
            {
                glTranslatef(0.0, 0.0, -1.0);
                gluCylinder(m_quadricSourcePlaneNormal, 0.020, 0.020, 1.5, 32, 1);
            }
            glPopMatrix();
            glPushMatrix();
            {
                glTranslatef(0.0, 0.0, -1.0);
                gluDisk(m_quadricSourcePlaneNormalCap, 0, 0.020, 32, 8);
            }
            glPopMatrix();
            glPushMatrix();
            {
                glTranslatef(0.0, 0.0, 0.5f);
                glBegin(GL_TRIANGLE_FAN);
                {
                    // Pinnacle of cone is shared vertex for fan, moved up z-axis
                    // to produce a cone instead of a circle
                    glVertex3f(0.0f, 0.0f, 0.5f);

                    // Loop around in a circle and specify even points along the circle
                    // as the vertices of the triangle fan (32 sections)
                    for(angle = 0.0f; angle < (2.0f*PI); angle += (PI/32.0f))
                    {
                        // Calculate x and y position of the next vertex
                        x = 0.1f * sin(angle);
                        y = 0.1f * cos(angle);

                        // Specify the next vertex for the triangle fan
                        glVertex2f(x, y);
                    }
                }
                glEnd();
            }
            glPopMatrix();

            // draw disc
            glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, translucent);
            glEnable(GL_LIGHTING);

            glPushMatrix();
            {
                gluDisk(m_quadricSourcePlane,
                        0,
                        1.0,
                        64, 1);
            }
            glPopMatrix();

            glDisable(GL_LIGHTING);
        }
        glPopMatrix();
    }
    glPopMatrix();

    // save current state (the following is using parallel projection)
    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
    {
        glLoadIdentity();
        glOrtho(0, width(), 0, height(), 0.1, 501.0);
        glMatrixMode(GL_MODELVIEW);
        glPushMatrix();
        {
            glLoadIdentity();

            // draw copyright info last (appears in front of everything)
            glColor4f(1.0f, 1.0f, 1.0f, 0.5f);
            QFont font;
            font.setPointSize(11);
            font.setBold(true);
            font.setFamily("Arial");
            font.setStyleStrategy((QFont::StyleStrategy) (QFont::OpenGLCompatible | QFont::PreferQuality));
            renderText(10, 25, -100, QString("Copyright %1 2017").arg(QChar(0x00A9)), font);
            renderText(10, 10, -100, tr("Max Planck Institute for Gravitational Physics"), font);

            // restore original state
            glMatrixMode(GL_PROJECTION);
        }
        glPopMatrix();
        glMatrixMode(GL_MODELVIEW);
    }
    glPopMatrix();
}

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());
            m_mouseAngleH = m_mouseAngleH < 360 ? m_mouseAngleH : 0;
            m_mouseAngleH = m_mouseAngleH >=  0 ? m_mouseAngleH : 359;
        }
        if(m_mouseLastY != 0) {
            m_mouseAngleV -= (m_mouseLastY - event->y());
            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());
            m_cameraZoom = m_cameraZoom >= m_cameraZoomLBound ? m_cameraZoom : m_cameraZoomLBound;
            m_cameraZoom = m_cameraZoom >= m_cameraZoomUBound ? m_cameraZoomUBound : 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::showEvent(QShowEvent *event)
{
    Q_UNUSED(event);

    // update and propagate pulse profile
    updatePulseProfile();
}

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

    updatePulseProfile();

    updateGL();
}

void PulsarAnimationWidget::setSourceInclination(const double degrees)
{
    m_sourceInclination = degrees;
    updatePulseProfile();

    updateGL();
}

void PulsarAnimationWidget::setLHOAngle(const double degrees)
{
    m_LHOAngle = degrees + 180;
    updatePulseProfile();

    updateGL();
}

void PulsarAnimationWidget::setLLOAngle(const double degrees)
{
    m_LLOAngle = degrees - 100;
    updatePulseProfile();

    updateGL();
}

void PulsarAnimationWidget::setVirgoAngle(const int degrees)
{
    m_VirgoAngle = degrees + 165;
    updatePulseProfile();

    updateGL();
}

void PulsarAnimationWidget::setSourceIota(const int degrees)
{
    m_sourceIota = degrees;
    updatePulseProfile();

    updateGL();
}

void PulsarAnimationWidget::getCameraPosition(double& cameraAngleH, double& cameraAngleV, double& cameraZoom)
{
    cameraAngleH = m_mouseAngleH;
    cameraAngleV = m_mouseAngleV;
    cameraZoom = m_cameraZoom;
}

void PulsarAnimationWidget::resetCameraPosition(const double angleH, const double angleV, const double zoom)
{
    m_mouseAngleH = angleH;
    m_mouseAngleV = angleV;
    m_cameraZoom = zoom;

    updateCameraPosition(m_mouseAngleH, m_mouseAngleV, m_cameraZoom);
}

void PulsarAnimationWidget::updatePulseProfile()
{
    for(int x = 0; x < 360; ++x) {
        m_pulseProfile[x] = 0;
    }

    // propagate new profile
    emit pulseProfileUpdated(m_pulseProfile);
}