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#include "glwidget.h"

#include <QPainter>

#include <QPaintEngine>

#include <math.h>

#include "bubble.h"

const int bubbleNum = 8;

GLWidget::GLWidget(QWidget *parent)

    : QGLWidget(parent)

{

    qtLogo = true;

    frames = 0;

    setAttribute(Qt::WA_PaintOnScreen);

    setAttribute(Qt::WA_NoSystemBackground);

    setAutoBufferSwap(false);

    m_showBubbles = true;

#ifndef Q_WS_QWS

    setMinimumSize(300, 250);

#endif

}

GLWidget::~GLWidget()

{

}

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;

}

void GLWidget::paintQtLogo()

{

    program1.enableAttributeArray(normalAttr1);

    program1.enableAttributeArray(vertexAttr1);

    program1.setAttributeArray(vertexAttr1, vertices.constData());

    program1.setAttributeArray(normalAttr1, normals.constData());

    glDrawArrays(GL_TRIANGLES, 0, vertices.size());

    program1.disableAttributeArray(normalAttr1);

    program1.disableAttributeArray(vertexAttr1);

}

void GLWidget::paintTexturedCube()

{

    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

    };

    program2.setAttributeArray(vertexAttr2, afVertices, 3);

    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

    };

    program2.setAttributeArray(texCoordAttr2, afTexCoord, 2);

    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

    };

    program2.setAttributeArray(normalAttr2, afNormals, 3);

    program2.setUniformValue(textureUniform2, 0);    // use texture unit 0

    program2.enableAttributeArray(vertexAttr2);

    program2.enableAttributeArray(normalAttr2);

    program2.enableAttributeArray(texCoordAttr2);

    glDrawArrays(GL_TRIANGLES, 0, 36);

    program2.disableAttributeArray(vertexAttr2);

    program2.disableAttributeArray(normalAttr2);

    program2.disableAttributeArray(texCoordAttr2);

}

void GLWidget::initializeGL ()

{

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

    glGenTextures(1, &m_uiTexture);

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

    QGLShader *vshader1 = new QGLShader(QGLShader::Vertex, this);

    const char *vsrc1 =

        "attribute highp vec4 vertex;\n"

        "attribute mediump vec3 normal;\n"

        "uniform mediump mat4 matrix;\n"

        "varying mediump vec4 color;\n"

        "void main(void)\n"

        "{\n"

        "    vec3 toLight = normalize(vec3(0.0, 0.3, 1.0));\n"

        "    float angle = max(dot(normal, toLight), 0.0);\n"

        "    vec3 col = vec3(0.40, 1.0, 0.0);\n"

        "    color = vec4(col * 0.2 + col * 0.8 * angle, 1.0);\n"

        "    color = clamp(color, 0.0, 1.0);\n"

        "    gl_Position = matrix * vertex;\n"

        "}\n";

    vshader1->compileSourceCode(vsrc1);

    QGLShader *fshader1 = new QGLShader(QGLShader::Fragment, this);

    const char *fsrc1 =

        "varying mediump vec4 color;\n"

        "void main(void)\n"

        "{\n"

        "    gl_FragColor = color;\n"

        "}\n";

    fshader1->compileSourceCode(fsrc1);

    program1.addShader(vshader1);

    program1.addShader(fshader1);

    program1.link();

    vertexAttr1 = program1.attributeLocation("vertex");

    normalAttr1 = program1.attributeLocation("normal");

    matrixUniform1 = program1.uniformLocation("matrix");

    QGLShader *vshader2 = new QGLShader(QGLShader::Vertex);

    const char *vsrc2 =

        "attribute highp vec4 vertex;\n"

        "attribute highp vec4 texCoord;\n"

        "attribute mediump vec3 normal;\n"

        "uniform mediump mat4 matrix;\n"

        "varying highp vec4 texc;\n"

        "varying mediump float angle;\n"

        "void main(void)\n"

        "{\n"

        "    vec3 toLight = normalize(vec3(0.0, 0.3, 1.0));\n"

        "    angle = max(dot(normal, toLight), 0.0);\n"

        "    gl_Position = matrix * vertex;\n"

        "    texc = texCoord;\n"

        "}\n";

    vshader2->compileSourceCode(vsrc2);

    QGLShader *fshader2 = new QGLShader(QGLShader::Fragment);

    const char *fsrc2 =

        "varying highp vec4 texc;\n"

