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#include "glwidget.h"

#include <QPainter>

#include <math.h>

#include "bubble.h"

const int bubbleNum = 8;

inline void CrossProduct(qreal &xOut, qreal &yOut, qreal &zOut, qreal x1, qreal y1, qreal z1, qreal x2, qreal y2, qreal z2)

{

   xOut = y1 * z2 - z1 * y2;

   yOut = z1 * x2 - x1 * z2;

   zOut = x1 * y2 - y1 * x2;

}

inline void Normalize(qreal &x, qreal &y, qreal &z)

{

    qreal l = sqrt(x*x + y*y + z*z);

    x = x / l;

    y = y / l;

    z = z / l;

}

GLWidget::GLWidget(QWidget *parent)

    : QGLWidget(parent)

{

    qtLogo = true;

    createdVertices = 0;

    createdNormals = 0;

    m_vertexNumber = 0;

    frames = 0;

    setAttribute(Qt::WA_PaintOnScreen);

    setAttribute(Qt::WA_NoSystemBackground);

    setAutoBufferSwap(false);

    m_showBubbles = true;

}

GLWidget::~GLWidget()

{

  if (createdVertices)

      delete[] createdVertices;

  if (createdNormals)

      delete[] createdNormals;

}

void GLWidget::setScaling(int scale) {

    if (scale > 50)

        m_fScale = 1 + qreal(scale -50) / 50 * 0.5;

    else if (scale < 50)

        m_fScale =  1- (qreal(50 - scale) / 50 * 1/2);

    else 

      m_fScale = 1;

}

void GLWidget::setLogo() {

    qtLogo = true;

}

void GLWidget::setTexture() {

    qtLogo = false;

}

void GLWidget::showBubbles(bool bubbles)

{

   m_showBubbles = bubbles;

}

//! [2]

void GLWidget::paintQtLogo()

{

    glDisable(GL_TEXTURE_2D);

    glEnableClientState(GL_VERTEX_ARRAY);

    glVertexPointer(3,GL_FLOAT,0, createdVertices);

    glEnableClientState(GL_NORMAL_ARRAY);

    glNormalPointer(GL_FLOAT,0,createdNormals);

    glDrawArrays(GL_TRIANGLES, 0, m_vertexNumber / 3);

}

//! [2]

void GLWidget::paintTexturedCube()

{

    glEnable(GL_TEXTURE_2D);

    glBindTexture(GL_TEXTURE_2D, m_uiTexture);

    GLfloat afVertices[] = {

        -0.5, 0.5, 0.5, 0.5,-0.5,0.5,-0.5,-0.5,0.5,

        0.5, -0.5, 0.5, -0.5,0.5,0.5,0.5,0.5,0.5,

        -0.5, -0.5, -0.5, 0.5,-0.5,-0.5,-0.5,0.5,-0.5,

        0.5, 0.5, -0.5, -0.5,0.5,-0.5,0.5,-0.5,-0.5,

        0.5, -0.5, -0.5, 0.5,-0.5,0.5,0.5,0.5,-0.5,

        0.5, 0.5, 0.5, 0.5,0.5,-0.5,0.5,-0.5,0.5,

        -0.5, 0.5, -0.5, -0.5,-0.5,0.5,-0.5,-0.5,-0.5,

        -0.5, -0.5, 0.5, -0.5,0.5,-0.5,-0.5,0.5,0.5,

        0.5, 0.5,  -0.5, -0.5, 0.5,  0.5,  -0.5,  0.5,  -0.5,

        -0.5,  0.5,  0.5,  0.5,  0.5,  -0.5, 0.5, 0.5,  0.5,

        -0.5,  -0.5, -0.5, -0.5, -0.5, 0.5,  0.5, -0.5, -0.5,

        0.5, -0.5, 0.5,  0.5,  -0.5, -0.5, -0.5,  -0.5, 0.5

    };

    glEnableClientState(GL_VERTEX_ARRAY);

    glVertexPointer(3,GL_FLOAT,0,afVertices);

    GLfloat afTexCoord[] = {

        0.0f,0.0f, 1.0f,1.0f, 1.0f,0.0f,

        1.0f,1.0f, 0.0f,0.0f, 0.0f,1.0f,

        1.0f,1.0f, 1.0f,0.0f, 0.0f,1.0f,

        0.0f,0.0f, 0.0f,1.0f, 1.0f,0.0f,

        1.0f,1.0f, 1.0f,0.0f, 0.0f,1.0f,

        0.0f,0.0f, 0.0f,1.0f, 1.0f,0.0f,

        0.0f,0.0f, 1.0f,1.0f, 1.0f,0.0f,

        1.0f,1.0f, 0.0f,0.0f, 0.0f,1.0f,

        0.0f,1.0f, 1.0f,0.0f, 1.0f,1.0f,

        1.0f,0.0f, 0.0f,1.0f, 0.0f,0.0f,

        1.0f,0.0f, 1.0f,1.0f, 0.0f,0.0f,

        0.0f,1.0f, 0.0f,0.0f, 1.0f,1.0f

    };

    glEnableClientState(GL_TEXTURE_COORD_ARRAY);

    glTexCoordPointer(2,GL_FLOAT,0,afTexCoord);