        "uniform sampler2D tex;\n"

        "varying mediump float angle;\n"

        "void main(void)\n"

        "{\n"

        "    highp vec3 color = texture2D(tex, texc.st).rgb;\n"

        "    color = color * 0.2 + color * 0.8 * angle;\n"

        "    gl_FragColor = vec4(clamp(color, 0.0, 1.0), 1.0);\n"

        "}\n";

    fshader2->compileSourceCode(fsrc2);

    program2.addShader(vshader2);

    program2.addShader(fshader2);

    program2.link();

    vertexAttr2 = program2.attributeLocation("vertex");

    normalAttr2 = program2.attributeLocation("normal");

    texCoordAttr2 = program2.attributeLocation("texCoord");

    matrixUniform2 = program2.uniformLocation("matrix");

    textureUniform2 = program2.uniformLocation("tex");

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );

    m_fAngle = 0;

    m_fScale = 1;

    createGeometry();

    createBubbles(bubbleNum - bubbles.count());

}

void GLWidget::paintGL()

{

    createBubbles(bubbleNum - bubbles.count());

    QPainter painter;

    painter.begin(this);

    painter.beginNativePainting();

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

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );

    glFrontFace(GL_CW);

    glCullFace(GL_FRONT);

    glEnable(GL_CULL_FACE);

    glEnable(GL_DEPTH_TEST);

    QMatrix4x4 modelview;

    modelview.rotate(m_fAngle, 0.0f, 1.0f, 0.0f);

    modelview.rotate(m_fAngle, 1.0f, 0.0f, 0.0f);

    modelview.rotate(m_fAngle, 0.0f, 0.0f, 1.0f);

    modelview.scale(m_fScale);

    modelview.translate(0.0f, -0.2f, 0.0f);

    if (qtLogo) {

        program1.bind();

        program1.setUniformValue(matrixUniform1, modelview);

        paintQtLogo();

        program1.release();

    } else {

        program2.bind();

        program1.setUniformValue(matrixUniform2, modelview);

        paintTexturedCube();

        program2.release();

    }

    glDisable(GL_DEPTH_TEST);

    glDisable(GL_CULL_FACE);

    painter.endNativePainting();

    if (m_showBubbles)

        foreach (Bubble *bubble, bubbles) {

            bubble->drawBubble(&painter);

    }

    QString framesPerSecond;

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

    painter.setPen(Qt::white);

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

    painter.end();

    swapBuffers();

    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);

    }

    for (int i = 0;i < vertices.size();i++)

        vertices[i] *= 2.0f;

}

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

{

    vertices << QVector3D(x1, y1, -0.05f);

    vertices << QVector3D(x2, y2, -0.05f);

    vertices << QVector3D(x4, y4, -0.05f);

    vertices << QVector3D(x3, y3, -0.05f);

    vertices << QVector3D(x4, y4, -0.05f);

    vertices << QVector3D(x2, y2, -0.05f);

    QVector3D n = QVector3D::normal

        (QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(x4 - x1, y4 - y1, 0.0f));

    normals << n;

    normals << n;

    normals << n;

    normals << n;

    normals << n;

    normals << n;

    vertices << QVector3D(x4, y4, 0.05f);

    vertices << QVector3D(x2, y2, 0.05f);

    vertices << QVector3D(x1, y1, 0.05f);

    vertices << QVector3D(x2, y2, 0.05f);

    vertices << QVector3D(x4, y4, 0.05f);

    vertices << QVector3D(x3, y3, 0.05f);

    n = QVector3D::normal

        (QVector3D(x2 - x4, y2 - y4, 0.0f), QVector3D(x1 - x4, y1 - y4, 0.0f));

    normals << n;

    normals << n;

    normals << n;

    normals << n;

    normals << n;

    normals << n;

}

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

{

    vertices << QVector3D(x1, y1, +0.05f);

    vertices << QVector3D(x2, y2, +0.05f);

    vertices << QVector3D(x1, y1, -0.05f);

    vertices << QVector3D(x2, y2, -0.05f);

    vertices << QVector3D(x1, y1, -0.05f);

    vertices << QVector3D(x2, y2, +0.05f);

    QVector3D n = QVector3D::normal

        (QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(0.0f, 0.0f, -0.1f));

    normals << n;

    normals << n;

    normals << n;

    normals << n;

    normals << n;

    normals << n;

}