    GLfloat afNormals[] = {

        0,0,-1, 0,0,-1, 0,0,-1,

        0,0,-1, 0,0,-1, 0,0,-1,

        0,0,1, 0,0,1, 0,0,1,

        0,0,1, 0,0,1, 0,0,1,

        -1,0,0, -1,0,0, -1,0,0,

        -1,0,0, -1,0,0, -1,0,0,

        1,0,0, 1,0,0, 1,0,0,

        1,0,0, 1,0,0, 1,0,0,

        0,-1,0, 0,-1,0, 0,-1,0,

        0,-1,0, 0,-1,0, 0,-1,0,

        0,1,0, 0,1,0, 0,1,0,

        0,1,0, 0,1,0, 0,1,0

    };

    glEnableClientState(GL_NORMAL_ARRAY);

    glNormalPointer(GL_FLOAT,0,afNormals);

    glDrawArrays(GL_TRIANGLES, 0, 36);

}

void GLWidget::initializeGL ()

{

    glClearColor(0.1f, 0.1f, 0.2f, 1.0f);

    glEnable(GL_TEXTURE_2D);

    glGenTextures(1, &m_uiTexture);

    m_uiTexture = bindTexture(QImage(":/qt.png"));

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );

    glEnable(GL_LIGHTING);

    glEnable(GL_LIGHT0);

    GLfloat aLightPosition[] = {0.0f,0.3f,1.0f,0.0f};

    glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION, aLightPosition);

    m_fAngle = 0;

    m_fScale = 1;

    createGeometry();

    createBubbles(bubbleNum - bubbles.count());

}

void GLWidget::paintGL()

{

    createBubbles(bubbleNum - bubbles.count());

//! [3]    

    QPainter painter;

    painter.begin(this);

    glMatrixMode(GL_PROJECTION);

    glPushMatrix();

    glLoadIdentity();

//! [3]    

//! [4]    

    glMatrixMode(GL_MODELVIEW);

    glPushMatrix();

    glMatrixMode(GL_TEXTURE);

    glPushMatrix();

    //Since OpenGL ES does not support glPush/PopAttrib(GL_ALL_ATTRIB_BITS) 

    //we have to take care of the states ourselves

    glClearColor(0.1f, 0.1f, 0.2f, 1.0f);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glEnable(GL_TEXTURE_2D);

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );

    glEnable(GL_LIGHTING);

    glEnable(GL_LIGHT0);

    glShadeModel(GL_FLAT);

    glFrontFace(GL_CW);

    glCullFace(GL_FRONT);

    glEnable(GL_CULL_FACE);

    glEnable(GL_DEPTH_TEST);

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity();

    glRotatef(m_fAngle, 0.0f, 1.0f, 0.0f);

    glRotatef(m_fAngle, 1.0f, 0.0f, 0.0f);

    glRotatef(m_fAngle, 0.0f, 0.0f, 1.0f);

    glScalef(m_fScale, m_fScale,m_fScale);

    glTranslatef(0.0f,-0.2f,0.0f);

    GLfloat matDiff[] = {0.40f, 1.0f, 0.0f, 1.0f};

    glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, matDiff);

    if (qtLogo)

        paintQtLogo();

    else

        paintTexturedCube();

//! [4]    

//![5]

    glMatrixMode(GL_MODELVIEW);

    glPopMatrix();

    glMatrixMode(GL_PROJECTION);

    glPopMatrix();

    glMatrixMode(GL_TEXTURE);

    glPopMatrix();

    glDisable(GL_LIGHTING);

    glDisable(GL_LIGHT0);

    glDisable(GL_DEPTH_TEST);

    glDisable(GL_CULL_FACE);

//![5]

//! [6]

    if (m_showBubbles)

        foreach (Bubble *bubble, bubbles) {

            bubble->drawBubble(&painter);

    }

//! [6]

//! [7]

    QString framesPerSecond;

    framesPerSecond.setNum(frames /(time.elapsed() / 1000.0), 'f', 2);

    painter.setPen(Qt::white);

    painter.drawText(20, 40, framesPerSecond + " fps");

    painter.end();

//! [7]

//! [8]

    swapBuffers();

//! [8]

    QMutableListIterator<Bubble*> iter(bubbles);

    while (iter.hasNext()) {

        Bubble *bubble = iter.next();

        bubble->move(rect());

    }

    if (!(frames % 100)) {

        time.start();

        frames = 0;

    }

    m_fAngle += 1.0f;

    frames ++;

}

void GLWidget::createBubbles(int number)

{

    for (int i = 0; i < number; ++i) {

        QPointF position(width()*(0.1 + (0.8*qrand()/(RAND_MAX+1.0))),

                        height()*(0.1 + (0.8*qrand()/(RAND_MAX+1.0))));

        qreal radius = qMin(width(), height())*(0.0175 + 0.0875*qrand()/(RAND_MAX+1.0));

        QPointF velocity(width()*0.0175*(-0.5 + qrand()/(RAND_MAX+1.0)),

                        height()*0.0175*(-0.5 + qrand()/(RAND_MAX+1.0)));

        bubbles.append(new Bubble(position, radius, velocity));

    }

}

void GLWidget::createGeometry()

{

    vertices.clear();

    normals.clear();

    qreal x1 = +0.06f;

    qreal y1 = -0.14f;

    qreal x2 = +0.14f;

    qreal y2 = -0.06f;

    qreal x3 = +0.08f;

    qreal y3 = +0.00f;

    qreal x4 = +0.30f;

    qreal y4 = +0.22f;

    quad(x1, y1, x2, y2, y2, x2, y1, x1);

    quad(x3, y3, x4, y4, y4, x4, y3, x3);

    extrude(x1, y1, x2, y2);

    extrude(x2, y2, y2, x2);

    extrude(y2, x2, y1, x1);

    extrude(y1, x1, x1, y1);

    extrude(x3, y3, x4, y4);

    extrude(x4, y4, y4, x4);

    extrude(y4, x4, y3, x3);

    const qreal Pi = 3.14159f;

    const int NumSectors = 100;

    for (int i = 0; i < NumSectors; ++i) {

        qreal angle1 = (i * 2 * Pi) / NumSectors;

        qreal x5 = 0.30 * sin(angle1);

        qreal y5 = 0.30 * cos(angle1);

        qreal x6 = 0.20 * sin(angle1);

        qreal y6 = 0.20 * cos(angle1);

        qreal angle2 = ((i + 1) * 2 * Pi) / NumSectors;

        qreal x7 = 0.20 * sin(angle2);

        qreal y7 = 0.20 * cos(angle2);

        qreal x8 = 0.30 * sin(angle2);

        qreal y8 = 0.30 * cos(angle2);

        quad(x5, y5, x6, y6, x7, y7, x8, y8);

        extrude(x6, y6, x7, y7);

        extrude(x8, y8, x5, y5);

    }

//! [1]

    m_vertexNumber = vertices.size();

    createdVertices = new GLfloat[m_vertexNumber];

    createdNormals = new GLfloat[m_vertexNumber];

    for (int i = 0;i < m_vertexNumber;i++) {

      createdVertices[i] = vertices.at(i) * 2;

      createdNormals[i] = normals.at(i);

    }

    vertices.clear();

    normals.clear();

}

//! [1]

//! [0]

void GLWidget::quad(qreal x1, qreal y1, qreal x2, qreal y2, qreal x3, qreal y3, qreal x4, qreal y4)

{

    qreal nx, ny, nz;

    vertices << x1 << y1 << -0.05f;

    vertices << x2 << y2 << -0.05f;

    vertices << x4 << y4 << -0.05f;

    vertices << x3 << y3 << -0.05f;

    vertices << x4 << y4 << -0.05f;

    vertices << x2 << y2 << -0.05f;

    CrossProduct(nx, ny, nz, x2 - x1, y2 - y1, 0, x4 - x1, y4 - y1, 0);

    Normalize(nx, ny, nz);

    normals << nx << ny << nz;

    normals << nx << ny << nz;

    normals << nx << ny << nz;

    normals << nx << ny << nz;

    normals << nx << ny << nz;

    normals << nx << ny << nz;

    vertices << x4 << y4 << 0.05f;

    vertices << x2 << y2 << 0.05f;

    vertices << x1 << y1 << 0.05f;

    vertices << x2 << y2 << 0.05f;

    vertices << x4 << y4 << 0.05f;

    vertices << x3 << y3 << 0.05f;

    CrossProduct(nx, ny, nz, x2 - x4, y2 - y4, 0, x1 - x4, y1 - y4, 0);

    Normalize(nx, ny, nz);

    normals << nx << ny << nz;

    normals << nx << ny << nz;

    normals << nx << ny << nz;

    normals << nx << ny << nz;

    normals << nx << ny << nz;

    normals << nx << ny << nz;

}

//! [0]

void GLWidget::extrude(qreal x1, qreal y1, qreal x2, qreal y2)

{

    qreal nx, ny, nz;

    vertices << x1 << y1 << +0.05f;

    vertices << x2 << y2 << +0.05f;

    vertices << x1 << y1 << -0.05f;

    vertices << x2 << y2 << -0.05f;

    vertices << x1 << y1 << -0.05f;

    vertices << x2 << y2 << +0.05f;

    CrossProduct(nx, ny, nz, x2 - x1, y2 - y1, 0.0f, 0.0f, 0.0f, -0.1f);

    Normalize(nx, ny, nz);

    normals << nx << ny << nz;

    normals << nx << ny << nz;

    normals << nx << ny << nz;

    normals << nx << ny << nz;

    normals << nx << ny << nz;

    normals << nx << ny << nz;

}